基于ANSYS的直埋热水管道温度场的仿真

Simulation of Temperature Field of Directly Buried Hot-water Pipeline Based on ANSYS

利用ANSYS Workbench 13.0软件,对供回水管同沟敷设条件下,供回水管周围土壤温度场以及供回水管外护管外表面温度场进行有限元仿真模拟。结合仿真结果,对供回水管外护管外表面温度的影响因素进行分析。模拟条件:工作管(螺旋焊缝钢管)外直径为1 220 mm、壁厚为14 mm,供回水管保温层(保温材料为硬质聚氨酯塑料)的厚度为65 mm,外护管(高密度聚乙烯)的厚度为15 mm,管顶埋深为1.6 m,供回水管相邻管壁间距为200 mm,供水温度为130℃,回水温度为70℃。随着与供回水管距离增大,土壤的温度呈下降趋势。供回水管之间的土壤温度比较高,最高达到49.0℃。供回水管外护管外表面温度场基本呈对称分布,对称位置供水管外护管外表面温度高于回水管。供水管外护管外表面最高温度为51.36℃,回水管为49.08℃。供回水管外护管外表面出现最高温度的位置与土壤出现最高温度的位置基本吻合。供回水管外护管外表面温度受供回水管同沟敷设方式、供回水管间距、回水管保温层厚度的影响。供回水管同沟敷设易导致供回水管外护管表面温度提高。增大供回水管间距,有助于降低供回水管外护管外表面温度。降低回水管保温层厚度,将导致供回水管外护管外表面温度提高,在设计计算供回水管保温层厚度时,应综合考虑供回水管的互相影响,不应由于回水温度较低而随意减小回水管保温层厚度。

The finite element simulation of soil temperature field around the water supply and return pipes and the outer surface temperature field of outer protective pipes of the water supply and return pipes under the same ditch laying condition is conducted by ANSYS Workbench 13.0 software. Combined with the simulation results, the factors influencing the outer sur- face temperature of the outer protective pipes of the water supply and return pipes are analyzed. The simulation conditions： working tube （spiral welded steel pipe） outside diameter is 1 220 ram, wall thickness is 14 ram, water supply and return pipe insulation layer （insulation material is rigid polyurethane plastic ） thickness is 65 mm, outer protective pipe （high-density polyethylene） thickness is 15 mm, pipe top buried depth is 1.6 m, adjacent pipe wall spacing between the water supply and return pipes is 200 mm, water supply temperature is 130℃, and water return temperature is 70℃. The soil temperature tends to decrease with the increase of the distance between the water supply and return pipes. The soil temperature between the water supply and return pipes is relatively high, reaching the maximum of 49.0℃. The outer surface temperature of the outer protective pipes of the water supply and re- turn pipes is distributed symmetrically, and the outer surface temperature of the outer protective pipe of the water supply pipe in symmetrical position is higher than that of water return pipe. The maximum outer surface temperature of the outer protective pipe of the water supply pipe is 51.36℃, and that of water return pipe is 49.08℃. The position of the highest outer surface temperature of the outer protective pipes of the water supply and return pipes is basically consistent with the position of the highest temperature in the soil. The outer surface temperature of the outer protective pipes of the water supply, and return pipes is affected by the same ditch laying mode of the water supply and return pipes, the spacing between the water supply and return pipes and the thickness of the insulation layer of the water return pipe. The laying of the water supply and return pipes in the same ditch will easily increase the surface temperature of the outer protective pipes of the water supply and return pipes. Increasing the spacing between the water supply and return pipes will help to reduce the outer surface temperature of the outer pro- tective pipes of the water supply and return pipes. Re- ducing the thickness of the insulation layer of the water return pipe will lead to the increase of the outer surface temperature of the outer protective pipes of the water supply and return pipes. When designing and calculating the insulation layer thickness of the water supply and return pipes, the mutual effect of water supply and return pipes should be considered synthetically, and the thickness of the insulation layer of the water return pipe should not be reduced at random due to lower water return temperature.