Advancing high-temperature heat pump technologies: achieving 120°C with R245fa refrigerant for sustainable industrial heating

The advent of the "Dual Carbon" targets has catalysed a transformative shift in the energy generation landscape, heralding a paradigm shift from traditional fossil-fuel heating to electricity-driven heating solutions. In this vein, heat pump technology offers an efficient pathway to reclaim industrial waste heat and enhance energy utilization. For now, mature heat pump technology primarily offers heating temperatures below 90°C, whereas heating temperatures required for industrial processes are mostly above 100°C. To achieve the replacement of fossil-fuel boilers with heat pumps in industrial heating, the development of high-temperature heat pump (HTHP) technology becomes imperative. Therefore, a reliable cooling strategy is the basis for HTHP. This study introduces a R245fa industrial HTHP prototype featuring an innovative ejector-based cooling circuit designed to maintain safe operating temperatures for electronic devices. The cooling circuit can move waste heat from the electronic device to the heat pump cycle via vapor injection. From dynamic mathematical modelling and simulation, the heat pump system demonstrates a Coefficient of Performance (COP) exceeding 4.0 under 60°C heat source and 120°C supply temperature. Furthermore, we have experimentally validated the condition of the output temperature being lower than 90°C, where the COP is always above 4.8. Finally, the carbon emission reduction potential of the HTHP prototype is calculated. This advancement not only challenges the existing boundaries of heat pump applications, but also aligns with the broader objective of energy conservation and carbon emission reduction. It offers a powerful solution for industries transitioning from fossil-fuel heating to more sustainable and efficient thermal processes.