Disadvantage of annular combustion chamber

This invention relates generally to gas turbine engines and, more particularly, to combustion systems relating thereto. The invention herein described was made in the course of or under a contract, or a subcontract thereunder, with the United States Department of the Air Force. Recent efforts to reduce emissions in gas turbine engines have brought about the use of staged combustion techniques wherein one burner or set of burners is used for low speed, low temperature conditions such as idle, and another, or additional, burner or burners are used for higher temperature operating conditions.

One particular configuration of such a concept is that of the double annular combustor wherein the two stages are located concentrically in a single combustor liner. It will be recognized by one skilled in the art that in a double annular combustor, where the height of the dome is always greater than that of the turbine nozzle annulus, the outer section is going to be generally straight and of short length, and the inner section is going to be generally curved and have a longer length.

It has been recognized that these structural relationships are disadvantageous for a number of reasons. In regard to emissions, when the engine is operating at idle, the pilot stage is operating with low compressor discharge temperatures and pressures and the reaction rates are thus relatively slow.

Accordingly, in order to allow for complete or near-complete combustion to thereby reduce the amount of hydrocarbon and carbon monoxide emissions, it is preferable to have a long residence time, a characteristic which is not inherent in the shorter radially outside pilot section.

On the other hand, in the main stage section, where nitrous oxides are the primary emission problem, it is desirable to minimize the residence time so as to also minimize the forming of nitrous oxides.

Again, locating of the main stage section on the radially inner side tends to defeat this purpose since this section is necessarily longer than that on the outer side. Another disadvantage of having the main burner on the radially inner side is that the higher temperature gases emanating from that burner tend to flow against the curved inner liner of the combustor.

Thus, it is necessary to provide a high degree of cooling to that liner in order to prevent it from burning through. A further condition which renders the conventional double annular combustor configuration inadequate is that of the resulting natural profile at the turbine nozzle annulus.

Ideally, in order to optimize turbine life, it is desirable to have a profile in which the temperatures are cooler at the inner diameter than at the outer diameter.

However, with the main burner located radially inward as described hereinabove, the profile which exists is one having hotter temperatures toward the turbine inner side. It is therefore an object of the present invention to provide a double annular combustor with reduced emission operating characteristics.

Another object of the present invention is the provision of a double annular combustor with improved structural integrity. Yet another object of the present invention is the provision in a double annular combustor for minimizing the impingement of hot gases against the liner of the combustor.

Still another object of the present invention is the provision in a double annular combustor for a turbine inlet temperature profile which is cooler on the radially inner side.

Yet another object of the present invention is the provision of a double annular combustor which is economical to manufacture and efficient and effective in use.

turbo-annular combustion chamber

These objects and other features and advantages become more readily apparent upon reference to the following description when taken in conjunction with the appended drawings.

Briefly, in accordance with one aspect of the invention, the relative positions of the pilot and main stage sections of a conventional double annular combustor are reversed, that is the pilot stage is placed in the radially inner portion of the combustor and the main stage section is placed in the radially outer portion thereof.

In this way, the effective length of the main stage section is relatively short and the effective length of the pilot stage section is relatively long. Further, the profile of the main stage is straightened so that the hot gases do not impinge against the combustor liner, but, rather, it is the low temperature gases from the pilot stage which impinge against the inner liner of the combustor.

Finally, the resulting temperature profile at the turbine inlet exhibits higher temperatures toward the radially outer side. By another aspect of the invention, an igniter is introduced into the pilot stage section by a tube which projects through the combustor outer casing and extends radially inward to the inner dome.

This tube may be either straight or curved and have ceramic insulators placed between the igniter leads and the outer tube. In the drawings as hereinafter described, a preferred embodiment and modified embodiments are depicted; however, various other modifications and alternate constructions can be made thereto without departing from the true spirit and scope of the invention. Referring to the drawings, and particularly to FIG.

The hollow body 12 is generally annular in form and is comprised of an outer liner 14 and an inner liner At the upstream end of the hollow body 12 is an annular opening 17 for the introduction of air and fuel in a preferred manner as will be described hereinafter.

disadvantage of annular combustion chamber

The hollow body 12 may be enclosed by a suitable shell 19 which, together with the liners 14 and 16, defines passages 21 and 22, respectively, which are adapted to deliver in a downstream flow the pressurized air from a suitable source such as a compressor not shown and a diffuser The compressed air from the diffuser 23 passes principally into the annular opening 17 to support combustion and partially to the passages 21 and 22 where it is used to cool the liners 14 and 16 by way of a plurality of apertures 24 and to cool the turbomachinery further downstream.Why don't fictional characters say "goodbye" when they hang up a phone?

If we can't tunnel through the Earth, how do we know what's at its center? All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply. Hottest Questions. Previously Viewed. Unanswered Questions. Needs a Topic. What are the advantages of multiple can combustion chamber?

Wiki User Cheap to produce. A combustion chamber refers to the part of an engine in which fuel is burned. The pressure in a combustion chamber reaches up to bar. Asked in Combustion Engines How does a combustion chamber work? A combustion chamber refers to a machine or engine where fuel is burnt. For example, many steam engine trains have a combustion chamber where coal is burnt. Diesel Engine combustion chamber types : Swirl port combustion chamber type and Preignition port combustion chamber type.

Asked in Science What is the reason for having a combustion chamber on a rocket? A combustion chamber is where combustion occurs in a controlled fashion. Because the basic idea of a rocket is burning fuels and directing them in the opposite direction to that of travel, a controlled burning - as happens in the combustion chamber - is exactly what a rocket needs to work.

From the combustion of air and fuel in the combustion chamber. Asked in Chevy What is the intake and exhaust valve purpous? After combustion, the spent gasses travel out of the combustion chamber through the exhaust valve. The compression ratio of an internal-combustion engine, or an IC engine as it is more commonly called, is the ratio of the volume the highest capacity of the combustion chamber to its lowest capacity. In the IC engine, the piston makes a stroke, resulting in the compression of the air in the combustion chamber - the ratio between the volume of the cylinder and combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke, is the compression ratio.

Hemispherical combustion chamber. Temperature inside the diesel engine combustion chamber is approximately degree Centigrade Celsius.

Asked in Technology What is humming in gas turbine? The formation of combustion oscillations can occur during an operation of a gas turbine burner.Why don't fictional characters say "goodbye" when they hang up a phone? If we can't tunnel through the Earth, how do we know what's at its center?

All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply. Hottest Questions. Previously Viewed. Unanswered Questions. Needs a Topic. What is the disadvantage for can annular type combustion chamber? We need you to answer this question! If you know the answer to this question, please register to join our limited beta program and start the conversation right now!

Related Questions Asked in Mechanical Engineering How many types of combustion chambers are in a gas turbine? Asked in Science, Combustion Engines How many types of combustion chambers are used in gas turbines? Diesel Engine combustion chamber types : Swirl port combustion chamber type and Preignition port combustion chamber type.

Domed pistons would be typically found in a hemispherical combustion chamber. Asked in Home Improvement, Heating Ventilating and Air Conditioning, Fireplaces What is another term for the combustion chamber in a furnace or fireplace? Type your answer here Asked in Combustion Engines Which type of engine is classified as internal combustion?

Reciprocating engines piston engines are internal combustion engines. Rotary engines Wankel engine is also an internal combustion engine. In general, all types of engines in which the combustion chamber is an integrating part of the engine is considered a internal combustion engine.SUBSTANCE: proposed annular combustion chamber of gas-turbine engine contains annular space formed by casing, fire tube with head unit, burning zone and mixing zone, fuel feed system and igniter.

Annular space and front part of each head of head unit are sealed. Fuel feed system is made to deliver water into space of casing and deliver mixture of water solution of electrolyte and fuel through nozzle and cavitator into each head of head unit. Igniter is made in form of arc electrodes. Electrodes are installed in each head of head unit for striking and extinction of arc, and dissociation, ionization, ignition and turning into plasma vapors of mixture passing through arc burning zone.

One of electrodes is movable at striking of arc and other electrode is made conical and provided with conical channel. The invention relates to engine, in particular to the combustion chambers, and can be used in gas turbine engines for various purposes. Known combustion chamber air-jet engine, comprising a housing, a cavity which has the flame tube with a combustion zone, a mixing zone, injector fuel supply and igniter device. A disadvantage of the known combustion chamber is on the expensive fuel and emissions.

Closest to the proposed invention is an annular combustor of a gas turbine engine containing an annular cavity formed by the casing, a heating pipe unit heads in the front part of the combustion zone, a mixing zone, the fuel supply system and the igniter device.

Aviation gas turbine engines. The disadvantage of the combustion chamber analogue is its low economic and ecological efficiency. The technical problem solved by the invention is to improve the economic and environmental efficiency of the combustion chamber of a gas turbine engine. The problem is solved in that the annular combustion chamber g is surbinovo engine containing kolicevo cavity formed by the casing, a heating pipe with a head block, a combustion zone and mixing zone, the fuel supply system and the igniter device.

The annular cavity and the front part of each head of the head Assembly is airtight. While one of the electrodes may be made movable, for example, performed a controlled solenoid valve with ignition volt arc, the other may be made conical and tapered channel. Annular combustion chamber of a gas turbine engine includes an annular cavity 1 formed by the casing 2 and, for example, is sealed by the lid 3, the annular flame tube 4 with the mixing zone 5 and sealed the front part of each head 6 head block.

While one of the electrodes is made movable - movable solenoid valve 13 when the ignition volt arc, the other is made conical and tapered to the cash The flame tube in the casing secured cups 15, its thermal expansion occurs in the direction of the turbine Annular combustion chamber of a gas turbine engine operates as follows. Before starting the work on the electrodes 9 and 10 volt arc elektroizolyatsionnyh from the body bushings and spacer 12, serves adjustable, for example, the control unit DC current from the vehicle electrical system, for example, force A.

Include electromagnetic valve 13 and intermittent contact with the end of the movable electrode 9 with the electrode conical form 10, in its tapered channel 14, kindle volt arc. Due to cavitation in the cavitator nozzle 8 part supplied to the mixture to dissociate, ionize and all the mixture of fine atomized into steam, due to the cooling elements of the cylinder head heads and cone-beam channel 14 flows into the combustion zone 11 volt arc.

Under the influence of burning volt arc and due to the flow of direct current through the electrolyte mixture to dissociate, ionize, ignite into a plasma under a pressure of and the m and the plasma temperature of the combustion zone 11 volt arc cone in the channel 14 of the electrode 10 is fed into the mixing zone 5 of the annular flame tube 4.

In a sealed annular cavity 1 casing 2 through the nozzle 7 under pressure atmospheres and under the control of the control unit serves and sprayed, for example, himochishchennuju water that cools the annular flame tube 4, it turns into water vapor and then enters the annular mixing zone 5. In the mixing zone 5 combustion products plasma and water vapor coming from the cavity 1, are mixed, the temperature of the plasma normalized to an acceptable value and then is supplied to the turbine While the flame tube 4 in the casing 2 is attached cups 15, its thermal expansion occurs in the direction of the turbine.

The electrodes 9 and 10 are cooled by passing through them, and wrapping them with water vapor. To extinguish volt arc cut off the supply of DC current to the electrodes 9 and 10 and stop the flow of water and the mixture of electrolyte and fuel into the combustion chamber. Offer annular combustor of a gas turbine engine in operation safe, highly efficient and environmentally friendly. Will find application in gas turbine engines for various purposes.

The combustion chamber according to claim 1, wherein one of the electrodes is made movable in the volt ignition of the arc, the other is made of conical shape and the tapered channel. SUBSTANCE: proposed tubular-annular combustion chamber of gas-turbine engine has annular space formed by casing which accommodates fire tubes with burning zone and mixing zone, fuel feed system and igniter. Annular space and front part of each fire tube are made hermetically sealed.The combustion section contains the combustion chambers, igniter plugs, and fuel nozzle or fuel injectors.

It is designed to burn a fuel-air mixture and to deliver combusted gases to the turbine at a temperature not exceeding the allowable limit at the turbine inlet. Theoretically, the compressor delivers percent of its air by volume to the combustion chamber. However, the fuel-air mixture has a ratio of l5 parts air to 1 part fuel by weight. Approximately 25 percent of this air is used to attain the desired fuel-air ratio.

This ensures that the turbine section will not be destroyed by excessive heat. The air used for burning is known as primary air; that used for cording is secondary air. Secondary air is controlled and directed by holes and louvers in the combustion chamber liner.

disadvantage of annular combustion chamber

Igniter plugs function during starting only; they are shut off manually or automatically. Combustion is continuous and self-supporting.

annular combustion chamber

After engine shutdown or failure to start, a pressure-actuated valve automatically drains any remaining unburned fuel from the combustion chamber. The most common type used in Army gas turbine engines is the external annular reverse-flow type. The primary function of the combustion section is, of course, to bum the fuel-air mixture, thereby adding heat energy to the air. To do this efficiently, the combustion chamber must —.

The location of the combustion section is directly between the compressor and turbine sections. The combustion chambers are always arranged coaxially with the compressor and turbine, regardless of type, since the chambers must be in a through-flow position to function efficiently. The can-type combustion chamber is typical of the type used on both centrifugal and axial-flow engines Figure 1. It is particularly well suited for the centrifugal compressor engine since the air leaving the compressor is already divided into equal portions as it leaves the diffuser vanes.

It is then a simple matter to duct the air from the diffuser into the respective combustion chambers arranged radially around the axis of the engine.

disadvantage of annular combustion chamber

The number of chambers will vary; in the past as few as 2 and as many as 16 chamber's have been used. The present trend is about 8 or 10 combustion chambers.

Figure 1 illustrates the arrangement of can-type combustion chambers. On American-built engines these chambers are numbered in a clockwise direction facing the rear of the engine with the No. Each can-type combustion chamber consists of an outer case or housing with a perforated stainless steel highly heat-resistant combustion chamber liner or inner liner Figure 2.

The outer case is divided for ease of liner replacement. The larger section or chamber body encases the liner at the exit end; the Smaller chamber cover encases the front or inlet end of the liner.

The interconnector flame propagation tubes area necessary part of can-type combustion chambers. Since each can is a separate burner operating independently of the others, there must be some way to spread combustion during the initial starting operation. This is done by interconnecting all the chambers. The flame is started by the spark igniter plugs in two of the lower chambers; it passes through the tubes and ignites the combustible mixture in the adjacent chamber.Application: The gas turbine is used where high power and speed are main consideration.

Gas turbine is used in jet population unit in air craft, in ships as population unit, in supercharging system in automobile and also in electric generating station and in locomotives.

The open cycle turbine is mainly used in airplanes. Today we have discussed about gas turbine types, advantages and disadvantages, working and application. If you have doubt regarding gas turbine, ask by commenting. Subscribe our website for more informative articles. Thanks for reading it. Your email address will not be published. Skip to content. September 11, February 13, Admin 2 Comments power plant engineeringTurbine. Sharing is Caring :. Today we will learn about types, advantages and disadvantages, application and working of gas turbine.

There are different gas turbines which used in different conditions. Gas turbine is mainly used air as the working fluid. The air is taken from atmosphere and compressed into a compressor. The compressed air is passed through combustion chamber where it is heated. Due to continuously heating in combustion chamber, pressure and temperature of air increases. This high pressure hot air allow to flow over the moving blades of turbine, which rotate the turbine. Finally the air is exhausted into the atmosphere.

This is the main process of gas turbine. The power developed by the gas turbine is used for rotate the compressor and for doing some external work. Gas Turbines:. The gas turbine may be classified as follow.

US4194358A - Double annular combustor configuration - Google Patents

According to the path of the working substance:. Closed cycle gas turbine. It is the simplest form of gas turbine, which consist a compressor, combustion chamber, gas turbine and a cooling chamber. This turbine is worked on Brayton cycle.Mentioned in? References in periodicals archive? The test case of spray combustion in this paper is a typical single-head annular combustion chamber model, which is shown in Figure 6.

The combustion chamber of the aviation gas turbine, along with the injection system, initially designed for kerosene, were geometrically adjusted, the annular combustion chamberwell known, was next divided in eight identical slices, corresponding to the injectors number, for reducing the necessary time and calculating resources. Emission level calculation for water injection in gas turbines. A comparison of the temperature and pressure field obtained by the Adiabatic Chemical Equflibrium and the Generalized Finite Rate models, to simulate a twin-spool gas turbine's annular combustion chamberis presented in this paper.

Efecto del modelo de combustion en la prediccion del campo de temperatura y presion de una camara anular. The engine is actually an extremely modular 36 MW unit with a high efficiency power turbine and gas generator that exploit advances in blade cooling concepts this helps achieve 42 per cent thermal efficiencyand an annular combustion chamber configured to reduce emissions.

Medium-sized ship's steam. Encyclopedia browser? Full browser?


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