Analysis And Experimental Study Outside A Horizontal C-S Tube For Condensation Of R22

The horizontal C-S tube and R22 refrigerating medium are used the targets of the research. Based on the theoretical analysis and experimental research, the paper discusses performance of R22 condensation on horizontal C-S tube. Combined with gravity, surface tension, vapor velocity and cooling water velocity to the impact of R22 condensation on horizontal C-S tube, the paper deduces the relational expression on horizontal C-S tube which is in the tube-in-tube condenser. The process of the paper is followed.First, the paper starts with the Nusselt model from continuity equation, energy equation and momentum equation, and individually establishes gravity model and surface tension model. At the same time, the paper divides the C-S tube into two regions: inundated area and uninundated area, and then the uninundated area is divided into fin part (including top and fin-flank) and parent tube which is between fins. The surface tension model is adapted on fin-top and fin-flank part, and the gravity model is adapted on parent tube. However, the high vapor velocity in the tube-in-tube condenser has shearing action for condensed fluid to accelerate obscission of liquid, which enhances effect of condensation. So the vapor velocity must be considered, and the correction factorεis used. According to experimental discovery, when cooling water is enlarged, the coefficient of heat transfer is also increased, which declares mutually effect of liquid influence with heat transfer. So the correction factorξis used to correct the effect of cooling water velocity. Combined with above all factors, the relational expression of heat transfer for condensationαois given.The theory and experiment state that the geometric profile fully may make use of surface tension to enhance the condensation of R22 performance on horizontal C-S tube. Of course, cooling water and vapor velocity are also important factors. Compared with experimental result, the relational expression is approximate concordance, which proves the analysis true.