Comparative study of heat transfer enhancement on liquid-vapor separation plate condenser

Abstract

Basic structures of liquid-vapor separation cooling plates (LSCPs) and a liquid-vapor separation plate condenser (LVSPC) are innovatively designed. Strengthening heat transfer principle of the LSCPs is demonstrated by theoretical analysis. The average condensation heat transfer coefficients (ACHTCs) of the LSCPs are calculated and compared with conventional cooling plate (CCP). Results show that for a laminar flow, the ACHTCs of 2-parts liquid-vapor separation cooling plate and 3-parts liquid-vapor separation cooling plate are respectively 19% and 32% higher than the ACHTCs of the CCP in the same conditions. The ACHTC ratio of N-parts liquid-vapor separation cooling plates (NLSCP) to CCP is N4$\sqrt[4]{N}$in the same conditions. For a turbulent flow, results show the smaller the height of condensation area, the greater the ACHTCs of cooling plate. In the LVSPC study, operation conditions include the refrigerant R134a mass flux ranging from 22 to 32 kg/(m2.s) and inlet vapor quality from 0.5 to 1 for the saturated temperature of 40∘C. Calculation results showed that the ACHTCs of the LVSPC are 6–24% higher than the ACHTCs of the given common plate condenser (CPC), and similar to the CPC, the ACHTCs of the LVSPC increases with the increase of mass flux and vapor quality.

Keywords

• liquid-vapor separation
• plate heat exchanger
• condensation heat transfer
• numerical simulation