Log in

Relevant bibliographies by topics / Coiled tubes

Contents

Journal articles
Dissertations / Theses
Books
Book chapters
Conference papers
Reports

Academic literature on the topic 'Coiled tubes'

Author: Grafiati

Published: 6 September 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Coiled tubes.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Coiled tubes"

1

Akgul, Dogan, Safak Metin Kirkar, Busra Selenay Onal, Ali Celen, Ahmet Selim Dalkilic, and Somchai Wongwises. "Single-phase flow heat transfer characteristics in helically coiled tube heat exchangers." Kerntechnik 87, no. 1 (February 1, 2022): 1–25. http://dx.doi.org/10.1515/kern-2021-1005.

Full text

Abstract:

Abstract The aim of this review is to present a summary of the published papers of the heat transfer and pressure drop characteristics for single-phase flow in helically coiled tubes. The effect of geometrical parameters such as curvature ratio, coil pitch and working conditions such as Reynolds number, Dean number, flow rate and flow arrangement on heat transfer and pressure drop in helically coiled tubes are determined in the light of the experimental, numerical and analytical studies in the literature. Also, the effect of using nanofluids in comparison with conventional fluids, using enhanced surfaces such as corrugated, micro-finned, dimpled with regards to smooth surfaces and wire coil insert usage in helically coiled tubes are discussed. The correlations proposed for determination of Nusselt number and friction factor in helically coiled tubes are presented in detail separately under laminar and turbulent flow regimes. The studies show that usage of helically coiled tube merely gives higher heat transfer rate and pressure drop in comparison to straight one, additionally, the heat transfer performance increases with the inclusion of the combination of other passive heat transfer enhancement methods to helically coiled tube. Moreover, the subject of single-phase flow in helically coiled tubes is ascertained to be worth researching due to the fact that there are limited number of studies and is still no empirical or analytical model/correlation in the case of using enhanced surfaces and wire coil insert. Forthcoming researches on this issue in the near future will be considered as pioneer ones in literature.

APA, Harvard, Vancouver, ISO, and other styles

2

Abdul- Kareem R. Abed, Hassan Jawdat Fadhiel, Gaydaa Mahsun, and Thabet C. Yassen. "Experimental Study on The Effect of Capillary Tube Geometry on The Performance of Vapour Compression Refrigeration System." Diyala Journal of Engineering Sciences 7, no. 2 (June 1, 2014): 47–60. http://dx.doi.org/10.24237/djes.2014.07204.

Full text

Abstract:

A domestic refrigerator of 5 ft3 capacity is used to study the effect of coiled diameter and pitch distance of a capillary tube. Five capillary tubes of 2 mm in diameter and 1500 mm length each are used, as same as original capillary tube of the refrigerator. The capillary tubes is formed in five shapes, each one has different coil diameter (D) namely 25, 50, 75, 100 and 125 mm in diameter, in addition three distances between each coil (pitch (P)) is tested, namely 6, 8 and 10 mm. The pressure at inlet and outlet of capillary are measured to calculate the cycle COP, as well as the power consumed by the cycle compressor is measured to calculate the mass flow rate of refrigerant. The work show that the coiled diameter of capillary tube affect the cycle COP strongly, as the capillary coiled diameter (D) increases from 25 to 100 mm the cycle COP increases from 2.8 to 3.7 when the cabinet temperature equals to 8oC. The increases of coiled diameter more than 100 mm shows insignificant effect on the cycle COP. While the pitch space of capillary tube coiled shows minor effect on the cycle COP. Moreover, to the mass flow rate of refrigerant increases with approximately ranges from 1.2−2.7

APA, Harvard, Vancouver, ISO, and other styles

3

INOUE, NORIHIRO, SHINITSU IKU, and KAZUHIDE WATANABE. "PRESSURE DROP AND HEAT TRANSFER INSIDE THE COILED FLOW CHANNEL OF SMOOTH TUBES AND INTERNALLY HELICAL-GROOVED TUBES." International Journal of Air-Conditioning and Refrigeration 20, no. 04 (December 2012): 1250023. http://dx.doi.org/10.1142/s201013251250023x.

Full text

Abstract:

In this study, we investigated ways of improving the performance of heat exchangers, which are the heat pumps for use in hot-water supply systems on the hot-water supply side. Therefore, we verified experimentally the pressure drop and the heat transfer characteristics within the coiled flow channel. Five smooth copper tubes and five internally helical-grooved copper tubes with an outside diameter of 12.7 mm and coil diameters of 100 mm, 120 mm, 140 mm, 160 mm and 180 mm were used as the heat-transfer coiled tubes in the experiments. Experiments were conducted under conditions of constant isothermal heating and fluid flow inside coiled tubes with an inlet temperature of 20°C, and the flow rates of the fluid flow inside the coiled tubes were adjusted and varied to change the Reynolds number within the range of 900 to 25,000. Based on the experimental values, we proposed prediction equations to systematically calculate the friction factor and the heat transfer coefficient for different curvature radius ratios.

APA, Harvard, Vancouver, ISO, and other styles

4

Dey, Anshumaan, and Monisha M. Mandal. "Hydrodynamics Study of Oil–Water Flow in Coiled Flow Inverter." Advanced Science, Engineering and Medicine 12, no. 2 (February 1, 2020): 173–80. http://dx.doi.org/10.1166/asem.2020.2485.

Full text

Abstract:

The present numerical study is an effort to examine the hydrodynamics characteristics of two immiscible liquids (oil and water) flowing in different tubes. i.e., straight, coiled and Coiled Flow Inverter (CFI) tube of equal dimensions. CFI is a novel device in which fluid flow inversion takes place at uniform interval length of tube. The effect of oil-water viscosity ratio (µoil/µwater = 1.6 and 30) on velocity contours, phase distribution and pressure drop in the different tubes were investigated. The present work show that flow pattern of oil–water flows was changed from stratified to annular flows at higher water volume fraction for µoil/µwater = 1.6 in CFI. Phase inversion of oil–water flow was observed in CFI at higher viscosity ratio (µoil/µwater = 30). There was remarkable reduction in pressure drop with the increment in volume fraction of water flowing in coiled as well as CFI. CFI being more compact can be efficiently used in industries as chemical reactor, heat exchanger, mixer, etc.

APA, Harvard, Vancouver, ISO, and other styles

5

Akeedy, Adnan Rasheed, Hajar Alias, and Sami D. Salman. "HEAT TRANSFER ENHANCEMENT USING PASSIVE TECHNIQUE: REVIEW." Jurnal Teknologi 83, no. 2 (February 28, 2021): 151–62. http://dx.doi.org/10.11113/jurnalteknologi.v83.14546.

Full text

Abstract:

Preserving and saving energy have never been more important, thus the requirement for more effective and efficient heat exchangers has never been more important. However, in order to pave the way for the proposal of a truly efficient technique, there is a need to understand the shortcomings and strengths of various aspects of heat transfer techniques. This review aims to systematically identify these characteristics two of the most popular passive heat transfer techniques: nanofluids and helically coiled tubes. The review indicated that nanoparticles improve thermal conductivity of base fluid and that the nanoparticle size, as well as the concentrations of the nanoparticles plays a major role in the effectiveness of the nanofluids. Regarding the helically coiled tubes, it was discovered that the use of a coiled tube produces secondary flows, which ultimately improves the heat transfer enhancement. The third part of the review focused on microchannels and microtubes. This is mainly due to the growing need and requirement of smaller and more compact thermal cooling systems. Thus, ultimately the result of the review indicates that a combination of all these three techniques can lead to a compact and minimized heat exchanger that uses the benefits obtained from both nanofluids and helically coiled tubes in order to improve the heat transfer rate of the thermal systems.

APA, Harvard, Vancouver, ISO, and other styles

6

Gao, Weikai, Xiaoyang Xie, Xiaowei Li, and Xinxin Wu. "Influence of Coiling Direction of Helical Tube Bundles on the Thermal-Hydraulics of the HTGR Steam Generator." Journal of Physics: Conference Series 2048, no. 1 (October 1, 2021): 012032. http://dx.doi.org/10.1088/1742-6596/2048/1/012032.

Full text

Abstract:

Abstract Helical tube bundles were usually adopted in the steam generators (SGs) or intermediate heat exchangers (IHXs) of high temperature gas-cooled reactors (HTGRs). Heat transfer tubes in neighboring tube layers can be coiled in the same direction or in the opposite direction. The coiling direction has influences on the thermal-hydraulic performances of the SGs or IHXs. The cross flow convection over helical tube bundles with neighboring tube layers having the same coiled direction and opposite coiled direction were numerically investigated. Reynolds stress model with standard wall functions was used for the turbulence modeling. For a helical tube bundle with neighboring layers coiled in the same direction (parallel tube layers), the tangential velocity along the coiled circumferential direction could be observed obviously. For a helical tube bundle with neighboring layers coiled in the opposite direction (crossed tube layers), there is no average tangential velocity of the whole flow filed. And the streamlines of the fluid are very complex. The flow resistances and heat transfer coefficients over helical tube bundle with parallel tube layers and crossed tube layers were compared. Although the heat transfer over helical tube bundles with crossed tube layers was 9.39% smaller than that with parallel tube layers, the pressure drop over tube bundle with crossed tube layers was much smaller compared with those with parallel tube layers.

APA, Harvard, Vancouver, ISO, and other styles

7

Garimella, S., D. E. Richards, and R. N. Christensen. "Experimental Investigation of Heat Transfer in Coiled Annular Ducts." Journal of Heat Transfer 110, no. 2 (May 1, 1988): 329–36. http://dx.doi.org/10.1115/1.3250488.

Full text

Abstract:

Forced convection heat transfer in coiled annular ducts was investigated experimentally. Average heat transfer coefficients were obtained for both laminar and transition flows. Two coiling diameters and two annulus radius ratios were used in the study. The data were correlated with Dean number and Reynolds number separately and compared with the available studies of coiled circular tubes and straight annular ducts. It was found that coiling augments the heat transfer coefficients above the values for a straight annulus especially in the laminar region. However, the augmentation is less than would be expected for a coiled circular tube. The augmentation decreases as the flow enters the transition region.

APA, Harvard, Vancouver, ISO, and other styles

8

Haryoko, Luthfi A. F., Jundika C. Kurnia, and Agus P. Sasmito. "Numerical Investigation of Subcooled Boiling Heat Transfer in Helically-Coiled Tube." International Journal of Automotive and Mechanical Engineering 17, no. 1 (March 30, 2020): 7675–86. http://dx.doi.org/10.15282/ijame.17.1.2020.15.0570.

Full text

Abstract:

Subcooled boiling heat transfer in helically-coiled tubes offers better heat transfer performance than any other types of boiling processes due to its ability to capture high heat flux with a relatively low wall superheat. This study investigates turbulent subcooled forced convection boiling performances of water-vapour in a helically-coiled tube with various operating conditions i.e. operating pressure, heat, and mass flux. Developed CFD model is validated against previously published experimental results using the RPI model. The model is developed based on the Eulerian-Eulerian framework coupled with k-ε RNG turbulence model and Standard Wall-Function. A good agreement is found between numerical prediction and experimental counterpart for the bulk fluid temperature and non-dimensional length. The result indicates that the subcooled boiling heat transfer in a helically-coiled tube tends to improve heat transfer coefficient and pressure drop in the domain. Subcooled boiling starts at the inner side of the helically-coiled tube (f=9900) due to the existence of secondary flow that comes from the coil curvature. Heat transfer coefficient and pressure drop increased with increasing heat flux and decreasing mass flux, and operating pressure. This is caused by the bubble movement and convective heat transfer phenomena in a helically-coiled tube. Finally, this study can provide a guideline for future research of the subcooled boiling in a helically-coiled tube.

APA, Harvard, Vancouver, ISO, and other styles

9

Mishani, Siamak, Brian Evans, Vamegh Rasouli, Reem Roufail, Soren Soe, and Peter Jaensch. "Interlaminar modelling to predict composite coiled tube failure." APPEA Journal 55, no. 1 (2015): 361. http://dx.doi.org/10.1071/aj14029.

Full text

Abstract:

In a field operation that uses coiled tubing in its applications, fibre-reinforced polymer matrix composite tubing is seldom used. Fibre-composite coiled tubes offer advantages, compared to steel material, through a reduction in weight and improvement in fatigue life. The stiffness of composite material degrades progressively when increasing the number of cyclic loading. The fatigue damage and failure criteria of fibre-reinforced composite coiled tubes are more complex than that of steel; hence, failure predictions are somewhat unreliable. Among the defects in composite materials, interlaminar delamination is the foremost problem in fibre-reinforced composite material, and it leads to a reduction in strength and stiffness especially in cyclic-load conditions. Delamination causes a redistribution of the load path along the composite structure, which is unpredictable; therefore, delamination in a composite coiled tube in an oil and gas field eventually leads to final failure, which could be catastrophic. A-ply-by-ply mathematical modelling and numerical simulation method was developed to predict interlaminar delamination of filament-wound composite coiled tubes under a combination of different loading scenarios with consideration to low-cycle fatigue. The objective of this paper is to explain interlaminar delamination as an initial crack and source of stress concentration in composite coiled tubes in the framework of meso-cracking progression of matrix damage modelling of composite laminates. The paper focuses on delamination failure because the largest span of the composite lifecycle is at the crack propagation phase, which manifests itself in the form of delamination. The analysis shows that the crack front tip is not uniform, and also shows that carbon fibre possesses higher stiffness values compared to glass fibre. The paper confirms that 2D modelling cannot express the real release strain energy rate at the crack front tip. Mode-I testing, however, showed that the double cantilever beam (DCB) only represents the normal stress from the release strain energy rate. The results also indicated that there were other sources contributing to the strain energy release rate, such as inter-layer frictions and normal stress in the end notched flexure (ENF) testing mode.

APA, Harvard, Vancouver, ISO, and other styles

10

Quinlan, R. A., and M. Stewart. "Crystalline tubes of myosin subfragment-2 showing the coiled-coil and molecular interaction geometry." Journal of Cell Biology 105, no. 1 (July 1, 1987): 403–15. http://dx.doi.org/10.1083/jcb.105.1.403.

Full text

Abstract:

We have produced crystalline tubes of chicken breast myosin long subfragment-2 that show order to resolutions better than 2 nm. The tubes were formed from a thin sheet in which the myosin long subfragment-2 molecules were arranged on an approximately rectangular crystalline lattice with a = 14.1 +/- 0.2 nm and b = 3.9 +/- 0.1 nm in projection. Shadowing indicated that the tube wall was approximately 7 nm thick and that the sheets from which it was formed followed a right-handed helix. Superposition of the lattices from the top and bottom of the tube produced a moire pattern in negatively stained material, but images of single sheets were easily obtained by computer image processing. Although several molecules were superimposed perpendicular to the plane of the sheet, the modulation in density due to the coiled-coil envelope was clear, indicating that the coiled-coils in these molecules were in register (or staggered by an even number of quarter pitches). In projection the coiled-coil had an apparent pitch of 14.1 nm (the axial repeat of the unit cell), but the small number of molecules (probably four) superimposed perpendicular to the plane of the sheet meant that pitches within approximately 1 nm of this value could have shown a modulation. Therefore, a more precise determination of the coiled-coil pitch must await determination of the sheet's three-dimensional structure. The coiled-coils of adjacent molecules within the plane of the sheet were staggered by an odd number of quarter pitches. This arrangement was similar to that between paramyosin molecules in molluscan thick filaments and may have features in common with other coiled-coil protein assemblies, such as intermediate filaments. Each molecule in the crystal had two types of neighbor: one staggered by an odd number of quarter pitches and the other by an even number of quarter pitches, as has been proposed for the general packing of coiled-coils (Longley, W., 1975, J. Mol. Biol., 93:111-115). We propose a model for the detailed packing within the sheet whereby molecules are inclined slightly to the plane of the sheet so that its thickness is determined by the molecular length.

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Coiled tubes"

1

Mao, Jie. "Falling film absorption on horizontal and coiled tubes /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487942182324639.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Elsayed, Ahmed Mohamed. "Heat transfer in helically coiled small diameter tubes for miniature cooling systems." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/2907/.

Full text

Abstract:

This thesis describes experimental and theoretical investigation on the use of small diameter helically coiled tubes for the evaporator of miniature refrigeration systems. A detailed review of past experimental and theoretical work on boiling heat transfer inside helically coiled tubes is presented. As most of past work was conducted on helical coils with tube diameters larger than 6 mm, a brief review of the flow boiling heat transfer process inside straight tubes with small diameters of less than 3 mm is also presented. An experimental facility was constructed and instrumented to investigate the flow boiling of refrigerant R134a in helically coiled tubes with diameters ranging from 2.8 mm to 1.1 mm and coil diameter ranging from 30 mm to 60 mm. The experimental results showed that decreasing the tube diameter increases the boiling heat transfer coefficient by up to 58% while decreasing the coil diameter increased the boiling heat transfer coefficients more significantly by up to 130% before dryout. Dimensional analysis using Pi theorem and Artificial Neural Network (ANN) techniques were used to develop correlations to predict the flow boiling heat transfer coefficients inside helically coiled tubes. The ANN method produced a better prediction of the experimental results with ±30%. The experimental facility was equipped with a reciprocating compressor and a manual expansion device and instrumented to assess the performance of miniature vapour compression refrigeration system. A mathematical model of this miniature system was developed, validated and then used to optimise the system performance in terms of the geometry of the helical coils used in the evaporator and condenser. It was shown that the smaller the coil diameter, the better the performance of cooling system. For the same evaporator length, the larger the tube diameter, the larger surface area and better COP. Smaller tube diameters showed better performance at lower area ratios. However, smaller tube diameters showed lower performance at high area ratios due to the large pressure drop caused by smaller tubes in case of using high area ratios. Finally, the addition of AL2O3 nanoparticles to pure water was investigated using computational fluid dynamics technique (CFD) in terms of heat transfer and pressure drop of single phase laminar and turbulent fluid flow in both straight and helically coiled tubes. The tested AL2O3 nanofluid in helical coils produced up to 350% increase in the heat transfer coefficient of the laminar flow compared to pure water in straight tubes for the same flow conditions. However, insignificant enhancement of the heat transfer was obtained in the turbulent flow regime. Also, the use of high AL2O3 nanofluid concentration of above 2% was found to produce significant pressure drop penalty factor of 5 times that of pure water in straight tubes.

APA, Harvard, Vancouver, ISO, and other styles

3

Zhang, Hongyang. "Experimental Study of Cuttings Transport in Coiled Tube Micro-Borehole Drilling." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/68365.

Full text

Abstract:

This research presented an experimental study of the cuttings transport in vertical micro boreholes. The cuttings settling and transport velocities were obtained under various conditions of cuttings (size, concentration) and fluid properties (flow rate, rheology) and annulus geometry. The results showed that it is inaccurate to predict the cuttings transport velocity based on the cuttings settling velocity. The lab results were compared with a series of field tests in both vertical annulus and curved pipe.

APA, Harvard, Vancouver, ISO, and other styles

4

Wiedmeyer, Viktoria [Verfasser], and Kai [Gutachter] Sundmacher. "Continuous crystallization in a helically coiled flow tube crystallizer / Viktoria Wiedmeyer ; Gutachter: Kai Sundmacher." Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2020. http://d-nb.info/1219965286/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Wiedmeyer, Viktoria Verfasser], and Kai [Gutachter] [Sundmacher. "Continuous crystallization in a helically coiled flow tube crystallizer / Viktoria Wiedmeyer ; Gutachter: Kai Sundmacher." Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2020. http://d-nb.info/1219965286/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Mishani, Siamak. "Investigation of fatigue failure in composite versus steel coiled tube for application in mine site drilling." Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/59665.

Full text

Abstract:

Composite coiled tubing could be an economic alternative to the use of steel for exploration drilling due to its potentially greater reliability and higher fatigue life. This PhD study investigated the fatigue life of steel versus composite tubes using both numerical modelling and laboratory scale tests. Results were validated by statistical analysis and confirmed that composite tubing has a higher fatigue life, and potentially opens up a new market place for composite drill pipe.

APA, Harvard, Vancouver, ISO, and other styles

7

Prabhanjan, Devanahalli G. "Influence of coil characteristics on heat transfer to Newtonian fluids." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36910.

Full text

Abstract:

A water bath thermal Processor was designed and built to study the influence of helical coil characteristics on heat transfer to Newtonian fluids like water and base oil with three different viscosities. The system consisted of a thermally insulated water bath, an electric heater, pump to re-circulate water in the bath and for pumping the processing fluid through the coil, copper helical coils and a storage tank for the processing fluid.
Comparative study has shown that the outer and total heat transfer coefficients were significantly lower in natural than in forced convection water bath. However, inner heat transfer coefficient was not significantly affected. Flow rate as low as 0.001 m.s-1 in the water bath improved the outer and total heat transfer coefficients by 35 and 22% respectively. One could expect a higher rate with an increase in water re-circulation rate inside the water bath. Percent rise in heat transfer was limited to seven with respect to inner heat transfer. With the Pearson correlation, it was possible to express total heat transfer rate directly in terms of outer and inner rates. Significant interactions were observed between variables and constants.
Experiments with 2 pitch cases were conducted with water to water heat transfer using coils to determine the Nusselt number correlation for natural convection. Characteristic lengths were changed in the models. The Nusselt number was under-predicted by 25 to 37% for water bath temperatures of 75° and 95°C respectively. Flow rate inside the coil had slight effect on Nusselt number due to change in the temperature gradient along the length of the coil.
Studies conducted with three base oils have shown significant difference in viscosity after heating the oil for several turns. Each fluid was heated in a distinct flow regime. The observed Nusselt number inside the coil for low Reynolds number was as high as an order of magnitude than the predicted values calculated by Seider-Tate relation for laminar flow. Vorticies formed associated with the eddy structure could very well be the cause for this kind of rise in the value.
Preliminary study conducted has shown a higher rise in temperature of processing fluid in case of helical coil compared to that of a straight tube. Larger the diameter of the tube better was the heat transfer. An elevated bath temperature had higher heat transfer.

APA, Harvard, Vancouver, ISO, and other styles

8

Geier, Martin. "Influência dos parâmetros envolvidos no processo de união por interferência de tubos por cravamento eletromagnético." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/96295.

Full text

Abstract:

A união por conformação eletromagnética de perfis tubulares de alta condutividade elétrica é um processo inovador e limpo que pode substituir com sucesso os processos convencionais de união baseados na fixação mecânica por parafusos, rebites, soldagem e adesivos estruturais. Esta tecnologia funciona a temperatura ambiente, permite a união de materiais diferentes e oferece potencial para promover novas aplicações na montagem de estruturas leves. Neste trabalho busca-se compreender a união por interferência de tubos por cravamento eletromagnético em termos de seus principais parâmetros com o objetivo de identificar a influência na resistência global das uniões e estabelecer a faixa útil de condições operacionais do processo. Inicialmente são apresentados os fundamentos teóricos do processo de conformação eletromagnética e suas principais variantes operacionais, seguido de um resumo do estado atual do conhecimento da aplicação desta tecnologia na união de perfis tubulares no qual é verificado que os parâmetros mecânicos são a tensão residual no mandril, a área e forma da zona de união e o coeficiente de atrito entre os componentes. Entretanto, tais parâmetros estão relacionados de forma complexa com o processo de cravamento eletromagnético, a começar pela energia e a distribuição do pulso de pressão magnética gerados pela máquina e ferramenta que “disparam” o processo de conformação, a folga inicial entre componentes, o material dos componentes e, a geometria, forma e rugosidade do mandril. O estudo experimental foca a união por interferência de tubos de alumínio (AA6082-O) com mandris de aço (AISI 1045) e alumínio (AA6082 nos estados O e T6) investigando de forma gradual a influência de parâmetros do processo na resistência mecânica (à tração) deste tipo de uniões. Os resultados obtidos demonstram que a resistência mecânica da união e os modos de falha associados são diretamente relacionados com os parâmetros de processo e condições do mandril. Além disso, outras importantes contribuições são apresentadas em relação à instrumentação para medição de fluxo magnético e eficiência global do processo e para o desenvolvimento e aplicações industriais desta tecnologia.
Joining of tubular profiles with high electrical conductivity by electromagnetic forming (EMF) is an innovative and clean technology that can successfully replace conventional joining technologies based on mechanical fixing with fasteners, rivets, welding and structural adhesives. The technology works at room temperature, allows joining dissimilar materials and offers potential to foster new applications in the assembly of lightweight tubular frame structures. This work investigates the interference-fit joining of tubes by electromagnetic crimping in terms of its major parameters with the aim of identifying their influence on the overall strength of the joints and establishing the useful range of process operating conditions. Initially, the theoretical principles of EMF and its main operational process variants are presented, followed by a summary of the current state of the knowledge of its application in the joining of tubular profiles in which it is found that the mechanical parameters are the residual stress at the joint interface, the area and shape of the joint interface and the friction coefficient between the joining partners. However, these parameters are related in a very complex way with the electromagnetic crimping process parameters, starting with the charging energy and by the machine and tool which generates the distribution of the magnetic pressure pulse that “triggers” the forming process, the initial gap between joining partners, the mandrel properties such as material, geometry, shape and surface roughness. The experimental study focuses the interference-fit of aluminum tubes (AA6082-O) on mandrels made of different materials and metallurgical conditions (AISI 1045, AA6082-O and AA6082-T6) and, therefore, the process is analyzed by the gradual influence of other process parameters aiming to achieve high strength joints. Results show that the joint strength and the associated failure mechanisms are directly related to process parameters and mandrel conditions. In addition, other important contributions are presented regarding the instrumentation for measuring the magnetic flux and overall process efficiency and to the development and implementation of this technology in industrial processes.

APA, Harvard, Vancouver, ISO, and other styles

9

Anderson, Brian Eric. "Derivation of Moving-Coil Loudspeaker Parameters Using Plane Wave Tube Techniques." BYU ScholarsArchive, 2004. https://scholarsarchive.byu.edu/etd/17.

Full text

Abstract:

Small-signal moving-coil loudspeaker driver parameters are traditionally derived through electrical impedance measurement techniques. These parameters are commonly called Thiele/Small parameters, after Neville Thiele and Richard Small who are credited with developing industry-standard loudspeaker modeling techniques. However, because loudspeaker drivers are electro-mechano-acoustical transducers, it should be possible to measure their parameters in physical domains other than the electrical domain. A method of measuring loudspeaker parameters from the acoustical domain will be developed. The technique uses a plane wave tube to measure acoustical properties of a baffled driver under test. Quantities such as the transmission loss through the driver are measured for a driver placed in the tube using the two-microphone transfer-function technique. Models have been developed to curve fit the resulting data, from which small-signal loudspeaker parameters are subsequently derived. This thesis discusses the acoustical measurement theory, apparatus, and system modeling methods (via equivalent circuits). It also compares measured parameters to those derived using electrical techniques. Parameters derived from both approaches are compared with reference values to establish bias errors. Sequential measurements are also compared to reveal random errors in the derivation processes.

APA, Harvard, Vancouver, ISO, and other styles

10

Lagat, Christopher Kipchumba. "Evaluation and selection of an optimum material for coil tubes in CT drilling technology for hard rocks in mineral exploration." Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/116.

Full text

Abstract:

The PhD study aimed at evaluating and selecting optimum material for coiled tubes in CT drilling technology for hard rocks in mineral exploration. Numerical computer modelling, using Abaqus and Hypersizer software packages, was undertaken to analyse stress distribution and investigate the effect of fibre orientation and stacking sequence of fibre layers that constitute the composite tube laminate. Cyclic bending tests using a fatigue testing machine and mechanical tensile tests were carried out to validate the simulation results.

APA, Harvard, Vancouver, ISO, and other styles

More sources

Books on the topic "Coiled tubes"

1

Society of Petroleum Engineers (U.S.), ed. Coiled-tubing technology. Richardson, Tex: Society of Petroleum Engineers, 1994.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

2

The International Coiled Tubing Association. Coiled Tubing Welding Specification for Tube-to-tube Welds. Society of Petroleum, 1999.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

3

Corum, James F., and Kenneth L. Corum. Vacuum Tube Tesla Coils. Corum & Associates, Incorporated, 1988.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

4

Parker, Philip M. The 2007-2012 World Outlook for Shell-And-Tube, Shell-And-Coil, Shell-And-U-Tube, and Tube-In-Tube Condensers for Heat Transfer. ICON Group International, Inc., 2006.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

5

The 2006-2011 World Outlook for Shell-And-Tube, Shell-And-Coil, Shell-And-U-Tube, and Tube-In-Tube Condensers for Heat Transfer. Icon Group International, Inc., 2005.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

6

Parker, Philip M. The 2007-2012 World Outlook for Shell-And-Tube, Shell-And-Coil, Shell-And-U-Tube, and Tube-In-Tube Liquid Coolers for Heat Transfer. ICON Group International, Inc., 2006.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

7

The 2006-2011 World Outlook for Shell-And-Tube, Shell-And-Coil, Shell-And-U-Tube, and Tube-In-Tube Liquid Coolers for Heat Transfer. Icon Group International, Inc., 2005.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

8

Seipel, Catherine P., and Titilopemi A. O. Aina. Tracheoesophageal Fistula Repair. Edited by Erin S. Williams, Olutoyin A. Olutoye, Catherine P. Seipel, and Titilopemi A. O. Aina. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190678333.003.0048.

Full text

Abstract:

Tracheoesophageal fistula (TEF) with esophageal atresia (EA) is a congenital malformation occurring in approximately 1:4,000 live births. TEF/EA is characterized by disrupted continuity of the esophagus. There are five distinct types, but the most common is EA with a distal TEF. Most cases are diagnosed postnatally after an inability to pass a nasogastric tube (NGT), with subsequent radiographic imaging finding the NGT coiled within the esophageal pouch. The anesthetic management of TEF/EA repair can be complicated by the presence of cardiac, renal, and vertebral anomalies. Additionally, ventilation can be challenging, and care must be taken to minimize insufflation of the stomach through the fistula. Postoperative analgesia should include consideration of intravenous opioids, nonopioid adjunct medications, and regional and neuraxial techniques.

APA, Harvard, Vancouver, ISO, and other styles

9

The 2006-2011 World Outlook for Air Conditioning-And Refrigeration-Type Central System Standard Steam and Steam Distributing Tube Finned Coils. Icon Group International, Inc., 2005.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

10

Parker, Philip M. The 2007-2012 World Outlook for Air Conditioning-And Refrigeration-Type Central System Standard Steam and Steam Distributing Tube Finned Coils. ICON Group International, Inc., 2006.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Coiled tubes"

1

Gnielinski, Volker. "G3 Heat Transfer in Helically Coiled Tubes." In VDI Heat Atlas, 709–12. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-540-77877-6_36.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Bhuvaneswari, S., and G. Elatharasan. "Numerical Study of Heat Transfer and Pressure Drop in a Helically Coiled Tubes." In Lecture Notes in Mechanical Engineering, 785–96. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-4488-0_66.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Ali, Nazim, and Monisha Mridha Mandal. "Immiscible Liquid-Liquid Flow in Coiled Tube." In Intelligent Computing Applications for Sustainable Real-World Systems, 307–19. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44758-8_28.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Fsadni, A. M., J. P. M. Whitty, A. A. Adeniyi, J. Simo, and H. L. Brooks. "A Review on the Application of Nanofluids in Coiled Tube Heat Exchangers." In Micro and Nanomanufacturing Volume II, 443–65. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-67132-1_15.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Frolov, S. M., I. V. Semenov, I. F. Ahmedyanov, and V. V. Markov. "Shock-to-detonation transition in tube coils." In Shock Waves, 365–70. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-85168-4_58.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Shinde, Amol D., and Amarsingh B. Kanase-Patil. "Investigation of Tube in Tube Helical Coil Heat Exchanger with Different Inner Tube Configuration." In Techno-Societal 2020, 457–66. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69925-3_45.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Saravana Bhavan, P., and J. Selwin Rajadurai. "Investigation on Helical Coiled Tube Heat Exchanger for Parallel and Counter Flow Using CFD Analysis." In Lecture Notes in Mechanical Engineering, 571–88. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-3631-1_56.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Kumar, Sanyog, and A. R. Jaurker. "Thermal Performance Analysis of Eccentric Helical Coil Tube in Tube Heat Exchanger Using CFD." In Lecture Notes in Mechanical Engineering, 143–55. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2921-4_14.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Kadam, Nilesh K., and A. R. Acharya. "Experimental Investigation of Helical Coil Tube in Tube Heat Exchanger with Microfins Using Al2O3/Water Nano Fluid." In Lecture Notes in Mechanical Engineering, 855–71. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5463-6_76.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Kumar, Ravi, Anil Kumar Patil, and Manoj Kumar. "Thermal Performance of Multiple Tube Sensible Energy Storage with Coil Inserts." In Green Energy and Technology, 61–66. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2279-6_6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Coiled tubes"

1

Conte´, Ibrahima, Xiao-Feng Peng, and Zhen Yang. "Numerical Investigations of Forced Convection From Rectangular Coiled Pipes." In 2007 First International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2007. http://dx.doi.org/10.1115/mnc2007-21136.

Full text

Abstract:

Investigations are done to numerically study forced convective heat transfer from the flow inside a rectangular coiled pipe, as micro-scale heat exchange device with staggered arrangement, to the external flow around the pipe. The commercial CFD software Fluent 6.0 is used as the solver. The problems considered were three-dimensional laminar flow of the refrigerant R141B through the tube and turbulent air flow exterior to the tube. The studied coiled pipe was composed of four rows among which two rows were encompassed in a large rectangular coil and the other two were in an inner smaller rectangular coil. The results showed remarkable differences in the flow behavior and heat transfer for different rows of tubes. The secondary flow in the tubes bends of the larger rectangular coil is very weak compared to that of the inner rectangular coil. Better heat transfer process occurred through the tubes of the second row where the higher values of the fluid temperatures were observed in the pipe. The results showed the effects of the straight tubes inclination angle on the flow behavior in rectangular coiled pipes. The shape of the secondary flow is changed from a couple of vortices in the case of smaller angle (α = 9°) to a single vortex in the case of larger angle (α = 45°). The results also showed the rotation of the maximum axial velocity due to the increase in the straight tubes inclination angles. The results are in good agreement with previous numerical and experimental works on laminar flow in helical coil pipe.

APA, Harvard, Vancouver, ISO, and other styles

2

Lagat, Christopher, Reem Roufail, Vamegh Rasouli, Brian Evans, and Soren Soe. "Experimental Investigation of Steel Coiled Tubes Performance Under Cyclic Bending." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23208.

Full text

Abstract:

Research is currently being undertaken in Australia to develop new drilling technologies for deep mineral exploration. The Deep Exploration Technologies Cooperative Research Centre (DET CRC) has carried out a comprehensive review of the available drilling technologies in the market. Following the study, coiled tube drilling technology has been suggested as a faster and cheaper method than conventional pipe drilling. This is primarily due to its smaller footprint relative to the standard rotary method, ease of unit mobility, less operating personnel, faster rate of penetration, and faster rig up and rig down times. The steel coiled tubing technology has traditionally been used in the petroleum industry. While there have been several attempts to evaluate the performance of coiled tubes in the oil and gas industry, limited or no attempts have been made to assess its performance in deep hard rock mineral exploration drilling. Therefore, DET CRC is in the process of re-designing the coiled tube rig approach to enable fast and efficient drilling of deep micro-holes in hard rocks. Cyclic bending of the coiled tubing past the yield strength point of the material leads to progressive weakening of the tube, which accordingly leads to rapid reduction of the tube service life [1]. Hence fatigue is an important parameter that needs to be considered in material selection for coiled tube and rig design. A bending machine was designed and manufactured to evaluate the fatigue bending strength of conventional HSLA steel tubes. The machine is capable of measuring and recording the bending/flattening resistant forces of the tubes along with the number of bend/flatten events. It can also measure the strain applied on the tube if needed. In this study, several HSLA steel grades and thicknesses of coiled tubes were tested for fatigue bending strength. Fatigued and non-fatigued tubes had their mechanical property alteration tested using tensile test methods. This paper presents the fatigue bending machine. The machine is designed to test most material types of coiled tubes. The paper also reports results of the cyclic bending experiments that were performed on selected grades and sizes of conventional HSLA steel coiled tubes. The paper complements and enhances the understanding of the performance of conventional coiled tube material under fatigue bending conditions.

APA, Harvard, Vancouver, ISO, and other styles

3

Zhu, Guangyu, and Hongye Zhu. "Numerical Simulation of Interfacial Phenomenon of Air-Water Adiabatic Intermittent Flow in Helically Coiled Tubes." In 2016 24th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icone24-60221.

Full text

Abstract:

Helically coiled tube are widely used as the basic heat transfer elements in steam generators of the next generation reactors, such as HTR-PM (High Temperature Gas-cooled Reactor), IRIS (International Reactor Innovative and Secure) and SMART (System-integrated Modular Advanced Reactor), because of the advantages in reducing space, enhancing heat transfer, accommodating thermal stress and preventing two-phase flow instabilities. Owing to the presence of gravity and centrifugal force that being perpendicular to the main flow, two-phase flow in helically coiled tubes has different features with either vertical flow or horizontal flow. To ensure safety and reliability of the plant, it is necessary to carry out detail investigation on the two-phase flow phenomena and mechanisms in helically coiled tubes. However, less research has been carried out on this subject than on straight tubes. In this work, the upward air-water slug and plug flows in helically coiled tubes have been numerically analyzed based on the computational fluid dynamics (CFD) techniques. Three dimension models of helically coiled tubes with inner diameter of 16 mm, coil diameter of 0.1 and 0.4m, pitch of 0.08 and 0.16m are constructed, for which the structural meshes are generated by software ANSYS ICEM. The gas-liquid interface is captured by the volume of fluid (VOF) approach adopting geo-reconstruction scheme for interface interpolation, which is solved by a pressure-based transient solver in the commercial CFD software ANSYS FLUENT 14.5. Bubble chord length, slug/plug frequency, bubble velocity and void fraction under different superficial velocities have been investigated. The numerical results meet well with the pictures recorded by a high speed camera. It is revealed that in slug regime, the bubbles mainly migrate towards the top and inner wall of the tube due to the combined action of gravity and centrifugal force, leading to a highly asymmetrical internal phase distributions. Meanwhile, the secondary flow in the cross section introduced by the centrifugal force enhances the turbulence and prevents small bubbles to coalescent into enlarged bubbles. Accordingly the intermittent flow regime in helically coiled tubes is narrower than that in straight horizontal tubes. Furthermore, the influences of geometrical parameters on phase distribution characteristics are predicted. The results show that the bubble length will increase along with the increase of the coil diameter or the pitch of the helically coiled tube. And the bubble frequency will increase with the decreasing of the tube coil diameter.

APA, Harvard, Vancouver, ISO, and other styles

4

Ghobadi, M., and Y. S. Muzychka. "Pressure Drop in Mini-Scale Coiled Tubing." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63348.

Full text

Abstract:

In the present study, laminar, steady state flow in mini-scale coiled tubes was studied experimentally. Three different tube diameters: 1.6 mm, 1.27 mm and 1.016 mm with different lengths of 1 m and 0.5 m were coiled with different radius of curvature to provide data over a wide range of Reynolds numbers from 5 to 2300. A simple empirical model is developed based on the experimental results to predict the pressure drop increase based on Dean number. The results and simple model are also compared to a well-known existing model for circular tubing. The coiled tube lengths used in this study were long enough to consider the flow to be fully developed. The effects of varying curvature and tube length are also studied. The pitch of the coils is restricted to the diameter of the tube to minimize the effect of coiling. Dean number is used instead of Coiled number (modified Dean number) which allows the results to be expanded to spiral and curved tubing.

APA, Harvard, Vancouver, ISO, and other styles

5

Chen, Chang-Nian, Ji-Tian Han, Li Shao, Tien-Chien Jen, and Yi-Hsin Yen. "Design of Equipment for Manufacturing Helically-Coiled Tubes and its Automatic Control System." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37146.

Full text

Abstract:

A simple but accurate method for manufacturing helically-coiled tubes was proposed, and the manufacturing equipment and its automatic control system were designed. The main geometric parameters of helically-coiled tubes are determined exactly based on the theorem “three given points determine a circle” and the definition of the helix angle of helically-coiled tubes. The finished equipment primarily consists of the mechanical noumenon and the automatic control system. In this design, three die wheels A, B and C made of wearable steel are used to adjust the positions of the raw materials in order to determine the product geometric parameters expected in advance. Three servo motors working with precision linear sliding rheostat and PID closed-loop control functions drive the three wheels mentioned above in different directions. The parameter e determining the base circle diameter of coil diameter is obtained by adjusting the position of wheel C up and down, and the parameter e’ determining the helix angle is obtained by adjusting the relative distance between wheel B and wheel A in the helical axis direction. The whole manufacture process is automatically controlled by a piece of software compiled by Visual Basic, including the processes of baiting and cutting, installing wheels and calibration, motor controlling, bending tubes, and product inspection etc. The design parameters for manufacturing helically-coiled tubes using SUS304 stainless steel or other similar materials are tube diameters of 6–50 mm, coil diameters of 100–700 mm and helical pitches of 10–50 mm. A total of fourteen finished products were selected as random samples for inspection. The result showed that the average working velocity was about 0.6 m/min; the root mean square errors (RMSE) of coil diameter and helical pitch of finished products were 3.85 mm and 0.97 mm, respectively; and the maximum roundness error of tubes was only 0.09 mm.

APA, Harvard, Vancouver, ISO, and other styles

6

Adrugi, W., Y. S. Muzychka, and K. Pope. "Pressure Drop of Liquid-Liquid Taylor Flow in Mini-Scale Coiled and Curved Tubing." In ASME 2019 17th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/icnmm2019-4219.

Full text

Abstract:

Abstract This paper presents an experimental study on pressure drop using non-boiling liquid-liquid Taylor flow in mini scale coiled and curved tubing. Experiments were carried out to measure the pressure drop characteristics by varying the numbers of turns in coiled tubes and the lengths of curved tubes of less than one turn, such that Dean number, Reynolds number, radius of curvature, and coil pitch were considered. A set of narrow coiled tubes (ID = 1.59 mm, 1.27 mm, 1.016 mm) was used as test sections with different radii of curvature and overall lengths, and thus a different quantity of turns. Water and 1 cSt low viscosity silicone oil were used to create a segmented slug flow. An asymptotic model is developed based on the experimental results and previous models to predict the pressure drop, based on Dean number and dimensionless slug length. The effects of varying tube curvature and tube diameter are also studied. The results provide new insights into the effect of coiling and secondary flow on pressure drop for a liquid-liquid Taylor flow in mini scale systems.

APA, Harvard, Vancouver, ISO, and other styles

7

Ishikawa, Masa-aki, Hiroshi Oiwa, Kosuke Sakai, Yuichi Murai, Shin-ichi Toda, Kiyoshi Tamayama, and Fujio Yamamoto. "Flow Structure and Pressure Loss of Two-Phase Flow in Helically Coiled Tubes." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45376.

Full text

Abstract:

In the steam generator of the prototype FBR (Fast Breeder Reactor) in Japan, heat exchange tubes of helical coil type are utilized. The gas-liquid two-phase flows in the helical coil tube have different characteristic from straight tubes due to the effects of centrifugal acceleration in the curved tubes. In our study, the interfacial structure of the gas-liquid two-phase flows in the helical coil tube is visualized to provide the flow pattern map. Simultaneously, the pressure loss and its local fluctuation are measured in order to investigate the dynamic characteristics of the two-phase flow appearing in the helical coil tube. The result reveals that the bubbly flow regime extends and the stratified flow vanishes compared the gas-liquid flow in a horizontal straight tube. Moreover, the slug flow has asymmetric structure due to the effect of centrifugal acceleration. On the contrary the pressure loss is basically not remarkably different from the straight tube except the fact that the pressure has a high fluctuation component.

APA, Harvard, Vancouver, ISO, and other styles

8

Gnielinski, Volker. "HEAT TRANSFER AND PRESSURE DROP IN HELICALLY COILED TUBES." In International Heat Transfer Conference 8. Connecticut: Begellhouse, 1986. http://dx.doi.org/10.1615/ihtc8.1360.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Chen, Chang-Nian, Ji-Tian Han, Li Shao, Wen-Wen Chen, and Tien-Chien Jen. "Experimental Study on CHF Characteristics of R134a Flow Boiling in Horizontal Helically-Coiled Tubes." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22579.

Full text

Abstract:

An experimental study of critical heat flux (CHF) was performed to investigate the CHF characteristics of R134a flow boiling in horizontal helically-coiled tubes. The test sections made of stainless steel were directly heated by high-power DC power sources to maintain constant heat-fluxes. The experimental parameters are the outlet pressures of 0.30–1.10 MPa, mass fluxes of 60–480 kg/m2s, inlet qualities of −0.32–0.36 and heat fluxes of 6–90 kW/2m. Thirteen helically-coiled tubes were tested with the outer diameters of 6–14 mm, inner diameters of 3.8–11 mm, coil diameters of 135–370 mm, helical pitches of 40–105 mm and valid heated lengths of 0.85–7.54 m. The detection for CHF occurrence was based on the event-driven method of Agilent BenchLink Data Logger Pro with a total of thirty-two 0.2mm T-type thermocouples set in every coil to measure the wall temperatures accurately. It was found that the wall temperatures jumped abruptly once the CHF occurred. The magnitude of CHF decreases with increasing valid heated length, coil diameter and inner diameter to some extent, while the DNB (departure from nucleate boiling) CHF seems independent when length-to-diameter L/di>200. Coil-to-diameter ratio is considered more important for CHF than length-to-diameter ratio in helically coiled tubes. The helical pitch has little effect on CHF. While CHF value increases much with increasing mass flux and decreases little with increasing absolute pressure, it decreases nearly linearly with increasing inlet qualities and critical qualities in different levels. But the CHF values at xcr<0.5 vary acutely than those at higher critical qualities. New experimental correlations for the DNB and the dry-out CHF of R134a flow boiling in horizontal helically-coiled tubes were developed.

APA, Harvard, Vancouver, ISO, and other styles

10

Kaew-On, Jatuporn, Santiphap Nakkaew, and Somchai Wongwises. "Single-Phase Heat Transfer in the Straight and Helically Coiled Tubes." In ASME 2013 11th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icnmm2013-73109.

Full text

Abstract:

In the present work, the single-phase heat transfer of water flowing through the straight and helical minichannel tubes was experimentally studied. The test section was made from the stainless tube with an internal diameter of 1.75mm and 70 cm long. The coil diameters were 34, 48, and 61 mm. The single-phase heat transfer is experimentally determined based on the direct heating operation. The experiments have been carried out by varying the water flow rates and supplying heat fluxes. The Reynolds numbers were performed covering the transition to turbulent flow regimes, while supplying the heat fluxes were approximately 30–70 kW/m2. The experimental results were compared with the existing correlations from the literature. The result illustrates that more enhanced heat transfer increase for tubes with greater curvature ratio.

APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Coiled tubes"

1

Villamil, Julie, Caique Lara, Anthony Abrahao, Aparna Arvelli, Guilherme Daldegan, Sharif Sarker, and Dwayne McDaniel. Development of a Pipe Crawler Inspection Tool for Fossil Energy Power Plants. Florida International University, October 2021. http://dx.doi.org/10.25148/mmeurs.009772.

Full text

Abstract:

Fossil fuel power plants are complex systems containing multiple components that create extreme environments for the purpose of extracting usable energy. Failures in the system can lead to increased down time for the plant, reduction of power and significant cost for repairs. In the past, inspections and maintenance of the plant's superheater tubes has been predominantly manual, laborious, and extremely time consuming. This is due to the pipe's small diameter size (between 1.3 and 7.6 cm) and the coiled structure of the tubing. In addition, the tubes are often stacked close to each other, limiting access for external inspection. Detection of pipe degradation, such as increased levels of corrosion, creep, and the formation of micro-cracks is possible using standard non-destructive evaluation (NDE) methods, including ultrasonic, radiography and electromagnetic methods. However, when the access to the sub-systems is limited or the configuration of the structure is prohibitive, alternative methods are needed for deploying the NDE tools. This research effort considers a novel robotic inspection system for the evaluation of small pipes found in typical boiler superheaters that have limited access. The pipe crawler system is an internal inspection device that can potentially navigate through the entire pipe length using linear actuators to grip the walls and inch along the pipe. The modular nature of the system allows it to traverse through straight sections and multiple 90-degree and 180-degree bends. The crawler is also capable of providing visual inspections, ultrasonic thickness measurements, and generating inner diameter surface maps using LiDAR (light detection and ranging). Ultimately, the development of this robotic inspection tool can provide information regarding the structural integrity of key pipeline components in fossil fuel power plants that are not easily accessible

APA, Harvard, Vancouver, ISO, and other styles

2

Peterson, Per F. Coiled Tube Gas Heaters For Nuclear Gas-Brayton Power Conversion. Office of Scientific and Technical Information (OSTI), March 2018. http://dx.doi.org/10.2172/1434471.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Lee S. Y. BETATRON TUNES and the CURRENT in the QUADRUPOLE TRIM COIL. Office of Scientific and Technical Information (OSTI), June 1990. http://dx.doi.org/10.2172/1150547.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Blanchard, A. Relocation Impacts of an H-Separations Coil and Tube Failure. Office of Scientific and Technical Information (OSTI), August 1999. http://dx.doi.org/10.2172/9557.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Blanchard, A. Relocation impacts of an H-Separations coil and tube failure. Office of Scientific and Technical Information (OSTI), March 2000. http://dx.doi.org/10.2172/752132.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Blanchard, A. Ingestion Pathway Consequences of an H-Separations Coil and Tube Failure. Office of Scientific and Technical Information (OSTI), August 1999. http://dx.doi.org/10.2172/9556.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Sagaiyaraj, Bernard. Increasing Energy Efficiency of Central Cooling Systems with Engineered Nanofluids. Department of the Built Environment, 2023. http://dx.doi.org/10.54337/aau538344493.

Full text

Abstract:

Buildings consume about 40% of the world’s energy consumption and of that, 65% is dedicated to cooling (or heating) systems. Central building cooling uses water as the main heat transfer medium. The nanoparticle fluid suspension exhibits thermal properties superior to water. The goal was to achieve the highest possible thermal properties with just the right amount of nanoparticles in a uniform and stable dispersion and suspension in water. This engineered nanofluid contains a uniform and stable suspension of graphene nanoparticles (GNP) in water. Using covalent functionalization, centrifugation and high-speed dispersion, the GNP remains in a stable suspension indefinitely. The nanofluid is applied to the closed loop of the chilled water system, where the heat transfer enhancement occurs at the fluid tubes within the evaporator and the tubing in the chilled water coils within the Air Handling Units(AHUs). The Proof of Concept (POC) completed in 2019 using laboratory-derived nanofluid resulted in energy saving that averaged at 32% compared with the baseline fluid (water). In 2022, a Scaled-Up mini plant produced GNP nanofluids in a commercial process environment, showing an average energy savings of 21%. These results were further verified and validated on small chilled water plants outside of the Scaled-Up plant with 25% and 29% average savings.

APA, Harvard, Vancouver, ISO, and other styles

8

Richard A. Corbett and Dave Severance. DEVELOPMENT OF A REPRODUCIBLE SCREENING METHOD TO DETERMINE THE MECHANISM AND EFFECT OF ORGANIC ACIDS AND OTHER CONTAMINANTS ON THE CORROSION OF ALUMINUM-FINNED COPPER-TUBE HEAT EXCHANGE COILS. Office of Scientific and Technical Information (OSTI), February 2005. http://dx.doi.org/10.2172/877662.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Nikolaev, Valeri. Study of the Process of Mixing, Temperature, and Small Signal Gain in the Active Medium of Supersonic COIL With Advanced Nozzle Bank and DC Discharge Method of O2(1 Delta) Production in a Vortex Tube. Fort Belvoir, VA: Defense Technical Information Center, July 2001. http://dx.doi.org/10.21236/ada389462.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!