• Journal of Korean Society of Water and Wastewater
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• v.18 no.4
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• pp.418-424
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• 2004

An abrupt high pollution loads in combined sewer systems is believed to be caused by first flushing actions and the resuspension of sediments deposited in sewers. Therefore, pollution loads in each flow regulator have a different tendency. This systems control intercepting flow in each flow regulator using water quality and water level. A desired quantity of intercepting flow was adjusted and the necessary slide position for a constant intercepting is calculated by Optimization programming. This systems make it possible to reduce pollution loads caused by CSOs to water body, may be alternative for the stable operation of STP through improving water quality to STP.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.99-104
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• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2535-2542
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• 2000

The regulator system has been modeled and combined to a swashplate type axial piston pump. Linear approximation has been performed for nonlinear coefficient terms of an axial piston pump-regulator model without significantly affecting accuracy. Based on the mathematical model of an axial piston pump-regulator system, a couple of characteristic curves of negative flow control and horsepower control are drawn, which show a good correlation with those of experimental results. So the simplified axial piston pump-regulator model in this paper is expected to be utilized not only for the design and analysis of hydraulic circuit of excavator but also for prevention of engine overload.

• Journal of the Korean Institute of Gas
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• v.25 no.5
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• pp.37-51
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• 2021

The pressure drop phenomenon that occurs when the same flow rate is supplied to the gas regulator was analyzed. The regulator moves the position of the piston through the interaction of the force acting on the upper and lower parts of the piston and the spring tension to release the pressure of a specific range in a specific environment as constant pressure, thereby maintaining the pressure. The flow characteristics and pressure control process of the regulator were investigated through a numerical analysis technique as the volume of the fluid inside the regulator changed. As the gap between the piston and the piston seat decreased, the pressure drop increased and the flow velocity increased. It was verified through numerical analysis that the piston was positioned at 0.12mm under the same conditions as the pressure-flow test (inlet pressure 3MPa, outlet pressure 0.8MPa, flow rate 70kg/h).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.377-378
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• 2007

• The KSFM Journal of Fluid Machinery
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• v.10 no.1 s.40
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• pp.49-55
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• 2007

An 'Y' strainer type automatic flow rate regulating valve, which functions are to remove impurities from hot water inside the pipe and to maintain a constant flow rate regardless of variations of the differential pressure between valve inlet and outlet at the same time, is developed for distributing hot water equally to several pipes with district heating or central heating system. Numerical analysis of the three dimensional turbulent flow field in a valve shape is carried out to confirm the flow field whether the designed regulator shape is acceptable or not. The final developed valve improves installation time and cost and maintenance ability comparing with set-up 'Y' strainer and regulator separately. Tolerance for the nominal flow rate is also satisfied within ${\pm}5%$.

• Journal of Biomedical Engineering Research
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• v.36 no.6
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• pp.264-270
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• 2015

A mock circulatory loop system has been developed to construct a simulator for trainees in cardiopulmonary bypass systems or to simulate a test environment for cardiac-assist devices. This paper proposes a computerized mock circulatory loop system whose node is modularized by using a servo control flow regulator to simulate dynamic change of the hemodynamic status. To observe the effect of time-varying resistance, one with hemodynamic properties, the proposed system replicates the planned cross-sectional areas of the outlet of a ventricular assist device in terms of voltage input of a servo valve. The experiment is performed (1) for steady-input commands of selected area sizes and (2) for dynamic commands such as monotonous increase and decrease, and oscillatory functions of the voltage input, and a computer program based on LabVIEW (National Instruments, Austin, USA) processes every measured data and control command to the servo valve. The results show that the pressure and flow at the target points with respect to time-varying resistance match intuitive estimation: the pressure at the outlet and the pressure drop between both sides of the valve increased and the flow at the outlet decreased for increased resistance.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.188-191
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• 2007

This paper shows the Development of In-tank pressure regulator and Solenoid Valve used in FCV(Fuel Cell Vehicle). We have developed new type of Regulator and Solenoid through analysis of the structure and characteristics of component of FCS(Fuel Cell System) from the advanced technology. Now it is possible to localize the component by making use of the development of Regulator and Solenoid made by us. Regulator and Solenoid is a equipment to control hydrogen pressure supplied into a stack. Therefore, outlet pressure, a flow of fluid and temperature are important parameters according to a inlet pressure. And leak test, endurance test and burst test should be done to guarantee the performance and safety of Regulator and Solenoid used in the fuel of high pressure. Also, Hydrogen friendly materials are applied to inner parts of the Regulator, Solenoid and weight reduction is done to cost saving in part not related to performance. As a result, we have proven the good performance and reliability in endurance of Regulator, Solenoid and will make an development in performance as well as durability to ensure industrialization.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.2
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• pp.129-132
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• 2011

This paper presents small hydrogen regulator for the mobile fuel cell. Mobile fuel cell is generally classified into open-end type and dead-end type. In the open-end type, flow rate of hydrogen is constantly controlled, while pressure of hydrogen is constantly maintained in the dead-end type. Considering the efficiency and stability of the fuel usage, dead-end type is more suitable with mobile fuel cell. Mobile fuel cell operated by dead-end mode requires hydrogen regulator which controls the hydrogen pressure from 0.1bar to 0.5bar within 3% error. In this paper, small hydrogen regulator (volume of 2.6cc) was fabricated by stainless steel. Regulation characteristics was experimentally evaluated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.347-352
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• 2009

Pneumatic system is widely applied to ground facility and launcher on-board system. The main requirements of pneumatic system is to meet pressure and flow requirements of gas consumers. For launcher related applications, different from other applications, very high flow is required which can leads to supply pressure drop against required setting pressure. The supply pressure decrease is closely related to regulator characteristics. In this paper, the characteristics of pneumatic regulator related to supply pressure decrease and the control methods for reducing the pressure offset are reviewed.