A new system of energy tower heat pump combined with boilers and solar energy

In winter, the antifreeze is used to prevent icing when the air temperature is below 0℃ which increase the operating cost of the energy tower heat pump and causes environmental pollution. To address this issue, this paper proposes a combined heating system that supplemental heat when winter ambient temperatures drop below 4°C. Four supplemental heating methods adopted: energy tower heat pump with boiler of condenser-side, energy tower heat pump with boiler of evaporator-side, air-source heat pump and boilers, and energy tower heat pump with solar energy. In order to verify the effectiveness of these four systems, thermodynamic analysis is carried out in the heating season compared with the old system (just with boiler heating) through a hotel case in HuaiHua City, Hunan Province. The results demonstrate that average COP of these four heating methods is 1.595,1.904,1.907, and 1.891. The average exergy efficiency of these four heating methods is 4.4%,10.2%,11%,11%. Through thermodynamic analysis, it is found that the supplemental heating method with boiler of condenser-side is inefficient. Therefore, excluded the energy tower heat pump with boiler of condenser-side supplemental heating system, the economic analysis shows that these three heating methods save 185100, 184800, and 187300 RMB of a heating season. Based on the above analysis, the energy tower heat pump with solar energy supplemental heating system is the optimal heating systems. This paper provides a good theoretical basis for the follow-up renovation and new construction of HVAC system