| The development and utilization of shallow geothermal energy is of great significance to air pollution control and popularization and utilization of clean energy.Ground water source heat pump system as an important technology has been widely used in Anyang City.However,lacking of scientific site selection planning,shortage of potential evaluation,and ignoreance of local water resources management policies during the actual construction and operation had led to the corrosion of the constructed ground water source heat pump system,the reduction of recharge efficiency,and the occurrence of heat penetration with other users,which seriously affected the use of the system.Therefore,it is urgent to study the water resources management regionalization and potential evaluation of groundwater source heat pump system construction,which provide reference for the sustainable utilization of shallow geothermal energy.In this thesis,the groundwater source heat pump system in Anyang City will be carefully studied,our objectives are to analysis the water resources management division by collecting and sorting out hydrogeological data on the basis of previous studies;to study the best well spacing and well distribution mode by selecting typical systems in suitable development areas for numerical simulation calculation;to make the potential evaluation based on comprehensive results of water resources management regionalization,well spacing and well distribution mode determined by water-heat coupling model.The main conclusions are as follows:(1)Combining with water resources management measures,the evaluation index system of water resources management regionalization of groundwater source heat pump system in Anyang city is established through the analyzing the occurrence conditions of shallow geothermal energy in the study area.The first-level evaluation is carried out by using the improved analytic hierarchy process of cloud model,and the second-level evaluation is completed by using GIS spatial analysis function in combination with water resources management division.The groundwater source heat pump system in the study area is divided into three grades,i.e.1)the suitable development area(117.45 km2),2)the restricted development area(459.26 km2),and 3)the prohibited development area(24.02 km2).(2)According to the field data of water source heat pump system,the aquifer water-heat coupling model is established;the temperature field characteristics of different well spacing are simulated by FEFLOW software under the two modes of variable flow rate and traditional constant flow rate.The results show that the probability of thermal breakthrough and temperature change in the variable flow rate mode with the same well spacing are smaller than those in the previous constant flow rate mode,and the best well spacing is 79.75 m and 95.35 m respectively.(3)Through the analysis of the water-heat coupling model of four commonly used well arrangement modes,the results show that the optimal well arrangement mode is isosceles triangle and straight different side pumping and irrigation mode from two angles of thermal breakthrough time and temperature field recovery ability,but considering the influence of construction site and other users,the straight different side is finally determined as the best well arrangement mode.(4)The potential evaluation results show that the average heating potential in the study area is 0.67～1.80×104m2/km2,and the average cooling potential is 0.72-1.92×104m2/km2,with a probability of 90%,which is highly reliable.At the same time,the development and utilization potential calculated by Monte Carlo method at 50%frequency is similar to the traditional method,which can be used as the optimal frequency for potential evaluation of groundwater source heat pump system.The development and utilization of the ground water source heat pump system in the study area saves 2.25×108 kg of standard coal,1.46×108 yuan of energy saving and 3.13×107 yuan of emission reduction.Using the improved analytic hierarchy process of cloud model to calculate the index weight,the results of water resources management regionalization are more comprehensive and reasonable;In the water-heat coupling simulation,the variable flow mode determined according to the weather changes combines HVAC and hydrogeology well,and the determined well spacing and well distribution mode can be better applied to water resources management and potential evaluation.Comprehensive water-heat coupling model and water resources management zoning results are used to evaluate the potential,which provides reference for scientific site selection and rational development and utilization of groundwater source heat pump system. |
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