Study On The Water Heat Balance Of A Groundwater Source Heat Pump System In Tibet

By field investigation of a groundwater source heat pump system hydrogeological environment in Tibet,based on 72 hours of group well irrigation test,obtained the preliminary results of the system's operation process water thermal balance:(1)The system will extract groundwater by heat exchanger absorption(or release)heat back into the ground,the water consumption is less,but due to the hydrogeological conditions of the aquifer,the aquifer penetration coefficient will eventually decay to about 10m/d,long-term operation may eventually lead to recharge blockage.(2)By analyzing and calculating the change of groundwater head during the long-term operation of the system,the results show that the difference between the end of the operation of groundwater head in the range of-2m to 1m in a period(90 days),shows that the system can basically ensure the equilibrium and stability of the irrigation water.(3)By monitoring the groundwater temperature running during the system,the author calculates and analyzes the change of groundwater temperature in the long-term operation of the system,and the results show that the water temperature at the end of the system operation,pumping wells 1 and 2,decreased by 3.607 degrees C and 1.546 degrees C respectively,indicating that the long-term operation of the system will produce heat through the region and change the groundwater temperature.(4)Through the water chemistry analysis of groundwater before and after the operation of the system,the author compares the water quality changes before and after the test,and thinks that the system will increase the content of nitrates and fluoride in groundwater,and cause pollution for a long time.