Research On Condensation Heat Transfer And Enhancement Of Different Refeigerants On Horizontal Stainless Steel Smooth And Enhanced Tubes

R22 is seriously harmful to the ozone layer. For the safety of human environment it is necessary to forbid the usage of R22 in the future. Currently, there are three kinds of well alternative refrigerants which are R134a, R410A and R407C for R22. But the multi-component refrigerants with low heat transfer efficiency. Therefore, it require us must adopt the heat transfer enhancement technology so as to meet the effect of energy-saving, material-saving, weight-decreasing and compaction and the requirement of economic benefits. The stainless steel micro-fin finned tube which was used in this study has a unique structure, it can enhance the heat transfer performance of condsation effectively so as to improve the heat transfer performance.The condensation heat transfer performance of R22, R134a, R407C and R410A on stainless steel tubes and micro-fin tube have been studied as the saturated condensation temperature are 35℃and 40℃. By data measuring, inlet and outlet temperature in each experimental tube and saturated vapor condensation temperature outside each tube were obtained so that total heat transfer coefficient of each experimental tube was calculated. Moreover, useing the empirical formula of smooth tube heat transfer coefficient to calculate the convective heat transfer coefficient, and basing on the calculated the tube wall resistance, the condensation heat transfer coefficients (HTCs) on experimental tubes were gained using the heat transfer equation. Based on Error-transmission Format the relative error of K has been analyzed, the results show that relative error of K is 2.05%.The results show that stainless steel micro-finned tube can effectively improve the HTCs of R22, R134a, R410A and R407C, because micro-fin tube can effectively cut pipe the condensate film, reducing transfer resistance. Under the same?T, the HTCs of R22, R134a, R407C and R410A on experimental stainless steel MFT1 and MFT2 are 2.23, 2.21, 3.22, 1.97 and 2.67, 2.55, 3.55, 2.22 times than that of smooth rube, the heat transfer performance of MFT2 is higher than MFT1; The steam temperature have a large effect to the heat transfer performance, the condensation heat transfer coefficient of the refrigerant whose saturation temperature is 35℃is higher than 39℃; Tube bundle has a significantly affect to condensation, for the refrigerant R22, R134a, R410A, the condensation heat transfer coefficient is a decreasing trend from top to bottom, because the influence of inundation effect, for the non-azeotropic mixture R407C, the influence of inundation effect is not significant, the condensation heat transfer coefficient from the top to bottom does not necessarily rule.