Research On Irrigation Wells Arrangement And Aquifer Thermal Breakthrough Of Deep Geothermal Water Heating

Deep geothermal water heating system is a kind of renewable resources for new heating technology,accurate analysis on the velocity field and the temperature field around the return well has important influence on the effective utilization of energy supply about return water.Based on the deep analysis of the heat conduction mechanism of the water bearing layer,the model assumptions and the limiting conditions are proposed.The relationship between seepage velocity field and temperature field is analyzed.Thermal breakthrough parameters affecting the efficiency of geothermal water heating in middle and deep layers are proposed and calculated.The effect of seepage velocity field on thermal breakthrough is analyzed and summarized.The influence of hydrogeological parameters,Ima,heat load and natural hydraulic gradient on thermal breakthrough was analyzed.The results show that the permeability has little effect on the thermal breakthrough in the hydrogeological parameters,but with the decrease of the porosity and the thickness of the hot zone,Thermal breakthrough phenomenon gradually deteriorated.The horizontal distance and arrangement of the middle and deep geothermal water pumping wells are determined.Based on the theoretical research results,the time of thermal breakthrough is analyzed and solved.Large spacing can inhibit the phenomenon of thermal breakthrough;large pumping flow and large pumping temperature difference will accelerate the process of thermal breakthrough,plus a big breakthrough.The results show that the spacing between pumping wells should be controlled at 60m-200m,and the pumping wells should not be placed in the direction paralleled to the hydraulic gradient.The influence of different well patterns and periods on the geothermal water heating system in middle and deep layers is studied.Discusses the disturbance and influence on layer temperature of pumping wells(Group)and recharge wells(Group)from recharge well arrangement,pumping well temperature difference and thermal break extent,put forward to that the temperature between pumping well and the thermal properties as the main evaluation index to judge breakthrough deep hot water heating system is reliable.This paper designs the suitable layout of the pumping well and the operation mode of the geothermal water heating system in the deep geothermal water heating project.The results show that the coupled model can describe the basic characteristics of geothermal water and temperature field.The above research results have guiding significance for the existing engineering optimization and the new project design and construction.