A coupled heat transfer model of buried pipes and soil at a depth of 2 500 meters is established.Through the simulation on the heat transfer of buried pipes by 2 880 hours(four months),the effects of soil thermal conductivity and geothermal gradient on the heat transfer characteristics of buried pipes and soil temperature.The relationship be-tween the cumulative heat transfer capacity of the buried pipes and the radius of influence is also explored.The results show that an increase in soil thermal conductivity enhances the heat transfer capacity of buried pipes,while the rate of enhancement decreases as the thermal conductivity increases.When the thermal conductivities are 1 W/(m·K)and 4 W/(m·K),the average heat transfer capacities within 2 880 hours are 216.17 kW and 495.92 kW respectively.Similarly,an increase in the geothermal gradient also enhances the heat transfer capacity of buried pipes,with a relatively constant enhancement rate.When the geothermal gradients are 20 ℃/km and 35 ℃/km,the average heat transfer capacities within 2 880 hours are 310.15 kW and 485.55 kW respectively.When the heat transfer conditions are set,the cumulative heat transfer capacity of buried pipes is linearly correla-ted with the volume of the affected soil.
关键词
中深层地热能/地埋管/岩土导热系数/地温梯度/换热影响半径
Key words
middle-deep geothermal energy/buried pipe/soil thermal conductivity/geo-thermal gradient/heat transfer influence radius
维普
万方数据