• Title/Summary/Keyword: 토출 압력

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유압베인펌프의 마찰특성

  • 정재연;이종순;김장현;이봉구
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1989.06a
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    • pp.22-28
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    • 1989
  • 유압베인펌프는 토출유량이 많고 소형으로 동력밀도는 높으나 토출압력면에스는 피스톤식 펌프에 뒤지기 때문에 발생압력의 고압화에 대한 연구가 계속되어 왔다. 유압장치의 경제적인 압력으로서 $300kgf/cm^2$가 제시되어 있는 가운데, 유압베인펌프의 고압화의 연구가 진행중에 있는 점, 또한 최근들어 에너지 절약의 일환으로 펌프의 수명연장 문제가 거론되어 지고 있는 점, 물에 타기 어려운 난연성유압 작동유를 사용할 경우 마찰증대 및 마모성능이 저하하는 점 등의 이유에서 유압베인 펌프의 마찰, 윤활문제가 중요시 되어지고 있다. 특히 펌프의 체적효율을 높이는 것과 마찰, 마모를 저하시키는 것과는 서로 상반된 관계에 놓여있기 때문에 문제의 해결에 어려움을 갖고 있다. 이와같은 모순을 해결하기 위해서는 베인과 캠링사이의 슬라이딩부분의 윤활상태를 파악하지 않으면 안된다. 그러나 베인의 선단부에는 10-20ms의 짧은 시간동안에 수백기압의 압력이 변화하기 때문에 지금까지 확실한 작용력의 파악이 어려워 이 분야의 윤활상태 파악에 관한 연구는 거의 이루어지지 않고 있다. 베인과 캠링간의 윤활상태를 윤활공학적 관점에서 보면 변동하중 상태에서의 슬라이딩 탄성유체윤활상태 또는 혼합윤활상태에 있는 것으로 판단되어지는데, 이와같은 여러가지 어려운 조건 때문에 윤활상태를 파악하는데, 어려운점이 뒤따르게 된다. 위와 같은 배경에 착안하여 본 연구에서는 유압베인펌프를 모델화하여 변동하중상태에서 실험이 가능한 장치를 제작, 사용하여 베인 선단 슬라이딩부분의 윤활상태를 파악하였다.

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A Study on the Effects of Various Disk Shape of Hydrant on the Pressure Drop (옥외소화전의 디스크 형상을 고려한 압력손실에 관한 연구)

  • You, Woo Jun;Shim, Myoung Gyu;Sung, Kun Hyuk;Yu, Jae Bum;Youm, Moon Cheon;Ryou, Hong-Sun
    • Fire Science and Engineering
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    • v.27 no.6
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    • pp.1-7
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    • 2013
  • In this study, the effects of various disk shapes of hydrant on the pressure drop are experimentally and numerically analyzed. The test methods for measuring pressure drop of hydrant are comply with standard of Underwriters Laboratory (UL). The hydrant as used in this study has one inlet, diameter 150 mm, and three outlet, 114.3 mm diameter for one outlet and 63.5 mm diameter for the others. The pressure of the hydrant are measured in the range 760 L/min~2,270 L/min for 63.5 mm outlet and 3,030 L/min~6,060 L/min for 114.3 mm outlet. Also, the numerical results of pressure drop are compared with the experiments to verify the accuracy and to analyze the of various valve shape of hydrant on the pressure drop. The engineering parameters, flow coefficients, are reduced from 181.57 to 136.35 ($L/min/kPa^{0.5}$) with inclined angle of disk from $0^{\circ}$ to $45^{\circ}$. These results are able to practical use for design hydrant to minimize pressure drop.

냉각재상실사고시 질량 및 에너지 방출량 감소를 위한 고찰

  • 허재영;이남호;정재훈;권영민;이상종
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.399-404
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    • 1996
  • 1000MWt 급 가압경수로의 질량 및 에너지 방출량을 감소시키기 위한 방안으로 울진 3,4호기를 기준으로 안전주입계통의 형태 및 용량을 변화시키면서 원자로냉각재펌프 토출관 및 고온관 파단에 대한 질량 및 에너지 방출량 계산과 격납건물 첨두압력 및 온도의 민감도를 분석하여, 후속호기 설계에 활용하고자 한다. 분석한 여러 경우 중에서, 토출관 파단사고시 안전주입탱크 용량은 변화시키지 않고 고압안전주입펌프 용량을 l75%로 증가시키면서 저압안전주입펌프를 제거하였을 경우가 격납건물 첨두압력 및 온도가 61.98 psia (3.32 kg/$\textrm{cm}^2$A), 288.03 ℉ (142.24$^{\circ}C$)로써 가장 낮게 나타났다. 이러한 결과는 격납건물의 설계여유도를 기존보다 더 확보하므로 안전성이 향상 될 뿐만 아니라. 저압안전주입펌프를 안전주입계통에서 제외함으로써 발전소 운전에도 큰 도움이 될 것이다.

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The Analysis of Discharge Pressure Noise Characteristics Of Vane Pump for Automatic Transmission (자동변속기용 베인펌프의 토출압 노이즈 특성 해석)

  • Choi, Y.Y.;Choi, H.J.;Lee, S.H.;Jung, W.J.
    • 유공압시스템학회:학술대회논문집
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    • 2010.06a
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    • pp.33-38
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    • 2010
  • As for an oil hydraulic vane pump of vehicle hydraulic systems, the highest of planning technique required by the acquisition of optimum profile data which can be available to predict noises and vibrations. Pressure pulsation may result in considerable vibration and noise of pump component as well as cavitation in hydraulic system. The influences of the discharge pressure and rotating speed of the vane on the dynamic pressure in chamber surrounding a vane have been investigated. It is very important to predict pressure pulsation in vane pump. This paper presents analysis of technique of vane pump for automatic transmission. The predicted result using AMESim model were good agreement with the experimentally obtained results.

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Pressure Pulsation Characteristics of a Multiple-Delivery Radial Piston Hydrulic Pump (다중 토출 레이디얼 유압 피스톤 펌프의 압력 맥동 특성)

  • Choi, S.R.;Lim, J.C.;Lee, I.Y.
    • Journal of Drive and Control
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    • v.11 no.2
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    • pp.1-8
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    • 2014
  • In this study, the authors carried out experiments and numerical simulations in order to clarify the pressure pulsation characteristics in multiple-delivery rotating-cam and stationary-cylinder type radial piston pumps. Also, a tee filter was applied to the pump in order to mitigate the pressure pulsation. Through the experiments and simulations, it was known that pressure pulsation with a magnitude higher than 40% of the mean load pressure could occur in the pump used in the experiments. Moreover, it was confirmed that a tee filter designed in this study could effectively mitigate the pressure pulsation.

The Enhanced LED Dispensing Processing System (개선된 LED 토출 공정 시스템)

  • Cho, Do-Hyeoun;Lee, Jong-Yong
    • 전자공학회논문지 IE
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    • v.45 no.4
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    • pp.42-46
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    • 2008
  • LED's production does Die bonding and Wire bonding on L/F board, and do epoxy dispensing to protect LED Chip and improve brightness. In this paper, we propose and realize a x-y-z axis robot mechanism detecting automatically eopxy's amount being filled, control data of pressure and time by the quantity automatic revision, and epoxy of the schedule amount dispensing.

A Study on Fluid Flow Analysis of High Pressure Positive Displacement Pump without Clearance (클리어런스가 없는 초고압 회전용적형 헬리컬기어 펌프의 유동해석에 관한 연구)

  • Min, Se-Hong;Kim, Ho-Chul
    • Fire Science and Engineering
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    • v.29 no.2
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    • pp.33-38
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    • 2015
  • For the purpose of high-pressure and suction of fixed amount, the development of ultra-high pressure rotating helical gear positive displacement pump with no clearance had been proceeded. The CFD analysis was performed to verify the internal pressure and the discharge flow velocity of the pump. Accordingly, a flow analysis were performed by FVM technique and we were unable to obtain a successful result since the fluid domain is separated because the grid is not configured in a row in FVM flow analysis of the fully enclosed type without clearance. Because of these problems, the flow analysis was performed by MPS method which grid configuration is not needed and the internal pressure and the discharge flow velocity of the pump were confirmed through the MPS flow analysis. At 1,000 rpm rotation speed of the rotor, the minimum internal pressure of the pump was 19.5 bar, maximum pressure was 44.6 bar and average pressure was 33.9 bar. And the minimum discharge flow velocity was 64.5 m/s, maximum discharge flow velocity was 84.8 m/s and average discharge flow velocity was 76.1 m/s. Through this study, we could confirm that MPS method was more suitable than FVM method in terms of flow analysis with no clearance. In addition, the relationship of the flow velocity according to the change of ultra-high pressure rotating helical gear positive displacement pump could be identified through this study.

A Study on Performance Characteristics of the Developed Fuel Pump for a Single-cylinder Four-stroke Agricultural Diesel Engine (단기통 4행정 농용 디젤기관의 개발 연료펌프 성능특성에 관한 연구)

  • Bae, Myung-whan;Lee, Sang-hae;Jung, Hwa
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.9
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    • pp.756-761
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    • 2016
  • The objective of this study is to design and manufacture a fuel pump with the plunger diameter of 4 mm and stroke of 7 mm that can be mounted in a small single-cylinder four-stroke agricultural diesel engine, and to investigate the performance characteristics of the pump. The combustion pressure in a cylinder was reproduced by forming the back pressure of 1, 6, 11, 16 and 21 bar with a nitrogen gas in the home-manufactured modeling cylinder. In the experiment, the discharge pressure was measured at the spot of 1 cm away from the discharge port of a developed fuel pump. The delivery pressure and delivery flow rate were measured at the spot of 30 cm away from the discharge port of the pump, and the pump efficiency was calculated. The pump motor speed was changed from 600 to 800, 1000, 1200 and 1400 rpm. It is found that the delivery feed rate of fuel pump is increased as the rotational speed is raised, and is decreased as the back pressure, compression pressure in the cylinder, is increased. Also, the pump efficiency is reduced as the rotational speed and back pressure are increased.

Study on Nozzle Type and Proper Discharge Pressure of Sprayer for Vehicle Disinfecting System (차량소독장치용 노즐형태와 분무기의 적정토출압력에 관한 연구)

  • Lim, Young-Il;Chang, Dong-Il;Kim, Jeong-Chul;Park, Dong-Suk;Lee, Seung-Joo;Kang, Beom-Sun;Kim, Suk;Gutierrez, Winson M.;Lee, Tae-Hoon;Choi, Chung-Heon;Chang, Hong-Hee
    • Journal of agriculture & life science
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    • v.50 no.3
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    • pp.119-127
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    • 2016
  • The current disinfection method of vehicles being applied in South Korea has various shortcomings. So, the epidemic has generated continuously at livestock farms. It is very important to develop an effective disinfection system for reduction of the epidemic. And various basic data is required for this development. Therefore, this study was performed to identify the nozzle type and proper discharge pressure of sprayers. The experiment was conducted from January 10, 2012 until February 28, 2012. All the performance measurement experiments were repeated five times. The subjects of experiment were the A, B and C company's products. The sprayed capacity, angle of spray and the covering area ratio were measured for each product. As a result, the sprayed capacity, angle of spray and the covering area ratio were increased as the discharge pressure of the sprayer was increased. In conclusion, the conical shaped of the nozzle is considered more appropriate than V-shaped, and the proper discharge pressure is expected to be at least 20kg/㎠.

A study on the improvement of process operation through the adjustment to the flow rate of LNG HP pump (LNG 고압펌프 운전유량 조절에 따른 공정운영 개선방안 연구)

  • Kim D. H.;Lee J. H.;Kim H, Y.;Baek Y. S.
    • Journal of the Korean Institute of Gas
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    • v.8 no.4 s.25
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    • pp.15-22
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    • 2004
  • This study has been carried out to improve the conditions of process operation through the adjustment to the flow rate and outlet pressure of LNG HP pump, one of the main process facilities, in LNG receiving terminal. We have determined optimum flow rate and applied it to the field operation by analyzing the field operating performance for all the HP pumps and the load of natural gas supply in seasonal using the ASPEN PLUS. As a results, we have get the electric cost saving for the HP pump operation and derived contribution to safety operation by reduced the LNG Process pressure.

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