Large Temperature Difference Heat Pump System for Long-Distance Heat Transportation: Experimental Study and Feasibility Analysis

With the increasing depletion of fossil fuels, it is urgent to build an efficient regional heating scheme. Long-distance heating transportation schemes are important for the integration and utilization of low-grade heat resources. It is worth noting that when implementing the long-distance heating transportation scheme, a heat pump system with large temperature differences and high flexibility is required. However, the conventional vapor compression heat pump system is generally based on a single-stage cycle construction, which has the problems of poor heating capacity and a narrow operation range. In this study, a novel large temperature difference heat pump system is proposed. The heat transfer process of the novel heat pump system is serrated, and the pressure ratio of the compressor is similar under different working conditions. Through experimental study, the energy efficiency performance of the system is explored. Taking the conventional heat pump as the comparison object, the annual performance of the system is analyzed. The results show that the novel system can reduce carbon emissions and operation costs by more than 50%.