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Multi-objective optimization of a solar assisted heat pump-driven by hybrid PV
摘要： The role of renewable energy sources becomes more and more important in modern times. Solar energy utilization in the building sector is one attractive solution for covering heating and electricity needs. In this direction, the investigation of a solar heating-electricity production system ideal for building applications is investigated in this study. This cogeneration system includes hybrid PV (or PV/T) collectors and a heat pump which is driven totally (heat and electricity) by the solar collector. The system is designed properly in order to produce net electricity production except for the need of the heat pump. This system is optimized using an innovative multi-objective procedure with heating and electricity production as the objective functions. The optimization is performed in steady-state conditions for seven different working fluids in the heat pumps. The optimum design points for all the working fluids are compared and finally, R32 is selected as the most suitable choice with R1234yf to be the second one. In the optimum design conditions, 10 m2 of hybrid PV collector are able to feed the heat pump and finally 4.33 kWth of heating and 0.53 kWel of net electricity to be produced. The next step in this study is the investigation of the system with R32 for all the winter period in the climate conditions of Athens (Greece). Six different typical days (one for every month from November to April) are examined and the final results are given. For January, which is a representative winter month, it is found that the daily heating and electricity production is 34.9 kWh and 5.13 kWh respectively. Moreover, the mean daily energy efficiency is found 60.53% while the exergy 9.26% for this month.
关键词： Working fluid investigation,Cogeneration,Space heating,Multi-objective optimization,PVT
更新于2025-09-23 15:23:52
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The Potential of Solar Air Heating in the Turkish Industrial Sector
摘要： Transpired solar collector (TSC) systems are simple solutions for the preheating of ventilation air with solar energy. Their performance is a function of several environmental factors, so the climatic conditions of the location play an important role. In this paper, the effect of different climatic zones on the thermal performance of the TSC is investigated. To exclude other sources of influence, the same reference industrial building is examined in four Turkish locations (Antalya, Istanbul, Ankara and Sivas) representing different climatic conditions. RETScreen simulation is carried out for all four regions to obtain the drop of conventional heating requirement in case absorber azimuth of 0°, 45° and 90°. To illustrate the performance, temperature rise, heating energy savings and annual solar fraction are presented. Generally, it can be stated that a location with cold climate and high solar radiation at the same time benefits most from the use of a TSC system. A mathematical correlation has been found showing the solar fraction's dependence on solar radiation and heating degree days. Finally, simulation results have been compared to a set of measurement data from an industrial building's TSC system near Istanbul.
关键词： transpired solar collector,unglazed transpired collector,solar space heating,solar air heating system
更新于2025-09-23 15:21:01
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Proposal and performance analysis of a novel solar-assisted resorption-subcooled compression hybrid heat pump system for space heating in cold climate condition
摘要： Absorption-resorption heat pumps (ARHPs) can efficiently utilize low-temperature solar heat for winter space heating, but are restricted by the relatively weak low ambient temperature adaptability. By combining the different strengthens of vapor compression heat pump (VCHP) and absorption-resorption heat pump (ARHP), a novel solar-assisted resorption-subcooled compression hybrid heat pump system with higher heating capacity under cold climate condition for space heating is proposed. Thermodynamic models for the hybrid system involving two subsystems are developed for performance evaluation under different operation conditions. Feasible high pressure/low pressure (PH/PL) and evaporation temperature/condensation temperature (Te/Ta) ranges for the hybrid system are revealed for component design. Based on that, performance evaluation indices like total coefficient of performance (COPtot), primary energy ratio (PER), primary energy saving ratio (PESR), coefficient from solar irradiation to heating capacity (SCOP) are investigated in terms of different PH/PL and Te/Ta values. The results showed that for the base-case, the above indices are 2.41, 1.66, 0.35 and 1.21, respectively. In addition, heat source temperature demand, heating capacity and ambient air temperature need of the hybrid system are compared with those of the conventional absorption heat pump (AHP), single ARHP and single VCHP under the same operation conditions. The results show that the hybrid system can extend the operation heat source temperature to above 72 oC, highlighting the possibility of integrating with common non-tracking solar collectors, and can extend the feasible ambient air temperature to above -20 oC. Moreover, by recovering the sub-cooling heat of VCHP subsystem for ARHP subsystem operation, the hybrid system can lift the heating capacity by over 50% based on the equivalent VCHP system.
关键词： cold climate condition,resorption-subcooled,solar-assisted,hybrid heat pump,space heating
更新于2025-09-19 17:13:59
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Operational performance of a novel heat pump coupled with mini-channel PV/T and thermal panel in low solar radiation
摘要： Here we describe a heat pump system coupled with novel PV/T and thermal panels for space heating in low solar radiation conditions. Existing solar indirect-expansion systems connect the solar panels and evaporator of the heat pump in parallel with the heat storage tank. For our system these three components are instead connected in series, which can stabilize the temperature at the inlet of the evaporator and decrease the inlet temperature of the solar panels, leading to improved energy efficiency and the production of much more thermal energy. The experimental results of this system show that the average electrical, thermal and overall efficiency of the PV/T panels are 15.9%, 33.4% and 49.3%, respectively. The average thermal efficiency of the thermal panels is 60.4%, the COP of heat pump is 4.7 and the room temperature is constantly over 18oC. Based on the experimental results, some improvements are analyzed. We conclude that this operating model can meet the requirement of space heating in low solar radiation environments.
关键词： heat pump,thermal panel,low solar radiation,space heating,PV/T
更新于2025-09-12 10:27:22
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Reference Module in Earth Systems and Environmental Sciences || Solar Energy in Buildings☆
摘要： Solar Energy can be utilized in many ways (e.g., photovoltaics, solar–thermal–electrical systems, solar ponds, and biomass conversion), but in the current chapter only applications associated with covering the heating and cooling requirements of buildings will be discussed. These applications require low or medium -temperature heat and include water heating, either for domestic hot water systems or swimming pools, space heating, and possibly also space cooling.
关键词： Net Zero Energy Buildings,Economics,Passive Systems,Design Methods,Thermal Behavior of Buildings,Buildings,Solar Energy,Solar Collectors,Space Heating and Cooling Systems,Hot Water Systems
更新于2025-09-09 09:28:46