Improvement of the Outlet Temperature Distribution of a Dual-Fuel Gas Turbine Combustor by a Simplified CFD Model

2012 ◽  
Author(s):  
Paolo Gobbato ◽  
Andrea Lazzaretto ◽  
Massimo Masi
Keyword(s):  
Gas Turbine ◽  
Dual Fuel ◽  
Outlet Section ◽  
Outlet Temperature ◽  
Computational Domain ◽  
Gas Turbine Combustor ◽  
Fuel Gas ◽  
Turbine Inlet ◽  
Primary Zone ◽  
Better Than

The mixing process within the dilution zone noticeably affects the temperature field in the outlet section of a gas turbine combustor. In fact, dilution jets lower the temperature of the hot flow exiting the primary zone establishing suitable temperature profile and pattern factor at the combustor outlet. Thus, the dilution zone design has a significant impact on performance and durability of the turbine. In this study, a dual-fuel gas turbine combustor is investigated by a commercial finite-volume CFD code. The computational domain extends from the compressor discharge to the gas turbine inlet and it is meshed with a coarse grid since it was originally conceived for thermoacoustic analysis. The model has been already validated throughout measurements acquired during full scale isothermal and reactive tests. On the basis of the results of reactive simulations, several solutions of the dilution zone are designed to improve the uniformity of radial and circumferential temperature at the turbine inlet. The designed configurations feature number, arrangement and diameter of dilution holes which differ from the commercial configuration providing four identical dilution holes equally spaced. Advantages and drawbacks of each dilution zone layout are supported by results of numerical calculations. The results suggest that the solutions featuring two dilution holes perform better than the actual layout.

Measurements Inside a Bluff-Body Stabilized Gas Turbine Combustor for Application of Pressurized Biomass Derived Low Calorific Value Fuel Gas and Comparison of the Results: Part 2

2006 ◽  
Author(s):  
Marco van der Wel ◽  
Wiebren de Jong ◽  
Hartmut Spliethoff
Keyword(s):  
Gas Turbine ◽  
Bluff Body ◽  
Calorific Value ◽  
Combustion Efficiency ◽  
Medium Size ◽  
Gas Turbine Combustor ◽  
Fuel Gas ◽  
Primary Zone ◽  
Secondary Air ◽  
Comparison Of The Results

In our previous paper [Van der Wel (2005)] the main results about combustion efficiency and emissions have been presented of experiments with a medium size (TUD) combustor of 1.5 MWth operated on low calorific value (LCV) fuel gas with heating values (HHV) ranging from 1.88 to 4.64 MJ/m3n (50 to 120 Btu/scf). In the current paper the experiments are presented where the amount of primary and secondary air are varied in order to examine the effects of stoichiometry on the combustors performance and these results are compared with a previously tested downscaled typhoon combustor from ALSTOM. Also, results are presented with respect to traversing measurements behind the primary zone of the TUD combustor. It was found that the NH3 to NO conversion decreases at increasing pressure and that higher concentrations of methane in the fuel result in higher ammonia to NO conversions. Also it was observed that the swirling typhoon combustor seemed to have less problems achieving lower ammonia conversions than the bluff body stabilized TUD combustor.

Measurements Inside a Bluff-Body Stabilized Gas Turbine Combustor for Application of Pressurized Biomass Derived Low Calorific Value Fuel Gas and Comparison of the Results

2005 ◽  
Author(s):  
Marco van der Wel ◽  
Wiebren de Jong ◽  
Hartmut Spliethoff
Keyword(s):  
Gas Turbine ◽  
Bluff Body ◽  
Calorific Value ◽  
Medium Size ◽  
Wood Pellets ◽  
Gas Turbine Combustor ◽  
Fuel Gas ◽  
Miscanthus Giganteus ◽  
Primary Zone ◽  
Comparison Of The Results

A medium size gas turbine combustor of 1.5 MW of Delft University (TUD) has been tested to combust low calorific value (LCV) fuel gas. The LCV gas was obtained from pressurized gasification of wood pellets class A, miscanthus giganteus and brown coal and was cleaned from its particulates by high temperature ceramic filters of β-cordierite. Stable combustion of (biomass derived) low calorific value fuel gas with heating values (LHV) between 1.64 and 4.48 MJ/m3n (50 to 120 Btu/scf) was accomplished due to high fuel gas temperatures ranging from 845 to 1099 K. Main species (O2, CO2,) and minor species (Ar, CH4, H2, CO, NO) were measured in the exhaust and by a traversing probe after the primary zone of the combustor. The water and nitrogen contents in the exhaust were calculated from the element balances. The results are compared with a previously tested combustor of ALSTOM Power of the RQL type.

Gas Turbine Combined Cycle With CO2-Capture Using Auto-Thermal Reforming of Natural Gas

2000 ◽  
Author(s):  
Thormod Andersen ◽  
Hanne M. Kvamsdal ◽  
Olav Bolland
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Process Integration ◽  
Combined Cycle ◽  
Co2 Removal ◽  
Gas Turbine Combustor ◽  
Chemical Absorption ◽  
Fuel Gas ◽  
The Impact ◽  
Water Gas

A concept for capturing and sequestering CO2 from a natural gas fired combined cycle power plant is presented. The present approach is to decarbonise the fuel prior to combustion by reforming natural gas, producing a hydrogen-rich fuel. The reforming process consists of an air-blown pressurised auto-thermal reformer that produces a gas containing H2, CO and a small fraction of CH4 as combustible components. The gas is then led through a water gas shift reactor, where the equilibrium of CO and H2O is shifted towards CO2 and H2. The CO2 is then captured from the resulting gas by chemical absorption. The gas turbine of this system is then fed with a fuel gas containing approximately 50% H2. In order to achieve acceptable level of fuel-to-electricity conversion efficiency, this kind of process is attractive because of the possibility of process integration between the combined cycle and the reforming process. A comparison is made between a “standard” combined cycle and the current process with CO2-removal. This study also comprise an investigation of using a lower pressure level in the reforming section than in the gas turbine combustor and the impact of reduced steam/carbon ratio in the main reformer. The impact on gas turbine operation because of massive air bleed and the use of a hydrogen rich fuel is discussed.

scholarly journals The Development of a Diesel Burning Combustion Chamber With a Multiple Jet Primary Zone

1987 ◽  
Author(s):  
R. V. Cottington ◽  
J. P. D. Hakluytt ◽  
J. R. Tilston
Keyword(s):  
Gas Turbine ◽  
Shear Layers ◽  
Fuel Quality ◽  
Carbon Formation ◽  
Gas Turbine Combustor ◽  
Smoke Emission ◽  
Primary Zone ◽  
Efficient Combustion ◽  
Operational Range ◽  
Lean Conditions

A new primary zone for a gas turbine combustor has been developed which achieves efficient combustion in fuel lean conditions for minimizing carbon formation. This uses a large number of jets in the head of the chamber to generate independent shear layers in a co-operative array. Good combustion performance, wide fuel/air ratio operational range and tolerance to fuel quality have been demonstrated on research rigs. The combustor itself has been developed to an engine standard for a naval gas turbine required to operate with low smoke emission on distillate diesel fuel. The rig programme used to optimise the design is described together with results from engine evaluation. Practical advantages of this type of chamber apply equally to aero applications on kerosene.

Towards Improved Prediction of Aero-Engine Combustor Performance Using Large Eddy Simulations

2008 ◽  
Author(s):  
S. James ◽  
M. S. Anand ◽  
B. Sekar
Keyword(s):  
Gas Turbine ◽  
Radial Profile ◽  
Design Tool ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Gas Turbine Combustor ◽  
Systematic Assessment ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Aero Engine

The paper presents an assessment of large eddy simulation (LES) and conventional Reynolds averaged methods (RANS) for predicting aero-engine gas turbine combustor performance. The performance characteristic that is examined in detail is the radial burner outlet temperature (BOT) or fuel-air ratio profile. Several different combustor configurations, with variations in airflows, geometries, hole patterns and operating conditions are analyzed with both LES and RANS methods. It is seen that LES consistently produces a better match to radial profile as compared to RANS. To assess the predictive capability of LES as a design tool, pretest predictions of radial profile for a combustor configuration are also presented. Overall, the work presented indicates that LES is a more accurate tool and can be used with confidence to guide combustor design. This work is the first systematic assessment of LES versus RANS on industry-relevant aero-engine gas turbine combustors.

Development of a Dual-Fuel Gas Turbine Engine of Liquid and Low-Calorific Gas

2005 ◽  
Author(s):  
Masamichi Koyama ◽  
Hiroshi Fujiwara
Keyword(s):  
Gas Turbine ◽  
Sewage Treatment ◽  
Energy Resource ◽  
Biomass Energy ◽  
Dual Fuel ◽  
Fuel Gas ◽  
Turbine Engine ◽  
Reference Velocity ◽  
Continuous Use ◽  
Wasted Energy

We developed a dual-fuel single can combustor for the Niigata Gas Turbine (NGT2BC), which was developed as a continuous-duty gas turbine capable of burning both kerosene and digester gas. The output of the NGT2BC is 920 kW for continuous use with digester gas and 1375 kW for emergency use with liquid fuel. Digester gas, obtained from sludge processing at sewage treatment plants, is a biomass energy resource whose use reduces CO2 emissions and take advantage of an otherwise wasted energy source. Design features for good combustion with digester gas include optimized the good matching of gas injection and swirl air and reduced reference velocity. The optimal combination of these parameters was determined through CFD analysis and atmospheric rig testing.

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