Underground Water Source Of ShenYang Li Gong University Research On The Prevention And Control Technology Of Heat Pump Blockage

Taking the groundwater source heat pump project of ShenYang Ligong University as an example,this paper grasps the law of chemical and Biological Clogging of water source heat pump recharge,and puts forward the measures to control the recharge and plugging,and simulate the feasibility of the prediction scheme,so as to solve the operation problem of water source heat pump engineering of the University of science and technology.The research area is located in the first-order region of the alluvial fan of the Luohe River.The groundwater depth is 8.0～12.0m,and the water temperature is 9～11℃.It is suitable for the establishment of groundwater source heat pump project.The ferric ion concentration in the study area is 1.5 to 2.5 mg/L and above,which belongs to areas with high iron content and is prone to blockage in the recharge well.Analysis of the current state of engineering operations and water quality characteristics of the recharging wells may lead to biochemical and gas blockages,and two types of bacteria SRB and FB that cause blockages are detected in the groundwater of the project site.Meanwhile,in areas with high iron content,Fe2+ is The main factor of chemical blockage,Mn2+ does not basically participate in the chemical blockage of the water source heat pump.The permeability of the medium during the reinjection process is reduced.The first is caused by the bacteria itself.When the bacteria is in decline,it is mainly caused by the increase of the extracellular polymer content.In the middle and later stages of the percolation,the bacteria and EPS play a role in the medium.The permeation performance is declining,and it is related to gas generation caused by gas-producing bacteria such as SRB.By XRD diffraction analysis,after the completion of the biological plugging test,insoluble FeS and Fe3O4 were generated,resulting in a decrease in the permeability of the aqueous medium.According to ICP-MS analysis,iron-manganese oxides are formed on the basis of the original sand sample,so the re-plugging is often a composite blockage.This is one of the features of this article.The addition of ClO2 increases the Eh in the percolation sand column and destroys the living environment of SRB,inhibits the reproduction of SRB,promotes the loss of polysaccharides and proteins and leads to a sharp drop in EPS content,and eliminates the combination of H2S and H2S produced in SRB for sulfur respiration and Fe2+ in water.The FeS produced will restore the permeability of the aqueous medium.The addition of NaClO will damage the cell membrane and cause the death of the bacteria.The pH in the soil will increase,the EPS content will decrease,and the recovery of the water flux from the porosity recovery will be relieved.It is proved that adding a chemical reagent to increase Eh and pH value to kill bacteria to relieve bio-clogging is feasible.This is the second feature of this article.Two kinds of compensation schemes were proposed to establish the groundwater flow and temperature model.In scenario I,the amount of water for the recharge well was 28m3/h,and 16 additional recharge wells were needed.The second scenario was based on the indoor experiment to simulate the recharge well volume.35.36m3/h,4 additional irrigation wells are required.Both schemes form a funnel zone and an anti-funnel zone near the pumping and recharging wells during the heating and cooling periods of the water flow model.The influence ranges are about 190m and 210m respectively.In the water temperature model,the maximum groundwater temperature during the simulation period is 17.5 degrees Celsius and the minimum temperature is 5 degrees Celsius.Both of them can meet the requirements of winter heat exchange capacity 5K and summer cooling capacity 7K.The use of groundwater-source heat pump projects in this project for winter heating and summer cooling has little effect on the regional groundwater temperature.The design of the backwater and the placement of wells in the two schemes are relatively reasonable and the scheme is feasible.In this paper,taking Shenyang Institute of Technology as an example,we have mastered the laws of chemical blockage,biological blockage and the control of composite blockage through the investigation of survey data,on-site recharge test and indoor seepage sand column plugging test,and have important theories for the study of water source heat pump plugging prevention.Significance and practical significance provide guidance for relevant research.