Application of liquid-separation condensation to plate heat exchanger: Comparative studies

摘要

Plate heat exchanger (PHE) is popularly used as the condenser. The condensation heat transfer along the plate in a conventional plate condenser (CPC) is unavoidably worsened due to condensate accumulation. In this paper, the liquid-separation condensation is applied to plate condenser (LPC) by removing the condensate for heat transfer enhancements. The working principles and the structure of LPC are described in details. A mathematical model is established. With focus on a simple LPC, the refrigerant side performance is identified by the performance evaluation parameter (PEC), while its overall performance integrating water side is evaluated by the exergy efficiency (eta). Results show that in LPC, PEC and eta reach to their maximum values simultaneously when the path length ratio (PLRk) and corrugation amplitude ratio (CAR(k)) are at 0.4 and 0.72, respectively. With the optimized configuration of LPC, the initial refrigerant mass flow rate ((m)over dot(r,1)) and inlet vapor quality (x(r,in)(,1)) are parametrically investigated. Their increments benefit LPC performance that is mainly contributed by the second path. LPC has magnitudes of PEC always greater than one, indicating the effectiveness of liquid-separation condensation. LPC performance is superior to CPC in terms of a higher heat load (Q(r)) and an improved exergy efficiency (eta).