• 대한기계학회논문집B
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• 제34권5호
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• pp.515-522
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• 2010

본 연구의 목적은 무착상 조건에서 나선형 원형핀-튜브 열교환기의 형상변수에 따른 열전달특성을 고찰하고 평판 사각핀-튜브 열교환기와 열전달성능을 비교하는 것이다. 나선형 원형핀-튜브 열교환기는 Lfoot 길이 2.7 mm 에서 열전달계수가 최대로 나타났으며, 공기측 열전달계수는 튜브열수가 2 열에서 5 열로 증가하면서 평균 10% 감소하였고 핀피치가 5 mm 에서 10 mm 로 증가하면서 평균 17.5% 증가하였다. 모든 풍량조건에서 나선형 원형핀-튜브 열교환기의 튜브피치 30 mm 가 35 mm 보다 열전달량이 평균 5.1% 높게 나타났고 튜브두께 0.5 mm 가 0.7 mm 보다 열전달량이 평균 4.1% 높게 나타났다. 나선형 원형핀-튜브 열교환기의 열전달계수가 평판 사각핀-튜브 열교환기에 비하여 평균 24.3% 정도 높게 나타났다.

• 설비공학논문집
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• 제17권6호
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• pp.529-535
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• 2005

This study experimentally examines the air-side performance of spiral finned tube heat exchangers. The effects of fin spacing, fin height, and tube alignment were investigated. Reduction of fin spacing decreased the Colburn j factor. However, the effect of fin height on the Colburn j factor was negligible. An increase of tube row decreased the Nusselt number for both staggered and in-line tube alignments. However, the decrease of the Nusselt number for the in-line tube alignment was much more significant than that of the staggered tube alignment. The average Nusselt number of the staggered tube alignment was larger than that of the in-line tube alignment by $10\%$ when the Reynolds number ranged from 300 to 1700. An empirical correlation of the Nusselt number was developed by using geometric parameters of heat exchanger and correction factors. The correction factor considered the effects of tube alignment and number of tube rows on the heat transfer. The proposed correlation yielded a mean deviation of $4\%$ from the present data.