• Title/Summary/Keyword: high-pressure gas valve

Search Result 107, Processing Time 0.031 seconds

Flow capacity test of spring load safety relief valves used in LNG (LNG 선박용 spring load 안전방출밸브의 유량 성능시험)

  • Park, Kyung-Am;Lee, Saeng-Hee;Kim, Keng-Kuen;Goh, Jang-Hoon
    • 유체기계공업학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.95-98
    • /
    • 2006
  • Many LNG ships will be constructed in Korea and the demand of safety valves is increasing. The most important performance of the developed safety relief valves for LNG ship is flow capacity. Flow capacity tests for 8 sizes of developed safety valves were conducted in the high pressure gas flow standard system in KRISS. The initial spring force adjustment was important for setting pressure of the safety valve. The procedure of data reduction and evaluation of the safety valve performance are suggested. This procedure was approved by French Bureau Veritas and Lloyd's Register.

  • PDF

A Study on the Thermal Characteristics of the Vacuum Jacket Valve for Transporting Liquefied Hydrogen According to the Degree of Vacuum (액화수소 수송용 진공자켓 밸브의 진공도에 따른 열적특성에 대한 연구)

  • OH, SEUNG JUN;JEON, KYUNG SOOK;YOON, JEONG HWAN;CHOI, JEONGJU
    • Journal of Hydrogen and New Energy
    • /
    • v.32 no.6
    • /
    • pp.585-591
    • /
    • 2021
  • Liquefied hydrogen have advantage which reduces the volume by about 800 times or more compared to hydrogen gas, so it is possible to increase the storage density. However, liquefied hydrogen produced by cryogenic cooling of 20 K or less at normal pressure has a problem of maximizing the insulation effect that blocks heat introduced from the outside. Representative insulation technologies include vacuum insulation and multi-layer insulation materials and in general, heat blocking is attempted by combining insulation technologies. Therefore, in this study, the pressure of the internal vacuum layer was changed to 10-1, 10-2, 10-3 and 10-4 Torr to confirm the thermal insulation performance of the vacuum jacket valve for transporting liquefied hydrogen. As a result, it was confirmed that the insulation performance improved as the degree of vacuum increased.

Experimental Study on Single Channel DPF Device Applying the Method of Internal 2-Way Rotary Valve (회전형 밸브를 적용한 단일채널내 2-Way 방식의 DPF장치에 대한 실험적 연구)

  • Ham, Seong-Hun;Youm, Kwang-Wook
    • Journal of the Korean Institute of Gas
    • /
    • v.19 no.6
    • /
    • pp.110-115
    • /
    • 2015
  • In this paper it is proposed to solve the problem of particulate matter reducing apparatus of the current DPF. One exhaust gas passage 2-way controlled to purify the exhaust gas generated during combustion efficiently. Through the control of the rotary valve within a single device, it is possible to prevent the exhaust pressure increases due to particulate matter accumulate inside the developing DPF. Develop DPF device capable of inducing a high efficiency of the output in order to improve the problem of reducing the engine output and fuel efficiency.

Numerical investigation into flow noise source of a convergent-divergent nozzle in high pressure pipe system using wavenumber-frequency analysis (파수-주파수 분석을 통한 고압 배관 내 수축 확장 노즐의 유동 소음원에 대한 수치적 연구)

  • Ku, Garam;Lee, Songjune;Kim, Kuksu;Cheong, Cheolung
    • The Journal of the Acoustical Society of Korea
    • /
    • v.36 no.5
    • /
    • pp.314-320
    • /
    • 2017
  • A pressure relief valve is generally used to prevent piping systems from being broken due to high pressure gas flows. However, the sudden pressure drop caused by the pressure relief valve produces high acoustic energy which propagates in the form of compressible acoustic waves in the pipe and sometimes causes severe vibration of the pipe structure, thereby resulting in its failure. In this study, internal aerodynamic noise due to valve flow is estimated for a simple contraction-expansion pipe by combining the LES (Large-Eddy Simulation) technique with the wavenumber-frequency analysis, which allows the decomposition of fluctuating pressure into incompressible hydrodynamic pressure and compressible acoustic pressure. In order to increase the convergence, the steady Reynolds-Averaged Navier-Stokes equations are numerically solved. And then, for the unsteady flow analysis with high accuracy, the unsteady LES is performed with the steady result as the initial value. The wavenumber-frequency analysis is finally performed using the unsteady flow simulation results. The wavenumber-frequency analysis is shown to separate the compressible pressure fluctuation in the flow field from the incompressible one. This result can provide the accurate information for the source causing so-called acoustic-induced-vibration of a piping system.

A Forging Analysis and Mechanical Properties Evaluation of Superalloy Exhaust Valve Spindle (초내열 합금 배기 밸브 스핀들 단조 해석 및 기계적 특성 평가)

  • Choi, S.G.;Oh, J.S.;Jeong, H.S.;Cho, J.R.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2009.10a
    • /
    • pp.84-88
    • /
    • 2009
  • The nickel-based alloy Nimonic 80A possesses strength, and corrosion, creep and oxidation resistance at high temperature. The exhaust valves of low speed diesel engines are usually operated at temperature levels of 400-$600^{\circ}C$ and high pressure to enhance thermal efficiency and exposed to the corrosion atmosphere by the exhaust gas. Also, the exhaust valve is subjected to repeated thermal and mechanical loads. So, the nickel-based alloy Nimonic 80A was used for the large exhaust valve spindle. It is composed a 540mm diameter head and a 125mm diameter stem. It is developed large products by hot closed-die forging. Manufacturing process analysis of the large exhaust valve spindle was simulated by closed die forging with hydraulic press and cooled in air after forging. The preform was heated to $1080^{\circ}C$ Numerical calculation was performed by DEFORM-2D, a commercial finite element code. Heat transfer can be coupled with the deformation analysis in a non-isothermal deformation analysis. Mechanical properties of the large exhaust valve spindle were evaluated by the variety of tests, including microstructure observation, tensile, as well as hardness and fatigue tests, were conducted to evaluate the mechanical properties for head part of exhaust valve spindle.

  • PDF

Design Concept of Hybrid SIT (복합안전주입탱크(Hybrid SIT) 설계개념)

  • Kwon, Tae-Soon;Euh, Dong-Jin;Kim, Ki-Hwan
    • The KSFM Journal of Fluid Machinery
    • /
    • v.17 no.6
    • /
    • pp.104-108
    • /
    • 2014
  • The recent Fukushima nuclear power plant accidents shows that the core make up at high RCS pressure condition is very important to prevent core melting. The core make up flow at high pressure condition should be driven by gravity force or passive forces because the AC-powered safety features are not available during a Station Black Out (SBO) accident. The reactor Coolant System (RCS) mass inventory is continuously decreased by releasing steam through the pressurizer safety valves after reactor trip during a SBO accident. The core will be melted down within 2~3 hours without core make up action by active or passive mode. In the new design concept of a Hybrid Safety Injection Tank (Hybrid SIT) both for low and high RCS pressure conditions, the low pressure nitrogen gas serves as a charging pressure for a LBLOCA injection mode, while the PZR high pressure steam provides an equalizing pressure for a high pressure injection mode such as a SBO accident. After the pressure equalizing process by battery driven initiation valve at a high pressure SBO condition, the Hybrid SIT injection water will be passively injected into the reactor downcomer by gravity head. The SBO simulation by MARS code show that the core makeup injection flow through the Hybrid SIT continued up to the SIT empty condition, and the core heatup is delayed as much.

Numerical Analysis for Evaluation of Ejection Capacity Relationship of Safety Valves in Pressure Regulating Station(I) - Flow Analysis and Mass Flow Rate Verification of Pressure Regulator - (정압기지내의 안전밸브 분출용량 관계식 검증을 위한 유동해석(I) - 정압기 유동 해석 및 질량 유량 검증 -)

  • Gwon, Hyuk-Rok;Roh, Kyung-Chul;Kim, Young-Seop;Lee, Seong-Hyuk
    • Journal of the Korean Institute of Gas
    • /
    • v.12 no.2
    • /
    • pp.99-104
    • /
    • 2008
  • Gas pressure regulators in pressure regulating station reduce high-pressure gas in a process line to a lower. Gas pressure regulators are not flow control devices, they are used to control delivery pressure only. For the safety of pressure regulating station, it is essential to study flow regime and characteristics of a safety valves that is connected to a pressure regulator. For this, it is necessary to understand flow characteristics and the flow rate of upstream component part such as gas pressure regulators in regulating station. In the present study, numerical analysis of flow characteristics and the mass flow rate of a pressure regulator is conducted under the several inlet, outlet conditions and open rates. Then, the numerical result of the mass flow rate is verified with experimental equation from manufacture of pressure regulator. Consequently, the numerical result is comparatively good agreement with values from experimental equation.

  • PDF

Finite Element Analysis of Rod and Inside of Chamber of High Pressure Pump for Liquid Hydrogen (액화수소 고압 펌프 Rod 및 챔버 내부 유한요소해석)

  • Hyunse Kim;Young-Bog Ham;Jung-Ho Park
    • Journal of the Korean Institute of Gas
    • /
    • v.28 no.2
    • /
    • pp.32-37
    • /
    • 2024
  • Recently, transportations using hydrogen energy is being researched for the alternative energy of fossil fuels. To use them, processes of producing, storing and transferring are required. When carrying them in liquid under 90 MPa pressure, it costs less than in a gas status. Thus, a hydrogen pump is necessary and in this research we predicted the flow in the chamber using finite element methods (FEM) program ANSYS. As a result, when the valve was opened by 3 mm, between the 1st chamber and the 2nd chamber, the maximum velocity was decreased to 8.111 m/s by 10.6% (without valve, 9.075 m/s). In addition, pressure was also increased to 0.63 MPa by 1.6% (without valve, 0.62 MPa). When using these results, more efficient processes would be possible in designing them in detail.

Design of a Cylinder Valve Solenoid for a CNG Vehicle using Electromagnetic Field Analysis (전자기장 해석을 이용한 CNG 차량 용기용 밸브 솔레노이드의 설계)

  • Lee, Hyo-Ryeol;Ahn, Jung-Hwan;Shin, Jin-Oh;Kim, Hwa-Young
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.15 no.2
    • /
    • pp.89-96
    • /
    • 2016
  • Growing concerns regarding environmental pollution have increased the demand for green vehicles. Green vehicles include electric vehicles, compressed natural gas vehicles, fuel cell vehicles, and vehicles running on fuels such as bio diesel or an ethanol blend. CNG vehicles are equipped with a cylinder valve installed in a high-pressure vessel to control the CNG flow. For this purpose, the optimum design of cylinder valve solenoid is necessary to secure at driving a CNG vehicle. In this study, electromagnetic field analysis to ensure the reliable operation of the solenoid was conducted by using a Maxwell V15. The electromagnetic field analysis was performed by magnetostatic technique according to distance between magnetic poles in order to predict the attraction force. Finally, the attraction force was validated through comparison between the Maxwell results and the measurement results. From the results, the error of attraction force was found to be 2.85 N to 6.5 N under the testing conditions.

Risk Reduction Rate for Each Risk Mitigation Measure on High Pressure Urban Gas Pipelines Proposed by Quantitative Risk Analysis (정량적 위험성 평가를 통해 제안된 도시가스 고압배관의 위험경감조치별 위험감소효과)

  • Ryou, Young-Don;Jo, Young-Do;Park, Young-Gil;Lee, Su-Kyung
    • Journal of the Korean Institute of Gas
    • /
    • v.14 no.4
    • /
    • pp.18-23
    • /
    • 2010
  • After conducting QRA(quantitative risk assessment) for the high pressure urban gas pipelines planned to be installed, RMMs(risk mitigation measures) when the societal risk is outside the acceptable region have been derived in this paper. Also risk reduction rates are calculated for each RMM. As a result of QRA, we find out that damaged distance caused by radiational heat is largely dependent upon the wind velocity and the atmospheric stability. The measure that has the highest risk reduction effect is No. 10 which includes pipeline corrosion monitoring, MOV(motor operated valve) installation and the method to protect pipeline damage caused by third-party mechanical interference, and which shows 75 % of risk reduction effect.