Urban heating energy consumption in northern China accounts for 40% of total building energy consumption. In traditional central heating system, heat transfers from primary network (130°C/70°C) to secondary network (60°C/45°C) through heat exchangers in substations. In this paper, by introducing heat engine, heat pump and considering obtaining heat from environment, a new heat adaptor is built and the best system can be deduced out after thermodynamic optimization through extremum principle. The preliminary results indicate that when the return water temperature of primary network equals the ambient temperature, the heating capacity reaches the maximal value, which increases by 40% compared to absorption heat exchange system. Thus the thermal performance of existing heating systems can be evaluated.
Zhang, Y., Zhang, Y. P., Shi, W. X., & Wang, X. (2015). Application of heat adaptor: thermodynamic optimization for central heating system through extremum principle. Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics, 36(5), 941–944.