A vertically injected composite fuel atomizing device and combustion chamber

Abstract

This application belongs to the field of combustion chamber design for aero-gas turbine engines, and specifically relates to a vertically injected composite fuel atomizing device and combustion chamber, comprising: a combustion chamber casing; a flame tube located within the combustion chamber casing; and a fuel atomizing device with one end fixed to the wall of the combustion chamber casing and the other end extending from the wall of the flame tube into the interior of the flame tube, wherein the axis of the fuel atomizing device is perpendicular to the axis of the flame tube; a fuel nozzle extending from the head of the flame tube into the flame tube and spraying fuel; wherein the fuel atomizing device includes a heat insulation sleeve and a spray bar assembly fitted within the heat insulation sleeve, the spray bar assembly and the heat insulation sleeve forming an air annular cavity, the side wall of the heat insulation sleeve having an air inlet for air from the combustion chamber casing to enter the air annular cavity, and the outlet end face of the spray bar assembly having an annular tangential hole for air from the air annular cavity to be discharged, the air discharged from the annular tangential hole atomizing the fuel sprayed into the flame tube by the spray bar assembly.

Description

Technical Field

[0001] This application belongs to the field of combustion chamber design for aero gas turbine engines, and specifically relates to a vertical injection composite fuel atomization device and combustion chamber. Background Technology

[0002] Current aero-engine gas turbine combustors typically employ a short annular flame tube. The atomizing device at the flame tube head mainly consists of a combination of pressure atomizing nozzles or air atomizing nozzles and single-stage or multi-stage swirlers. This atomizing device primarily serves to stabilize the flame and create a combustion zone. With continuous advancements in aero-engine technology, the air-fuel ratio in high-temperature combustion chambers is gradually increasing. More fuel needs to be burned efficiently in the flame tube head region. To avoid reduced combustion efficiency, exhaust smoke, and deterioration of the outlet temperature field under high operating conditions, the air volume at the combustion chamber head is continuously increasing. This leads to difficulties in ignition and flameout during rapid engine deceleration. If the traditional head-spray arrangement is used for fuel injection, it is difficult to address these issues. Therefore, a composite fuel injection device capable of achieving excellent atomization needs to be installed on the combustion chamber wall to assist in resolving the ignition and flameout problems caused by high-temperature rise.

[0003] In existing technologies, the combustion chamber fuel injection device is generally located in the swirling device area at the head of the combustion chamber flame tube. It consists of a fuel nozzle, a swirler, a transition section, and the flame tube wall. The swirler is used to create a recirculation zone within the flame tube, ensuring stable and efficient combustion. Fuel is supplied to the flame tube through the fuel nozzle at the flame tube head, and atomization is achieved through the pressure difference at the fuel nozzle orifice and the shearing action of the airflow from the main and auxiliary swirlers.

[0004] As the fuel-air ratio in advanced high-temperature combustion chambers gradually increases, in order to avoid problems such as reduced combustion efficiency, exhaust smoke, and deterioration of the outlet temperature field under high operating conditions, the amount of air at the head of the combustion chamber is constantly increasing, which leads to problems such as difficulty in ignition and flameout in the combustion chamber. Summary of the Invention

[0005] To address the aforementioned problems, this application provides a vertical injection composite fuel atomizing device and combustion chamber, comprising:

[0006] Combustion chamber casing;

[0007] The flame tube is located inside the combustion chamber casing;

[0008] And a fuel atomizing device with one end fixed to the combustion chamber casing wall and the other end extending from the flame tube wall into the flame tube, wherein the axis of the fuel atomizing device is perpendicular to the flame tube axis;

[0009] Fuel nozzles extend from the head of the flame tube into the flame tube and spray fuel.

[0010] The fuel atomizing device includes a heat insulation sleeve and a spray bar assembly fitted inside the heat insulation sleeve. The spray bar assembly and the heat insulation sleeve form an air annular cavity. The side wall of the heat insulation sleeve has an air inlet hole that allows air from the combustion chamber casing to enter the air annular cavity. The outlet end face of the spray bar assembly has an annular tangential hole that allows air from the air annular cavity to be discharged. The air discharged from the annular tangential hole atomizes the fuel injected into the flame tube by the spray bar assembly.

[0011] Preferably, the spray bar assembly includes a rod body, a transfer pipe, a cyclone separator 7, a nozzle, and an air inlet cap; the rod body has an oil passage inside, and a nozzle is installed at the outlet end of the oil passage. The outlet end of the nozzle is a cone, and the end of the cone has an oil outlet for spraying fuel in a conical manner. The air inlet cap is a cylinder fitted between the nozzle and the heat insulation sleeve. Its end face has a conical hole fitted on the nozzle cone. The surface of the cone, the inner wall of the end face of the air inlet cap, and the inner wall of the cylindrical surface of the air inlet cap form an air cavity. The conical hole and the cone form a seal. The air cavity has an air inlet that communicates with the air annular cavity. The annular tangential hole discharges air from the air cavity.

[0012] Preferably, the nozzle has a cylindrical installation space, and a swirler that swirls fuel is fitted inside the installation space. The outlet of the installation space is fitted with a transfer pipe through a stop, which fixes the swirler. The end face of the transfer pipe abuts against the stepped surface formed on the oil passage of the rod. The side wall of the nozzle bulges outward radially to form a stop, which is fitted and connected to the end face of the rod.

[0013] Preferably, the inlet of the rod body oil passage is equipped with an oil filter.

[0014] Preferably, the diameter of the annular tangential holes is between 0.6 and 1.2, the annular tangential angle is between 40 and 60 degrees, and the number of holes is 12 to 16.

[0015] Preferably, the air inlet of the heat insulation sleeve faces the head of the flame tube.

[0016] Preferably, the edge of the heat insulation sheath has multiple circumferentially distributed cooling holes, which blow out and cool the air in the air ring cavity.

[0017] Preferably, the angle between the cooling hole and the central axis is between 35 and 50 degrees, the hole diameter is between 0.8 and 1.5, and the number of holes is 8 to 12.

[0018] Preferably, the hydrocyclone is a centrifugal hydrocyclone with a spray cone angle of 80-100 degrees and the oil outlet of the nozzle has an expansion angle.

[0019] Preferably, the air inlet of the heat insulation sleeve is racetrack shaped.

[0020] The advantages of this application include: by setting wall-mounted spray nozzles on the flame tube wall, this spray device can utilize the air in the two channels of the combustion chamber to better atomize the finely atomized fuel. At the same time, the fuel can be directly supplied to the outer recirculation zone of the flame tube through the wall-mounted spray nozzles, increasing the local fuel concentration in the outer recirculation zone and forming a local fuel-rich combustion zone. This improves combustion stability, reduces the risk of combustion chamber flameout, and improves combustion chamber ignition performance and increases combustion chamber ignition success rate. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the combustion chamber of the composite fuel atomizing device with vertical injection mounted on the wall, as per this application.

[0022] Figure 2 This is a schematic diagram of the composite fuel atomizing device of this application.

[0023] Figure 3 This is a schematic diagram of the internal flow path structure of the composite fuel atomizing device of this application.

[0024] Figure 4 This is a schematic diagram of the head end face structure of the composite fuel atomizing device of this application. Detailed Implementation

[0025] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0026] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0027] like Figures 1-4 As shown, a combustion chamber includes:

[0028] Combustion chamber casing 14;

[0029] The flame tube 13 is located inside the combustion chamber casing 14;

[0030] And a fuel atomizing device 11, one end of which is fixed to the wall of the combustion chamber casing 14 and the other end of which extends from the wall of the flame tube 13 into the interior of the flame tube 13, wherein the axis of the fuel atomizing device 11 is perpendicular to the axis of the flame tube 13.

[0031] Fuel nozzle 12 extends into the flame tube 13 from the head and sprays fuel. Fuel nozzle 12 is connected to the combustion chamber casing 14, with its central axis perpendicular to the wall of the flame tube 13. Fuel atomizing device 11 has racetrack-shaped or tangential air inlets and is bolted to the casing. The combustion chamber airflow 100 is divided into air 101 and air 102. Air 101 is located between the combustion chamber casing 14 and the flame tube 13; a portion enters the nozzle's internal cavity through the heat insulation sleeve air inlet, while air 102 enters the flame tube through the wall. Fuel 51 enters the fuel nozzle 12 through the fuel inlet interface and is accelerated and rotated by a cyclone separator. At the nozzle position, it mixes with the surrounding swirling air and is atomized and sprayed out by air shearing. The resulting cone-shaped liquid mist enters the internal region of the flame tube through air shearing. Fuel 52 enters the fuel atomizing device 11, swirls through the cyclone separator, and is then sprayed out as a mist.

[0032] The pneumatic composite fuel nozzle, which achieves efficient fuel atomization by spraying fuel from the flame tube wall, mainly includes a heat insulation sleeve 1, a rod body 2, an air inlet cap 3, a gasket 4, an oil filter 5, a transfer pipe 6, a cyclone separator 7, a nozzle 8, and a gasket 9. Specifically, it is a fuel atomizing device with a separate oil-gas channel. The heat insulation sleeve 1 is a hollow cylinder with a bolt mounting edge on one end and uniformly distributed tangential holes on the other. A racetrack-shaped air inlet is located on the cylindrical surface near the holes, perpendicular to the cylinder's central axis. The heat insulation sleeve 1 is bolted to the rod body 2 and has a metal sealing gasket. The rod body 2 has a threaded connector at one end, a cylindrical mounting seat in the middle, and a hollow structure with a positioning hole at the other end. A stepped hole is provided at the oil inlet end of the rod body, and a cylindrical oil filter 5 is installed inside the stepped hole to filter the inlet fuel. After passing through the oil filter 5, the fuel enters the transfer pipe 6 along the internal elongated hole. The nozzle 8 is a cylindrical structure with an inner hole. One end of the nozzle is conical, and its interior has a stepped surface. The cyclone separator 7 is installed inside the nozzle 8 and is tightly pressed against the inner end face of the nozzle 8. The cyclone separator 7 has an oil inlet and a tangential groove. The other end face of the cyclone separator is pressed against the end face of the transfer pipe 6. The transfer pipe 6 is a cylindrical structure with a stepped surface and an internal oil inlet. The step of the transfer pipe is pressed against the end face of the nozzle 8 and welded. The nozzle 8, cyclone separator 7, and transfer pipe 6 are welded together. One end of the transfer pipe 6 is pressed against the stepped position of the inner positioning hole of the rod body 2. The outer end face of the nozzle is pressed by the air inlet cap 3. A gasket 4 is placed between the nozzle and the rod body. After pressing, the air inlet cap 3 is welded to the outer circle of the rod body for positioning. The air inlet cap is a cylindrical structure with an inner annular channel. The end of the annular channel has a stepped surface. The stepped surface and the outlet end face form a constricting conical channel. The outer cylindrical end of the air inlet cap has a tangential hole near the inner conical surface. The outlet end face has multiple evenly distributed annular tangential holes.

[0033] The spray device is a conical structure with annular air atomization, installed on the wall of the flame tube. It mainly includes a central fuel cone area, an outer ring atomization area, and an end-face cooling area. Fuel 52 enters the internal channel from the nozzle of the rod, passes through the oil inlet of the cyclone separator to the cyclone groove, and after high-speed rotation, it is atomized and sprayed out as a conical liquid film 70 through the nozzle. The conical liquid film is sprayed into the interior of the flame tube. Air 101 in the two channels of the combustion chamber enters the interior of the heat insulation sleeve through the side air inlet of the heat insulation sleeve and flows in the annular channel between the outside of the rod and the heat insulation sleeve. Air 101 and air 40 are divided into two parts. The first part of the air forms airflow 60 and airflow 30 respectively, and then enters the end face tangential hole of the air inlet cap and flows out in a rotating manner to form airflow 30. The other part is sprayed out through the oblique hole on the end face of the heat insulation sleeve to form airflow 20.

[0034] The main structural parameters described in this patent include:

[0035] The aforementioned fuel injection device has an external heat insulation sleeve with an auxiliary air intake hole. The direction of the air intake hole is the same as the air intake direction in the flame tube and the casing cavity, which is in the direction of airflow. The angle between the hole and the nozzle housing is 90 degrees, the hole shape is racetrack-shaped, and the longer side of the hole is 2-3 times the shorter side.

[0036] The fuel injection device described above has an annular tangential hole on the outer ring of the nozzle outlet end face. The hole diameter is between 0.6 and 1.2, the annular tangential angle is between 40 and 60 degrees (45 degrees in the example), and the number of holes is between 12 and 16.

[0037] The fuel injection device has cooling holes evenly distributed circumferentially on the outermost ring of the nozzle outlet end face, with the angle between the holes and the central axis between 35 and 50 degrees, the hole diameter between 0.8 and 1.5 degrees, and the number of holes between 8 and 12.

[0038] The composite fuel nozzle that achieves efficient fuel atomization by spraying fuel from the wall of the flame tube should not have an excessively large flow rate, and its flow rate ratio to that of the nozzle at the head of the flame tube should be between 22 and 43.

[0039] The internal front end hydrocyclone is a centrifugal hydrocyclone with a jet cone angle of 80-100 degrees and an expansion angle at the outlet end face (90 degrees in this embodiment).

[0040] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A vertically injected composite fuel atomizing device and combustion chamber, characterized in that, include: Combustion chamber casing (14); The flame tube (13) is located inside the combustion chamber casing (14); And a fuel atomizing device (11) with one end fixed to the wall of the combustion chamber casing (14) and the other end extending from the wall of the flame tube (13) into the interior of the flame tube (13), wherein the axis of the fuel atomizing device (11) is perpendicular to the axis of the flame tube (13); Fuel nozzle (12) extends into the flame tube (13) from the head and sprays fuel; The fuel atomizing device (11) includes a heat insulation sleeve (1) and a spray bar assembly fitted inside the heat insulation sleeve (1). The spray bar assembly and the heat insulation sleeve (1) form an air annular cavity. The side wall of the heat insulation sleeve (1) has an air inlet hole for allowing air from the combustion chamber casing (14) to enter the air annular cavity. The outlet end face of the spray bar assembly has an annular tangential hole for allowing air from the air annular cavity to be discharged. The air discharged from the annular tangential hole causes the fuel atomized by the spray bar assembly sprayed into the flame tube (13).

2. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 1, characterized in that, The spray bar assembly includes a rod body (2), a transfer pipe (6), a cyclone separator (7), a nozzle (8), and an air inlet cap (3). The rod body (2) has an oil passage inside, and the nozzle (8) is installed at the outlet end of the oil passage. The outlet end of the nozzle (8) is a cone, and the end of the cone has an oil outlet for spraying fuel in a conical manner. The air inlet cap (3) is a cylinder fitted between the nozzle (8) and the heat insulation sleeve (1). Its end face has a conical hole fitted on the cone of the nozzle (8). The surface of the cone, the inner wall of the end face of the air inlet cap (3), and the inner wall of the cylindrical surface of the air inlet cap (3) form an air cavity. The conical hole and the cone form a seal. The air cavity has an air inlet that connects to the air annular cavity. The annular tangential hole discharges air from the air cavity.

3. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 1, characterized in that, The nozzle (8) has a cylindrical installation space, and the installation space is fitted with a swirler (7) that swirls the fuel. The outlet of the installation space is fitted with a stop and a transfer pipe (6) is installed. The transfer pipe (6) fixes the swirler (7). The end face of the transfer pipe (6) abuts against the stepped surface formed on the oil line of the rod (2). The side wall of the nozzle (8) bulges outward radially to form a stop and is connected to the end face of the rod (2).

4. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 3, characterized in that, The rod body (2) has an oil filter (5) at the inlet of the oil passage.

5. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 3, characterized in that, The diameter of the annular tangential holes is between 0.6 and 1.2 mm, the annular tangential angle is between 40 and 60 degrees, and the number of holes is 12 to 16.

6. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 3, characterized in that, The air inlet of the heat insulation sleeve (1) faces the head of the flame tube.

7. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 6, characterized in that, The heat insulation sleeve (1) has multiple circumferentially distributed cooling holes on its end face edge, which blow out the air from the air ring cavity for cooling.

8. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 7, characterized in that, The angle between the cooling holes and the central axis is between 35 and 50 degrees, the hole diameter is between 0.8 and 1.5, and the number of holes is 8 to 12.

9. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 3, characterized in that, The hydrocyclone (7) is a centrifugal hydrocyclone with a spray cone angle of 80-100 degrees and an oil outlet with an expansion angle.

10. The vertical injection composite fuel atomizing device and combustion chamber as described in claim 1, characterized in that, The air inlet of the heat insulation sleeve (1) is runway shaped.

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