一个基于多因素的冷却水管等效换热系数模型

基于热对流、传输微分方程及有限单元法,研究了冷却水流速、管壁粗糙度及导热系数对混凝土与冷却水之间的等效换热系数的影响。在分析各单因素影响的基础上,提出了包含冷却水流速、管壁粗糙度及混凝土导热系数等因素的冷却水管等效换热系数模型,可较好地预测多影响因素条件下混凝土与冷却水间的换热规律。模型表明,等效换热系数与冷却水流速、管壁粗糙度及导热系数均呈幂函数递增关系,其大小取决于多因素耦合效应。相较而言,粗糙度对等效换热系数影响仅在其取值较小时最显著;混凝土导热系数变化的影响较小;冷却水流速的影响介于二者之间。

A multi-factor-based model for equivalent heat transfer coefficient of cooling pipe

Based on the heat convection & transfer differential equation and finite element method, the influence of the velocity of cooling water, the roughness of pipe wall and the thermal conductivity on the equivalent heat transfer coefficient between concrete and cooling water are studied in the paper. On the basis of the respective analysis of all the concerned factors, an equivalent heat transfer model containing the velocity, the roughness and the thermal conductivity is proposed, which can predict the heat transfer law between concrete and cooling water under complicated conditions well. The model shows that the equivalent heat transfer coefficient shows a power exponent relationship with the mentioned factors, of which the magnitude depends on the coupling effect of these factors. Relatively, the influence of the roughness on the equivalent heat transfer coefficient is most significant especially when it is small, while the influence of change of the concrete thermal conductivity is least and the influence of the water velocity is between the two other factors.