Comparison of mechanical vapor recompression technology for solution regeneration in heat-source tower heat pumps

Abstract

Solution regeneration of the heat-source tower is significant to guarantee the normal operation of the heat-source tower. Mechanical vapor recompression system is an efficient system for evaporation of solution. In this paper, mechanical vapor recompression system is applied to regenerate solution of heat-source tower. To clarify the merits of mechanical vapor recompression solution regeneration system, several typical solution regeneration systems are modelled. As a result, mechanical vapor recompression shows 35.7%, 73.5% and 91.2% energy saving compared to air-driven heat pump, three-effect evaporating system, and single effect evaporating system, respectively. Furthermore, a heat-source tower heat pump with solution generation system is installed in a typical building in Yangtze river region. The whole heating season performance is simulated to find the effects of different solution regeneration system on the whole heat pump system. As a conclusion, the seasonal coefficient of performance of heat pump is decreased 1.6% by mechanical vapor recompression regeneration system. Comparatively, the seasonal coefficient of performance of heat pump is decreased 2.6%, 4.2% and 10.0% by air-driven heat pump, three-effect evaporating system, and single effect evaporating system, respectively. Practical application: Solution regeneration systems for heat-source tower heat pump systems have been applied in building projects especially in hot summer and cold winter zone in China based on previous investigation. A heat-source tower heat pump system combined with heat pump solution regeneration system has been applied in an office building in Changsha, Hunan Province in China. And its practical operation energy consumption has been reduced obviously compared with traditional single effect evaporation system. Therefore, it is of vital importance to demonstrate the operating performance of different solution regeneration systems applied in heat-source tower heat pump systems in building.