Suitability Of Soil Source Heat Pump And Simulation Analysis Of Soil Temperature Field In Suzhou Area

With the continuous development and progress of modern society,energy consumption and dependence continue to increase,leading to an increasing shortage of traditional fossil energy sources and irreversible damage to the environment.The concept of sustainable development is proposed.Ground source heat pump is a new energy-saving and environmentally-friendly technology,and it is developing rapidly now.my country’s ground source heat pump technology is in urgent need of popularization and promotion.It is important to understand whether the local hydrogeological conditions are suitable for the establishment of ground source heat pumps.The underground heat exchanger is the core of the ground source heat pump system.Research on how to strengthen the underground pipe The heat exchange performance of the ground source heat pump is of great significance to the promotion of ground source heat pump technology.This paper mainly studies the suitability of ground source heat pumps in Suzhou area,uses the analytic hierarchy process to calculate the combined weights of influencing factors that affect the application of ground source heat pump technology in Suzhou area,and then uses arcgis software to combine data and actual projects to draw maps of each influencing factor,And assign a value to it,and finally superimpose all the layers to obtain a zoning map of the suitability of soil source heat pump technology application in Suzhou area.Subsequently,the COMSOL software was used to establish the geometric model of the single U-shaped buried pipe heat exchanger and the buried pipe group,and brought into the actual boundary conditions in Suzhou,and simulated and analyzed the heat exchange situation and temperature field distribution of the buried pipe heat exchanger.Through the analytic hierarchy process and simulation analysis,the following conclusions are drawn:(1)Based on the "Twelfth Five-Year Plan" topic and the actual situation of Suzhou local hydrogeological data,the thickness of the Quaternary system,the total thickness of the aquifer,the average soil temperature,and the comprehensive Seven soil-source heat pump influencing factors include thermal conductivity,average specific heat capacity,topography,and stratum lithology.By using the analytic hierarchy process,the geological and hydrological conditions in Suzhou area are analyzed,and the combined weights of the seven influencing factors are determined.Using arcgis software to draw the combined weights of the seven influencing factors,and superimpose them to obtain the suitability zones of the site,which are: unsuitable area 47.4km 2,accounting for 11.3% of the total study area;generally suitable zone 57.7km2,accounting for the total The study area is 13.7%;the more suitable area is 185.7 km2,accounting for 44.2% of the total study area;the suitable area is 133.3 km2,accounting for 31.7% of the total study area.(2)Establish a U-tube heat exchanger geometric model similar to the actual project to simulate the heat transfer efficiency of the buried tube heat exchanger under different pipe diameters,soil thermal conductivity,and backfill thermal conductivity.Ground source heat pumps can operate well under the local soil thermal conductivity.Choosing DN32 U-tubes and backfill materials with thermal conductivity in the range of 1.1 to 1.4 can maximize the efficiency of ground source heat pumps.(3)The layout of the pipe group is 11×11,with 121 wells in total.Take the center row to establish a two-dimensional geometric model.When the pipe distances are 3m,4m,5m,and 6m,the soil temperature after 30 days of operation of the pipe group is studied.According to the field distribution,when the pipe spacing is 6m in Suzhou,the heat transfer effect between the buried pipes is the smallest,and the most unfavorable pipe has the highest heat transfer.The soil temperature around the buried pipes has little change,which can prevent the phenomenon of heat accumulation.Happened early.