Comparative study on operating strategies of air source heat pump assisted with large flat plate collector

Large flat-plate solar collector-assisted air source heat pump (LFPSC-ASHP) heating system has been used for winter heating of single buildings in cold and severe regions of China. Our team has studied the construction of the experimental platform and the operation strategy of the LFPSC-ASHP system. Based on the existing system's temperature control strategy, this paper validates Transient System Simulation Program software, simulates the entire heating season, and finds that the operating time of the ASHP on the overall system performance has been consistently overlooked. Specifically, the ASHP running for extended periods during the cold early morning or night leads to a decrease in the ASHP's coefficient of performance, causing a significant economic burden on low-income populations in the severely cold regions of Northwest China. Based on the above situation, this paper proposes a more comprehensive time and temperature control strategy (the comprehensive control strategy), with the primary goal of optimizing the system's economic performance. By using the Genopt software to optimize variables within the system, it aims to achieve the dual objectives of utilizing solar energy while reasonably adjusting the operating times of the solar heat pump and ASHP, thereby reducing system operating costs. By comparing the operating performance of the system under the above two strategies, it is found that the comprehensive control strategy is significantly more economical than the temperature control strategy. The system energy efficiency ratio increases from 3.03 to 3.32, and the power consumption decreases from 5486.9 to 4963.3 kW h, which greatly reduces the operating costs. It provides a valuable strategy for sustainable heating in cold regions in China and even the world.