蜡沉积物有效导热系数对管道传热特性的影响

蜡沉积物有效导热系数的确定是蜡沉积传热计算中的重要内容。在分析非均质二元混合物有效导热系数计算方法的基础上，确定了适合计算蜡沉积物有效导热系数的模型，对比分析了不同蜡沉积物有效导热系数计算方法对管道传热特性的影响。结果表明，蜡沉积物有效导热系数随着沉积物中蜡质量分数的增加而变大；同一蜡质量分数下，并联模型计算的有效导热系数值最大，其次分别为ME2模型、EMT模型以及串联模型，ME2模型和EMT模型的计算结果较为接近；EMT模型的假设条件与实际蜡沉积物的结构分布相似，因此推荐使用EMT模型计算蜡沉积物有效导热系数；EMT模型和M关联式计算所得的管段沿线温度非常接近，EMT模型所得的管道径向温度梯度高于M关联式的计算结果；总体来看，EMT模型和M关联式所得的管道传热计算结果差异较小，但M关联式应用较为方便，具有一定的优势。

The Influence of Effective Thermal Conductivity of Wax Deposits on Heat Transfer Characteristics of Pipelines

The determination of effective thermal conductivity of wax deposits is an important part of calculation of the heat transfer in wax deposition. Based on the analysis of effective thermal conductivity calculation method of heterogeneous binary mixture, a model suitable for calculating effective thermal conductivity of wax deposits is determined, and the influence of different effective thermal conductivity calculation methods on heat transfer characteristics of pipelines is compared and analyzed. The results show that the effective thermal conductivity of wax deposits becomes larger with the increase of mass fraction of wax in the sediments. Under the same mass fraction of wax, effective thermal conductivity calculated by parallel model is the largest, followed by ME2 model, EMT model and series model, and the calculation results of ME2 model and EMT model are close. The hypothesis of EMT model is similar to the structure distribution of actual wax deposits, so it is recommended to use the EMT model to calculate effective thermal conductivity of wax deposits. The temperature along the pipe section calculated by EMT model and M correlation is very close, and radial temperature gradient obtained by EMT model is higher than M correlation. Generally speaking, the heat transfer calculation results of pipelines obtained by EMT model and M correlation have little difference, but correlation is more convenient and has certain advantages.