The Flow Characteristics Analysis of Transonic around Delta-Wing to Separate Water from Natural Gas

The changes in flow channel area and convergence-expanding nozzle help to flow rate of natural gas to the sound speed, also increase diameter to accelerate flow velocity and finally reach transonic flow condition. At this point, the temperature drop makes saturated water in natural gas condenses into droplets, generates swirl around the delta-wing, realize gas-water separation. This paper concentrates on Flent6.1 software process gas flow around a delta wing simulation, explains expansion angle and attack angle of delta-wing, determines a reasonable delta-wing attack angle is 10°, pipeline expansion angle is 0.29°, and obtains velocity vector, mach number, total pressure, static temperature and other flow field details of the attack angle and expansion angle, which lay foundation for production and application of the technology.

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Efficiency Improvement of Vacuum Carburizing by Using Natural Gas

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.118.97 ◽

2006 ◽

Vol 118 ◽

pp. 97-102

Author(s):

Masahiro Okumiya ◽

Satoshi Hagi ◽

Kazuya Orita ◽

Yoshiki Tsunekawa ◽

Yoshito Umeda ◽

...

Keyword(s):

Natural Gas ◽

Carbon Concentration ◽

Gas Flow ◽

Infiltration Rate ◽

Unsaturated Hydrocarbon ◽

Specimen Surface ◽

Vacuum Carburizing ◽

Hydrocarbon Gases ◽

Process Gas ◽

Natural Gas Flow

Acetylene and ethylene are frequently used in vacuum carburizing in Japan. In this study the natural gas which is available from the lifeline is applied to vacuum carburizing. The gas composition inside the furnace was analyzed by the gas chromatography in order to examine the carbon infiltration mechanism. Unsaturated hydrocarbon gases (such as acetylene and ethylene) are generated from the natural gas. The effect of acetylene concentration in the furnace on the carbon infiltration rate was investigated. The carbon amount which infiltrates into the steel increases, as acetylene concentration in furnace increases. It is possible that carbon concentration of specimen surface increases to the cementite precipitation concentration in the short term, when natural gas flow rate increases in the initial carburizing stage. After that, carbon concentration of specimen surface does not decrease, even if the natural gas flow decreases, because carbon atoms which are consumed for diffusion to inside are sufficiently supplied. By using this method, inhibition of soot generation, reduction of process gas and shortening of the carburizing period are possible. The carbon concentration profile of the vacuum carburized specimen was compared with the simulation.

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Techno-Economic Assessment of Turboexpander Application at Natural Gas Regulation Stations

Energies ◽

10.3390/en12040755 ◽

2019 ◽

Vol 12 (4) ◽

pp. 755 ◽

Cited By ~ 4

Author(s):

Szymon Kuczyński ◽

Mariusz Łaciak ◽

Andrzej Olijnyk ◽

Adam Szurlej ◽

Tomasz Włodek

Keyword(s):

Natural Gas ◽

Gas Flow ◽

Electric Energy ◽

Economic Assessment ◽

Gas Pressure ◽

Operational Parameters ◽

Pressure Regulator ◽

Correct Operation ◽

Process Gas ◽

Gas Expansion

During the natural gas pipeline transportation process, gas stream pressure is reduced at natural gas regulation stations (GRS). Natural gas pressure reduction is accompanied by energy dissipation which results in irreversible exergy losses in the gas stream. Energy loss depends on the thermodynamic parameters of the natural gas stream on inlet and outlet gas pressure regulation and metering stations. Recovered energy can be used for electricity generation when the pressure regulator is replaced with an expander to drive electric energy generation. To ensure the correct operation of the system, the natural gas stream should be heated, on inlet to expander. This temperature should be higher than the gas stream during choking in the pressure regulator. The purpose of this research was to investigate GRS operational parameters which inﬂuence the efﬁciency of the gas expansion process and to determine selection criteria for a cost-effective application of turboexpanders at selected GRS, instead of pressure regulators. The main novelty presented in this paper shows investigation on discounted payback period (DPP) equation which depends on the annual average natural gas flow rate through the analyzed GRS, average annual level of gas expansion, average annual natural gas purchase price, average annual produced electrical energy sale price and CAPEX.

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Gas flow characteristics analysis of SF6 circuit breaker using similarity theory

The Journal of Engineering ◽

10.1049/joe.2018.8677 ◽

2019 ◽

Vol 2019 (16) ◽

pp. 2420-2425

Author(s):

Liying Li ◽

Hai Chen ◽

Yaqian Zhang ◽

Wei Liu ◽

Xiaoming Liu

Keyword(s):

Gas Flow ◽

Similarity Theory ◽

Circuit Breaker ◽

Flow Characteristics ◽

Characteristics Analysis ◽

Sf6 Circuit Breaker

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Improvement of Poppet Valve Injection Performance in Large-Bore Natural Gas Engines

ASME 2004 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2004-0845 ◽

2004 ◽

Author(s):

Gi-Heon Kim ◽

Allan Kirkpatrick ◽

Charles Mitchell

Keyword(s):

Natural Gas ◽

Pressure Loss ◽

Internal Combustion Engines ◽

Gas Flow ◽

Flow Characteristics ◽

Stagnation Pressure ◽

Natural Gas Engines ◽

Poppet Valve ◽

Flow Through ◽

Poppet Valves

Poppet valves have been used as fuel delivery mechanisms in internal combustion engines due to their excellent sealing characteristics. For example, in large-bore stationary natural gas engines, gas is directly injected by a poppet valve into the engine cylinder. The objectives of this paper are to show that a significant amount of stagnation pressure is lost during the gas flow through a conventional poppet valve and to suggest design improvements to obtain more efficient poppet valves with reduced stagnation pressure loss. In this paper, simple converging-diverging nozzles are incorporated into the poppet valve configuration to reduce the stagnation pressure loss originating from compressible flow structures. Numerical simulations of the gas flow through various poppet valve geometries were performed. Both push and pull poppet valve geometries with nozzle were studied. The stagnation pressure losses, momentum delivery downstream and downstream flow characteristics of the jets from conventional poppet valves and the modified valves were compared. A pressure-based valve injection efficiency was defined and used to compare the valve injection performance. A mixing fraction parameter was also defined to compare valve performance in a moving piston simulation. The results indicate that a conventional poppet valve is an inefficient mechanism to deliver momentum to the fuel-air mixture. Comparison of the results indicates that it is possible to make significant improvements of injection performance in momentum delivery by incorporating well-designed nozzles into the poppet valve geometry.

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SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

Energy Technologies & Resource Saving ◽

10.33070/etars.3.2017.01 ◽

2017 ◽

pp. 3-18 ◽

Cited By ~ 1

Author(s):

B.S. Soroka ◽

V.V. Horupa

Keyword(s):

Natural Gas ◽

Flow Rate ◽

Gas Flow ◽

Renewable Energy Sources ◽

Combustion Process ◽

Orifice Diameter ◽

Firing Process ◽

Gas Flow Rate ◽

Gas Combustion ◽

Gas Stoves

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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