scholarly journals Gas and Liquid Fuel Injection Into an Enclosed Swirling Flow

1984 ◽  
Author(s):  
N. T. Ahmad ◽  
G. E. Andrews
Keyword(s):  
Liquid Fuel ◽  
Fuel Injection ◽  
Swirling Flow ◽  
Combustion Efficiency ◽  
Swirl Flow ◽  
Liquid Fuels ◽  
Recirculation Region ◽  
Liquid Droplets ◽  
The Stability ◽  
Stability Limits

A swirler with good premixed performance has been tested with direct central propane injection and with direct central kerosene and gas oil injection using the swirler air for atomisation. The results have been compared with non swirling flow systems at the same test conditions. Direct propane injection results in a major extension of the stability limits compared with the premixed situation, but with liquid fuel injection the stability limits are generally worse than for premixed fuel and air. It is argued that the cause of this is the action of the centrifugal forces on the liquid droplets in the swirl flow which results in vaporisation in the outer swirl flow and weaker mixtures in the core recirculation region than for propane injection. The gas composition results support this conclusion. Direct propane injection caused a deterioration in the combustion efficiency and a large increase in NOx. The poor stability limits with liquid fuels prevented a high combustion efficiency and low NOx situation from being achieved. A comparison of the performance with non swirling systems showed that all emissions were higher with swirl for propane but that the swirler may have some advantages for liquid fuels.

Development and Integration of the Dual Fuel Combustion System for the MGT Gas Turbine Family

2021 ◽  
Author(s):  
Bernhard Ćosić ◽  
Frank Reiss ◽  
Marc Blümer ◽  
Christian Frekers ◽  
Franklin Genin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Distribution System ◽  
Gas Turbines ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Liquid Fuels ◽  
Dual Fuel ◽  
Gaseous Fuels ◽  
Supply And Distribution ◽  
Industrial Gas Turbines

Abstract Industrial gas turbines like the MGT6000 are often operated as power supply or as mechanical drives. In these applications, liquid fuels like 'Diesel Fuel No.2' can be used either as main fuel or as backup fuel if natural gas is not reliably available. The MAN Gas Turbines (MGT) operate with the Advanced Can Combustion (ACC) system, which is capable of ultra-low NOx emissions for gaseous fuels. This system has been further developed to provide dry dual fuel capability. In the present paper, we describe the design and detailed experimental validation process of the liquid fuel injection, and its integration into the gas turbine package. A central lance with an integrated two-stage nozzle is employed as a liquid pilot stage, enabling ignition and start-up of the engine on liquid fuel only. The pilot stage is continuously operated, whereas the bulk of the liquid fuel is injected through the premixed combustor stage. The premixed stage comprises a set of four decentralized nozzles based on fluidic oscillator atomizers, wherein atomization of the liquid fuel is achieved through self-induced oscillations. We present results illustrating the spray, hydrodynamic, and emission performance of the injectors. Extensive testing of the burner at atmospheric and full load high-pressure conditions has been performed, before verification within full engine tests. We show the design of the fuel supply and distribution system. Finally, we discuss the integration of the dual fuel system into the standard gas turbine package of the MGT6000.

Investigation of Reverse Flow Slinger Combustor with Jet A-1 and Methanol

2021 ◽  
Author(s):  
Abhishek Dubey ◽  
Pooja Nema ◽  
Abhijit Kushari
Keyword(s):  
Fuel Injection ◽  
Reverse Flow ◽  
Lightweight Design ◽  
Injection Pressure ◽  
Combustion Efficiency ◽  
Flame Stabilization ◽  
Liquid Fuels ◽  
Flame Stability ◽  
Lean Blowout ◽  
Lean Fuel

Abstract This paper describes experimental investigation of a Reverse Flow Slinger (RFS) combustor that has been developed in order to attain high flame stability and low emissions in gas turbine engines. The combustor employs centrifugal fuel injection through a rotary atomizer and performs flame stabilization at the stagnation zone generated by reverse flow configuration. The design facilitates entrainment of hot product gases and internal preheating of the inlet air which enhances flame stability and permits stable lean operation for low NOx. Moreover, the use of rotary atomizer eliminates the need for high injection pressure resulting in a compact and lightweight design. Atmospheric pressure combustion was performed with liquid fuels, Jet A-1 and Methanol at ultra-lean fuel air ratios (FAR) with thermal intensity of 28 - 50 MW/m3atm. Combustor performance was evaluated by analyzing the lean blowout, emissions and combustion efficiency. Test results showed high flame stability of combustor and a very low lean blowout corresponding to global equivalence ratio of around 0.1 was obtained. Sustained and stable combustion at low heat release was attained and NOx emissions as low as of 0.4 g/Kg and 0.1 g/Kg were obtained with Jet A-1 and Methanol respectively. Combustion efficiency of 55% and 90% was obtained in operation with Jet A-1 and Methanol. Performance of the combustor was significantly better with Methanol in terms of emissions and efficiency.

Experimental Study on Lean Blowout Limits of Turbulent Premixed Hydrogen/Ammonia/Air Mixtures

2021 ◽  
Author(s):  
Andreas Goldmann ◽  
Friedrich Dinkelacker
Keyword(s):  
Gas Turbines ◽  
Measurement Procedure ◽  
Liquid Fuels ◽  
Special Focus ◽  
Atmospheric Conditions ◽  
Ammonia Content ◽  
Lean Blowout ◽  
Combustion Properties ◽  
The Stability ◽  
Stability Limits

Abstract As the demand for greenhouse gas neutral transportation and power generation solutions is growing, alternative carbon-free fuel such as hydrogen (H2) and ammonia (NH3) are gaining more attention. Mixtures of both fuels allow the adjustment of combustion properties. With future fuels also the vision of very clean combustion can be taken into the focus, being for instance based on lean premixed and for liquid fuels prevaporized combustion for gas turbines. For the utilization of such concepts, however, flame stability is essential. In this study the upper stability limits, i.e. lean blowout of turbulent hydrogen/ammonia/air flames, is experimentally investigated in a generic non-swirl premixed burner at atmospheric conditions. Special focus is laid on a measurement setup with fully automatized measurement procedure, to reach the stability limits, as these limits tend to depend for instance on the approach speed towards the limit. The ammonia content was varied from 0 vol% to 50 vol% in 10 vol% steps with the rest being hydrogen, for a broad range of fuel-air-equivalence ratios. The lean blowout limit is increasing almost linearly with increasing fuel-air-equivalence ratios, whereas with increasing ammonia content the limit is decreasing. Furthermore, a model for the lean blowout limits were derived, which is able to predict the acquired experimental data with high accuracy.

Further Studies of Alternative Jet Fuels

2009 ◽  
Author(s):  
Christopher J. Mordaunt ◽  
Seong-Young Lee ◽  
Vickey B. Kalaskar ◽  
Amy Mensch ◽  
Robert J. Santoro ◽  
...  
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Combustion Instability ◽  
Combustion Efficiency ◽  
Liquid Fuels ◽  
Pollutant Emission ◽  
Fischer Tropsch ◽  
Mixing Processes

Future gas turbine technology may require that liquid fuels play an additional role as a coolant over a wide range of combustion-chamber operating conditions. Additionally, in order to satisfy greater efficiency and performance goals, gas turbine operating temperatures and pressures are steadily increasing. Given the desire to reduce dependence on foreign fuels and that current hydrocarbon fuels, such as JP-8, are prone to thermal or catalytic decomposition at such elevated conditions, there is great interest in utilizing alternatively-derived liquid fuels. The successful development of a versatile, multiple-use fuel must achieve the desired operational characteristics of high combustion efficiency, excellent combustion stability, acceptable pollutant emission levels, and compatibility with current engine seals. Combustion instability represents a critical area of concern for future gas turbine engines that may burn alternative fuels. Combustion instability is characterized by large, unsteady combustion-chamber pressure oscillations which occur at the characteristic frequencies associated with the acoustic modes of the combustor. The occurrence of combustion-driven instabilities is closely tied to the details of the injection and fuel-air mixing processes, the heat release characteristics, and the degree to which heat release rate couples with the acoustics of the combustor. Additionally, the efficiency and emissions characteristics are also largely determined by the fuel injection, atomization, and mixing processes associated with combustion. As fuel properties and composition vary, effects on combustion efficiency and emissions, especially the formation of nitrogen oxides (NOx) and soot, can be expected. Therefore, changes in these processes attributed to differing fuel properties can have a dramatic affect on the combustion characteristics and require careful consideration through a well-coordinated combustion research program. The current study investigates whether a coal-based aviation fuel, JP-900, which has the required thermal stability attributes, also satisfies the engine combustion requirements. Additionally, a Fischer-Tropsch fuel and a volumetric 50/50 blend of JP-8 and the Fischer-Tropsch fuel are studied. Previous studies of coal-based fuels have shown that soot production can be a significant problem due to the higher aromatic content than found in conventional fuels. However, improvements in the fuel refinement processes have helped reduce this problem. Experiments included in this current research effort involve studying the combustion instability patterns, the pollutant emission levels, and sooting propensity of coal-based and Fischer-Tropsch fuels as compared to JP-8. The experimental setup consists of an optically-accessible model gas turbine dump combustor, with provisions for laser extinction measurements, which utilizes a Delavan hollow-cone pressure atomizer for fuel injection.

scholarly journals Experimental research of liquid-fueled continuously rotating detonation chamber

Shock Waves ◽  
2021 ◽  
Author(s):  
P. Wolański ◽  
W. Balicki ◽  
W. Perkowski ◽  
A. Bilar
Keyword(s):  
Liquid Fuel ◽  
Fuel Injection ◽  
Liquid Fuels ◽  
Turbine Engines ◽  
Practical Application ◽  
Propulsion Systems ◽  
Hot Air ◽  
Mixture Preparation ◽  
The Rich ◽  
Rotating Detonation

AbstractResearch on the application of liquid fuels to continuously rotating detonation was conducted. A new method of mixture preparation was proposed. A special system of liquid fuel injection was designed and tested which is based on injecting into the detonation chamber a preheated liquid fuel partially mixed with hot air at conditions higher than the rich flammability limit. The specially selected conditions allow all liquid fuel to evaporate in the supply system but prevent it from ignition before entering the detonation chamber. Experiments were conducted for two different liquid fuels, extraction gasoline and Jet-A fuel. Research was carried out for different equivalence ratios, and in all tested conditions detonation was achieved. The new tested method of liquid fuel preparation and injection into a cylindrical detonation chamber opens a way of application of liquid fuels to engines which utilize continuously rotating detonation and thus prepares the way for practical application of detonative combustion to turbine engines and jet propulsion systems.

Conical Grid Plate Flame Stabilizers: Stability and Emissions for Liquid Fuels

1986 ◽  
Author(s):  
A. F. Ali ◽  
G. E. Andrews
Keyword(s):  
Mach Number ◽  
Fuel Injection ◽  
Combustion Efficiency ◽  
Liquid Fuels ◽  
Injection System ◽  
Flame Stability ◽  
Gas Oil ◽  
Air Jets ◽  
Primary Zone ◽  
Grid Plate

Flame Stability and Emission results are presented for a jet shear layer primary zone design consisting of a 90° conical flame stabiliser with a central annular vaporiser fuel injection system feeding an array of air jets. The performance with kerosene and gas oil fuels is compared with previous work with propane. The influence of the primary zone residence time or Mach number is shown to be much more significant for liquid fuels than for propane. An acceptable combustion efficiency was only achieved at a Mach number of 0.03, corresponding to 60% of the combustion air in the primary zone, provided that the pressure loss was maintained as the Mach number was reduced by using a stabiliser of higher blockage. NOx emissions with kerosene were compatible with those for propane, but for gas oil there was a significant increase in NOx.

scholarly journals Ultra Low NOx Emissions for Gas and Liquid Fuels Using Radial Swirlers

1989 ◽  
Author(s):  
H. S. Alkabie ◽  
G. E. Andrews
Keyword(s):  
Gas Turbines ◽  
Fuel Injection ◽  
Air Flow ◽  
Combustion Efficiency ◽  
Liquid Fuels ◽  
Inlet Temperature ◽  
Flame Stability ◽  
Nox Emissions ◽  
Gas Oil ◽  
Industrial Gas Turbines

Curved blade radial swirlers using all the primary air were investigated with applications to lean burning gas turbine combustor primary zones with low NOx emissions. Two modes of fuel injection were compared, central and radial swirler pássage injection for gaseous and liquid fuels. Both fuel systems produced low NOx emissions but the upstream mixing in the swirler passages resulted in ultra low NOx emissions. A 140mm diameter atmospheric pressure combustor was used with 43% of the combustor air flow into the primary zone through the radial swirler. Radial gas composition measurements at various axial distances were made and these showed that the flame stability and NOx emissions were controlled by differences in local mixing at the base of the swirling shear layer downstream of the swirler outlet. For radial passage fuel injection it was found that a very high combustion efficiency was obtained for both propane and liquid fuels at 400K and 600K inlet temperatures. The flame stability, although worse than for central fuel injection was considerably better than for a premixed system. The NOx emissions at one bar pressure and 600K inlet temperature, compatible with a high combustion efficiency, for propane and kerosene were 3 and 6 ppm at 15% oxygen. For Gas Oil the NOx emissions were higher, but were still very low at 12ppm. Assuming a square root dependence of NOx on pressure these results indicate that NOx emissions of 48ppm for Gas Oil and less than 12ppm for gaseous fuels could be achieved at 16 bar pressure, which is typical of recent industrial gas turbines. High air flow radial swirlers with passage fuel injection have the potential for a dry solution to the NOx emissions regulations.

Lean Low NOx Primary Zones Using Radial Swirlers

1988 ◽  
Author(s):  
H. S. Alkabie ◽  
G. E. Andrews ◽  
N. T. Ahmad
Keyword(s):  
Natural Gas ◽  
Recirculation Zone ◽  
Fuel Injection ◽  
Swirling Flow ◽  
Combustion Efficiency ◽  
Flame Stability ◽  
Nox Emissions ◽  
Primary Zone ◽  
Outer Expansion ◽  
Curved Blade

Swirling flow primary zones with between 30% and 60% simulated primary zone air flow were investigated using curved blade radial swirlers. Two radial swirlers were compared with the same open area but different outlet diameters, d, giving different expansion ratios, D/d, from the swirler to the combustor diameter, D. Two combustors were used, 76 mm and 140 mm diameter, the larger one corresponding to the size of several gas turbine can combustors. There was no influence of D/d on the weak extinction. It was demonstrated that an adequate efficiency was not achieved in the weak region until there was a significant outer expansion and associated recirculation zone. It was shown that these systems with central gaseous fuel injection had good flame stability with very low NOx emissions. Propane and natural gas were compared and the NOx emissions were 50% lower with natural gas. The optimum NOx emissions, compatible with a high combustion efficiency, were close to 10 ppm NOx emissions corrected to 15% oxygen.

scholarly journals Mixing and Fuel Atomisation Effects on Premixed Combustion Performance

1983 ◽  
Author(s):  
G. E. Andrews ◽  
M. M. Abdul Aziz ◽  
N. A. Al-Dabbagh
Keyword(s):  
Liquid Fuel ◽  
Fuel Injection ◽  
Constant Pressure ◽  
Combustion Efficiency ◽  
Premixed Combustion ◽  
Flame Stability ◽  
Nox Emissions ◽  
Jet Mixing ◽  
Mixing Effects ◽  
Single Droplets

The main objective was to compare a flame stabiliser at constant pressure loss and identical isothermal aerodynamics with three modes of fuel injection: premixed, direct propane injection and direct kerosene injection. A Jet Mixing type of flame stabiliser was used at simulated gas turbine primary conditions. The influence of gaseous mixing effects was to deteriorate the combustion efficiency solely by increasing the CO emissions and to increase the NOx emissions. The flame stability was increased and low CO emissions were achieved at weaker mixtures. Liquid fuel atomisation effects resulted in a further deterioration in combustion efficiency due solely to un-burnt hydrocarbons. However, the NOx emissions were reduced indicating that local stoichiometric burning around single droplets does not occur.

Experimental Analysis on the Formation of CO-NO-HC in Swirling Flow Combustion Chamber

2015 ◽  
Vol 72 (4) ◽  
Author(s):  
Mohamad Shaiful Ashrul Ishak ◽  
Mohammad Nazri Mohd. Jaafar ◽  
Wan Zaidi Wan Omar
Keyword(s):  
Combustion Chamber ◽  
Swirling Flow ◽  
Swirl Flow ◽  
Recirculation Region ◽  
Mixing Rate ◽  
Swirl Angle ◽  
Low Emission ◽  
Air Mixing ◽  
Efficient Combustion ◽  
Hc Emissions

The main purpose of this paper is to evaluate the production of CO-NO-HC emissions while varying the swirl angle of curve vane radial swirler. Swirling flow generates central recirculation region (CRZ) which is necessary for flame stability and enhances fuel air mixing. Therefore designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion inside burner system. Four radial curved vane swirlers with 30o, 40o, 50o and 60o vane angles corresponding to swirl numbers of 0.366, 0.630, 0.978 and 1.427 respectively were used in this experiment to measure the vane angles effect on emission production in the combustion chamber. Emission measurements were conducted at 5 axial distances from the burner throat, and at 5 locations along the radius starting the central axis at each section. It was found that at the core near the throat, CO and HC concentrations are low due to high available O2 and high fuel mixing rate producing efficient combustion. This is due to the high shear region created the high swirl flow.

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