Research On The Constraint Of Groundwater Source Heat Pump System From Groundwater Dynamics Conditions

As a new type of clean, environmental and renewable energy, shallow geothermal energy has broad prospects of develop and utilization. To abate environmental deterioration and tense circumstances created by fossil energy, to improve the effect of energy saving and emission reduction, shallow geothermal energy has provided an important way. There are two primary methods about the utilization of shallow geothermal energy, ground source pump system and groundwater source heat pump system. groundwater source heat pump system owns better attribute of high efficiency and low running cost with the comparison to ground source heat pump system.Under the condition of aquifer being in the layer where water source has been developed and utilized, groundwater source heat pump system generally applys a cyclic process that would circulate from collection of groundwater to energy exchange, and then to recharge. Through this method, the amount and quality of groundwater would be get guarantee, and the heat energy in groundwater would be utilized reasonably with the process of project. The stability, efficiency and cost of "collection-exchange-recharge" system that is relied on by groundwater source heat pump system would bring about some influence on groundwater source. This kind of influence is always restricted by groundwater dynamics conditions.Based on 8 groundwater source heat pump system projects in Anhui province, we have already researched and monitored the influence of groundwater from groundwater source heat pump system's stability efficiency and cost, The Jing County Hospital and Li Xin County People's Hospital are applied in this thesis as two examples, selected from 8 projects. By water-heat transfer principle, TOUGH2 software could be used to establish water-heat transfer simulation model. Quantitative analysis of influence extent, range and process coming out from groundwater flow dynamic field and temperature field would be the second step. And the next step is the purpose of this thesis, research on the constraint of groundwater source heat pump system from groundwater dynamic conditions.The result of research indicate that there would be lots of water loss when groundwater source heat pump system is constructed and working, such as loss of construction, loss of washing wells, loss of circuitry, loss of recharge, and water flowage. Thereinto loss of washing wells owns the maximum proportion. Loss of washing wells in Jing County Hospital reaches a 33.3% proportion in water loss. Loss of washing wells of Lin Xin County People's Hospital takes a 85.7% proportion in water pumpage. Aquifer permeability coefficient has a close relation with influence between heat pump system and groundwater source. Aquifer permeability coefficient of Jing County Hospital is 25m/d. Aquifer permeability coefficient of Lin Xin County People's Hospital is 7m/d. The amount of recharge water loss of Jing County Hospital is less 2% than Lin Xin County People's Hospital. In the end of system operation cycle, Jing County Hospital's pumping wells level influence scope is less 16.55km2 than Lin Xin County People's Hospital's, and recharge wells level influence scope is less 0.25km2 than Lin Xin County People's Hospital's. Heat pump projects'water loss leads to postpone water level recover. The less aquifer permeability coefficient is, the more obvious retard is. When the groundwater source heat pump system is working, it would have some effect on groundwater temperature field.