采用效率一传热单元数法,针对顺流和逆流两种形式的污水套管输送换热(TDHT)系统,分析了换热效率,给出了效率计算公式和特点,指出顺流换热效率大于逆流,推荐TDHT系统采用顺流形式。提出了距离负荷比的概念,从技术和经济可行性方面给出了TDHT系统最小的距离负荷比。
Using the efficiency-number of heat transfer units method (ε-NTU method), analyses the heat-transfer efficiencies of the parallel-flow and reverse-flow forms of thimble delivery heat-transfer (TDHT) and presents the calculation formulas and related characteristics. The results indicate that the parallel-flow is higher than reverse-flow in heat-transfer efficiency and is recommended to be used for a TDHT system. Presents the definition of distance-load ratio (DLR) and obtains the minimum DLR by the analysis of technical and economic feasibility.