Investigation of internal heat transfer in ejection refrigeration systems

•The paper covers the analysis of the application of internal heat transfer for the case of isobutane ejection cycle.•The own original experimental investigations of the efficiency improvement of the ejection cycle are presented.•The results proved that the application of the internal heat exchanger caused improvement of the COP up to 20%.

The paper deals with theoretical and experimental investigations of the efficiency enhancement due to internal heat transfer in ejection refrigeration system. The results of theoretical analysis of the coefficient of performance (COP) improvement were presented. Isobutane was used as a working fluid. The testing stand and the experimental results of the investigation of isobutane ejection system were present. COP of the ejection system operating with and without internal heat exchanger for various levels of the motive vapour superheating were compared. The efficiency of the tested internal heat exchanger was varied between 80% up to 100%. The results showed that the application of the internal heat exchanger leads to the improvement of COP up to 20%.