Thermodynamic analysis of a novel high-temperature heat pump cycle with inter cooled compression and reheated expansion based on the reversed Brayton cycle

Abstract

High temperature heat pumps offer a promising approach to deliver CO2-neutral process heat by upgrading waste heat with electricity from renewable resources. In this work, a heat pump cycle including inter cooled compression and reheated expansion is presented and compared to the simple Brayton cycle. Numerical simulations are used to investigate the provision of process heat at 250°C and process cooling at -30°C. An exergy analysis and parameter study is carried out. The results show an improved performance of the complex cycle as a result of more efficient temperature profiles improving the exergy utilisation. While previous studies often consider idealised process variants or are focused on individual purposes, the present work contributes to the analysis and evaluation of complex cycles with multi-stage process control while simultaneously supplying heat and cold. A deeper understanding of the thermodynamic interactions provides a reliable basis for the energy-related design of systems with multiple temperature levels.