Solar Energy (태양에너지)

The Korean Solar Energy Society (한국태양에너지학회)
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The Experimental Study on the Heat Transfer Characteristics

가스보일러 코일형 열교환기의 열전달 특성에 관한 실험적 연구

  • Hong, S.H. (Inha University, Graduate School) ;
  • Kim, Y.K. (Inha University, Graduate School) ;
  • Kim, I.G. (Inha University, Graduate School) ;
  • Kim, D.C. (Inha University, Graduate School) ;
  • Lee, C.E. (Dept. of Mechanical Engineering, Inha University) ;
  • Yim, C.S. (Dept. of Mechanical Engineering, Inha University)
  • Published : 1997.12.30
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Abstract

The performance of gas-fired boilers were experimentally investigated. The heat exchanger used for the experiments consisted of circular tube with longitudinal fins for the gas side and a spiral coil for the water side. The burner was located at the top of the heat exchanger, and the burned gas flowed down to the exit. The experiments carried out for different water flow rates, the heat capacities of the boiler and the number of baffle. The thermal efficiency of the upward flow was higher than that of the downward flow of the water in the heat exchanger. As the boiler capacity increased, the thermal efficiency decreased. As the number of the baffles increase, the thermal efficiency increased and the increasing rate of the efficiency decreased. The gas-side overall heat transfer coefficient was independent of the flow rate of the water. The effect of the number of the baffles on the heat transfer coefficient was greater than that of the boiler capacity.

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