Performance of ejection refrigeration system operating with R-1234ze(E) driven by ultra-low grade heat source

New experimental investigations of the ejection refrigeration system focusing on the ejector efficiency are presented and discussed. The refrigerant R-1234ze(E) was used as a working fluid. The system is driven with low grade heat source of temperature below 60 degrees C. The coefficient K, which can be considered as the overall loss coefficient is presented and discussed. On the basis of experimental results K values for various operation conditions were determined. The experiments show that for all of the cases the coefficient K exceeds 0.70. Also overall efficiency of the ejector was determined. The ejector in the described system achieves the efficiency up to 0.27 for the analysed operation conditions. Exemplary pressure and temperature distributions along the ejector are presented and discussed. (C) 2018 Elsevier Ltd and IIR. All rights reserved.