Inhaltsverzeichnis
Auswahl der wissenschaftlichen Literatur zum Thema „Heat output from the switchgear“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit den Listen der aktuellen Artikel, Bücher, Dissertationen, Berichten und anderer wissenschaftlichen Quellen zum Thema "Heat output from the switchgear" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Zeitschriftenartikel zum Thema "Heat output from the switchgear"
1
Yu, Hong, Maoyong Cao, Tanbo Zhu, and Fanming Liu. "Study of Heating Device for Sulfur Hexafluoride Gasification." Sensor Letters 18, no. 2 (2020): 157–63. http://dx.doi.org/10.1166/sl.2020.4201.
Der volle Inhalt der QuelleAnnotation:
Sulfur hexafluoride (SF6) gas has been used to gas-insulated switchgear (GIS) because of its insulation properties and extinguishing characteristics. The processing of liquid sulfur hexafluoride from cylinders into GIS is endothermic. The processing gas inflation always leads to decrease SF6 gas inflation speed due to the lack of heat supplement and the infiltrated moisture will stick on the GIS equipment, especially at the valve outlet. In the paper, a heater detection device for sulfur hexafluoride (SF6) steel cylinder is developed. The new heater device will monitor and display the specific temperature and humidity of the valve outlet instantaneously and then heat and dry the sulfur hexafluoride (SF6) steel cylinder with automatic and stability. Then it helps to speed up the sulfur hexafluoride gasification. Meanwhile, the whole device is portable in safety.
2
Erickson, Donald C., Gopalakrishnan Anand, and Ellen Makar. "Absorption Refrigeration Cycle Turbine Inlet Conditioning." International Journal of Air-Conditioning and Refrigeration 23, no. 01 (2015): 1550003. http://dx.doi.org/10.1142/s2010132515500030.
Der volle Inhalt der QuelleAnnotation:
Ambient temperature markedly impacts combustion turbine performance. A typical aeroderivative turbine loses 25% of ISO capacity at 38°C ambient. There are two traditional options to mitigate that degradation: evaporative cooling and mechanical chilling. They boost turbine performance, but consume significant water and/or electric load. Also, the turbine requires separate anti-icing equipment for low ambient temperature operation (less than 4.4°C). This paper describes the Absorption Refrigeration Cycle Turbine Inlet Conditioning (ARCTIC) system that chills or heats the inlet air of a combustion turbine to maintain maximum turbine performance at all ambient temperatures. The ARCTIC unit is an ammonia–water absorption cycle that is powered by turbine exhaust heat. The design and performance of a 7034 kW (2000-ton) ARCTIC unit is presented. This ARCTIC achieved a new record for net power and heat rate from this model aeroderivative gas turbine in hot weather. It provides reliable and dispatchable hot day power at about half the cost of new plant. On a typical summer day (38°C dry bulb, 26°C wet bulb), ammonia refrigerant from the ARCTIC chills the inlet air to 8.9°C. The gas turbine power is increased from 40 to 51 MW. After allowing for the 230 kW electric parasitic load, the resulting net power is 2 MW more than the output of a comparable mechanically chilled gas turbine. As a result, the heat rate is also improved. On cold days the ARCTIC automatically switches to heating mode. The inlet air is heated by 11°C to eliminate inlet icing potential. Additional benefits include a lower exhaust temperature which is better for the Selective Catalytic Reduction (SCR) catalyst. The condensate recovered from the inlet-air chilling (up to 25 gallons per minute) can also be a valuable by-product. The ARCTIC system has a small cost premium relative to a mechanical chiller. However, when all the auxiliary functions are credited (anti-icing, tempering air, less switchgear, no 4160 volt service), the overall installed cost is comparable. The standout advantages are the increased hot weather power output, improved operating efficiency, and reduced maintenance, all obtained at minimal additional cost. Combined cycle and cogeneration configurations (both frame and aeroderivative) benefit even more from the ARCTIC due to the increased value of improved heat rate.
3
Gao, Bao-Ming, Zheng-Yu Li, Jin-Wen Gao, Hao Liang, Zhi Yan, and Yi-Dan Hu. "The Simulation Study on Temperature Field Distribution of 220 kV Gas Insulated Switchgear." Journal of Nanoelectronics and Optoelectronics 16, no. 5 (2021): 797–805. http://dx.doi.org/10.1166/jno.2021.2998.
Der volle Inhalt der QuelleAnnotation:
Under working conditions, the conductive rods in the GIS flow through the power frequency alternating current. Due to the coupling effect of the magnetic field and electric field between the metal aluminum shell and the conductive rod, induced eddy currents are generated in the metal shell of the GIS. The heat generated by the current heating effect of the GIS conductive rod and the eddy current loss of the metal casing will cause the temperature rise of GIS equipment. Due to the limited volume, the heat dissipation capacity of GIS is poor. Excessive temperature rise will accelerate the insulation aging of GIS equipment, and even damage its insulation, which will affect safe operation. In order to obtain the temperature change law of GIS, related influencing factors such as eddy current loss, skin effect, proximity effect, convective heat transfer of SF6 gas, and gravity of SF6 gas are comprehensively considered. The finite element analysis is used to research and discuss GIS magnetic field distribution, eddy current, temperature distribution and SF6 gas velocity. The initial value of the temperature of each part is set to 293.15 K (20 °C), and the temperature in the GIS is calculated to gradually decrease from the inside to the outside under the rated AC current of 3150 A. The temperature at the conductive rod position is the highest at 335.32 K, and the temperature at the housing position is the lowest at 294.65 K.
4
Kapjor, Andrej, Peter Durcansky, and Martin Vantuch. "Effect of Heat Source Placement on Natural Convection from Cylindrical Surfaces." Energies 13, no. 17 (2020): 4334. http://dx.doi.org/10.3390/en13174334.
Der volle Inhalt der QuelleAnnotation:
Placement of heat source can play a significant role in final heat output, or heat source effectivity. Because of this, there is a need to analyze thermal fields of the heat exchange system by natural convection, where the description by criterion equations is desired, as the net heat output from tubes can be quantified. Based on known theoretical models, numerical methods were adapted to calculate the heat output with natural air flow around tubes, where mathematical models were used to describe the heat transfer more precisely. After validation of heat transfer coefficients, the effect of wall and heat source placement was studied, and the Coanda effect was also observed. The heat source placement also has an effect at the boundary layer, which can change and therefore affect the overall heat transfer process. The optimal wall-to-cylinder distance for an array of horizontal cylinders near a wall was also expressed as a function of the Rayleigh number and number of cylinders in the array.
5
Wu, Bisheng, Tianshou Ma, Guanhong Feng, Zuorong Chen, and Xi Zhang. "An Approximate Solution for Predicting the Heat Extraction and Preventing Heat Loss from a Closed-Loop Geothermal Reservoir." Geofluids 2017 (2017): 1–17. http://dx.doi.org/10.1155/2017/2041072.
Der volle Inhalt der QuelleAnnotation:
Approximate solutions are found for a mathematical model developed to predict the heat extraction from a closed-loop geothermal system which consists of two vertical wells (one for injection and the other for production) and one horizontal well which connects the two vertical wells. Based on the feature of slow heat conduction in rock formation, the fluid flow in the well is divided into three stages, that is, in the injection, horizontal, and production wells. The output temperature of each stage is regarded as the input of the next stage. The results from the present model are compared with those obtained from numerical simulator TOUGH2 and show first-order agreement with a temperature difference less than 4°C for the case where the fluid circulated for 2.74 years. In the end, a parametric study shows that (1) the injection rate plays dominant role in affecting the output performance, (2) higher injection temperature produces larger output temperature but decreases the total heat extracted given a specific time, (3) the output performance of geothermal reservoir is insensitive to fluid viscosity, and (4) there exists a critical point that indicates if the fluid releases heat into or absorbs heat from the surrounding formation.
6
Dear, Keith. "Modelling Productivity Loss from Heat Stress." Atmosphere 9, no. 7 (2018): 286. http://dx.doi.org/10.3390/atmos9070286.
Der volle Inhalt der QuelleAnnotation:
Workers exposed to high ambient temperatures, either indoors or out, work slower. The few studies that have measured this loss of productivity show a degree of consistency across widely varying settings. I develop a class of 5-parameter probability models that express productivity as a function of environmental heat and show how the method of fitting can be adapted according to the completeness of the data available. As well as modelling the mean output, it is important to also consider variation between workers, and the model presented here achieves this. The method is illustrated using three previously published datasets from different industries and work environments.
7
Shibasaki, Manabu, Thad E. Wilson, Morten Bundgaard-Nielsen, Thomas Seifert, Niels H. Secher, and Craig G. Crandall. "Modelflow underestimates cardiac output in heat-stressed individuals." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 300, no. 2 (2011): R486—R491. http://dx.doi.org/10.1152/ajpregu.00505.2010.
Der volle Inhalt der QuelleAnnotation:
An estimation of cardiac output can be obtained from arterial pressure waveforms using the Modelflow method. However, whether the assumptions associated with Modelflow calculations are accurate during whole body heating is unknown. This project tested the hypothesis that cardiac output obtained via Modelflow accurately tracks thermodilution-derived cardiac outputs during whole body heat stress. Acute changes of cardiac output were accomplished via lower-body negative pressure (LBNP) during normothermic and heat-stressed conditions. In nine healthy normotensive subjects, arterial pressure was measured via brachial artery cannulation and the volume-clamp method of the Finometer. Cardiac output was estimated from both pressure waveforms using the Modeflow method. In normothermic conditions, cardiac outputs estimated via Modelflow (arterial cannulation: 6.1 ± 1.0 l/min; Finometer 6.3 ± 1.3 l/min) were similar with cardiac outputs measured by thermodilution (6.4 ± 0.8 l/min). The subsequent reduction in cardiac output during LBNP was also similar among these methods. Whole body heat stress elevated internal temperature from 36.6 ± 0.3 to 37.8 ± 0.4°C and increased cardiac output from 6.4 ± 0.8 to 10.9 ± 2.0 l/min when evaluated with thermodilution ( P < 0.001). However, the increase in cardiac output estimated from the Modelflow method for both arterial cannulation (2.3 ± 1.1 l/min) and Finometer (1.5 ± 1.2 l/min) was attenuated compared with thermodilution (4.5 ± 1.4 l/min, both P < 0.01). Finally, the reduction in cardiac output during LBNP while heat stressed was significantly attenuated for both Modelflow methods (cannulation: −1.8 ± 1.2 l/min, Finometer: −1.5 ± 0.9 l/min) compared with thermodilution (−3.8 ± 1.19 l/min). These results demonstrate that the Modelflow method, regardless of Finometer or direct arterial waveforms, underestimates cardiac output during heat stress and during subsequent reductions in cardiac output via LBNP.
8
Orlov, Vladimir N., and R. Stephen Berry. "Power output from an irreversible heat engine with a nonuniform working fluid." Physical Review A 42, no. 12 (1990): 7230–35. http://dx.doi.org/10.1103/physreva.42.7230.
Der volle Inhalt der Quelle
9
Elghool, Ali, Firdaus Basrawi, Hassan Ibrahim, Thamir K. Ibrahim, Shaharin A. Sulaiman, and M. Ishak. "Study on the Performance of a Thermo-Electric Generation Model with Two Different Materials of Heat Pipe-Heat Sink." MATEC Web of Conferences 225 (2018): 04009. http://dx.doi.org/10.1051/matecconf/201822504009.
Der volle Inhalt der QuelleAnnotation:
Heat sink lack of design is one reason that negatively affects the performance of thermoelectric modules. As compared to conventional cooling systems equipped with thermoelectric generators (TEG), heat pipe heat sink has various points of interest. Heat pipe heat sink is the most appropriate heat exchanger for medium temperature range under 300 °C. This paper demonstrates the effect of different materials of heat pipe-heat sink on the TEG performance. Two types of heat sinks were tested with TEG, one made from copper while the other from aluminium. The aim is to improve power output of TEG by an appropriate material of fins and metal block with heat pipes. The prototype was experimentally tested and the TEG cold side temperature, voltage and current were measured in both conditions, natural and forced convection. It was found that highest power output was achieved using copper heat sink in the case of forced convection, being 7.7 W whereas, lowest power output was obtained using aluminium heat sink in the case of natural convection, being 2.67 W. It is evident that copper heat sink is more effective than aluminium heat sink in terms of power output. However, both types of heat sink needs optimisation in terms of power output, cost and economic efficiency, while the results shown in this paper are just in terms of power output.
10
Guyomar, Daniel, Gaël Sebald, Sébastien Pruvost, Mickaël Lallart, Akram Khodayari, and Claude Richard. "Energy Harvesting from Ambient Vibrations and Heat." Journal of Intelligent Material Systems and Structures 20, no. 5 (2008): 609–24. http://dx.doi.org/10.1177/1045389x08096888.
Der volle Inhalt der QuelleAnnotation:
Increasing demand in mobile, autonomous devices has made the issue of energy harvesting a particular point of interest. Systems that can be powered up by a few hundreds of microwatts can feature their own energy extraction module, making them truly self-powered. This energy can be harvested from the close environment of the device. Particularly, piezoelectric conversion is one of the most investigated fields for ambient energy harvesting. Moreover, the extraction process can be optimized by proper treatment of the piezomaterial output voltage. This article proposes a detailed explanation of the real energy flow that lies behind several energy conversion techniques for piezoelectric energy scavenging. As well, the principles of energy harvesting using piezoelectric effect is extended to the pyroelectric effect, therefore allowing harvesting energy from temperature variation, which is one of the most common energy sources.
Dissertationen zum Thema "Heat output from the switchgear"
1
Rusetskyi, Ivan. "Vzduchem chlazený rozvaděč." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443249.
Der volle Inhalt der QuelleAnnotation:
During the operation of electrical equipment, heat is generated due to internal losses of the equipment. If these devices are located in the switchgear, the heat output of the individual elements adds up and the temperature in the switchboard can rise to values when the reliability of the individual devices decreases. One of the ways to prevent increase the temperature inside the switchgear from rising to critical values is to solve its proper ventilation (cooling with ambient air). By natural convection or using a ventilator. This diploma thesis deals with the most reliable way of cooling UniGear ZS1 switcgears by natural convection.
2
Liu, Lei. "Heat transfer from a convecting crystallizing, replenished magmatic sill and its link to seafloor hydrothermal heat output." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37215.
Der volle Inhalt der QuelleAnnotation:
Hydrothermal systems at oceanic spreading centers play an important role in the composition of seawater, the formation of ore deposits, the support of microbial and macrofaunal ecosystems, and even for the development of life on early earth. These circulation systems are driven by heat transport from the underlying magma chamber, where latent heat of crystallization and sensible heat from cooling are transferred by vigorous, high Rayleigh number convection through a thin conductive boundary layer.
The traditional study of magmatic-hydrothermal systems is primarily based on the time-series observation, which takes the form of repeat visits, continuous offline monitoring by autonomous instruments, or continuous online monitoring by instruments with satellite or cable links to shore. Although a number of studies have deployed autonomous monitoring instruments at vents and around mid-ocean ridges to investigate geophysical and hydrothermal processes, the data are still rather limited and a comprehensive understanding of magma-hydrothermal processes at oceanic spreading centers is lacking. Numerical modeling needs to be employed to elucidate the dynamic behavior of magmatic hydrothermal systems and for testing completing hypotheses in these complex, data-poor environments.
In this dissertation, I develop a mathematical framework for investigating heat transport from a vigorously convecting, crystallizing, cooling, and replenished magma chamber to an overlying hydrothermal system at an oceanic spreading center. The resulting equations are solved numerically using MATLAB. The simulations proceed step-by-step to investigate several different aspects of the system.
First, I consider a hydrothermal system driven by convection, cooling and crystallization in a ~ 100 m thick basaltic magma sill representing an axial magma chamber (AMC) at an oceanic spreading center. I investigate two different crystallization scenarios, crystal-suspended and crystal-settling, and consider both un-replenished and replenished AMCs. In cases without magma replenishment, the simulation results for crystals-suspended models show that heat output and the hydrothermal temperature decrease rapidly and crystallinity reaches 60% in less than ten years. In crystals-settling models, magma convection may last for decades, but decreasing heat output and hydrothermal temperatures still occur on decadal timescales. When magma replenishment is included, the magmatic heat flux approaches steady state on decadal timescales, while the magma body grows to double its original size. The rate of magma replenishment needed ranges between 5 x 10⁵ and 5 x 10⁶ m³/yr, which is somewhat faster than required for seafloor spreading, but less than fluxes to some terrestrial and subseafloor volcanoes on similar timescales. The heat output from a convecting, crystallizing, replenished magma body that is needed to drive observed high-temperature hydrothermal systems is consistent, with gabbro glacier models of crustal production at mid-ocean ridges.
Secondly, I study the heat transfer model from a parametric perspective and examine the effects of both initial magma chamber thickness and magma replenishment rate on the hydrothermal heat output. The initial rate of convective heat transfer is independent of the initial sill thickness; but without magma replenishment, the rate of decay of the heat output varies linearly with thickness, resulting in short convective lifetimes and decaying hydrothermal temperatures for sills up to ~ 100m thick. When magma replenishment is included in crystals settling scenarios at constant or exponentially decreasing rates of ~ 10⁻⁸ m/s to the base of the sill, growth of the sill results in stabilized heat output and hydrothermal temperature on decadal timescales and a relatively constant to increasing thickness of the liquid layer. Sills initially ~ 10 m thick can grow, in principal, to ~ 10 times their initial size with stable heat output and a final melt thickness less than 100m. Seismic data provides evidence of AMC thickness, but it can not discriminate whether it denotes initial magma thickness or is a result of replenishment. These results suggest that magma replenishment might not be seismically detectable on decadal time scales. Periodic replenishment may also result in quasi-stable heat output, but the magnitude of the heat output may vary considerably in crystals suspended models at low frequencies; compared to crystals settling models. In these models the direct coupling between magmatic and hydrothermal heat output suggests that heat output fluctuations might be recorded in hydrothermal vents; but if damping effects of the basal conductive boundary layer and the upflow zone are taken into account, it seems unlikely that heat output fluctuations on a time scale of years would be recorded in hydrothermal vent temperatures or heat output.
Thirdly, I extend the work to the binary system motivated by the fact that the real magmas are multi-component fluids. I focus on the extensively studied binary system, diopside-anorthite (Di-An), and investigate the effects of convection of a two-component magma system on the hydrothermal circulation system through the dynamic modeling of both temperature and heat output. I model the melt temperature and viscosity as a function of Di concentration, and incorporate these relations in the modeling of the heat flux. Simulations comparing the effects of different initial Di concentrations indicate that magmas with higher initial Di concentrations convect more vigorously, which results in faster heat transfer, more rapid removal of Di from the melt and growth of crystals on the floor. With magma replenishment, I assume that the magma chamber grows either horizontally or vertically. In either case magma replenishment at a constant rate of ~ 10⁻⁸ m³/a can maintain relatively stable heat output of 10⁷-10⁹ Watts and reasonable hydrothermal vent temperatures for decades. The final stabilized heat flux increases with increasing Di content of the added magma. Periodic replenishment with a 10 year period results in temperature perturbations within the magma that also increase as a function of increasing Di. With the simple magma model used here, one can not discern conclusively whether the decrease in magma temperature between the 1991/1992 and the 2005/2006 eruptions at EPR 9°50'N involved replenishment with more or less evolved magmas.
Fourthly, I investigate a high-silica magma chamber as the hydrothermal circulation driver. I construct viscosity models for andesite and dacite melts as a function of temperature and water content and incorporate these expressions into a numerical model of thermal convective heat transport from a high Rayleigh number, well-mixed, crystallizing and replenished magma sill beneath a hydrothermal circulation system. Simulations comparing the time dependent heat flux from basalt, 0.1wt.% andesite, 3wt.% andesite, and 4wt.% dacite, indicate that higher viscosity magmas convect less vigorously, which results not only in lower heat transport and hydrothermal vent temperatures, but also in a lower decay rate of the vent temperature. Though somewhat colder, hydrothermal systems driven by unreplenished high-silica melts tend to have a longer lifetime than those driven by basalts, assuming a heat output cutoff of 10⁷ Watts. As in the basaltic case, magma replenishment at a rate of ~ 3 x 10⁵ - 3 x 10⁶ m³/a can maintain relatively stable heat output of 10⁷-10⁹ Watts and hydrothermal vent temperatures for decades. Idealized models of porous flow through the lower crust suggest such replenishment rates are not likely to occur, especially for high-viscosity magmas such as andesite and dacite. Long term stability of hydrothermal systems driven by these magmas requires an alternate means of magma replenishment.
Finally, the dissertation concludes by discussing some avenues for future work. Most important of these are to: (1) couple magma convection with more realistic hydrothermal models and (2) link magma chamber processes to better physical models of replenishment and eruption.
Bücher zum Thema "Heat output from the switchgear"
1
Wilton, Niall, Brian J. Anderson, and Bruno Marciniak. Anatomy, physiology, and pharmacology in paediatric anaesthesia. Edited by Jonathan G. Hardman and Neil S. Morton. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199642045.003.0069.
Der volle Inhalt der QuelleAnnotation:
Anaesthesia for children is tempered by changes that occur during both growth and development. Drug dose is affected by size and clearance maturation processes as well as the changing body composition that occurs with age. All organ systems undergo these maturation changes and most are complete within the first few years of life. Normal physiological variables in infancy and childhood are quite different from adults. The central nervous, cardiovascular, and respiratory systems are particularly important. Cerebral immaturity and plasticity impacts sensitivity to drugs, pain responses, and behaviour and increases potential harm from apoptosis with anaesthesia. The heart undergoes a transition from fetal to adult circulation during the first few weeks of life. Undiagnosed congenital defects are not uncommon. The neonate is very susceptible to conditions that trigger an increase in pulmonary vascular resistance, with reversion to fetal circulatory patterns. Respiratory anatomy and mechanics affect the propensity to apnoea, airway maintenance, artificial ventilation modalities, uptake of inhalational agents, and tracheal tube sizes. Metabolic rate and oxygen requirements increase with decreasing age. This physiology influences diverse aspects that include the rate of desaturation during apnoea, hypoglycaemia during starvation, cardiac output, drug metabolism, fluid requirements, and heat production or loss.
2
Mehta-Bhatt, Purvi, and Pier Paolo Ficarelli. Livestock in the Food Debate. Edited by Ronald J. Herring. Oxford University Press, 2014. http://dx.doi.org/10.1093/oxfordhb/9780195397772.013.024.
Der volle Inhalt der QuelleAnnotation:
Livestock is an integral part of agriculture and a prominent source of food. It contributes 40% of the global value of agricultural output and supports the livelihoods and food security of almost a billion people, especially in developing countries. There is nothing new in amalgamation of farm animals in agriculture system, but the debate questioning its existence and relevance is a rather new drift. The politics, the climate debate, the nutrition debate around livestock sector, especially levitating from industrial countries, needs to be sympathetic toward the millions of people, especially in developing countries, that continue to remain dependent on livestock as an important, or often the only, source of livelihood. This chapter looks at the diverse livestock agriculture systems in industrial and less developed countries and it’s policy implications. It re-examines the prevailing debates such as, the heat and meat debate, the zoonotic disease discussions, the debate on ethics around animal-source food and the debate of over- and undernutrition. The authors take a balanced view on the pros and cons of livestock sector, considering the global debates, but at the same time, looking at livestock sector’s socioeconomic and nutrition value for the poor. Take a global view, debate, campaign but don’t forget to also look at the sector from livelihood and food-security angle. The underline message of the chapter is to call for a bounteous outlook, evidence-based debate and equable policies.
Buchteile zum Thema "Heat output from the switchgear"
1
Ahmad Jamil, Muhammad, Talha S. Goraya, Haseeb Yaqoob, Kim Choon Ng, Muhammad Wakil Shahzad, and Syed M. Zubair. "Exergoeconomic and Normalized Sensitivity Analysis of Plate Heat Exchangers: A Theoretical Framework with Application." In Heat Exchangers [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99736.
Der volle Inhalt der QuelleAnnotation:
Heat exchangers are the mainstay of thermal systems and have been extensively used in desalination systems, heating, cooling units, power plants, and energy recovery systems. This chapter demonstrates a robust theoretical framework for heat exchangers investigation based on two advanced tools, i.e., exergoeconomic analysis and Normalized Sensitivity Analysis. The former is applied as a mutual application of economic and thermodynamic analyses, which is much more impactful than the conventional thermodynamic and economic analyses. This is because it allows the investigation of combinatory effects of thermodynamic and fiscal parameters which are not achieved with the conventional methods. Similarly, the Normalized Sensitivity Analysis allows a one-on-one comparison of the sensitivity of output parameters to the input parameters with entirely different magnitudes on a common platform. This rationale comparison is obtained by normalizing the sensitivity coefficients by their nominal values, which is not possible with the conventional sensitivity analyses. An experimentally validated example of a plate heat exchanger is used to demonstrate the application of the proposed framework from a desalination system.
2
B, Muthuraj, Sundramoorthi S, Vasudevan V, Jessica Angelyn J, and Raveena R. "Energy Scavenging from Triaxial Tactile Sensing and Peltier Effect Sensing System." In Intelligent Systems and Computer Technology. IOS Press, 2020. http://dx.doi.org/10.3233/apc200128.
Der volle Inhalt der QuelleAnnotation:
In the recent past there has been a significant increase in the research on vibration-based energy harvesting. Wherever mechanical movement exists, a lot of heat and vibration energy is wasted which could be used and converted as a supplement to the energy requirements. Towards this objective this project aims to provide a general theory that can be used for generating electricity from vibrating as well as heat body and store the acquired energy using advanced component called the super capacitor. A combination of Cantilever beam and MMA sensor is used for the sensing vibratory motion and the Peltier sensor is used for sensing the temperature of the source. The output obtained from the former source is converted into voltage using MMA technology and the latter is converted directly into the same. Boosted voltage is stored effectively with the help of super capacitor in primary storage device. The acquired voltage from the battery is 12V with respect to this project. For the AC load, the current produced are 300mA. The output would change with respect to the vibrating and the temperature sources like generators or automotive engines
3
Bai, Attila, and Zoltán Gabnai. "Opportunities of Circular Economy in a Complex System of Woody Biomass and Municipal Sewage Plants." In Forest Biomass - From Trees to Energy. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.93474.
Der volle Inhalt der QuelleAnnotation:
In this chapter, we present the opportunities and general importance of woody biomass production (forests and short-rotation coppices) and waste management in a common system. Wastewater and different forms of sewage sludge, as energy- and nutrient-rich materials, can contribute to reaching resource efficiency, savings in energy, and reduction of CO2 emissions. Within certain limits, these woody plantations are suitable options for the environmentally sound disposal of wastewater and/or sewage sludge; in addition, they can facilitate the realization of full or partial energy self-sufficiency of the wastewater plant through bioenergy production. Focusing on circular economy, we introduce the aspects of the treatment process and the sizing issues regarding the municipal wastewater treatment and the woody biomass in a complex system. Based on a specific case study, approximately 826 ha of short-rotation coppices (with a 2-year rotation) are required for the disposal of sewage sludge generated by a 250,000 population equivalent wastewater treatment plant. If we look at the self-sufficiency of its energy output, 120–150 ha of short-rotation coppices may be adequate. This complex system can replace the emissions of around 5650 t of CO2 through electricity generation alone and another 1490 t of CO2 by utilizing the waste heat.
4
"Independent Microgrid Composed of Distributed Engine Generator." In Advances in Environmental Engineering and Green Technologies. IGI Global, 2014. http://dx.doi.org/10.4018/978-1-4666-5796-0.ch007.
Der volle Inhalt der QuelleAnnotation:
This chapter consists of two sections, ‘Energy Cost of an Independent Microgrid with Control of Power Output Sharing of a Distributed Engine Generator’ and ‘Improvement of Power Generation Efficiency of an Independent Microgrid Composed of Distributed Engine Generators’. In the 1st section, small kerosene diesel-engine power generators are introduced into an independent microgrid, and power and heat are supplied to 20 houses. If the proposed system is introduced into a community with little heat demand, effectiveness will decrease greatly. The 2nd section investigates the power generation efficiency and power cost of an independent microgrid that distributes the power from a small diesel engine power generator. When the number of distributions of the engine generator is installed, the cost of the fuel decreases.
5
Kenneth Chima, Orgu, Chukwu Andy Onyema, Onubuogu Gilbert Chinedu, and Esiobu Nnaemeka Success. "Does Rural Livestock Farmers’ Have Knowledge of Organic Livestock Farming Practices? Lesson from Southeast, Nigeria." In Agricultural Economics [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99961.
Der volle Inhalt der QuelleAnnotation:
At global level, the use of inorganic feeds, veterinary drugs amongst others can significantly increase farm output in various livestock production systems. However, in recent times, quality-conscious consumers are increasingly seeking environmentally safe and chemical-residue free healthy livestock foods which organic production methods are said to ensure. Livestock Organic farming can offer promising opportunities for ensuring safe food, environmental sustainability, high livestock yield and income. Incidentally, empirical evidence on present discourse is still relatively very little. Although, a significant contribution has been made by various scholars, regrettably, these studies did not dwell on organic livestock practices and their knowledge level in South-east, Nigeria. Therefore, this presents a dearth in research and became increasingly pertinent that the study was systematically undertaken. A multistage and purposive random sampling procedure was used in the selection of 504 respondents who are organic livestock farmers. Data collected was analyzed using mean score analysis. Result shows that farmers had knowledge on practices of extensive system of livestock/poultry farming (X̄=3.49); provision of natural air (X̄=3.50); provision of natural water sprinkling during hot weather (X̄=3.50); rearing animal without antibiotics (X̄=3.56); and treating injured animals organically (X̄=3.48) among others. Incidentally, majority of the livestock farmers lacked knowledge of how to induce ovulation for animals without drugs (X̄=1.88). The inducement of ovulation for farm animals is one of the livestock organic methods used in forcing farm animals to come on heat/ovulation for quick multiplication. This method is harmful both for the animal an eventual consumer. Therefore, it is necessary that extension agents who are subject matter specialist (SMS) in livestock organic farming educate farmers on how to induce ovulation to farm animals organically with support from the government and farmers cooperative membership resources as these would significantly reduce harmful drugs injected to animal for quick ovulation and preserve the life span of the animal and consumers of the animal.
6
Gutschick, Vincent P., and Keirith A. Snyder. "Water and Energy Balances within the Jornada Basin." In Structure and Function of a Chihuahuan Desert Ecosystem. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195117769.003.0012.
Der volle Inhalt der QuelleAnnotation:
This chapter describes general characteristics and components of the energy and water balances in arid regions, with specific examples from the Jornada Basin. Various research efforts to characterize the energy and water balances and resultant carbon dioxide fluxes in the Jornada Basin are detailed. We provide a brief overview of how plant physiology interacts with energy and water balances in this region, and characterize general abiotic conditions and some physiological traits of plants in this arid region. The surface of a landscape may be considered as a layer with some amount of vegetation. More general descriptions divide the vegetation, like the soil, into layers, but the concern here is energy balance at the interface with the atmosphere. The net energy balance of the land surface is determined by inputs (radiant energy), outputs (reflection [i.e., albedo], emission of longwave radiation, convective heat transfer to the atmosphere [i.e., sensible heat flux], evapotranspiration of water [i.e., latent heat flux], and conduction of heat into soil), and changes in heat storage. The balance of these terms is adjusted as the surface temperature comes into steady state or nearly so. Increased solar input will drive surface temperatures higher until longwave emission and other losses come into a new balance. The net energy input, as inputs minus outputs, may be stated formally as an energy-balance equation . . . Rate of heat storage = S = Q+sw + Q+TIR − Q+TIR _ Q_E Q_H − Q_S, (8-1) . . . where the superscript + indicates an input, and − indicates an output or loss, and all terms are expressed as flux density in units of W/m2. Q+SW is the energy added to the surface layer by solar radiation from above. Q+TIR is the thermal infrared radiation emitted by gases in the atmosphere, principally water vapor and CO2, whereas Q_TIR is the thermal infrared radiation emitted from components of the Earth’s surface and lost back to the atmosphere. Q_E is the latent heat flux from the heat of vaporization of water vapors resulting from soil evaporation (E) and plant transpiration, generally measured as the composite evapotranspiration flux (ET).
7
Abdullah, Suhail, Kok Yeow You, Cheong Yew Chong, and Mohamed Sultan Mohamed Ali. "Milk Pasteurization and Characterization Using Mono-Mode Microwave Reactor and Slotted Coaxial Antenna." In Advances in Environmental Engineering and Green Technologies. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9420-8.ch005.
Der volle Inhalt der QuelleAnnotation:
Mono-mode microwave reactors are usually used to heat substances, especially food. This is because heating using a microwave reactor can sustain the flavor, color, and nutrition of the food. Furthermore, this heating technique is cost-effective and time-saving compared to a conventional heating method. The mono-mode reactor is able to determine the absorption of microwave power accurately on the heated substance versus a multimode reactor. In this chapter, a simple and precise mono-mode microwave reactor is designed and developed especially for research laboratories. The advantage of this reactor is to provide a more accurate calibration process, in order to improve the optimum energy use in the heating process, as well as the temperature of the specimen. The reactor can generate output power from 30 watts to 1500 watts, operating at 2.45±0.03 GHz and capable of accommodating a specimen volume of 780 cm3. Pure water is used as a heated specimen to demonstrate the performance and efficiency of this reactor.
8
Zhou, Zude, Huaiqing Wang, and Ping Lou. "Intelligent Process Planning." In Manufacturing Intelligence for Industrial Engineering. IGI Global, 2010. http://dx.doi.org/10.4018/978-1-60566-864-2.ch011.
Der volle Inhalt der QuelleAnnotation:
Computer Aided Process Planning is very hot topic in the manufacturing. It uses the geometric information (such as shape, size, etc.) and information technology (such as materials, heat treatment, bulk, etc.) which are input into the computer to output parts of the route of the process and the procedures automatically. Process planning is very important in the manufacturing process. With the continuous development of the manufacturing sector, the traditional manual methods of Process Planning flaws more and more serious. Computer-aided technology can increase their technical capacity effectively. CAPP is an effective means to improve the design. The research of CAPP has got a very huge development, from the search logic structure, Variant, Generative, and Hybrid to Expert System. In the future, the development of the CAPP will focus on the extending of the application scope, depth and level. In this chapter, a general introduction is presented firstly. Then the application of genetic algorithm (GA) to CAPP is introduced. Thirdly implement of ANN in CAPP System is presented. In the fourth part, use of Case-Based Reasoning in CAPP is discussed. Fourthly, CAPP based on Multi-Agent (MAS) system is illustrated.
9
Martinho Simões, José A., and Manuel Minas da Piedade. "Titration Calorimetry." In Molecular Energetics. Oxford University Press, 2008. http://dx.doi.org/10.1093/oso/9780195133196.003.0015.
Der volle Inhalt der QuelleAnnotation:
Titration calorimetry is a method in which one reactant inside a calorimetric vessel is titrated with another delivered from a burette at a controlled rate. This technique has been adapted to a variety of calorimeters, notably of the isoperibol and heat flow types. The output of a titration calorimetric experiment is usually a plot of the temperature change or the heat flow associated with the reaction or physical interaction under study as a function of time or the amount of titrant added. A primary use of titration calorimetry is the determination of enthalpies of reaction in solution. The obtained results may of course lead to enthalpies of formation of compounds in the standard state by using appropriate thermodynamic cycles and auxiliary data, as described in chapter 8 for reaction-solution calorimetry. Moreover, when reactions are not quantitative, both the equilibrium constant and the enthalpy of reaction can often be determined from a single titration run. This also yields the corresponding ΔrGo and ΔrSo through equations 2.54 and 2.55. Extensive use has been made of titration calorimetry as an analytical tool. These applications, which are outside the scope of this book, have been covered in various reviews. The historical development of titration calorimetry has been addressed by Grime. The technique is credited to have been born in 1913, when Bell and Cowell used an apparatus consisting of a 200 cm3 Dewar vessel, a platinum stirrer, a thermometer graduated to tenths of degrees, and a volumetric burette to determine the end point of the titration of citric acid with ammonia from a plot of the observed temperature change against the volume of ammonia added. The capabilities of titration calorimetry have enormously evolved since then, and the accuracy limits of modern titration calorimeters are comparable to those obtained in conventional isoperibol or heat-flow instruments. The titration procedures described in the literature can be classified as continuous or incremental, depending on the mode of titrant addition. In the first case the titrant is continuously introduced in the reaction vessel at a programmed (not necessarily constant) rate during a run.
10
Floudas, Christodoulos A. "Mixed-Integer Nonlinear Optimization." In Nonlinear and Mixed-Integer Optimization. Oxford University Press, 1995. http://dx.doi.org/10.1093/oso/9780195100563.003.0011.
Der volle Inhalt der QuelleAnnotation:
This chapter presents the fundamentals and algorithms for mixed-integer nonlinear optimization problems. Sections 6.1 and 6.2 outline the motivation, formulation, and algorithmic approaches. Section 6.3 discusses the Generalized Benders Decomposition and its variants. Sections 6.4, 6.5 and 6.6 presents the Outer Approximation and its variants with Equality Relaxation and Augmented Penalty. Section 6.7 discusses the Generalized Outer Approximation while section 6.8 compares the Generalized Benders Decomposition with the Outer Approximation. Finally, section 6.9 discusses the Generalized Cross Decomposition. A wide range of nonlinear optimization problems involve integer or discrete variables in addition to the continuous variables. These classes of optimization problems arise from a variety of applications and are denoted as Mixed-Integer Nonlinear Programming MINLP problems. The integer variables can be used to model, for instance, sequences of events, alternative candidates, existence or nonexistence of units (in their zero-one representation), while discrete variables can model, for instance, different equipment sizes. The continuous variables are used to model the input-output and interaction relationships among individual units/operations and different interconnected systems. The nonlinear nature of these mixed-integer optimization problems may arise from (i) nonlinear relations in the integer domain exclusively (e.g., products of binary variables in the quadratic assignment model), (ii) nonlinear relations in the continuous domain only (e.g., complex nonlinear input-output model in a distillation column or reactor unit), (iii) nonlinear relations in the joint integer-continuous domain (e.g., products of continuous and binary variables in the scheduling/ planning of batch processes, and retrofit of heat recovery systems). In this chapter, we will focus on nonlinearities due to relations (ii) and (iii). An excellent book that studies mixed-integer linear optimization, and nonlinear integer relationships in combinatorial optimization is the one by Nemhauser and Wolsey (1988). The coupling of the integer domain with the continuous domain along with their associated nonlinearities make the class of MINLP problems very challenging from the theoretical, algorithmic,and computational point of view. Apart from this challenge, however, there exists a broad spectrum of applications that can be modeled as mixed-integer nonlinear programming problems.
Konferenzberichte zum Thema "Heat output from the switchgear"
1
Creary, Andron, Matthew F. King, Matthew Langston, Cable Kurwitz, Paul Nelson, and Fatma Yilmaz. "Time Domain Analysis of the Temperatures in an Electrical Auxiliary Building Room." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75720.
Der volle Inhalt der QuelleAnnotation:
A computational fluid dynamics (CFD) model has been developed to predict air temperatures within the switchgear room environment of a nuclear plant’s Electronics Auxiliary Building (EAB). In order to validate the CFD model output, a scale model experiment has been developed using an analytical model to properly scale important EAB room parameters to allow small scale experiments to be performed for validation of the CFD model. The focus of this paper is the development of the methodology used to accurately predict the bulk air temperature or the EAB room. The CFD model is compared to a simple lumped parameter model as well as a scale model experiment. The scaling approach matches the eigenvalues of the lumped parameter model. An experiment based on this scaling approach was performed and compared with CFD output. The time predicted by the CFD model of the Electrical Auxiliary Building room for the average air temperature to increase from 17.7 °C (64 °F) to 40 °C (104 °F) is 23.5 minutes. The lumped parameter analytic solution produces a mean time of 22 minutes. The heat up time for the experiment matches the CFD model providing confidence in the fidelity of the CFD model.
2
Sun, Shuo, Li-an Chen, Yi-min You, and Zong-xiong Ma. "Thermal analysis of switchgear using FEM considering the heat from the main circuit." In 2017 4th International Conference on Electric Power Equipment - Switching Technology (ICEPE-ST). IEEE, 2017. http://dx.doi.org/10.1109/icepe-st.2017.8188952.
Der volle Inhalt der Quelle
3
Woods, Melvin, Walter Bryzik, and Ernest Schwarz. "Heat Rejection from High Output Adiabatic Diesel Engine." In International Congress & Exposition. SAE International, 1992. http://dx.doi.org/10.4271/920541.
Der volle Inhalt der Quelle
4
Klein, A. C., L. L. Zahm, S. E. Binney, et al. "Anomalous heat output from Pd cathodes without detectable nuclear products." In Anomalous nuclear effects in deuterium/solid systems. AIP, 1991. http://dx.doi.org/10.1063/1.40696.
Der volle Inhalt der Quelle
5
Příhoda, Miroslav, Jozef Vlček, Marek Velička, Mária Čarnogurská, and René Pyszko. "Heat output of the recuperator for preheating natural gas from a mobile container device." In THE MEETING OF DEPARTMENTS OF FLUID MECHANICS AND THERMOMECHANICS (35MDFMT): Proceedings of the 35th Meeting of Departments of Fluid Mechanics and Thermomechanics. Author(s), 2016. http://dx.doi.org/10.1063/1.4963038.
Der volle Inhalt der Quelle
6
Ibrahim, O., P. Zimmermann, C. Hirsch, T. Sattelmayer, B. Gerhard, and C. Steinbach. "A Microturbine Operating With Variable Heat Output." In ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-53011.
Der volle Inhalt der QuelleAnnotation:
The concept of variable heat output using a recuperator bypass has been studied on a microturbine. The target of this research is to quantify to which extent variable heat output is possible using an existing microturbine design. In the paper we compare the predicted and measured performance of the system as well as present and discuss the change of NOx emissions resulting from overfiring the microturbine combustor when reducing the air preheating temperature in bypass mode. We clarify which choice of bypass is suitable considering in particular the recuperator thermo-mechanical loading. We show that the performance of the system in variable heat output can be well extrapolated with a thermodynamic model calibrated with the normal operation mode data and how experimental or theoretical data can be used to predict the change of NOx emission. It is shown that the full benefit of variable heat output can only be gained with a modified combustor design. As an example for this a lean-lean staged combutor concept is proposed.
7
Hrabovský, Peter. "Measurement of Heat Output of a Loop Heat Pipe with Radiation Heating." In 2nd International Conference on Research in Science, Engineering and Technology. Acavent, 2019. http://dx.doi.org/10.33422/2nd.icrset.2019.11.787.
Der volle Inhalt der QuelleAnnotation:
The paper focuses on the ways of heat transfer due to the phase-phase change from liquid to gaseous and vice versa. Described herein are heat transfer devices through a heat pipe and methods for transferring heat from a heat source to a point of consumption. A heat pipe is a device described in the literature as a material with more than 100 times higher thermal conductivity than copper. A heat pipe is an energy-efficient device without the need for an electrically powered element (circulation pump). The aim of this experiment is to construct a loop heat pipe device. Construction of the cooling circuit and ensuring sufficient cooling capacity by external cooling sources. Construction of a heating circuit in the form of a heat source and its regulation of heat output. Another objective is to measure the input and output parameters of the device and to calculate the resulting heat output of the loop heat pipe. The device itself is a cooling system for the removal of generated or waste heat from technological elements such as: electrical transformers, biomass and fossil fuel combustion processes, cooling of high-performance computer workstations, etc. Another objective is to select a suitable heat transfer medium. The right choice guarantees the optimal use of the loop heat pipe device in the optimum temperature working environment while minimizing the formation of non-condensable gases generated by the chemical reactions of the loop heat pipe material itself and the heat transfer medium. This selection greatly affects the cooling performance of the device.
8
Simeunovic´, Goran, Pavel Zitek, and Jan Chysky´. "The Parameters Identification of Time - Delay Models of Heat Transfer Systems From Input-Output Measurements." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75361.
Der volle Inhalt der QuelleAnnotation:
The paper presents the identification issues and proposes a parameter identification algorithm that separates the system parameters from the time-delays for a class of single input single output (SISO) linear time delay systems (LTDS). The presence of the unknown time delay greatly complicates the parameters estimation problem, because the parameters of the model are not linear with respect to the time-delay. However, once the time delay is determined, the model becomes linear for the other parameters and hence the common least square method can be utilized directly. Motivated by the nonlinear least squares problem developed in the paper Golub and Pereyra (1973), a novel modification of the so-called variable projection functional is worked out for identification of time delays. In this way, the parameters estimation is separated from the estimation of time delays and the large errors in the parameter estimates, in the case of presence of errors in the time-delay identified values, are avoided. Namely, the small error in the time-delay identified values may often cause a large error in the system parameters identification. A hybrid optimalization method combining a Genetic Algorithm and Nelder-Mead technique is used for minimization of variable projection functional for the identification of time delays. This approach is illustrated by a particular application in the field of heat transfer, concretely on the time-delay model of the recuperative heat exchanger.
9
LeBlanc, S. A., Y. Gao, and K. E. Goodson. "Thermoelectric Heat Recovery From a Tankless Water Heating System." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68860.
Der volle Inhalt der QuelleAnnotation:
Thermoelectric cogeneration promises to recover waste heat energy from a variety of combustion systems. There is a need for computationally efficient simulations of practical systems that allow optimization and illustrate the impact of key material and system parameters. Previous research investigated thermoelectric material enhancement and thermoelectric system integration separately. This work connects material parameters and system integration. We develop a thermal simulation for a 15kW tankless, methane-fueled water heater with thermoelectric modules embedded within a cross-flow heat exchanger. The simulation employs a finite volume method for the two fluids. It links external convection with a surface efficiency of 85%, internal convection for laminar flow, and conduction through the system in order to determine power generation within the thermoelectric. For a single pipe in the water heater system, 126 W of electrical power can be generated, and a typical system could yield 370 W. Realization of effective cogeneration systems hinges on investigating the impact of thermoelectric material parameters coupled with system parameters, so the impact of varying flow rate, convection coefficient, TEM thermal conductivity, Seebeck coefficient, and thermal interface materials are investigated. While varying parameters can improve thermoelectric output by over 50%, thermal interface materials can severely limit cogeneration system power output.
10
Bryzik, Walter, Ernest Schwarz, Roy Kamo, and Melvin Woods. "Low Heat Rejection From High Output Ceramic Coated Diesel Engine and Its Impact on Future Design." In International Congress & Exposition. SAE International, 1993. http://dx.doi.org/10.4271/931021.
Der volle Inhalt der Quelle