scholarly journals Calculations of the Flow of Natural Gas Through Critical Flow Nozzles

1970 ◽  
Vol 92 (3) ◽  
pp. 580-586 ◽  
Author(s):  
R. C. Johnson
Keyword(s):  
Natural Gas ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Range ◽  
Gas Mixtures ◽  
Empirical Method ◽  
Critical Flow ◽  
One Dimensional ◽  
Rate Calculation

The mass flow rate of methane and 19 natural gas mixtures through critical flow nozzles has been calculated. The calculation assumes the flow to be one-dimensional and isentropic. The pressure range is 0 to 1000 psi and the temperature range is from 450 to 700 deg Rankine. From a study of the results, a simple empirical method for making this mass flow rate calculation is proposed. This method would apply to natural gas mixtures whose composition is known and whose components have no more than four carbon atoms.

On the Dynamics of Compressor Surge

1976 ◽  
Vol 18 (5) ◽  
pp. 234-238 ◽  
Author(s):  
D. H. McQueen
Keyword(s):  
Mass Flow Rate ◽  
Limit Cycle ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Head ◽  
Centrifugal Compressors ◽  
One Dimensional ◽  
Acoustical Properties ◽  
Compressor Surge ◽  
The One

The one-dimensional equations of surge in centrifugal compressors are solved graphically for the pressure head and mass flow rate as functions of time for a variety of situations, and the results are discussed in terms of the acoustical properties of the external piping. Two important parameters affecting the nature of the surge limit cycle are found to be simply related to the acoustic capacitance and acoustic inductance of the system.

Air mass balance for mass flow rate calculation in pneumatic conveying

2010 ◽  
Vol 202 (1-3) ◽  
pp. 62-70 ◽  
Author(s):  
Cecilia Arakaki ◽  
Ali Ghaderi ◽  
Arild Sæther ◽  
Chandana Ratnayake ◽  
Gisle G. Enstad
Keyword(s):  
Mass Balance ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pneumatic Conveying ◽  
Air Mass ◽  
Rate Calculation

Uncertainty Evaluation of the Natural Gas Molar Mass and Its Flow Rate Impact

2008 ◽  
Author(s):  
Elcio Cruz de Oliveira
Keyword(s):  
Natural Gas ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Molar Mass ◽  
Internal Diameter ◽  
Gas Measurement ◽  
Oil And Natural Gas ◽  
Mass Uncertainty ◽  
The Impact

In Brazil, the National Oil Agency — ANP and the National Metrology Institute elaborated Regulation No 1, on June 19th 2000. This government decree approves the Regulation of the Measurement Technique of Oil and Natural Gas, which establishes the minimum conditions and requirements for the oil and natural gas measurement systems, in order to guarantee accurate and complete results. The natural gas measurement fiscal systems must be projected, calibrated and operated so that the measurement uncertainty does not exceed 1.5%. Based on the norms AGA and ISO, the mathematical model for the calculation of the mass flow rate, depends on quantities that have well known uncertainty such as: orifice plate diameter, pipeline internal diameter, compressibility factor, discharge coefficient, differential pressure, static pressure and flow temperature. However, for the molar mass standard uncertainty fixed values are utilized in Brazil (mainly by IPT and PUC-RJ), around 0.30%, independent of the natural gas composition. The objective of this work is to develop a methodology to calculate the molar mass uncertainty of the natural gas derived from its chemical composition, analyzed by gaseous chromatography and to comparing it with the value currently practiced, evaluating the impact proceeding from this difference in the mass flow rate of the natural gas. Based on this methodology, the molar mass uncertainty is around 0.05% and the fiscal system uncertainty decreases in more than 10% when it is compared with the mass molar fixed value uncertainty.

CFD Simulation of Gas Distributor with Two Chambers

2014 ◽  
Vol 989-994 ◽  
pp. 2264-2267
Author(s):  
Dong Fang Zhao ◽  
Feng Guo Liu
Keyword(s):  
Natural Gas ◽  
Mass Flow Rate ◽  
Turbulence Model ◽  
Mass Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Second Order ◽  
Gas Distributor ◽  
New Type ◽  
Simulation Results

This paper investigated a new type of gas distributor with two chambers by CFD software. The distributor has a natural gas inlet and nine nozzle outlets. For the investigation of this project, the mass flow rate of the distributor was analyzed in this paper to provide a way to optimize the structure of distributor. The N-S equations approached with the RNG k-ε turbulence model and the discretization were employed second order upwind. The simulation results will provide a number of useful suggestions and references for the further design.

Research on the Smoke Mass Flow Rate in One-Dimensional Spreading Stage in Tunnel with Multiple Fire Sources

2021 ◽  
Author(s):  
Linjie Li ◽  
Du Fang ◽  
Yang Yingying ◽  
Wei Liangwen ◽  
Feng Huang ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
One Dimensional

Predictions of Two-Phase Critical-Flow Boundary and Mass-Flow Rate Across Chokes

2009 ◽  
Vol 24 (02) ◽  
pp. 249-256 ◽  
Author(s):  
Eissa M. Alsafran ◽  
Mohan G. Kelkar
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Critical Flow ◽  
Two Phase ◽  
Flow Boundary

scholarly journals Modelling of a Single Passage Air PV/T Solar Collector: Experimental and Simulation Design

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 763
Author(s):  
Noran Nur Wahida Khalili ◽  
Mahmod Othman ◽  
Mohd Nazari Abu Bakar ◽  
Lazim Abdullah
Keyword(s):  
Error Analysis ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Solar Collector ◽  
Total Efficiency ◽  
Research Attention ◽  
Air Mass ◽  
One Dimensional ◽  
Simulation Results

The hybrid photovoltaic/thermal solar collector has attracted research attention for more than five decades. Its capability to produce thermal energy simultaneously with electrical energy is considered attractive since it provides higher total efficiency than stand-alone photovoltaic or thermal systems separately. This paper describes theoretical and experimental studies of a finned single pass air-type photovoltaic/thermal (PV/T) solar collector. The performance of the system is calculated based on one dimensional (1D) steady-state analysis using one dimensional energy balance equations, where simulation was carried out using MATLAB. Experiments were carried out to observe the performance of the solar collector under changes in air mass flow rate. Experimental values on photovoltaic panel temperature and air temperature on both air inlet and outlet, together with the ambient temperature and solar radiation were measured. The simulation results were validated against the results obtained from experiments using the error analysis method, Root Mean Square Error. At a solar irradiance level of 800 to 900 W/m2, the thermal efficiency increases to 20.32% while the electrical efficiency increases to 12.01% when the air mass flow rate increases from 0.00015 kg/s to 0.01 kg/s. The error analysis shows that both experimental and simulation results are in good agreement.

Metering of Steam-Water Two-Phase Flow by Sharp-Edged Orifices

1965 ◽  
Vol 180 (1) ◽  
pp. 549-572 ◽  
Author(s):  
Russell James
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Critical Flow ◽  
Water Mixture ◽  
Two Phase ◽  
In Series ◽  
Trial And Error Method ◽  
Error Method ◽  
Stagnation Enthalpy

This paper describes work conducted on the passage of steam-water mixtures through standard sharp-edged orifices for the prediction of flow conditions. When the stagnation enthalpy or alternatively the dryness fraction at the orifice is known, it is shown that the mass flow rate can be approximately determined. For the case where a steam-water mixture passes through a pipeline to the atmosphere or to a low-pressure receiver so that critical flow occurs at the outlet, both the mass flow rate and the stagnation enthalpy may be approximately evaluated using an orifice meter in series with a pressure tapping located at the point of critical flow. In this case, a trial-and-error method is necessary. The experimental results were within a range of dryness fractions from 1 per cent to 56 per cent, orifice pressures from 75 to 275 lb/in2 abs., differentials from 15 to 780 mmHg under water and flow rates from 54 700 to 508 000 lb/h. Orifices of 5.591 and 6.615 in diameter were installed in 7.9-in diameter pipes which were equipped with radius ( D and D/2) taps. The method employs a correlation between the homogeneous dryness fraction x, and a corrected dryness fraction x m necessary for evaluating the two-phase density used in the conventional single-phase meter equation.

A One-Dimensional Analytical Method for Turbine Blade Preliminary Cooling Design

2016 ◽  
Author(s):  
Chen Li ◽  
Jian-jun Liu
Keyword(s):  
Mass Flow Rate ◽  
Turbine Blade ◽  
Mass Flow ◽  
Flow Rate ◽  
Film Cooling ◽  
Three Dimensional ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
One Dimensional ◽  
Cooling Design

The turbine blade cooling design is a complex procedure including one-dimensional preliminary cooling design, detailed two-dimensional design and fluid network analyses, and three-dimensional conjugate heat transfer and FEM predictions. Frequent alteration and modification of the cooling configurations make it unpractical to obtain all of three-dimensional design results quickly. Preliminary cooling design deals mainly with the coolant requirements and can be knitted into fluid network to look up the expected cooling structural style to promote three-dimensional geometry design. Previous methods to estimate the coolant requirements of the whole turbine blade in the preliminary cooling design were usually based on the semi-empirical air-cooled blade data. This paper combines turbine blade internal and external cooling, and presents a one-dimensional theoretical analytical method to investigate blade cooling performance, assuming that the coolant temperature increases along the blade span. Firstly, a function of non-dimensional cooling mass flow rate is derived to describe the new relationship between adiabatic film cooling effectiveness and overall cooling effectiveness. Secondly, a new variable related to film cooling is found to estimate the required adiabatic film cooling effectiveness without using the empirical correlations. Finally, a theoretical calculation about the relationship between non-dimensional cooling mass flow rate and overall cooling effectiveness well corresponds to semi-empirical air-cooled blade data within regular range of cooling efficiency. The currently proposed method is also a useful tool for the blade thermal analysis and the sensitivity analysis of coolant requirements to various design parameters. It not only can provide all the possible options at the given gas and coolant inlet temperatures to meet the design requirement, but also can give the third boundary conditions for calculating the blade temperature field. It’s convenient to use the heat transfer characteristic of internal cooling structures to estimate the coolant mass flow rate and the channel hydraulic diameter for both convection cooling and film cooling.

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