• Title/Summary/Keyword: Double-tube heat exchanger

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Effectiveness Measurement of a Double-Tube Heat Exchanger for a Hydrogen Liquefaction System (수소액화 시스템용 이중관 열교환기의 유용도 측정)

  • Choi, H.J.;Baik, J.H.;Kang, B.H.;Choi, Y.D.
    • Transactions of the Korean hydrogen and new energy society
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    • v.10 no.1
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    • pp.19-26
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    • 1999
  • The effectiveness of a double-tube heat exchanger has been investigated experimentally. This problem is of particular interest in the design of the heat exchanger in a hydrogen liquefaction system. Temperature, pressure, and mass flow rate for hydrogen were measured both in inner tube and in annulus of a double-tube heat exchanger. The effectiveness could be evaluated from the measured temperature and mass flow rate. It is found that the effectiveness increases with an increase in the heat transfer area of a double-tube heat exchanger and with a decrease of the heat capacity ratio. But the increase rate of the effectiveness decreased with a decrease of the heat capacity ratio. Therefore, it is presented that a criterion for selecting the heat exchanger length and heat capacity ratio to obtain the effectiveness required in a hydrogen liquefaction system.

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Design and performance analysis of water-to-air heat pump system using double-tube heat exchanger (이중관 열교환기를 사용한 물 대 공기 열펌프 시스템의 설계와 성능해석)

  • Han, D.Y.;Park, K.J.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.4
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    • pp.462-471
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    • 1997
  • The water-to-air heat pump system requires relatively lower energy consumption and less installation space. The heat exchangers used for this system are the finned-tube type for the indoor unit and the double-tube type for the outdoor unit. Mathematical models for this system are developed and programmed in computer. Experimental data from various conditions are obtained and compared with calculated values from the computer simulation program. Differences of cooling capacity and COP are 1.25% and 0.47%, and those of heating capacity and COP are 0.51% and 0.13%, respectively. Simulation results are in good agreement with test results. Therefore, the developed program is effectively used for the design and the performance prediction of water-to-air heat pump system.

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Flow Characteristic with Distance of Inlet Port and Rotating Length of Fluid in the Double Heat Exchanger (이중관 열교환기의 유체 유입위치와 회전길이에 따른 유동특성)

  • Lee, Seung-Ha;Cha, Dong-An;Kwon, Oh-Kyung
    • Journal of Power System Engineering
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    • v.17 no.4
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    • pp.51-57
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    • 2013
  • The length and position of the inlet port on the double tube heat exchanger is analyzed by CFX ver.11 for studying the characteristic of its flow distribution. When the boundary conditions of the inlet temperature and mass flow rate were each $20^{\circ}C$ and 10 ~ 50 kg/min, 3 models that are based on the distance between the inlet port and the center of the heat exchanger(0, 5.025, 10.05 mm) were analyzed to find the uniformity of the flow rate. Based on the flow rate, 4 lengths (23.723, 33.890, 44.057, 57.274 mm) were used to study the flow distribution according to Reynolds Number. The results show that, when the distance from the inlet to the position of the center of the heat exchanger is 10.05 mm and the length is 57.274 mm, the flow distribution is the most unified.

An Experimental Study of the Performance Characteristics on Multiple-tube Heat Exchanger in the Vapor Compression Refrigeration System (증기압축식 냉동장치에서 다증관 열교환기의 성능특성에 관한 실험적 연구)

  • Kim, Jae-Dol
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.1
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    • pp.37-43
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    • 2009
  • This paper is performed to develop a tripple-tube exchanger which can improve the system efficiency. Three different tube diameters are compacted by one body(tripple-tube) to recover waste heat from heat exchanging among the fluids. With this, the tripple-tube shows higher cooling capacity than the double-tube after comparing between those two systems. The results of this paper are basic data to design the optimum tripple-tube heat exchanger.