Exergy analysis of solar thermal energy utilization for buildings: comparison between Multiple source Multiple use Heat Pump (MMHP) and Solar Water Heater (SWH) systems for winter season (original) (raw)
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Exergetic Studies on Domestic and Industrial Solar Water Heaters
International Conference on Information Engineering, Management and Security 2014, 2014
For a Solar Water Heater ,solar energy coming from sun in the form of solar radiations in infinite amount, when these solar radiations falls on any absorbing surface, then they gets converted into the heat, this heat is used for heating the water. Present study based on exergy theory. Exergy analysis is conducted with an objective of providing methods to save cost and to increase the efficiency of solar water heater. The calculation of exergy losses is also done. To optimize and allocate losses in energy systems exergy analysis has been widely used. Exergy is the indication for loss of available energy due to the creation of entropy in irreversible thermal systems or thermodynamic processes. The exergy loss in a system or process component is decided by multiplying the absolute temperature of the surroundings by the entropy increase. Exergy is defined as a maximum useful work that can be done by a system interacting with an environment. In the design, simulation and performance evaluation of energy systems Exergy analysis has been widely used.
Performance characteristics and energy–exergy analysis of solar-assisted heat pump system
Building and Environment, 2008
In this study solar-assisted heat pump (SAHP) system with flat plate collectors was investigated experimentally and tested for domestic space heating. SAHP system was located in a test room with 60 m 2 floor area in Firat University, Elazig (38,411N, 39,141E) Turkey. The experiments were performed in heating season of January 2003. The coefficient of performance of the SAHP system was calculated. The system COP of the SAHP was obtained as 3.08 while the exergy loss of the solar collector was found to be 1.92 kW. The second law efficiency of the compressor, condenser, evaporator and solar heat exchanger in SAHP system were evaluated 42.1%, 83.7%, 43.2% and 9.4%, respectively. The first law efficiency and exergetic efficiency of the whole system are found to be 65.6%, 30.8%, respectively. Consequently the energy and exergy loss analysis results show that the COP increase when the exergy loss of evaporator decrease.
Journal of Cleaner Production , 2012
The serious environmental degradation of our planet in the past century and the limitation of supplies of conventional fuels have led humanity to search for new energy forms. The housing sector has a big environmental impact and it makes a good candidate for changes to be implemented in order to make steps towards a sustainable society. This study deals with the exergy analysis and the Life Cycle Assessment (LCA) of solar systems for space heating, cooling and hot domestic water production. These systems will be applied to a residence in the wide Thessaloniki area, in Northern Greece. The analysis is based on the given energy needs of an average house. Furthermore, a photovoltaic system (PV) will be used for electricity production. Besides Solar energy, the existing geothermal field will be utilized via heat pumps. The system is designed to exploit solar and geothermal energy and an exergy analysis of the different elements of the system is performed so that improvements can be achieved in its efficiency and its cost be reduced. It has been shown that the exergy efficiency of the solar systems and the geothermal system are relatively low. Since almost all of the environmental impacts of the renewable energies are connected to the manufacturing of the devises for their utilization, the environmental impacts will be analyzed only at the manufacturing stage. The use of Life Cycle Assessment (LCA) will be used. It has been shown that the use of solar cooling has the highest environmental impact. This analysis applies for all regions since the energy needs could be adjusted and the solar radiation of that region taken into consideration.
Experiments on a solar-assisted heat pump and an exergy analysis of the system
Applied Thermal Engineering, 2002
In this work a experimental study of a solar assisted heat pump with direct expansion of the refrigerant within the solar collector, is presented. The maximum exergy efficiency, defined as the ratio of the outlet to the inlet exergy flow in every component of the heat pump cycle, is determined taking into account the typical parameters and performance coefficients. The results of this exergy analysis point out that the main source of irreversibility can be found in the evaporator of the heat pump (that is, the solar collector) emphasizing that incoming solar radiation is not used to full advantage in this piece of equipment. Ó
Investigation of Performance of Solar-Assisted Heat Pump Systems: Muğla Example
Mugla Journal of Science and Technology, 2018
In this study, the combination of solar thermal systems with heat pump has been investigated numerically. The potential utility of the collectors is found by comparing heat pump systems with combined systems. All simulations for the Muğla province were made using the POLYSUN program. The simulated systems are designed to meet the demand for hot water and residential heating of single-dwelling houses. The results of this study show that the seasonal performance factor of the system increases as the collector field added to the air source heat pump system increases. However, in the systems where the heat demand is met, the heating effect coefficient of the heat pump (COPHP) decreases. In this system, solar energy is used to meet the need for hot water, while also supporting housing heating. However, it has been determined that the heat pump should be selected at a sufficient capacity because the increase in the number of collectors by selecting the heat pump at the insufficient capacity cannot meet the demand. However, it has been determined that the heat pump should be selected at a sufficient capacity because the increase in the number of collectors by selecting the heat pump at the insufficient capacity cannot meet the demand. In the systems where the heat demand cannot be met, the heating effect coefficient after 2 collectors is found to be constant. Collectors used in excess of 2 collectors are closed when there is no need for them. However, it supports heating in winter.
Renewable energy, Exergoeconomic, Cogeneration system, Solar power Increasing environmental pollutions and the expense of fossil fuels necessitates employment of efficient instruments and easily producible clean sources as abasic solution to this problem. Cogeneration systems are used for their high performance with a performance of approximately eighty-five percent Cogeneration production system with renewable energy source is the best solution to fuel suitable and high cost Amon all renewable energy sources, use of solar power is of interest. Solar power is the best choice because it's free and clean. This project illustrates the analyzed exergy and eregyeconomic simulations of solar hybrid cycle. Thermo economic and exergoeconomic analysis where used in this research, with exergoeconomic we can analyze cycle cost, payback period and exergy performance. Case study for this project was a building with 480 m² or square meters area in Zahedan, Iran. In this study, a small scale hybrid solar heating, cooling and power generation set-up including solar collector, screw expender auxiliary heater, adsorption chiller, etc., was proposed and extensively investigated.
Energy and exergy analyses of an integrated solar heat pump system
Applied Thermal Engineering, 2014
h i g h l i g h t s An integrated system is analysed using renewable energy source which can be used in textile industry. Energy losses and exergy destructions are calculated at all major components. Energy and exergy efficiencies of all subunits, subsystems and overall system are determined. A parametric study shows the effect of environment and operating conditions on efficiencies. Solar energy for heating in textile industry is efficient and environmentally friendly.
Applied Thermal Engineering, 2011
Solar source heat pump systems present tremendous environmental benefits when compared to the conventional systems for residential applications. In addition to not exhausting natural resources, their main advantage is, in most cases, total absence of almost any air emissions or waste products. In order to investigate the performance of a solar source and energy stored heat-pump system in the province of Erzurum, an experimental setup was constructed, which consisted of twelve flat-plate solar collector, a sensible heat energy storage tank, a water-to-water plate heat exchanger, a liquid-to-liquid vapor compression heat pump, water circulating pumps and other measurement equipments. The experiments were carried out from January to June of 2004 and, the collector efficiency (h c), the heat pump coefficient of performance (COP) and the system performance (COPS) were calculated. In these months performed of the experiments, the outdoor temperature range varies from À10.8 C to 14.6 C. This study shows that the system could be used for residential heating in the province of Erzurum having the coldest climate of Turkey.
Exergoeconomic optimization of solar heat pump systems of heat supply
E3S Web of Conferences, 2020
In this paper, there is analyzed the results of exergy economic optimization of heat-cooling supply in building by using the solar heat pump system. It is possible to realize a system having high reliability in operation of the system. The solar heat pump system according to the present technical decision has high energy efficiency while ensuring reliability, and is useful as a domestic air conditioning and heating water heater. It can also be applied to uses such as industrial heating and cooling devices.
Performance evaluation method of solar-assisted heat pump water heater
Applied Thermal Engineering, 2007
The present study derives a simple linear correlation for the performance evaluation of different solar-assisted heat pump water heater (ISAHP). The correlation was derived from the principle of energy conservation with some simplifications. The correlation is then verified using the long-term outdoor field test data of four different ISAHP. The problems of seasonal repeatability and method of data scattering were examined. From that, a standard performance test method is proposed. The test method suggests that only the measurement of instantaneous solar incident radiation on horizontal surface, ambient temperature, hot water temperature in the storage tank, total mass of water in the storage tank and total power input to the ISAHP are required. It is suggested to select the value of COP at T f À T a,ave = 15°C as the characteristic COP for performance comparison of ISAHP. It is found from the test results that the same performance correlation holds for ISAHP operating with single or dual energy source.