CO2 heat pump, CO2 transcritical cycle, Energy-saving, Dairy process
In dairy processes, there are significant simultaneous heating and cooling demands. A novel type of transcritical CO2 heat pump system is proposed, and its features and benefits are introduced. Bassed on the technical characteristics, primary energy-savings, and operating cost aspects, the CO2 heat pump system is simulated and compared to current heating and cooling systems used in dairy plants. The results show that the highest primary energy-saving rate of the CO2 heat pump is 51.5%. For fluid milk and cheese manufacturing processes, the primary energy-saving is 36.2% and 45.1%, respectively. In addition, the operating cost savings of fluid milk and cheese production are evaluated based on the cost structures in the states of Wisconsin, California and New York.