Validation of advanced fin-and-tube heat exchanger models with cross-fin conduction functionality

Abstract

Abstract A variety of fin-and-tube heat exchanger models have been developed to predict heat exchangers’ performance metrics (e.g. capacity). Prediction of performance metrics of heat exchangers with these features are significantly less accurate without consideration of cross-fin conduction. This work presents a validation of two different heat exchanger models that considers the cross-fin conduction against two-phase refrigerant data. The first heat exchanger model i.e. cross-fin model is a detailed segment-by-segment model while the second model i.e. fin discretized model is a reduced order segment-by-segment model. An experimental facility was established to obtain two-phase experimental data that can test the evaporator or condenser coil up to 17.6 kW (5 tons) capacity. An 8-circuit fin-and-tube heat exchanger was custom manufactured for validation purposes, and was tested in the facility. The model results are compared against the experimental data obtained for the following cases: 7 active circuits, 4 active circuits, and 3 active circuits that have refrigerant flow in their tubes. The cross-fin model with the consideration of cross-fin conduction and fin discretized model predicted the experimental capacity within 0–8% for all test cases. However, the maximum difference in capacity predicted by cross-fin model without cross-fin conduction consideration from the experimental capacity was more than 30% for 3 active circuits.