Performance Simulation And Economic Analysis On The Hybrid Ground Source Heat Pump System With Supplemental Heat Rejecter Using Water

With the increase of run-year cycle, the running efficiency of unit in traditional GSHPs is getting lower and lower in South China because of the heat imbalance in this place, So a new kind of ground-source heat pump system (GSHPs) with supplemental heat rejecter that is called hybrid ground-source heat pump system (HyGSHPs) has been proposed to solve this problem and its feasibility has been verified in engineering. In order to using the river resources in modern city, the HyGSHPs with supplemental heat rejecter using water is researched in this paper. A building model is established in Changsha City and its hour by hour air-conditioning load is calculated. The model of HyGSHPs and traditional GSHPs are built up using program with the ground heat exchanger, supplemental heat rejecter system and the unit model according to various control methods. These two systems are taken as the central air-conditioning of the building model and their performance is simulated. So their annual energy consumption and costs are obtained and analyzed. The main results and conclusions are as follows:(1) Using HyGSHPs can saves initial investment of system. The initial investment of the HyGSHPs is 479200 yuan which is less than that of the traditional GSHPs by 81000 yuan that accounts for 14.46% of total initial investment.(2) HyGSHPs is also better than traditional GSHPs in system's annual energy consumption. Its annual energy consumption is 37338kW·h which is less than the traditional GSHPs by 3344kW-h that accounts for 8.22% of total annual energy consumption of system.(3) Taking the entrance temperature of unit as the control parameter (Case 3) is the best control. The total annual energy consumption of system under this control is less than the other controls by 200 kW·h～350 kW·h and this is different from the HyGSHPs with supplemental heat rejecter using cooling tower.(4) With the increase of run-year cycle, the advantages of energy-saving of HyGSHPs will be more obvious. In the first and fifth run-year cycle, the annual running costs of HyGSHPs is less than traditional GSHPs by 2675 and 4648 yuan that account for 8.22% and 12.98% of their total annual running costs. The total running costs of HyGSHPs is less than traditional GSHPs by 18004 yuan that accounts for 10.55% of total running costs in the five run-year cycle. So the result shows that this HyGSHPs can solve the problem of heat imbalance in South China and it can be applied in the cities that have enough water.