Small molecule gel oxidant submerged staged combustion injector

Abstract

The small molecule gel oxidizer submerged staged combustion injector of the present invention comprises a cylindrical inlet, a conical section, a flow-around section, a straight section, an axial connecting section, and a radial connecting section connected in sequence. The conical section, flow-around section, and straight section are all double-layered structures. The outer walls of the conical section, flow-around section, and straight section are connected in sequence to form an outer wall, with both ends connected to the cylindrical inlet and the axial connecting section, respectively. The inner walls of the conical section, flow-around section, and straight section are connected in sequence to form an inner wall, with one end closed and the other end connected to the outer wall. The cavity between the outer and inner walls and the cylindrical inlet constitute an oxidizer chamber. The cavity enclosed by the inner wall constitutes a secondary fuel combustion chamber. A fuel combustion passage is provided within the conical section, communicating with the secondary fuel combustion chamber. An array of injection holes is formed on the inner wall. This invention increases the residence time and turbulence of the oxidizer and fuel within the combustion chamber, and achieves staged combustion, thereby improving engine combustion efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aerospace propulsion, in particular to a small-molecule gel oxidant submerged staged combustion injector. BACKGROUND

[0002] Red fuming nitric acid is a mixture of dinitrogen tetroxide and nitric acid, which has the characteristics of low freezing point, high boiling point and large density, and is an oxidant used in liquid rocket engines. In order to improve the long-term storage performance of liquid oxidant and reduce the harm caused by accidental leakage, a small-molecule solidification factor is added to the red fuming nitric acid, so that the oxidant changes from liquid to solid, avoiding the pre-packaging and leakage risks of existing liquid propellants. At the same time, it can be converted from solid to liquid under the action of shear force, and the thrust of the rocket engine can be continuously adjusted based on the flow regulating device.

[0003] The existing solid fuel and liquid oxidant engine injector generally injects oxidant at the head, and the combustion gas generated by the combustion of the solid fuel in the hole mixes with the oxidant injected at the head and burns. This combustion mode causes the oxidant to be highly concentrated at the head and gradually decrease towards the nozzle, resulting in uneven regression of the solid fuel burning surface and low combustion efficiency of the engine, which is a major difficulty in the development of solid fuel and liquid oxidant mixed combustion engine technology. SUMMARY

[0004] The purpose of the present application is to provide a small-molecule gel oxidant submerged staged combustion injector to solve the problems of unreasonable concentration distribution of oxidant after injection, uneven regression of solid fuel burning surface, and low combustion efficiency of existing solid fuel and liquid oxidant mixed combustion engine.

[0005] In order to achieve the above purpose, the present application provides a small-molecule gel oxidant submerged staged combustion injector, which comprises a cylindrical inlet, a conical section, a flow-around section, a straight section, an axial connecting section and a radial connecting section connected in sequence; the conical section, the flow-around section and the straight section are double-layer structures; the outer walls of the conical section, the flow-around section and the straight section are connected in sequence to form an outer wall, which is connected to the cylindrical inlet and the axial connecting section at both ends; the inner walls of the conical section, the flow-around section and the straight section are connected in sequence to form an inner wall, which is closed at one end and connected to the outer wall at the other end; the cavity between the outer wall and the inner wall and the cylindrical inlet form an oxidant chamber; the cavity enclosed by the inner wall forms a fuel secondary combustion chamber, which is through the axial connecting section; the conical section is provided with a fuel gas passage which is through the fuel secondary combustion chamber; and an array of injection holes is formed on the inner wall.

[0006] In the aforementioned small molecule gel oxidant submerged staged combustion injector, a plurality of fan-shaped flow holes are formed on both the outer and inner walls of the conical section, with the fan-shaped flow holes on the inner wall corresponding one-to-one with those on the outer wall; a plurality of channels are provided between the outer and inner walls of the conical section, the channels being used to connect the fan-shaped flow holes on the outer wall and the fan-shaped flow holes on the inner wall, forming a fuel combustion passage.

[0007] The aforementioned small molecule gel oxidant submerged staged combustion injector has fuel gas passages evenly arranged along the circumference.

[0008] In the above-mentioned small molecule gel oxidant submerged staged combustion injector, the injection hole array is provided with multiple injection hole circumferential sub-arrays along the straight section axial direction, and the injection holes in each circumferential sub-array are uniformly arranged along the circumference of the straight section.

[0009] In the above-mentioned submerged staged combustion injector for small molecule gel oxidants, the diameters of the injection holes in different circumferential sub-arrays are not exactly the same; the number of injection holes in different circumferential sub-arrays is not exactly the same.

[0010] In the above-mentioned small molecule gel oxidant submerged staged combustion injector, the outer wall of the flow section protrudes outward.

[0011] In the above-mentioned small molecule gel oxidant submerged staged combustion injector, a flow-around plate is provided on the inner wall of the flow-around section, and the flow-around plate is located between the outer wall and the inner wall of the flow-around section.

[0012] In the above-mentioned submerged staged combustion injector for small molecule gel oxidants, the axial connecting section is perpendicular to the radial connecting section, and the connection between the axial connecting section and the radial connecting section is machined with a transition fillet.

[0013] In the above-mentioned small molecule gel oxidant submerged staged combustion injector, the cylindrical inlet, the conical section, the flow-around section, and the straight section are formed by 3D printing, the axial connecting section and the radial connecting section are integrally formed by machining, and the outer wall of the straight section is welded to the axial connecting section.

[0014] The aforementioned small molecule gel oxidizer submerged staged combustion injector, wherein solid fuel is ignited and burned according to the engine ignition sequence to produce fuel-rich gas, which enters the secondary combustion chamber through the fuel gas passage; liquefied small molecule gel oxidizer enters the oxidizer chamber from the cylindrical inlet, the oxidizer carries away the heat from the inner and outer walls, and is simultaneously ejected from the injection holes of the injection hole array into the secondary combustion chamber, where it mixes and burns with the fuel-rich gas.

[0015] Compared with the prior art, the beneficial technical effects of the present invention are:

[0016] (1) can be transported to the inside of the combustion chamber, according to the axial concentration distribution of fuel gas injection oxidant, significantly improve the fuel gas and oxidant mixing turbulence, help to improve the engine combustion efficiency;

[0017] (2) can be and fuel gas flow regulation structure together, adjust the fuel gas flow, with the oxidant to achieve the best oxygen combustion ratio, realize the engine thrust regulation and high efficiency combustion;

[0018] (3) small molecule gel oxidant flow into liquid, using the high efficiency of heat transfer capacity of liquid, heat protection of injector structure, solid fuel gas from the engine front to the rear, increase the residence time of oxidant and fuel gas in the combustion chamber, improve the combustion efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0019] The small molecule gel oxidant of the application is given by the following examples and drawings.

[0020] Figure 1 The small molecule gel oxidant of the application is given by the following examples and drawings.

[0021] Figure 2 The small molecule gel oxidant of the application is given by the following examples and drawings.

[0022] Figure 3 The small molecule gel oxidant of the application is given by the following examples and drawings. DETAILED DESCRIPTION

[0023] The following will be combined Figures 1-3 The small molecule gel oxidant of the application is given by the following examples and drawings.

[0024] Figure 1 The small molecule gel oxidant of the application is given by the following examples and drawings. Figure 2 The small molecule gel oxidant of the application is given by the following examples and drawings.

[0025] Combined Figure 1 And Figure 2 The small molecule gel oxidant of the application is given by the following examples and drawings.

[0026] The conical section 12, the flow-around section 13 and the straight section are all double-layer structures; the outer wall of the conical section 12, the outer wall 4 of the flow-around section 13 and the outer wall 9 of the straight section are connected in sequence to form an outer wall, the two ends of which are connected with the cylindrical inlet 1 and the axial connecting section 2 respectively, specifically, the cylindrical inlet 1 is connected with the outer wall of the conical section 12, and the axial connecting section 2 is connected with the outer wall 9 of the straight section; the inner wall of the conical section 12, the inner wall of the flow-around section 13 and the inner wall 6 of the straight section are connected in sequence to form an inner wall, one end of which is closed, and the other end is connected with the outer wall, specifically, one end of the inner wall of the conical section 102 which is not connected with the inner wall of the flow-around section is closed, and one end of the inner wall 6 of the straight section which is not connected with the inner wall of the flow-around section is connected with the outer wall 9 of the straight section (see Figure 2 the intermediate partial enlarged view);

[0027] As Figure 1 and Figure 3 , a plurality of fan-shaped flow-through holes 10 are formed on the outer wall 15 and the inner wall 16 of the conical section 102, the plurality of fan-shaped flow-through holes 10 are uniformly arranged along the circumference, the fan-shaped flow-through holes on the inner wall 16 are opposite to the fan-shaped flow-through holes on the outer wall 15, that is, the number of the fan-shaped flow-through holes on the inner wall 16 is equal to the number of the fan-shaped flow-through holes on the outer wall 15, and the arrangement positions of the fan-shaped flow-through holes on the inner wall 16 coincide with the arrangement positions of the fan-shaped flow-through holes on the outer wall 15; a plurality of channels 17 are arranged between the outer wall 15 and the inner wall 16 of the conical section 102, the channels 17 are used to connect the fan-shaped flow-through holes on the opposite outer wall 15 and the fan-shaped flow-through holes on the inner wall 16, thereby forming fuel gas channels;

[0028] As Figure 2 , a plurality of injection hole arrays are formed on the inner wall 6 of the straight section, in this embodiment, a plurality of injection hole annular sub-arrays are arranged along the axial direction of the straight section, and the injection holes in each annular sub-array are uniformly arranged along the circumference of the straight section; the diameters of the injection holes in different annular sub-arrays can be different, for example, the diameter of the injection hole I 7 is 0.4 mm, and the diameter of the injection hole II 8 is 0.6 mm; the number of injection holes in different annular sub-arrays can be different, for example, the annular sub-array in which the injection hole I 7 is located contains 24 injection holes, and the annular sub-array in which the injection hole II 8 is located contains 20 injection holes;

[0029] The cavity between the outer wall and the inner wall and the cylindrical inlet 1 form an oxidant chamber 14, the cylindrical inlet 1 is the inlet of the oxidant chamber 14, and the cylindrical inlet 1 is connected with an upstream oxidant conveying system (not shown in the figure);

[0030] The cavity enclosed by the inner wall forms a fuel secondary combustion chamber 11, and the fuel secondary combustion chamber 11 is through the axial connecting section 2.

[0031] As Figure 2The outer wall 4 of the flow-around section 13 is outwardly convex, and the flow-around plate 5 is arranged on the inner wall of the flow-around section 13 and located between the outer wall 4 of the flow-around section 13 and the inner wall of the flow-around section 13.

[0032] In the embodiment, the cylindrical inlet 1, the conical section 12, the flow-around section 13 and the straight section are formed by 3D printing, and the thicknesses of the inner wall and the outer wall are both 0.8 mm; the axial connecting section 2 and the radial connecting section 3 are integrally formed by machining, the axial connecting section 2 is perpendicular to the radial connecting section 3 (i.e., the two are at 90°), and a transition fillet is processed at the connection between the axial connecting section 2 and the radial connecting section 3; and the outer wall 9 of the straight section is welded to the axial connecting section 2.

[0033] The working principle of the small-molecule gel oxidant submerged staged combustion injector in the embodiment is as follows:

[0034] According to the engine ignition timing, the solid fuel is ignited and combusted to generate fuel-rich gas, the fuel-rich gas enters the fuel secondary combustion chamber 11 through the fuel gas passage (composed of the fan-shaped flow-through hole and the passage 17); the oxidant delivery system provides pressure for oxidant extrusion, the liquefied small-molecule gel oxidant enters the oxidant chamber 14 from the cylindrical inlet 1, the oxidant takes away the heat of the inner wall and the outer wall, and is sprayed from the injection holes of the injection hole array into the fuel secondary combustion chamber 11 to mix and combust with the fuel-rich gas;

[0035] The flow-around section 13 is arranged between the conical section 12 and the straight section to realize fuel gas flow regulation together with the fuel gas regulation structure (not shown in the figure); in the injection hole array, the diameters of the injection holes in different circumferential sub-arrays can be different, and the numbers of the injection holes in different circumferential sub-arrays can be different, so as to realize on-demand injection of the small-molecule gel oxidant and improve the engine combustion efficiency; the flow-around plate 5 is arranged in the flow-around section 13 to strengthen heat dissipation.

[0036] The small-molecule gel oxidant has the characteristics of precise flow regulation, flowable heat dissipation and zoned injection, and is used for staged combustion with the solid fuel gas in the engine combustion chamber to increase the residence time and the turbulence degree of the oxidant and the fuel in the combustion chamber and improve the engine combustion efficiency.

Claims

1. A small molecule gel oxidizer sink-in staged combustion injector characterized by, The cylindrical inlet, the conical section, the flow-around section, the straight section, the axial connecting section and the radial connecting section are sequentially connected; The conical section, the flow-around section and the straight section are double-layer structures; the outer wall of the conical section, the outer wall of the flow-around section and the outer wall of the straight section are sequentially connected to form an outer wall, and the outer wall is connected with the cylindrical inlet and the axial connecting section at two ends respectively; The inner wall of the conical section, the inner wall of the flow-around section and the inner wall of the straight section are sequentially connected to form an inner wall, and the inner wall is closed at one end and connected with the outer wall at the other end; The cavity between the outer wall and the inner wall and the cylindrical inlet form an oxidant chamber; The cavity enveloped by the inner wall forms a fuel secondary combustion chamber, and the fuel secondary combustion chamber is through the axial connecting section; The conical section is internally provided with a fuel gas passage, and the fuel gas passage is through the fuel secondary combustion chamber; The inner wall is provided with an array of injection holes; The outer wall and the inner wall of the conical section are both provided with a plurality of fan-shaped flow-through holes, the fan-shaped flow-through holes on the inner wall are opposite to the fan-shaped flow-through holes on the outer wall; a plurality of channels are arranged between the outer wall and the inner wall of the conical section, the channels are used for connecting the fan-shaped flow-through holes on the outer wall and the fan-shaped flow-through holes on the inner wall, and the channels form the fuel gas passage; The outer wall of the flow-around section is outwardly convex, and the inner wall of the flow-around section is provided with a flow-around plate, and the flow-around plate is located between the outer wall of the flow-around section and the inner wall of the flow-around section.

2. The small molecule gel oxidant submerged staged combustion injector as described in claim 1, characterized in that, The fuel gas passages are uniformly arranged along the circumference.

3. The small molecule gel oxidant submerged staged combustion injector as described in claim 1, characterized in that, The array of injection holes is provided with a plurality of injection hole annular sub-arrays along the axial direction of the straight section, and the injection holes in each annular sub-array are uniformly arranged along the circumference of the straight section.

4. The submerged staged combustion injector for small molecule gel oxidants as described in claim 3, characterized in that, The diameters of the injection holes in different annular sub-arrays are not completely the same, and the number of the injection holes in different annular sub-arrays is not completely the same.

5. The submerged staged combustion injector for small molecule gel oxidants as described in claim 1, characterized in that, The axial connecting section is perpendicular to the radial connecting section, and a transition round corner is processed at the connection between the axial connecting section and the radial connecting section.

6. The small molecule gel oxidant submerged staged combustion injector as described in claim 1, characterized in that, The cylindrical inlet, the conical section, the flow-around section and the straight section are formed by 3D printing, the axial connecting section and the radial connecting section are integrally formed by machining, and the outer wall of the straight section is welded with the axial connecting section.

7. The small molecule gel oxidant submerged staged combustion injector as described in claim 1, characterized in that, According to the ignition sequence of the engine, the solid fuel is ignited and combusted to generate fuel-rich gas, the fuel-rich gas enters the fuel secondary combustion chamber through the fuel gas passage, the liquefied small molecule gel oxidant enters the oxidant chamber from the cylindrical inlet, the oxidant takes away the heat of the inner wall and the outer wall, and is sprayed from the injection holes of the array of injection holes into the fuel secondary combustion chamber to be mixed and combusted with the fuel-rich gas.

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