Optimization Of Heat Exchange Efficiency Of Underground Water Source Heat Pump System In Tiexi Brilliance BMW Factory

Energy problem is a hot research topic in human life.Groundwater source heat pump,as a new energy-saving technology,is the key issue of water source heat pump project to improve the heat transfer efficiency.In this paper,the new heat pump system of BMW Brilliance engine plant in Tiexi Brilliance is taken as the research object.It is found that there are some problems such as plugging,water temperature overheating and poor water quality during the trial operation.According to the geological survey report of the study area,The iron content in the groundwater is very high,which will lead to blockage in the iron recharge well.At present,the heat insulation device in the water pipe is not perfect enough,which makes the water temperature in the water pipe higher in summer,reducing the heat transfer of the water source heat pump system In addition,due to the distribution of newly-added pumping wells in the old scheme,the pumping water temperature and water quality are affected by Xihe River,which will affect the heat exchange effect of water source heat pump system and increase the operational safety hazard of water source heat pump system.In view of these problems,this paper takes the Tiexi Brilliance BMW water source heat pump system project as an example,through indoor sand column simulation recharge test,analyzes the iron and manganese ion content plugging situation of iron and stainless steel injection wells,to provide material selection recommendations;Water pipes in the soil to simulate the heat dissipation,analysis of different insulation materials,the thickness of the insulation effect of different thermal insulation layer to provide a reference for optimization;established water flow,water temperature and water quality mathematical model to simulate the new and old wells plan water level and water temperature The trend of change,combined with other factors to provide the best solution to improve the heat transfer efficiency of the water source heat pump project system.The main contents of this paper are as follows:(1)Indoor recharging experiments were conducted to compare the effects of different concentrations of Fe-Mn ions in backwashing water.By comparing the effects of stainless steel pipe and iron pipe recharging wells,The project provides recycle well selection advice.The results showed that,just increasing the concentration of manganese did not affect the plugging situation.The plugging in the recharge well was mainly caused by iron ions.As the concentration of iron ions increased,the plugging of the iron recharge well was more likely.No well plugging occurred.Therefore,the project proposed the use of stainless steel injection wells where funding permits.(2)The thickness of insulation material and insulation layer are simulated,the model is set up by Gambit software,the grid is divided and the boundary conditions are set,the eight different conditions of the two models are simulated,the simulation results show that different materials,different materials Due to the different thermal conductivity and thickness of insulation layer,the heat transfer gradient between the fluid temperature in the water pipe and the soil is very different,but the actual project is not the lower the heat transfer coefficient,the lower the thickness Thick material is the best,but should be combined with the actual project,the selection of the most economic benefits of the most reasonable materials and economic thickness(3)Establishing water level,water temperature and water quality model,using Feflow software to simulate the scope of Brilliance BMW underground water source heat pump project,running for 5 years,verifying the rationality and reliability of water intake at old and new points,,Water temperature and water quality.It is found that the temperature,water level and water quality of the rewatered water during the five-year plan are more reasonable than the old one.Comparing the simulation results of the end of the heating season and the end of the cooling season in the last year,The radius of influence and the migration of pollutants are better than the old program,reflecting the rationality of the new well drilling plan.(4)Taking the conditions of hydrogeology,insulation material,construction load,construction environment and wellsite as the evaluation indexes,this paper constructs the judgment matrix of the evaluation indexes in the two schemes of old and new,from the perspectives of economic benefit and environmental benefit,1-9 scale method to compare each other,through the matter element model to calculate the new program evaluation results as"good" to determine the new program for the optimal program.