Performance modeling and analysis of a PVT-HP system with the roll-bond plate as the evaporator during winter conditions

Abstract

In recent years, PVT (Photovoltaic thermal) has attracted extensive attention in social production and daily lives. As a new technology with low-carbon output, environmental protection and energy saving features, the development of PVT will have great application prospects. Buildings need heating in winter, air-conditioning in summer, and, electricity and domestic hot water supply throughout the year. In the face of the diversified energy supply needs of buildings, the existing photothermal and photovoltaic technologies (irrespective of the photoelectric or photothermal conversion efficiency of modules, or the form of single-function module structures and solar energy utilization systems) are unable to meet the requirements of various energy uses of buildings. There are issues too, such as the large footprint of modules. To this end, this paper starts from the perspective of further improving the comprehensive utilization efficiency of solar energy and meeting the requirements of various energy uses in buildings. The authors adopted a combination of experiment and simulation to evaluate the performance of the PVT-HP (Heat pump) system in this study. The PVT-HP system is set up in Dalian and only runs for a short period of time to get necessary operation data. The simulation model uses a self-built PVT module and verifies its accuracy of the model through its operation date. With the proven PVT-HP model, the authors carried out a dynamic simulation and an economic analysis of the operation of the PVT-HP in winter. The operation performance, supply and demand matching, cost and economic payback period of the PVT-HP system were calculated, and the adaptability analysis for different regions are given. Finally, the nominal power of the PVT-HP system was found to be about 2.4 kW per group, the coefficient of performance (COP) in winter was about 4.32, the total winter heating capacity of the system in Dalian reached 6016 MJ, and the power production reached 168 kWh (which can offset 43 % of the total winter power consumption). The system heating performance was good for all regions, and its payback period in Dalian was found to be 6.53 years; the regional adaptability and economy were found to be ideal.