Simulation model for complex refrigeration systems based on two-phase fluid network – Part II: Model application

A simulation model of complex refrigeration system based on two-phase fluid network is developed in part I of the paper [Shao, S.Q., Shi, W.X., Li, X.T., Yan, Q.S., 2008. Simulation model for complex heat pump systems based on two-phase fluid network – part I: model development. International Journal of Refrigeration 31 (3), 490–499.]. One same fluid network is used in the model to describe the refrigeration system in different operating modes with the method of the factual and fictitious branches. When there are many heat exchangers with concurrent cooling and heating, the traditional models are not able to define the flowing directions. The developed model, however, whether the initial flowing direction of the connecting branches is right or not, is able to predict the flow and heat transfer. Three typical complex refrigeration systems such as the multi-unit inverter air conditioner, heat pump with domestic hot water and multi-unit heat pump dehumidifier are simulated with the developed model as demonstrations on how to use it. The model can evaluate the influences of one or more parameters on the system performance, which can be used for the optimization of the system by all-condition performance analysis. It is shown that the two-phase fluid network model is effective and convenient for the simulation of different complex refrigeration system, especially for performance analysis, system evaluation, and optimization based on the performance prediction.