전기히터식, 공기열원 및 지열원 열펌프식 농산물 열풍건조기의 초기투자비 분석

Price is a significant factor when purchasing hot air dryers for drying agricultural products, which differs depending on the capacity and the type of input energy. Most dryers use electricity, which is high quality but expensive. Air heat source heat pump as an alternative to electricity has better efficiency but has a drawback of low performance when outdoor air temperature is low. This can be resolved through the use of geothermal energy whose temperature is more advantageous than the ambient air. However, the high drilling cost is a great disadvantage. In this work, the initial investment cost of 50, 200, 500 and 1000 kg capacity hot air dryers are compared. The correlations are suggested for estimating the initial cost as a function of capacity. The initial cost of the electric dryer is lowest while the geothermal dryer, which requires installation of ground heat exchanger is highest. The difference between the electric and air source becomes less as the capacity is increased. When the initial costs are compared to the electric heater, the air source is higher by 1.13-1.60 times while the geothermal is higher by 3.88-8.14 times, respectively. When the results of this study are combined with operational cost including energy, it can serve as a good guideline for making decisions on the type of the dryer and in the development of government subsidy program for reducing electricity consumption.