Evaluation of Heat Transfer Correlations for Flow Condensation in Plate Heat Exchangers and their Impact on the Design of Organic Rankine Cycle Systems

orc2019 Tracking Number 147

A well-verified heat transfer correlation to predict the thermal performance of flow condensation is essential for optimal condenser design in organic Rankine cycle systems. This paper aims at evaluating the prediction accuracy of existing correlations for the flow condensation in plate heat exchangers, and studying the impact of using different correlations for the design and performance estimation of organic Rankine cycle units. In order to achieve these goals, an experimental test campaign was conducted with the working conditions that commonly prevail in condensers of organic Rankine cycle units, and the test data were subsequently utilized for comparison with the predicted values calculated using existing correlations. Moreover, a simulation framework was applied for a case study of waste heat recovery. The results indicate that the correlations from Yan et al. (1999) show best predictive performance to the test data, resulting in a mean absolute percentage deviations below 20 %. With respect to the case study, the required heat transfer area for the plate condenser ranged from 75.8 m2 to 132 m2, and the estimated power output of the unit, for a given condenser design, varied in the range -7.2 % to +8 % compared to the target value. The results hence indicate the need for more accurate prediction methods and generally applicable heat transfer correlations.