• 제목/요약/키워드: Plate-Finned Heat Exchanger

검색결과 11건 처리시간 0.023초

오일 쿨러의 열전달 성능에 관한 실험적 연구 (Experimental Study on Heat Transfer Performance of Oil Cooler)

  • 조동현;임태우
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2328-2333
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    • 2008
  • The experimental study was carried out to evaluate the heat transfer performance on the shell side of shell-and-plate finned tube heat exchanger with three different tube numbers(9, 13 and 19). Oil flowing on the shell side was cooled by cold water flowing inside the tubes. A shell-and-tube heat exchanger of an oil cooler consisted of one shell pass and two tube passes with the inner tube diameter of 8.82 mm and the tube length of 575 mm. Mass flow rate was varied from 1.2 to $6.0\;m^3/h$ for oil and from 0.6 to $3.0\;m^3/h$ for cold water, respectively. From the experiment of shell-and-plate finned tube heat exchanger, the shell side heat transfer coefficient of heat exchanger with 9 tubes was compared with that of 13 and 19 tubes. It was found that the heat exchanger with 9 plate finned tubes showed more performance of heat transfer than that of 13 and 19 tubes.

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판형 핀을 가진 원통-다관형 열교환기의 열전달 특성에 관한 연구 (Study on Heat Transfer Characteristic of Shell-and-Tube Heat Exchanger with Plate Fin)

  • 임태우;조동현
    • 한국산학기술학회논문지
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    • 제10권1호
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    • pp.46-51
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    • 2009
  • 본 논문은 세 개의 서로 다른 관수(9, 13 그리고 19)를 가지는 원통-판형 핀 관의 원통 측에서의 열전달 성능을 실험적 방법으로 평가하였다 관외를 흐르는 오일은 관내를 흐르는 냉각수에 의해 냉각된다. 오일 쿨러의 원통-다관형 열교환기는 단일 셀 통로와 두 개의 관 통로로 구성되며, 관 내경은 8.82mm, 관 길이는 575mm이다. 오일의 질량 유량은 $1.2{\sim}6.0m^3/h$이며, 냉각수의 질량 유량은 $0.6{\sim}3.0m^3/h$이다. 실험결과 9개의 관수를 가지는 열교환기의 총합 열전달계수는 13개와 19개의 관수의 열전달계수보다 각각 약 1.8배와 2.3배 높게 나타났다.

판형 열교환기의 열전달성능 손실 없이 유동방향 길이를 축소하는 방법 (A Method to Reduce Flow Depth of a Plate Heat Exchanger without a Loss of Heat Transfer Performance)

  • 송귀은;이대영
    • 설비공학논문집
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    • 제18권2호
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    • pp.129-136
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    • 2006
  • Optimal design of an air-to-liquid finned plate heat exchanger is considered theoretically in this study. Based on existing correlations for the pressure loss and the heat transfer in channel flows, the optimal configuration of the plate heat exchanger including the optimal plate pitch and the optimal fin pitch is obtained to maximize the heat transfer within the limit of the pressure drop for a given flow depth of the plate heat exchanger. It is found that the optimal fin pitch is about one ninth of the optimal plate pitch. In the optimal configuration, the flow and thermal condition in the channels is just at the boundary between the laminar developing and laminar fully developed states. It is also found when reducing the flow depth of plate heat exchangers for compactness, the heat transfer performance can be maintained exactly the same if the geometric parameters such as the plate thickness, plate pitch, fin thickness, and fin pitch are reduced proportional to the square root of the flow depth as long as the flow keeps laminar within the heat exchangers.

밀집형 열교환기에 사용하는 평판핀 성능에 관한 수치적 연구 (Numerical investigation of plate fin performance for a compact heat exchanger)

  • 유재욱;송태호
    • 설비공학논문집
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    • 제11권3호
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    • pp.292-300
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    • 1999
  • Fin conduction not only enhances heat transfer to the ambient air but also increases tube-to-tube conduction. The latter is known to deteriorate the heat exchanger performance. Heat conduction between neighboring tubes thorough the fin is numerically investigated for accurate performance analysis of plate finned-tube heat exchangers. Governing equations for arbitrary plate fin are solved and the temperature distribution is obtained using the principle of superposition. Analysis is made using finite element method by changing the shapes of fin, the arrangements of tubes and the fin parameter mD. It is found that tube-to-tube conduction is significant when mD is small or the distance between neighboring tubes is small.

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평판핀이 부착된 증발기의 특성에 관한 연구 (A Study on the Characteristics of Plate Finned-Tubes Evaporator)

  • 손병진;민묘식;김홍배
    • 대한기계학회논문집
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    • 제15권3호
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    • pp.982-991
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    • 1991
  • 본 연구에서는 냉방기에서 널리 이용되고 있는 평판핀이 연속적으로 부착된 다관식 증발 열교환기에 대하여 (1) 냉매의 열역학적 물성치의 변화 (2) 냉매와 공기 측 열전달 계수의 변화 (3) 냉매측 관 마찰 손실등을 고려한 시뮬레이션 프로그램을 작성하고 그 결과를 실험을 통하여 보정 완성하였다. 계산결과로 부터 공조기기의 설계조건, 공조계통 해석을 위한 기초자료를 제시하였다.

Modifications and Assessment of RELAP5/MOD3.2 for HANARO Thermal-Hydraulic Safety Analyses

  • Gee Yang Han;Kwi Seok Ha
    • Nuclear Engineering and Technology
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    • 제34권5호
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    • pp.455-467
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    • 2002
  • RELAP5/MOD3.2 was modified to perform the thermal-hydraulic safety analysis for HANARO transients. Several aspects of RELAP5/MOD3.2 were modified or replaced by new features to properly simulate the unique HANARO characteristics such as the finned fuel element, the cooling mechanisms by both plate type heat exchanger and the natural circulation. Especially, the heat transfer packages were modified to be more appropriate for the safety analysis and the heat transfer models were developed for the plate type heat exchanger as well as natural circulation through the pool water. This modified version of RELAP5/MOD3.2 is renamed as RELAP5/HANARO. The thermal-hydraulic simulations of the single fuel pin test and plate type heat exchanger were peformed to assess the realistic predicting capabilities of RELAP5/HANARO and compared with experimental results and manufacturer's data in this paper. In addition, the natural circulation experiment using the scaled bundle was simulated to validate the capability of RELAP5/HANARO. The simulation results show almost similar trend with experimental data. Therefore, it is proved that RELAP5/HANARO has a confidence to use for the safety analyses of HANARO.

유냉각기의 열전달 촉진에 관한 연구 (A Study on Heat Transfer Enhancement of Oil Cooler)

  • 조동현;임태우
    • 동력기계공학회지
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    • 제15권3호
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    • pp.25-30
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    • 2011
  • A shell-and-tube oil cooler with plate fins was suggested to improve the defect of the conventional shell-and-tube oil cooler. Experiments were conducted to evaluate the heat transfer performance on the shell side of shell-and-plate finned tube oil cooler with three different tube numbers(9, 13 and 19). Oil flowing on the shell side was cooled by cold water flowing inside the tubes. A shell-and-tube heat exchanger of an oil cooler consisted of one shell pass and two tube passes with the inner tube diameter of 8.82 mm and the tube length of 575 mm. From the experiment of shell-and-tube oil cooler, it was found that the heat transfer coefficient of oil cooler with 9 tubes, as oil flow rate was increased, was approximately 140% and 250% higher than that of 13 and 19 tubes, respectively. The heat transfer coefficient at the water flow rate of $3m^3/h$, also was 120% and 140% higher than that of 2.4 and $1.8m^3/h$, respectively.

미소열교환기법에 의한 밀집형 열교환기의 성능 계산 : 핀을 통한 튜브간 전도의 영향 (Computation of Compact Heat Exchanger Performance by the Heat Exchangelet Method : Effect of Tube-to-tube Conduction along the Fin)

  • 성시경;송태호;최영철
    • 설비공학논문집
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    • 제12권5호
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    • pp.494-501
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    • 2000
  • Effectiveness of a 3-pass plate finned-tube heat exchanger is calculated using heat exchangelet method by changing the shape of fin and the arrangement of tubes. The alternative refrigerant R134a is taken in this study. Conduction between neighboring tubes along the fin is taken into account in addition to convection between the fin and the surrounding air. Governing equations are obtained by using energy balance in a small control volume containing a tube and fins. They are numerically solved following the tube. Effect of tube-to-tube conduction is investigated in single-phase and two-phase flows with various fin shapes and arrangements of tubes. Improvement of effectiveness by fin perforation is studied too. The results shows that perforating fins, increasing the number of tubes, and increasing the distance between neighboring tubes at the same fin area enhance the effectiveness.

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슬릿과 평판 핀-관 열교환기의 공기측 열전달 및 마찰특성 (Air-side Heat Transfer and Friction Characteristics of Finned Tube Beat Exchangers with Slit Fin or Plain Fin)

  • 권영철;장근선;박병권;권정태;정지환
    • 에너지공학
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    • 제16권1호
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    • pp.7-14
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    • 2007
  • 본 연구는 핀-관 열교환기의 건표면과 습표면 조건에서의 공기측 열전달 및 마찰특성을 실험을 통해 이해하고자 수행하였다. 핀-관 열교환기의 성능평가 및 해석기술을 확보하기 위하여 공기엔탈피식 칼로리 미터를 이용하였다. 핀형상은 슬릿과 평판이며, 관경은 7.0mm로 2열과 3열 핀-관 열교환기 4종에 대해 실험하여, 건표면과 습표면의 공기측 열전달 및 마찰특성을 조사하였다. 습표면에서 습도변화(RH 50%, 70%)에 따른 습도영향도 조사하였다. 건표면 조건에서 Re 수가 증가할수록 j 계수는 감소하며, 2열이 3열보다 높았다. 마찰계수는 슬릿 핀이 평판 핀보다 높았다. 습표면 조건에서 슬릿 핀이 평판 핀보다 그리고 2열이 3열보다 우수한 열전달효과를 나타내었다. j 계수와 마찰계수는 습도변화, 열수, 핀 형상에 따라 달라짐을 확인하였다.

설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제29권6호
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    • pp.327-340
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    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.