Study of a very high temperature heat pump (reverse Brayton cycle) for industrial decarbonization
Industrial decarbonization requires high-temperature heat (above 400 °C), which is currently supplied mainly by the combustion of fuels such as oil, coal or natural gas. Although electrification offers a promising pathway toward decarbonization, its overall efficiency is often limited. As a result, industries are investigating alternative solutions tailored to their specific processes. This paper presents work carried out on a very high-temperature heat pump concept capable of delivering temperatures up to 400 °C. A numerical study was performed on several case studies involving different strategies for recovering waste heat available at various temperature levels (20 to 150 °C). The study examines how the heat-pump architecture and the choice of working fluid influence performance across these scenarios. A prototype with a capacity of several tens of kilowatts, designed to reach such high output temperatures, is currently under construction. It has been developed to allow testing with different working fluids under the conditions corresponding to the studied case scenarios, enabling experimental validation of the challenges identified through numerical simulations. CFD simulations have also been carried out on this prototype, providing performance predictions for the complete heat-pump system as it will operate on the test bench.