Ejector technologies for performance increase of industrial heat pumps

Industrial energy systems need to be decarbonized substantially. High temperature heat pumps show large potential in supplying sustainable heat for energy intensive process industries. However, the technology comes with limited performance when high temperature lifts are required. In a national feasibility study, ejectors proved a viable device for partially recovering expansion work lost. For two industrial heating applications, one for steam production at supply temperatures of 130°C and one for industrial drying at 160°C, average increases in heating capacity of 10% resp. 9% and efficiency increases of 7% resp. 7.5% were achieved in simulations. Further areas of research include the development of a hermetic ejector design including corresponding design tools and simulation models and the experimental validation of ejectors operated under different heat pump conditions. Besides, also more detailed information is required on energy-intensive industrial processes and their detailed characteristics. This work is currently being conducted with a renowned Austrian heat pump manufacturer within a nationally funded research project.