CN103266922B - Turbine stator blade with interstage combustor - Google Patents

Abstract

A turbine stator blade with an interstage combustion chamber relates to a turbine stator blade of an aero-engine or a gas turbine. Including inner ring, outer ring and multiple guide vanes; the guide vane is provided with a guide vane body and a guide vane cover, the guide vane cover is arranged at the upper end of the guide vane body, and the guide vane body is provided with an oil injection chamber in the front and a return chamber in the middle and the cooling cavity at the rear; there is also a cooling cavity at the rear of the guide vane cover, and there is a spray rod slot inside the oil injection cavity; cooling holes are provided in the cooling cavity of the guide vane body and the cooling cavity of the guide vane cover; there are also points The ignition device and a plurality of spray rod devices, the ignition device is provided with an ignition seat and an ignition nozzle; the spray rod device is installed on the guide vane, the outer end of the spray rod device passes through and exposes the outer ring, and the inner end of the spray rod device extends into the The oil injection cavity of the guide vane, the spray bar device is provided with oil pipe, air pipe and nozzle, the nozzle is provided with oil injection port and multiple air injection ports, and the oil pipe and air pipe are respectively connected with the oil supply pipe and the air supply pipe.

Description

A turbine stator blade with an interstage combustion chamber

technical field

The invention relates to a turbine stator blade of an aeroengine or a gas turbine, in particular to a turbine stator blade with an interstage combustion chamber.

Background technique

In order to improve the power performance of aeroengines or gas turbines, there are usually methods such as increasing the boost ratio of the compressor and increasing the temperature before the turbine, but the potential for such research to be tapped is already small.

The Interstage Turbine Burner (ITB) has been proposed as a new idea in recent years. It increases the heat circulation by adding a combustion chamber between the high-pressure and low-pressure turbines of the aeroengine, thereby increasing the engine power. Since the combustion chamber is arranged between two turbine stages, compared with the main combustion chamber, its inlet airflow temperature and velocity are higher, and it has higher requirements for flame stabilization; compared with the afterburner, due to the consideration of the subsequent The tolerance limit of the low-pressure turbine, the temperature rise cannot be too high, so the requirement for lean combustion performance is high; at the same time, due to the limited space between the turbine stages, the design of the combustion chamber also needs to consider the compactness.

Trapped Vortex Combustor (TVC) is a solution that can be used as an interstage combustor. It consists of a concave cavity and a main flow, where air and fuel are rapidly mixed and burned to form a recirculation zone. Because the concave cavity is shielded from the main flow area, the flame is formed independently, so it can maintain stable operation under a wide range of flow conditions. The trapped vortex combustor has the advantages of wide stable working range, superior lean quenching performance, simple structure and low pollution emission. However, when it is applied to the interstage combustion of an aero-engine, it needs to increase a certain axial length, which is not conducive to the weight control of the engine.

The patent application with the publication number CN1858498 discloses a tangential trapped vortex combustion chamber, which uses the high centrifugal acceleration generated by the tangential swirl to enhance the combustion of the liquid mist, and a mixing hole is provided at the position before the exit of the combustion chamber to ensure its good outlet temperature distribution.

The ultra-compact combustor (Ultra-Compact Combustior, UCC) is another scheme proposed by the Air Force Research Laboratory (AFRL) in 2002 that can be used as an interstage combustor. Its structural feature is that an annular cavity is arranged circumferentially on the outer ring of the turbine vane case, similar to the TVC scheme. In the cavity, the gas flow rotates around the axis to enhance the mixing of oil, gas and gas. Due to the centrifugal force generated by the rotating flow, the radial pressure gradient exists, which also strengthens the gas transmission in the radial direction. The tangential cavity provides sufficient residence time for fuel-rich combustion, and the circulation of combustion products also stabilizes the flame. High centrifugal force can speed up the flame propagation speed to a certain extent, which greatly improves the combustion efficiency and combustion stability. The rotational speed near the axis is small, forming a low-speed zone, which can be used as a stable high-temperature source. The flame spreads into the axial main flow through specially shaped grooves in the stator blades. In simple terms, the tangential cavity can be regarded as the main combustion zone, the radial groove on the vane is the middle zone, and the rear part of the vane of the mainstream is the mixing zone. The biggest advantage of the UCC scheme is that it can be equivalent to the axial size of the turbine stator blades, only a small amount of radial space is added without occupying the axial space, and no separate components are added, which avoids increasing the overall weight of the engine. However, both experimental research and numerical simulation on UCC are still in the preliminary stage.

Contents of the invention

The purpose of the present invention is to provide a device that can overcome the difficulties caused by the high flow rate and high temperature of the inlet airflow, solve the problems of lean combustion, stable flame and blade cooling, etc., has good lean oil flameout characteristics, can significantly improve the atomization effect, and reduce clogging. A turbine stator blade with an interstage combustion chamber.

The invention includes an inner ring, an outer ring and a plurality of guide vanes; the outer ring is provided with a cooling cavity, the cooling cavity is provided with an air inlet, each guide vane is arranged between the inner ring and the outer ring, and the main channel is formed between each guide vane ; which is characterized by:

The guide vane is provided with a guide vane body and a guide vane cover. The guide vane cover is arranged on the upper end of the guide vane body. The guide vane body is provided with an oil injection chamber at the front, a return chamber at the middle and a cooling chamber at the rear; the rear part of the guide vane cover There is also a cooling chamber, and there is a spray rod slot inside the oil injection chamber, and the oil injection chamber communicates with the main channel; the cooling chamber of the guide vane body communicates with the cooling chamber of the guide vane cover and the cooling chamber of the outer ring, and the cooling chamber of the guide vane body Cooling holes are provided in the cavity and the cooling cavity of the guide vane cover;

The turbine stator blades with interstage combustion chambers are also provided with an ignition device and a plurality of spray rod devices, the ignition device is provided with an ignition seat and an ignition nozzle, the ignition seat is installed on the outer ring, and the ignition nozzle is fixed on the ignition seat and pass through the cooling cavity of the outer ring; the spray rod device is installed on the guide vane, the outer end of the spray rod device passes through and exposes the outer ring, the inner end of the spray rod device extends into the oil spray chamber of the guide vane, and the spray rod device There are oil pipes, air pipes and nozzles. The oil pipes are arranged inside the air pipes. The nozzles are arranged on the oil pipes and air pipes. The nozzles are equipped with oil injection ports and multiple air injection ports. and the air pipe are respectively connected with the oil supply pipe and the air supply pipe.

Generally, there can be two ignition seats and ignition nozzles; six to twelve spray rod devices, which are evenly distributed. The number of spray rod devices is correspondingly equal to the number of guide vanes.

The fuel injection port of the nozzle is preferably arranged at the center of the nozzle, and there may be 4 air injection ports, and the 4 air injection ports are offset oblique holes, which are all arranged around the fuel injection port.

A baffle is provided at the tail end of the fuel injection chamber, and a narrow slit is provided in front of the baffle, through which the fuel injection chamber communicates with the main channel. The baffle is an angled baffle of 120°.

Compared with the prior art, the beneficial effects of the present invention are as follows:

Due to the adoption of the above technical solution, the present invention can transform the guide vane of the low-pressure turbine into an interstage combustion chamber with a flame-stabilizing effect. The nozzle sprays a mixture of oil and gas to the fuel injection cavity at the front of the guide vane, and the atomized fuel evaporates and absorbs heat on the inner surface of the guide vane, which can not only cool the vane but also vaporize the fuel to facilitate combustion. Combustion between the turbine stator blades can be achieved by ignition, increasing the power of the entire engine. Pneumatic atomization fuel injection is adopted, the atomization effect is good, and it has good lean flameout characteristics; a single blade is transformed into a flame stabilizer, which minimizes the blocking ratio. Utilizing the flame-stabilizing effect of the recirculation cavity in the middle of the guide vane, successful ignition can be achieved under high-speed airflow and the stable working boundary can be broadened.

This shows that the present invention has the following prominent advantages:

(1) With an interstage combustion chamber, it can supplement the work loss of the high-temperature gas after it expands through the high-pressure turbine, increase the temperature rise of the gas through the organization of combustion, improve the working ability of the gas, and then increase the overall power of the engine;

(2) There is no need to increase the axial length and radial length, the structure is relatively simple, the occupied volume is small, and the weight increase brought to the entire engine is also small;

(3) The fuel injection device adopts a pneumatic atomization structure, which combines fuel evaporation with guide vane cooling to improve fuel combustion efficiency;

(4) The tail of the guide vane is equipped with a cooling hole structure. The cooling gas flows from the cooling cavity channel into the combustion channel, forming a layer of gas film to cover the tail of the guide vane. At the same time, the cooling gas can also strengthen the mixing of the combustion zone and the main flow.

(5) Each air injection port is an offset oblique hole, so that the air flow will not converge toward one point, but each offset a small distance in the clockwise direction, so that the swirl flow can be generated, which can enhance the air flow to the fuel. Atomization.

Description of drawings

FIG. 1 is a schematic diagram of the appearance structure of an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional structure diagram of an embodiment of the present invention.

Fig. 3 is a schematic diagram of the appearance structure of the guide vane and spray bar device according to the embodiment of the present invention.

Fig. 4 is a schematic top view of the structure of the guide vane main body of the guide vane according to the embodiment of the present invention.

FIG. 5 is a schematic cross-sectional structure diagram of FIG. 3 .

Fig. 6 is a schematic diagram of the appearance and structure of the spray bar device in Fig. 3 .

Fig. 7 is a front structural schematic diagram of a nozzle according to an embodiment of the present invention.

Detailed ways

Referring to Figures 1 to 7, the embodiment of the present invention is provided with an outer ring 1, a guide vane body, a guide vane body 2, a guide vane cover 3, an inner ring 4, and 2 ignition devices (including an ignition seat 7 and an ignition nozzle (not shown in the figure) Draw)) and 8 spray rod devices 6 are formed.

The outer ring 1 is provided with a cooling chamber 11 , and the cooling chamber 11 is provided with an air inlet 5 . The guide vane is arranged between the inner ring 4 and the outer ring 1 , the guide vane is provided with a guide vane main body 2 and a guide vane cover 3 , and the guide vane cover 3 is arranged on the upper end surface of the guide vane main body 2 . The main body 2 of the guide vane is provided with an oil injection cavity 201 at the front, a return flow cavity 204 at the middle and a cooling cavity 205 at the rear; there is a spray bar slot 207 inside the oil injection cavity 201, and a baffle 202 is provided at the end of the oil injection cavity 201 , The baffle plate 202 is an angled baffle plate of 120°, and a narrow slit 203 is provided in front of the baffle plate 202, and the narrow slit 203 connects the fuel injection chamber with the main flow channel. The guide vane cover 3 is fixed on the upper end of the guide vane main body 2, the oil injection chamber 201 and the return flow chamber 204 are only provided on the guide vane main body 2, and the cooling chamber 205 extends to the guide vane cover 3 and communicates with the cooling chamber 11 of the outer ring . The recirculation cavity 204 is the main recirculation area, and forms a flame stabilizer together with the guide vane cover 3 . Two rows of cooling holes 206 (both rows of cooling holes 206 are 30° to the axial direction and have a diameter of 1mm) are provided on both sides of the cooling cavity 205 shared by the guide vane body 2 and the guide vane cover 3 .

The ignition seat 7 is installed on the outer ring 1, and the ignition nozzle (not shown in the figure) is fixed on the ignition seat 7 and extends into the main channel through the outer ring cooling chamber 11.

Eight spray rod devices 6 are evenly distributed. Each spray rod device 6 is correspondingly installed on a guide vane guide vane main body 2 . The outer end of the spray rod device 6 passes through and exposes the outer ring 1, and the inner end of the spray rod device 6 extends into the oil injection chamber 201. The spray rod device 6 is provided with an oil pipe 602, an air pipe 601 and a nozzle 603, and the oil pipe 602 is arranged inside the air pipe 601. The nozzle 603 is set on the oil pipe 602 and the air pipe 601. The nozzle 603 is provided with an oil injection port 604 and four air injection ports 605. The oil injection port 604 communicates with the oil pipe 602. Each air injection port 605 communicates with the air pipe 601. The oil pipe 602 and the air pipe 601 They are respectively connected with an external oil supply device (not shown in the figure) and an air supply device (not shown in the figure).

Eight spray rod devices 6 are evenly distributed. The fuel injection port 604 of the nozzle 603 is located at the center of the nozzle 603 , and the four air injection ports 605 are offset oblique holes, and are all arranged around the fuel injection port 604 .

The working principle of this embodiment is as follows:

The air pipe 601 of the spray rod device 6 introduces high-pressure air from an external air supply device (such as a compressor), and sprays it into the fuel injection chamber 201 at high speed from the four air injection ports 605. It is sprayed into the fuel injection chamber 201. Four beams of gas are jointly injected towards the fuel in a slightly off-center direction, so that the fuel is rapidly atomized, and at the same time, a swirling liquid mist of a certain intensity is generated, and the liquid mist then hits the head of the fuel injection chamber 201, Since the front edge of the outer surface of the oil injection chamber 201 (ie, the guide vane 2 ) directly faces the high-temperature incoming flow, the wall temperature of the entire oil injection chamber 201 is relatively high. The temperature of the air ejected from the jet port 605 is relatively low, and the high-speed impact of the air on the wall can have a cooling effect. At the same time, the liquid mist hits the wall to evaporate and absorb heat, which can not only cool the wall but also strengthen the evaporation of fuel. After interacting with the wall surface, the oil-gas mixture is finally sprayed into the main channel from the narrow slit 203 in front of the tail end baffle 202, and part of the mixture enters the return cavity 204 in the middle of the guide vane 2, forming a stable small-scale return flow in the return cavity 204 zone, and part of the mixture enters the main flow channel, mixes with the high-temperature gas of the main flow, and burns in the main flow channel near the rear of the recirculation cavity 204 . Different from the cut-off vortex burner introduced in the Chinese Patent Publication No. CN1784574A, which injects fuel from the middle of the rear body, the embodiment of the present invention uses a pneumatic atomization spray rod device 6 to supply fuel, and the fuel is first fully injected into the fuel injection chamber 201. After atomization, it is sprayed into the main stream from both sides of the front part, and most of the fuel is burned and consumed in the main stream. In addition, the recirculation cavity 204 plays the role of cross-flame during ignition.

Cooling gas enters the outer ring cooling cavity 11 from the cooling cavity air inlet 5, and then enters the rear cooling cavity 205 of each guide vane 2, and is discharged into the main flow through a plurality of cooling holes 206 provided on both sides of the cooling cavity 205. Note that the burning flame mainly appears at the rear of the guide vane 2, and the cold air jets coming out from the cooling holes 206 can form a Coanda film at the rear of the guide vane 2, thereby isolating the guide vane 2 from the high-temperature gas, ensuring Reliable operation of guide vanes 2. At the same time, each cooling air jet strengthens the transverse disturbance of the main flow, thereby promoting the mixing of components in the flow field, which is beneficial to the uniform temperature distribution at the outlet of the flow field.

Claims (6)

1. A turbine stator blade with an interstage combustion chamber, comprising an inner ring, an outer ring and a plurality of guide vanes; the outer ring is provided with a cooling cavity, the cooling cavity is provided with an air inlet, and each guide vane is located between the inner ring and the Between the outer rings and between the guide vanes is the main channel; it is characterized in that: The guide vane is provided with a guide vane main body and a guide vane cover. The guide vane cover is arranged on the upper end of the guide vane main body. The guide vane main body is provided with an oil injection chamber at the front edge, a return flow chamber at the middle part and a cooling chamber at the trailing edge; the rear part of the guide vane cover There is also a cooling chamber, and there is a spray rod slot inside the oil injection chamber, and the oil injection chamber communicates with the main channel; the cooling chamber of the guide vane body communicates with the cooling chamber of the guide vane cover and the cooling chamber of the outer ring, and the cooling chamber of the guide vane body Cooling holes are provided in the cavity and the cooling cavity of the guide vane cover; The turbine stator blades with interstage combustion chambers are also provided with an ignition device and a plurality of spray rod devices, the ignition device is provided with an ignition seat and an ignition nozzle, the ignition seat is installed on the outer ring, and the ignition nozzle is fixed on the ignition seat and pass through the cooling cavity of the outer ring; the spray rod device is installed on the guide vane, the outer end of the spray rod device passes through and exposes the outer ring, the inner end of the spray rod device extends into the oil spray chamber of the guide vane, and the spray rod device There are oil pipes, air pipes and nozzles. The oil pipes are arranged inside the air pipes. The nozzles are arranged on the oil pipes and air pipes. The nozzles are equipped with oil injection ports and multiple air injection ports. and the air pipe are respectively connected with the oil supply pipe and the air supply pipe. 2 . A turbine stator blade with an interstage combustion chamber as claimed in claim 1 , wherein there are two ignition devices. 3 . 3 . A turbine stator blade with an interstage combustion chamber as claimed in claim 1 , characterized in that: 6 to 12 spray rod devices are arranged in an even distribution. 4 . 4. A turbine stator blade with an interstage combustion chamber as claimed in claim 1, characterized in that: the fuel injection port of the nozzle is located at the center of the nozzle, and the air injection ports are provided with 4, 4 air injection ports The ports are offset oblique holes, and they are all arranged around the fuel injection ports. 5. A turbine stator blade with an interstage combustion chamber as claimed in claim 1, wherein a baffle is provided at the tail end of the fuel injection cavity, and a slit is provided in front of the baffle, through which, The fuel injection cavity communicates with the main flow channel. 6 . A turbine stator blade with an interstage combustion chamber as claimed in claim 5 , wherein the baffle is an angled baffle with an angle of 120°. 7 .