Based on the

a steady state distributed parameters model was established in the numerical simulation of refrigerant circuitry in condensers.The calculation results are in agreement with the experiments in the previous literature.The heat transfer and flow characteristics of six different two-rows condensers were studied with the present model.The research results show that the counter-flow condensers have a better performance than other arrangements condensers. When the front velocity is constant

there must be an optimum refrigerant mass velocity

leading to the best performance for the condensers.Similarly

when the refrigerant mass velocity is constant

there must be an optimum front velocity.In addition

the influence of gravity force cannot be ignored.Some practical refrigerant circuitry branching and joining principals were proposed and extensively studied

considering the pressure

heat resistance

and heat transfer coefficient distribution along the heat tubes.