加深式浅层土壤垂直埋管换热性能影响参数研究OA

To study the influence of key parameters on the heat exchange performance of the deepened buried pipe,the article establishes a three-dimensional dynamic simulation model of the deepened buried pipe ground source heat pump system,and simulates the thermal short-circuiting degree and heat exchange rate per unit buried depth of the buried pipe under various parameters.The results indicate that the degree of thermal short-circuiting decreases with the increase of pipe diameter,wall thickness,flow velocity and inlet temperature,and increases with the increase of backfill material and soil thermal conductivity.The heat exchange rate per unit buried depth of the buried pipe(q)increases with the increase of pipe diameter,flow velocity,backfill material and soil thermal conductivity.The q is 13.89～27.94 W/m when the pipe diameter is 20～50 mm,19.28～28.72 W/m when the flow velocity is 0.35～1.15 m/s,18.06～19.78 W/m when the backfill material thermal conductivity is 1.7～3.7 W/(m·K),and 17.89～20.22 W/m when the soil thermal conductivity is 1.55～3.55 W/(m·K).However,the heat exchange rate per unit buried depth of the buried pipe decreases with the increase of wall thickness and inlet temperature.The q is 18.51～19.48 W/m when the wall thickness is 2.0～4.0 mm,and 17.61～20.36 W/m when the inlet temperature is 0～4℃.