The method of adjusting the distribution of air flow
(57) Abstract:The method can be used in the engine, namely in combustion chambers of gas turbine engines. At maximum load the hydraulic resistance of the mixing chamber air-fuel mixture is reduced due to the supply of jet fuel to the air flow direction, and with a minimum of strain respectively increases due to the supply of jet fuel against the direction of air flow. The technical result is increased reliability of the method of adjusting the distribution of air flow in the combustion chamber. 4 Il. , 1 table. The invention relates to the field of engine construction and can be used in combustion chambers of gas turbine engines.A known method of regulating the distribution of air flow, in which the quantity of air entering the primary zone of the combustion chamber is regulated mode external fan connected to the power source, forcing air to the burner depending on the load of the gas turbine, with the aim of supporting all loads of the gas turbine of the mixture in the combustion zone provides low levels of emissions of harmful substances the e-fan works by forcing air into the primary combustion zone and low system reliability regulation, contains moving parts in the flow part of the combustion chamber.A known method of regulating the distribution of air flow on the primary and secondary combustion chambers with variable geometry, in which the regulation is effected by the axial movement of the stabilizer, changing the flow area of the front of the device, depending on the load of the gas turbine engine .The disadvantage of this method is the low reliability of the design because it requires the introduction of the Executive transmitting mechanism regulating effect (electrical or mechanical) to the stabilizer of the combustion chamber.Closest to the invention is a method of regulating the distribution of air flow along the contours of the combustion chamber (primary combustion zone, the zone of mixing with the combustion products), in which regulation is carried out by changing a pass square channel pipeline to channel a portion of the compressed air leaving the compressor to the burner . In the pipeline is installed valve that changes the flow area of the pipeline. In the run mode the valve is installed in the position of minimum opening and the minimum quantity of air is agrusti the amount of air entering the primary zone is increased by opening the valve. The control system regulates the opening of the valve depending on the temperature before the turbine and the load of the turbine, which support the specified range of ratios of excess air and temperature in the primary combustion zone. Controlling these parameters reach reduce emissions of carbon monoxide, oxides of nitrogen and unburned hydrocarbons by maintaining the composition of the fuel-air mixture in the combustion zone provides low levels of emissions of harmful substances.The disadvantage of this method is the low reliability of the design since there are moving parts in the flow part of the combustion chamber.The problem to which the invention is directed, is to increase the reliability of the method of adjusting the distribution of air flow in the combustion chamber by eliminating moving parts in the flow part of the combustion chamber.This object is achieved in that in the method of regulating the distribution of air flow which consists in changing the hydraulic resistance of the air path of the front device, the combustion chamber depending on the load of the gas turbine in contrast to the known prototype p is by applying jets of fuel in the air flow direction, and with minimal strain respectively increases due to the supply of jet fuel against the direction of air flow. Thus the use of the described method allows to operate the burner in a narrow range of composition of the mixture in the combustion zone is regulated environmental requirements and ensures the reliability of the method of regulation.In Fig. 1 shows the results of calculations and experimental data on emissions of the burner operating conditions HPA GTK-10I.In Fig. 2 shows a diagram of a combustion chamber in which is described the way.In Fig. 3 depicts a graph of a program controlling the flow of air in the working conditions HPA GTK-10I.In Fig. 4 shows a diagram of the experimental setup.The method is carried out in the combustion chamber, containing in the front of the device, one or more burners with preliminary preparation of the fuel-air mixture in the mixer which must contain two injector for supplying gaseous fuel with the United independent fuel systems, through a single injector, the fuel is fed in the direction of air flow, and black the systems by using a fuel injection valve, heating pipe with holes for supplying dilution air with the hydraulic resistance that would be when fuel is in the direction of the air flow at maximum mode operation of a gas turbine coefficient of excess air in the primary combustion zone corresponded to the lowest possible excess air coefficient. The fuel flow valve must meet the following requirement: it is necessary to increase the hydraulic resistance of the line supplying air-fuel mixture when the load of the gas turbine engine and its decrease with increasing load, and maximum load all fuel must be supplied in the direction of the air flow, and a gradual transition to the fuel against the forward air flow should be in the case of lowering of the load when the level of emission of carbon monoxide begins to exceed the regulated environmental requirements level.An example of a specific application of the method.Consider the combustion chamber of the pumping unit GPA GTK-10I.Working conditions of the combustion chamber:
the temperature at the inlet into the combustion chamber (Tin) - 543 K
Amer combustion (P) - 0.7 MPa
In the serial the combustion chamber of the aggregate emission levels of nitrogen oxides exceed environmental standards (NOx= 232 mg/m315% O2), because used in this design concept fuel combustion in diffusion mode. Modernization of the combustion chamber is in the installation of burners with pre-mix fuel, for example, a burner from .A burner with axial swirler and pre-mix fuel consists of two tubes one inside the other, in the annular channel of the supplied air, the inner tube is supplied with gaseous fuel mixed with air in the annular channel.The fuel supply is carried out from the holes located along and against the direction of air flow and placed on pylons on the outer surface of the inner pipe, respectively.Swirling the expanding fuel-air flow at the outlet of the burner creates a stable zone of reverse currents for a slice of the inner tube, which ensures the stability of the combustion of pre-mixed fuel air mixture of a poor composition.The control system its required fuel flow along and against the direction of air flow in the burner devices, similar in design and used a regulated supply duty fuel into the combustion chamber with the preliminary preparation of the fuel-air mixture poor composition. The fuel system also includes two rows of fuel pylons for supplying gaseous fuel along and against the flow direction of air (Fig. 2).The programme of work of the regulatory system for gas turbine plants HPA GTK-10I. When the total air excess factor from 3,74 to 5.2 is the supply of gaseous fuel in the direction of the air flow, when the total air excess factor from 5.2 to 5,57 part of the fuel is fed against the direction of flow, when the total air excess factor above 5,57 all the fuel is fed against the direction of flow.Current analysis shows that the use of this method of controlling the flow of air in the zone of preliminary preparation of the mixture depending on the degree of load of the unit provides an opportunity to ensure that environmental requirements for emissions of CO and NOxon the modes from 60% to 100% of maximum load.The concentration of nitrogen oxides does not exceed at > 1,5 (coefficient of excess air in the primary zone) levels, limited ACDs optimal distribution of air flow over the length of the combustion chamber at maximum load unit SCC-10I (Fig. 1., the flow in the combustion zone is 43% of the total air flow through the combustion chamber).Taking into account features of the business cycle gas turbine unit (GTU) unit SCC-10, you can make that work, shoot from the free turbine (payload) equal to thermal effect combustion of the fuel depends on the fuel consumption, and hence inversely proportional To the maximum mode, the coefficient of excess air for the whole combustion chamber = 3,74, taking into account the fact that in the primary zone receives 43% of the air on the mode 65% of the maximum coefficient of excess air in the primary zone will be equal to = 2,451 and as shown in Fig. 1. levels of carbon monoxide emissions for this mode in the absence of regulatory systems will be inflated.The calculation of the change of hydraulic resistance in the above-described method of controlling the amount of air entering the primary zone was based on the well-known method proposed by G. N. Abramovich .The system of equations includes:
the mass conservation law in the form
G3= G1+ G2< / BR>the law of conservation of energy
< / BR>the law of conservation of momentum
G3w3+ p3F3= G1p- specific heat at constant pressure, T-temperature, w is the velocity, p is the pressure, F is the area of the orifice.Using the known gas-dynamic functions q () z() and the speed ratio of the above equations can be reduced to the dimensionless form:
< / BR>< / BR>< / BR>where
n = G2/G1;
< / BR>R is the gas constant;
k is the adiabatic exponent, the index "*" corresponds to the locked thread.From the resulting system of equations, knowing the parameters of the flow at the inlet in the mixing device, it is possible to determine the flow parameters at the exit of the mixer, including the loss of total pressure in the mixing device p*= p*1-p*3:
< / BR>where the index p denotes the parameters in the primary zone, the index of the parameters of the secondary air flow, index options at the entrance to the combustion chamber, - density, - - hydraulic resistance, referred to the output of the square element.The range of operation of the burner is defined below the minimum to the questions of nitrogen oxides and top - maximum air excess factorCRwhere else are the environmental requirements for emissions of carbon monoxide. The excess air coefficient is a function of the costs of air and gas in the burner device.The results of the calculations for this system of equations at T1= 543 K, T2= 288 K= 6,p= 2, P= 0.7 MPa,PR u= 2,min= 1,45 shown in Fig. 3.Experimental data for comparison with the calculations shown in the table. The constructive scheme of the experimental setup is shown in Fig. 4.Thus the proposed method can increase the reliability of the method of adjusting the distribution of air flow.The sources of information.1. U.S. patent N 4992040, CL F 23 D 14/02, 1985.2. Canelo P. M. the Toxicity of the CCD and the prospects for the use of hydrogen. Kiev, Nauk. Dumka, 1982, 140 S.3. International application WO 94/00718, CL F 23 R 3/34, 3/36, F 23 D 17/00, F 23 D 14/26, 1990.4. Russian Federation patent RU 2036383 C1, class F 23 D 14/02, 1995.5. Abramovich, N. Applied gas dynamics. M., Nauka. CH. nat. Ed. - Mat. lit., 1991, 600 S. The method of adjusting the distribution of air flow, which in change is t load of the gas turbine, characterized in that at maximum load the hydraulic resistance of the mixing chamber air-fuel mixture is reduced due to the supply of jet fuel to the air flow direction, and with a minimum of strain respectively increases due to the supply of jet fuel against the direction of air flow.
FIELD: fuel combustion device for gas-turbine engines.
SUBSTANCE: proposed device has case, as well as fixed and movable flow separators wherein fuel is supplied to flame-stabilizing fuel manifolds built of fixed and movable parts and provided with coaxial holes. Movable sleeve is inserted in movable part of stabilizing manifold. Holes are disposed in movable part of stabilizing manifold and in sleeve at right angle to stabilizing manifold axis, and in fixed part holes have their sectional area contracting toward outlet. Springs are installed between movable part of stabilizing manifold and sleeve.
EFFECT: enhanced operating efficiency of combustion chamber throughout entire operating range of engine.
1 cl, 5 dwg
FIELD: gas turbine engine engineering.
SUBSTANCE: combustion chamber comprises housing provided with inner and outer ring shells, device for graduate change of the ratio of areas of the cross-sections of primary and secondary passages, and collector stabilizer. The reaction zone has shutters and inserts that define inner and outer rings. The shutters and inserts are pivotally interconnected for permitting change of the area of the cross-section in radial direction. The collector stabilizer is unmovable.
EFFECT: enhanced reliability.
FIELD: engines and pumps.
SUBSTANCE: device to control a low emission combustion chamber of a gas turbine, specifically of gas turbine assemblies, comprises case with channels supplying primary and secondary air into a flame tube of the combustion chamber and with a channel for mixing basic fuel with primary air, wherein this channel an axial swirler and synchronous adjustment devices to control consumption of primary and secondary air are installed. The devices of synchronous adjustment of consumption of primary and secondary air are installed in corresponding channels of the case and interconnected with each other so that at an increase or decrease of primary air consumption correspondently causes an increase or decrease of secondary air consumption. An initial portion of the flame tube is made as an intake diffuser. A device to control consumption of primary air is made as a flame stabilizer and installed with a possibility to axial displacement in intake diffuser of the flame tube; at that it is connected to the regulator of basic fuel to maintain ratio of surplus air in the primary air supply channel and in the mixing channel constant or close to constant within ranges from 1.7 to 2.5. The blades of the axial swirler are arranged concentric at an angle to its axis bigger or equal to 30°. A nozzle with a critical section is installed at the outlet from the combustion chamber.
EFFECT: device allows to extend the range of stable operation and adjustment of a combustion chamber, to reduce a possibility of self excited oscillation of pressure in a combustion chamber and to reduce harmful exhaust.
4 cl, 1 dwg
FIELD: engines and pumps.
SUBSTANCE: gas turbine combustion chamber contains a casing with an annular flame tube incorporating two spaced apart annular shells jointed together by the front wall streamwise first part, the said wall being furnished with heat-insulating screens arranged on the combustion space side. The said heat-insulating screens contain flanges and ribs on the side facing the front wall provided with the holes for the burner modules to be installed therein and for cooling air to pass through. The rib and flange, on every heat-insulating screen, are enclosed along the outline. The heat-insulating screen surface with the rib and the front wall form a space communicating, via the burner module holes, with the flame tube space. The flanges of adjacent heat-insulating screens together with the front walls form flowing channels. The front wall cooling air passage holes are arranged along the outline of every heat-insulating screen on both sides of a rub. The flange side facing the combustion space continues the screen surface.
EFFECT: low power engine, complete fuel combustion and reliable combustion chamber.
3 cl, 3 dwg
SUBSTANCE: invention related to energy, particularly to burner devices and can be used in gas turbine equipment. Burner device consists of a case (1), a fuel nozzle (2), a front device (3), a fire tube (4). The burner device belongs to gas-turbine engine combustion chamber. The front device executed with holes for fuel nozzles installation (2). The fire tube (4) with the front device (3) located inside of the combustion chamber cage (5). Fuel nozzles (2) connected to a gas ring collector (6). In combustion chamber fire tube and cage (5) between wall area air nozzles (7) located radically. Air nozzles (7) connected to the common ring air collector (9). The air collector (9) located in the case (1).
EFFECT: invention allows to regulate primary air supply to the combustion chamber section during equipment operation, burning device design simplification, it operation safety stays constant, possibility of device change on the running gas turbine equipment.
FIELD: power industry.
SUBSTANCE: combustion chamber includes housing, flame tube with air supply holes to combustion and mixing zones, and front device with air swirlers and fuel feed atomisers. Flame tube of combustion chamber has geometrical and gas-dynamic criteria providing its optimum operating mode. Ratio of cross midlength section area to total effective surface area of all holes is 7.0 ±1.5. Relative carrying capacity of swirlers is 0.17 ±0.1. Air flow swirling intensity with swirlers of front device is 0.8±0.4, and flow velocity coefficient in flame tube holes is 0.22±0.1.
EFFECT: invention provides maximum economy, reliability and service life of engine.
FIELD: engines and pumps.
SUBSTANCE: diffusion chamber of gas turbine engine is arranged between external case and internal case of engine, supplied with air through inlet diffusion channel and includes combustion chamber of convergent type. Combustion chamber restricts external annular channel with external case and internal annular channel with internal case. Diffusion chamber includes the fairing partially covering external annular channel. Fairing includes the housing made in the form of round part formed with rotation about fairing axis. Housing is located between two planes which are essentially transverse to the above axis of fairing and has plane section. Also, the housing includes radial external end and radial internal end. Fairing includes external side starting from the above radial external end and radial internal side starting from radial internal end, as well as fasteners intended for its fixture on combustion chamber. The other objects of this invention is combustion chamber located in the above diffusion chamber, as well as gas turbine engine containing such diffusion chamber.
EFFECT: invention allows reducing pressure losses.
14 cl, 10 dwg
FIELD: engines and pumps.
SUBSTANCE: proposed combustion chamber comprises housing, fire pipe with combustion and dilution zones, fuel feed system, primary and secondary air flows feed system. The latter comprises the device to act on secondary air flow inside circular channel between combustion chamber and fire pipe walls. Besides, it includes fuel-air mix ignition device. Said device to act on secondary air flow inside circular channel comprises laser radiation source, optical fibre and at least two opposed mirrors arranged inside said channel. One of said mirrors has through bore at focal line. Laser radiation source can excite molecular oxygen to singlet state and is connected via optical fibre with through bore of the mirror.
EFFECT: ruled out carbon monoxide, almost completely, from engine exhaust gases, more complete fuel combustion.
10 cl, 2 dwg
FIELD: engines and pumps.
SUBSTANCE: proposed combustion chamber comprises housing accommodating the perforated fire tube with combustion and dilution zones, fuel feed system, air primary and secondary flow feed system and fuel-air mix ignition system. Airflow feed system incorporates primary airflow controller in primary air channel and secondary airflow controller inside circular channel between combustion chamber walls and fire tube. Said controllers include laser radiation source, laser radiation splitter for primary and secondary airflows controllers. Every said controller incorporates optic fibres with inputs connected to laser radiation splitter. Output of primary airflow controller optic fibre is connected via through hole with primary airflow inlet channel equipped with at least two opposed mirrors. Secondary airflow controller comprises at least two opposed mirrors located inside circular channel, one of the mirrors having a through hole at mirror axis in focal plane. Output of secondary airflow controller optic fibre is connected via mirror through hole with circular channel. Laser source can excite oxygen molecules to metastable singlet states.
EFFECT: higher completeness of combustion and chamber efficiency.
16 cl, 3 dwg
FIELD: engines and pumps.
SUBSTANCE: device to burn fuel in a gas turbine engine comprises outer and inner bodies forming a circular cavity, where fixed and mobile flow separators are installed, forming alternating primary and secondary channels. On the outer body of the circular cavity in each primary channel there are symmetrical rectangular cuts corresponding to its size, with fixed flow separators passing through them. In the end part of the circular cavity there are two rings installed as capable of rotation around the longitudinal axis, the diameter of one of which corresponds to the diameter of the outer body, of the second one - the diameter of the inner body. On the outer ring there are 2N slots, where N - natural even number corresponding to the number of primary channels. In each primary channel there are two plates installed, being made according to the profile of the wing and hingedly fixed on the inner ring, with the possibility of displacement along the longitudinal axis of the engine along the slots on the outer ring and around their central axis. The slot length corresponds to plate travel from minimum to maximum size of the primary channel. In each primary channel there are angular flame stabilisers installed with an opening angle of 55-65 degrees in direction of the flow, which are rigidly fixed on the outer and inner rings as equidistant along the circumference. The point of fixation on the outer ring is between the slots of the appropriate channel.
EFFECT: invention is aimed at expansion of the range of combustion chamber stable operation.