Numerical simulation of capillary-tube expansion devices behaviour with pure and mixed refrigerants considering metastable region. Part II: experimental validation and parametric studies

A detailed one-dimensional steady and transient numerical simulation of the thermal and fluid-dynamic behaviour of capillary-tube expansion devices working with pure and mixed refrigerants has been developed and presented in part I of this article. The accuracy of the detailed simulation model is demonstrated in this paper by comparison with experimental data from the technical literature. Results presented include both metastable flow modelling and non-metastable flow modelling, homogeneous and separated flow model for metastable flow and the used of different empirical correlation needed in the numerical model. Comparisons of model prediction between various approaches are discussed. Numerical results and parametric studies for concentric capillary tube-suction line heat exchangers have also been presented.