Journal of the Korean Society for Geothermal and Hydrothermal Energy (한국지열·수열에너지학회논문집)

Korean Society for Geothermal and Hydrothermal Energy (한국지열·수열에너지학회)
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Effect of Operating Conditions of a Fan-Coil Unit with an Oval Tube Type Heat Exchanger on Non-Dimensional Performance Coefficient

타원관 열교환기를 적용한 팬코일 유닛의 운전 조건이 무차원 성능계수에 미치는 영향

  • 윤재동 (서울과기대 에너지환경대학원) ;
  • 이영훈 (서울과기대 일반대학원) ;
  • 성재용 (서울과기대 기계자동차공학과)
  • Received : 2019.01.28
  • Accepted : 2019.02.28
  • Published : 2019.03.01
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Abstract

In this study, the effect of operating conditions of fan-coil unit with an oval tube type heat exchanger on its non-dimensional performance coefficient has been investigated. Pressure drops and heat transfer rates were measured under heating condition for various water flow rates, inlet temperatures and wind speeds. As a non-dimensional performance coefficient, Colburn j-factor was evaluated. The results show that the most sensitive parameter on heat flux is the inlet temperature, which affects the heat flux 4.7 and 7.2 times more than the wind speed and water flow rate, respectively. On the other hand, the Colburn j-factor as a non-dimensionalized index decreases with the wind speed, and has an maximum when the wind speed is about 1 m/s. the Colburn j-factor increases slowly with the water flow rate and inlet temperature but at a certain range of inlet temperature, the opposite phenomenon is found.

Keywords

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Fig. 1. Experimental setup to measure the performance of a fan coil unit.

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Fig. 2. Photo of the oval tube type heat exchanger applied to the fan coil unit.

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Fig. 3. Wind speed according to the fan motor speed.

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Fig. 4. Pressure loss of water flow according to the Reynolds number.

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Fig. 5. Heat flux and Colburn j-factor according to the wind speed at the water flow rate of 6 lpm.

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Fig. 6. Heat flux and Colburn j-factor according to the water flow rate at the wind speed of 1.08 m/s.

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Fig. 7. Heat flux and Colburn j-factor according to the temperature at the wind speed of 1.08 m/s.

Table 1. Geometrical parameters of the oval tube type heat exchanger

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Table 2. Experimental conditions.

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