• Title/Summary/Keyword: Air side pressure drop

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Investigation of Performance Characteristics in a Welded Plate Heat Exchanger according to Mass flow rate and Temperature (용접식 판형열교환기에서 작동유체의 유량과 온도변화에 따른 성능특성 고찰)

  • Ham, Jeonggyun;Kim, Min-Jun;An, Sungkook;Cho, Honghyun
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.14 no.4
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    • pp.20-26
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    • 2018
  • In this study, the performance characteristics of a welded plate heat exchanger was investigated experimentally. Performance tests were carried out according to the flow rate and inlet temperature of working fluid. As a result, the heat transfer capacity increased by 335.5 kW with an increasing the flow rate and temperature difference between hot and cold side. However, the overall heat transfer coefficient was increased with the increase of flow rate, and it was not effected significantly from inlet temperature difference between hot and cold working fluid. The pressure drop was increased by 55.78 kPa with an increasing the frow rate when the flow rate ratio between hot and cold side 1:1. However, the tendency of pressure drop was difference when flow rate ratio wasn't 1:1. In case that the flow rate ratio between hot and cold side was not 1:1, the pressure drop at the low flow rate side was higher than that when the flow rate ratio was 1:1, while pressure drop of the other side was decreased compared to that when the flow rate ratio was 1:1.

The Heat Transfer and Pressure Drop Characteristics on Microchannel PCHE with various Configurations (채널 형상에 따른 마이크로채널 PCHE의 열전달 및 압력강하 특성)

  • Kim, Yoon-Ho;Moon, Jung-Eun;Lee, Kyu-Jung
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.215-220
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    • 2008
  • A microchannel PCHE is manufactured by the two technologies of micro photo-etching and diffusion bonding. In this paper, heat transfer and pressure drop characteristics by applying various configuration for the flow channel in the microchannel PCHE is experimentally investigated. The flow channel configurations are designed three types such as straight, wavy and offset strip channels. The performance experiment of each configuration is performed for Reynolds numbers in ranges of $100{\sim}700$ under various flow conditions for the hot side and the Reynolds number of cold side is fixed at 350. The inlet temperatures of the hot side and cold side are conducted as $40^{\circ}C$ and $20^{\circ}C$, respectively. The heat transfer performance of wavy channel, which was similar to that of offset strip channel, was much higher than that of straight channel. The effectiveness of wavy channel and offset strip channel was evaluated as about $0.5{\sim}0.9$. The pressure drop of wavy channel was highest among configurations and that of offset strip channel was lower than that of straight channel because the round curved surface of each strip edge was reduced the pressure loss.

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Prediction and Experiment of Pressure Drop of R22, R407C and R410A on Design Conditions of Condenser (응축기의 설계조건에서 R22, R407C, R410A의 압력강하 예측 및 실험)

  • 김창덕;박일환;이진호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.1
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    • pp.42-53
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    • 2004
  • An experimental study on the refrigerant-side pressure drop of slit fin-tube heat exchanger has been carried out. A comparison was made between the predictions of previously proposed empirical correlations and experimental data for the pressure drop on design conditions of condenser in micro-fin tube for R22 and its alternatives, R407C (R32/125/134a, 23/25/52 wt.%) and R410A (R32/125, 50/50 wt.%). Experiments were carried out under the conditions of inlet refrigerant temperature of 6$0^{\circ}C$ and mass fluxes varying from 150 to 250 kg/$m^2$s for R22, R407C and R410A. The inlet air conditions are dry bulb temperature of 35$^{\circ}C$, relative humidity of 40% and air velocity varying from 0.68 to 1.43 m/s. Experiments show that pressure drop for R410A and R407C were 17.8∼20.2% and 5∼6.8% lower than those of R22 respectively for the degree of subcooling of 5$^{\circ}C$. For the mass fluxes of 200∼250 kg/$m^2$s, the deviation between the experimental and predicted values for the pressure drop was less than $\pm$20% for R22, R407C and R410A.

Experimental Study of Performance Characteristics of Various Fin Types for Fin-Tube Heat Exchanger

  • Youn, Baek;Kim, Young-Saeng;Park, Hwan-Young;Park, Hyun-Yeon
    • International Journal of Air-Conditioning and Refrigeration
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    • v.8 no.2
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    • pp.29-38
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    • 2000
  • Air side heat transfer and pressure drop for f 9.52 fin-tube heat exchanger with various types of slit and louver fins were measured, and compared with wave-slit fin. Longitudinal and transverse tube spacings of the heat exchangers are 21.65 mm and 25mm respectively. Actual heat exchanger was tested using water, and the tests were performed for 2 row heat exchangers with 3 different fin spacings, 1.3, 1.5 and 1.7 mm. The overall performance of the enhanced fins was evaluated by comparing heat transfer coefficient with respect to fan power

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Prediction of the Air-side Particulate Fouling in Finned-Tube Heat Exchangers of Air Conditioners used in the Field (실공간 사용 공기조화가용 열교환기의 공기측 파울링 특성 예측)

  • Hwang, Yu-Jin;Kim, Gil-Tae;Jeong, Seong-Il;Lee, Jae-Geun;Ahn, Young-Chull
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.306-310
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    • 2005
  • The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. An empirical modeling equation is derived from the experimental results using accelerated tests and it shows good predictions of the fouling characteristics of the slitted finned tube heat exchangers. However the modeling equation predicts only the fouling characteristics of new heat exchangers and it can not predicts fouling characteristics obtained from actual field data. The purpose of this study is to modify the previous modeling equation using the actual field data Therefore an modified modeling equation is proposed and it shows good predictions of the actual fouling characteristics of finned-tube heat exchangers.

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Modeling of Pressure Drop for Water Vapor Flow across Tube Banks inside Horizontal Tube Absorber

  • Phan Thanh Tong;Yoon Jung-In;Kim Eun-Pil
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.4
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    • pp.483-493
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    • 2006
  • A model for a pressure drop of water vapor flow across tube banks in a horizontal tube absorber of an absorption chiller/heater using LiBr solution as a working fluid has been developed based on a commercial 20RT(70kW) absorption chiller/heater. The numerical results show that the characteristic of the pressure drop in the shell side of the horizontal tube absorber is completely different from that in a conventional shell and tube heat exchanger. Especially, solution film thickness has significant influence on the vapor pressure drop in the horizontal tube absorber. In addition, the effects by the tube diameters, the longitudinal pitch to diameter ratio, and Reynolds number of the vapor flow, on the vapor pressure drop have been studied to evaluate the compactness of tube absorber. It was found that the vapor pressure drop decreases as tube diameter increases, the longitudinal pitch to diameter ratio increases, and Reynolds number of the vapor flow decreases. A comparison of the present study results with well-established experimental and numerical results showed a good overall agreement.

Heat Transfer and Pressure Drop Characteristics in Zigzag Channel Angles of Printed Circuit Heat Exchangers (지그재그채널 PCHE의 각도에 따른 열전달 및 압력강하특성)

  • Kwon, Oh-Kyung;Choi, Mi-Jin;Choi, Young-Jong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.9
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    • pp.475-482
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    • 2009
  • The objectives of this paper are to study the characteristics of heat transfer and pressure drop of the zigzag channel PCHE using diffusion bonding technology by numerical analysis. PCHE of five types are designed, which are zigzag channel angle 180$^{\circ}$, 160$^{\circ}$, 140$^{\circ}$, 120$^{\circ}$ and 100$^{\circ}$. The zigzag PCHE was numerically investigated for Reynolds number in a range of 150$\sim$800. The temperatures of the hot side were performed at 80$^{\circ}$ while that of the cold side was conducted at 20$^{\circ}C$. The results show that the performance of heat transfer rate for zigzag channel 100$^{\circ}$ increases about 11.5% compared to that of zigzag channel 180$^{\circ}$. On the other hand, the performance of pressure drop for zigzag channel 100$^{\circ}$ is remarkably higher than that of zigzag channel 180$^{\circ}$, about 2.4 times.

Experimental study of Heat Transfer and Pressure Drop Characteristics for the Welded Plate Heat Exchanger (용접형 판형 열교환기의 열전달 및 압력강하 특성에 관한 실험적 연구)

  • Jeong, Jong-Yun;Kim, Sung-Soo;Kang, Yong-Tae
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.419-424
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    • 2008
  • Heat transfer and pressure drop characteristics of welded plate heat exchanger are studied to apply it for the solution heat exchanger of 210RT absorption system. This study quantifies the effect of mass flow rate and strong solution concentration on the heat transfer coefficient and pressure drop in the plate heat exchanger. The concentration of weak solution is fixed at 55% and the strong solution varies 55%, 57%, and 59% in mass. The results show that the overall heat transfer coefficient and pressure drop increase linearly with increasing Reynolds number. It is also found that the heat transfer coefficient of hot side increases with increasing the concentration of strong solution while the strong solution concentration has no effect on heat transfer coefficient of cold side.

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A Study on Heat Transfer Characteristics in the Air Side of Louvered Fin Heat Exchanger (루우버핀형 열교환기의 공기측 열전달 특성에 관한 연구)

  • Kim, Sun-Jung
    • Journal of the Korean Solar Energy Society
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    • v.23 no.1
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    • pp.9-16
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    • 2003
  • For the study of an effect that fin thickness and shape of heat exchanger have on the elevation of heat transfer efficiency, we make models of plate fin type heat exchanger and louvered fin type heat exchanger which was given a transformation of fin thickness in plate f)n type heat exchanger and louvered fin type heat exchanger which are often used now. And the effect of fin thickness on pressure drop and characteristics of heat transfer was experimented and analysed when air velocity and temperature of plate heating was a variable. The results of experiment shows below. Pressure drop shows larger in louvered fin type exchanger than in plate fin type exchanger, size of pressure drop shows like this order that fin thickness is 0.3mm, 0.2mm, 0.1mm. Mean heat transfer coefficient shows higher in louvered fin type exchanger than in plate fin type exchanger, size of mean heat transfer coefficient by fin thickness shows same in both case in louvered fin type heat exchanger and plate fin type exchanger like this order that fin thickness is 0.1mm, 0.2mm, 0.3mm.

An Experimental Study on Performance Characteristic of 30RT Closed-Type Hybrid Cooling Tower using Bare Tube (베어관을 이용한 30RT급 하이브리드 밀폐형 냉각탑의 성능특성에 관한 실험적 연구)

  • Jun, Chul-Ho;Lee, Ho-Saeng;Moon, Choon-Geun;Kim, Jae-Dol;Yoon, Jung-In
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.1096-1101
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    • 2005
  • In this study, the experiment of thermal performance about closed-type hybrid cooling tower was conducted. A closed type cooling tower is a device similar to a general cooling tower, but with cooling tower replaced by a heat exchanger. The test section for this experiment has the process that the cooling water flows from top part of heat exchanger to bottom side in the inner side of tube, and spray water flows gravitational direction in the outer side of it. Air contacts of tube outer side are counterflow. The heat transfer pipe used in this experiment is a bare type tube having an outside diameter of 15.88mm. In this experiment, heat performances of the cooling tower are calculated such as overall heat transfer coefficient of between the process fluid and air, cooing capacity and pressure drop.

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