Recent advances in direct expansion solar assisted heat pump systems: A review

Shi, Guohua; Aye, Lu; Li, Dan; Du, Xianjun

doi:10.1016/j.rser.2019.04.044

Cited by 97 publications

(26 citation statements)

References 71 publications

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“…En un sistema de refrigeración el condensador influye notablemente en su rendimiento, es necesario conocer las características, variables de diseño y operación del intercambiador de calor y del refrigerante utilizado. Shi et al [20] resumieron los recientes avances en sistemas DX-SAHP a nivel mundial. Los resultados indican que las configuraciones de condensadores no son tantas como las de un colector/evaporador debido a que es un intercambiador de calor convencional.…”

Section: Revisión Del Estado Del Arteunclassified

Análisis del rendimiento termodinámico de una bomba de calor asistida por energía solar utilizando un condensador con recirculación

Quitiaquez¹,

Simbaña²,

Caizatoa³

et al. 2020

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La presente investigación estudia una bomba de calor de expansión directa asistida por energía solar con un sistema de recirculación de agua. Los intercambiadores de calor utilizados fueron un colector/evaporador de cobre de 0.75 m2 y un condensador en forma de serpentín construido en tubería de cobre de 2.49 m de longitud y 8 espiras, inmerso en un tanque con 5 litros de agua. Para la recirculación del agua, se utilizó una bomba centrífuga de 20 L/min a 110 V. El compresor instalado es de velocidad variable a 12-24 V DC que utiliza R600a como fluido de trabajo. El dispositivo de expansión utilizado fue una válvula electrónica. Las pruebas experimentales se desarrollaron para una configuración con recirculación y sin recirculación de agua, considerando condiciones climáticas similares. De esta manera, se puede establecer cuál es la configuración que brinda un mayor rendimiento en el sistema. Para la obtención de datos de radiación solar, velocidad del viento y temperatura ambiente se empleó una estación meteorológica WS-1201. Este sistema proporcionó agua caliente sanitaria, a 45 °C en un tiempo entre 40 a 50 minutos dependiendo de las condiciones climáticas. El COP máximo del sistema con recirculación fue 9.83 un 8.04 % mayor que el sistema sin recirculación. El tiempo de calentamiento tardó 10 minutos menos para el sistema con recirculación, 16.67 % menos que al utilizar el sistema sin recirculación.

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Section: Revisión Del Estado Del Arteunclassified

Análisis del rendimiento termodinámico de una bomba de calor asistida por energía solar utilizando un condensador con recirculación

Quitiaquez¹,

Simbaña²,

Caizatoa³

et al. 2020

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“…The PV-T collectors working with refrigerants are successfully integrated with the heat pump systems for improving the performance of both PV-T collectors as well as the performance of heat pump systems. [7][8][9][10] Many research investigations have been reported on the performance of heat pump system using PV-T collectors. Ji et al 11 investigated the performance of a heat pump using PV-T collector evaporator under the climatic conditions of China.…”

Section: Introductionmentioning

confidence: 99%

Photovoltaic thermal collector assisted heat pumps using environment-friendly working fluids

Ammar

Sopian

Mohanraj

2020

Proceedings of the Institution of Mechanical Engineers, Part E:

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In this research, a photovoltaic-thermal collector assisted heat pump has been developed and tested its performance under the tropical climatic conditions of Malaysia. The refrigerants such as, R134a and R1234yf were selected based on its thermodynamic and thermo-physical properties. The temperature of the photovoltaic module was theoretically predicted under the influence of tube diameter, tube spacing and refrigerant mass flow rate. Further, the energy performance of the photovoltaic-thermal evaporator and the heat pump system are investigated experimentally. Finally, the economical feasibility of the photovoltaic-thermal collector evaporator was assessed for the period of 20 years. The results showed that, the tube spacing and diameter of the copper tubes used in the photovoltaic-thermal evaporator/collector using R134a and R1234yf were optimized to 80 mm and 12.7 mm, respectively. It was observed that, during the clear sunny day, the average photovoltaic module temperature was reduced to 30.9 °C under the influence of panel cooling using refrigerant. The output of the panel was enhanced by 21%–44% with increase in solar radiation from 400 W/m2 to 1000 W/m2. The coefficient of performance of the heat pump was varied from 4.8 to 6.84 with an average coefficient of performance of 5.8 during clear sunny days. The life cycle economic analysis indicated that, the photovoltaic-thermal collector evaporator assisted heat pump has a payback period of 3 years, whereas the reference photovoltaic system has a payback period of 8 years.

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“…Modern studies are aimed at the prospects of using secondary low-potential heat resources [8], the creation of high-temperature heat pumps [9], the use of heat pipes in geothermal heat pump systems [10], the creation of combinations of heat pumps with solar energy utilization systems [11] and absorption-compression pumps [12]. The urgency of addressing the problems of the recuperation of secondary energy recourses is due to the fact that the industrial sector consumes one-third of the world energy with subsequent its transformation into thermal energy at the level of 50% [7].…”

Section: Introductionmentioning

confidence: 99%

Determination of the parameters of the recovery systems of heat potentials of streams of the gas-steam media

Shevchenko¹,

Sokolenko²,

Stepanets³

et al. 2019

Ukr. food j.

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Introduction. The paper concerns the determination of the relations of energy potentials in mass flows of gas and steam-gas systems and their changes in thermodynamic transformations and regeneration possibilities. Materials and methods. Researches are presented in the form of phenomenological generalizations on the basis of the laws of chemistry, thermodynamics with thermochemical calculations based on Hess's law. Results and discussion. Transformation of incoming gas streams used as the primary sources of chemical energy potentials with conversion into thermal energy is accompanied by losses at the level of heat of condensation of the formed vapor phase. Vapor-gas mixtures are generated in the processes of drying, aeration of grains for germination, in systems of aerobic fermentation processes, in the aeration of industrial wastewater, etc. The course of such processes takes place in thermodynamic parameters, which do not correspond to similar characteristics of the environment, which is accompanied by energy losses at the levels of difference between their enthalpies. From this point of view, an important component of such gas-steam mixtures is the steam fraction of water, since it carries the thermal potential of vaporization. The article discusses the ratio of parameters of material and heat flows, provides information that the energy potential of condensation of the vapor phase in products of combustion of gases is close to 10% of their calorific value. The estimation of the prospects of the application of heat pipes in heat recovery systems by the creation of closed energy circuits is evaluated. It is shown the possibility of combining heat exchanging surfaces of cooling and heating with heat pipes, which achieve the same parameters of the temperature of evaporation and condensation of intermediate thermal agents, the thermodynamic parameters of the latter in terms of the possibility of their application in the systems being created are given. With the presence of energy converters in the form of compressors and gas-expansion machines, the recovery systems are converted into local heat pumps. The use of methane, ethane, propane and butane as the primary source in the formation of water vapor is carried out in quantities corresponding to their chemical formula, depending on the ratio of the number of atoms of carbon and hydrogen. Recuperative recovery of the energy of the output vapor-gas mixture is expedient to carry out in the direction of the input air flow in systems with an intermediate coolant and implementation of heat exchange processes with the simulation of effects of thermal pipes or with the addition to the schemes of heat pumps. Conclusions. The schemes of thermodynamic processes confirm the possibilities of applying the proposed thermodynamic transformations.

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Recent advances in direct expansion solar assisted heat pump systems: A review

Cited by 97 publications

References 71 publications

Análisis del rendimiento termodinámico de una bomba de calor asistida por energía solar utilizando un condensador con recirculación

Análisis del rendimiento termodinámico de una bomba de calor asistida por energía solar utilizando un condensador con recirculación

Photovoltaic thermal collector assisted heat pumps using environment-friendly working fluids

Determination of the parameters of the recovery systems of heat potentials of streams of the gas-steam media

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