Multi-Path Gas Ultrasonic Flow Meter Performance at Low Velocity

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.

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.


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%.


Author(s):  
Yutaka Asako

The energy equation for incompressible flow with the viscous dissipation term is often used for the governing equations of gas flow with low velocity in micro-channels. However, the results which are obtained by solving these equations do not satisfy the first law of the thermodynamics. In the case of ideal gas with low velocity, the inlet and the outlet temperatures of an adiabatic channel are the same based on the first law of the thermodynamics. However, the outlet temperature which is obtained by solving the energy equation for incompressible flow with the viscous dissipation term is higher than the inlet gas temperature, since the viscous dissipation term takes positive value. This inconsistency arose from wrong choice of the relation between the enthalpy and temperature that resulted in neglecting the substantial derivative of pressure term in the energy equation. In this paper the correct energy equation which includes the substantial derivative of pressure term is proposed. Some samples of physically consistent results which are obtained by solving the proposed energy equation are demonstrated.


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):  
Charles W. Morrow

The Liquefied Natural Gas (LNG) chain of processes consumes the equivalent of 10% of initial natural gas flow for liquefaction, transportation and regasification of the natural gas. It is possible with the right process to recover some of this lost investment during the regasification process. The High Temperature Gas Cooled Reactor (HTGR) nuclear power plant appears to possess the characteristics needed to accomplish this recovery. This synergy of processes and fluid properties between an LNG regasification plant and an HTGR provides an opportunity to enhance an already efficient nuclear power generation scheme. Boiling LNG (112 K) provides an ideal cold side heat sink for the helium based Brayton cycle of the HTGR. Helium remains in the gas phase at these low temperatures. The resulting large temperature difference (1000 K) between the high temperature and low temperature sides of a thermal cycle means Carnot efficiencies approach 90%. Achievable efficiencies approach 77%, an increase from 48% for current ambient temperature cooled HTGR designs. Thus a LNG/HTGR plant can deliver half again more power for similar capital investments and operating costs. In addition, boiling LNG with helium saves fuel gas costs for the regasification plant. This paper will show that this combination is feasible and economic. Since both processes are designed to run at maximum capacity, duty cycles and plant availability criteria match. For coastal locations, both processes possess similar site selection criteria. Finally, combining the processes will impose no unmanageable safety constraints on either system and in fact could make safe operation easier to attain. This paper will provide general overviews of an HTGR power plant and of the LNG-to-market sequence, concentrating on regasification plants. The paper will then describe a process that combines an HTGR power plant with an LNG regasification facility to the advantage of both. At full load, the economic benefit for a dual installation supporting what would be a 1.1 GWe power plant before improvement would be approximately $423 million per year.


Author(s):  
Zongshan Wang ◽  
Lin Duanmu ◽  
Junliang Zhu ◽  
Yang Zhao

Chinese Kang with two thousand years’ history is a typical heating method using biomass in cold rural areas. It contributes to reducing the demands of coal and to optimizing the energy consumption structure, but its development is limited for low energy efficiency, poor indoor environment and etc. Therefore, we had a study based on experiment on a new reformed hot-wall Kang. The experimental results show that: the hot-wall Kang improved indoor thermal environment to a great extent. The radiation was the main way of heat elimination through the Kang’s surface, and took up about 65% of the total heat supply. The total heat carried by gas was gained by Kang body and chimney, 64.6% and 9.1% respectivley, and the remaining 26.3% was lost by discharged gas. Under the operation simulating residents’ living habit, the heating efficiency of Kang was up to 80.5% in the period of one testing day. The heat loss transferred to the ground through Kang cave and Hot-wall combustion space was 3.17% and 8.27% respectely. It also showed that the dust-ash layer filled in the cave weakened the ground heat loss and had same effect as that of insulation. Other discoveries: the mass flow rate of flue gas during the burning periods varied in the range of 0.04∼0.08 kg/s. It was turbulent flow at a low velocity, companied with two gas temperature layers. Based on the experiment, the thermal and operation character of hot-wall Kang were made clear. Furthermore, a guide for further optimization of the structure was put forward. And the results also supplied some proofs for the study of gas flow and heat transfer with natural ventilation.


Author(s):  
Claudio Veloso Barreto ◽  
Luis F. G. Pires ◽  
Renata C. Sarmento

The demand of natural gas in the Brazilian energy market is increasing very fast over the few years and it was necessary to enhance the operational performance and safety of the gas distribution. The perfect operation of the natural gas citygate stations is essential to guarantee the delivery of natural gas for the end users like local distribution companies, thermoelectric power plants and large industrial customers within the contracted marketing conditions. These stations receive natural gas directly from high pressure pipelines and reduce the pressure using regulation valves that provoke a temperature reduction due the Joule-Thompson (JT) behavior, typical of natural gases. This temperature loss is compensated by forcing part of the gas flow through water/glycol bath heaters that use natural gas as fuel in the heating process. Usually the downstream gas temperature condition is controlled above a minimal set point while modifying the three-way valve position that regulates hot and cold streams flows. A numerical tool has been developed to simulate the dynamic process inside the natural gas citygate station, and proved to be a reliable tool to analyze the transient performance of the main equipments (filter, three way valve, heater, JT valve, relief valves) when submitted to abnormal conditions or changes in capacity. The methodology developed is able to handle a variety of citygate design.


2019 ◽  
Vol 297 ◽  
pp. 03001
Author(s):  
Sergey Azikhanov ◽  
Aleksandr Bogomolov ◽  
Georgiy Dubov ◽  
Sergey Nokhrin

The prospects for the use of natural gas as a motor fuel are considered. The state-run program for the development of natural-gas-fuelled vehicles will entail an increase in the share of transport operating on natural gas. The data on the thermal performance of natural gas from various fields, the volumetric heat values of the stoichiometric mixture of which is almost the same, are given. The analysis of the operation of gas-diesel-fuelled BelAZ dump truck, which burns liquefied natural gas, is conducted. The schematic diagram for engine power supply with liquefied natural gas is given. The calculation of the liquefied natural gas supply system with the replacement of diesel fuel by 33% was made. As a result of the calculation, the diameter of a fuel manifold after injectors, which provides the recommended gas velocity through a manifold, was determined. The instrumentation system for controlling the amount of supplied natural gas is proposed. The complex allows obtaining data on the instantaneous gas flow rate and the total flow rate over a period of time. A pulsation damper used as part of the system allowed reducing gas pulsation in fuel manifolds after injectors, to create conditions for the use of orifice plate flow meters, and ensured the uniform supply of natural gas to both banks of cylinders, which favourably affected the engine.


Author(s):  
B.S. Soroka ◽  
V.V. Horupa

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.


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