Experimental study on boiling heat transfer of R245fa outside low-fin tube
Experimental research was conducted on the external boiling heat transfer performance of low-fin tubes using R245fa in a large-scale evaporator.Based on the experimental results at evaporating pressures of 0.88,0.78 and 0.68 MPa,the corresponding heat transfer correlations were obtained using the Wilson plot method,and the results were compared with those in the literature.The experimental results showed that the external boiling heat transfer coefficient of R245fa could reach 11 000～18 000 W/(m2·K)at a heat flux density of about 23 000～32 000 W/m2.Within the range of experimental conditions,the external heat transfer coefficient increased with the increase of evaporating pressure and heat flux density,and the enhancement ratio is about 2.800 times compared with the predicted value of the smooth tube heat transfer coefficient in the literature.In addition,the heat transfer correlation for external boiling of low-fin tubes was given under experimental condition,as well as the correction factors required for the Cooper and Gorenflo correlations to be used for low-fin tubes in this form.
NETL
NSTL
万方数据
维普
