Ejector Compression of Natural Gas for Small Turbines

1967 ◽  
Vol 182 (1) ◽  
pp. 449-462 ◽  
Author(s):  
G. Walker
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Cooling Water ◽  
Two Stage ◽  
Steam Consumption ◽  
Steam Content ◽  
Gas Compression ◽  
Steam Ejector

Natural-gas-fuelled total-energy systems for supplying the utility demands of residential and commercial buildings typically require 500 s.h.p. for the machinery drives. Although gas turbines are competitive prime movers in this size range, difficulties arise from the need to compress the natural gas fuel to the pressure of the turbine combustion chamber. In this study the use of non-condensing single-and two-stage steam-jet ejectors was analysed for gas compression to a pressure of 150 lb/in2. Steam-supply conditions from 5000 to 1000 lb/in2 and 800 to 1200°F were considered; methane was supplied at 15 lb/in2 and 60°F. The specific steam consumption (lb steam per lb gas) of a two-stage ejector was found to be much better than that of a single-stage ejector. The minimum specific steam consumption (6 lb steam per lb gas) occurred at the extreme steam conditions considered in the study. The steam-methane mixture this produced was not flammable when mixed in any proportion with air. Of several methods considered to reduce the steam content of the mixture delivered by the ejector, only one, post-ejector cooling and condensate removal, was suitable for analysis. Cooling-water flow rates in excess of 14 lb water per lb gas were necessary to produce potentially flammable mixtures. Estimates were made of the major effects on turbine engine performance arising from the use of a steam ejector for gas compression. A comparison was drawn for two idealized cycles and for two others in which realistic values of component efficiencies were included. In each series the gas was compressed by conventional means in one cycle and by means of a steam-jet ejector in the other. The steam injected with the methane in the turbine combustion chamber caused an appreciable decrease in the cycle temperatures and significant improvement in both the turbine output and thermal efficiency. When the additional heat input necessary to generate the steam for the ejector was included, the overall thermal efficiency of the steam-ejector cycle was less than that of the conventional cycle.

Design Analysis of a Micro Gas Turbine Combustion Chamber Burning Natural Gas

2012 ◽  
Author(s):  
André Perpignan V. de Campos ◽  
Fernando L. Sacomano Filho ◽  
Guenther C. Krieger Filho
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbines ◽  
Low Cost ◽  
Mixture Fraction ◽  
Combustion Model ◽  
Inlet Temperature ◽  
Gas Combustion ◽  
Micro Turbine

Gas turbines are reliable energy conversion systems since they are able to operate with variable fuels and independently from seasonal natural changes. Within that reality, micro gas turbines have been increasing the importance of its usage on the onsite generation. Comparatively, less research has been done, leaving more room for improvements in this class of gas turbines. Focusing on the study of a flexible micro turbine set, this work is part of the development of a low cost electric generation micro turbine, which is capable of burning natural gas, LPG and ethanol. It is composed of an originally automotive turbocompressor, a combustion chamber specifically designed for this application, as well as a single stage axial power turbine. The combustion chamber is a reversed flow type and has a swirl stabilized combustor. This paper is dedicated to the diagnosis of the natural gas combustion in this chamber using computational fluid dynamics techniques compared to measured experimental data of temperature inside the combustion chamber. The study emphasizes the near inner wall temperature, turbine inlet temperature and dilution holes effectiveness. The calculation was conducted with the Reynolds Stress turbulence model coupled with the conventional β-PDF equilibrium along with mixture fraction transport combustion model. Thermal radiation was also considered. Reasonable agreement between experimental data and computational simulations was achieved, providing confidence on the phenomena observed on the simulations, which enabled the design improvement suggestions and analysis included in this work.

Application of Aircraft Derivative and Heavy Duty Gas Turbines in the Process Industries

1979 ◽  
Author(s):  
M. C. Doherty ◽  
D. R. Wright
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Gas Turbines ◽  
Cooling Water ◽  
Offshore Platforms ◽  
Heavy Duty ◽  
Water Requirements ◽  
Process Industries ◽  
Gas Processing ◽  
Processing Plants

Typical applications of aircraft derivative and heavy duty gas turbines in petroleum production and refining, natural gas processing, ethylene, ammonia, LNG processing plants and offshore platforms are reviewed. Guidelines are included to illustrate how gas turbines can be applied to minimize fuel consumption and cooling water requirements and optimize space utilization.

Investigation of Hydrogen Enriched Natural Gas Flames in a SGT-700/800 Burner Using OH PLIF and Chemiluminescence Imaging

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Andreas Lantz ◽  
Robert Collin ◽  
Marcus Aldén ◽  
Annika Lindholm ◽  
Jenny Larfeldt ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Flame Front ◽  
Gas Turbines ◽  
Dynamic Pressure ◽  
Pressure Fluctuations ◽  
Burner Exit ◽  
Planar Laser ◽  
Industrial Gas Turbines ◽  
Dynamic Pressure Measurements

The effect of hydrogen enrichment to natural gas flames was experimentally investigated at atmospheric pressure conditions using flame chemiluminescence imaging, planar laser-induced fluorescence of hydroxyl radicals (OH PLIF), and dynamic pressure monitoring. The experiments were performed using a third generation dry low emission (DLE) burner used in both SGT-700 and SGT-800 industrial gas turbines from Siemens. The burner was mounted in an atmospheric combustion test rig at Siemens with optical access in the flame region. Four different hydrogen enriched natural gas flames were investigated; 0 vol. %, 30 vol. %, 60 vol. %, and 80 vol. % of hydrogen. The results from flame chemiluminescence imaging and OH PLIF show that the size and shape of the flame was clearly affected by hydrogen addition. The flame becomes shorter and narrower when the amount of hydrogen is increased. For the 60 vol. % and 80 vol. % hydrogen flames the flame has moved upstream and the central recirculation zone that anchors the flame has moved upstream the burner exit. Furthermore, the position of the flame front fluctuated more for the full premixed flame with only natural gas as fuel than for the hydrogen enriched flames. Measurements of pressure drop over the burner show an increase with increased hydrogen in the natural gas despite same air flow thus confirming the observation that the flame front moves upstream toward the burner exit and thereby increasing the blockage of the exit. Dynamic pressure measurements in the combustion chamber wall confirms that small amounts of hydrogen in natural gas changes the amplitude of the dynamic pressure fluctuations and initially dampens the axial mode but at higher levels of hydrogen an enhancement of a transversal mode in the combustion chamber at higher frequencies could occur.

Study of Humid Air Gas Turbine System by Experiment and Analysis

2011 ◽  
Author(s):  
Toru Takahashi ◽  
Yutaka Watanabe ◽  
Hidefumi Araki ◽  
Takashi Eta
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pilot Plant ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Medium Size ◽  
Water Recovery ◽  
Two Stage ◽  
Humid Air

Humid air gas turbine systems that are regenerative cycle using humidified air can achieve higher thermal efficiency than gas turbine combined cycle power plant (GTCC) even though they do not require a steam turbine, a high combustion temperature, or a high pressure ratio. In particular, the advanced humid air gas turbine (AHAT) system appears to be highly suitable for practical use because its composition is simpler than that of other systems. Moreover, the difference in thermal efficiency between AHAT and GTCC is greater for small and medium-size gas turbines. To verify the system concept and the cycle performance of the AHAT system, a 3MW-class pilot plant was constructed that consists of a gas turbine with a two-stage centrifugal compressor, a two-stage axial turbine, a reverse-flow-type single-can combustor, a recuperator, a humidification tower, a water recovery tower, and other components. As a result of an operation test, the planned power output of 3.6MW was achieved, so that it has been confirmed the feasibility of the AHAT as a power-generating system. In this study, running tests on the AHAT pilot plant is carried out over one year, and various characteristics such as the effect of changes in ambient temperature, part-load characteristics, and start-up characteristics were clarified by analyzing the data obtained from the running tests.

A System for Health State Determination of Natural Gas Compression Gas Turbines

2001 ◽  
Author(s):  
R. Bettocchi ◽  
M. Pinelli ◽  
P. R. Spina ◽  
M. Venturini ◽  
S. Sebastianelli
Keyword(s):  
Natural Gas ◽  
Path Analysis ◽  
Gas Turbines ◽  
Diagnostic System ◽  
Health State ◽  
Compression System ◽  
Gas Compression ◽  
State Determination ◽  
System Maintenance

This paper illustrates the policy and objectives in compression system maintenance and describes a system for the health state determination of natural gas compression gas turbines based on “Gas Path Analysis”. Some results of the application of the diagnostic system to gas turbines working in a natural gas compression plant are presented.

scholarly journals Study on nitrogen barrier protection of an airend oil-free compressor bearings in H2 compression

2022 ◽  
Vol 354 ◽  
pp. 00047
Author(s):  
Iulian Vladuca ◽  
Emilia Georgiana Prisăcariu ◽  
Cosmin Petru Suciu ◽  
Cristian Dobromirescu ◽  
Răzvan Edmond Nicoară
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Point Of View ◽  
Working Pressure ◽  
Gas Field ◽  
Gas Network ◽  
Gas Compression ◽  
Air Compression ◽  
Oil Injection ◽  
Injection Screw

The oil free compressors were specially designed for air compression. The National Research and Development Institute for Gas Turbines COMOTI gained a great deal of experience in producing/designing certified oil injection screw compressors for the natural gas field and for several years it has been focusing its research on the use of “dry” (oil-free) compressors in natural gas compression and more recently in hydrogen compression. Working with an explosive gas, one of an idea was to use a nitrogen barrier in oil bearing sealing, which are open source of gases in the atmosphere for such compressors. Worldwide, on-site nitrogen generators have been developed for a purity range of 95…99.5%, and that nitrogen can be supplied in any environment conditions. The present paper will address nitrogen flow with low percentage of oxygen for bearing sealing at the working pressure, the nitrogen consumption, ideas for H2 re-injection and the influence over the global efficiency of the process. Due to the Energy Strategy worldwide, and the studies regarding production, transport and storage of hydrogen in natural gas network, COMOTI has involved researches in developing such possibilities and to express a point of view in existing research in the newly created industry.

Model-Based Thermodynamic Analysis of a Hydrogen-Fired Gas Turbine with External Exhaust Gas Recirculation

2021 ◽  
Author(s):  
Thomas Bexten ◽  
Sophia Jörg ◽  
Nils Petersen ◽  
Manfred Wirsum ◽  
Pei Liu ◽  
...  
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Carbon Capture ◽  
Exhaust Gas ◽  
Model Based ◽  
Renewable Power ◽  
Renewable Power Generation

Abstract Climate science shows that the limitation of global warming requires a rapid transition towards net-zero emissions of greenhouse gases (GHG) on a global scale. Expanding renewable power generation is seen as an imperative measure within this transition. To compensate for the inherent volatility of renewable power generation, flexible and dispatchable power generation technologies such as gas turbines are required. If operated with CO2-neutral hydrogen or in combination with carbon capture plants, a GHG-neutral gas turbine operation could be achieved. An effective leverage to enhance carbon capture efficiency and a possible measure to safely burn hydrogen in gas turbines is the partial external recirculation of exhaust gas. By means of a model-based analysis of a gas turbine, the present study initially assesses the thermodynamic impact caused by a fuel switch from natural gas to hydrogen. Although positive trends such as increasing net electrical power output and thermal efficiency can be observed, the overall effect on the gas turbine process is only minor. In a following step, the partial external recirculation of exhaust gas is evaluated and compared both for the combustion of natural gas and hydrogen, regardless of potential combustor design challenges. The influence of altering working fluid properties throughout the whole gas turbine process is thermodynamically evaluated for ambient temperature recirculation and recirculation at an elevated temperature. A reduction in thermal efficiency can be observed as well as non-negligible changes of relevant process variables. These changes are more distinctive at a higher recirculation temperature

CFD Simulation of a Microturbine Annular Combustion Chamber Fuelled With Methane and Biomass Pyrolysis Syngas: Preliminary Results

2009 ◽  
Author(s):  
Francesco Fantozzi ◽  
Paolo Laranci ◽  
Michele Bianchi ◽  
Andrea De Pascale ◽  
Michele Pinelli ◽  
...  
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbines ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Calorific Value ◽  
Methane Combustion ◽  
Pollutant Emissions ◽  
Preliminary Results

Micro gas turbines could be profitably used, for distributed energy production, also exploiting low calorific value biomass-derived fuels, obtained by means of integrated pyrolysis and/or gasification processes. These synthesis gases show significant differences with respect to natural gas (in terms of composition, low calorific value, hydrogen content, tar and particulate matter content) that may turn into ignition problems, combustion instabilities, difficulties in emission control and fouling. CFD simulation of the combustion chamber is a key instrument to identify main criticalities arising when using these gases, in order to modify existing geometries and to develop new generation combustion chambers for use with low calorific value gases. This paper describes the numerical activity carried out to analyze the combustion process occurring inside an existing microturbine annular combustor. A CFD study of the combustion process performed with different computational codes is introduced and some preliminary results are reported in the paper. A comparison of results obtained with the different codes is provided, for the reference case of methane combustion. A first evaluation of the pollutant emissions and a comparison with the available experimental data is also provided in the paper, showing in particular a good matching of experimental data on NOx emissions at different load conditions. Moreover, the carried out investigation concerns the case of operation with a syngas fuel derived from pyrolysis of biomass and finally the case of syngas and natural gas co-firing. This combustion condition is simulated with a simple reduced chemical kinetic scheme, in order to assess only the key issues rising with this fuel in comparison with the case of methane combustion. The analysis shows that in case of syngas operation the combustor internal temperature hot spots are reduced and the primary zone flame tends to stabilize closer to the injector, with possible implications on the emission release.

Combustion of Natural Gas, Hydrogen and Bio-Fuels at Ultra-Wet Conditions

2011 ◽  
Author(s):  
Sebastian Go¨ke ◽  
Steffen Terhaar ◽  
Sebastian Schimek ◽  
Katharina Go¨ckeler ◽  
Christian O. Paschereit
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Pure Hydrogen ◽  
Nox Emissions ◽  
Steam Content ◽  
Wide Range ◽  
Air Mixing ◽  
Flame Flashback

Humidified Gas Turbines promise a significant increase in efficiency compared to the dry gas turbine cycle. In single cycle applications, efficiencies up to 60% seem possible with humidified turbines. Additionally, the steam effectively inhibits the formation of NOx emissions and also allows for operating the gas turbine on hydrogen-rich fuels. The current study is conducted within the European Advanced Grant Research Project GREENEST. The premixed combustion at ultra wet conditions is investigated for natural gas, hydrogen, and mixtures of both fuels, covering lower heating values between 27 MJ/kg and 120 MJ/kg. In addition to the experiments, the combustion process is also examined numerically. The flow field and the fuel-air mixing of the burner were investigated in a water tunnel using Particle Image Velocimetry and Laser Induced Fluorescence. Gas-fired tests were conducted at atmospheric pressure, inlet temperatures between 200°C and 370°C, and degrees of humidity from 0% to 50%. Steam efficiently inhibits the formation of NOx emissions. For all tested fuels, both NOx and CO emissions of below 10 ppm were measured up to near-stoichiometric gas composition at wet conditions. Operation on pure hydrogen is possible up to very high degrees of humidity, but even a relatively low steam content prevents flame flashback. Increasing hydrogen content leads to a more compact flame, which is anchored closer to the burner outlet, while increasing steam content moves the flame downstream and increases the flame volume. In addition to the experiments, the combustion process was modeled using a reactor network. The predicted NOx and CO emission levels agree well with the experimental results over a wide range of temperatures, steam content, and fuel composition.

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