라멜라 열교환기 내에 딤플 직경에 따른 열전달 특성 변화 영향

초록

The steel industry is well-known for issues with severe pollution due to the massive amounts of wastewater and high-temperature exhaust gases generated during the production of steel. However, recovering this waste heat for subsequent reuse in other processes can reduce fuel consumption and lower greenhouse gas emissions. To that end, lamellar heat exchangers have been developed to recover waste heat in steel production. In this study, variations in the heat transfer characteristics of a heat exchanger with dimples of different diameters on the surface of the heat transfer elements were evaluated. The results showed that regardless of the diameter of the dimples, the efficiency of the unit decreased with an increasing mass flow rate of air and the pressure drop between the air inlet and outlet increased, whereas that between the gas inlet and outlet decreased. Notably, the efficiency of the heat exchanger improved as the diameter of the dimples was increased, and the pressure drop between the air and gas inlets and outlets both increased. This confirms that the flow rate of air and the diameter of the dimples within the channels exhibited a significant impact on efficiency in the design of a lamellar heat exchanger, and they also affected the drop in pressure between the inlet and outlet.

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