Abstract
Pasteurisation is an energy-intensive process inside dairies, requiring high temperatures, often achieved using oil, gas or electric steam boilers. Using high temperature heat pumps (HTHP) can instead improve energy efficiency in pasteurization, sterilization, and CIP (cleaning in place). In the current setup of a Norwegian dairy, multiple CO2-heat-pump-chillers are covering the cooling load and simultaneously producing hot water at 65 °C. The hot water is stored and used for process heating, CIP and as feedwater for the steam production by an electric steam boiler. District heating is used for space heating. If higher temperatures are required, steam is generated, and heat exchanged to produce hot water up to 96 °C. This steam generation requires 37-41 % of the primary energy demand of the plant. This study investigates the potential on how HTHPs based on natural refrigerants can be implemented to increase the energy efficiency by replacing the electrical boiler.