| In recent years, ground source heat pumps technology has been used widely in manyareas of China in the context of energy saving and emission reduction policy. As a branchtype of ground source heat pumps, groundwater source heat pumps has accounted for50percent market share and become the major ground source heat pumps type in China, withhigher energy efficiency, lower operation cost and broad applicable scope accepted by themajority of users. At the current point, the theoretical studies of groundwater source heatpumps system and the construction technique have been improved gradually, but there arestill many groundwater source heat pumps projects with low efficiency, even some of whichcan’t run at all and have to be forced to shut down in engineering practice. Therefore, whetherthe groundwater source heat pumps projects especially those can not be completely normaloperated will be groundwater environment impact and will produce what kind of impactbecome the focus of the problem. In addition, as the lack of overall development planning andstrict management leading groundwater source heat pumps to free disorder development state,it is necessary to study suitability division and strengthen project supervision. This paperselects Weifang region for the study area and chooses Anqiu center hospital inpatient building,Weifang transit authority dormitory building, Weifang Chenlong hotel and ChangyiHaojiachenghou residential building of four groundwater source heat pumps works asresearch objects on the basis of application status investigation, observes and testsgroundwater quality and simulates groundwater dynamic at the operation stage ofgroundwater source heat pumps, focus on change patterm of groundwater quality, quantityand temperature. The results show that:1. Groundwater quality analysis results show that the concentration of TDS, nitratenitrogen, ammonia nitrogen and some other indicators have changed, to prove thatgroundwater source heat pumps are not completely free from contamination in the currenttechnology conditions; As groundwater quality changing more obviously when the open typegroundwater source heat pumps are used, due to protect the groundwater environmentalsecurity, the government should forbid the application of groundwater source heat pumps inunderground drinking water source protect areas and limit strictly in other functional areas such as the groundwater source of drinking water recharge areas.2. Numerical simulation shows that under whether cooling load or heating load, it takes1~2years for the low or high temperature field to fully restore to the original level. As it’s along cycle of recovery and maybe result in groundwater cold or heat pollution, purerefrigeration or heating groundwater source heat pumps are unfavorable popularized.3. Numerical simulation results show that, when recharge rate is100%, the watertransport path is between the recharge wells and pumping wells and the sphere of influence islimited to around the gang of wells; Recharge rate of75%and50%, the water transport pathof recharge wells and pumping wells as the center to spread around; Recharge rate of25%, agroundwater funnel is formed around the gang of wells, along with the influence radiusexpands to a few kilometers to increase the risk of ground subsidence, so groundwater sourceheat pumps should be forbidden in groundwater overdraft areas and ground subsidence areas,together with strictly controlled in building concentration areas.4. According to the research, low or high temperature field caused by groundwatersource heat pumps spreads faster in the early time, slow down later gradually. In typicalhydrogeology conditions in Weifang area, well spacing less than30meters easy to cause the"heat breakthrough" or groundwater heat pollution problems. In order to improve theefficiency of the groundwater source heat pumps, well spacing usually should not be less than30meters. |
