• Title/Summary/Keyword: Drop-in Test

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Pressure Drop of a Gasket Sealed Plate Type Heat Exchanger upon its Operating Conditions (Gasket 방식 판형 열교환기의 고.저온부 유량 및 압력차에 따른 압력강하 특성)

  • Ahn, Joon;Kim, Hyouck-Ju;Choi, Kyu-Sung;Song, Dae-Seok
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.189-194
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    • 2009
  • In a gas engine based cogeneration system, heat is recovered from two parts, which are jacket water and exhaust gas. The heat from the jacket water is often recovered by a plate type heat exchanger and used for the room heating and/or hot water supply. Depending on the operating conditions of engine and heat recovery system, there should be imbalance in the flow rate and supply pressure between engine and heat recovery side of the heat exchanger. The imbalance cause the deformation of the plate, which affects the pressure drop characteristics. In the present study, the pressure drop inside the heat exchanger has been investigated in a 1/5 scaled test rig and compare with the experimental correlations, which are used for the design.

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Forced Convection Characteristics of V shape Circular fin-tube Heat Exchanger (V형 원형휜-원형관의 강제대류 열유동 특성)

  • Lee, Jong-Hwi;Lim, Moo-Gi;Kang, Hie-Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.12
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    • pp.649-655
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    • 2009
  • The purpose of the present study is to investigate the flow resistances and heat transfer characteristics of V-shaped circular fin-tube heat exchangers. Four types of V-shaped fins in which the fin areas are identical but the areas of the V-shaped portion are different have been tested numerically. The results obtained for heat transfer, pressure drop, and fin temperature are discussed in this paper. With increase in the area of the V-shaped portion, the pressure drop and heat transfer increase up to 40% and 24%, respectively, in the present test range.

Effects of Sensor Errors in Air Cleaner Testing on the Cleaner Performance Estimation (공기청정기 시험기의 센서신호 오차가 공기청정기 성능 평가에 미치는 영향)

  • CHUNHWAN LEE;MINYOUNG KIM;SUMIN LEE
    • Journal of Hydrogen and New Energy
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    • v.34 no.1
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    • pp.77-82
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    • 2023
  • The fuel cell in fuel cell electric vehicle utilizes oxygen in the atmosphere, which requires the use of an air cleaner system to minimize the intake of harmful pollutants. To estimate the performance of the air cleaner system, the pressure drop between the filter inlet and outlet is used under the rated air flow condition. In this study, the effect of sensor error in this air cleaner testing is experimentally carried out. It is found that the errors of the temperature sensor does not significantly affect the estimation of pressure drop. However, in the case of the pressure sensor, 5% sensor error results in the error of pressure drop estimation by 3%. Therefore, it is recommended that the measurement accuracy of the pressure sensor mounted in test system should be maintained at less than 5%.

Performance Test of Pressure and Flow Rate in a Hot-Water Heating System with 3-Way Valves for Flow Bypass (바이패스용 3-Way 밸브를 장착한 온수 난방시스템의 압력 및 유량 특성 평가)

  • Hur, Jurn;Lee, Suk-Jong;Sung, Jae-Yong;Lee, Myeong-Ho;Yoon, Jai-Dong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.3
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    • pp.269-274
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    • 2007
  • A 3-way valve has been applied to a distributor in a hot-water heating system and the performance of the system was evaluated in view of the variations of pressure drop and flow rate. The 3-way valve has been designed to bypass overplus hot-water when a control valve is closed. Note that the flow goes through heating pipeline in normal operation. In the present study, the measured pressure drops in each part of the flow paths show that the contribution to the total pressure drop is in the order of the supply header with control valves, piping system of each room and return header of the distributor, even though the amount of it is different according to the flow paths. As a result of performance test by sequential closing of the control valves, the variations of pressure drop and flow rate in the distributor with 3-way valves is much lower than those with previous 2-way valves, which prevent noises induced by pressure fluctuations.

A Study on Hydraulic Behavior and Mass Transfer by Absorption in Packing Tower (충전탑에서 흡수에 따른 물질전달과 수력학적 거동에 관한 연구)

  • 김석택
    • Journal of Environmental Science International
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    • v.9 no.5
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    • pp.393-396
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    • 2000
  • Packing tower has been used in the chemical industry and the protection of environment for a long time. In the view of environmental protection purification of exhaust gas can be performance effective by gas absorption in counter-current packing tower. In this study characteristics of hydraulic and mass transfer were investigated in D. 0.3m×H.1.4m packing tower with 50mn plastic Hiflow-ring. This study was carried out "Test systems were experimented in conditions of Air, Air/H2O.NH3Air/H2O,NH3Air/H2OH2SO4 and SO2Air/H2ONaOH under steady state" The extent of test included dry and wetting pressure drop physical law separation efficiency and hold-up as function of gas and liquid load.quid load.

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Heat Transfer and Pressure Drop of CO2 Gas Cooler in a Helically Coiled Tube (헬리컬코일형 CO2 가스쿨러의 열전달과 압력강하)

  • Kyoung, Nam-Soo;Yu, Tae-Guen;Son, Chan-Hyo;Oh, Hoo-Kyu
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.11a
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    • pp.246-247
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    • 2005
  • The paper presents the heat transfer characteristics during cooling process of carbon dioxide(CO2) in a helically coiled tube. The main components of the apparatus consist of a receiver, a variable speed pump, a mass flowmeter, a pre-heater, a gas cooler(test section) and an isothermal tank. The test section with the inner diameter 4.55 [mm] is a tube in tube type heat exchanger with refrigerant flowing in the inner tube and water flowing in the annulus. The main results were summarized as follows : The heat transfer coefficient increases with respect to the decrease of the gas cooler pressure in a supercritical region and the increase of the refrigerant mass flux. The pressure drop decreases in increases of the gas cooler pressure and increases with respect to increases the refrigerant mass flux.

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Incipient Cavitation in a Bulb Turbine: Model Test and CFD Calculation

  • Necker, Jorg;Aschenbrenner, Thomas
    • International Journal of Fluid Machinery and Systems
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    • v.4 no.1
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    • pp.140-149
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    • 2011
  • For a certain operating point of a horizontal shaft bulb turbine (i.e. volume flow, net head, blade angle, guide vane angle) the efficiency for different pressure levels (i.e. different Thoma-coefficient σ) is calculated using a commercial Computational Fluid Dynamics (CFD-)-code including two-phase flow and a cavitation model. The results are compared with experimental results achieved at a closed loop test rig for model turbines. The comparison of the experimentally and numerically obtained efficiency and the visual impression of the cavitation show a good agreement. Especially the drop in efficiency is calculated with satisfying accuracy. This drop in efficiency in combination with the visual impression is of high practical importance since it contributes to determine the admissible cavitation in a bulb-turbine. It is seen that the incipient cavitation in Kaplan type turbines has no major importance in determing this admissible amount of cavitation.

The Influence of Walking on the Crural Muscle Tone and Stiffness in Pronated Foot

  • Wang, Joong San
    • Journal of International Academy of Physical Therapy Research
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    • v.9 no.2
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    • pp.1486-1489
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    • 2018
  • This study aimed to investigate the influence of walking on crural muscle tone and stiffness in individuals with bilateral pronated foot. This study consisted of 16 healthy male. Subjects were divided into a pronated foot group (n = 8) and a normal foot group (n = 8). The navicular drop test on both foot and muscle tone and stiffness in tibialis anterior muscle, medial gastrocnemius muscle, and peroneus longus muscle of both lower extremities were measured before and after 30 min of walking. In this study, the measured navicular drop test before walking was significantly different between pronated foot group and a normal group(p < .05). After 30 min of walking, significantly, increased medial gastrocnemius muscle stiffness of the non-dominant leg was found in the pronated foot group (p < .05). However, there was no significant difference in medial gastrocnemius muscle stiffness between the two groups (p > .05). Based on this study, pronated foot needs to be managed to prevent the abnormally increased medial gastrocnemius muscle stiffness.

A study on Automatic field Test Equipment with improved maintenance and environmental reliability

  • Lee, Seok-Min
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.3
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    • pp.9-16
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    • 2018
  • In this paper, I purpose one of the development methods for portable Automatic field Test Equipment(ATE) with VME form factor. Almost portable ATE have not used to standards form factor and they are connected by mechanical non-rigid general connectors and wire harnesses among the components. Furthermore, it is hard to reuse developed board. So, it decreases to reusability of developed board and it is hard to maintenance of ATE. Even those things have weakness for vibration and drop test especially in portable ATE. The XK9A1 ATE using VME form factor has environmental reliability through vibration, drop, temperature test. It consists of 5 developed board called the control board, the wire & wireless communication board, the power supply board, the load board and the mother board. It is connected by two wire harnesses between mother board and extern circular connectors. The control board send the data and address to other board though each 16-bit data and 20-bit address line. You can develop the function board what you want to using those data & address line when it comes to needing other function board.

The study on the Two-Phase Swirl Flow Characteristics in Cylindrical Pipe (원관내의 이상선회유동 특성에 관한 연구)

  • 차경옥;김재근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.1
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    • pp.187-197
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    • 1996
  • Many investigations have been made to determine the pressure drop and heat transfer characteristics for single phase flow in tape generated swirl flow. But few studies have been carried out to investigate the heat transfer in two component, two phase swirl flow with non-boiling. An experimental study has been conducted to determine the effects of tape twist ratios on two phase convective heat transfer coefficients, pressure drop, and void fraction distribution in a non-boiling, air-water, two phase flow. The flow conditions were both swirl and non swirl flows. The internal diameter of the test section is 42.5mm. The tape twist ratios of pitch to diameter ratio varied from 4.0 to 10.6. The heating conditions were isothermal and nonisothermal. The flow patterns identified with experiments were bubbly, bubbly-slug, slug, and slug-annular flow in up-flow. This study has concluded that no significant difference in void fraction distribution were observed both isothermal and nonisothermal conditions, the pressure drop for two phase flow with twisted tape swirler increase as the tape twist ratio decrease, and that values of two phase heat transfer coefficient increase when the tape twist ratio decreases.

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