Comparative study of heat exchanger performance calculation results between EchTherm software and experimental results - Brazed plate heat exchanger in evaporation

This technical report constitutes the first part of a comparative study devoted to assessing the consistency between the simulation results produced by EchTherm software and experimental measurements obtained from a test bench on a brazed plate heat exchanger (BPHE). The case considered concerns an evaporator operating with propane (R290), integrated into a heat pump cycle using water as the secondary fluid.

The objective of the document is to evaluate, on an experimental basis, EchTherm’s ability to reproduce the actual thermohydraulic behaviour of the equipment, to identify its strengths, to highlight its limitations, and to derive potential avenues for improving the modelling approach. This work forms part of a broader study, since a second document, dedicated to condenser operation, will complete this first analysis.

The reader will first find a detailed presentation of the test bench and measurement chain, followed by an analysis of the experimental uncertainties, which is essential for correctly assessing the significance of the deviations observed between calculation and experiment. The protocol covers 18 representative test points, selected to span the main operating parameters. The document also explains how the process data are entered into EchTherm, as well as the work carried out to reconstruct the heat exchanger geometry. On this latter point, the use of tomography provides genuine added value: it makes it possible to define key parameters that are absent from the supplier documentation and to correct certain identified geometrical discrepancies.

Throughout the document, the analysis is not limited to a direct numerical comparison. An initial comparison with the supplier data is carried out before moving on to the core of the report: an in-depth study of the deviations observed across all test points, using statistical indicators, comparative graphs, and a physical interpretation of the phenomena involved. The report therefore goes beyond simply establishing whether the level of agreement is satisfactory or not: it specifies the practical validity range of EchTherm and shows from which level of analysis a more detailed approach, such as CFD, may become relevant. This approach provides the reader not only with results, but also with genuine interpretative keys for understanding the mechanisms responsible for the observed deviations.