A Computational Study of Hydrogen Substitution Effects on the Combustion Performance for a Micro Gas Turbine

2011 ◽  
Author(s):  
Hsin-Yi Shih ◽  
Chi-Rong Liu
Keyword(s):  
Gas Turbine ◽  
Flame Temperature ◽  
Substitution Effects ◽  
Pure Hydrogen ◽  
Gas Temperature ◽  
Micro Gas Turbine ◽  
Combustion Performance ◽  
Pure Methane ◽  
Hydrogen Substitution ◽  
Blended Fuels

The effects of hydrogen substitution on methane/air combustion in a micro gas turbine were studied in this work. The combustion performance and emission characteristics of a can type combustor were investigated with model simulations 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. With hydrogen being the substituent, not a supplement to methane, the detailed flame structures, distributions of flame temperature and flow velocity, and gas emissions were presented and compared by using a fraction of hydrogen to substitute methane in the combustor. For the scenarios from pure methane to pure hydrogen, results show the flame temperature and exit gas temperature increase when only 10% methane is substituted. But as hydrogen substitution percentage increases, the flame temperature and exit gas temperature decrease because of a power shortage caused by lower mass flow rate and heating value of the resulting blended fuels, although the pattern factor drops drastically compared to that of pure methane. As the fuel inlet velocity decreases from 100 m/s to 20 m/s, the high temperature region shifts to the side of the combustor due to the high diffusivity of hydrogen. Increasing hydrogen substitution percentage at a fixed fuel injection velocity reduces NOx emission due to lower flame temperature, but CO emissions increase continually with increasing hydrogen substitution percentage because oxygen depletion for methane/air combustion. Before hydrogen blended fuels or pure hydrogen 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.

scholarly journals Emissions and Combustion Performance of a Micro Gas Turbine Powered with Liquefied Wood and its Blends

2017 ◽  
Vol 142 ◽  
pp. 297-302 ◽  
Author(s):  
Marco Buffi ◽  
Alessandro Cappelletti ◽  
Tine Seljak ◽  
Tomaž Katrašnik ◽  
Agustin Valera-Medina ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Micro Gas Turbine ◽  
Combustion Performance ◽  
Liquefied Wood

A methodology for identifying the most suitable measurements for engine level and component level gas path diagnostics of a micro gas turbine

2021 ◽  
pp. 095440622110303
Author(s):  
SS Talebi ◽  
AM Tousi ◽  
A Madadi ◽  
M Kiaee
Keyword(s):  
Path Analysis ◽  
Gas Turbine ◽  
Smart Grids ◽  
Gas Turbines ◽  
Complex Dynamics ◽  
Gas Temperature ◽  
Component Level ◽  
Part Load ◽  
Micro Gas Turbine ◽  
Process Gas

Recently, the utilization of micro gas turbines in smart grids are rising that makes the part-load operation principal situation of the engine service. This leads to faster life consumption that increases the importance of the diagnostics process. Gas path analysis is an effective method for gas turbine diagnostics. Complex dynamics of gas turbine induces challenging conditions to perform applicable gas path analysis. This study aims to facilitate MGT gas path diagnostics through reducing the number of monitoring parameters and preparation a pattern for engine level and component level health assessment in both full and part load operation of a recuperated micro gas turbine. To attain this goal a model is proposed to simulate MGT off-design performance which is validated against experimental data in healthy and degraded operation modes. Fouling in compressor, turbine and recuperator and erosion in compressor and turbine as the most common degradations in the gas turbine are considered. The fault simulation is performed by changing the health parameters of gas path components. According to the result investigation, a matrix comprises deviation contours of four parameters, Power, fuel flow, compressor discharge pressure, and exhaust gas temperature is presented and analyzed. The analysis shows that monitoring these parameters makes it possible to perform engine level and component level diagnostics through evaluating a binary code (generated by mentioned parameter variations) against the fault effects pattern in different load fractions and fault severities. The simulation also showed that the most power drop occurred under the compressor fouling by about 8.7% while the most reduction in thermal efficiency is observed under recuperator fouling by about 7.84%. Furthermore, the investigation showed the maximum decrease in the surge margin induced by the compressor fouling during the lower part-load operation by about 45.7% while in the higher loads created by the turbine fouling by about 14%.

Simulation Model and Experimental Validation of a CHP Plant With Micro Gas Turbine

2012 ◽  
Author(s):  
Marco Badami ◽  
Mauro Ferrero ◽  
Armando Portoraro
Keyword(s):  
Simulation Model ◽  
Gas Turbine ◽  
Small Scale ◽  
Gas Temperature ◽  
Data Set ◽  
Micro Gas Turbine ◽  
Limit Value ◽  
Partial Load ◽  
Main Components ◽  
Energy And Momentum

The paper deals with a simulation model, developed in Matlab Simulink®, of a small-scale Combined Heat and Power (CHP) plant based on a recuperated micro gas turbine (mGT). A minimum data set, mainly obtainable from datasheets, was defined, that allows the model to simulate different mGT plants in the small-scale range with a good accuracy. The model implements the mass, energy and momentum equations of the main components of the power plant. A double control system has also been developed, with the aim of maintaining the rotational speed of the turbine /compressor assembly at the nominal fixed value, and at limiting the Exhaust Gas Temperature (EGT) below the limit value. The model has been validated by means of experimental data obtained from a commercial mGT (100 kWel, 170 kWth), installed at the Politecnico di Torino, whose energetic characterization has been performed both at rated and at partial load conditions. The layout and the characteristics of the measurement system are also described in the paper.

Micro Gas Turbine Combustion Chamber Design and CFD Analysis

2004 ◽  
Author(s):  
Joao Parente ◽  
Giulio Mori ◽  
Viatcheslav V. Anisimov ◽  
Giulio Croce
Keyword(s):  
Gas Turbine ◽  
Design Process ◽  
Preliminary Analysis ◽  
Cooling System ◽  
System Development ◽  
Experimental Testing ◽  
Flame Temperature ◽  
Turbulence Models ◽  
Cfd Analysis ◽  
Micro Gas Turbine

In the framework of the non-standard fuel combustion research in micro-small turbomachinery, a newly designed micro gas turbine combustor for a 100-kWe power plant in CHP configuration is under development at the Ansaldo Ricerche facilities. Combustor design starts from a single silo chamber shape with two fuel lines, and is associated with a radial swirler flame stabiliser. Lean premix technique is adopted to control both flame temperature and NOx production. Combustor design process envisages two major steps, i.e. diagnostics-focussed design for methane only and experimentally validated design optimisation with suitable burner adaptation to non-standard fuels. The former step is over, as the first prototype design is ready for experimental testing. Step two is now beginning with a preliminary analysis of the burner adaptation to non-standard fuels. The present paper focuses on the first step of the combustor development. In particular, main design criteria for both burner and liner cooling system development are presented. Besides, design process control invoked both 2D and 3D CFD analysis. Two turbulence models, FLUENT standard k-ε model and Reynolds Stress Model (RSM), are refereed and the results compared. Here both a detailed analysis of CFD results and a preliminary analysis of main chemical kinetic phenomena are discussed.

Utilizing of biodiesel fuel for micro gas turbine combustion performance

2021 ◽  
Author(s):  
Muhammad Roslan Rahim ◽  
Mohammad Nazri Mohd Jaafar ◽  
A. I. M. Shaiful ◽  
Wan Zaidi Wan Omar ◽  
Norazila Othman
Keyword(s):  
Gas Turbine ◽  
Biodiesel Fuel ◽  
Micro Gas Turbine ◽  
Combustion Performance ◽  
Gas Turbine Combustion

Prediction of lean blowout performance on variation of combustor inlet area ratio for micro gas turbine combustor

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kirubakaran V. ◽  
Naren Shankar R.
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Equivalence Ratio ◽  
Area Ratio ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Content Type ◽  
Lean Blowout ◽  
Micro Gas Turbine ◽  
Primary Zone

Purpose This paper aims to predict the effect of combustor inlet area ratio (CIAR) on the lean blowout limit (LBO) of a swirl stabilized can-type micro gas turbine combustor having a thermal capacity of 3 kW. Design/methodology/approach The blowout limits of the combustor were predicted predominantly from numerical simulations by using the average exit gas temperature (AEGT) method. In this method, the blowout limit is determined from characteristics of the average exit gas temperature of the combustion products for varying equivalence. The CIAR value considered in this study ranges from 0.2 to 0.4 and combustor inlet velocities range from 1.70 to 6.80 m/s. Findings The LBO equivalence ratio decreases gradually with an increase in inlet velocity. On the other hand, the LBO equivalence ratio decreases significantly especially at low inlet velocities with a decrease in CIAR. These results were backed by experimental results for a case of CIAR equal to 0.2. Practical implications Gas turbine combustors are vulnerable to operate on lean equivalence ratios at cruise flight to avoid high thermal stresses. A flame blowout is the main issue faced in lean operations. Based on literature and studies, the combustor lean blowout performance significantly depends on the primary zone mass flow rate. By incorporating variable area snout in the combustor will alter the primary zone mass flow rates by which the combustor will experience extended lean blowout limit characteristics. Originality/value This is a first effort to predict the lean blowout performance on the variation of combustor inlet area ratio on gas turbine combustor. This would help to extend the flame stability region for the gas turbine combustor.

Effects of Equivalence Ratio on the Off-Design Combustion Performance of Adjustable Fuel Feeding Combustor for a Micro-Gas Turbine

2017 ◽  
Author(s):  
Chang Xing ◽  
Penghua Qiu ◽  
Li Liu ◽  
Wenkai Shen ◽  
Yajin Lyu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Characteristic Number ◽  
Outlet Temperature ◽  
Operation Performance ◽  
Feeding Method ◽  
Micro Gas Turbine ◽  
Combustion Performance ◽  
Fuel Flow ◽  
Combustion Technology ◽  
Fuel Tube

To improve off-design operation performance of micro-gas turbine, we proposed an adjustable fuel feeding combustor (AFFC), and it employed the lean premixed swirling combustion technology and the adjustable fuel feeding method (AFFM). The AFFM was achieved by switching the various working groups of main fuel tube, and represented by its unique characteristic number (U). To verify the availability of adopted models, the AFFC combustion performance was investigated numerically at different equivalence ratios (ϕ) in ANSYS CFX. The results indicate that NO emission has various trends with the rising U under different ϕ due to the coupling influence of fuel flow and jet velocity in each working main fuel tube. Although the AFFM has almost no effect on the distribution of outlet temperature and the length of primary recirculation zone, the maximum and non-uniform coefficient of outlet temperature increase with the rising U.

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.

Numerical Simulations of Low-Btu Coal Gas Combustion in a Gas Turbine Combustor

1991 ◽  
Author(s):  
Ajay K. Agrawal ◽  
Tah-Teh Yang
Keyword(s):  
Gas Turbine ◽  
Mixture Fraction ◽  
Flame Temperature ◽  
Three Dimensional ◽  
Reacting Flow ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Gas Combustion ◽  
Complete Combustion ◽  
Coal Gas

A numerical model for turbulent reacting flow is described and applied for predictions in an industrial gas turbine combustor operating on low-Btu coal gas. The model, based on fast-reaction limit, used Favre averaged conservation equations with the standard k-ε model of turbulence. Effects of turbulent fluctuations on chemistry are described statistically in terms of the mean, variance and probability density function (assumed to be β-distribution) of the mixture fraction. Two types of geometric approximations, namely axisymmetric and three-dimensional, were used to model the combustor. Computations were performed with (a) no swirl (b) weak swirl and (c) strong swirl at the fuel and primary air inlets. Essentially, the same bulk mean temperature distributions were obtained for axisymmetric and three-dimensional calculations while the computed pattern factors and the liner wall temperatures for the two differed significantly. Complete combustion was predicted with strong swirl, a result supported by the available test data. The maximum liner wall temperature predicted for three-dimensional calculations compared favorably with the experimental data while the predicted maximum exhaust gas temperature differed by ≈120 K. The difference was attributed to measurement uncertainties, model assumptions and lack of accurate data at the inlets. The maximum flame temperature was below 1,850 K indicating that thermal NOx may be insignificant.

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