Дисертації з теми "HEATING COIL"
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1
Xu, Tingting. "Feasibility study of inductive heating coil with distributed resonant capacitors." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/52897.
Повний текст джерелаАнотація:
Steam Assisted Gravity Drainage (SAGD) method is one of the most common methods used in the process of heavy oil recovery. However, the method is economically inefficient, inherently dependent of water availability and has some detrimental impact on the environment. Therefore the need for an efficient, economically feasible and environmental friendly solution to the existing problem is felt vehemently at the core of oil recovery industry. In the light of existing issue, electromagnetic heating technique has emerged as a promising solution and has received greater and greater attention of late. However, most of the studies (especially for inductive heating) have been limited to digital simulations and experiments primarily within the laboratory. In this thesis, preliminary investigations were carried out to confirm the feasibility of a new constructed capacitive compensated inductor coil. Design parameters of the inductor coil were computed and a test model was constructed in the lab for experimental verification of these parameters. The set up comprised a vertical drilling coil design with ferrite core inserted within, thus, creating an intensive electromagnetic field.
In this design, a distributed resonating capacitor was proposed to avoid capacitor breakdown due to high voltage. Different coil winding configurations were proposed, constructed and tested by Frequency Response Analysis (FRA) to identify the resonant frequencies. The step response tests and field tests were performed with a square wave supply and were contrasted with the expected induced magnetic field modeled in MatLab. The measurements of the designed coil parameters matched the theoretically computed parameters and the experimental setup verified the advantage of using distributed capacitors, resulting is low breakdown voltage requirement. However, double-layer winding has multiple resonant frequencies and the proposed coil designs suffer from core losses core and winding copper losses. Thus, industrial application of this technology still requires further improvements.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
2
Eisenstein, Jessica A. (Jessica Ann). "Design and construction of a Helmholtz coil apparatus for nanoparticle heating." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36307.
Повний текст джерелаАнотація:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (p. 50-51).
Manipulating biomolecules can lead to better understanding how specific biological components function and can result in new therapeutic techniques. Biomolecules are manipulated by magnetically heating conductive nanoparticles attached to biomolecules within a radio frequency magnetic field generated by a coil. Currently, researchers monitor the effectiveness of this heating with UV/Visible spectroscopy. However, fluorescence spectroscopy would provide a more sensitive and versatile way to monitor the effects of magnetic heating. By using a Helmholtz coil pair, I have successfully created a coil set-up that can manipulate a sample of biomolecules within a fluorometer.
by Jessica A. Eisenstein.
S.B.
3
BAKTASH, IMAN. "Modeling of Electromagnetic Heating of Multi-coil Inductors in Railway Traction Systems." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-11026.
Повний текст джерелаАнотація:
Inductors are frequently used in railway electrical tractions systems in filtering and current limiting operations. Magnetic fields are generated due to the flow of large AC currents through the coils, which intend induce currents on the coils as well as the metallic components in the vicinity, causing electromagnetic heating. The heating may cause temperatures to exceed project temperature requirements and in the worst case distort the functionality of drive system. The purpose of this work is to simulate the Electromagnetic Heating effect of inductors in 3D using COMSOL Multiphysics. First a 3D CAD model of the inductor geometry is imported to COMSOL and the magnetic fields for a giving current excitation are estimated. Then the power losses are fed in to a heat flow simulation to predict the temperature distributions. Cooling is simulated by driving cool air through the heated coils and the surrounding metal objects. The temperature distributions for different current excitations and air flow velocities are estimated. Simulation is performed on conceptual project inductor model. The 3D inductor modeling approach established in this thesis work could be used to characterize the electromagnetic heating issues early in the project design phase.
4
Deng, Shi-Ming. "Modelling and control of an air conditioning system with emphasis on cooling coil behaviour." Thesis, London South Bank University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303912.
Повний текст джерела
5
Durukan, Ilker. "Effects Of Induction Heating Parameters On Forging Billet Temperature." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608879/index.pdf.
Повний текст джерелаАнотація:
Induction heating is one of the efficient and modern technique for heating raw materials for hot forging process. The induction heating furnaces use electro-magnetic field to transfer energy to the metal workpiece and heat is generated inside the material. The magnetic field can be provided by using induction coil. The power supplied to induction coil, the moving speed of the billet that is called conveyor speed and the coil box hole diameter are the factors affecting the resultant temperature of the heated billet.
In this study, AISI 1045 type steel billets with a diameter of Ø30 mm and length of 100 mm have been heated in a particular induction heater. During heating, effects of different levels of power, conveyor speed and the coil boxes with different hole diameters are investigated. The 125 KW 3000 Hz induction heater which is available in METU-BILTIR Research and Application Center Forging Laboratory is used in experiments. The heating experiments are designed according to 23 Factorial Design of Experiment Method. Multiple linear regression technique is used to derive a mathematical formula to predict the temperature of the heated billet. A good correlation between the measured temperatures that are the results of different sets of induction heating parameters and the predicted temperatures that are calculated by using temperature prediction formula has been observed.
6
Dowrani, Ali Akbar Gharooni. "Efficiency of air cooler coil defrost methods and the effect of these methods on the refrigeration cycle performance." Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316876.
Повний текст джерела
7
Hiler, Marzena M. "THE INFLUENCE OF ELECTRONIC CIGARETTE HEATING COIL RESISTANCE ON NICOTINE DELIVERY, HEART RATE, SUBJECTIVE EFFECTS, AND PUFF TOPOGRAPHY." VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/5988.
Повний текст джерелаАнотація:
Electronic cigarette (ECIG) users can manipulate several device features including liquid nicotine concentration (mg/ml) and heating coil resistance (Ohms). One class of ECIG models, called “sub-Ohm” devices, use coils with a resistance of < 1 Ohms, lower than those observed in conventional ECIGs (e.g., ≥ 1.5 Ohms). Increasing voltage or decreasing coil resistance increases device power. Given that ECIG coil resistance and liquid nicotine concentration have not been manipulated systematically and simultaneously in clinical laboratory studies, the influence of these factors on ECIG acute effects remain unclear. The primary purpose of this study was to examine the influence of coil resistance and liquid nicotine concentration on nicotine delivery, heart rate (HR), subjective effects, puff topography, and liquid consumption.
Thirty-two experienced ECIG users completed four independent laboratory sessions that differed by coil resistance (0.5Ohm or 1.5Ohm ) and liquid nicotine concentration (3 or 8 mg/ml). In each session, participants used a 4.5 V “Kanger SUBOX” loaded with 3.5 ml ECIG liquid in a 10-puff directed and 60-minute ad libitum bout. Nicotine delivery was greatest when using 8 mg+0.5Ohm combination and lowest when using the 3 mg/ml+1.5Ohm combination and HR followed a similar pattern. Abstinence symptom suppression was most pronounced for the 8 mg+0.5Ohm combination and least pronounced for the 3 mg/ml+1.5Ohm combination. Participants provided the highest ratings for pleasantness, satisfaction, and liking of harshness/irritancy and throat hit sensations for the 3 mg+0.5Ohm combination. Overall, use of ECIGs filled with 3 mg/ml nicotine concentration resulted in longer/larger puffs, increased puff frequency, and greater consumption of ECIG liquid. ECIG coil resistance, liquid nicotine concentration, and user puff topography, all of which influence ECIG nicotine delivery, should be considered together when making regulatory decisions aimed at protecting public health.
8
Ertug, Muzeyyen Oya. "Computer Aided Design And Simulation Of Year Around Air Conditioning-comfort Application." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610356/index.pdf.
Повний текст джерелаАнотація:
The aim of this thesis is to develop a computer program to design and simulate air
conditioning-comfort application of a selected building, for a year period, on an
hourly basis. In order to carry out this study, a computer program named
AHUSIM.m, is prepared with Matlab computing language.
The design and simulation procedure starts with preparing the inputs like indoor,
outdoor design states, zone cooling and heating loads, along with the general data for
conditioning-comfort equipment. The program, in light of these input data, performs
the plotting of the psychrometric processes -including the design and off design
processes- on psychrometric charts, air conditioning-comfort system selection and
calculating the response of this selected system at varying load conditions for a year.
The program also calculates the energy requirements of parts of the selected system
throughout the year. Furthermore, it lists dimensions of the parts of the air
conditioning-comfort unit, the outdoor supply air and total air flow rates, air and
water inlet and exit states.
Using numerical tools for heating, ventilating and air conditioning (HVAC) process
design and simulation, can improve energy economy and comfort which are the main
criteria of HVAC engineering. In such an attempt, major concern is the interaction
between the comfort and energy consumption. The program, by designing the system
and deciding its behavior throughout a yearprovides a means of automatic control considering comfort and energy economy. This program also provides a tool for comparison of different techniques for putting limits to the relation between comfort and energy consumption.
9
Nevřela, Tomáš. "Přenosný zdroj pro indukční ohřev." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-376939.
Повний текст джерелаАнотація:
The aim of this work is to realize and test a prototype portable source for induction heating of small parts. The project contains a theoretical basis of resonant circuits and induction heating. The device design is based on simulation results from the FEMM program, with which a focussing coil for induction heating has been designed. The parts of the thesis are the realization of the designed device, its putting into operation and the programming of the control.
10
Fatemi-Badi, Seyed Mohammad. "Predicting the Self-Heating Potential of Coal." TopSCHOLAR®, 1985. https://digitalcommons.wku.edu/theses/2320.
Повний текст джерелаАнотація:
Self-heating in coal has been studied for well over one hundred years, yet there is no accurate or reliable method for predicting the potential of certain coals to undergo self-heating. Fires caused by self-heating, and eventually spontaneous combustion, have occurred in the high wall of surface mines, in underground mines, in coal stockpiles, and on trains, barges and ships. Self-heating in coal is brought about through a complex interplay of conditions depending on the specific properties of the coal as well as many external factors involved in the mining and handling of coal.
In a study supported by the United States Department of Transportation and monitored by the United States Coast Guard, data on over 2000 barges of coal was incorporated into a data bank. Results from the evaluation of these data and from a barging study, in which a research crew accompanied a tow of barges from western Kentucky to the New Orleans area, were used to make recommendations to minimize self-heating in barged coal.
An inexpensive adiabatic calorimeter (accelerating rate calorimeter) was constructed and used to obtain supporting
laboratory data on coal samples collected in the barging study. There is very good agreement between the results obtained with the calorimeter concerning the reactivity of coals and susceptibility of the coals to undergo selfheating as would be predicted using chemical and physical data from the data bank.
11
Azhakesan, M. "An investigation of coal gasification by rapid heating techniques." Thesis, University of Leeds, 1988. http://etheses.whiterose.ac.uk/2081/.
Повний текст джерела
12
Kalra, Aashish. "Dewatering of fine coal slurries by selective heating with microwaves." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4536.
Повний текст джерелаАнотація:
Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains xi, 84 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
13
Mill, Christopher John School of Chemical Engineering & Industrial Chemistry UNSW. "Pyrolysis of Fine Coal Particles at High Heating Rate and Pressure." Awarded by:University of New South Wales. School of Chemical Engineering and Industrial Chemistry, 2000. http://handle.unsw.edu.au/1959.4/33358.
Повний текст джерелаАнотація:
High-intensity pyrolysis, rapid heating in an inert gas atmosphere at up to 20 atm pressure, of 6 Australian coals was examined to gain further insight into high-intensity processes such as Integrated Gasification Combined Cycles (IGCC). Experiments focussed on pyrolysis in a specially developed Wire Mesh Reactor (WMR). The particle temperature lagged that of the mesh by 0.2 seconds at a heating rate of 100??~C s -1 and was predicted by modelling. This is part of the reason the volatile yield (VY) results for 10 s hold-time at ???b1.7 wt% daf of coal, is much more reproducible than 1 s hold-time experiments at ???b4.2 wt% daf of coal. Four coals of the same rank did not behave identically when heated. Three of the coals had a pyrolysis VY the same as the proximate VM when heated to 100??~C at 1 atm but the fourth, higher inertinite coal had a 1 atm pyrolysis VY 90% of its proximate VM. All four coals of similar rank had a significant decrease in VY, between 10 and 20 wt% daf of coal, with pressure increasing from 1 to 20 atm. The two lower rank coals showed less decrease in VY with increasing pressure than the higher rank and higher inertinite coals. The lower decrease in VY with increased pressure was mostly attributed to the lower inertinite levels for both the coals of similar rank and VM, and the coals of lower rank. Char characteristics examined focussed on pore Surface Area (SA). For high intensity WMR and Drop Tube Furnace (DTF) pyrolysis experiments CO2 SA for char from a particular coal was similar but the BET SA different. This was due to the char in the WMR experiments having longer to form larger pores determined by BET N2 SA. Both the N2 and CO2 SA was more than an order of magnitude greater than for low intensity pyrolysis char. This highlights that the WMR can be used to attain char with similar CO2 SA characteristics as other high intensity pyrolysis experiments and to provide a more meaningful insight into char reactivity than low intensity chars do.
14
Wardle, Peter. "The selective heating of pyrite in coal using microwave energy." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/12017/.
Повний текст джерелаАнотація:
The objective of this research project was to investigate the effect of microwave treatment on the conversion of pyrite in coal in order to enhance its magnetic properties and to aid subsequent desulphurisation by magnetic separation. Key areas of this investigation include:- a review of the fundamental theoretical aspects of heating in an applied microwave field, a detailed literature survey of the potential applications of microwave heating to aid coal desulphurisation, a study of the transformation mechanisms of pyrite by microwave and conventional heating methods, a comprehensive review of the influence of heterogeneity on the dielectric properties of coals and the effect of high power microwave heating on the decomposition of pyrite in a high sulphur coal. A detailed survey of the literature has shown that although a significant amount of work has been reported on the microwave heating of coal, little information is available which examines the mechanism through which different coals heat in an applied microwave field. A study is therefore presented in this thesis which quantifies, for the first time, the structural ordering of carbon in a range of coals of various ranks and the relationship with their dielectric properties. The results show a clear relationship between the structural ordering of carbon in coal and dielectric loss factor. Essentially, as the structural ordering increases, the level of free charge (per unit volume) increases together with electron mobility which results in an increase in dielectric loss factor. The transformation of pyrite to form the more magnetic pyrrhotite and other related decomposition products by conventional radiant heating has been the focus of much research. However, little attention has been given to the effect of microwave heating on the mechanisms of pyrite transformation in inert and oxygen-containing atmospheres. The study presented in this thesis investigates the effect of temperature, particle size and heat treatment time to establish how these affect the transformation process and the subsequent nature of the final product. This study showed that exposure of pyrite to both conventional and microwave heating methods enhanced its magnetic properties as a result phase alterations at the particle surface. Conventionally heated pyrite samples showed the highest magnetic susceptibility increases, speculated to be due difficulties surrounding the temperature control and measurement of the microwave heated samples. From a review of the literature in this field of research and by SEM observations made for each sample test in this work a general pyrite transformation model as a result of microwave exposure is proposed. The effect of microwave radiation on the conversion of in-situ coal derived pyrite was also investigated. The study presented here extends previous work by others by assessing quantitatively the influence of higher applied microwave power levels on the conversion of pyrite in coal. Samples of run-of-mine high pyritic sulphur content (~12%wt) Kentucky coal were microwave pre-treated at varying exposure times using 8kW and 15kW of microwave power operating at a frequency of 2.45GHz. This work included initial material characterisation which consisted of TGA, optical microscopy and dielectric property measurement, followed by SEM/EDAX characterisation of both microwave treated and untreated sample specimens. This is the first time that microwave treated coal, embedded in a carnauba wax mounting medium, has been observed by this method with focus on the thermal alterations of the pyrite phase. It was demonstrated that with sufficient power and residence time, the conversion of pyrite to the more magnetic pyrrhotite is achievable using microwave irradiation. The amount of pyrrhotite formed as a result of microwave exposure varies with microwave residence time and forward power level. Comparisons of change in the iron sulphide species in the coal was made between microwave treated and untreated material. Using a multimode microwave cavity it was found that significant amounts of pyrrhotite were formed in 20s when using 15kW of microwave power. Treatment at lower power levels in this type of cavity was found to be less effective. The overall effect of treatment on the coal proximate character was minimal.
15
Zeng, Dong. "Effects of Pressure on Coal Pyrolysis at High Heating Rates and Char Combustion." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd994.pdf.
Повний текст джерела
16
Al-Shaikhli, Ali K. M. "A novel method for the design of induction heating work coils." Thesis, Loughborough University, 1985. https://dspace.lboro.ac.uk/2134/27353.
Повний текст джерелаАнотація:
Induction billet heating is a well-established industrial process for preheating prior to forging, rolling and extrusion. In many cases the application of induction heating techniques has been hindered by the inability of existing methods of work coil design to easily produce a design which will give a non-uniform power density along the surface of a workpiece.
17
Parvez, Arshad. "Alkali Extraction Test as a Predictor for Self-Heating in Coal." TopSCHOLAR®, 1986. http://digitalcommons.wku.edu/theses/1817.
Повний текст джерелаАнотація:
The self-heating of coal is a serious problem that has always affected the coal industry. Self-heating has been studied around the world for more than 100 years by many investigators, yet no accurate method of predicting self-heating in coal has been developed.
The objective of this research was to investigate the factors contributing to the self-heating in coal and to develop methods to predict the self-heating in coal and to develop methods to predict the self-heating susceptibility of various coals. A data bank containing analytical data, transportation histories, and results from laboratory tests was established at Western Kentucky University. A laboratory test that gave very encouraging results is an extraction test using sodium hydroxide solutions. Absorbances of the extract solutions from 15 coal samples obtained from barges of coal shipped from the Illinois Basin coal fields to the New Orleans area compared very well with the incidences of self-heating in the 15 barges. The fact that these coals were shipped in the summer when conditions are more favorable for self-heating to take place may have led to the strong correlation of the alkali extract solution absorbances and the final temperatures of the coal in the barges. Tests with coal samples obtained from barges shipped in the other seasons of the year did not yield very good correlations. The poor correlation between self-heating and the alkali extraction test absorbances was due to the lack of accurate temperature data, since the temperature of the coal at the time of loading was not available. The correlation of the absorbances of the extract solutions with parameters such as Btu/lb, oxygen, sulfate sulfur, and free-swelling index was very good.
18
Benson, R. A. C. "Starting up coal-burning, fluidised-bed boilers." Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375523.
Повний текст джерела
19
Kennedy, Mark William. "Magnetic Fields and Induced Power in the Induction Heating of Aluminium Billets." Licentiate thesis, KTH, Materialens processvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-123783.
Повний текст джерелаАнотація:
Induction heating is a common industrial process used for the reheating of billets before extrusion or forging. In this work the influence of the coil and work piece geometry, the effect of the electrical properties of the work piece, and the coil current and frequency, on the magnetic flux density and resulting work piece heating rates were studied. A combination of 1D analytical solutions, 2D axial symmetric finite element modelling and precise measurements has been used. Dozens of heating and magnetic field experiments have been conducted, with steadily increasing sophistication and measurement accuracy. The development of the experimental techniques will be described in the ‘cover’ and related to the later results published in the supplements. Experimental results are compared to predictions obtained from analytical and numerical models. The published measurements obtained for the billet heating experiments consisted of: billet electrical conductivity with <0.5% error, applied currents with <1% error, magnetic flux densities with 1-2% error, calorifically determined heating rates with <2% error and electrical reactive power with <~2% error. 2 D axial symmetric finite element models were obtained, which describe the measured results with less than a 2% difference (i.e. an ‘error’ of the same magnitude as the measurement uncertainty). Heating and reactive power results predicted by the FEM model are in excellent agreement with analytical solutions from 50 Hz to 500 kHz (differences from <1% to 6%). A modified 1D short coil correction factor is presented which accounts for the interaction of the coil and work piece geometry, electrical properties and operating frequency, on the average magnetic flux density of the coil/work piece air-gap and the resulting heating rate. Using this factor, the average magnetic flux density in the air-gap can be estimated analytically within 2-3% and the heating rates of billets of known electrical properties can be estimated, with typical errors on the order of 5%.QC 20130618
20
Strugnell, Brian. "The influence of high heating rate hydropyrolysis on the primary devolatilisation of coal." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/13619.
Повний текст джерелаАнотація:
The hydropyrolysis of coal is considered to be an attractive future route for the conversion of coal to gaseous and liquid fuels and chemical feedstocks. This thesis comprises a study of the behaviour of coal under the conditions pertinent to those envisaged within a commercial hydropyrolysis process, that is, using pulverised coal, a short coal-reactor residence time, high hydrogen pressure and high heating rate. For this purpose, an electrically heated grid apparatus has been used. The experimental conditions have been weighted towards achieving a maximum loss of primary volatile products whilst minimising unwanted and poorly controlled secondary reactions such as char hydrogasification. In this way, it has been possible to compare the influence of a hydrogen atmosphere on primary devolatilisation for a range of coals. Overall, the total volatile release is enhanced by hydropyrolysis to a degree dependent upon the partial pressure of the hydrogen. The increased yield is due mainly to an increase of saturated hydrocarbons, although the production of some individual species such as carbon monoxide, carbon dioxide and unsaturated hydrocarbons are diminished with respect to helium pyrolysis. The magnitude of both total and individual product yields vary with coal type, as does the degree by which these yields are influenced by a hydrogen atmosphere. This influence is considered to depend specifically on the type and number of various reactive sites and functionalities within coal and also on their accessibility for hydrogen, which is in tum dependent upon the thermoplastic behaviour of the coal. A further factor governing both product yields and hydrogen influence is the coal petrographic composition. Inertinite macerals have been observed to be significantly more responsive than exinite or vitrinite to hydrogen, producing relatively high methane yields. Thus it has been shown that inertinite rich coals or enriched feedstocks may be suitable candidates for hydropyrolysis processing. The data obtained have also demonstrated how a number of coal properties obtained by standard analytical techniques may be used for coal selection and yield prediction. BS volatile matter, carbon content, vitrinite reflectance and both 0/C and H/C atomic ratios are the most useful of the properties investigated in this respect. This is considered to be an important step towards the foundation of a classification system for hydropyrolysis processing.
21
Gibbins, Jonathan Robert. "Investigation of primary coal pyrolysis processes using a variable heating rate wire-mesh apparatus." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/11278.
Повний текст джерела
22
Lewis, Aaron D. "Gasification of Biomass, Coal, and Petroleum Coke at High Heating Rates and Elevated Pressure." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4373.
Повний текст джерелаАнотація:
Gasification is a process used to convert any carbonaceous species through heterogeneous reaction to obtain the desired gaseous products of H2 and CO which are used to make chemicals, liquid transportation fuels, and power. Both pyrolysis and heterogeneous gasification occur in commercial entrained-flow gasifiers at pressures from 4 to 65 atm with local gas temperatures as high as 2000 °C. Many gasification studies have been performed at moderate temperatures, heating rates, and pressures. In this work, both pyrolysis and char gasification experiments were performed on coal, petroleum coke, and biomass at conditions pertinent to commercial entrained-flow gasifiers. Rapid biomass pyrolysis experiments were performed at atmospheric pressure in an entrained-flow reactor for sawdust, switchgrass, corn stover, and straw mostly using a peak gas temperature of 1163 K at particle residence times ranging from 34 to 113 ms. Biomass pyrolysis was modeled using the Chemical Percolation Devolatilization model assuming that biomass pyrolysis occurs as a weighted average of its individual components (cellulose, hemicellulose, and lignin). Thermal cracking of biomass tar into light gas was included using a first-order model with kinetic parameters regressed in the current study. Char gasification rates were measured for biomass, petroleum coke, and coal in a pressurized entrained-flow reactor at high heating-rate conditions at total pressures between 10 and 15 atm. Peak centerline gas temperatures were between 1611 and 1879 K. The range of particle residence times used in the gasification experiments was 42 to 275 ms. The CO2 gasification rates of biomass and petroleum coke chars were measured at conditions where the reaction environment consisted of approximately 40 and 90 mol% CO2. Steam gasification rates of coal char were measured at conditions where the maximum H2O concentration was 8.6 mol%. Measured data was used to regress apparent kinetic parameters for a first-order model that describes char conversion. The measured char gasification rates were far from the film-diffusion limit, and are pertinent for pulverized particles where no internal particle temperature gradients are important. The modeling and measured data of char gasification rates in this research will aid in the design and efficient operation of commercial entrained-flow gasifiers, as well as provide validation for both existing and future models at a wide range of temperatures and pressures at high heating-rate conditions.
23
Yuwardi, Yuwardi. "Absorption cooling in district heating network: Temperature difference examination in hot water circuit." Thesis, KTH, Kraft- och värmeteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-125068.
Повний текст джерелаАнотація:
Absorption cooling system driven by district heating network is relized as a smart strategy in Sweden. During summer time when the heating demand is low, the excessive hot water can be directly sold to drive absorption chillers instead of decreasing its production. In addition, this is also one answer to satisfy the cooling demand in more environmentally way since currently only around 26% of cooling demand in Sweden is satisfied by district cooling, the rest is fulfilled by individual air conditioning. Realizing this potential, the purpose of this study is to examine the returning hot water temperature in the district heating network with supply temperature of 70°C and also the effect to the absorption chiller’s COP. Through the simulation result, it is found out that the lowest possible returning water temperature is 55 °C at COP 0,69 with heat rejection (re-cooling) temperature water at 22 °C. This implies that the desired returning hot water temperature of 47 °C cannot be achieved. The lower returning hot water temperature is preferable since it gives the district heating network benefit in term of less distribution pump work, and energy recovery for the condensation process at central heating plant.
24
Santos, Enrique. "A Study of the Volatile Matter of Coal as a Function of the Heating Rate." TopSCHOLAR®, 1997. http://digitalcommons.wku.edu/theses/354.
Повний текст джерелаАнотація:
A study of volatile matter yields as a function of the heating rate was conducted. A suite of 21 coal and coke samples varying in rank from anthracitic to lignitic and heating rates from 10°C/min to about 450°C/min were used in the study. Heating rates up to 60°C per minute, which are typically used in ASTM Test Method 5142 (instrumental Proximate Analysis), were achieved in a macro thermogravimetric analysis (TGA) system. Heating rates of 50-200°C/min were obtained in a micro TGA system. All measurements were made in a nitrogen atmosphere. The results of the study illustrate the dependance of the volatile matter yield on the heating rate. For most coals and cokes the optimum heating rate for determining volatile matter values that agree with those obtained by ASTM Method D 3175 appears to be in the 100-150°C range.
25
Zhang, Tianyao. "A study on the heat transfer and energy performance implications of cool roofs." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52977.
Повний текст джерелаАнотація:
In this study, we examined the effect of cool roofs on commercial and residential buildings in each climate zone, by looking at monitored case studies and DOE-2 simulations from various sources of literature; and using an online tool - the Cool Roof Calculator and a simple COP ratio model to validate the results of the case studies. It was found that the Cool Roof Calculator does not take building form into account, hence a sensitivity analysis was first conducted to rank the importance of various building parameters against one another. The analysis was conducted on the EPC normative building energy model. Results indicated that roof absorptance coefficient, aspect ratio and number of floors were the three parameters that either ranked highest or were important parameters, and were chosen for further parametric analysis to evaluate the impact of these building parameters on total building loads.
A simple COP ratio model was also developed to validate the results from the literature review and Cool Roof Calculator, and it was found that in terms of cost, for a prototype medium-sized commercial building, it is always beneficial to use a white roof, but cities in northern climates may have little advantage, and insulation may be a better
choice.
26
Juříček, Vlastimil. "Analýza současného stavu a rizik pro další vývoj teplárenství v ČR." Master's thesis, Vysoká škola ekonomická v Praze, 2014. http://www.nusl.cz/ntk/nusl-192747.
Повний текст джерелаАнотація:
The goal of the thesis is identification and analysis of key risks for Czech district heating sector with focus on coal availability and impact of the EU regulatory measures. In the Czech Republic district heating sector is an important part of energy industry. It serves heating needs of 1.5 million households and substantial amount of industry needs. Currently the question of possible brown coal shortage is becoming urgent. Dynamically changing regulatory framework generating requirements for additional investments is destabilizing. The sector is defined, its competitiveness is evaluated and further the risks are analyzed. Based on brown coal market analysis it is concluded that the current market situation can be considered as stabilized. In the long term perspective the question of possible lifting of the coal mining limits remains crucial. It is concluded that impacts of the EU regulatory measures can't be objectively evaluated at the moment. But it can be assumed that most of district heating companies will be finally able to meet the requirements.
27
Shurtz, Randy C. "Effects of Pressure on the Properties of Coal Char Under Gasification Conditions at High Initial Heating Rates." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2877.
Повний текст джерелаАнотація:
The effects of elevated pressure and high heating rates on coal pyrolysis and gasification were investigated. A high-pressure flat-flame burner (HPFFB) was designed and built to conduct these studies. The HPFFB was designed to provide an environment with laminar, dispersed entrained flow, with particle heating rates of ~10^5 K/s, pressures of up to 15 atm, and gas temperatures of up to 2000 K. Residence times were varied from 30 to 700 ms in this study. Pyrolysis experiments were conducted at particle heating rates of ~10^5 K/s and maximum gas temperatures of ~1700 K at pressures of 1 to 15 atm. A new coal swelling correlation was developed that predicts the effects of heating rate, pressure, and coal rank on the swelling ratio at heating rates above ~10^4 K/s. A coal swelling rank index system based on 13C-NMR chemical structural parameters was devised. The empirical swelling model requires user inputs of the coal ultimate and proximate analyses and the use of a transient particle energy balance to predict the maximum particle heating rate. The swelling model was used to explain differences in previously reported bituminous coal swelling ratios that were measured in facilities with different heating rates. Char gasification studies by CO2 were conducted on a subbituminous coal and 4 bituminous coals in the HPFFB. Pressures of 5, 10, and 15 atmospheres were used with gas compositions of 20, 40, and 90 mole % CO2. Gas conditions with peak temperatures of 1700 K to 2000 K were used, which resulted in char particle temperatures of 1000 K to 1800 K. Three gasification models were developed to fit and analyze the gasification data. A simple 1st-order model was used to show that the measured gasification rates were far below the film-diffusion limit. The other two models, designated CCK and CCKN, were based on three versions of the CBK models. CCKN used an nth-order kinetic mechanism and CCK used a semi-global Langmuir-Hinshelwood kinetic mechanism. The two CCK models fit the HPFFB gasification data better than the 1st-order model. The fits of the gasification data with CCK and CCKN were comparable to each other. The fit of the data in CCK suggests that Knudsen diffusion may have influenced the gasification rates in the HPFFB experiments. The gasification rate parameters in each of the three models were correlated with coal rank. 13C-NMR parameters were used to estimate a structural parameter of the coal char. Char-CO2 gasification rate coefficients correlated better with this NMR-based char structure index than it did with the carbon and oxygen content of the parent coal.
28
Tanik, Ahmet, and Richard Schedin. "Golvvärme eller radiatorer : Vattenburna värmesystem i flerbostadshus." Thesis, KTH, Byggteknik och design, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215314.
Повний текст джерелаАнотація:
I flerbostadshus är radiatorer det vanligaste uppvärmningssystemet. Inte alls många har golvvärme i deras lägenheter. I dagens nyproduktion av flerbostadshus bygger man för det mesta husen med radiatorer och har elburen golvvärme som komfortvärme i badrummen. I villor är det däremot mycket vanligare att man använder sig av vattenburen golvvärme över större delen av huset. Detta examensarbete undersöker varför det inte används golvvärme lika mycket i flerbostadshus, det undersöker även intresset för privatpersoner att ha golvvärme i lägenheter samt om dessa personer isåfall hade kunnat tänka sig betala mer pengar om de fick vattenburen golvvärme installerat vid nyproduktion.Resultaten har fåtts fram genom en enkätundersökning samt intervjuer där vi intervjuat kunniga inom området. Våra resultat visar att nästan 40% av de enkät intervjuade hade velat ha endast golvvärme som uppvärmningssystem medan ungefär 55% hade velat ha både radiatorer och golvvärme som ett gemensamt uppvärmningssystem. De flesta hade då velat ha golvvärme i bland annat toalett, badrum, hall, kök, vardagsrum och sovrum. Resultaten visar även att nästan hälften av de enkät besvarande hade kunnat tänka sig betala mer för en bostad med golvvärme medan den större delen av den andra hälften var osäkra och förmodligen behövde mer tid för att tänka. Resultaten gällande varför man inte använder vattenburen golvvärme i lägenheten lika ofta som man använder radiatorer visade sig variera lite mellan de intervjuade vilket vi tror har med erfarenheter att göra men att ett golvvärmesystem var installationsmässigt dyrare än ett radiatorsystem verkade vara huvudsaken.In prefabricated apartment blocks the most common thing people have in their homes is radiators as their waterborne heating system but very few have underfloor heating in their apartments. Nowadays the most usual thing to do is to install radiators and have underfloor electric heating in the bathrooms. Most residentials however usually have waterborne underfloor heating across the bigger part of the house. This report digs into why underfloor heating isn’t being used as often in apartment buildings, it also investigates people’s interest to have underfloor heating in apartment buildings plus if they then would be interested in paying more for a new apartment with waterborne underfloor heating.The outcome from our results has been achieved through a survey and interviews where we have questioned competent persons within the sector. Our results show that 40% of the people in the survey would like to have only underfloor heating as their waterborne system while 55% of the people would like to have a combined system with both radiators and underfloor heating. Most of them preferred to have underfloor heating in their toilets, bathrooms, entrance hall, kitchen, living room and bedroom. The results also show that almost half the persons in the survey could pay more money for a place with underfloor heating while the bigger part of the other half weren’t sure and probably needed more time to think. Our outcome on why waterborne underfloor heating in apartment buildings isn’t being used as often as radiators showed to differ between the interviewed persons which we assume have to do with their different backgrounds and experience but the main reason seemed to do with the part that a waterborne underfloor heating system in an installation point of view is more expensive than a radiator system.
29
Muangthong-On/Trairat. "Effect of Solvent on the Degradative Solvent Extraction of Low Rank Coal and Examination of Propensity to Spontaneous Heating of the Solvent Treated Coal and Residue." Kyoto University, 2009. http://hdl.handle.net/2433/227654.
Повний текст джерела
30
Parry, T. W. "Local authorities' use of coal : Financial, technical and attitudinal factors affecting the selection of coal as a space heating fuel in Local Authorities' non-domestic premises." Thesis, University of Bradford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379890.
Повний текст джерелаАнотація:
This research investigates financial, technical and attitudinal factors affectine the selection of coai as a space heating fuel in Local Authorities' non-domestic premises. Financial factors are explored by incorporating statistics of a sample of The City of Bradford Metropolitan Council's sites into a computer model that takes into account: the spread of capital costs of installing coal or other fuels. delivered fuel costs. maintenance and operating costs. and seasonal boiler efficiencies. The sensitivity of the mooei to changes in costs. boiler efficiencies. and financial selection criteria are investigated. Assuming a five year payback criterion and prices as found at the end of 1966, three percent of the space-heating ruel use or the Local Authority's premises is found to be viable for coal. The model is sensitive principally to changes in capital costs. and the availability of gas if a high cost for oit is assumed. Technical tactors are investigated by describing the properties or coal ana available comoustion equipment. Attitudes to the use of coal are researched by interviewing a sample of otticers and members in six Local Authorities in Yorksnire ana Humberside. Interviewees were particularly encouraged to describe their impressions and beliels. The scope of the study is expanded by the use of a postal survey of all United Kingdom Local Authorities. A variety or different topics are considered in the survey. These include the presence and content of fuel selection policies. the use and cost of fuels. financial criteria adopted in assessing projects, availability fr as supplies, and attitudes to the use of coal. The response rate to the questionnaire was over 40%. The study concludes with recommendations to The City or Braotora Metropolitan Council and British Coal.
31
Muangthong-On, Trairat. "Effect of Solvent on the Degradative Solvent Extraction of Low Rank Coal and Examination of Propensity to Spontaneous Heating of the Solvent Treated Coal and Residue." Doctoral thesis, Kyoto University, 2017. http://hdl.handle.net/2433/227654.
Повний текст джерелаАнотація:
京都大学0048
新制・課程博士
博士(エネルギー科学)
甲第20731号
エネ博第359号
新制||エネ||70(附属図書館)
京都大学大学院エネルギー科学研究科エネルギー応用科学専攻
(主査)教授 大垣 英明, 教授 松田 一成, 教授 河瀬 元明
学位規則第4条第1項該当
Doctor of Energy Science
Kyoto University
DFAM
32
Athresh, Anup. "Feasibility of using the water from the abandoned and flooded coal mines as an energy resource for space heating." Thesis, Nottingham Trent University, 2017. http://irep.ntu.ac.uk/id/eprint/32936/.
Повний текст джерелаАнотація:
This research project aims to study the feasibility of using the water from the abandoned and flooded coal mines for space heating applications using a Ground Source Heat Pump (GSHP) in open loop configuration and take a conceptual idea to a commercial deployment level. The flooded coal mines are the legacy that has been left behind after the three centuries of continuous operations by the coal mining industry. The closure of all coal mines in the UK has led to the flooding of all those abandoned underground workings and due to the subsequent rise in the water levels; mine water is posing a threat to the water table. Mine water in the abandoned coal mines can be considered as a low enthalpy energy resource with very little practical applications, however it can be upgraded to a high enthalpy resource by using a heat pump and used for heating applications. Heat pumps are considered as low carbon heating systems, using them for the space heating purpose is economically and environmentally beneficial compared to the conventional heating systems. A generic methodology has been developed to help in evaluating the process of harnessing the energy from mine water for the heating applications using an open loop GSHP. The methodology covers the core technical, environmental and economic aspects. An MS Excel based tool has been developed to assist in the design and commercial evaluation of a mine water based heating system. Financial model is created using Discounted Cash Flow (DCF) method to analyse the feasibility of implementing the system. Theoretical case studies have been conducted for three different sites using the software tool. Two pilot plants have been constructed at two different sites, namely at Markham, Alkane Energy and at Caphouse, National Coal Mining Museum (NCM) for the experimental work. The field trials from the two pilot plants show promising results in terms of reducing both the operating costs and carbon emissions. It also shows that with a careful design, the threat posed by mine water to the operations and maintenance of the plant can be minimised. The three theoretical case studies conducted show that the energy from the flooded coal mines is a good alternative source for heating and can contribute significantly in reducing the operating costs and the carbon emissions at those proposed sites. The abandoned mines underlie large parts of UK and at many sites, the water is being pumped out to prevent it from coming in contact with the water table and pollute the water bodies, these sites are ideal to implement the mine water based heating system, as they can support large thermal loads. The energy from the flooded coal mines is ideal to supplement or even replace the conventional sources of heating, as it is reliable and contributes to a reduction in carbon emissions and operating costs. Even though the initial capital costs are higher than other conventional heating systems, it becomes economically feasible with a good payback period, when additional financial incentives in the form of Renewable Heat Incentive (RHI), currently being offered by the government for GSHP technology, is taken into consideration. This research work shows that the energy from the mine water can be profitably harnessed to heat the buildings. The unique design developed to design the system, achieves continuous operation and minimises the maintenance requirements, even when a heavily polluted water is used.
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Najarzadeh, Amir E. "EVALUATION AND PREVENTION OF SPONTANEOUS COMBUSTION DURING HANDLING AND STORAGE OF COAL." UKnowledge, 2018. https://uknowledge.uky.edu/mng_etds/39.
Повний текст джерелаАнотація:
Spontaneous combustion of coal has historically been a major problem for the coal industry, predominantly during storage and transportation. Various methods have been used in the laboratory for evaluating the propensity of different coal sources to self-heat. However, the heterogeneity of coal and the complexity of the system has resulted in inconsistencies and sometimes conflicting results as indicated by the findings reported in several publications.
The primary objective of the current study was to build a laboratory scale apparatus that simulates the condition of a coal stockpile to evaluate the events leading to spontaneous combustion and develop potential remedies. As such, the influential factors can be identified with confidence, thereby providing an improved understanding of the spontaneous combustion.
An adiabatic heating apparatus was designed and constructed which included instrumentation to closely monitor the oxidation process and the stages leading to spontaneous combustion under various conditions. The device was equipped with thermocouples which measured the temperature rise as a function of time leading to the determination of an index value that indicated the propensity of a given coal source to spontaneously combustion. The index was referred to as the R70 value which was measured as the temperature was increased during the period of rapid oxidation. The units for the index was degrees Celsius per hour. As such, a high index value reflected the likelihood of spontaneous combustion for a given coal source.
To standardize the test procedure, a detailed three-level statistical experimental design was conducted involving three critical parameters, i.e., particle size, oxygen flow rate and the duration of the drying period prior to feeding oxygen to the system. Using empirical models describing the R70 value as a function of the parameter values developed from the test data, it was determined that R70 was sensitive to the sample particle size and drying time. A decrease in particle size and drying time significantly increased the R70 value while the oxygen rate did not have a significant impact over the range of values tested. Based on the results of the test program, a standard test procedure was established to evaluate various coal sources and identify chemicals that could be used to remediate the spontaneous combustion issue.
Several sub-bituminous coal sources collected from the Powder River Basin were tested in the apparatus and found to be prone to spontaneous combustion as indicated by R70 values that approached 50oC per hour. Several chemicals were evaluated as a means of eliminating or slowing the spontaneous combustion process. These agents included anti-oxidants, binders and humectants. Organic binders were used to agglomerate the fine coal particles which limited surface area exposure. The effect significantly reduced the oxidation rate as indicated by a reduction in the R70 index from 44.07oC/hr to 5.71oC/hr. However, after entering the latent heat stage, the temperature increased rapidly at a rate of 27.58oC/hr. Humectants were evaluated which contained several hydrophilic groups, mainly hydroxyl groups, and thus have an affinity for water. As a result, when the coals were treated with humectant, the latent heat rate was reduced to 4.24oC/hr although the R70 remained relatively high. By using a combination of humectant and binder, the optimum result was obtained with an R70 value of 5.04oC/hr and a latent heat rate of 11.06oC/hr. These findings were successfully implemented into industrial practice for significantly delaying the spontaneous combustion event.
34
Rahman, Mohammad W. "GEOCHEMISTRY OF THERMALLY ALTERED COALS AND ORGANIC-RICH SHALES: THE IMPACT OF RAPID HEATING ON PHYSICAL AND CHEMICAL PROPERTIES OF ORGANIC MATTER." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/dissertations/901.
Повний текст джерелаАнотація:
Igneous intrusion can change the geochemical and petrographic properties of sedimentary organic matter (such as coals and organic-rich clays or shales) including vitrinite reflectance, maceral petrographic composition, mineralogy, stable isotope composition, trace element composition, and bulk geochemistry. Igneous intrusions into coals and organic-rich rocks may have contributed to global warming in the geologic past by causing the release of greenhouse gases. Evidence for the release of large amounts of thermogenic CH4 from the organics would include significant;13Corg enrichment in the residual organic matter. However, 13Corg of thermally altered organic matter in coals and shales adjacent to intrusions often show negative shifts and, in some cases, ambiguous or positive trends. Previous studies have evaluated 13Corg of bulk samples rather than that of individual components, or macerals. As different macerals have different isotopic compositions, maceral-specific trends may be masked by variations in maceral composition of the whole-coal samples. It is important to explain the evolution of different geochemical and petrographic signatures in coals, coals macerals, and organic-rich sedimentary rocks close to an intrusion. This study evaluates the following three hypotheses: (1) thermally altered coals show different geochemical trends compared with coals that have undergone normal burial maturation; (2) if a large-scale release of 13C-depleted thermogenic CH4 resulted from intrusion of the coal, then it should have produced 13C-enriched coal and vitrinite macerals (the most abundant components of the coal) adjacent to the intrusion due to the release of light gases; and (3) 13Corg gets heavier with the increase in heat alteration approaching an intrusion due to the release of isotopically light gases. The current study reports petrographic, bulk geochemical (proximate, and ultimate), 13Corg data (whole-coal/shale samples and vitrinite macerals separated via density-gradient centrifugation, (DGC)), density data (vitrinite macerals), and Rock-Eval pyrolysis data for occurrences of thermally altered Springfield (No. 5) Coal (Pennsylvanian), Danville (No. 7) Coal (Pennsylvanian), and an organic-rich shale in the southern part of the Illinois Basin. Petrographic analysis shows an increase in vitrinite reflectance (Rm) from background levels of 0.55% up to ~4.80% in the Springfield (No. 5) Coal, 0.66% to 4.40% in the Danville (No. 7) Coal, and 0.71% to 4.78% for organic-rich shale; a loss of liptinite macerals, formation of isotropic coke and, at the intrusion contact, even development of fine-grained mosaic anisotropic coke texture. Volatile matter (VM) content decreases and fixed carbon (FC) content, ash, and mineral matter increase approaching the coal/intrusion contact. Carbon increases whereas nitrogen, hydrogen, and oxygen decrease approaching the intrusions. The presence of carbonate minerals (confirmed by X-ray diffraction and petrographic analysis) has a significant impact on proximate and ultimate data. However, even after removal of carbonates, trends for VM vs. vitrinite reflectance, %C vs. Rm, and H vs. C do not follow typical trends associated with normal burial coalification. Approaching the contacts, free oil content (S1), remaining hydrocarbon potential (S2), carbon dioxide from pyrolysis of the organic matter (S3), and hydrogen (HI) and oxygen (OI) indices decrease whereas thermal maturity (Tmax, ⁰C) increases. In addition, HI vs. VM, S2 vs. Rm, and Tmax vs. Rm diverge from pathways seen in previous studies. Trends in most of the Rock-Eval parameters in the organic-rich shale studied here are less clear due to the degree of variation in organic matter content, but a clear increase in thermal maturity (Tmax, C) is seen. There are no significant changes in 13Corg in the whole-coal samples (WCM) of the Springfield (No. 5) Coal (-25.28 / to -24.88 /), Danville (No. 7) whole coals (-25.37 / to -24.76 /), and in the DGC-separated vitrinites (-25.33 / to -24.96 /) of the Springfield (No. 5) Coal approaching the intrusion. However, the organic-rich shale transect shows a 1.31 / positive shift in 13C (from -25.06 / to -23.87 /) approaching the intrusion. DGC-separated vitrinite densities range from 1.268 g/mL in the unaltered coal to 1.523 g/mL at the coal/intrusion contact. For the vitrinite concentrates, density shows a clear correlation with Rm, %Cdaf, Hdaf, H/C, TOC, and 13Corg. These geochemical data suggest that these coals may have followed a different maturation track because of the geologically rapid heating associated with the intrusive event. It is also suggested here that the natural coke textures produced by such rapid geological heating may differ from those observed for metallurgical cokes produced under standard industrial coking conditions. Typically, in an industrial coke oven, a coal of this initial rank (Ro = ~ 0.6%) would produce an isotropic coke, rather than the fine-grained circular anisotropic coke seen here. The development of this texture may reflect differences due to heating rates or, alternatively, may indicate "pre-heating" of the coal during the intrusion event. Changes in the isotopic signatures are not of a magnitude that would be expected if significant thermogenic CH4 had been generated by the intrusive event. Moreover, there is no petrographic evidence for condensed or immobilized thermal products due to rapid pyrolysis (12C-rich pyrolytic carbon) close to the intrusion. These geochemical and petrographic data suggest there was only minimal CH4 generation associated with the rapid heating of the coals and organic-rich sedimentary rocks by the intrusion. In addition, there is no evidence for 13C-depleted condensed gas or pyrolytic carbon at the intrusion contact that could have moderated the isotopic signature. These data agree with previously reported data from this laboratory (Rahman et al., 2014, in review) and others (Gröcke et al., 2009; Yoksoulian, 2010) that indicate no clear evidence for large-scale CH4 generation due to the rapid heating or igneous intrusion in coals or sedimentary rocks.
35
Korolija, Ivan. "Heating, ventilating and air-conditioning system energy demand coupling with building loads for office buildings." Thesis, De Montfort University, 2011. http://hdl.handle.net/2086/5501.
Повний текст джерелаАнотація:
The UK building stock accounts for about half of all energy consumed in the UK. A large portion of the energy is consumed by nondomestic buildings. Offices and retail are the most energy intensive typologies within the nondomestic building sector, typically accounting for over 50% of the nondomestic buildings’ total energy consumption. Heating, ventilating and air conditioning (HVAC) systems are the largest energy end use in the nondomestic sector, with energy consumption close to 50% of total energy consumption. Different HVAC systems have different energy requirements when responding to the same building heating and cooling demands. On the other hand, building heating and cooling demands depend on various parameters such as building fabrics, glazing ratio, building form, occupancy pattern, and many others. HVAC system energy requirements and building energy demands can be determined by mathematical modelling. A widely accepted approach among building professionals is to use building energy simulation tools such as EnergyPlus, IES, DOE2, etc. which can analyse in detail building energy consumption. However, preparing and running simulations in such tools is usually very complicated, time consuming and costly. Their complexity has been identified as the biggest obstacle. Adequate alternatives to complex building energy simulation tools are regression models which can provide results in an easier and faster way. This research deals with the development of regression models that enable the selection of HVAC systems for office buildings. In addition, the models are able to predict annual heating, cooling and auxiliary energy requirements of different HVAC systems as a function of office building heating and cooling demands. For the first part of the data set development used for the regression analysis, a data set of office building simulation archetypes was developed. The four most typical built forms (open plan sidelit, cellular sidelit, artificially lit open plan and composite sidelit cellular around artificially lit open plan built form) were coupled with five types of building fabric and three levels of glazing ratio. Furthermore, two measures of reducing solar heat gains were considered as well as implementation of daylight control. Also, building orientation was included in the analysis. In total 3840 different office buildings were then further coupled with five different HVAC systems: variable air volume system; constant air volume system; fan coil system with dedicated air; chilled ceiling system with embedded pipes, dedicated air and radiator heating; and chilled ceiling system with exposed aluminium panels, dedicated air and radiator heating. The total number of models simulated in EnergyPlus, in order to develop the input database for regression analysis, was 23,040. The results clearly indicate that it is possible to form a reliable judgement about each different HVAC system’s heating, cooling and auxiliary energy requirements based only on office building heating and cooling demands. High coefficients of determination of the proposed regression models show that HVAC system requirements can be predicted with high accuracy. The lowest coefficient of determination among cooling regression models was 0.94 in the case of the CAV system. HVAC system heating energy requirement regression models had a coefficient of determination above 0.96. The auxiliary energy requirement models had a coefficient of determination above 0.95, except in the case of chilled ceiling systems where the coefficient of determination was around 0.87. This research demonstrates that simplified regression models can be used to provide design decisions for the office building HVAC systems studied. Such models allow more rapid determination of HVAC systems energy requirements without the need for time-consuming (hence expensive) reconfigurations and runs of the simulation program.
36
Nansalmaa, Erdenekhuu. "Evaluation on Health Impact of Government Support for GER (Traditional Dwelling) District's Electricity Night Rates in Ulaanbaatar City." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/iph_theses/161.
Повний текст джерелаАнотація:
During the last 10 years, air pollution has become one of the major public health problems in Ulaanbaatar city of Mongolia, and concentrations of pollutants were measured 3 to 50 times higher than WHO recommendation. This devastating air pollution is produced mostly by thousands of families who migrated from countryside and live in gers (traditional dwellings) in the suburban area which is not connected to the central heating system, and nearly all of them burn coal to keep them warm. Due to air pollution, residents living in Ulaanbaatar city suffer health problems that equal to the smoking of 4-5 packs of cigarettes. During the winter time, PM10 hourly average concentrations increased to 2,300 μg/m3, and daily average became over than 1,000 μg/m3 in the most polluted parts of the city. At present, Mongolian government has accepted that the health of Mongolian residents has deteriorated at an alarming level.
In January of 2011, Mongolian Parliament approved the Law on Reduction of Air Pollution in the Capital City to control air pollution and eliminate the gaps in practice. One main provision of this law was to improve ger district electricity transmission and distribution network and reduce the night-time price of electricity by 50 percent. Therefore, this study aimed to estimate direct health benefits of Government Provision on cutting electricity payment by 50 percent during the night time and analyze the efficiency of this program on reducing air pollution and its related health impact.
The study result showed when this new regulation is fully implemented in the ger districts, the annual consumption of coal and wood would be decreased by about 550,000 tons and 415,000 tons, accompanied by massive reduction of the emission. These changes would lead into noteworthy health benefits such as 15.7 and 17.4 percent of reduction of total and infant mortality rates and 4.3 and 4.7 percent decrease of cardiovascular and respiratory disease morbidity cases, annually.
37
Kasler, David R. "Effects of Moderate Electric Field Plus Heat Pretreatment on Bacterial Inactivation in Whole Shell Hen Eggs by Ozone." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1434445830.
Повний текст джерела
38
Buzrul, Sencer. "High Hydrostatic Pressure (hhp) Applications In Food Science: A Study On Compression Heating, Microbial Inactivation Kinetics, Pulsed Pressure And High Pressure Carbon Dioxide Treatments." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12609466/index.pdf.
Повний текст джерелаАнотація:
In this study the action of high hydrostatic pressure (HHP) on compression heating of liquid foods and pressure transmitting fluids, inactivation of Escherichia coli and Listeria innocua in different food media (milk and fruit juices), pulsed pressure and high pressure carbon dioxide treatments was investigated.
The experimental results in this study allowed pointing out some important results:
(i) The thermal effects of compression should be taken into account when HHP pasteurization processes are developed. Initial temperature of the food product and compression rate should carefully be selected in order to compensate the compression heating(ii) The HHP inactivation kinetics need not follow traditional first-order kinetics, hence alternative inactivation models are ought to be found. Weibull model can be used for HHP inactivation kinetics of microorganisms
(iii) The pulsed pressure treatment could be an alternative to continuous HHP, but optimization should be done between the pulse holding time, the number of pulses and the pressure level to reach the desirable number of log-reduction of microorganisms (E. coli and L. innocua) compatible with an industrial application
(iv) The storage duration and storage temperature after HHP treatment should carefully be optimized to increase the safety of HHP treated fruit juices since the growth of injured microorganisms can be avoided during storage
(v) The high pressure carbon dioxide (HPCD) treatment in combination with pulsed pressure can be an efficient way to inactivate the microorganisms in skim milk and to reduce the maximum pressure level for the desired log-reduction.
39
Sampaio, Igor Almeida. "Comportamento mecânico e acústico em arenitos submetidos ao ciclo de aquecimento e resfriamento." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/186130.
Повний текст джерелаАнотація:
Com o aumento crescente das restrições ambientais acompanhado do aumento crescente da demanda energética e matéria-prima pela população que cresce em proporções assustadores com poucos indícios de sua descida fizeram com que buscassem alternativas com viabilidade econômica e reduzisse os impactos ambientais. Para o carvão mineral, a alternativa encontrada é a Gaseificação do Carvão em Subsolo. Das vantagens encontradas com o processo, as mais interessantes são: a segurança operacional e pouca infraestrutura necessária, competitividade no preço do produto gerado (gás sintético) e pouco gerenciamento do rejeito produzido já que as cinzas são deixadas nas cavidades em subsolo. Uma das dificuldades encontradas é mostrar a mudança do comportamento mecânico e acústicos das rochas e maciço rochoso quando submetido a alta temperatura ou pós-operacional com o resfriamento das cavidades geradas durante o processo. O maciço rochoso, o sistema de fraturas e as suas propriedades mecânicas (resistência à compressão e resistência à tração) e as propriedades física (permeabilidade e anisotropia) influênciam o design operacional do processo. Com os resultados obtidos foi possível uma interdependência linear entre as velocidades das ondas P e S, essa mesma interrelação foram observadas antes e depois do ciclo de aquecimento e resfriamento com coeficiente de determinação (R²) de 0,9177 e 0,9472, respectivamente. As velocidades das ondas P e S são reduzidas com a temperatura. A redução é mais evidente na onda P com redução máxima de 39% do valor inicial. A velocidade da onda S é reduzida continuamente a partir dos 800°C, passando de 7 % para 3% da velocidade inicial. A regressão feita com a resistência à compressão dos ensaios triaxiais diverge dos resultados obtidos nos ensaios uniaxiais. Os resultados da resistência à tração e os de resistência à compressão apresentaram aumento e redução da resistência em diferentes temperaturas. A resistência à compressão não apresentou qualquer regressão com as velocidades ultrassônicas, enquanto que o módulo de Elasticidade estático apresentou uma regressão linear crescente com a velocidade da onda P com coeficiente de determinação (R²) de 0,7922.With the increasing increase of environmental restrictions, accompanied by an increasing increase in energy and raw material demand by the population that grows to frightening proportions with little evidence of their descent, they have sought to find alternatives with economic viability and reduce environmental impacts. For coal, the alternative found is Coal Gasification in Subsoil. Of the advantages found in the process, the most interesting are: operational safety and little infrastructure required, competitiveness in the price of the product generated (synthetic gas) and little management of the waste produced since the ashes are left in the underground cavities. One of the difficulties is to show the change in the mechanical and acoustic behavior of rocks and rock mass when submitted to high temperature or postoperational with the cooling of the cavities generated during the process. The rock mass, the fracture system and its mechanical properties (compressive strength and tensile strength) and physical properties (permeability and anisotropy) influence the operational design of the process. With the results obtained, a linear interdependence between the P and S velocities was possible. This same interaction was observed before and after the heating and cooling cycle with coefficient of determination (R²) of 0,9177 and 0,9472, respectively. P and S wave velocities are reduced with temperature. The reduction is more evident in the P wave with a maximum reduction of 39% of the initial value. The S wave velocity is continuously reduced from 800 ° C, from 7% to 3% of the initial velocity. The compressive strength with the triaxial tests differs from the results obtained in the uniaxial tests. The results of the tensile strength and the compressive strength showed increase and reduction of the resistance with different temperatures. The compressive strength did not show any regression with the ultrasonic velocities, while the static elasticity modulus presented an increasing linear regression with the P-wave velocity with determination coefficient (R²) of 0,7922.
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Menacer, Youcef. "Mécanisme membranotrope de l'ovotransferrine sur membranes modèles de bactéries : impact du chauffage à sec de la protéine." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S144/document.
Повний текст джерелаАнотація:
L'emploi des agents antibactériens est un moyen important d'une part dans la lutte contre les infections bactériennes et d'autre part pour conserver les produits alimentaires jusqu'à leur consommation. La perte d'efficacité des antibiotiques par le développement de résistance bactérienne ainsi que la toxicité des conservateurs synthétiques rend nécessaire le développement de nouveaux produits antibactériens naturels. Les protéines et les peptides antibactériens agissant sur les membranes bactériennes paraissent une alternative pour limiter l'instauration de résistances bactériennes. L'ovotransferrine est une protéine du blanc d'œuf ayant des propriétés membranotropes responsable entre autre de son activité antibactérienne. L'objectif de cette thèse est d'étudier les mécanismes membranotropes de l'ovotransferrine vis-à-vis des membranes externe et cytoplasmique d'E. coli en utilisant respectivement des monocouches de LPS (lipopolysaccharides) et de phospholipides comme modèles membranaires expérimentales. L'ovotransferrine possède une capacité d'insertion dans la monocouche de LPS qui dépend de la concentration protéique, de la compacité de la monocouche et de la conformation des molécules de LPS. L'ovotransferrine s'adsorbe faiblement à la monocouche de phospholipides. Ainsi, les monocouches sont perturbées par la désorganisation des lipides. L'analyse comparative de l'ovotransferrine chauffée à sec avec la forme native a montré la conservation des structures secondaire et tertiaire avec une augmentation de l'hydrophobie de surface et probablement de la flexibilité et une affinité plus élevée aux interfaces hydrophiles/hydrophobes (eau/air). L'activité membranaire de l'ovotransferrine est accrue après son chauffage à sec. La capacité d'insertion dans la monocouche de LPS est amplifiée avec une affinité plus importante. Une capacité d'insertion dans la monocouche de phospholipides est générée pour la forme chauffée à sec associée à une adsorption plus élevée. L'ovotransferrine chauffée à sec induit des perturbations plus importantes des monocouches à des concentrations protéiques plus faiblesThe use of antibacterial agents is very important, firstly, on the fight against bacterial infections, and secondly, to keep food products until its consumption. The loss of antibiotics effectiveness through the development of bacterial resistance and the toxicity of synthetic preservatives necessitates the development of new natural antibacterial products. Antibacterial proteins and peptides acting on the bacterial membranes appear as an alternative to limit the introduction of bacterial resistances. Ovotransferrin is an egg-white protein with membranotropic properties responsible among other things for its antibacterial activity. The aim of this thesis is to study the membranotropic mechanisms of ovotransferrin towards the outer and cytoplasmic membranes of E. coli using respectively monolayers of LPS (lipopolysaccharides) and phospholipids as experimental membrane models. Ovotransferrin has an insertion capacity in LPS monolayer that is dependent on protein concentration, monolayer compactness, and LPS molecule conformation. Ovotransferrin weakly adsorbs to the monolayer of phospholipids. Thus, the monolayers are disturbed by the disorganization of the lipids. Comparative analysis of dry-heated ovotransferrin with the native form showed conservation of secondary and tertiary structures with an increase of surface hydrophobicity and probably of flexibility and higher affinity to hydrophilic/hydrophobic interfaces (water/air). The insertion capacity in the LPS monolayer is amplified with greater affinity. Insertion capacity in the phospholipid monolayer is generated for the dry heated form associated with higher adsorption. Dry-heated ovotransferrin induces greater disruption of monolayers at lower protein concentrations
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Young, Christopher Michael. "Pressure Effects on Black Liquor Gasification." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11539.
Повний текст джерелаАнотація:
Gasification of black liquor is an alternative to the combustion of black liquor, which is currently the dominant form of chemical recovery in the paper industry. Gasification of black liquor offers the possibility of higher thermal efficiencies than combustion, reducing manufacturing costs and creating new revenue streams through a forest biorefinery. Pressurizing the gasification reactor further enhances the efficiency advantage of gasification over combustion.
This study uses a pressurized entrained flow reactor (PEFR) to study black liquor gasification behavior under pressures, temperatures, and heating rates similar to those of next-generation high-temperature black liquor gasifiers. The effects of pressure on black liquor char morphology, gasification rates, pyrolysis carbon yields, and sulfur phase distribution were studied. These characteristics were investigated in three main groups of experiments at 900oC: pyrolysis (100% N2), gasification with constant partial pressure (0.25 bar H2O and 0.50 bar CO2), and gasification with constant mole fraction (10% CO2, 2% H2O, 1.7% CO, 0.3% H2), under five, ten, and fifteen bar total pressure.
It was found that pressure had an impact on the char physical characteristics immediately after the char entered the reactor. Increasing pressure had the effect of decreasing the porosity of the chars. Pressure also affected particle destruction and reagglomeration mechanisms. Surface areas of gasification chars decreased with increasing pressures, but only at low carbon conversions.
The rate of carbon conversion in gasification was shown to be a function of the gas composition near the particle, with higher levels of inhibiting gases slowing carbon conversion. The same phenomenon of product gas inhibition observed in gasification was used to explain carbon conversions in pyrolysis reactions.
Sulfur distribution between condensed and gas phases was unaffected by increasing total pressure in the residence times investigated. Significant amounts of sulfur are lost during initial devolatilization. With water present this gas phase sulfur forms H2S and did not return to the condensed phase.
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Dombrosky, Robson Fernandes. "Eficientização de um sistema de climatização aeroportuário a partir do uso da termoacumulação." Universidade do Vale do Rio dos Sinos, 2012. http://www.repositorio.jesuita.org.br/handle/UNISINOS/4050.
Повний текст джерелаАнотація:
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Banco Santander / Banespa
O trabalho apresenta um estudo do sistema de climatização do aeroporto da cidade de Porto Alegre, visando determinar e mensurar as oportunidades de redução dos seus custos operacionais utilizando o tanque de termoacumulação já existente, recurso que por razões diversas encontra-se atualmente inoperante. Para possibilitar uma avaliação global do comportamento do sistema em estudo, tanto a edificação do terminal de passageiros quanto os equipamentos integrantes da sua planta de climatização foram modelados e simulados através do programa EnergyPlus, com uso de arquivo climático específico para a cidade de Porto Alegre. As simulações ratificaram as previsões de que o sistema de climatização do aeroporto de Porto Alegre trabalha atualmente com custos de operação superiores àqueles que poderiam ser obtidos caso o sistema de termoacumulação estivesse em operação. A economia integrada ao longo de um ano pela redução de custos com as faturas de energia do aeroporto atingiu R$ 312.206,00. Ficou evidente que a redução da demanda e consumo de energia em horário de ponta são as parcelas com maior representatividade na diminuição dos custos operacionais do sistema de climatização do aeroporto, respondendo, respectivamente, por 77% e 18% sobre todas as economias obtidas nas faturas de energia após o uso da termoacumulação. Constatouse que além da redução nos valores pagos pela utilização de energia elétrica em horário de ponta, a participação da termoacumulação possibilita também redução no consumo energético dos equipamentos da planta de climatização, motivada por estratégias de operação mais eficientes. Desta forma, considerando apenas os meses de verão, as simulações apontaram uma redução média de 11% no consumo referente aos equipamentos da planta de climatização. Se para o mesmo período forem também contabilizadas as economias devido redução de demanda e consumo em horário de ponta dos equipamentos de climatização, a redução total sobre a fatura de energia do aeroporto a partir do uso da termoacumulação situase em 30%. Outra importante questão relacionada ao uso da termoacumulação diz respeito à ampliação da capacidade frigorífica que a mesma proporciona ao sistema de climatização, efeito de elevada relevância para fazer frente ao aumento na movimentação de passageiros da aviação civil dos últimos anos. Nesse sentido, as simulações apontaram um incremento de cerca de 25% na capacidade de refrigeração da planta atual, após participação do tanque de termoacumulação. Tal efeito representa notória contribuição ao aumento da longevidade das instalações existentes, limitando ou eliminando a necessidade de maiores intervenções para aumento de capacidade de refrigeração da planta até o momento em que o terminal de passageiros venha a sofrer ampliações mais significativas.
The study presents the heating, ventilation and air conditioning system (HVAC) used in Porto Alegre city airport, aiming cost reductions opportunities due to its cool storage tank operation, a feature that for various reasons is currently out use. To enable a comprehensive assessment of the system’s behavior, both the passenger terminal building and HVAC equipment were modeled and simulated using the EnergyPlus software, along with the weather file that contains Porto Alegre’s meteorological data. The simulations have reaffirmed the predictions that Porto Alegre’s airport HVAC system is currently working with operating costs above those that could be obtained if the cool storage system were in operation. The integrated economy over a year by reducing costs to the electricity bills from the airport reached R$ 312.206,00. It became notorious that the reduction of demand and energy consumption during the peak hours are the most representative from all economies, accounting respectively for 77% and 18% of the total energy bills savings after cool storage tank operation. It was found that, besides the reduction in the amounts paid for electricity at peak hours, the participation of cool storage also enables reduction in energy consumption for HVAC plant equipments, driven by more efficient operating strategies. Thus, considering only the summer months, the simulations showed an average reduction of 11% in HVAC plant equipment consumption. As for the same period, if it is also accounted for the savings due to electric demand and consumption reduction during peak hours, the total energy bill reduction for the airport after applying the cool storage tank stands at 30%. Another important issue related to the use of cool storage is the HVAC cooling capacity increase, very relevant if considering the terminal passenger handling increase along last years. In that sense, the simulations showed a 25% increase in cooling capacity for the current system after the cool storage has joined the HVAC plant. This effect is a noticeable contribution to the existing installations longevity, as it limits or eliminates the need for further increase in the airport cooling capacity, not until the time when the passenger terminal may suffer significant enlargements.
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Novák, Jan. "Náhrada stávajícího zdroje vytápění průmyslového objektu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229764.
Повний текст джерелаАнотація:
The main aim of the thesis is to design a final draft for the reconstruction of the central heating plant of the industrial complex. The background research outlines a brief description of the development of heating plant industry, boilers and conditions for the selection of a suitable heat source for the particular area. Further, there are listed standard possibilities of heat sources for industrial complex, which does not use heat for technological purposes only, but as well as for heating and warming up of supply water. The finding and presentation section summarize the current energy supply and the design of two variants for conceptual modernization of the boiler plant. According to the annual and daily chart for the need for heat, there are specified required heat outputs, which are supposed to be distributed to the campus network of heating and as well as the fuel consumption. One of the options considers the use of storage tanks. The conclusion compares both suggested options.
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Gung-WuLai and 賴冠吾. "Development of Non-planar Induction Heating Coil for Rapid Mold Heating." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/98064863271939988588.
Повний текст джерелаАнотація:
碩士國立成功大學
機械工程學系碩博士班
100
Plastic products were the most common things we used in recent years, like daily necessities, 3C products and medical supplies, all of above things were injection molding products and wildly used in everyday. Injection molding in addition to satisfying the requirements of quality and precision density, it had more low-cost and high-volume characteristics, so it became an important technology of plastics processing. However, recent studies on induction heating applied to the mold mostly flat, in other word, heating coils would not have the level difference to each other. Actually injection molding products were non-planar, most of products had curve or difference depth. For these cases, if only use planar heating coil, it could not achieve good heating effect. This study was mainly designed non-planar heating coil, according to the depth of mold cavity designed heating coil in order to get high heating efficiency and high temperature uniformity. This study designed two heating coils. The first one total heating 10 seconds and temperature increased from 50oC to 74.27oC. Heating rate was 2.43oC/s and temperature uniformity was 77.66%. The second one total heating 10 seconds and temperature increased from 50oC to 81.14oC. heating rate was 3.11oC/s and temperature uniformity was 80.92%.
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Chu, Chao-Hsun, and 朱昭勳. "Investigation on Induction Heating Mold with Embedded Coil." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/mw6uu8.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
機電整合研究所
99
This mold is used for heating induction heating technology for research and development. To propose a high-frequency current through the induction coil induction heating embedded rapid increase in cavity surface temperature of the device method. Rapid heating by induction coil embedded mold temperature in plastic mold injection and continued heating phase, solution microstructure injection molding process flow due to a large shallow flow resistance caused by poor flow of plastic molding difficult. Use this technology to achieve rapid heating, control the heating temperature, etc., thus greatly shortening the production cycle, reduce production costs. In this study, using ANSYS simulation software embedded induction coil for the male and female mold mold heated situation, and use existing standard mold injection molding design and develop a set of specifications of the actual mold, and design a special coil connector with bakelite material of the body to fixed coil in the mold with the injection molding process clamping steps to verify the temperature experiments. From the design simulation results that the current size, the placement of the coil turns and the thickness of mold and mold temperature control and many other parameters, all affect the level of the mold cavity surface temperature and temperature distribution. Simulation results of this study show a good warming trend, micro-structure to meet the temperature requirements of injection molding, can indeed confirm that the embedded induction coil heating injection molds.
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Lin, Po-An, and 林柏安. "Investigation on Induction Heating Mold with Embedded Coil." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/68z9hb.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
機電整合研究所
97
This thesis researches the mold rapid heating with embedded coil by induction heating technique. Due to the poor flow capability of melting plastics into micro channel, it is difficult to inject the melted plastics into the cavities of the mold. In order to let the injection technique be used in the fabrication of microfluidic chip, raising cavity surface temperature will be one of the solutions. High mold temperature could improve the replication capacity of micro-structures, the problems of injection, the quality of products, and effectively reduces the cycle-time. Therefore, developing systems for rapidly heating and cooling for injection of microfluidic chip is the main objective of this study. We used CAE software-ANSYS to simulation the coil that heating the mold plate as compared with experiment. It is known the high permeability materials could make mold surface rapid heating by simulation and experiment. Coil current, coil to plate distance and frequency etc. could affect the mold surface temperature, too. The capability and accuracy of simulations on the induction heating are verified from experiments, the simulated temperature distributions show reasonable agreement with measured results. We can do complex coil design and use ANSYS software to analysis. To evaluate the feasibility and efficiency of induction heating on the mold surface temperature control.
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Singh, Gurinder. "Adaptive control of a multizone fan-coil heating system." Thesis, 1993. http://spectrum.library.concordia.ca/4769/1/MM90890.pdf.
Повний текст джерела
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Cheng, Shin-Lung, and 鄭馨隆. "Integration System of Mold Embedded with Induction Heating Coil." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/mr28nt.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
機電整合研究所
102
My research and development is to aim for mold heating induction heating technology. There two ways of propose with passing a high-frequency current through the induction coil and embedded integrated with concentrator method for rapidly increased the surface temperature of the mold cavity. Mold temperature of this technology through rapid heating is induction coil embedded in the plastic injection mold to be heated up, this phenomenon solving injection molding process flow resistance caused by poor liquidity of plastic molding difficulties. That the importance of the technology of rapid heating mold temperature will reduce production costs in order to achieve objectives while taking into account for shorten molding cycle and high production rates. This paper using ANSYS APDL / ANSYS Maxwell for comparison and mainly used ANSYS Multiphysics simulation software to simulate embedded induction heating coil and oil heating to make a comparison of increasing mold temperature. ANSYS used in mold temperature field analysis and verification do discuss and theory , the coupling of electromagnetic and thermal analysis is applied to the induction coil design is analyzed for induction heating simulations to find relevant operating parameters and verify the credibility of the analysis to determine the feasibility of heating source mold temperature field analysis with ANSYS software . In this study, the use of existing standard injection molding mold design and development of a set of specifications of the actual mold with designing a special coil and institutional fixed coil phenolic material in the injection molding process with the heating and cooling steps to simulate and analyze the mold.
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LI, WEI-SHAN, and 李維善. "Numerical Analysis of Solar Thermal Heating Regular Polygonal Coil Heat Exchanger." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/e854f5.
Повний текст джерелаАнотація:
碩士和春技術學院
電機工程研究所
107
In this study, COMSOL 5.1 analysis software was used to simulate the different heat transfer effects produced by solar radiation heating of polygonal coil heat exchangers, and the better design and size parameters were analyzed and compared. The heat transfer heat of the heat transfer oil was set at 373.15K, 473.15K, 573.15K and 673.15K, and the cold fluid was 298.15 K pure water. The results show that the maximum outlet temperature of the heated pure water medium is 343.65K, 404.38K, 465.21K and 525.95K when the number of coils is 7 sided, the cold fluid temperature difference is 45.5K, 106.23K, 173.25K and 227.8K respectively. As a result of numerical verification, this study is the configuration of polygonal coil heat exchangers, which is superior to the heat transfer efficiency of circular spiral coil heat exchangers. Keywords：concentrated solar power, polygonal coil, heat exchanger, heat transfer efficiency.
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Huang, Yao-Lin, and 黃耀霖. "The Induction Coil Design Applied for Rapid Surface Heating of Injection Molding." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/549rys.
Повний текст джерелаАнотація:
碩士國立高雄第一科技大學
機械與自動化工程所
96
The study aims to investigate the optimized designation of high-frequency electromagnetic induction coils, which are utilized in the rapid mold surface heating of injection mold, in order to realize rapid heating, uniform temperature distribution, and maximized heated area at even temperature. The study is mainly concerned with solving the unbalanced heat distribution of heated target at its cross and deep sections due to the approximate and skin effects most commonly occurring at the use of conventional single layer coil for induction heating. By adopting an injection mold plate the carrier of simulation and experiment, this work first employs the multiple physics coupling analysis technique simulated in the ANSYS software to predict the induction heating temperature profile. Integration of Taguchi method and principal component analysis (PCA) are then developed to search for the optimal design of induction coil and process parameters. The coil layer after optimization is further explored its effect on heating history. Lastly, the optimized induction coil and conventional single layer coil are compared with heating time required to reach 100℃ surface temperature and the maximal heated area at even temperature, defined as 5℃ variation. The experimental results that: (1) the optimized coil requires only 3 seconds to reach uniform temperature distribution and the working temperature raise to 190.1℃, as the conventional single layer coil is 168.3℃ and unable to reach balanced temperature after 11 seconds. (2) For repeatability testing of induction heating to 190℃ with optimized coil, the temperature variation is less then 5℃. (4) The power consumption of the optimized coil is 14.8% less than the conventional one.