The solar photovoltaic/thermal (PV/T) heat pump system is a new type of system that integrates solar PV/T conversion with heat pump technology. It is capable of comprehensive utilisation of solar energy, offers multifunctionality, and has broad application prospects. In this study, a mathematical model of a solar PV/T heat pump system was developed. According to the developed model, the effects of the environmental conditions on the thermal efficiency, net power generation efficiency, total efficiency, coefficient of performance (COP) and electro-thermal ratio of the solar PV/T heat pump system were analysed. The applicable boundaries of the system were determined; and the carbon emission reduction of the system over its entire lifecycle was calculated. The results show that under the reference operating conditions, the system COP can reach 5.11 and that thermal, net power generation, and total efficiencies of the system are 55.7%, 6.57%, and 70.5%, respectively, while the electro-thermal ratio of the system is 0.103. The performance of the system is affected by solar irradiance, ambient temperature, and wind speed in varying degrees. At a given irradiance, the influence of the condensing temperature for the applicable boundary of the system was also analysed. Finally, taking the Lhasa area in China as a case study, the results show that the carbon emission reduction effect was better compared with that of the independent PV system.

中文翻译：

---

太阳能PV/T热泵系统的性能和应用边界分析

太阳能光伏/光热（PV/T）热泵系统是将太阳能PV/T转换与热泵技术融为一体的新型系统。它能够综合利用太阳能，具有多功能性，具有广阔的应用前景。在这项研究中，开发了太阳能光伏/热泵系统的数学模型。根据建立的模型，分析了环境条件对太阳能光伏/热泵系统热效率、净发电效率、总效率、性能系数（COP）和电热比的影响。确定了系统的适用边界；并计算了系统在整个生命周期内的碳减排量。结果表明，在参考工况下，系统COP可达5.11，系统热效率、净发电效率和总效率分别为55.7%、6.57%和70.5%，电热比为系统为0.103。系统的性能不同程度地受到太阳辐照度、环境温度、风速的影响。在给定的辐照度下，还分析了冷凝温度对系统适用边界的影响。最后以我国拉萨地区为例，结果表明，与独立光伏系统相比，碳减排效果更好。