Experimental and numerical investigations of a new high temperature heat pump for industrial heat recovery using water as refrigerant

•New high temperature heat pump using water as refrigerant has been designed and built.•Experimental investigations were carried out at high temperature levels.•Transient heat pump model has been developed using Modelica.•Start-up phase has been experimentally and numerically simulated and compared.•The results show the energy savings and the environmental benefits of the prototype.

A new high temperature heat pump using water as refrigerant has been designed and built for testing on a laboratory test bench that reproduces the operating conditions of real-case industrial applications. Experimental investigations of this heat pump were carried out in the condensing temperature range of 130–140 °C. A new dynamic model has also been developed using Modelica to take into account the presence of non-condensable gases and the purging mechanism. In addition, a new combined finite-volume and moving boundary method (FV-MB) approach is applied for the plate heat-exchanger models and a moving boundary (MB) approach between phases is implemented for the models of the purging and the flash evaporation systems. The start-up phase of this high-temperature heat recovery and heat enhancement of the heat pump are simulated experimentally and numerically. A comparison between both results is presented and analyzed. Global energy savings and the environmental benefits have been illustrated.