竖壁膜状凝结传递特性研究

The Research of the Exergy Transfer Characteristic in the Vertical Surface Condensation

传递的分析方法比能量平衡的分析方法更加关注能量品质的蜕变规律。借鉴努塞尔蒸汽层流膜状凝结的分析解中竖直平壁凝结液膜的厚度与传热系数表达式,引入传递理论的研究方法,得到竖直平壁凝结换热局部传递系数表达式,通过对不同壁面过冷度情况下对壁面液膜厚度、传热系数及传递系数计算,结果显示过冷度越大,壁面厚度增大,传热系数减小,但传递系数变大。通过对计算结果的分析可知,壁面过冷度增加可增加传量,达到强化换热的目的。

The analysis method of exergy transfer pay more attention to the quality of the energy in process of energy transferring than the mcthod of energy equilibrium. This article borrowed the expression of the thickness of liquid film and the heat transfer coefficient from the analytical solution for laminar film condensation of vapor which studied by Nusseh. Through lead into the research method of the theory of the exergy transfer, the local resistance coefficient of the expression of exergy transfer during thevertical surface condensation can concluded. Calculate the thinkness of liquid film, coefficient of the heat transfer and exergy transfer at the different condenser depression on the surface, ~dill reach a conclusion of that if the condenser depression is largen the coefficient of the heat transfer will reduce, and the coefficient of the exergy transfer will raise. So increase the condenser depression will raise the amount of the exergy transfer, achieve the goal of enhance the heat transfer.