Simulation research on heat recovery system of heat pump composite pump-driven loop heat pipe

To promote energy-saving potentials of the energy recovery unit under all-year conditions, a composite system combining pump-driven loop heat pipe with heat pump was firstly proposed, and the mathematical models were established. The operating characteristics of the composite system were studied in the whole year and compared with the traditional heat pump heat recovery system. The results show that the heating capacity of the composite system is in line with the heating load in winter. Compared with the traditional heat pump system, the composite system has higher energy efficiency ratio and lower deviation degree of temperature effectiveness in the whole year. The heat pump composite pump-driven loop heat pipe heat recovery system is generally superior to similar system reported in literatures, which indicates that it can replace heat pump system in buildings ventilation.