Energy, economic and environmental analysis of a photovoltaic-thermal integrated dual-source heat pump system under a system coefficient of performance − based switching strategy

• Published in: Energy and buildings Vol. 323; p. 114759
• Main Authors: Sang, Xuejing, Qu, Minglu, Yan, Nannan, Li, Zhao, Liu, Hongzhi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2024
• Subjects: Economic analysis; Energy analysis; Environmental analysis; Heat pump; Photovoltaic-thermal; Switching strategy; Switching strategy; Energy analysis; Economic analysis; Photovoltaic-thermal; Environmental analysis; Heat pump
• ISSN: 0378-7788
• DOI: 10.1016/j.enbuild.2024.114759

•System coefficient of performance (COPsys) − based switching strategy is proposed.•Energy, economic and environmental (3E) analysis method is used.•The performance under COPsys-based strategy is better than under conventional one.•Average COP* under COPsys-based strategy is improved by 13.36%. The photovoltaic-thermal integrated dual-source heat pump system can offer performance improvement by addressing the limitations of a single heat pump system, which not only improves energy efficiency and system performance but also reduces pollutant emissions. However, the operational performance of the system is significantly affected by different switching strategies between two heat sources, which has not been given adequate attention from researchers. Therefore, this study introduced a system coefficient of performance − based switching strategy, which can alternate between air-source heat pump and solar water heat pump modes to make full use of air and solar energy, to optimize the operation of the photovoltaic-thermal integrated dual-source heat pump system and compare with the conventional water temperature of the heat storage tank − based switching strategy. A TRNSYS model of the system was developed and validated, and the simulated results demonstrated the better performance of system coefficient of performance − based switching strategy in energy, economic and environmental perspectives. The average photoelectric and photothermal conversion efficiency under system coefficient of performance − based switching strategy were higher than those under water temperature of the heat storage tank − based switching strategy by 1.1 % and 4.0 %, respectively, with average modified coefficient of performance of 7.43 and 6.55. Furthermore, the system not only achieved savings of 5.63 % in annual electrical cost and 5.33 % in yearly operational cost but also reduced standard coal by 19.25 kg and total pollutant emissions by 242.55 kg per year under system coefficient of performance − based switching strategy, compared to water temperature of the heat storage tank − based switching strategy.