Internal Flow Heat Transfer Rate for Parallel Heat Exchanger Pipes One Pass of Rice Husk to Air

The research was conducted to analyze the heat transfer rate of heat exchangers from black steel pipes with rice husk as an energy source. This can be used as a recommendation to replace solar energy in the post-harvest drying process, especially for small farmers in rural areas. Research by converting rice husk biomass into heat energy using a heat exchanger of black steel pipes arranged parallel to one air fluid flow. Heat exchanger pipes are placed inside the furnace with dimensions of 50 cm x 50 cm x 80 cm. Forced convection is applied through a fan placed in the drying chamber with a constant speed of 2 m/s. It was found that the ambient temperature increased by an average of 11.70% without adding rice husk mass during the test. The average ambient temperature (Ti) is 305.10 K and ranges from 300.60 to 307.40 K which can be increased to (To) 340.80 K with a range of 317.25 to 366.30 K. This temperature is the out the heat exchanger pipes that can be used for the drying process. The value of the heat transfer rate reached an average of 39.19 W with a range of 18.62-63.19 W. The pattern of distribution of heat transfer rates follows the trend of temperature distribution. It was found that when rice husk turns into charcoal it causes a high heat transfer rate. High heat transfer rates are needed in the drying process of a product so that the required time is shorter and optimal. In addition, rice husk biomass can be used as alternative energy because it is easy to obtain, especially in agricultural areas that grow rice.