CN106051827B - A kind of 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable and method of work - Google Patents

Abstract

The invention discloses an array-adjustable nine-point lean direct injection (LDI) clean combustion chamber and a working method thereof, comprising an air inlet, an assembly seat, an observation window, a combustion cavity, a nine-point array injection structure, an axial Cyclone, Venturi and other structures. The air enters the combustion chamber from the intake port, passes through the axial swirler to generate a high-speed swirl, and the fuel is directly injected into the combustion chamber from the nozzle, and each nozzle is inserted into the corresponding axial swirler, and the fuel is in the Venturi Under the action of the high-speed swirling flow generated by the pipe and the outlet of the swirler, it is atomized and crushed, and the air and fuel are mixed in the combustion chamber while igniting and burning. The equivalent ratio of the injected fuel is less than 1, which means lean combustion. The clean combustion chamber structure of the present invention can realize the conversion of various swirler head arrays without additional processing of any swirlers or parts, and proposes two new head arrays to further develop the nine points Low emission potential of LDI combustors.

Description

An array-adjustable nine-point lean fuel direct injection cleans the combustion chamber and its working method

technical field

The invention relates to an array-adjustable nine-point lean direct injection (LDI) clean combustion chamber and a working method, belonging to the field of clean combustion of gas turbine engine combustion chambers.

Background technique

With the increasing air pollution, countries and international organizations around the world have made clear regulations on the emission standards of various power plants. With the introduction of environmental protection laws and regulations, the pollutant emission standards of gas turbine engines have become increasingly stringent. For example, in the field of civil aviation, the International Civil Aviation Organization (International Civil Aviation Organization, ICAO) promulgated the first emission standard CAEP1 in 1986, and revised the fifth emission standard CAEP8 in 2010. Only from the development of this field, we can see It is precisely these increasingly stringent emission standards that promote the continuous development and improvement of clean combustion technology.

With the gradual deepening of researchers' understanding of the influence of factors such as combustion temperature, residence time, gas mixture composition, and oil-gas state on gas turbine engine pollutant emissions, the development of partitioned staged combustion, lean premixed pre-evaporation (Lean Premixed Prevaporized, LPP for short) combustion, Rich-Quench-Lean (RQL for short) combustion, Lean Direct Injection (LDI for short) combustion, Lean Direct Mix (LDM for short) ) and a large number of clean combustion technologies such as double-annular cavity premixing technology.

Lean direct injection (LDI) combustion technology is to inject fuel directly into the combustion zone in a lean manner, and quickly mix with air to form a uniform combustible mixture for ignition and combustion, because the lean direct injection (LDI) combustion chamber is to inject fuel It is directly injected into the main combustion area and mixed with air for combustion without premixing and pre-evaporation process, thus solving the problem of backfire and spontaneous combustion in LPP combustion technology, and the lean oil-gas ratio reduces the flame temperature of the main combustion area and reduces NO _X emissions, while the uniform combustible mixture eliminates local hot spots, and can also reduce NO _X emissions.

The concept of multi-point LDI was first proposed by Tacina R and applied to the clean combustion chamber of aero-engines. It was gradually developed and established under the High Speed Research program proposed by NASA in the 1990s. Its realization method is simply described Come, it is by uniformly arraying multiple fuel nozzles on the head, each fuel nozzle has an axial swirler and a shrinking Venturi tube, the fuel nozzle directly injects fuel into the combustion zone, and the air passes through the swirler to generate The high-speed swirling flow forms a recirculation zone at the head of the combustion zone to ensure combustion. The air entering the combustion zone and the fuel are mixed quickly after contact to form a uniform air mixture and complete combustion. The potential of lean combustion in low pollution and direct injection in Advantages in avoiding problems such as flashback, spontaneous combustion, etc., while achieving clean burning and reliable operation. The basic structure head of the nine-point lean direct injection (LDI) combustor contains nine swirler venturi tubes in a 3x3 array, which can be divided into two arrays according to the different swirl directions of adjacent swirlers , that is, the same direction and reverse structure, when all the cyclones have the same direction of rotation, it is called the same direction structure, and the structure where two adjacent cyclones rotate in the opposite direction is called the reverse structure.

The present invention designs a nine-point lean direct injection (LDI) clean combustion chamber with adjustable arrays, which can realize the switching of four swirler head arrays without additional processing of any swirlers or parts; at the same time, Based on the flow shear direction of the swirl interaction area at the outlet of adjacent cyclones, two new nine-point head arrays are designed. The present invention can be applied to the field of gas turbine clean combustion, such as industrial power generation, urban heating, civil aeroengine and other fields, to promote advanced clean combustion technology, reduce the pollution of gas turbine engine emissions to the environment, especially for nine-point LDI combustion In the study of the chamber, the use of the array-adjustable combustion chamber structure can simplify the assembly and disassembly process of the swirler head and reduce the cost of additional processing. Through the study of the new head swirler array method, the nine points can be further developed Low emission potential of LDI combustors.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the problem to be solved by the present invention is to design two new cyclone arrays based on the direction in which the swirls at the outlets of adjacent cyclones shear each other. In order to realize the conversion of head swirler arrays, an array-adjustable nine-point lean direct injection (LDI) cleaning combustor and working method are designed to realize switching between four swirler arrays.

Technical scheme: in order to achieve the above object, the technical scheme adopted in the present invention is:

An array-adjustable nine-point lean direct injection cleaning combustion chamber, including an intake port and a combustion chamber connected through an assembly seat, wherein the end of the intake port is provided with a nine-point array injection structure;

The inner end of the assembly seat is provided with a swirler-venturi tube corresponding to the nozzles of the nine-point array injection structure; the swirler-venturi tube is composed of an axial swirler and a venturi tube. Connecting the combined structures formed sequentially, the venturi tube is connected to the combustion cavity;

The nozzles of the nine-point array injection structure are connected with nozzles, and the ends of the nozzles are inserted into the axial swirler of the swirler-venturi tube.

Further, the assembly seat is a semi-closed hollow structure with an open front end, and a cyclone installation hole is provided at the end, corresponding to the nozzles of the nine-point array injection structure; the nozzles are drawn from the nine-point array The front section of the assembly seat is inserted into the cyclone installation hole, and each cyclone installation hole is inserted into a cyclone-venturi tube from the other side, and the nozzle goes deep into the cyclone-venturi tube The throat, the fuel enters the combustion chamber through the swirler-venturi tube.

Further, there is a groove on the top of the nine-point array injection structure, and the front end of the assembly seat includes a boss and a step, and the step matches the outer dimension of the nine-point array injection structure to carry out peripheral Positioning in the direction; the groove cooperates with the boss for axial positioning.

Further, the cyclone-venturi tube has two bosses: a front boss and a rear boss, and the contact position between the assembly seat and the cyclone-venturi tube is provided with two stepped grooves : a front groove and a rear groove; wherein the front groove is matched with the front boss correspondingly, and the rear boss is matched with the rear groove correspondingly to position the cyclone-venturi tube.

Further, the assembly seat is connected with the intake port and the combustion chamber through flanges to form an array of adjustable nine-point lean oil direct injection cleaning combustion chambers, and gaskets are placed between the flanges. The gasket ensures airtightness.

Further, an observation window is provided at the front end of the combustion cavity.

Further, the end of the assembly base is provided with a swirler head baffle, and the swirler-venturi tube is correspondingly snapped into the upper opening and fixed. The cyclone-venturi is fixed by the cyclone head baffle.

A working method for cleaning a combustion chamber with an array-adjustable nine-point lean fuel direct injection, comprising the following steps:

1) The air enters the combustion chamber from the air inlet, and generates high-speed swirl when passing through the axial swirler;

2) The fuel enters from the nine-point array injection structure, and is directly injected into the combustion cavity through the venturi tube (7) through the nozzle inserted into the corresponding axial swirler; The combination of different rotation directions of the blades forms different forms of head arrays;

3) In step 2), the fuel is atomized and broken under the action of the high-speed swirl generated by the venturi tube and the outlet of the axial swirler, and the air and fuel are ignited and burned while mixing in the combustion chamber. A fuel equivalence ratio of less than 1 means lean combustion.

Further, in the step 2), through the combination of different rotation directions of the blades of the axial swirler, the formation of different forms of head arrays includes:

① The flow of fluid in the interaction area between adjacent axial swirlers is in the same direction;

②The flow of fluid in the interaction area between adjacent axial swirlers is reversed;

③The direction of flow in the area between any two interacting axial swirlers is all the same;

④The directions of flow in the area between any two interacting axial swirlers are all opposite.

The invention relates to an array-adjustable nine-point lean direct injection (LDI) clean combustion chamber and a method thereof, which belong to the field of clean combustion of gas turbine engine combustion chambers. Array adjustable nine-point lean direct injection (LDI) clean combustion chamber mainly includes intake port, assembly seat, observation window, combustion cavity, nine-point array injection structure, axial swirler, venturi tube and other structures . The air enters the combustion chamber from the intake port, passes through the axial swirler to generate a high-speed swirl, and the fuel is directly injected into the combustion chamber from the nozzle, and each nozzle is inserted into the corresponding axial swirler, and the fuel is in the Venturi Under the action of the high-speed swirling flow generated by the pipe and the outlet of the swirler, it is atomized and crushed, and the air and fuel are mixed in the combustion chamber while igniting and burning. The equivalent ratio of the injected fuel is less than 1, which means lean combustion. The present invention designs a nine-point Lean Direct Injection (LDI) clean combustion chamber structure with an adjustable array, which can realize the conversion of various swirler head arrays without additional processing of any swirlers or parts. And proposed two new head array ways. The present invention can be applied to the field of gas turbine clean combustion, such as industrial power generation, urban heating, civil aeroengine and other fields, to promote advanced clean combustion technology, reduce the pollution of gas turbine engine emissions to the environment, especially for nine-point LDI combustion In the study of the chamber, the use of the array-adjustable combustion chamber structure can simplify the assembly and disassembly process of the swirler head and reduce the cost of additional processing. Through the study of the new head swirler array method, the nine points can be further developed Low emission potential of LDI combustors.

Beneficial effects: the array-adjustable nine-point lean direct injection (LDI) cleaning combustion chamber and method thereof provided by the present invention have the following advantages compared with the prior art:

1. The array-adjustable nine-point Lean Direct Injection (LDI) clean combustion chamber has a simple structure, simple processing technology and assembly, mainly including the intake port, assembly seat, observation window, combustion chamber, and nine-point array injection structure , Axial swirler, Venturi tube, its key structural mounting seat can realize the assembly and disassembly of the head swirler, and can be flexibly converted between the four head swirler arrays without additional processing of the swirler or other Parts provide great convenience for engineering application assembly.

2. The new array of two head swirlers enriches the combination of the direction of action of adjacent swirlers. The new head array has a head flow field structure that is different from the existing two arrays. It is worthy of further study. Research, in order to more thoroughly study and understand the complex reasons for the formation of the head flow field structure.

Description of drawings

Figure 1 is a half-sectional view of the structure of the nine-point lean direct injection clean combustion chamber with adjustable array;

Fig. 2 is an assembly schematic diagram of the assembly seat structure of the nine-point lean fuel direct injection cleaning combustion chamber with adjustable array;

Fig. 3 is a half-sectional view of the structure of the nine-point lean fuel direct injection cleaning combustion chamber assembly seat with adjustable array;

Fig. 4 is a schematic diagram of the array method of cleaning the head of the combustor with nine-point lean fuel direct injection with adjustable array.

In the figure: 1 intake port, 2 assembly seat, 3 observation window, 4 combustion cavity, 5 nine-point array injection structure, 6 axial swirler, 7 venturi tube, 8 swirler installation hole, 9 swirl Venturi tube, 10 cyclone head baffle, 11 nozzle, 12 groove, 13 boss, 14 step, 15 front boss, 16 rear boss, 17 front groove, 18 rear groove, 19 method Lan, 20 swirl directions are the same, and 21 swirl directions are opposite.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

The scheme of the array-adjustable nine-point lean oil direct injection cleaning combustion chamber and its method adopted in the present invention is: according to the same or opposite direction of swirl flow at the junction of adjacent swirler outlet swirl flow, it can be divided into flow in the same direction or flow in the same direction. For reverse flow, considering the central symmetry of the nine-point cyclone, the swirl direction of the cyclone at the symmetrical position is consistent with the outlet flow direction, and two new cyclone arrays are designed, as shown in Figure 4 CASE3 and CASE4.

The flow in the head of the nine-point lean direct injection (LDI) clean combustion chamber is very complicated, and the combination of different swirler swirl directions will produce different head flow field structures due to strong interactions. In the existing public research results , nine-point Lean Direct Injection (LDI) cleans the combustion chamber head Each swirler outlet fluid will generate strong turbulence, forming a weak backflow zone, but due to the interaction between adjacent swirler heads, this backflow The zone cannot expand further near the head. If the nine-point head array method is divided into three levels: A, B, and C, there is interaction between A and B, and interaction between B and C. In the two array methods of CASE1 and CASE2 that can be seen in the public results , the direction of flow in the region between any two interacting cyclones is all the same or all opposite. The head flow fields of these two arrays have the same characteristics and have their own characteristics: the same direction array, each outlet The swirl flow will gradually merge into a large swirl flow and rotate along the original direction, but it cannot form a large reverse pressure gradient to generate a recirculation zone. The reverse array method will not be able to merge due to the opposite direction of adjacent swirl flows, and each maintains The direction of its own swirl flow continues to expand, but its swirl degree attenuation will be greater than that of the same direction swirl flow, but neither of these two array methods can produce a central recirculation zone. And two kinds of new array modes CASE3 and CASE4 that the present invention proposes, the relative flow direction of fluid in the boundary region between A and B is opposite to the relative flow direction of fluid between B and C stages, so the head produced The flow field will also have new features.

Figure 1 shows a half-sectional view of the structure of a multi-point LDI combustion chamber. The combustion chamber mainly includes an air inlet 1, an assembly seat 2, an observation window 3, a combustion chamber 4, a nine-point array injection structure 5, and an axial swirl flow. Device 6, venturi tube 7. The air enters the combustion chamber from the air inlet 1, passes through the axial swirler 6 to generate a high-speed swirl, and the fuel is directly injected into the combustion chamber 3 from the nozzle 11. The nozzle is a centrifugal nozzle, and adopts a nine-point array. The nozzles 11 are all inserted into the corresponding axial swirler 6, the fuel is atomized and broken under the action of the high-speed swirl generated by the venturi tube 7 and the swirler outlet, and the air and fuel are mixed in the combustion chamber 4 Ignition and combustion are carried out, and the injected fuel equivalence ratio is less than 1, which means lean combustion.

Fig. 2 is an assembly schematic diagram of the structure of the assembly seat 2 of the multi-point LDI combustion chamber. Figure 3 The nozzle 11 is inserted into the swirler installation hole 8 on the assembly seat 2 from the direction of the front air inlet 1 of the assembly seat 2 in a nine-point array, and each installation hole 8 is inserted into a swirler from the other side - Venturi The position where the pipe 9 and the nozzle 11 go deep into the venturi tube is the throat of the venturi tube, and the fuel oil just enters the combustion chamber 4 from the venturi tube. The cyclone-venturi tube 9 is fixed by the cyclone head baffle 10, and the baffle 10 presses the venturi tube-cyclone 9 tightly. When the test piece needs to change the combustor head array, it only needs to take off the swirler head baffle 10 and replace the corresponding swirler.

Figure 3 is a half-sectional view of the structure of the multi-point LDI combustion chamber assembly seat. There is a groove 12 on the top of the nine-point array injection structure 5. The front end of the assembly seat includes a boss 13 and a step 14. The step 14 is connected to the nine-point injection structure 5 The outer dimensions match to realize circumferential positioning, and the groove 12 cooperates with the boss 13 to realize axial positioning. The position where the nozzle 11 goes deep into the venturi tube is the throat of the venturi tube, and the fuel can just enter the combustion chamber 4 from the venturi tube. The cyclone-venturi tube 9 has two bosses: a front boss 15 and a rear boss 16, and the assembly seat 2 has two stepped grooves: a front groove 17 and a rear groove 18. Among them, the front groove 17 and the front boss 15 correspond to the positioning of the swirler-venturi tube 9, the rear boss 16 and the rear groove 18 cooperate with the positioning of the swirler-venturi tube 9, and the baffle 10 presses the venturi tube-the swirl The device 9 is axially positioned by the rear groove 18. The realization of axial positioning means that there is a step on the rear boss 16 and a groove on the rear groove 18. The plane corresponding to the step and the groove can realize positioning in one direction, and put the baffle plate 10 into the assembly seat 2 in the other direction. The corresponding groove can be fixed with bolts to realize positioning. The assembly seat 2 is connected with the air inlet 1 and the combustion chamber 4 through the flange 19, and a gasket is placed between the flanges 19 to ensure airtightness.

Fig. 4 is a schematic diagram of the multi-point LDI combustor head array mode, where CASE1 and CASE2 are two array modes existing in published documents, and CASE3 and CASE4 are two array modes proposed by the present invention for the first time. 20 and 21 in the figure respectively indicate that the flow of fluid in the interaction area between adjacent swirlers is in the same direction and in the opposite direction. Note that the same direction and the reverse direction here do not indicate the swirl direction of the swirl flow, but only in the In this interaction position, whether the fluids all flow from bottom to top (or from top to bottom) or flow in opposite directions.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (8)

1. a kind of 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable, it is characterised in that：Including passing through assembling stand（2）Group Close the air intake duct of connection（1）And burning cavity（4）, wherein, the air intake duct（1）End be provided with nine lattice array spray structures （5）；

The assembling stand（2）Interior end is provided with and the nine lattice arrays spray structure（5）The one-to-one cyclone of spout- Venturi tube（9）；Cyclone-the Venturi tube（9）For by axial swirler（6）And Venturi tube（7）It is sequentially connected formed group Close structure, the Venturi tube（7）It is communicated to the burning cavity（4）In；

The nine lattice arrays spray structure（5）Spout be connected with nozzle（11）, the nozzle（11）End be inserted into the rotation Flow device-Venturi tube（9）Axial swirler（6）In；

The assembling stand（2）For the semiclosed hollow structure of front opening, end sets cyclone mounting hole（8）, with described nine Lattice array spray structure（5）Spout correspond；The nozzle（11）From the assembling stand in a manner of nine lattice arrays（2）Before Section is inserted into the cyclone mounting hole（8）In, each cyclone mounting hole（8）From opposite side be inserted into a cyclone- Venturi tube（9）, the nozzle（11）Go deep into the cyclone-Venturi tube（9）Venturi, fuel oil is via the cyclone-Wen Pipe（9）Into the burning cavity（4）.

2. 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable according to claim 1, it is characterised in that：It is described Nine lattice array spray structures（5）Top have a groove（12）, the assembling stand（2）Front end include boss（13）And step （14）, the step（14）With the nine lattice arrays spray structure（5）Contour dimension cooperation, carry out it is circumferentially positioned；It is described recessed Slot（12）With the boss（13）Cooperation carries out axially position.

3. 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable according to claim 1, it is characterised in that：It is described Cyclone-Venturi tube（9）There are two boss for band：Front boss（15）And rear boss（16）, the assembling stand（2）With the eddy flow Device-Venturi tube（9）Contact position set there are two stepped groove：Preceding slot（17）And pit（18）；Wherein described preceding slot（17）With it is preceding Boss（15）Corresponding matching, the rear boss（16）And pit（18）Corresponding matching positions cyclone-Venturi tube（9）.

4. 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable according to claim 1, it is characterised in that：It is described Assembling stand（2）Pass through flange（19）Same air intake duct（1）And burning cavity（4）9 points of oil-poor direct sprays of connection composition array adjustable Penetrate cleaning combustion chamber, the flange（19）Between put gasket.

5. 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable according to claim 1, it is characterised in that：It is described Burning cavity（4）Front end position be equipped with observation window（3）.

6. 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable according to claim 1, it is characterised in that：It is described Assembling stand（2）End be provided with cyclone baffle head（10）, the cyclone-Venturi tube（9）Correspondence is caught in perforate thereon Middle fixation.

7. a kind of method of work of 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable, it is characterised in that：Including following Step：

1）Air is by air intake duct（1）Into burning cavity（4）, by generating high-speed rotational during axial swirler；

2）Fuel is from nine lattice array spray structures（5）Into via being inserted into corresponding axial swirler（6）In nozzle （11）, pass through Venturi tube（7）It is directly injected to burning cavity（4）In；Pass through the axial swirler（6）Blade different rotary The combination in direction, the head array mode being variously formulated；

3）Step 2）In, fuel oil is in Venturi tube（7）And axial swirler（6）Be atomized under the action of the high-speed rotational that outlet generates, Broken, air is with fuel oil in burning cavity（4）Middle that ignition is carried out in mixing, the fuel oil equivalent proportion of penetrating is less than 1, is Poor oil firing.

8. the method for work of 9 points of oil-poor directly injection cleaning combustion chambers of array adjustable according to claim 7, special Sign is：The step 2）In, pass through the axial swirler（6）Blade different rotary direction combination, form not similar shape The head array mode of formula includes：

1. the flowing of interaction zone fluid is in the same direction between adjacent axial swirler；

2. the flowing of interaction zone fluid is reversed between adjacent axial swirler；

3. the direction of the region flowing between the axial swirler of any two interaction is all identical；

4. the direction of the region flowing between the axial swirler of any two interaction is all opposite.