A comparison of transient heat pump cycle models using alternative flow descriptions

摘要

This article compares the effects of two different refrigerant flow modeling assumptions on the transient performance of vapor-compression heat pump cycles. This comparison is done on a dynamic system-level model of a flash tank vapor injection cycle that includes finite-volume heat exchanger models. The effect of the flow assumptions and specific slip ratio correlations on both the equilibrium operating point and the transient behavior of the cycle are demonstrated through both simulations and experiments. It is shown that equivalent simulations with different slip ratio correlations each have different equilibrium mass inventories and that some aspects of the dynamic system behavior, such as the suction superheat or pressure transients, exhibit significant differences both in simulations and in comparison to experimental data.