Techno-economic and environmental assessment of a moderately high-temperature heat pump prototype using R-450A across diverse operational conditions and heat sources

Decarbonizing the industrial sector requires the adoption of efficient electric-driven energy conversion systems, and high-temperature heat pumps may offer a viable alternative. This study presents an energy, environmental, and economic assessment of an industrial heat pump prototype using R-450A for 85 °C process heating, comparing it with a traditional natural gas-fired boiler. Twenty-seven steady-state heat pump operational conditions are examined. Simulation analysis is then performed across thirty-two scenarios using multi-variable linear regression models built on the results of experimental tests. The conditions investigated vary in heat pump control strategy, configuration (with or without an internal heat exchanger), and heat source (different generations of district heating networks, district cooling networks, or air). One-year-long simulations are carried out on an hourly basis, considering the air-source heat pump installed in six Italian cities. The results highlight that maximizing compressor frequency reduces heat pump performance, which also decreases with an increasing pressure ratio when the condensation temperature is set. While carbon dioxide emissions are always avoided compared to the traditional boiler, a trade-off is required between the heat pump's energy, environmental, and economic performance. The best-performing configuration results in approximately 5 % primary energy saving, 31 % carbon dioxide emissions avoided, and 30 % operational cost reduction.