平均温度差法和传热单元数法在化工换热计算中的盲区

Fade Zone on Heat Calculation Method between Mean Temperature Difference and Number of Transfer Units in Chemical Engineering

换热是《化工原理》中重要的单元操作之一,热量优化设计是现代化工设计的重要组成部分。文章运用平均温度差Δtm法和传质单元数NTU法对同一换热单元进行核算。结果表明,两种计算方法在同一计算案例中出现结论相反的"盲区"。因此,换热设计中应注意核算方法的选择。

Heat exchange is one of the most important unit operations in Principles of Chemical Engineering. Moreover, the optimization design of energy is important component part of modern chemical engineering. The same heat transfer unit was calculated using the methods of mean temperature difference and number of transfer units, respectively. The result showed that the ＂fade zone＂ of opposite conclusion was obtained in the same calculation case with these two methods. Therefore, the selection of calculation methods should be paid much attention in the design of heat exchangers.