Application And Research Of Ground Source Heat Pumps Technology In Hot Summer And Cold Winter Regions

The main climate characteristics of hot summer and cold winter area were hot in summer and cold in winter, and the humidity was very high, so the load characteristics were different from other climate regions. The building energy-saving season of hot summer and cold winter area was divided with AT values for the first division parameters in this dissertation. After the annual hourly energy consumption simulation of hotels, office buildings and residential buildings in hot summer and cold winter area with the DEST software, this paper described the building’s dynamic load characteristics with the cumulative effect of total load, the variation of load intensity, and the continuity of load.This paper fitted the Ground Source Heat Pump (GSHP) unit’s inlet and out water temperature, the building’s hourly load in to a parametric formula and simulated the operation of GSHP system with the FLUENT software which was controlled by editing the UDF program. This paper also compared the U-tube ground heat exchanger with the equivalent diameter ground heat exchanger based on dynamic load. It could be seen that the maximum deviation of the average temperature of the soil between the U-tube ground heat exchanger and the equivalent diameter ground heat exchanger was0.4℃in cooling and heating season with the GSHP system operating throughout the year in different groundwater seepage conditions. We could also get the conclusion that the average deviation of the outlet water temperature between the U-tube ground heat exchanger and the equivalent diameter ground heat exchanger was0.47℃in cooling season and0.53℃in heating season.The performance of ground heat exchangers would directly affect the performance of GSHP unit. This dissertation established the heat transfer model of geothermal hear exchanger and simulated the running performance of GSHP system which was affected by the groundwater seepage. It could be seen that the seepage was useful to long period operation of GSHP system. When the seepage velocity of the groundwater was equal to31.5m/a, the annual hourly outlet water temperature of the ground heat exchanger which was used in the hotel buildings of Shanghai was about the same.This paper selected Nanjing, Wuhan, Changsha, Chongqing as the typical representative city of the hot summer and cold winter area. Combining with the four cities’ annual load characteristics of different buildings, long period operation characteristics of the GSHP in hot summer and cold winter area were analyzed. The conclusion was placed in three points. On the one hand, the greater the cumulative effect of total load, the higher the temperature of the soil, the greater the heat storage capacity of the soil. On the other hand, the greater the continuity of load, the more uneven the distribution of the temperature of the soil. On the third hand, the greater the variation of load intensity, the higher the highest outlet water temperature of ground heat exchangers in cooling season, the lower the lowest outlet water temperature of ground heat exchangers in heating season.