Transient Simulation of Natural Gas Citygates Stations

2010 ◽  
Author(s):  
Claudio Veloso Barreto ◽  
Luis F. G. Pires ◽  
Renata C. Sarmento
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Gas Flow ◽  
Heating Process ◽  
Gas Temperature ◽  
Minimal Set ◽  
Temperature Loss ◽  
Thermoelectric Power Plants ◽  
Valve Position ◽  
Flow Through

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.

Research and Design of the Control System for Natural Gas Heater

2013 ◽  
Vol 842 ◽  
pp. 541-545
Author(s):  
Yun Guo ◽  
Zhi Qiang Huang ◽  
Shun Xin Yang
Keyword(s):  
Control System ◽  
Natural Gas ◽  
Power Plants ◽  
Production Efficiency ◽  
Combustion Efficiency ◽  
Gas Temperature ◽  
Technical Requirements ◽  
Real Time Measurement ◽  
And Control ◽  
Measurement And Control

Natural gas heaters are widely used in gas-fired power plants to meet the combustion needs and to improve the combustion efficiency. For the control features and technical requirements of the natural gas heater, the computer automatic control system for natural gas heater has been designed,and realizes the temperature and liquid level real time measurement and control. The system increases significantly the control accuracy of natural gas temperature, eliminates potential unsafety and improves production efficiency.

Investigation of hydrate formation in natural gas flow through underground transmission pipeline

2013 ◽  
Vol 15 ◽  
pp. 27-37 ◽  
Author(s):  
Mahmood Farzaneh-Gord ◽  
Hamid Reza Rahbari ◽  
Mahdi Bajelan ◽  
Lila Pilehvari
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Hydrate Formation ◽  
Transmission Pipeline ◽  
Flow Through ◽  
Natural Gas Flow

Part II. Research on the Performance of a Type of Internally Air-cooled Turbine Blade

1953 ◽  
Vol 167 (1) ◽  
pp. 351-370 ◽  
Author(s):  
D. G. Ainley
Keyword(s):  
Gas Flow ◽  
Thermal Stresses ◽  
Turbine Blades ◽  
Small Diameter ◽  
Rotor Blades ◽  
Air Cooling ◽  
Gas Temperature ◽  
Flow Through ◽  
Cooling Air ◽  
Practical Feasibility

A comprehensive series of tests have been made on an experimental single-stage turbine to determine the cooling characteristics and the overall stage performance of a set of air-cooled turbine blades. These blades, which are described fully in Part I of this paper had, internally, a multiplicity of passages of small diameter along which cool air was passed through the whole length of the blade. Analysis of the, test data indicated that, when a quantity of cooling air amounting to 2 per cent, by weight, of the total gas-flow through the turbine is fed to the row of rotor blades, an increase in gas temperature of about 270 deg. C. (518 deg. F.) should be permissible above the maximum allowable value for a row of uncooled blades made from the same material. The degree of cooling achieved throughout each blade was far from uniform and large thermal stresses must result. It appears, however, that the consequences of this are not highly detrimental to the performance of the present type of blading, it being demonstrated that the main effect of the induced thermal stress is apparently to transfer the major tensile stresses to the cooler (and hence stronger) regions of the blade. The results obtained from the present investigations do not represent a limit to the potentialities of internal air-cooling, but form merely a first exploratory step. At the same time the practical feasibility of air cooling is made apparent, and advances up to the present are undoubtedly encouraging.

Prediction of natural gas flow through chokes using support vector machine algorithm

2014 ◽  
Vol 18 ◽  
pp. 155-163 ◽  
Author(s):  
Ibrahim Nejatian ◽  
Mojtaba Kanani ◽  
Milad Arabloo ◽  
Alireza Bahadori ◽  
Sohrab Zendehboudi
Keyword(s):  
Support Vector Machine ◽  
Natural Gas ◽  
Gas Flow ◽  
Support Vector ◽  
Support Vector Machine Algorithm ◽  
Flow Through ◽  
Natural Gas Flow

Multi-Path Gas Ultrasonic Flow Meter Performance at Low Velocity

2005 ◽  
Author(s):  
Thomas B. Morrow
Keyword(s):  
Natural Gas ◽  
Thermal Stratification ◽  
Gas Flow ◽  
Low Flow ◽  
Large Temperature ◽  
Gas Temperature ◽  
Low Velocity ◽  
Flow Meters ◽  
Southwest Research Institute ◽  
Ultrasonic Flow Meter

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.

Models and Methods of Determining the Minimum Stack Metal Temperature During Sonic Blowdown of Natural Gas

2014 ◽  
Author(s):  
C. Hartloper ◽  
K. K. Botros ◽  
E. Abdalgawad ◽  
S. Reid
Keyword(s):  
Boundary Layer ◽  
Natural Gas ◽  
Wall Temperature ◽  
Steel Grade ◽  
Metal Temperature ◽  
Suitable Model ◽  
Gas Temperature ◽  
Flow Reynolds Number ◽  
Flow Through ◽  
Temperature Recovery

During a natural gas blowdown event, the flow through the blowdown stack is either sonic or supersonic at the stack exit. In this case, the temperature of the gas at the stack exit can drop significantly as the gas enthalpy is converted to kinetic energy. Depending on the initial pipeline temperature, it is possible for the gas temperature at the stack exit to drop below the minimum metal temperature specification of the stack steel grade. Traditionally in this case it is assumed that the blowdown-stack metal temperature follows the gas temperature; therefore, it would also drop below this minimum temperature. However, analogous to the decrease in the temperature of the gas as the velocity increases, the gas will increase in temperature as the velocity decreases near the wall of the stack due to the boundary layer. As such, the blowdown-stack wall temperature will not decrease to the same extent as the bulk gas temperature during the blowdown event. This phenomenon is referred to as wall temperature recovery. This paper describes the various models and methods for determining the extent of this temperature recovery via a parameter known as “recovery factor” which is a function of the flow Reynolds number, Prandtl number, Mach number, etc. These methods are evaluated and compared for several pipeline conditions, and the most suitable model is determined. It is recommended that fundamental blowdown testing on natural gas be conducted on well instrumented full-bore blowdown stack to validate the predictions by these methods.

scholarly journals Working Principle of Gas Turbine Meter Fluxi 2000/TZ and Gas Volume Converter

2020 ◽  
Vol 4 (8) ◽  
pp. 90-93
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Flow Rate ◽  
Gas Flow ◽  
Flow Meter ◽  
Measuring Device ◽  
Flow Meters ◽  
Working Principle ◽  
Flow Through ◽  
Gas Volume

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.

scholarly journals Optimally controlled heating of solid particles in a fluidised bed with a dispersive flow of the solid

2016 ◽  
Vol 37 (1) ◽  
pp. 65-76
Author(s):  
Artur Poświata ◽  
Zbigniew Szwast
Keyword(s):  
Gas Flow ◽  
Optimal Choice ◽  
Solid Particles ◽  
Heating Process ◽  
Fluidised Bed ◽  
Gas Temperature ◽  
Mixing Rate ◽  
Two Phase ◽  
The Maximum Principle ◽  
Axial Dispersion Coefficient

Abstract In this study the authors minimise the total process cost for the heating of solid particles in a horizontal fluidised bed by an optimal choice of the inlet heating gas temperature profile and the total gas flow. Solid particles flowed along the apparatus and were heated by a hot gas entering from the bottom of the fluidised apparatus. The hydrodynamics of the fluidised bed is described by a two-phase Kunii - Levenspiel model. We assumed that the gas was flowing only vertically, whereas solid particles were flowing horizontally and because of dispersion they could be additionally mixed up in the same direction. The mixing rate was described by the axial dispersion coefficient. As any economic values of variables describing analysing process are subject to local and time fluctuations, the accepted objective function describes the total cost of the process expressed in exergy units. The continuous optimisation algorithm of the Maximum Principle was used for calculations. A mathematical model of the process, including boundary conditions in a form convenient for optimisation, was derived and presented. The optimization results are presented as an optimal profile of inlet gas temperature. The influence of heat transfer kinetics and dispersion coefficients on optimal runs of the heating process is discussed. Results of this discussion constitute a novelty in comparison to information presented in current literature.

Liquefied natural gas as a backup fuel for TPP

2021 ◽  
Vol 14 (2) ◽  
pp. 84-91
Author(s):  
S. N. Lenev ◽  
V. B. Perov ◽  
A. N. Vivchar ◽  
A. V. Okhlopkov ◽  
O. Y. Sigitov ◽  
...  
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Large Scale ◽  
Gas Flow ◽  
National Policy ◽  
Liquefied Natural Gas ◽  
Fuel Oil ◽  
Gas Flows ◽  
Gas Industry ◽  
Gas Consumption

Major trends in the development of the gas industry point to a large-scale expansion of the liquefied natural gas (LNG) market, which continues to be a fast-growing segment compared to other energy sources. The national policy of the Russian Federation is aimed at developing the infrastructure of LNG complexes. This article analyses the world experience in the use of LNG complexes in gas consumption peak damping installations, which meet the conditions of LNG use as a backup fuel by PJSC Mosenergo branches (low-tonnage production combined with a large volume of LNG storage). It is shown that, in terms of the conditions of production and use of LNG at power plants, the most suitable are installations with 90–100% liquefaction of the incoming gas flow with an external refrigerating circuit using a mixed refrigerant or nitrogen, which provide the composition of regasified LNG almost identical to the composition of the source gas. The authors have formulated requirements for the development of energy-efficient LNG complexes at PJSC Mosenergo branches, including ensuring cycle energy consumption by expanding the network gas in the expander with utilization of refrigerating capacity in the liquefaction cycle, as well as cooling the compressed coolant of the refrigerating circuit by gas flows supplied further for combustion. The technological features of implementation of the LNG complex for production, storage and regasification of LNG as a reserve fuel for TPPs are reviewed. The study has shown that the most suitable power plant for the introduction of an LPG complex is TPP-22, for which a new fuel oil facility is being designed. Despite the current practice of using fuel oil and diesel fuel as backup fuels, LNG can have a competitive advantage through the use of secondary energy resources of TPPs. 

Dual-fuel Operation of Compression-ignition Engine Using Biodiesel for Pilot Injection

2012 ◽  
Author(s):  
Kelvin D. H. Bob-Manuel ◽  
Roy J. Crookes ◽  
Theodosios Korakianitis ◽  
Ashand M. Namasivayam
Keyword(s):  
Natural Gas ◽  
Environmental Protection Agency ◽  
Power Plants ◽  
Gas Flow ◽  
Stable Condition ◽  
Pressure Rise ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Maritime Industry ◽  
Compression Ignition Engine

Economic factor and stringent emission standards are imposing constraints on current and future operation of power plants in the maritime industry. Hence, research institutions have intensified investigation on technologies for emission control and economy using alternative and sustainable/renewable fuels to achieve friendly environment. In this study, the combustion characteristics of natural gas and hydrogen fuelled compression ignition engine operated under stable condition using either neat or emulsified rapeseed methyl ester (RME) for pilot ignition were investigated. Ignition delay and rate of cylinder pressure rise at 1000 and 1500 r/min were obtained at various gas flow rates while the emission of NOx, CO2 and HC were measured. NOx concentrations were compared with the regulated IMO MARPOL73/78 and United States Environmental Protection Agency (EPA) Tier 3 standards and were observed to be lower than the MARPOL 73/78 level at both speeds and the EPA standard at 1500 r/min for the minimum specification of category 1 engines. Emulsified RME fuel pilot injection reduced NOx emission at all test conditions using natural gas. The use of hydrogen subscribed mainly in the reduction of particulate matters (PM) and CO2 and hence will contribute in the reduction of greenhouse effect (climate change) on the environment.

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