Gravimetric Calibration of Critical Flow Venturi Nozzles

Volume 1 ◽  
2004 ◽  
Author(s):  
Thomas B. Morrow

The Metering Research Facility (MRF) was commissioned in 1995/1996 at Southwest Research Institute for research on, and calibration of natural gas flow meters. A key commissioning activity was the calibration of critical flow Venturi (sonic) nozzles by a gravimetric proving process flowing nitrogen or natural gas at different pressures. This paper concerns the calibration of the four sonic nozzles installed in the MRF Low Pressure Loop (LPL). Recently, a new project prompted a review of the relations used to calculate sonic nozzle discharge coefficient in the LPL data acquisition computer code. New calibrations of the LPL sonic nozzles were performed flowing natural gas over a lower range of pressure than used in the original commissioning tests. The combination of new and old gravimetric calibration data are shown to agree well with correlations published by Arnberg and Ishibashi (2001) and by Ishibashi and Takamoto (2001) for laminar, transitional and turbulent boundary layer flow in critical flow Venturi nozzles.

1989 ◽  
Vol 111 (1) ◽  
pp. 22-33
Author(s):  
V. C. Ting ◽  
J. J. S. Shen

This paper presents the orifice calibration results for nominal 15.24, 10.16, and 5.08-cm (6, 4, 2-in.) orifice meters conducted at the Chevron’s Sand Hills natural gas flow measurement facility in Crane, Texas. Over 200 test runs were collected in a field environment to study the accuracy of the orifice meters. Data were obtained at beta ratios ranging from 0.12 to 0.74 at the nominal conditions of 4576 kPa and 27°C (650 psig and 80°F) with a 0.57 specific gravity processed, pipeline quality natural gas. A bank of critical flow nozzles was used as the flow rate proving device to calibrate the orifice meters. Orifice discharge coefficients were computed with ANSI/API 2530-1985 (AGA3) and ISO 5167/ASME MFC-3M-1984 equations for every set of data points. The uncertainty of the calibration system was analyzed according to The American National Standard (ANSI/ASME MFC-2M-A1983). The 10.16 and 5.08-cm (4 and 2-in.) orifice discharge coefficients agreed with the ANSI and ISO standards within the estimated uncertainty level. However, the 15.24-cm (6-in.) meter deviated up to − 2 percent at a beta ratio of 0.74. With the orifice bore Reynolds numbers ranging from 1 to 9 million, the Sand Hills calibration data bridge the gap between the Ohio State water data at low Reynolds numbers and Chevron’s high Reynolds number test data taken at a larger test facility in Venice, Louisiana. The test results also successfully demonstrated that orifice meters can be accurately proved with critical flow nozzles under realistic field conditions.


2005 ◽  
Author(s):  
Thomas B. Morrow

Multi-path gas ultrasonic flow meters are used to measure the flow rate of natural gas in custody-transfer metering applications. Steady-flow tests were performed in the high-pressure loop (HPL) of the Southwest Research Institute (SwRI) Metering Research Facility (MRF) flowing natural gas through two 300 mm (12-inch) diameter multi-path ultrasonic flow meters with different ultrasonic path configurations. Tests were performed with both small and large temperature differences between the flowing gas temperature and the outdoor ambient temperature. This paper presents the results of the large temperature difference tests with and without an upstream flow conditioner for one multi-path ultrasonic meter in the low-flow range of 0.15 m/s (0.5 ft/s) to 0.30 m/s (1 ft/s). Test conditions were selected to complement a computational fluid dynamics (CFD) study performed by Morrison and Brar [2004,2005] at Texas A&M University. The experimental results confirm that the gas flow in the ultrasonic meter was thermally stratified (as predicted by Morrison and Brar [2004]) and show the effects of thermal stratification on path velocities, meter diagnostic path velocity ratios, and on meter accuracy. The results show that the flow conditioner was relatively ineffective in smoothing the axial velocity profile distortion caused by thermal stratification in this low velocity range.


Author(s):  
J. Adair ◽  
A. Kirkpatrick ◽  
D. B. Olsen ◽  
H. Gitano-Briggs

The topic of this paper is the simulation of the airflow characteristics of a large bore two stroke natural gas fueled engine. The modeling was performed with the program WAVE, a computer code developed for engine cycle simulations. The engine studied was a four cylinder Cooper GMV engine. This engine has an articulated crankshaft connecting even and odd bank cylinders. Due to the articulation, the even bank cylinders have different piston profiles, port profiles, and compression ratios than the odd bank cylinders. Due to the non-symmetric timing and articulated geometry of the odd and even banks, the gas flow processes are not the same for each cylinder bank. The different manifold and port pressure profiles result in different amounts of trapped mass in the odd and even banks. The even bank is predicted to have a smaller amount of trapped mass and slightly lower trapping and scavenging efficiencies. Finally, the model predicts that the even bank cylinders attain higher maximum temperatures, which would produce increased NOx.


2019 ◽  
Vol 141 (6) ◽  
Author(s):  
K. K. Botros ◽  
H. Charette ◽  
M. Martens ◽  
M. Beckel ◽  
G. Szuch

Abstract The thrust loading on a vertical blowdown stack during a natural gas blowdown was investigated using a combined experimental and modeling approach. A gravimetric vessel initially at 4000 kPa-g was blown down through two geometrically different stack assemblies. Thrust loads were measured using a dynamic weigh scale typically used for gravimetric calibration of gas flow meters. A one-dimensional (1D) compressible flow model, calibrated using the experimental data, revealed stagnation pressure losses at the entrance to the riser, resulting in lower thrust loads. A comparison between thrust loading obtained from the measurements and the 1D compressible flow model is presented. This work shows that the analytical flow model predicts the blowdown thrust loads within ±30%.


2014 ◽  
Vol 18 (5) ◽  
pp. 1505-1510 ◽  
Author(s):  
Zhao-Qin Yin ◽  
Dong-Sheng Li ◽  
Jin-Long Meng ◽  
Ming Lou

The purpose of this investigation is to understand flow characteristics in mini/micro sonic nozzles, in order to precisely measure and control miniscule flowrates. Experimental and numerical simulation methods have been used to study critical flow Venturi nozzles. The results show that the nozzle?s size and shape influence gas flow characteristics which leading the boundary layer thickness to change, and then impact on the discharge coefficient. With the diameter of sonic nozzle throat decreasing, the discharge coefficient reduces. The maximum discharge coefficient exits in the condition of the inlet surface radius being double the throat diameter. The longer the diffuser section, the smaller the discharge coefficient becomes. Diffuser angle affects the discharge coefficient slightly.


2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Abdoalmonaim S. M. Alghlam ◽  
Vladimir D. Stevanovic ◽  
Elmukhtar A. Elgazdori ◽  
Milos Banjac

Simulations of natural gas pipeline transients provide an insight into a pipeline capacity to deliver gas to consumers or to accumulate gas from source wells during various abnormal conditions and under variable consumption rates. This information is used for the control of gas pressure and for planning repairs in a timely manner. Therefore, a numerical model and a computer code have been developed for the simulation of natural gas transients in pipelines. The developed approach is validated by simulations of test cases from the open literature. Detailed analyses of both slow and fast gas flow transients are presented. Afterward, the code is applied to the simulation of transients in a long natural gas transmission pipeline. The simulated scenarios cover common operating conditions and abrupt disturbances. The simulations of the abnormal conditions show a significant accumulation capacity and inertia of the gas within the pipeline, which enables gas packing and consumers supply during the day time period. Since the numerical results are obtained under isothermal gas transient conditions, an analytical method for the evaluation of the difference between isothermal and nonisothermal predictions is derived. It is concluded that the nonisothermal transient effects can be neglected in engineering predictions of natural gas packing in long pipelines during several hours. The prescribed isothermal temperature should be a few degrees higher than the soil temperature due to the heat generation by friction on the pipelines wall and heat transfer from the gas to the surrounding soil.


The use of natural gas in several countries, especially in Indonesia is essential. In gas distribution, every industry and household will not be separated from the measurement system that aims to find out how much natural gas has been used. For this reason, the use of a gas flow meter is necessary. There are several types of gas flow meter can be used in measuring the gas volume. Some types of gas flow meters are gas turbine meters, rotary gas meters and diaphragm gas meters. The primary difference of each type of gas flow meter is the pressure capacity and the speed of the gas flow through it. Flow meter gas turbine is one type of gas flow rate measuring device. There are moving parts consisting of a propeller whose rotation speed is proportional to the flow rate through the flow meter. The type of gas turbine meter is Fluxi 2000/TZ. Fluxi 2000/TZ is designed to measure natural gas and various non-corrosive gases. This tool can be used to measure low gas flow and high gas flow. This tool can also be used to measure flow under various pressure conditions. Corus is the name of the type of gas volume converter. Corus is one instrument that supports the reading process of various gas meters, and one of them is a gas turbine meter. Corus is designed to achieve high levels of performance and accuracy from robust electronic equipment so that the results of reading the fluid volume available on the gas turbine meter can be calculated more accurately regard to the amount of temperature, pressure and compressibility. The working principle and characteristics of the two instruments make the measurements more accurate.


Author(s):  
Jeffrey R. Friedman ◽  
David Keyser

Performance Test Codes require primary mass flow accuracies that in many applications require the laboratory-quality calibration of differential pressure meters. It is also true that many performance tests are conducted at Reynolds numbers and flows well above the laboratories’ capacities, and sound extrapolation methods had to be developed. Statistical curve-fits and regression analyses by themselves, absent fluid-dynamic foundations, are not valid procedures for extrapolation. The ASME PTC 19.5-2004 discharge coefficient equations presented in this paper are suitable for use and extrapolation of laboratory calibration data.


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