A Computational Investigation of Syngas Substitution Effects on the Combustion Characteristics for a Micro Gas Turbine

2012 ◽  
Author(s):  
Chi-Rong Liu ◽  
Hsin-Yi Shih
Keyword(s):  
Carbon Monoxide ◽  
High Temperature ◽  
Natural Gas ◽  
Gas Turbine ◽  
Experimental Testing ◽  
Combustion Characteristics ◽  
Flame Speed ◽  
Cfd Modeling ◽  
Substitution Effects ◽  
Micro Gas Turbine

The aim of this study is to investigate the effects of syngas substitution on combustion characteristics for a micro gas turbine. For syngas combustion, the ratio of hydrogen and carbon monoxide is varied depending on the process techniques and it could be critical for gas turbine combustion applications. The combustion characteristics of syngas are quite different from natural gas, for example, the flame speed of hydrogen is higher than that of natural gas, but the flame speed of carbon monoxide is lower. In order to understand the performance differences between syngas fuel and natural gas, the combustion and emission characteristics of a can type combustor were investigated with model simulations using the commercial code STAR-CD, where a three-dimensional compressible k-ε model for turbulent flows and presumed probability density function for chemical process between methane/syngas/air mixtures were constructed. For the fuel injection velocity of 60 m/s and using hydrogen-rich (H2/CO = 80/20) syngas, the high temperature regions are separated and close to the sides of the combustor with some syngas fuel substituted for methane, but the high temperature zones move back to the core region of the combustor by substituting more syngas fuel. The CO2 and NOx emissions are decreased with 10% methane substituted by syngas, but increased with decreasing methane percentages. The detailed flame structures, distributions of flame temperature and flow velocity, and gas emissions of the combustor were presented and compared by using syngas composition and methane percentage of blended fuel mixture as the parameters. The exit temperature profiles and pattern factor were also discussed. Before syngas fuels are used as an alternative fuel for the micro gas turbine, further experimental testing are needed as the CFD modeling results provide a guidance for the improved designs of the combustor.

Combustion Characteristics and Hydrogen Addition Effects on the Performance of a Can Combustor for a Micro Gas Turbine

2010 ◽  
Author(s):  
Hsin-Yi Shih ◽  
Chi-Rong Liu
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Temperature Region ◽  
Fuel Injection ◽  
Flame Temperature ◽  
Combustion Characteristics ◽  
High Temperature Region ◽  
Micro Gas Turbine ◽  
Blended Fuel ◽  
Co Emission

To better understand the combustion performance by using hydrogen/methane blended fuels for an innovative micro gas turbine which is designed originally as a natural gas fired engine, the combustion characteristics of a can type combustor has been modeled and the effects of hydrogen amount were investigated. The simulations were performed using the commercial code STAR-CD, in which the three-dimension compressible k-ε turbulent flow mode and presumed probability density function for chemical reaction between methane/hydrogen/air mixtures were used. The results showed the detailed flame structures including the flow fields, distributions of flame temperature, major species and gas emissions. A variable volumetric fraction of hydrogen from 0% to 80% and the fuel injection velocities of this blended fuel ranging from 20 m/s to 60 m/s were studied. When hydrogen amount is higher, the flame temperature and exit gas temperature increase; high temperature region becomes wider and shifts to the intermediate zone. As fuel inlet velocity decreases from 60 m/s to 20 m/s, the high temperature region shifts to the side of the combustor due to the high diffusivity of hydrogen. Compared to the combustion using pure methane, NOx emissions increase with blended fuel, but the increase of hydrogen amount does not produce any significant effect over emission level of NOx. However, CO emission reduction is more remarkable at low hydrogen fraction, but the level of CO emission increases drastically when the fuel injection velocity is lower. Further modifications of the combustor designs including the fuel injection and cooling strategies are needed to improve the combustion performance for the micro gas turbine engine with hydrogen blended fuel as an alternative.

Model Analysis of Syngas Combustion and Emission for a Micro Gas Turbine

2014 ◽  
Author(s):  
Chi-Rong Liu ◽  
Hsin-Yi Shih
Keyword(s):  
Gas Turbine ◽  
Heat Input ◽  
Combustion Process ◽  
Cfd Modeling ◽  
Substitution Effects ◽  
Emission Characteristics ◽  
Nox Emissions ◽  
Micro Gas Turbine ◽  
Temperature Distributions ◽  
Flame Structures

The purpose of this study is to investigate the combustion and emission characteristics of syngas fuels applied in a micro gas turbine, which is originally designed for a natural gas fired engine. The computation results were conducted by the commercial CFD software STAR-CD, where the three-dimension compressible k-ε model for turbulent flow and PPDF (Presumed Probability Density Function) model for combustion process were constructed. As the syngas are substituted for methane, the total heat input from the blended fuels and the fuel flow rates are varied with syngas compositions and syngas substitution percentages. The computed results presented the syngas substitution effects on the combustion and emission characteristics at different syngas percentages (up to 80%) for two typical syngas compositions and the conditions where syngas applied at fixed heat input were examined. Results showed the flame structures varied with different syngas substitution percentages. The high temperature regions were dense and concentrated on the core of the primary zone for H2-rich syngas, and then shifted to the sides of the combustor when syngas percentages were high. The NOx emissions decreased with increasing syngas percentages, but NOx emissions are higher at higher hydrogen content for the same syngas percentage. The CO2 emissions also decreased at 10% syngas substitution, but then increased as syngas percentage increased. Only using H2-rich syngas could produce less carbon dioxide. The detailed flame structures, temperature distributions, and gas emissions of the combustor were presented and compared. The exit temperature distributions and pattern factor were also discussed. Before syngas fuels are utilized as an alternative fuel for the micro gas turbine, further experimental testing are needed as the CFD modeling results provide a guidance for the improved designs of the combustor.

Combustion Characteristics of Small Size Gas Turbine Combustor Fueled by Biomass Gas Employing Flameless Combustion

2007 ◽  
Author(s):  
Masato Hiramatsu ◽  
Yoshifumi Nakashima ◽  
Sadamasa Adachi ◽  
Yudai Yamasaki ◽  
Shigehiko Kaneko
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Flameless Combustion ◽  
Engine Exhaust ◽  
Micro Gas Turbine

One approach to achieving 99% combustion efficiency (C.E.) and 10 ppmV or lower NOx (at 15%O2) in a micro gas turbine (MGT) combustor fueled by biomass gas at a variety of operating conditions is with the use of flameless combustion (FLC). This paper compares experimentally obtained results and CHEMKIN analysis conducted for the developed combustor. As a result, increase the number of stage of FLC combustion enlarges the MGT operation range with low-NOx emissions and high-C.E. The composition of fuel has a small effect on the characteristics of ignition in FLC. In addition, NOx in the engine exhaust is reduced by higher levels of CO2 in the fuel.

Assessment of the Potential of Combined Micro Gas Turbine and High Temperature Fuel Cell Systems

2002 ◽  
Author(s):  
Dieter Bohn ◽  
Nathalie Po¨ppe ◽  
Joachim Lepers
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Advanced Materials ◽  
Cell Systems ◽  
Micro Gas Turbine ◽  
Technological Assessment

The present paper reports a detailed technological assessment of two concepts of integrated micro gas turbine and high temperature (SOFC) fuel cell systems. The first concept is the coupling of micro gas turbines and fuel cells with heat exchangers, maximising availability of each component by the option for easy stand-alone operation. The second concept considers a direct coupling of both components and a pressurised operation of the fuel cell, yielding additional efficiency augmentation. Based on state-of-the-art technology of micro gas turbines and solid oxide fuel cells, the paper analyses effects of advanced cycle parameters based on future material improvements on the performance of 300–400 kW combined micro gas turbine and fuel cell power plants. Results show a major potential for future increase of net efficiencies of such power plants utilising advanced materials yet to be developed. For small sized plants under consideration, potential net efficiencies around 70% were determined. This implies possible power-to-heat-ratios around 9.1 being a basis for efficient utilisation of this technology in decentralised CHP applications.

scholarly journals Thermodynamic modelling and efficiency analysis of a class of real indirectly fired gas turbine cycles

2009 ◽  
Vol 13 (4) ◽  
pp. 41-48
Author(s):  
Zheshu Ma ◽  
Zhenhuan Zhu
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Waste Heat ◽  
Operational Parameters ◽  
Forecast Performance ◽  
Micro Gas Turbine ◽  
Temperature Heat

Indirectly or externally-fired gas-turbines (IFGT or EFGT) are novel technology under development for small and medium scale combined power and heat supplies in combination with micro gas turbine technologies mainly for the utilization of the waste heat from the turbine in a recuperative process and the possibility of burning biomass or 'dirty' fuel by employing a high temperature heat exchanger to avoid the combustion gases passing through the turbine. In this paper, by assuming that all fluid friction losses in the compressor and turbine are quantified by a corresponding isentropic efficiency and all global irreversibilities in the high temperature heat exchanger are taken into account by an effective efficiency, a one dimensional model including power output and cycle efficiency formulation is derived for a class of real IFGT cycles. To illustrate and analyze the effect of operational parameters on IFGT efficiency, detailed numerical analysis and figures are produced. The results summarized by figures show that IFGT cycles are most efficient under low compression ratio ranges (3.0-6.0) and fit for low power output circumstances integrating with micro gas turbine technology. The model derived can be used to analyze and forecast performance of real IFGT configurations.

Experimental Investigation of the Impact of Biogas on a 3 kW Micro Gas Turbine FLOX®-Based Combustor

2020 ◽  
Author(s):  
Hannah Seliger-Ost ◽  
Peter Kutne ◽  
Jan Zanger ◽  
Manfred Aigner
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Waste Heat ◽  
Electrical Power ◽  
Atmospheric Conditions ◽  
Micro Gas Turbine ◽  
Fuel Mixtures ◽  
Carbon Dioxide Co2 ◽  
Electrical Power Output ◽  
The Impact

Abstract The use of biogas has currently two disadvantages. Firstly, processing biogas to natural gas quality for feeding into the natural gas grid is a rather energy consuming process. Secondly, the conversion into electricity directly in biogas plants produces waste heat, which largely cannot be used. Therefore, a feed-in of the desulfurized and dry biogas to local biogas grids would be preferable. Thus, the biogas could be used directly at the end consumer for heat and power production. As biogas varies in its methane (CH4) and carbon dioxide (CO2) content, respectively, this paper studies the influence of different biogas mixtures compared to natural gas on the combustion in a FLOX®-based six nozzle combustor. The single staged combustor is suitable for the use in a micro gas turbine (MGT) based combined heat and power (CHP) system with an electrical power output of 3 kW. The combustor is studied in an optically accessible atmospheric test rig, as well as integrated into the MGT system. This paper focuses on the influence of the admixture of CO2 to natural gas on the NOX and CO emissions. Furthermore, at atmospheric conditions the shape and location of the heat release zone is investigated using OH* chemiluminescence (OH* CL). The combustor could be stably operated in the MGT within the complete stationary operating range with all fuel mixtures.

scholarly journals Geometry optimization of a commercial annular RQL combustor of a micro gas turbine for use with natural gas and vegetal oils

2017 ◽  
Vol 126 ◽  
pp. 875-882 ◽  
Author(s):  
Paolo Laranci ◽  
Mauro Zampilli ◽  
Michele D’Amico ◽  
Pietro Bartocci ◽  
Gianni Bidini ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Geometry Optimization ◽  
Micro Gas Turbine

Enhanced Gas Turbine Combustor Performance Using H2-Enriched Natural Gas

1999 ◽  
Author(s):  
Jeffrey N. Phillips ◽  
Richard J. Roby
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Flame Speed ◽  
Gas Turbine Combustor ◽  
Flammability Limits ◽  
Combustion Performance ◽  
Exhaust Heat ◽  
Efficient Combustion

A screening level study has been carried out to examine the potential of using H2-enriched natural gas to improve the combustion performance of gas turbines. H2 has wider flammability limits and a higher flame speed than methane. Many previous studies have shown that when H2 is added to fuel, more efficient combustion and lower emissions will result. However, to date no commercial attempt has been made to improve the combustion performance of a natural gas-fired gas turbine by supplementing the fuel with H2. Four potential options for supplementing natural gas with H2 have been analyzed. Three of these options use the exhaust heat of the gas turbine either directly or indirectly to partially reform methane. The fourth option uses liquid H2 supplied from an industrial gas producer.

Sign in / Sign up

Export Citation Format

Share Document