Abstract
There are numerous examples of electric heaters used in drying processes in factories. These heaters' capacities are small but energy consumption of them is large because of continuous operation, hence the development of highly efficient heat pump is expected. In our previous study, it was confirmed that a C0_2 heat pump can heat air up to 80℃ with heating capacity of 6 kW and COP of 4 under the condition that air inlet temperature is 25℃ and water mlet temperature is 30℃. In this study, efficiency improvement using with intermediate heat exchanger (IHX) and stability operation investigation in low heat source temperature were studied. It was found that IHX have limited effectiveness against COP improvement and that the heat pump can operate well in water inlet temperature of 5℃.
