• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.563-568
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• 2007

A separate triangular bar type differential pressure flow meter was developed for measuring exhaust gas flow rate from Diesel engine. Three kinds of the separate triangular bar flow meters whose aerodynamic angles are different one another are made and evaluated, respectively. The experimental results show that an aerodynamic shape has a effect on the pressure difference between upstream and downstream at the flow meter, that is, the thinner the shape of the separate triangular bar flow meter is, the smaller the pressure difference at the flow meter is. The separate triangular bar type flow meter was calibrated at both cold and high temperature of the gas flow. A burner system was designed for raising the gas temperature and it was well operated in controlling the gas temperature. An empirical correlation between mass flow rate and differential pressure at the separate triangular bar flow meter was obtained and the empirical correlation was also corrected by the gas temperature.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1680-1686
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• 2009

Flow characteristics of a differential pressure flow meters which have a shape of triangular separate bar (TSB) was investigated according to machining conditions in pressure tapping holes. Size of pressure tapping holes is machined with either 1.0 mm or 1.5 mm in diameter. Also, number of pressure tapping holes are drilled either 9 or 17. The mass flow rate of the TSB flow meters are calibrated with a laminar flow meter by connecting them in line. The mass flow rate in the TSB flow meters are plotted with a non-dimensional parameter H which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters, and atmospheric pressure. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter H was obtained. The empirical correlation showed highly linear relationship between the mass flow rate and the non-dimensional parameter H. The hole size of the pressure tapping holes has a bigger effect on the flow rate than the number of the tapping holes.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.2
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• pp.204-210
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• 2010

The inner structure of the triangular separate bar (TSB) was improved to enhance the productivity of the TSB flow meter by simplifying the machining process for making the flow meter. The cross section of upstream and downstream pressure chamber in the TSB was changed from triangle to circle, which make it possible to substitute the wire cutting by drilling in the process of machining the pressure chamber. The flow rate characteristics of the flow meters was calibrated with a laminar flow meter. Six kinds of flow meters whose diameters of pressure tap for measuring pressure of both upsteam and downstream pressure chamber were different one another were made. The effects of the pressure tap diameter on the flow rate characteristics of the TSB flow meter was little. The mass flow rate characteristics of the flow meters with increasing a non-dimensional parameter which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters and atmospheric pressure shows nearly linear relationship with a correlation coefficient of R=0.998.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.89-94
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• 2008

Differential pressure flow meters which have a shape of triangular separate bar(TSB) were tested for investigating the flow rate characteristics of the flow meters with varying the temperature of the gas flow. Three kinds of the triangular separate bar flow meters whose aerodynamic angles are different one another are used. The mass flow rate of the flow meters are evaluated using a non-dimensional parameter which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters, and atmospheric pressure. A burner system which is similar to gas turbine was used for raising the gas flow temperature. The burner system was operated with varying the air/fuel ratio by controlling both the fuel injection rate from the fuel nozzle and air flow rate from a blower. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter was obtained. The empirical correlation showed linear relationship between the mass flow rate and the non-dimensional parameter H. Also, the mass flow rate characteristics at the TSB flow meter was affected by the gas temperature.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.47.2-47.2
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• 2005

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.351-356
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• 1998

화학 추적자 방법에 의한 정밀 유량 측정기술을 개발하여, 원자력 발전소 주급수 계통의 유량 측정에 사용되고 있는 차압식 유량계의 유량검증에 활용함으로서 발전소의 안전성을 유지하면서 동시에 출력을 극대화하는 것을 목표로 추적자 이용 유량 측정법을 개발하였으며 그 정확도와 유효성에 대한 실험적인 검토를 하여왔다 본 논문에서는 월성 1호기 증기발생기 주급수 유량측정에 동 방법을 적용한 결과를 통하여 추적자 방법의 유효성에 대하여 검토하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.4
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• pp.1501-1509
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• 1996

Differential pressure devices such as an orifice and Venturi are widely used in the measurement of flow rate of fluid mainly due to cost effectiveness and easy installation. In the current study, the viscoelastic effect on discharge and loss coefficients of those flow meters were investigated experimentally. Aqueous solutions of Polyacrylamide (200, 500, and 800 ppm) as viscoelastic fluids were used. Discharge coefficient of an orifice for viscoelastic fluids increased significantly up to approximately 15-20% when compared with that for water, while loss coefficient decreased up to 10-25% depending on the diameter ratio, .betha.. Also, pressure recovery for viscoelastic fluids was extended much longer than that for water. On the other hand, discharge and loss coefficients of Venturi for viscoelastic fluids were found to be strongly dependent on the Reynolds number. In both flow meters, the concentration effect for discharge and loss coefficients was not observed at more over than 200 ppm of aqueous solution. Conclusively, orifice and Venturi flow meters should be calibrated very carefully in the flow rate measurement for viscoelastic fluids.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.214-214
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• 2007

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.449-455
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• 2012

During the measurement of the flow rate of gases such as natural gas, flow hunting is observed in most orifice meters but the intensity of flow hunting at each metering system shows different characteristics. In order to investigate why such a difference occurs and whether the difference actually influences metering error, pipeline network analysis on the main factors and characteristics of flow hunting was carried out in a previous study. Following this, in this study, computational fluid dynamics (CFD) analysis was carried out to clarify the relation between flow instability and flow hunting and determine the factors influencing the orifice meter depending on the intensity of upward pressure fluctuation, time interval, and flow rate. Finally, we showed that the pressure hunting rate is a function of the ratio of the pressure difference before and after an orifice meter. On the basis of CFD analysis results, we also presented some major factors and relations influencing flow hunting.

• Journal of the Korean Institute of Gas
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• v.15 no.1
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• pp.54-59
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• 2011

Generally, the flow hunting is observed in almost all of the orifice meters but the intensity of the flow hunting is different at each metering system. In order to investigate the relations between pipe diameter and the flow instability or the flow hunting in a real metering system, a one-dimensional pipeline network model was built and analyzed for the examination of flow characteristics and relations to the flow hunting, changing diameters of the meter and the pipes before and after the meter. Finally, the effects of pressuredifference variation and flow hunting following to the variations of the diameters of the meter and the pipes before and after the meter were investigated and the relations were examined as well.