Combination of Dehumidifier, Heat Pump and Air Heater: Influence of Temperature, Specific Humidity, And Mass Flow Rate of Air on Specific Energy Consumption

Abstract

Drying is the process of transferring heat and mass to remove water by heat application, from solid or liquid food, to decrease water content. The temperature and drying conditions imposed on a product have an essential influence on it. Drying in high temperatures can cause damage the sensitive materials. To overcome this problem, in this paper, to show the effect of temperature, specific humidity and mass flow rate, on the specific energy consumption on the use of air heaters, and the combination refrigeration system to produce hot and dry air. In this study, we use an experimental method by using temperature variations of 60°C, 90°C, 120°C, and 150°C. Air mass flow rates using 100 Lpm, 150 Lpm, 200 Lpm, and 250 Lpm variation. The air from the environment is sucked up by the blower and then enters the evaporator. In the evaporator, the air will condensate so the air will get the low relative humidity. The heat in the condenser is used as preheating the dry air before entering the heater. To produce hot and dry air with the minimum humidity ratio (3.9 g / kg _{dry air}) for the same target temperature is recommended to use a 100Lpm airflow rate by adjusting the evaporator pressure to 2.6 bar. Then, to obtain the minimum SECR (0.928), the recommended target temperature is 120°C, by adjusting the airflow rate to 250Lpm and the pressure at the evaporator 1.6 bar.