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1
Sun, Lin, Biwei Fu, Menghui Wei, and Si Zhang. "Analysis of Enhanced Heat Transfer Characteristics of Coaxial Borehole Heat Exchanger." Processes 10, no. 10 (October 12, 2022): 2057. http://dx.doi.org/10.3390/pr10102057.
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Coaxial borehole heat exchangers provide a practical method for geothermal energy extraction, but heat transfer efficiency is low. In order to address this problem, three coaxial borehole heat exchangers with vortex generators, based on the enhanced heat transfer theory, are proposed in this paper. The author compared and analyzed the heat transfer performance of three coaxial borehole heat exchangers with vortex generators and those of traditional structures, which explains why the new heat exchanger’s heat transfer mechanism is enhanced. The results demonstrated that the vortex generator can enhance the fluid flow’s turbulent kinetic energy in the coaxial heat exchanger. This generator can also improve the mixing characteristics of the fluid flow and heat transfer. The resultant increase in the inlet flow velocity can decrease the friction coefficient f, increase the Nusselt number and strengthen the coaxial sleeve. As a result, the heat exchange performance of the tubular heat exchanger will also be improved. The thread vortex generator (TVG) heat exchanger outperforms the other three heat exchangers in terms of heat exchange performance, extraction temperature and heat extraction power. The results evidenced that the TVG heat exchanger is better than the smooth tube heat exchanger. The thermal performance coefficient PEC was improved by 1.1 times, and the extraction temperature and heating power were increased by 24.06% and 11.93%, respectively. A solid theoretical foundation is provided by the extracted outcomes for designing and selecting high-efficiency coaxial borehole heat exchangers suitable for geothermal energy extraction.
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Daheriya, Sharad Kumar. "Comparative Experimental Study and Performance Intensification of Heat Exchanger by 55° Corrugated Tube and Twisted Tape Inserts of Pitch Length 1.5." International Journal for Research in Applied Science and Engineering Technology 13, no. 4 (April 30, 2025): 1182–93. https://doi.org/10.22214/ijraset.2025.68399.
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The principal objective of this comparative experimental analysis is to determine the straight 55° corrugated steel tube heat exchanger is more beneficial to utilize than a standard straight steel tube heat exchanger. Straight tubes make heat exchanger tube fabrication easier. As a result, helical tubes and numerous other smaller tube forms of heat exchangers are inferior to straight tube heat exchangers. Most research on heat transfer coefficients is done for constant heat flow or constant wall temperature, while more recent work considers fluid-to-fluid heat exchange. In parallel flow and counter flow arrangements of straight plain steel tube, straight 55° corrugated steel tube, straight steel tube with insert heat exchangers, and straight 55° corrugated steel tube with insert, the effectiveness, overall heat transfer coefficient, effect of hot water flow rate on effectiveness when cold water flow rate kept constant were studied and compared. At the heat exchanger's steady state, all measurements were made. The outcome is displayed graphically for the two tubes' respective efficaciousness under various flow configurations. When the cold-water flow is fixed at 45 lph and the hot water mass flow rate fluctuates at 15,30,45,60, and 75 lph the heat exchanger's effectiveness drops up to 45 lph and increases up to 75 lph for both straight steel and corrugated tube heat exchangers; the straight steel tube heat exchanger's effectiveness is better than the other tube heat exchangers. On the other hand, the heat transfer rate of the heat exchanger steadily increases when the mass flow rate of the hot water is varied and the cold water remains constant.
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Shaimerdenova, К. М., E. R. Schrager, A. S. Tussypbaeva, and Zh K. Nausharban. "Investigation of heat exchange processes in vertically arranged heat exchangers." Bulletin of the Karaganda University. "Physics" Series 94, no. 2 (June 28, 2019): 66–72. http://dx.doi.org/10.31489/2019ph2/66-72.
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Balaji, Viswanadhapalli, Sridhar Padala, Sanjeev Kumar Josh, Muntadar Muhsen, Satyendra Singh, Baxtjon Isroilova, and Dildora Israilova. "Finite element analysis of double pipe heat exchanger using nanofluids." E3S Web of Conferences 563 (2024): 01004. http://dx.doi.org/10.1051/e3sconf/202456301004.
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Heat exchangers are now a necessary part of practically all contemporary industries. Heat exchangers have become especially important in an era of scarce resources and fierce market rivalry. In order to study a counterflow heat exchanger's thermal performance, this work modifies the compositions of the coolant and nanofluid that contain iron particles. To evaluate the efficacy of heat exchangers, analysis findings including heat transfer rates, total heat transfer coefficients, and heat exchanger effectiveness have been computed. This project's goal is to ascertain whether using nanofluids enhances heat exchanger performance.
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Walsh, Christian, Rana Ronak, Rathod Hiren, Patel Dhiraj, and Patel Atul. "A Case Study on Basic of Heat Exchanger." Research and Applications of Thermal Engineering 6, no. 3 (December 9, 2023): 31–36. https://doi.org/10.5281/zenodo.10319184.
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<i>Equipment that exchanges or transfers heat energy for various uses is called a heat exchanger. Heat exchangers are essential in the industrial sector because they recover heat between two process fluids. The most popular heat transfer devices are plate heat exchangers, shell and tube heat exchangers, and concentric tube (double pipe).The study of fluid flow and heat conduction by computer numerical calculation and graphical display is known as computational fluid dynamics, or CFD. The fundamental design techniques for two fluid heat exchangers are covered in this chapter.</i>
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Ge, Yu Lin, Ping Wang, Sheng Qiang Shen, and Jun Liang Xu. "Synthesis Method of Heat Exchanger Network for Distillation Device." Advanced Materials Research 199-200 (February 2011): 1509–12. http://dx.doi.org/10.4028/www.scientific.net/amr.199-200.1509.
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Mathematical programming model for synthesis of heat exchanger network for distillation unit is established. MINLP problem for heat exchanger network is solved by branch-bound method. Two kinds of heat exchanger network with splitting stream and without splitting stream are obtained. 142 heat exchangers, 8 coolers and 4 heaters are needed in the heat exchanger network without splitting stream. 34 heat exchangers, 8 coolers, 4 heaters, 11 splitters and 11 mixers are needed in the heat exchanger network with splitting stream. The matching situation including heat load, heat exchange area, duty of utilities, flow fraction of splitting, temperature of inlet and outlet, etc. for cold and hot streams in the heat exchanger network with splitting stream is presented in detail, Analysis the relationship between total heat exchange area, total heat load, total capital cost and annual operation cost of the heat exchanger network. Taking the number of heat exchangers and operational flexibility of heat exchange network into consideration, the heat exchanger network with splitting stream is suggested to be selected.
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Rydalina, Natalia, Oleg Stepanov, and Elena Antonova. "The use of porous metals in the design of heat exchangers to increase the intensity of heat exchange." E3S Web of Conferences 178 (2020): 01026. http://dx.doi.org/10.1051/e3sconf/202017801026.
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Heat exchangers are widely used in heat supply systems. To increase the efficiency of heat supply systems, heat exchangers with porous metals are proposed to design. There was a test facility set up to study new types of heat exchangers. The countercurrent flow of heat carriers was activated in those heat exchangers. Freon moved through the heat exchanger pores, and water moved through the inner tubes. It should be noted that the porous materials in the heat exchangers differed in the coefficient of porosity. To be compared, one of the heat exchangers did not contain any porous material. The first test cycle proved the feasibility of using porous metals in heat exchange equipment. Afterwards, a simplified mathematical model of the heat exchanger was compiled. Such an analytical form makes a solution convenient for engineering calculations. Numerical calculations based on this model were compared with the experimental data. Heat transfer intensity of materials with different porosity was compared.
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Wang, Geng, Nai Rong, Xuefei Li, Ning Hu, Zhi Zhang, Yuan Zhang, and Yuhan Wang. "Coaxial Pipes Used as Ground Buried Heat Exchangers—A Review of Research in Recent Years." Buildings 15, no. 2 (January 15, 2025): 243. https://doi.org/10.3390/buildings15020243.
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The efficient utilization of geothermal energy depends heavily on high-performance ground heat exchangers. Coaxial pipe is a high-efficiency heat exchanger composed of two nested tubes of different diameters. In this paper, the structure and thermal exchange characteristics of coaxial pipe geothermal exchangers are introduced, which are superior to single-U and double-U geothermal exchangers in respect of installation, heat transporting, and deep geothermal application. Thermal test research of coaxial pipe geothermal exchangers is investigated. Relevant studies in recent years on the factors affecting the thermal performance of coaxial pipe ground heat exchangers, including exchanger configurations, circulating fluids, subsurface conditions, flow patterns, and operational modes, are reviewed. In addition, research on the impact of coaxial pipe ground heat exchangers on the ground, as well as applications for coaxial pipe ground heat exchangers, is summarized. Recommendations are made for potential future research on coaxial pipe ground heat exchangers. It is believed that the results of these studies will help to raise awareness of coaxial pipe ground heat exchangers and to continue to promote their application.
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Rostami, Mohammadreza Hasandust, Gholamhassan Najafi, Ali Motevalli, Nor Azwadi Che Sidik, and Muhammad Arif Harun. "Evaluation and Improvement of Thermal Energy of Heat Exchangers with SWCNT, GQD Nanoparticles and PCM (RT82)." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 79, no. 1 (December 31, 2020): 153–68. http://dx.doi.org/10.37934/arfmts.79.1.153168.
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Today, due to the reduction of energy resources in the world and its pollutants, energy storage methods and increase the thermal efficiency of various systems are very important. In this research, the thermal efficiency and energy storage of two heat exchangers have been investigated in series using phase change materials (RT82) and single wall carbon nanotubes (SWCNT) and graphene quantum dot nanoparticles (GQD) In this research, two heat exchangers have been used in combination. The first heat exchanger was in charge of storing thermal energy and the second heat exchanger was in charge of heat exchange. The reason for this is to improve the heat exchange of the main exchanger (shell and tube) by using heat storage in the secondary exchanger, which has not been addressed in previous research. The results of this study showed that using two heat exchangers in series, the thermal efficiency of the system has increased. Also, the heat energy storage of the double tube heat exchanger was obtained using phase change materials in the single-walled carbon nanotube composition of about 3000 W. The average thermal efficiency of the two heat exchangers as the series has increased by 52%. In general, the effect of the two heat exchangers on each other was investigated in series with two approaches (energy storage and energy conversion) using fin and nanoparticles, which obtained convincing results.
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Manoj, Kumar, and Kumar Sinha Abhimanyu. "HEAT EXCHANGER DESIGN: ABC ALGORITHM." International Journal For Technological Research In Engineering 9, no. 11 (July 23, 2022): 23–25. https://doi.org/10.5281/zenodo.6889553.
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The most prevalent heat exchange equipment is shell-and-tube heat exchangers. Shell and tube heat exchangers, despite technological developments in other exchanger types, hold a major place in industrial applications due to their wide range of operating conditions, resilience, versatility, and reliability. Because heat exchangers are widely used in industrial processes, lowering their costs is a priority for both designers and users. A generalized approach for shell and tube heat exchanger design has been developed and presented in this paper to predict surface area, overall heat transfer coefficient, pressure drop/pumping power for known input values of heat duty, tube layout, tube outside diameter, baffle spacing, shell diameter, and thermo-physical property of working substance for known input values of heat duty, tube outside diameter, baffle spacing, shell diameter, and thermo physical property of working substance.
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Zhang, Zhou Wei, Ya Hong Wang, and Jia Xing Xue. "Research and Develop on Series of Cryogenic Liquid Nitrogen Coil-Wound Heat Exchanger." Advanced Materials Research 1070-1072 (December 2014): 1817–22. http://dx.doi.org/10.4028/www.scientific.net/amr.1070-1072.1817.
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The research and development situation of liquid nitrogen coil-wound heat exchanger were discussed in view of heat exchange in gas purification field in petrol-chemical industry. The basic designing methods and the multi-stream heat exchange process were illustrated by the cryogenic and high pressure crossing heat exchange equipments of liquid nitrogen coil-wound heat exchanger with multi-stream and multiphase flow, including Three-stream back-cooling heat exchangerin first stage, Four-stream back-cooling heat exchangerin second stage, Five-stream back-cooling heat exchangerin third stage, Multi-stream main back-coolingcoil-wound heat exchanger etc. A series of coil-wound heat exchangers with different mixed fluids and different applications were described. The winding structure characteristics and the work principles of the spiral pipe bundles were elaborated to give references for the scientific design and calculation of coil-wound heat exchanger in cryogenic field. The important research directions and the critical scientific problems were forecasted.
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Lee, Seung-Rae. "Evaluation of Heat Exchange Rate of Different Types of Ground Heat Exchangers." Journal of the Korean Society of Civil Engineers 33, no. 6 (2013): 2393. http://dx.doi.org/10.12652/ksce.2013.33.6.2393.
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Rydalina, N. V., B. G. Aksenov, O. A. Stepanov, and E. O. Antonova. "Application of porous materials in heat exchangers of heat supply system." Power engineering: research, equipment, technology 22, no. 3 (September 8, 2020): 3–13. http://dx.doi.org/10.30724/1998-9903-2020-22-3-3-13.
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Heat exchange capacity increase is one of the main concerns in the process of manufacturing modern heat exchange equipment. Constructing heat exchangers with porous metals is an advanced technique of heat exchange increase. A construction of heat exchangers with porous aluminum is described in this paper. The first heat transfer agent (hot water) flows through thin copper tubes installed within the porous aluminum. The second heat transfer agent (freon) flows through the pores of aluminum. Laboratory facility was created to study such a heat exchanger. Series of experiments were carried out. The purpose of the research presented here is to create a mathematical model of heat exchangers with porous metals, to perform analytical calculation of the heat exchangers and to confirm the results with the experimental data. In this case, one can`t use the standard methods of heat exchangers calculation because the pores inner surface area is indeterminate. The developed mathematical model is based on the equation describing the process of cooling the porous plate. A special mathematical technique is used to take into account the effect of tubes with water. The model is approximate but its solution is analytic. It is convenient. One can differentiate it or integrate it, which is very important. Comparison of calculated and experimental data is performed. Divergence of results is within the limits of experimental error. If freon volatilizes inside the heat exchanger, the heat of phase transition has to be taken into account alongside with heat capacity. The structure of the mathematical model makes it possible. The results presented in this paper prove the practicability of using porous materials in heat exchange equipment.
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Mikulionok, Іgor, Аnton Karvatskii, Olena Ivanenko, and Serhii Leleka. "Heat exchangers with fluidization of bulk material (Design review)." Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving, no. 3 (September 30, 2022): 23–38. http://dx.doi.org/10.20535/2617-9741.3.2022.265359.
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A classification of heat exchangers with fluidization of bulk material for use in enterprises of the chemical, mining, construction, food, metallurgical and processing industries has been developed. A critical review of the most characteristic designs of heat exchangers with a fluidized bed, proposed by scientists, designers and inventors of the leading countries of the world, has been carried out. The designs of heat exchangers are analyzed depending on the method of fluidization, the role of bulk material in the heat exchange process, the nature of the heat exchange process over time, the nature of fluidization (in continuous heat exchangers), the mechanism of heat exchange of bulk material, the number of fluidized beds, the presence of additional heat exchange devices in the heat exchanger, the presence of movable structural elements, as well as the type of bulk material of the fluidized bed.
 An analysis of the designs of heat exchangers with a fluidized bed indicates their considerable diversity, however, the most simple to manufacture and operate reliable devices with fixed structural elements and one fluidized bed remain in demand by the industry. The most promising direction for improving fluidized bed heat exchangers is the development of specialized (for processing bulk material or fluid coolant) designs of apparatuses.
 In the future, it is planned to analyze the designs of other types of heat exchangers, as well as ways to improve their efficiency.
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Zheng, Can, Fei Wang, and Yong Gang Lei. "Numerical Simulation of a Shell-and-Tube Heat Exchanger with Special Form Helical Baffles." Advanced Materials Research 860-863 (December 2013): 754–57. http://dx.doi.org/10.4028/www.scientific.net/amr.860-863.754.
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A new type of helical baffles heat exchanger is presented in this paper. Comparative study, through numerical simulation, was undertook between the new helical baffles heat exchanger and segmental baffle board heat exchanger in shell side flow and heat exchange characteristics. Fluid medium in the shell side is air. At the same velocity in the same flow conditions, pressure drop of helical baffles heat exchangers fell by an average of 26.8% compared with segmental baffle board heat exchangers, and the unit pressure drop of the heat transfer ratio of helical baffles heat exchanger increased by an average of 40.6%.
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Pandya, Bhavik J., and C. Karia Megha. "Latest Trends in Novel Applications of Various Heat Exchangers for Enhancement of Heat Transfer." Journal of Modern Thermodynamics in Mechanical System 1, no. 1 (July 16, 2019): 16–26. https://doi.org/10.5281/zenodo.3337408.
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A heat exchanger is equipment used for transfer of heat from one medium to other medium. Heat exchangers are fundamental parts in many process industries (such as power plants or the chemical and the food industries), and as heat recovery units in the operation of many systems (such as domestic hot water production, space heating or car engines).In a compact structure of cryogenic and other industrial applications for enhancement of heat transfer, coil heat exchangers are generally used. Currently, increase in efficiency of heat exchanger and heat transfer rate of heat exchanger, lots of researchers are working on it.
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Fakheri, Ahmad. "Heat Exchanger Efficiency." Journal of Heat Transfer 129, no. 9 (November 16, 2006): 1268–76. http://dx.doi.org/10.1115/1.2739620.
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This paper provides the solution to the problem of defining thermal efficiency for heat exchangers based on the second law of thermodynamics. It is shown that corresponding to each actual heat exchanger, there is an ideal heat exchanger that is a balanced counter-flow heat exchanger. The ideal heat exchanger has the same UA, the same arithmetic mean temperature difference, and the same cold to hot fluid inlet temperature ratio. The ideal heat exchanger’s heat capacity rates are equal to the minimum heat capacity rate of the actual heat exchanger. The ideal heat exchanger transfers the maximum amount of heat, equal to the product of UA and arithmetic mean temperature difference, and generates the minimum amount of entropy, making it the most efficient and least irreversible heat exchanger. The heat exchanger efficiency is defined as the ratio of the heat transferred in the actual heat exchanger to the heat that would be transferred in the ideal heat exchanger. The concept of heat exchanger efficiency provides a new way for the design and analysis of heat exchangers and heat exchanger networks.
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Chen, T. Y., H. P. Cho, C. S. Jwo, M. H. Hung, and W. S. Lee. "Analyzing How the ZrO2Far Infrared Material Affects the Performance of Smooth Tube Heat Exchangers." Journal of Nanomaterials 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/124632.
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The aim of this study was to investigate the effect of the 100 nm ZrO2far infrared material on the heat exchange efficiency of smooth tube heat exchangers. In the experiments designed for this purpose, the ZrO2powder and water based acrylic paint were mixed separately using a two-step mixing method and the mixture samples were sprayed, respectively, onto heat exchangers for testing their heat exchange efficiency under stable ambient conditions. Results from the experiments showed 31.8% and 21.5% increases in heat transfer in the heat exchanger sprayed with 7.5 wt.% ZrO2powder and with inlet water temperatures at 45°C and 55°C relative to the heat exchanger sprayed with 0 wt.% acrylic paint and 26.4% and 18.9% increases in heat transfer relative to the heat exchanger not sprayed with acrylic paint. The experiments also verified that heat could be transferred through radiation. The additive ZrO2nanopowder in these experiments is proven to be able to improve the efficiency of heat exchangers through radiation, thereby increasing the feasibility of its application in practice.
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Krutova, I. A., and Ya D. Zolotonosov. "Solution of the conjugate heat exchange problem for conical heat exchangers." Power engineering: research, equipment, technology 26, no. 6 (January 13, 2025): 214–26. https://doi.org/10.30724/1998-9903-2024-26-6-214-226.
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RELEVANCE The article is devoted to the development of new designs of heat exchangers and evaluating the efficiency of their operation. According to the authors, currently of particular interest are conical heat exchangers of the "pipe-in-pipe" type, so the object of research in this paper is a heat exchanger in the form of a truncated cone based on a spring-twisted channel. The introduction of the proposed heat exchange elements and apparatuses into the industry requires additional research. To assess the effectiveness of the application of the considered TA, it is proposed to evaluate its performance in comparison with conical and cylindrical TA based on a smooth-walled pipe. Due to this, two hypotheses will be tested at once: the use of a conical coil heat exchanger is more efficient than a cylindrical one, and the replacement of a smooth-walled pipe with a spring-twisted channel increases the efficiency of the heat exchanger.OBJECT. The aim of the research is to develop a method for setting and solving the conjugate heat exchange problem for a heat exchanger in the form of a truncated cone with a heat exchange element in the form of a spring-twisted channel, analyze the results obtained and evaluate the efficiency in comparison with conical and cylindrical heat exchangers based on smooth-walled heat exchange elements. METHODS. For the numerical solution of the conjugate heat transfer problem, the FEM implemented by means of Ansys was used Fluent. RESULTS. The main results consist in the fact that the authors developed a model and algorithm for calculating conical coil heat exchangers of the pipe-in-pipe type, implemented in the Ansys program, and determined the thermal and hydrodynamic parameters of coil devices. A comparison of coil heat exchangers was also made: a conical one based on a spring-twisted channel with a conical one and a cylindrical one with a smooth-walled heat exchange element. The calculation results showed that replacing a smooth-walled pipe with a spring-wound channel significantly increases the efficiency of heat exchange equipment. CONCLUSION. The significance of the obtained results lies in the possibility of using modern, more efficient and compact heat exchange equipment for technological needs and in the justification of this choice. Thus, with equal initial data, conical heat exchangers are more efficient than cylindrical ones with a heat exchange element in the form of a smooth tube, since they need a smaller heat exchange surface to achieve the necessary thermal and hydrodynamic parameters. The results of calculations prove the prospects of using a conical TA based on a spring-twisted channel and show the need for further study of the influence of the geometric characteristics of both the coil itself and the heat exchange element on the thermal and hydrodynamic characteristics of the proposed HE.
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Osipov, S. N., and A. V. Zakharenko. "Energy-Efficient Compact Heat Exchangers Made of Porous Heat-Conducting Materials." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 61, no. 4 (July 20, 2018): 346–58. http://dx.doi.org/10.21122/1029-7448-2018-61-4-346-358.
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After successful increase of levels of thermal resistances of building enclosing structures, expenses of heat on ventilation of rooms in many cases reached similar magnitudes of indicators of heating in a cold season. Therefore, the development of new efficient heat exchangersheat exchangers of small size is of particular importance. It is possible now to create highperformance thin (of a few centimeters) heat exchangers of such high-porous heat-conducting materials as copper, aluminum, etc. Highly porous materials include porous-permeable structures having an open porosity (with a total pore surface area of more than 50 % in relation to a smooth surface). One of the main conditions for the qualitative use of such high-porous thermal conductive materials is the rapid removal of condensate outside the heat exchange zone without a significant increase in filtration resistance. Thermal calculation of such heat exchangers is based on the criteria of Fourier (Fu) and Predvoditelev (Рd). Various ways of using high-porous heat-conducting materials in the design of heat exchangers are considered. The method of production of the heat exchanger based on the application of porous-permeable material in the channels of the heat exchange part of recuperative devices is presented; the difference of the method is that the heat exchange part is performed of two or more parallel heat exchange plates with spacing between them. It has been found that a significant increase in the energy efficiency of heat exchangers of this type is possible due to the application of even small discontinuities of the heat-conducting layers of high-porous materials so to use the specific features of increased heat exchange of the initial sections with the flowing fluid. One of the main advantages of using air-to-air heat exchangers made of foamed high-heat-conducting material in the climatic conditions of Belarus is freezing resistance.
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Haghshenas, Fard, Mohammad Talaie, and Somaye Nasr. "Numerical and experimental investigation of heat transfer of ZnO/Water nanofluid in the concentric tube and plate heat exchangers." Thermal Science 15, no. 1 (2011): 183–94. http://dx.doi.org/10.2298/tsci091103048h.
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The plate and concentric tube heat exchangers are tested by using the water-water and nanofluid-water streams. The ZnO/Water (0.5%v/v) nanofluid has been used as the hot stream. The heat transfer rate omitted of hot stream and overall heat transfer coefficients in both heat exchangers are measured as a function of hot and cold streams mass flow rates. The experimental results show that the heat transfer rate and heat transfer coefficients of the nanofluid in both of the heat exchangers is higher than that of the base liquid (i.e., water) and the efficiency of plate heat exchange is higher than concentric tube heat exchanger. In the plate heat exchanger the heat transfer coefficient of nanofluid at mcold = mhot = 10 gr/sec is about 20% higher than base fluid and under the same conditions in the concentric heat exchanger is 14% higher than base fluid. The heat transfer rate and heat transfer coefficients increases with increase in mass flow rates of hot and cold streams. Also the CFD1 code is used to simulate the performance of the mentioned heat exchangers. The CFD results are compared to the experimental data and showed good agreement. It is shown that the CFD is a reliable tool for investigation of heat transfer of nanofluids in the various heat exchangers.
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Sit, M.L., V.I. Patsiuk, A.A. Juravliov, V.I. Burciu, and D.V. Timchenko. "Control of Heat Exchangers with Variable Heat Transfer Surface Area." Problemele Energeticii Regionale 1 (39) (April 24, 2019): 90–101. https://doi.org/10.5281/zenodo.2650427.
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The work deals with the development of a control system for heat exchangers with variable surface area of heat transfer, used, in particular, for heat pumps intended primarily for heat supply systems using the high-quality law of regulation of the heat supply mode (with a constant flow rate of the heat carrier). The aim of the work is to develop a scheme for the control of a heat exchanger with a variable surface area of heat exchange in which main disturbances will be compensated: i.e. the temperature of the heat carrier, heat carrier’s flowrates, and changes in the thermophysical parameters of the heat carriers. This goal has been achieved using a custom PID controller in the contour of control of the drive of the moving heat-insulating insert. To solve this problem, we obtained the equations of the statics of the heat exchanger with regard to the adjustable insert, the dynamic model of the heat exchanger taking into account this insert. The novelty of the work is control laws of an adjustable heat-conducting insert between the primary and secondary coolants of the heat exchanger, which allow compensating the main disturbances, which influence the heat exchanger. A method has been developed for solving differential-integral equations of heat exchanger statics with an insert (HEI), which allowed analytically expressing the ratio of average integral heat carrier temperatures in a heat exchanger depending on the heat exchanger length, which allows building a control system for a heat exchanger with a variable heat exchange surface area.
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Ridwan, Iskandar, and Insannul Kamil. "Pengaruh Penambahan Sirip Longitudinal Terhadap Karakteristik Penukar Kalor Pipa Ganda." Jurnal Inovasi Rekayasa Mekanikal dan Termal 2, no. 1 (June 30, 2024): 29–35. https://doi.org/10.25077/inomet.1.1.29-35.2024.
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A heat exchanger is a device for exchanging energy in the form of heat between two or more fluids of different temperatures. There are several types of heat exchangers, including a double-pipe heat exchanger. This double-pipe heat exchanger is used widely in field practice. Double pipe heat exchangers are especially suited to standard thick surfaces in fins shape so that heat transfer is increased. The research is conducted to observe how far the use of fins in double-pipe heat exchange affects its characteristics. The fins added in the study are elongated fins on the outer surface of the inner pipe. The research is carried out using the working fluid water, with cold fluid in the heat exchanger annulus. From the research carried out, it can be said that heat transfer increases with the addition of fins, namely around 15%, but the pressure drop also increases, i.e., around 904 Pa (29%), compared to double pipe heat exchangers without fins. Research has also shown that the highest effectiveness of double pipe finned heat exchanger is 0.28, while without fins, it is 0.19.
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Ghorbani, M., and S. F. Ranjbar. "Optimization of Compressed Heat Exchanger Efficiency by Using Genetic Algorithm." International Journal of Applied Mechanics and Engineering 24, no. 2 (May 1, 2019): 461–72. http://dx.doi.org/10.2478/ijame-2019-0029.
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Abstract Due to the application of coil-shaped coils in a compressed gas flow exchanger and water pipe flow in airconditioner devices, air conditioning and refrigeration systems, both industrial and domestic, need to be optimized to improve exchange capacity of heat exchangers by reducing the pressure drop. Today, due to the reduction of fossil fuel resources and the importance of optimal use of resources, optimization of thermal, mechanical and electrical devices has gained particular importance. Compressed heat exchangers are the devices used in industries, especially oil and petrochemical ones, as well as in power plants. So, in this paper we try to optimize compressed heat exchangers. Variables of the functions or state-of-the-machine parameters are optimized in compressed heat exchangers to achieve maximum thermal efficiency. To do this, it is necessary to provide equations and functions of the compressed heat exchanger relative to the functional variables and then to formulate the parameter for the gas pressure drop of the gas flow through the blades and the heat exchange surface in relation to the heat duty. The heat transfer rate to the gas-side pressure drop is maximized by solving the binary equation system in the genetic algorithm. The results show that using optimization, the heat capacity and the efficiency of the heat exchanger improved by 15% and the pressure drop along the path significantly decreases.
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Sliwa, Tomasz, Aneta Sapińska-Śliwa, Andrzej Gonet, Tomasz Kowalski, and Anna Sojczyńska. "Geothermal Boreholes in Poland—Overview of the Current State of Knowledge." Energies 14, no. 11 (June 2, 2021): 3251. http://dx.doi.org/10.3390/en14113251.
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Geothermal energy can be useful after extraction from geothermal wells, borehole heat exchangers and/or natural sources. Types of geothermal boreholes are geothermal wells (for geothermal water production and injection) and borehole heat exchangers (for heat exchange with the ground without mass transfer). The purpose of geothermal production wells is to harvest the geothermal water present in the aquifer. They often involve a pumping chamber. Geothermal injection wells are used for injecting back the produced geothermal water into the aquifer, having harvested the energy contained within. The paper presents the parameters of geothermal boreholes in Poland (geothermal wells and borehole heat exchangers). The definitions of geothermal boreholes, geothermal wells and borehole heat exchangers were ordered. The dates of construction, depth, purposes, spatial orientation, materials used in the construction of geothermal boreholes for casing pipes, method of water production and type of closure for the boreholes are presented. Additionally, production boreholes are presented along with their efficiency and the temperature of produced water measured at the head. Borehole heat exchangers of different designs are presented in the paper. Only 19 boreholes were created at the Laboratory of Geoenergetics at the Faculty of Drilling, Oil and Gas, AGH University of Science and Technology in Krakow; however, it is a globally unique collection of borehole heat exchangers, each of which has a different design for identical geological conditions: heat exchanger pipe configuration, seal/filling and shank spacing are variable. Using these boreholes, the operating parameters for different designs are tested. The laboratory system is also used to provide heat and cold for two university buildings. Two coefficients, which separately characterize geothermal boreholes (wells and borehole heat exchangers) are described in the paper.
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Zhang, Yin, Yinping Zhang, and Xin Wang. "Inverse Problem Method to Optimize Cascade Heat Exchange Network in Central Heating System." International Journal of Energy Optimization and Engineering 9, no. 3 (July 2020): 62–82. http://dx.doi.org/10.4018/ijeoe.2020070105.
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In central heating systems, heat is often transferred from heat source to users by the heat network where several heat exchangers are installed at the heat source, substations, and terminals. In this article, the mathematical optimization model of the cascade heat exchange network with three-stage heat exchangers in a series is established. The aim is to maximize the cold fluid temperature for a given hot fluid temperature and overall heating capacity, the optimal heat exchange area distribution, and the medium fluid flow rates are determined through an inverse problem and variation method. The results show that the heat exchange areas should be distributed equally for each heat exchanger. It also indicates that in order to improve the thermal performance of the whole system, more heat exchange areas should be allocated to the heat exchanger where flow rate difference between two fluids is relatively small.
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Liu, Yongqi, Xiaoling Luo, Shichao Sun, and Dongmei Gao. "Research Progress and Application Prospect Of Microchannel Heat Exchangers." Advances in Computer and Engineering Technology Research 1, no. 4 (December 6, 2024): 24. https://doi.org/10.61935/acetr.4.1.2024.p24.
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A Micro-channel heat exchanger gradually replaces traditional heat exchanger with the advantages of high heat exchange efficiency, fast heating speed, good controllability, low noise, stable operation, good pressure bearing capacity and cost saving. The thesis summarizes the research progress and development prospects of the microchannel heat exchanger.Summarized and elaborated on the unparalleled advantages of microchannel heat exchangers compared to conventional sized equipment which is compared with the regular size equipment. Moreover application fields and prospects of the microchannel heat exchanger are analyzed from the point of energy saving and space occupancy．The thesis has some reference value for the research of micro heat exchangers.
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Azwinur, Azwinur, and Zulkifli Zulkifli. "KAJI EKSPERIMENTAL PENGARUH BAFFLE PADA ALAT PENUKAR PANAS ALIRAN SEARAH DALAM UPAYA OPTIMASI SISTEM PENGERING." SINTEK JURNAL: Jurnal Ilmiah Teknik Mesin 13, no. 1 (June 1, 2019): 8. http://dx.doi.org/10.24853/sintek.13.1.8-14.
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Heat exchangers or heat exchangers are tools used to change the temperature of the fluid or change the fluid phase by exchanging heat with another fluid. In a heat exchanger, the ability to exchange heat is largely determined by the type of fluid flow and fluid passing through the heat exchanger. The use of heat exchangers in the field of drying is now a necessity to overcome the problems of drying productivity. The purpose of this study was carried out to determine the effectiveness of the heat exchanger experimentally based on directional flow by comparing construction using baffle and without using baffle in an effort to optimize the drying system. The research method was carried out by fabricating 2 units of heat exchangers and by field testing. The test data obtained are the input and output temperatures of the heating fluid flow and cooling fluid flow and flow velocity. Based on preliminary research data shows that the use of baffle affects the increase in temperature on the heat exchanger, where at the fresh air outlet that does not use baffle produces a temperature of 72oC while the baffle produces 88oC with the Log Mean Temperature Difference heat exchanger without using a baffle higher than heat exchanger that uses a baffle guide blade. This can illustrate that the smaller heat losses are wasted so that the absorption of heat by the reverse system will be higher.
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Cui, W. H., L. H. Gong, Q. M. Jia, Z. Y. Li, M. He, W. P. Zhu, and M. M. Zhang. "Numerical study of heat transfer characteristics of intermittent flow cold storage surface heat exchanger." IOP Conference Series: Materials Science and Engineering 1301, no. 1 (May 1, 2024): 012036. http://dx.doi.org/10.1088/1757-899x/1301/1/012036.
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Abstract The intermittent flow cold storage surface heat exchanger is a key component of the new pulse tube expansion cryogenic refrigerator, which is responsible for the periodic heat transfer of cold and hot helium, and its heat exchange efficiency directly affects the thermodynamic efficiency of the whole machine. In this study, a three-dimensional model of the heat exchanger unit is established, and numerical simulation is employed to investigate its heat exchange characteristics. The analysis focuses on understanding the internal temperature distribution patterns within the heat exchanger and explores the influence of wall materials on its heat transfer characteristics. Results show that the existence of the temperature lag loop minimizes the effective heat transfer temperature difference, consequently decreasing the heat exchanger’s efficiency. Moreover, the choice of wall material significantly affects the performance of the heat exchanger, with optimal thermal conductivity and volumetric specific heat enhancing its efficiency. This research provides valuable insights for future design and improvement of similar heat exchangers.
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Yu, Chao, Mingzhen Shao, Wenbao Zhang, Guangyi Wang, and Mian Huang. "Study on Heat Transfer Synergy and Optimization of Capsule-Type Plate Heat Exchangers." Processes 12, no. 3 (March 18, 2024): 604. http://dx.doi.org/10.3390/pr12030604.
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An efficient and accurate method for optimizing capsule-type plate heat exchangers is proposed in this paper. This method combines computational fluid dynamics simulation, a backpropagation algorithm and multi-objective optimization to obtain better heat transfer performance of heat exchanger structures. For plate heat exchangers, the heat transfer coefficient j and friction coefficient f are a pair of contradictory objectives. The optimization of capsule-type plate heat exchangers is a multi-objective optimization problem. In this paper, a backpropagation neural network was used to construct an approximate model. The plate shape was optimized by a multi-objective genetic algorithm. The optimized capsule-type plate heat exchanger has lower flow resistance and higher heat exchange efficiency. After optimization, the heat transfer coefficient is increased by 8.3% and the friction coefficient is decreased by 14.3%, and the heat transfer effect is obviously improved. Further, analysis of flow field characteristics through field co-ordination theory provides guidance for the further optimization of plates.
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Kamarudin, Saddam, Iskhrizat Taib, Muhammad Shaiful Izzat Shaharudin, Muhammad Aiman Nasri, Muhammad Zulfaqar Mohd Madzni, Muhammad Nur Aiman Rahmat, and Muhammadu Masin Muhammadu. "CFD Analysis of Different Baffles in Shell and Tube Exchanger." Semarak Journal of Thermal Fluid Engineering 1, no. 1 (April 25, 2025): 1–10. https://doi.org/10.37934/sjotfe.1.1.110a.
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Shell and tube heat exchangers are among the most common equipment in industrial processes because of their heat exchange efficiency. However, designing these heat exchangers to enhance their performance can be cumbersome and time-consuming. This study focuses on evaluating the performance of shell and tube heat exchangers with different numbers of baffles placed inside the shell, and identifying the most suitable turbulence model. In this study, the flow characteristics inside the heat exchangers were modelled using three turbulence models: Spalart-Allmaras, k-ε standard, and k-ε realisable models. The simulations were performed with the number of baffles ranging from one to seven to understand their effect on heat transfer and pressure drop. When the number of baffles in the heat exchanger increases, the pressure drop across the heat exchanger also increases. Model D exhibited maximum pressure distribution, which occurred with 12 baffles. The velocity streamlines from the experiment showed that a higher number of baffles led to an increase in flow. This study also aimed to compare three turbulence models, and the results indicated that the k-ε realisable model performed the best of the three models. This study also highlights the importance of designing a shell and tube heat exchanger with an appropriate number of baffles. Although more baffling is advantageous for heat transfer, it also results in a higher pressure drop. In summary, as evidenced by the results presented in this paper, the baffle design is crucial for heat exchangers.
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Nitheesh, Krishnan M. C* B. Suresh Kumar. "REVIEW ON SHELL AND TUBE HEAT EXCHANGER USING NANOFLUIDS." INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY 6, no. 5 (May 10, 2017): 236–39. https://doi.org/10.5281/zenodo.573648.
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Different types of heat exchangers are extensively used in various industries to transfer the heat between cold and hot fluids. The key role of the heat exchanger is to transfer heat at maximum rate .Shell and Tube heat exchangers are having special importance in boilers, oil coolers, condensers, pre-heaters. Shell and Tube heat exchanger is one such heat exchanger, provides more area for heat transfer between two fluids in comparison with other type of heat exchanger. To intensify heat transfer with minimum pumping power innovative heat transfer fluids called Nano fluids have become the major area of research now a days. This Review paper summarizes the important articles published on the effect of the heat transfer characteristics in shell and tube heat exchangers using Nano fluids. The review of previous works by researchers suggests that Nano fluids have great potential in augmentation of heat transfer of a heat exchanger. Nano fluid is advanced heat transfer fluid for next generation
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Zhou, Tao, Bingchao Chen, and Huanling Liu. "Study of the Performance of a Novel Radiator with Three Inlets and One Outlet Based on Topology Optimization." Micromachines 12, no. 6 (May 21, 2021): 594. http://dx.doi.org/10.3390/mi12060594.
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In recent years, in order to obtain a radiator with strong heat exchange capacity, researchers have proposed a lot of heat exchangers to improve heat exchange capacity significantly. However, the cooling abilities of heat exchangers designed by traditional design methods is limited even if the geometric parameters are optimized at the same time. However, using topology optimization to design heat exchangers can overcome this design limitation. Furthermore, researchers have used topology optimization theory to designed one-to-one and many-to-many inlet and outlet heat exchangers because it can effectively increase the heat dissipation rate. In particular, it can further decrease the hot-spot temperature for many-to-many inlet and outlet heat exchangers. Therefore, this article proposes novel heat exchangers with three inlets and one outlet designed by topology optimization to decrease the fluid temperature at the outlet. Subsequently, the effect of the channel depth on the heat exchanger design is also studied. The results show that the type of exchanger varies with the channel depth, and there exists a critical depth value for obtaining the minimum substrate temperature difference. Then, the flow and heat transfer performance of the heat exchangers are numerically investigated. The numerical results show that the heat exchanger derived by topology optimization with the minimum temperature difference as the goal (Model-2) is the best design for flow and heat transfer performance compared to other heat sink designs, including the heat exchanger derived by topology optimization having the average temperature as the goal (Model-1) and conventional straight channels (Model-3). The temperature difference of Model-1 can be reduced by 37.5%, and that of Model-2 can be decreased by 62.5% compared to Model-3. Compared with Model-3, the thermal resistance of Model-1 can be reduced by 21.86%, while that of Model-2 can be decreased by 47.99%. At room temperature, we carried out the forced convention experimental test for Model-2 to measure its physical parameters (temperature, pressure drop) to verify the numerical results. The error of the average wall temperature between experimental results and simulation results is within 2.6 K, while that of the fluid temperature between the experimental and simulation results is within 1.4 K, and the maximum deviation of the measured Nu and simulated Nu was less than 5%. This indicated that the numerical results agreed well with the experimental results.
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Wang, Fang, Yunding Li, Mengwei Liu, Dongqing Pang, Weifeng Du, Yichi Zhang, Xiaoqian Cheng, Tangtang Gu, and Wenliang Guo. "Comprehensive Evaluation of the Performances of Heat Exchangers with Aluminum and Copper Finned Tubes." International Journal of Chemical Engineering 2023 (December 20, 2023): 1–11. http://dx.doi.org/10.1155/2023/6666947.
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The finned-tube heat exchanger is the core part of an air conditioning system. Its heat exchange performance directly affects the energy consumption and efficiency of the air conditioner. The shortage and rising price of copper have led to increasing replacement of copper tubes with aluminum tubes in finned-tube heat exchangers. This paper studies two kinds of such heat exchangers, one consisting of copper tubes and aluminum fins and the other consisting of aluminum tubes and aluminum fins. The influences of the different base tube materials on heat transfer are compared and analyzed in terms of heat transfer strength and cost per unit heat transfer. The results show that the heat transfer and heat transfer coefficient increase with increasing inlet wind speed. Under different inlet wind speeds, the heat transfer and heat transfer coefficient of the finned-tube heat exchanger with aluminum tubes are 4%–12% and 7%%–9% lower than those of an identically structured heat exchanger with copper tubes, respectively. The aluminum-aluminum exchanger achieves 67% higher heat transfer than that of the copper-aluminum exchanger at only 8% of the cost. These results are significant for guiding the development and application of finned-tube heat exchangers.
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Liu, Qing Yun, Fu Bing Tu, and Sheng Yang Gao. "Numerical Simulation and Optimization of Radial Heat Pipe Heat Exchanger Based on Field Synergy Principle." Advanced Materials Research 834-836 (October 2013): 1418–22. http://dx.doi.org/10.4028/www.scientific.net/amr.834-836.1418.
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This paper mainly explores the numerical simulation of flow and temperature fields in the shell-side of the radial heat pipe heat exchangers (HPHE), using CFD software-FLUENT. Field synergy principle is applied to analyze heat and mass transfer mechanism of heat exchangers; also, the influence of the variation of principle constructor parameters of heat exchangers on the field synergy effect and heat exchange performance has been studied. It has been found that better performance of heat exchangers is achieved with better field synergy effect; in the context of increasing transverse and longitudinal tube pitches within certain values of data, the heat transfer coefficient decreases as synergy angle increases. Variation of fin height has little effect on synergy angle, but it would decrease the heat transfer coefficient at unit pressure drop (k/Δp) as it increases; as fin pitch increases, the synergy angle first decreases and then grows, while k/Δp first increases and then decreases. The optimal ranges of heat exchanger structure parameters values were found.
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Sit, M.L., O.I. Goncharov, A.A. Juravliov, V.I. Burciu, and D.V. Timchenko. "Heat Pump Using Heat Exchangers with Variable Heat Transfer Surface." Problemele Energeticii Regionale 3(38) (December 15, 2018): 52–61. https://doi.org/10.5281/zenodo.2222344.
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The paper presents deal with the heat pump designed mainly for heat supply systems using the qualitative law of regulation of the heat supply mode (constant flow rate of the heat carrier). For this purpose, an air-to-water heat pump with carbon dioxide as a refrigerant and compressor driven be gas piston unit is used. The aim of the work is to develop a scheme in which the position of the operating point of the heat pump compressor does not depend on fluctuations in the refrigerant flow rate, as well as using the heat produced by the gas engine - driven by the heat pump compressor. This goal achieves by elaboration of internal heat exchangers with an adjustable heat exchange surface area. The heat exchange surface area regulates by installing of an intermediate heat-conducting cylindrical element between the refrigerant and thermal agent circuits. The intermediate cylindrical element moved by using, for example, an electric stepper drive. The conditions, under which the sleeve can be considered as a thermally thin body. To increase the COP of the heat pump (HP), the additional heat exchanger, installed at the outlet of the ejector used in the pump has been used. It is. In the heat exchanger, the working fluid has been heated by using the waste heat of the gas piston unit (GPU. It had been shown that in the temperature control loop the PI controller may be used, and to compensate for the flow rate pulsations, it is necessary to use a combined control system.
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Dzianik, František, Štefan Gužela, and Eva Puškášová. "Suitability Assessment of Two Types of Heat Exchangers for High Temperature, Naturally Circulating Helium Cooling Loop." Strojnícky casopis – Journal of Mechanical Engineering 69, no. 1 (May 1, 2019): 39–50. http://dx.doi.org/10.2478/scjme-2019-0003.
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AbstractThe paper presents a comparison of the process properties of two types of the heat exchangers designed for the heat removal from a high temperature helium cooling loop with steady natural circulation of helium. The first considered heat exchanger is a shell and tube heat exchanger with U-tubes and the other one is a helical coil heat exchanger. Using the thermal and hydrodynamic process calculations, the thermal performance of the two alternative heat exchangers are determined, as well as the pressure drops of flowing fluids in their workspaces. The calculations have been done for several defined operating conditions of two considered types of heat exchangers. The operating conditions of heat exchangers correspond to the certain helium flow rates.
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Kumar, Sunil, and Ravindra Mohan. "A Review on The CFD Analysis of Nano Water Fluid On Helically Coiled Double Tube Heat Exchanger." SMART MOVES JOURNAL IJOSCIENCE 5, no. 10 (October 16, 2019): 3. http://dx.doi.org/10.24113/ijoscience.v5i10.232.
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Heat exchanger is an important device which is used in thermal systems in many industrial fields. Nano fluids are recently employed as coolants to improve the efficacy of heat exchangers. Regarding unique characteristics of Nano fluids, research studies in this area have witnessed a remarkable growth. Latest investigations conducted on use of Nano fluids in heat exchangers including those carried out on plate heat exchangers, double pipe heat exchangers, shell and tube heat exchangers, and compact heat exchangers are reviews and summarized. Meanwhile, some very interesting aspects of Nano fluids in combination with heat exchangers are presented. The challenges and prospects for future research are presented in this paper.
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Mikielewicz, Dariusz, and Jan Wajs. "Possibilities of Heat Transfer Augmentation in Heat Exchangers with Minichannels for Marine Applications." Polish Maritime Research 24, s1 (April 25, 2017): 133–40. http://dx.doi.org/10.1515/pomr-2017-0031.
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Abstract In the paper, new trends in the development of microchannel heat exchangers are presented. The exchangers developed in this way can be applied in marine industry. Main attention is focused on heat exchanger design with reduced size of passages, namely based on microchannels. In authors′ opinion, future development of high power heat exchangers will be based on networks of micro heat exchangers.
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O.R., Abdurakhmonov, and Islomov A.N. "THE USE OF HEAT EXCHANGERS IN THE PROCESSING OF NATURAL COMPOUNDS." Educational Research in Universal Sciences 2, no. 6 (June 30, 2023): 50–53. https://doi.org/10.5281/zenodo.8104029.
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This article provides information on the importance of using heat exchangers in the development, transportation and processing of one of the natural organic compounds - hydrocarbon raw materials in the oil and gas processing industry. Heat exchangers are important at every stage of oil and gas processing. The use of heat exchange equipment makes it possible to facilitate the flow of technological processes. It is known that the main types of heat exchangers are shell and tube heat exchangers, as well as plate heat exchangers, the share of which is currently 38% and continues to grow.
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Liu, Xingyu, and Guangji Li. "A multi-fluid heat transfer spiral coil microchannel heat exchanger based on CFD." Journal of Physics: Conference Series 3009, no. 1 (May 1, 2025): 012047. https://doi.org/10.1088/1742-6596/3009/1/012047.
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Abstract Currently, most microchannel heat exchangers are limited to providing heat transfer between one or two working fluids. However, in fields such as waste heat recovery, and solar thermal power generation, there is a need for energy conversion between multiple media. Consequently, this study introduces a microchannel heat exchanger with a spiral coil structure designed to facilitate simultaneous heat transfer with two or more working fluids. The heat exchange units of this microchannel heat exchanger feature two semicircular cross-section spiral channels that are alternately wound around a circular central channel; the flow channels are tightly attached to the central channel and arranged in an alternating spiral pattern, which increases the heat exchange area. The direction of the working fluid flow within the spiral channels continuously changes, reducing areas of uneven heat transfer. This research establishes a physical model of the spiral coil microchannel heat exchanger and simulates the cooling effect of hot fluids in two arrangements within a SCO2 Brayton cycle. These findings provide a reference for the study of novel structures in microchannel heat exchangers.
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Dou, Jie, and Fude Wang. "Simulation study on optimization design of small gas water heat exchangers." Journal of Physics: Conference Series 2835, no. 1 (August 1, 2024): 012070. http://dx.doi.org/10.1088/1742-6596/2835/1/012070.
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Abstract Gas water heat exchangers are widely used and indispensable in solar heating and hot water engineering. The high-efficiency and energy-saving of heat exchangers is a development trend. This article studies small gas-water heat exchangers and designs and improves the structure of the heat exchanger. We simulate the airflow situation of the heat exchanger and further optimize the small gas-water heat exchanger based on simulation data to improve its operating conditions, thereby improving heat transfer efficiency, reducing wear, and increasing service life.
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Ding, Yi, Qiang Guo, Wenyuan Guo, Wenxiao Chu, and Qiuwang Wang. "Review of Recent Applications of Heat Pipe Heat Exchanger Use for Waste Heat Recovery." Energies 17, no. 11 (May 23, 2024): 2504. http://dx.doi.org/10.3390/en17112504.
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With the reduction in fossil fuels and growing concerns about global warming, energy has become one of the most important issues facing humanity. It is crucial to improve energy utilization efficiency and promote a low-carbon transition. In comparison with traditional heat exchangers, heat pipe heat exchangers indicate high compactness, a flexible arrangement, complete separation of hot and cold fluids, good isothermal operations, etc. As a result, heat pipe heat exchangers have attracted wide attention and application in various fields in recent years. This paper provides an overview of the application of heat pipe heat exchangers, with a focus on the application in waste heat recovery, and analyzes the opportunities and challenges of heat pipe heat exchanger applications based on existing publications.
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Ghosh, I., S. K. Sarangi, and P. K. Das. "Simulation Algorithm for Multistream Plate Fin Heat Exchangers Including Axial Conduction, Heat Leakage, and Variable Fluid Property." Journal of Heat Transfer 129, no. 7 (December 27, 2006): 884–93. http://dx.doi.org/10.1115/1.2717938.
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The effect of axial conduction through heat exchanger matrix, heat exchange with the surroundings, and variable fluid properties are included in the simulation algorithm of multistream plate fin heat exchangers. The procedure involves partitioning of the exchanger in both axial and normal directions, writing conservation equations for each segment, and solving them using an iterative procedure. In the normal direction, the exchanger is divided into a stack of overlapping two-stream exchangers interacting through their common streams. In the axial direction, the exchanger is successively partitioned to 2k segments, the final value of k being determined by the point where further partitioning has only marginal effect. The effects of axial conduction, heat leakage, and variable fluid properties are illustrated with the help of multistream heat exchanger examples solved by the above-mentioned technique.
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Zhelykh, Vasyl, Olena Savchenko, and Vadym Matusevych. "Horizontal earth-air heat exchanger for preheating external air in the mechanical ventilation system." Selected Scientific Papers - Journal of Civil Engineering 13, no. 1 (December 1, 2018): 71–76. http://dx.doi.org/10.1515/sspjce-2018-0021.
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Abstract To save traditional energy sources in mechanical ventilation systems, it is advisable to use low-energy ground energy for preheating or cooling the outside air. Heat exchange between ground and outside air occurs in ground heat exchangers. Many factors influence the process of heat transfer between air in the heat exchanger and the ground, in particular geological and climatic parameters of the construction site, parameters of the ventilation air in the projected house, physical and geometric parameters of the heat exchanger tube. Part of the parameters when designing a ventilation system with earth-air heat exchangers couldn’t be changed. The one of the factors, the change which directly affects the process of heat transfer between ground and air, is convective heat transfer coefficient from the internal surface of the heat exchanger tube. In this article the designs of a horizontal earthair heat exchanger with heat pipes was proposed. The use of heat pipes in designs of a horizontal heat exchanger allows intensification of the process of heat exchange by turbulence of air flow inside the heat exchanger. Besides this, additionally heat transfer from the ground to the air is carried out at the expense of heat transfer in the heat pipe itself.
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Jayesh, V. Bute, and Dr.S.H.Mankar. "Effect of varying inlet water temperature on performance of three pass helical coil heat exchanger." Journal of Thermal Energy Systems 4, no. 2 (May 28, 2019): 1–6. https://doi.org/10.5281/zenodo.3233485.
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The straight tube heat exchanger is used mostly in industries such as evaporator or condenser for chemical industry and cooling fluid system. The straight tube heat exchanger consumes more space but offers lesser surface area of contact. This type of heat exchanger provides only one type of flow in single pass. Now there is need of such type of heat exchanger which increases the effectiveness with saving in cost. To improve the efficiency of heat exchanger one must think of heat transfer enhancement in heat exchanger which can help to minimize the problems associated with conventional heat exchangers in near future. Energy and material saving considerations as well as environmental challenges in the industry have increased the demand of New Design for high efficiency heat exchanger. To improve the efficiency of heat exchanger we must think of heat transfer enhancement in heat exchanger.Helical coil heat exchangers are one of the most commonly found equipment in many industry.The helical coil heat exchangers can be made in the form of a cylindrical or shell and tube heat exchangers and it be used for several industrial applications such as power plant, nuclear power plant sector, food process industry, waste heat recovery systems, HVAC industry etc. Helical coil Configuration is very efficient for heat exchangers design because it can accommodate a large heat area for heat transfer in a small space, with high heat transfer coefficients of performance. Heat Transfer Coefficient always increases in helical coil heat exchanger configuration due to centrifugal force generated in it.
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Kovarik, M. "Optimal Heat Exchangers." Journal of Heat Transfer 111, no. 2 (May 1, 1989): 287–93. http://dx.doi.org/10.1115/1.3250676.
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The design of optimal heat exchangers is formulated as the solution of five simultaneous equations. The analysis of these equations yields general properties of optimal crossflow heat exchangers; in particular, an upper bound of 1/3 is given for the fractional cost of maintaining the flow through the heat exchanger. Some of these general properties also apply in the presence of a simple constraint. It is shown that some technically feasible designs cannot be optimal under realistic costs and others under any costs.
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Dawood Jumaah, Itimad, Senaa Kh. Ali, and Anees A. Khadom. "Evaluation Analysis of Double Coil Heat Exchanger for Heat Transfer Enhancement." Diyala Journal of Engineering Sciences 14, no. 1 (March 15, 2021): 96–107. http://dx.doi.org/10.24237/djes.2021.14109.
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In order to maximize the thermal efficiency of shell and coil heat exchangers, substantial research has been done and geometrical modification is one way to improve the exchange of thermal energy between two or more fluids. One of the peculiar features of coiled geometry is that the temperature distribution is highly variable along the circumferential section due to the centrifugal force induced in the fluid. Moreover, most researchers are concentrated on using a shell and single helical coil heat exchanger to enhance the heat transfer rate and thermal efficiency at different operating parameters. Therefore, the aim of this study is to investigate temperature variation ((T-1, T-2, T-3 and T-4) across a shell and single/double coil heat exchanger at different coil pitches, hot water flow rate, and cold-water flow rate along the outer surface of the coil using experimental and numerical analysis. For single and double coil heat exchangers, Computational Fluid Dynamics (CFD) is carried out using pure water with a hot water flow rate ranging between 1-2 l/min for the coil side heat exchanger. For single coil heat exchangers, the numerical analysis findings showed a good agreement with experimental four-temperature measurement results (T-1, T-2, T-3 and T-4) with an error rate of 1.80%, 3.05%, 5.34% and 2.17% respectively. Moreover, in the current double coil analysis, the hot outlet temperature decreased by 3.07% compared to a single coil (baseline case) at a 2.5L/min hot water flow rate. In addition, increasing the coil pitch will increase the contact between the hot fluid and the coil at a constant hot water flow rate and thereby decrease the hot fluid outlet temperature. Finally, a computational analysis was carried out to examine the flow structure inside single and double coil heat exchangers, and the findings indicated that the effect of centrifugal forces in double coil heat exchangers at various coil pitches caused the secondary flow to be substantially reduced.
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Dahl, S. D., and J. H. Davidson. "Performance and Modeling of Thermosyphon Heat Exchangers for Solar Water Heaters." Journal of Solar Energy Engineering 119, no. 3 (August 1, 1997): 193–200. http://dx.doi.org/10.1115/1.2888018.
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Determining the performance of indirect solar heating systems that use thermosyphon heat exchangers requires knowledge of how thermosyphon flow rate and heat exchanger performance vary with operating conditions. In this paper, measured performance of a two-pass, tube-in-shell, double-wall heat exchanger is discussed in terms of modeling issues. Thermosyphon heat exchangers may operate in the developing, mixed convection regime where natural convection effects can significantly influence overall heat transfer and friction coefficients. Existing models which assume the thermal and hydraulic behaviors of thermosyphon heat exchangers are only functions of the thermosyphon and collector flow rates may not be suitable for all heat exchanger types. For example, the overall heat-transfer coefficient-area product for the two-pass, tube-in-shell heat exchanger is best expressed as a function of Reynolds, Grashof, and Prandtl numbers on the thermosyphon side of the heat exchanger. It is proposed that annual simulations of solar water heaters with thermosyphon heat exchangers use this type of relationship to characterize heat transfer in the heat exchanger.
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Veerabhadrappa, Kavadiki, Dhanush Dayanand, Darshan Dayanand, Vinayakaraddy, K. N. Seetharamu, and Preadeep Hegde. "Analysis of Two Fluid Four-Channel Heat Exchanger Using Finite Element Method." Applied Mechanics and Materials 813-814 (November 2015): 658–62. http://dx.doi.org/10.4028/www.scientific.net/amm.813-814.658.
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The development of heat exchangers from two streams to multi-stream passage arrangement becomes a key problem for heat exchanger design. In this paper, a new design is developed for multi-stream (four-channel) heat exchanger. Multi-channel heat exchangers are extensively used in refrigeration and air conditioning, chemical industries, milk pasteurization, cryogenics industries and energy-recovery applications due to their higher heat transfer rates. The focus of this study is to determine the performance of four-channel counter flow heat exchanger. The hot and cold fluids are assumed to recirculate and exchange heat between them. Finite element model of the heat exchanger is developed based on the detailed geometry and the specific working conditions with the help of which effectiveness of the four-channel heat exchanger is computed. Non-Dimensional parameters are introduced which makes the analysis more versatile. The effectiveness is computed for different values of NTU and heat capacity ratio.