非均匀温差下埋地双层管道过渡段长度的计算

在管道输送介质过程中，由于管内温度和周围环境温度的差别，热量传播不可避免，温差沿管道的分布是变化 的。引入了温度衰减长度概念，在温差沿管道均匀分布时过渡段长度计算方法的基础上。

Calculation on the length of transition section of pipe in pipe line at heterogeneous temperature difference

During the period while medium transported by pipelines, heat propagation is inevitably due to temperature difference between inner pipeline and ambient temperature, and temperature difference distributed along the pipeline will varies. Through introducing length concept of temperature attenuation and based on a calculation method of transition section length at rectangular distribution of temperature difference along the pipeline, the article puts forward an integral equivalent method for calculation of transition section length of neritic buried pipe in pipe line while temperature difference is varying along the pipeline. According to the formula given, analyzes the effect of temperature attenuation length on transition section length and the effect of other coefficients on the transition section lengths given through two calculation methods. It is shown by relative example that the result of value analysis and theoretical analysis are identical, which provides design basis for the transition section of buried pipe in pipe structure in pipeline engineering.