不同季节埋地热油管道周围土壤温度场数值模拟

埋地热油管道周围土壤温度场是随时间变化的非周期性非稳态温度场，建立埋地管道周围土壤温度场的非稳态传热模型，对不同季节埋地热油管道周围土壤温度场非稳态传热规律进行数值模拟。分析表明，不同季节温度条件下管道周围土壤温度场分布差别很大，管道有、无保温层土壤温度场分布明显不同。管道有保温层条件下，管道周围土壤温度场呈半圆形曲线分布，在冬季等温线沿管道正上方分布，在夏季等温线沿管道正下方分布；管道无保温层条件下，管道周围土壤温度场呈近似椭圆形分布。这主要是由于土壤热阻的存在温度波在传导过程中具有迟延性，管道周围土壤温度场受管道散热影响，两条等温线出现重合所致。通过对埋地热油管道非稳态传热因素的研究分析，为管道安全、经济启输、节约能源提供参考。

Numerical Simulation of Soil Temperature Field Around Buried Hot Oil Pipelines in Different Seasons

Soil temperature field around heat oil pipelines is a non-periodicity and unsteady temperature field that changes with time. In this paper, unsteady heat transfer model of soil temperature field around buried pipelines was established, unsteady heat transfer law of soil temperature field around buried pipelines in different seasons was simulated. Analysis shows that temperature distributions of soil temperature field around the pipelines in different seasons are different, distributions of soil temperature field around the pipelines with and without thermal insulation layer have markedly difference. Soil temperature field around the pipeline with insulation layer appears semicircle distribution, isotherm in winter is above along the pipes and isotherm in summer is under along the pipelines. Soil temperature field of pipe without insulation layer appears nearly elliptic distribution. This is mainly due to existence of soil thermal resistance and delay of temperature wave to result in two isotherms coincidence under effect of heat dissipation of pipes. The factors analysis of unsteady heat transfer in soil around heat oil pipelines can provide some references for pipes security and energy saving.