• The KSFM Journal of Fluid Machinery
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• v.20 no.2
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• pp.47-52
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• 2017

In general industry, TFM(turbine flow meters) as measuring instruments having high reliability are widely used in the trade of petroleum and in the measurement of tap water and hot water. The TFM is performed calibration for using in the field and is mainly calibrated at room temperature. Since accuracy of TFM depends on Reynolds number of fluid, TFM is calibrated at same Reynolds number by changing flow rate. Furthermore, the TFM using a fluid of high temperature should have considered for other factors such as the thermal expansion of the parts and characteristics change is unknown changes in the turbine flow meter accordingly. In this paper, two turbine flowmeter are experimentally studied about characteristics change using the facilities which can change fluid temperature from 6 degree celsius to 90 degree celsius. As a result, the turbine flow meter can be calibrated to minimize the error characteristic at a similar temperature and the actual temperature.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.861-868
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• 2011

Flowmeters that measure the amount of fluid passing through conduits must kept accurate by comparison and the periodic calibration. The reference meters used are clamp-on meters that mount sensors on the outer wall of the pipe. They are called 1-path, 2-path or 4-path flowmeters depending on the number of sensors. We selected a flowmeter mainly used for K-water as test a flowmeter. We carried out experiments to find the intrinsic error of the flowmeter and errors in the downstream of a double bent pipe. The results show that there are the sensor locations that meet the tolerance. We suggested the angle of the sensor, the straight run from the downstream of the bent pipe and the number of sensors. So it is possible to improve the water treatment process and increase the accounted water rate by upgraded flow measurement technology.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.684-691
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• 2022

Hydrogen fuel cell electric vehicles are typically refueled at a wide range of temperatures (-40℃ to 85℃) in the hydrogen refueling station in accordance with the worldwide accepted standard. Currently, there is no traceable method by which to verify and calibrate the hydrogen flowmeters to be used at hydrogen refueling stations except for a water calibration process as a conventional method. KRISS hydrogen field test standard based on the gravimetric principle was developed to verify the measurement accuracy of the mass flowmeter to be used at hydrogen refueling stations for the first time in Korea.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.109-122
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• 2018

Domestic LPG meters are being tested for LPG quantification in accordance with the "Measures Act". The LPG meter is re-tested every three years in accordance with the "Enforcement Decree of the Measures Act". The maximum permissible error within the test is within ${\pm}1.0%$, and the tolerance is within ${\pm}1.5%$. For the quantitative measurement of LPG, a hydrometer for LPG, a balance, and a pressure vessel are used. The volume of LPG varies in depending on the temperature and pressure. The current quantitative measurement method of LPG requires the measurement of temperature, pressure and density in order to determine the volume of LPG, respectively, and some equipments are needed accordingly. Coriolis mass flowmeter, on the other hand, measure the mass flow, density and temperature at the same time, and can be converted and calculated to the required values using a computer program, also it is widely applied in the industrial field. In this study, the volume of LPG was measured using a Coriolis mass flowmeter as a basic study of LPG quantitative measurement. In addition, it is shown that it is possible to apply for the LPG quantitative measurement using the Coriolis mass flowmeter by comparing it with the conventional LPG quantitative measurement method.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.228-239
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• 2013

Purpose: The objectives of this study were to develop an automated disinfectant dilution system, and an automated data management system for spraying amount for resolving uncertainty problem. Methods: Proper diluting rate was made by a controlled volume pump for liquid disinfectant and a screw conveyer pump for solid disinfectant. The water capacity of disinfecting system of 400 L was controlled by two water level sensors. The water quantity of water tank was controlled by the signals which were produced by the water level sensors. Signals were processed by Labview Programming, and ON/OFF of solenoid valve that was used for controlling water supplying to water tank, was controlled by SSR. The operating time of pumps for disinfectant was controlled quantitatively. A turbine flowmeter was used for development of automated measurement system for spraying amount of disinfectant. In order to save the flowmeter data and to control the spraying system, a multi-function data logger was used, and it was processed and saved in Excel file by a program developed in this study. Results: Labview 2010 was used for programming to control the automated measurement system for spraying amount of disinfectant. Results showed that the relationship between flowmeter value and time had a significant linear relationship such as 0.99 of $R^2$. Generally, 6.74 L/s of diluted disinfectant is sprayed for a vehicle passing through the disinfection system (about 15 seconds). Test results showed that average error between the measured spraying amount and the flowmeter data was 50 mL, and the range of error was 1.3%. Since the amount and time of spraying could be saved in real-time by using the spreadsheet files which could not be modified arbitrarily, it made possible to judge objectively whether the disinfection spraying was performed or not. Test results of spraying liquid and solid disinfectant showed that the errors between the measured discharge rate and the theoretical one were ranged within 3-4% for various dilution rates. Conclusions: The disinfection system developed would be working accurately. The automated spraying data base management system satisfied the purpose of this study. The automated dilution process system developed in this study could discharge liquid and solid disinfectant with accurate dilution rate, relatively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.9
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• pp.613-620
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• 2016

In order to scrutinize the fluid conductivity effects on the electromagnetic flowmeter(EMF) characteristics, a small scale EMF was designed and fabricated. The measuring tube has a $3mm{\times}4mm$ rectangular cross-section, 9 mm length, and a $2mm{\times}3mm$ plate electrode and a ${\Phi}1.5mm$ point electrode. The design parameters, such as the magnetizing frequency and the number of coil turns, and the diameter were optimized. The EMF was tested with a gravimetric calibrator and showed good linearity in the range of 0 to $1.17{\times}10^{-5}m^3/s$. The fluid conductivity was varied between 3 and $11{\mu}S/cm$, and the magnitude of the flow signal was proportional to the fluid conductivity and the wetted area of the electrode. The design information and the test results provide flow measurement techniques for very low flowrate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.3
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• pp.289-295
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• 2004

The heat transfer coefficient and pressure drop during gas cooling process of carbon dioxide in a horizontal tube were investigated. The experiments were conducted without oil in the refrigerant loop. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flowmeter, an evaporator, and a gas cooler(test section). The main components of the water loop consist of a variable-speed pump, an isothermal tank, and a flowmeter. The gas cooler is a counterflow heat exchanger with refrigerant flowing in the inner tube and water flowing in the annulus. The test section consists of smooth, horizontal stainless steel tube of the outer diameter of 9.53mm and of the inner diameter of 7.75mm. The length of the test section is 6m. The refrigerant mass fluxes were 200∼300kg/(m2$.$s) and the inlet pressure of the gas cooler varied from 7.5㎫ to 8.5㎫. The main results were summarized as follows : Pressure drop of CO2 increases with increasing gas cooler pressure. The friction factors of CO2 in a horizontal tube show a relatively good agreement with the correlation by Blasius. The heat transfer coefficient of CO2 in transcritical region increases with decreasing gas cooler pressure and decreasing mass flux of CO2. Most of correlations proposed in a transcritical region showed significant deviations with experimental data except for those predicted by Gnielinski.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.2
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• pp.180-186
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• 2001

The condensation heat transfer coefficients of pure refrigerants R-22, R-134a, and a binary refrigerant mixture R-410A flowing in a small diameter tube were investigated. The experiment apparatus consists of a refrigerant loop and a water loop. The main components of the refrigerant loop consist of a variable-speed pump, a mass flowmeter, an evaporator, and a condenser(test section). The water loop consists of a variable-speed pump, an isothermal tank, and a flowmeter. The condenser is a counterflow heat exchanger with refrigerant flowing in the inner tube and water flowing in the annulus. The test section consists of smooth, horizontal copper tube of 3.38mm outer diameter and 1.77mm inner diameter. The length of test section is 1220mm. The refrigerant mass fluxes varied from 450 to 1050kg/(㎡$.$s) and the average inlet and outlet qualities were 0.05 and 0.95, respectively. The main results were summarized as follows ; in the case of single-phase flow, the heat transfer coefficients increase with increasing mass flux. The heat transfer coefficient of R-410A was higher than that of R-22 and R-134a, and the heat transfer for small diameter tubes were about 20% to 27% higher than those predicted by Gnielinski. In the case of two-phase flow, the heat transfer coefficients also increase with increasing mass flux and quality. The condensation heat transfer coefficient of R-410A was slightly higher than that of R-22 and R-134a. Most of correlations proposed in the large diameter tube showed significant deviations with experimental data except for the ranges of low quality and low mass flux.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.1
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• pp.65-74
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• 2004

The heat transfer coefficient and pressure drop of $CO_2$(R-744) during gas cooling Process of carbon dioxide in a horizontal tube were investigated experimentally and theoretically. The experiments were conducted without oil in the refrigerant loop. The main components of the refrigerant loop consist of a receiver. a variable-speed pump. a mass flowmeter, an evaporator. and a gas cooler(test section). The main components of the water loop consist of a variable-speed Pump. an constant temperature bath. and a flowmeter. The gas cooler is a counterflow heat exchanger with refrigerant flowing in the inner tube and water flowing in the annulus The test section consists of smooth, horizontal stainless steel tube of 9.53 mm outer diameter and 7.75 mm inner diameter. The length of test section is 6 m. The refrigerant mass fluxes were 200 ~ 300 kg/($m^2{\cdot}s$) and the inlet pressure of the gas cooler varied from 7.5 MPa to 8.5 MPa. The main results were summarized as follows : The predicted correlation can evaluated the R-744 exit temperature from the gas cooler within ${\pm}10%$ for most of the experimental data, given only the inlet conditions. The predicted gas cooley capacity using log mean temperature difference showed relatively food agreement with gas cooler capacity within ${\pm}5%$. The pressure drop predicted by Blasius estimated the pressure drop on the $CO_2$ side within ${\pm}4.3%$. The predicted heat transfer coefficients using Gnielinski's correlation evaluated the heat transfer coefficients on the $CO_2$ side well within the range of experimental error. The predicted heat transfer coefficients using Gao and Honda's correlation estimated the heat transfer coefficients on the coolant side well within ${\pm}10\;%$. Therefore. The predicted equation's usefulness is demonstrated by analyzing data obtained in experiments.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.132-137
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• 2005

This research presents a modeling and a manufacturing method of screw type flow meter. This paper introduces the efficient design and manufacturing method of screw type flow meter using reverse engineering and test technology. The methods introduced this paper utilize the reverse engineering that is increasing accuracy of modeling and manufacturing of reverse model. And then it can be used in performance test with hydraulic test equipment. Hence this can be used in the basic document for development of the quite accurate flow meter.