A Universal Simulation Model of Air-Cooled Condenser Consisting of Plate-Fin-Tube

Abstract

Air-cooled condenser used for refrigeration and heat pump applications generally consists of plate-fin-tubes. A universal simulation model has been developed for simulation of plate-fin-tube condenser with distributed-parameter method. The model discretizes coil into circuit to circuit, tube to tube and then node to node along the refrigerant path and carries out repetitive marches from the refrigerant inlet to its outlet while simultaneously updating the values of the air stream properties for obtaining quick convergence. Unlike previous models, this model is capable of analyzing complicated circuiting arrangements and can take into count the variation in heat transfer coefficient and pressure drop coefficient along the tube. Especially, the coefficient of heat transfer and pressure drop of two-phase refrigerant strongly influences each other, so the pressure balance among parallel refrigerant circuits is carried out by adjusting the mass flow rate of refrigerant in each circuit. The distinguishing feature of this model is that it performs a node-to-node discretized analysis of the condenser along each circuit, making fewer assumption about the nature of heat transfer and pressure drop than traditional models. The model has been validated against experimental data on such coils available in the literature. It is not only helpful for optimal design of air-cooled condenser with any kind of complex circuiting arrangement, but also can act as a main part of the simulation model of refrigeration and heat pump systems.