Energy-saving performance and economics of CO2 and NH3 heat pumps with simultaneous cooling and heating applications in food processing: Case studies

The annual saving rates of primary energy and operating cost of NH3 and CO2 heat pumps for seven food processes in four characteristic locations with different energy prices in the U.S. are analyzed. The modeled food processes include beer brewing, food pasteurization, fluid milk processing, cheese processing, vegetable and fruit canning, juice canning, and poultry slaughtering. The investigation focuses on the effects of the characteristics of the thermal demands, the location of the proposed systems, and the energy price structure on the savings of primary energy and the operating cost. The results indicate that the characteristics of the thermal demands are the most crucial factor. The energy price structure significantly impacts the operating cost-saving rate. The analysis shows that the annual savings of primary energy can achieve 32% in food pasteurization, 44% in beer brewing, and 35% in fluid milk processing.