平均有效传热温差Mn=T-t=M,-△ 理论传热温差Mn=T-T 总温差损失△=△+△"+△m △’=f·△。∫=0.0162 △"=T-TK P+ 2 0.5~1.5°C平均有效传热温差 tm = T − t = t r −  理论传热温差 r T TK t = −  总温差损失  =  +  +  C gl T T K P P r T f f pm m K  =   = −  = +    =   = 0.5 ~ 1.5 2 0.0162 2 0 