Journal articles: 'Energy exchange'

1

McCarthy, Nicola. "Energy exchange." Nature Reviews Cancer 6, no. 8 (July 13, 2006): 581. http://dx.doi.org/10.1038/nrc1955.

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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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Armarego-Marriott, Tegan. "Ecosystem energy exchange." Nature Climate Change 11, no. 6 (June 2021): 466. http://dx.doi.org/10.1038/s41558-021-01078-7.

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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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Sekulic, D. P. "The Second Law Quality of Energy Transformation in a Heat Exchanger." Journal of Heat Transfer 112, no. 2 (May 1, 1990): 295–300. http://dx.doi.org/10.1115/1.2910375.

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This paper presents the entropy generation (irreversibility) concept as a convenient method for estimating the quality of the heat exchange process in heat exchanger analysis. The entropy generation caused by finite temperature differences, scaled by the maximum possible entropy generation that can exist in an open system with two fluids, is used as the quantitative measure of the quality of energy transformation (the heat exchange process). This measure is applied to a two-fluid heat exchanger of arbitrary flow arrangement. The influence of different parameters (inlet temperature ratio, fluid flow heat capacity rate ratio, flow arrangements) and the heat exchanger thermal size (number of heat transfer units) on the quality of energy transformation for different types of heat exchangers is discussed. In this analysis it is assumed that the contribution of fluid friction to entropy generation is negligible.

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Higuchi, Katsuhiko. "Word "Energy" - Exchange of Main Energy." Journal of The Japan Institute of Marine Engineering 44, no. 6 (2009): 979. http://dx.doi.org/10.5988/jime.44.979.

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Qiu, Wenhai. "Study on the random walk classification algorithm of polyant colony." Open Computer Science 12, no. 1 (January 1, 2022): 378–88. http://dx.doi.org/10.1515/comp-2022-0248.

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Abstract With the sustained and healthy development of economy, saving energy and reducing consumption and improving energy utilization rate is a major task that enterprises need to solve. With the complex and large-scale chemical process, the heat exchange network has become complex and diverse. For more and more complex and large-scale industrial heat exchange networks, there are many different kinds of heat exchangers, the flow is complex, so the heat exchange network presents a high degree of complexity, a node status change; its disturbance transfer will influence the stability of other nodes associated with it, because of the system coupling, thus affecting the controllability and reliability of the whole heat exchanger network. Process optimization design of heat exchange network is one of the main methods of energy saving in the industrial field. As a typical simulated evolutionary algorithm in swarm intelligence algorithm, ant colony algorithm combined with random walk classification algorithm, this article proposes an optimized heat transfer network based on multi-ant colony random walk classification algorithm. The heat exchanger was abstracted as a node, and the heat exchanger pipeline was abstracted as a side. According to the maximum geometric multiplicity of the eigenvalue of the adjacency matrix and the linear correlation row vector of the matrix, and combining the importance of the edge of the heat exchange network with the controllable range of the driving edge, the optimal control driving edge of the heat exchange network is identified. The results show that compared with the traditional heat exchanger, the size of the enhanced heat transfer equipment and the influence of pressure drop change. Compared with the results of the size of the heat exchanger strengthening heat transfer equipment and the stepwise optimization of the heat exchange network in this study, the cost of public engineering is reduced by 5.98% and the total cost is reduced by 8.83%.

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Bohn, M. S. "Air Molten Salt Direct-Contact Heat Exchange." Journal of Solar Energy Engineering 107, no. 3 (August 1, 1985): 208–14. http://dx.doi.org/10.1115/1.3267680.

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Volumetric heat transfer coefficients for direct-contact heat exchange between air and molten nitrate salt have been measured as a function of air and salt flow rates at 350° C salt inlet temperature. Using these heat transfer data for a packed column-type heat exchanger, an economic analysis was used to compare direct-contact heat exchange with conventional finned-tube heat exchangers. High volumetric rates of heat transfer (2000–3000 W/m3 °C) and flexibility in choice of materials of construction allow one to realize significant economic benefits by using direct-contact heat exchange in this application.

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Andriotis, Antonis N. "LDA exchange-energy functional." Physical Review B 58, no. 23 (December 15, 1998): 15300–15303. http://dx.doi.org/10.1103/physrevb.58.15300.

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Mayer, I., and A. Hamza. "Interatomic exchange energy components." International Journal of Quantum Chemistry 92, no. 2 (2003): 174–80. http://dx.doi.org/10.1002/qua.10504.

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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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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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Robles, Juvencio, and Gary Kemister. "Is correlation energy proportional to exchange energy?" Chemical Physics Letters 134, no. 1 (February 1987): 27–33. http://dx.doi.org/10.1016/0009-2614(87)80007-6.

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Warman, J. M., and M. P. de Haas. "Hot Electron Energy Exchange in Liquid Hot Electron Energy Exchange in Liquid Xenon." IEEE Transactions on Electrical Insulation EI-20, no. 2 (April 1985): 147–52. http://dx.doi.org/10.1109/tei.1985.348792.

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PUMSA-ARD, K., W. UCHAI, and Y. YAN. "MESON EXCHANGE THEORY FOR HIGH ENERGY PROTON-PROTON SCATTERING." International Journal of Modern Physics E 15, no. 01 (February 2006): 109–19. http://dx.doi.org/10.1142/s0218301306003898.

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We study high energy proton-proton (pp) elastic reactions in a meson-exchange model. The observed differential cross sections at small momentum exchanges (|t|<0.8 GeV 2) are well reproduced for a large energy range (s~100 to 1000 GeV 2) in the model. Our study reveals that the meson-exchange model developed in the low and medium energy sector is applicable to the high-energy pp elastic reactions. It might be argued that high-energy reactions at small momentum transfers might be as soft as low and medium energy processes.

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Thai Hung, Ngo. "Interdependence of oil prices and exchange rates: Evidence from copula-based GARCH model." AIMS Energy 7, no. 4 (2019): 465–82. http://dx.doi.org/10.3934/energy.2019.4.465.

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17

Tsuzuki, Yuto, Yutaro Akimoto, and Keiichi Okajima. "Preventive control method for stable operation of proton exchange membrane fuel-cell stacks." AIMS Energy 11, no. 1 (2023): 64–78. http://dx.doi.org/10.3934/energy.2023004.

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<abstract> <p>Flooding and dry-out are major drawback issues in proton exchange membrane fuel cells (PEMFC), which necessitate adequate prevention control techniques. In a fuel-cell stack, as flooding and dry-out occur on the inlet and outlet sides, respectively, both faults can exist simultaneously. Therefore, the timely detection of these two contradictory faults is crucial for implementing timely control measures. In this study, we propose a preventive control method that detects the fault signs early for more effective prevention. The proposed method uses a curve-fitting method, which uses overpotential as the control index. As the control index can be obtained by measuring the current, voltage, and temperature, the evaluation can be performed quickly, making it easy to implement in a PEMFC system. Under a single fault, the stack output power, hydrogen consumption, and power efficiency of the proposed preventive control method and the previous study on flooding were compared. The results showed that our preventive control method could detect flooding sooner and was superior in stack output power, hydrogen consumption, and power generation compared to the fault control method. Under conditions of mixed flooding and dry-out, both flooding and dry-out were detected using the overpotential as the control index. Thus, because the proposed method initiates control measures before the fault progresses, it is possible to ensure the continued stable operation of the fuel cells.</p> </abstract>

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Smith, J. B., and L. Smith. "Energy dependence of sodium-calcium exchange in vascular smooth muscle cells." American Journal of Physiology-Cell Physiology 259, no. 2 (August 1, 1990): C302—C309. http://dx.doi.org/10.1152/ajpcell.1990.259.2.c302.

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Three different types of mitochondrial poisons (oligomycin, antimycin A, and dinitrophenol) strongly inhibited Na(+)-Ca2+ exchange in aortic myocytes. Exchange activity was assayed as 45Ca2+ uptake that depended on inverting the Na+ gradient and was inhibited by 25 microM dimethylbenzamil. Glucose markedly decreased the inhibition of exchange activity by these three poisons. Glucose also prevented rotenone from inhibiting exchange and depleting cellular ATP. In the absence of glucose, rotenone decreased ATP and exchange activity with half-times of 0.8 and 0.9 min, respectively. Almost eliminating cellular ATP with rotenone maximally inhibited exchange by 80%. Repletion of ATP with glucose substantially restored Na(+)-Ca2+ exchange activity. Ca2+ uptake by organelles, subsequent to entry via exchange for Na+, does not appear to contribute significantly to exchange activity as assayed in intact myocytes. The specific activity of Na(+)-Ca2+ exchange was approximately 30 nmol.min-1.mg protein-1. These findings suggest that ATP modulates exchange activity and that there are approximately 150,000 Na(+)-Ca2+ exchangers per cell, assuming that the turnover number is 1,000 s-1.

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Nasibullina, O. A., and D. D. Kasintseva. "Study of the effect of the annular gap between the kta housing and the transverse segment partitions on the heat exchange efficiency." Journal of Physics: Conference Series 2373, no. 5 (December 1, 2022): 052032. http://dx.doi.org/10.1088/1742-6596/2373/5/052032.

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Abstract In modern industry, specially designed devices, called heat exchangers, are used to carry out heat exchange between working bodies (heat exchangers). They are widely used in all industries (chemical, oil and gas, food, etc.), which is due to the high reliability of the design, high productivity, simplicity of design and a variety of types and designs. The objective of the investigation is to simulate heat exchange in a shell-and-tube heat exchanger without an annular gap between the housing and segment transverse partitions and with a gap equal to 6 mm, and then determine at which of these two gaps the heat exchanger thermal efficiency is highest. The simulation was performed in ANSYS Workbench. The comparison of the energy efficiency of the apparatus was made using the Kirpichev criterion. This criterion is quite simple and does not require finding a large number of various parameters. With this criterion, it is possible to determine in which case the heat exchanger will be most advantageous in terms of energy efficiency.

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Sarkar, S., and A. K. SenGupta. "A hybrid ion exchange-nanofiltration (HIX-NF) process for energy efficient desalination of brackish/seawater." Water Supply 9, no. 4 (October 1, 2009): 369–77. http://dx.doi.org/10.2166/ws.2009.634.

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This study reports a new hybrid ion exchange-nanofiltration (HIX-NF) process for desalination of sea and brackish water that can attain significant energy economy over the conventional membrane-based pressure driven processes. In this hybrid process, an ion exchange step converts monovalent chloride ions of saline water to divalent sulfate ions and the resulting solution, having a reduced osmotic pressure than the feed, is desalinated using a nanofiltration (NF) membrane. The sulfate rich reject stream from the NF process is used to regenerate the anion exchanger. Results validate that NF membranes can desalinate sodium sulfate solution at a much lower transmembrane pressure compared to RO membranes as well as yield a higher permeate flux. The sulfate-chloride selectivity of the anion exchangers plays important role in sustainability of the process. Laboratory studies have revealed that a single type of anion exchanger cannot sustain the process for saline water with different salt concentrations. However, anion exchangers with different sizes of amine functional groups (e.g. quaternary-, tertiary-, secondary- and primary amine) hold the promise that the process can be tailored to achieve sustainability. Laboratory studies have validated the basic premise of the hybrid process including greater than two times less energy requirement than RO process for the same feed water and same permeate recovery condition.

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Lin, Chao-Cheng, Chih-Huang Lai, Ruo-Fan Jiang, and Han-Ping D. Shieh. "High interfacial exchange energy in TbFeCo exchange-bias films." Journal of Applied Physics 93, no. 10 (May 15, 2003): 6832–34. http://dx.doi.org/10.1063/1.1556932.

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Batukhtin, Sergey, Andrey Batukhtin, and Marina Baranovskaya. "Water-air regenerative heat exchanger with increased heat exchange efficiency." E3S Web of Conferences 295 (2021): 04005. http://dx.doi.org/10.1051/e3sconf/202129504005.

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According to experts’ forecasts, by 2040 the global demand for energy will increase by 37%, and renewable energy sources in the next 20 years will become the fastest growing segment of the world energy, their share in the next decade will grow by about one and a half times. Solar energy is the fastest growing industry among all non-conventional energy sources and is gaining the highest rates of development in comparison with other renewable energy sources. In this article, the authors provide an overview of the technologies that increase the efficiency and productivity of solar panels, only the investigated methods are described that can speed up the process of introducing solar energy instead of traditional. All the methods described can increase the efficiency of systems that are based on the use of the sun as the main source of energy. The authors presented and described the scheme of a solar-air thermal power plant, which will improve energy efficiency through the use of a regenerative air solar collector with increased heat transfer efficiency. Strengthening will be achieved through the use of hemispherical depressions on the surface that receives solar radiation. A schematic diagram is given and the principle of operation of such a solar collector is described in detail. A comparative calculation of the intensification of the solar collector with the use of depressions and without the use as modernization was carried out, on the basis of which a conclusion was made about the efficiency of using this type of solar collector and the economic effect from the application of this method. A description of the method for calculating the solar collector is given, thanks to which this development can be used and implemented in existing heating and hot water supply systems.

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Kuznetsov, V. I., V. V. Makarov, A. Yu Shander, M. Yu Agarin, and I. A. Kuzmenko. "Energy exchange in vortex tube." Omsk Scientific Bulletin. Series Aviation-Rocket and Power Engineering 4, no. 1 (2020): 74–82. http://dx.doi.org/10.25206/2588-0373-2020-4-1-74-82.

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Iwamoto, Eduardo. "Bolsa de Energia “Energy Exchange”." International Journal of Digital Law 2, no. 1 (March 10, 2021): 23–24. http://dx.doi.org/10.47975/ijdl.iwamoto.2021.

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Nos últimos dez anos o Brasil tem sofrido com longos períodos de estiagem, fato inédito em mais de 70 anos de monitoramento da vazão hídrica nacional. Tal condição revelou algumas fragilidades da matriz energética que são indiferentes à crise hídrica, pois utiliza um modelo computacional para promover o controle de inserção de energia elétrica no sistema e estabelece o preço da energia no mercado de curto prazo, denominado de Preço de Liquidação das Diferenças - PLD. A estiagem obriga o Operador Nacional do Sistema – ONS, entidade responsável por controlar o fluxo de energia elétrica no sistema, a recorrer à geração térmica, muito mais cara que a energia de fonte hídrica. Problemas como alta volatilidade do PLD, que repercute na fragilidade de mecanismos de liquidez de contratos de compra e venda de energia elétrica no mercado livre, tem causado contaminação sistêmica e prejuízos aos agentes. A falta de liquidez desses contratos gera instabilidade no mercado livre. Se por um lado o MME imprime esforços para viabilizar um mercado livre de energia, a desconfiança por outro lado é um caminho em outra direção. O objetivo do presente trabalho é debater a viabilidade de implementação de uma bolsa de energia elétrica, analisando os benefícios em relação à robustez e segurança dos negócios jurídicos através dos mecanismos existentes no mercado financeiro. O primeiro resultado da pesquisa foi a conclusão que os contratos negociados no mercado livre possuem características financeiras muito próximas aos derivativos negociados em bolsa de valores, facilitando a implementação de um mercado a termo, com objetivo de criar padrões de contratos de energia e dar sinais claros de precificação. Outro resultado foi a análise de operações de hedge, adotados em bolsa de valores, como por exemplo: câmara de compensação e liquidação; derivativos, arbitragem, swap e opções. Tais operações financeiras podem trazer mais segurança às negociações, afastando risco de iliquidez e melhorando as garantias de entrega física de energia elétrica. Concluiu-se que uma bolsa de energia já está em rota de implementação. As discussões do Grupo de Trabalho de Modernização do Setor, promovido pelo Ministério de Minas e Energia – MME, tem avançado nesse sentido. Iniciativas de entidades privadas como a Brasil, Bolsa e Balcão - B3 e o Balcão Brasileiro de Comercialização de Energia - BBCE, com propostas de prestação de serviços vinculados a derivativos. Ainda há muito a ser discutido, pois algumas reformas no marco legal e no âmbito regulatório devem ser implementadas para trazer mais segurança e previsibilidade aos operadores do mercado de energia.

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Braun, O. M. "Energy exchange in adsorbed layers." Surface Science 213, no. 2-3 (April 1989): 336–58. http://dx.doi.org/10.1016/0039-6028(89)90295-1.

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Braun, O. M. "Energy exchange in adsorbed layers." Surface Science Letters 213, no. 2-3 (April 1989): A222. http://dx.doi.org/10.1016/0167-2584(89)90460-x.

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Pacchioni, Giulia. "Intra-atomic exchange energy quantified." Nature Reviews Materials 5, no. 10 (September 21, 2020): 729. http://dx.doi.org/10.1038/s41578-020-00244-1.

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Burke, Kieron, Federico G. Cruz, and Kin-Chung Lam. "Unambiguous exchange-correlation energy density." Journal of Chemical Physics 109, no. 19 (November 15, 1998): 8161–67. http://dx.doi.org/10.1063/1.477479.

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SHEYKHI, AHMAD. "BRANE–BULK ENERGY EXCHANGE AND AGEGRAPHIC DARK ENERGY." International Journal of Modern Physics D 19, no. 03 (March 2010): 305–16. http://dx.doi.org/10.1142/s0218271810016427.

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We consider the agegraphic models of dark energy in a braneworld scenario with brane–bulk energy exchange. We assume that the adiabatic equation for the dark matter is satisfied while it is violated for the agegraphic dark energy due to the energy exchange between the brane and the bulk. Our study shows that with the brane–bulk interaction, the equation of state parameter of agegraphic dark energy on the brane, wD, can have a transition from the normal state, where wD > -1, to the phantom regime, where wD < -1, while the effective equation of state for dark energy always satisfies [Formula: see text].

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Shcherba, А. A., and N. I. Suprunovska. "ELECTRIC ENERGY LOSS AT ENERGY EXCHANGE BETWEEN CAPACITORS AS FUNCTION OF THEIR INITIAL VOLTAGES AND CAPACITANCES RATIO." Tekhnichna Elektrodynamika 2016, no. 3 (April 18, 2016): 9–11. http://dx.doi.org/10.15407/techned2016.03.009.

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Kim, Jung-Sook, and Hyun-Woo Koo. "Development of esXML for Energy Information Exchange." Journal of Korean Institute of Intelligent Systems 19, no. 2 (April 25, 2009): 197–205. http://dx.doi.org/10.5391/jkiis.2009.19.2.197.

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Nagy, A. "Exchange energy in the exact exchange-only density functional theory." Journal of Physics B: Atomic, Molecular and Optical Physics 26, no. 1 (January 14, 1993): 43–48. http://dx.doi.org/10.1088/0953-4075/26/1/004.

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Zhu, Xiao Qin, Zhao Sheng Cao, Zi Yue Zhu, Jing Hua Chang, Hai Ming Gu, and Hai Bin Yang. "Heat Energy Storage Characteristics of a New Type of PCM Heat Exchange Tube." Advanced Materials Research 550-553 (July 2012): 3131–34. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.3131.

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Heat energy storage characteristics of a new type of PCM heat exchange tube was researched, in which it took the traditional double-tube exchanger as the total construction foundation and phase change material(CaCl2•6H2O) was filled in the annular area between the inner tube and the outer tube. As air with different temperatures flowed through the PCM heat exchange tube, temperature measurements were carried out at the inlet and the outlet by the experimental system. The experimental results showed that, a new type of PCM heat exchange tube could store heat energy from the hot air by the phase change material in the annular area, and discharge the stored heat energy into the required fluid if necessary. Thus it has two functions of heat exchange and heat energy storage, and is mainly suitable for recovery and utilizations of heat energy in greenhouses, buildings, air conditioning and manifold industrial afterheat or waste heat.

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Hua, Hong Jian, Abudulkareem Sh Mahdi Al-Obaidi, Chin Wai Meng, and Kenny James Ling Neng Hui. "Effect of Supply and Exhaust Air Velocity on the Enthalpy and Temperature Exchange Efficiency of a Paper Heat Exchanger." MATEC Web of Conferences 335 (2021): 03006. http://dx.doi.org/10.1051/matecconf/202133503006.

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Heat Recovery Ventilators (HRV) are gradually becoming more popular in urban cities and buildings as it is able to effectively maintain the indoor air quality while also using minimal amounts of energy. The key component in the HRV is the Paper Heat Exchanger, which allows the heat exchange of indoor and outdoor air through a crossflow, while also filtering out stale air and dust particles. This article investigates the effect of manipulating the supply and exhaust air velocity on the enthalpy and temperature exchange efficiency of a paper heat exchanger. Data is obtained from experimental results, where the experiments are conducted in a test lab using heat recovery ventilators (HRV) installed with paper heat exchangers. Two paper heat exchangers from different suppliers were tested inside a HRV installed in an air conditioned room. The HRV fan speed was varied at a fixed interval of 0.5 m/s, and the air velocity was measured by using a wind speed meter. At the same time, a USB data logger was used to collect relative humidity and temperature of the air at the supply inlet, indoor air inlet, and return air outlet to determine temperature exchange efficiency and the enthalpy of air. The results of the testing shows that the HRV was able to achieve a temperature exchange efficiency of 47 to 63% and enthalpy exchange efficiency of 63 to 94% for PHEX-A, and a temperature exchange efficiency of 28 to 48% and enthalpy exchange efficiency of 57 to 85% for PHEX-B. The data shows that PHEX-A has higher efficiency than PHEX-B.

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Ernzerhof, Matthias, and Gustavo E. Scuseria. "Kinetic energy density dependent approximations to the exchange energy." Journal of Chemical Physics 111, no. 3 (July 15, 1999): 911–15. http://dx.doi.org/10.1063/1.479374.

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36

Yakovleva, O., O. Ostapenko, and V. Trandafilov. "EN Energy efficiency projects deployment for Ukrainian industry. Efficiency assessment method for energy exchange and the ratio of temperature change in heat exchangers." Refrigeration Engineering and Technology 56, no. 1-2 (July 4, 2020): 54–59. http://dx.doi.org/10.15673/ret.v56i1-2.1829.

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Energy efficiency projects deployment for Ukraine is one of the challenging task today. Ukrainian industry faces very complex environment for project development as well as its deployment within organization nowadays. UA Policy struggle to keep place on the European market to have possibility not only be a part of global policy but to go forward and to bring benefits for macro and micro economy. Fresh breath by integration energy systems within project management into business model of organization let to move closer to hold under control energy efficiency projects realization and avoid financial risks. Environmental policy and energy policy play crucial role for Ukrainian transformation into European player. Presented proactive plan provides possibilities to deliver the intended economic and environmental benefits of the Ukrainian energy labelling and ecological design directives. These directives are in use or are under development process by increasing the rates of compliance with their energy efficiency requirements. To start from the energy efficiency development process investigation in order to have possibilities to make corrections on the stage of modeling and design can bring benefits and reduce costs for end users. To evaluate the efficiency of heat exchangers, there are over 40 different private integral energy efficiency criteria. Such a number makes the estimation of heat exchangers not always objective and sufficiently definite, which does not allow to algorithmize the task of determining the efficiency of heat exchangers. On the foundation of the system element representation for the heat exchange network, the concepts of energy potential and energy efficiency of energy exchange are proposed. The obtained equations allow us to determine the efficiency of energy exchange not only for an element of the heat exchange network, but also for a complex system as a whole with a minimum of information about the system

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37

Mangla, Inayat U., and Jamshed Y. Uppal. "Macro-economic Policies and Energy Security—Implications for a Chronic Energy Deficit Country." Pakistan Development Review 53, no. 3 (September 1, 2014): 255–73. http://dx.doi.org/10.30541/v53i3pp.255-273.

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The paper assesses the energy sector’s foreign exchange requirements for meeting energy consumption and for capital expenditures, and identifies its implications for the country’s macroeconomic policy and management. We develop a conceptual model for projecting the energy sector’s long-term requirements for foreign exchange. The model indicates that the country’s chronic dependence on oil imports is likely to expose the economy to high and volatile oil prices. A fundamental issue for Pakistan is how the energy projects requiring large inflows of foreign capital and technology will be financed. The main implication of our analysis is that there will be continuing pressure on the country’s foreign exchange resources. The demand for foreign exchange by the year 2024-25 is projected to be US$ 20-21 billion without the FDI in new power generation. However, when we include the requirements of foreign exchange for capital expenditure, the total FX requirements are in the range of US$ 23- 24 billion. An implication of the country’s chronic energy deficiency is that the macroeconomic policies, particularly the foreign exchange rate policy, need to be redefined to reflect the projected demands on hard currencies and their expected scarcity value. It is likely that Pakistan will remain dependent on foreign imports to meet its energy requirements for a long time and will need to generate commensurate foreign exchange resources to ensure longterm energy security. JEL classification: E66, F37, Q43 Keywords: Macroeconomic Policy, Exchange Rate Policy, Energy Security

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38

Peregudov, Yuriy S., Sabukhi I. Niftaliev, Anna V. Timkova, Larisa P. Bondareva, and Aleksey V. Astapov. "CHANGE IN THERMODYNAMIC CHARACTERISTICS OF HYDRATION OF CARBOXYL FIBER SORBENT IN EXCHANGE OF MAGNESIUM AND CALCIUM CATION." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, no. 4 (April 16, 2020): 42–48. http://dx.doi.org/10.6060/ivkkt.20206304.6122.

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The relationship between the characteristics of hydration and the selectivity of the fibrous carboxyl sorbent is established. Using the isopiestic method and thermal analysis, the hydration of the carboxyl fiber ion exchanger VION KN-1 in sodium, calcium and magnesium forms was studied. The quantity of absorbed water was determined, including the ratio of kinetically unequal water in the sorbent phase. The amount of water absorbed form of magnesium ion exchanger is greater than calcium, the molar proportion of water distribution varying in the degree of hydration of the magnesium and calcium forms fibers substantially equally. The changes in Gibbs energy of hydration and enthalpy of dehydration of ion-exchange fiber are calculated. The increase in Gibbs energy is due to the absorption of near- hydration water, and water farthest hydration is adsorbed at a constant value of the energy. Its highest values are determined for the magnesium form of the sorbent, and the least-for calcium, which corresponds to the ratio of the absorbed solvent of both forms in the first step of hydration. The exchange isotherms of calcium and magnesium ions on the sodium form of VION KN-1 fiber were obtained. The Gibbs energy of solvent interface transfer was calculated, which represents the difference between the Gibbs energies of ion exchange sorption and the direct exchange of cations, and describes the contribution of the change in sorbent hydration during the transition from one ionic form to another. It is found that the selectivity of extractable fiber ion exchanger to metal cations depending on the change in the sorbent during the hydration of ion exchange, which is energetically favorable process and promotes ion-exchange sorption. Carboxyl cation exchanger is more selective for magnesium ions than calcium ions, as confirmed by phase transfer energy high values solvent and less water released during the transition from the sodium form to the magnesium than during the transition to the calcium.

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39

Caicedo-Ortiz, H. E., and S. T. Perez-Merchancano. "Exchange energy in coupled quantum dots." Brazilian Journal of Physics 36, no. 3b (September 2006): 874–77. http://dx.doi.org/10.1590/s0103-97332006000600020.

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40

Nagy, Á. "Density scaling and exchange-correlation energy." Journal of Chemical Physics 123, no. 4 (July 22, 2005): 044105. http://dx.doi.org/10.1063/1.1979473.

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Viquez Rojas, Claudia I., Jonathan Fine, and Lyudmila V. Slipchenko. "Exchange-repulsion energy in QM/EFP." Journal of Chemical Physics 149, no. 9 (September 7, 2018): 094103. http://dx.doi.org/10.1063/1.5043107.

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Yiu, C. L., K. T. Tang, and W. G. Greenwood. "Asymptotic Exchange Energy of Heteronuclear Dimers." Journal of Physical Chemistry A 115, no. 25 (June 30, 2011): 7346–51. http://dx.doi.org/10.1021/jp2010925.

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43

Brdarski, Steve, and Gunnar Karlström. "Modeling of the Exchange Repulsion Energy." Journal of Physical Chemistry A 102, no. 42 (October 1998): 8182–92. http://dx.doi.org/10.1021/jp9819893.

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Kiritsis, Elias. "Holography and brane–bulk energy exchange." Journal of Cosmology and Astroparticle Physics 2005, no. 10 (October 27, 2005): 014. http://dx.doi.org/10.1088/1475-7516/2005/10/014.

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45

GILL, PETER M. W., ROSS D. ADAMSON, and JOHN A. POPLE. "Coulomb-attenuated exchange energy density functionals." Molecular Physics 88, no. 4 (July 1996): 1005–9. http://dx.doi.org/10.1080/00268979609484488.

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46

Miura, Hideaki, and Shigeo Kida. "Acoustic energy exchange in compressible turbulence." Physics of Fluids 7, no. 7 (July 1995): 1732–42. http://dx.doi.org/10.1063/1.868488.

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Weere, Srilal M., and J. R. Manson. "Energy exchange in atom-surface collisions." Radiation Effects and Defects in Solids 117, no. 1-3 (September 1991): 221–26. http://dx.doi.org/10.1080/10420159108220617.

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48

Gonze, X., Ph Ghosez, and R. W. Godby. "Polarization Dependence of the Exchange Energy." Physical Review Letters 78, no. 10 (March 10, 1997): 2029. http://dx.doi.org/10.1103/physrevlett.78.2029.

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49

Tsuneda, Takao, Toshihisa Suzumura, and Kimihiko Hirao. "A reexamination of exchange energy functionals." Journal of Chemical Physics 111, no. 13 (October 1999): 5656–67. http://dx.doi.org/10.1063/1.479954.

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50

López-Boada, R., R. Pino, and E. V. Ludeña. "Locality of the exchange energy functional." Journal of Molecular Structure: THEOCHEM 501-502 (April 2000): 35–38. http://dx.doi.org/10.1016/s0166-1280(99)00411-x.

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Journal articles on the topic 'Energy exchange'

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