Performance of high temperature heat pump for simultaneous and efficient production of ice water and process heat

Abstract

Industrial processes like milk production often require simultaneous cooling and heating at temperature of 1 °C to 10 °C and 90 °C to 120 °C, respectively. High temperature heat pumps (HTHP) with natural working fluids are a cost-, energy efficient and sustainable solution. In this work a 20 kWth lab scale cascade heat pump is analysed to predict the performance of a 300 kWth pilot plant. The test campaign covers an evaporation temperature range of -1 °C to +1 °C and a condenser temperature range of 113 °C to 118 °C enabling ice-water chilling from 10 °C to 4 °C and a hot-water heating from 85 °C to 116 °C A Combined heating and cooling COPcombined of 2.6 to 2.8 was achieved for a temperature lift of 110 K to 80 K, respectively. This performance gives a primary energy saving potential of 57% and a potential CO2-emission reduction of 94%. It can be concluded that HTHP can produce simultaneously chilled/ice-water and hot-process water efficiently for processes like drying, sterilization, pasteurization.