• 대한안전경영과학회지
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• 제8권4호
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• pp.39-51
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• 2006

Based on the practical process engineering design and commissioning and startup operation experiences focused on chemical process safety, the comprehensive review of engineering design and installation of the thermal relief valve with its surrounding facility in a chemical plant piping system is provided to enhance the better understanding of the piping system of characteristics of thermal relief valve which is comprised of the theoretical approach, correlation in terms of temperature and pressure increase caused by external heat supply in a piping system, consideration of thermal relief valve engineering design, pressure relieving system of serial thermal relief valves and exception of their installation. It is earnestly suggested that following topic should be implemented during thermal relief valve engineering design, installation and normal operation as well.

• 항공우주시스템공학회지
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• 제13권4호
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• pp.50-59
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• 2019

플랩제어시스템의 주요 구성품인 주제어밸브의 설계는 실제 제작 경험을 바탕으로 반복-오차 방법에 의존하여 수행하였다. 본 논문에서는 모델 기반의 부품 설계 방법을 제안하였다. 플랩제어시스템은 주제어 밸브, 고장-안전 밸브, 솔레노이드 밸브, LVDT, 구동 모터 등으로 구성된다. 주제어밸브는 주로 스풀과 슬롯으로 구성된다. 주제어밸브의 중요한 설계변수는 슬롯의 폭 (Slot Width), 오버 랩(Overlap) 및 간극(Clearance)이다. AMESim을 활용하여 주 제어 밸브의 유로를 모델링하고 해석하였다. 제안된 설계절차를 적용한 결과 허용된 가공오차 범위 내에서 요구 성능을 충족함을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제19권1호
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• pp.28-35
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• 1995

The fluid flow for a energy transfer is essential for the design and operation of power plants, petrochemical plants and ships including a process. When the operating conditions of a plant are changed or any transitional event occured, the flow controls of a fluid must be performed to follow the new operating state or mitigate the results of a event. Generally these flow controls to accommodate the new operating state of a plant are made by the use of various valves. The refore the design of valves and the related techniques are very important to the system and component designs. However the system and component design are not familiar with the practical theory of the valve since the derivative procedures of the flow equations in a valve are difficult and it is not easy to found the theoretical foundamentals and informations about the design of a valve from the present references. In this study the flow equations applicable to a valve for liquid are theoretically derived in detail. And the definition of valve reynolds number and its boundary values between the tubulent and laminar flow is described compared with the values of a circular pipe flow.

• 대한기계학회논문집A
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• 제26권4호
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• pp.683-692
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• 2002

The most important parameter for hydraulic active suspension system is to sustain desirable vehicle maneuvering stability and ride comfort without increasing power consumption. The performance of hydraulic active suspension system depends on damping force of body damping valve and piston damping valve. Hydraulic actuator design and damping valve parameter selection are essential and basic procedure to design hydraulic system. This paper is on computer simulation with use of mathematical model that was delivered from dynamic characteristic of hydraulic actuator, as know basic damping characteristics of hydraulic active suspension system. The aim of this paper is to select the system parameter that affect mainly hydraulic active suspension, and identify the validity on the system parameter selection.

• International journal of advanced smart convergence
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• 제6권4호
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• pp.1-8
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• 2017

In this work, the effects of fairly influential factors on performance of vacuum system, such as constant pressure and outgassing effect were simulated to propose the optimum design factors. Outgassing effects of selected vacuum materials on the vacuum characteristics were simulated by the $VacSim^{Multi}$ simulation tool. This investigation examined the feasibility of reliably simulating the outgassing characteristics of common vacuum chamber materials (aluminum, copper, stainless steel, nickel plated steel, Viton A). The optimum design factors for vacuum systems were suggested based on the simulation results. And, the effects of throttle valve applications on vacuum characteristics were also simulated to obtain the optimum design model of variable conductance on high vacuum system. Simulated vacuum characteristics of the proposed modelling were agreed with the observed experimental behaviour of real systems. Pressure limit valve and normally on-off control valve were schematized as the modelling of throttle valve for the constant process-pressure. Simulation results were plotted as pump-down curve of chamber and variable conductance of throttle valve. Simulated behaviors showed the applications of throttle valve sustained the process-pressure constantly, stably, and reliably.

• 한국자동차공학회논문집
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• 제8권6호
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• pp.111-121
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• 2000

Generally, the hydraulic pressures are used for transmitting the force. Therefore, a highly reliable and inexpensive control system has been required for a passenger car. The control-ability of active suspension system is strongly affected by the performance of pressure control valve in the view of dynamic response and energy consumption. In this study, we suggested main design parameters for the optimum design of proportional pressure control valve. The mathematical simulation model was derived from the quarter type model which consisted a valve and hydraulic damper for the purpose of analyzing the valve characteristics. Experiments were performed to confirm the performance of the valve and computations were carried out to ascertain the usefulness of the developed program. The results from computations fairly coincide with those from experiments. This has been achieved by developing the servomechanism valve which comprises the simple combination of a solenoid, a spool valve and a poppet valve. The results from experiments and computations show the development process of optimum proportional pressure control valve in the hydraulics system.

• Journal of Mechanical Science and Technology
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• 제15권7호
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• pp.1061-1071
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• 2001

The present study investigated design parameters of shunt valves and anti-siphon device used to treat patients with hydrocephalus. The shunt valve controls drainage of cerebrospinal fluid (CSF) through passive deflection of a thin and small diaphragm. The anti-siphon device(ASD) is optionally connected to the valve to prevent overdrainage when the patients are in the standing position. The major design parameters influencing pressure-flow characteristics of the shunt valve were analyzed using ANSYS structural program. Experiments were performed on the commercially available valves and showed good agreements with the computer simulation. The results of the study indicated that predeflection of the shunt valve diaphragm is an important design parameter to determine the opening pressure of the valve. The predeflection was found to depend on the diaphragm tip height and could be adjusted by the diaphragm thickness and its elastic modulus. The major design parameters of the ASD were found to be the clearance (gap height) between the thin diaphragm and the flow orifice. Besides the gap height, the opening pressure of the ASD could be adjusted by the diaphragm thickness, its elastic modulus, area ratio of the diaphragm to the flow orifice. Based on the numerical simulation which considered the increased subcutaneous pressure introduced by the tissue capsule pressure on the implanted shunt valve system, optimum design parameters were proposed for the ASD.

• 한국기계가공학회지
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• 제9권5호
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• pp.7-13
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• 2010

Main starting valve is one of the main parts in the control system of diesel engines, purposed for starting main engines. It is composed of ball valve, check valve, actuator, etc. The design axioms provide a general framework for design methodology. Two axioms are independence axiom and information axiom. These axioms can be applied to all design process in a general way. The first axiom is introduced to analyze and evaluate the design of a main starting valve. The design parameters(DPS) are determined sequentially by considering the independence axiom. For the structural design of a main starting valve, the strength is calculated by using finite element method. In addition, the strength of its actuator piston is evaluated.

• 드라이브 ㆍ 컨트롤
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• 제16권1호
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• pp.29-35
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• 2019

The control performance of hydraulic systems is basically influenced by the performance of electrohydraulic servo valve incorporated in a hydraulic control system. In this study, a control design was proposed to improve the control performance of a servo valve with a non-contact eddy current type position sensor. A mathematical model for the valve was obtained through an experimental identification process. A PI-D control together with a feedforward (FF) control was applied to the valve. To further improve the dynamic response of the servo valve, an input shaping filter (ISF) was incorporated into the valve control system. Finally, the effectiveness of the proposed control system was verified experimentally.

• International Journal of Fluid Machinery and Systems
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• 제9권1호
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• pp.28-38
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• 2016

The flexible control system for hydraulic pile hammer using main control valve is present to the requirement of rapidly reversing with high frequency. To ensure the working reliability of hydraulic pile hammer, the reversing performance of the main control valve should commutate robustness to various interfere factors. Through simulation model built in Simulink/Stateflow and experiment, the effects of relative parameters to reverse performance of main control are analyzed and the main interfere factors for reversing performance are acquired. Treating reverse required time as design objects, some structure parameters as control factors, control pressure, input flow and gaps between spool and valve body as interfere factors, the robust design of the main control valve is done. The combination of factors with the strongest anti-jamming capability is acquired which ensured the reliability and anti-jamming capability of the main control valve. It also provides guidance on design and application of the main control valve used in large flow control with interferes.