Submerged staged combustion injector for small molecule gel oxidant

Abstract

The submerged staged combustion injector for the small molecule gel oxidizing agent comprises a cylindrical inlet, a conical section, a streaming section, a straight section, an axial connecting section and a radial connecting section which are connected in sequence, the conical section, the streaming section and the straight section are each of a double-layer structure. The outer walls of the conical section, the streaming section and the straight section are sequentially connected to form an outer wall, and the two ends of the outer wall are connected with the cylindrical inlet and the axial connecting section respectively; the inner walls of the conical section, the streaming section and the straight section are sequentially connected to form an inner wall, one end of the inner wall is closed, and the other end is connected with the outer wall; an oxidant chamber is formed by a cavity between the outer wall and the inner wall and the cylindrical inlet; a cavity enveloped by the inner wall forms a secondary fuel combustion chamber; a fuel gas channel is arranged in the conical section and is communicated with the fuel secondary combustion chamber; and an injection hole array is formed in the inner wall. The residence time and the turbulence degree of an oxidizing agent and fuel in the combustion chamber are increased, staged combustion is achieved, and the combustion efficiency of the engine is improved.

Description

Technical Field

[0001] The invention relates to the field of aerospace propulsion, and in particular to a small molecule gel oxidant submersible staged combustion injector. Background Art

[0002] Red smoke nitric acid is a mixture of nitrogen tetroxide and nitric acid. It has the characteristics of low freezing point, high boiling point and high density. It is an oxidizer used in liquid rocket engines. In order to improve the long-term storage performance of liquid oxidizers and reduce the harm caused by accidental leakage, small molecule solidification factors are added to red smoke nitric acid to change the oxidizer from liquid to solid, avoiding the pre-packaging and leakage risks of existing liquid propellants. At the same time, it can be transformed 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 control device.

[0003] The injectors used in existing solid fuel and liquid oxidizer engines generally inject oxidizer at the head, and the combustion gas generated by the combustion of the solid fuel inner hole is mixed with the oxidizer injected at the head for combustion. In this combustion mode, the oxidizer is highly concentrated at the head and gradually decreases toward the nozzle, resulting in uneven retreat of the solid fuel combustion surface and low engine fuel efficiency, which has become a major difficulty restricting the development of solid fuel and liquid oxidizer mixed combustion engine technology. Summary of the invention

[0004] The purpose of the present invention is to provide a small molecule gel oxidant submersible staged combustion injector to solve the problems of unreasonable concentration distribution after oxidant injection, uneven solid fuel combustion surface retreat, low combustion efficiency, etc. in existing solid fuel and liquid oxidant mixed combustion engines.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a small molecule gel oxidant submerged staged combustion injector, comprising a cylindrical inlet, a conical section, a flow section, a straight section, an axial connecting section and a radial connecting section connected in sequence; the conical section, the flow section and the straight section are all double-layer structures; the outer wall of the conical section, the outer wall of the flow section and the outer wall of the straight section are connected in sequence to form an outer wall, and the two ends of the outer wall are respectively connected to the cylindrical inlet and the axial connecting section; the inner wall of the conical section, the inner wall of the flow section and the inner wall of the straight section are connected in sequence to form an inner wall, one end of the inner wall is closed, and the other end is connected to the outer wall; the cavity between the outer wall and the inner wall and the cylindrical inlet constitute an oxidant chamber; the cavity enclosed by the inner wall constitutes a fuel secondary combustion chamber, and the fuel secondary combustion chamber is connected with the axial connecting section; a fuel gas channel is provided in the conical section, and the fuel gas channel is connected with the fuel secondary combustion chamber; an injection hole array is provided on the inner wall.

[0006] The above-mentioned small molecule gel oxidizer submerged staged combustion injector, wherein a plurality of fan-shaped flow holes are provided on the outer wall and the inner wall of the conical section, and the fan-shaped flow holes on the inner wall are opposite to the fan-shaped flow holes on the outer wall one by one; a plurality of channels are provided between the outer wall and the inner wall of the conical section, and the channels are used to connect the fan-shaped flow holes on the opposite outer wall with the fan-shaped flow holes on the inner wall to form a fuel gas channel.

[0007] In the above-mentioned small molecule gel oxidizer submerged staged combustion injector, the fuel gas channels are evenly arranged along the circumference.

[0008] The above-mentioned small molecule gel oxidizer submerged staged combustion injector, wherein the injection hole array is provided with a plurality of annular subarrays of injection holes along the axial direction of the straight section, and the injection holes in each annular subarray are evenly arranged along the circumference of the straight section.

[0009] In the above-mentioned small molecule gel oxidizer submerged staged combustion injector, the diameters of the injection holes in different annular subarrays are not completely the same; the numbers of the injection holes in different annular subarrays are not completely the same.

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

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

[0012] The above-mentioned small molecule gel oxidizer submerged staged combustion injector, wherein 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 processed with a transition fillet.

[0013] The above-mentioned small molecule gel oxidizer submerged staged combustion injector, wherein the cylindrical inlet, the conical section, the flow section and the straight section are formed by 3D printing, the axial connecting section and the radial connecting section are machined into one piece, and the outer wall of the straight section is welded to the axial connecting section.

[0014] The above-mentioned small molecule gel oxidizer submerged staged combustion injector, in which solid fuel is ignited and burned according to the engine ignition timing to produce fuel-rich combustion gas, and the fuel-rich combustion gas enters the fuel secondary combustion chamber through the fuel combustion gas channel; the liquefied small molecule gel oxidizer enters the oxidizer chamber from the cylindrical inlet, and the oxidizer takes away the heat from the inner and outer walls, and at the same time is ejected from the injection holes of the injection hole array, enters the fuel secondary combustion chamber, and is mixed and burned with the fuel-rich combustion gas.

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

[0016] (1) The small molecule gel oxidant can be transported into the combustion chamber and injected according to the axial concentration distribution of the fuel gas, which significantly improves the mixing turbulence of the fuel gas and the oxidant, and is beneficial to improving the combustion efficiency of the engine;

[0017] (2) It can work together with the fuel gas flow regulating structure to adjust the fuel gas flow, achieve the best oxygen-fuel ratio combustion with the oxidizer, and realize engine thrust regulation and efficient combustion;

[0018] (3) The small molecule gel oxidant turns into liquid after flowing. The efficient heat exchange capacity of the liquid is used to provide thermal protection for the injector structure, guide the solid fuel gas from the front end to the rear end of the engine, increase the residence time of the oxidant and fuel gas in the combustion chamber, and improve the combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The small molecule gel oxidant submersible staged combustion injector of the present invention is given by the following embodiments and drawings.

[0020] Figure 1 This is a schematic diagram of the appearance of a small molecule gel oxidizer submerged staged combustion injector according to an embodiment of the present invention.

[0021] Figure 2 It is a cross-sectional view and a partially enlarged view of a small molecule gel oxidizer submerged staged combustion injector according to an embodiment of the present invention.

[0022] Figure 3 It is a partial enlarged view of the conical section in the embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined Figure 1 to Figure 3 The small molecule gel oxidant submerged staged combustion injector of the present invention is further described in detail.

[0024] Figure 1 Shown is a schematic diagram of the appearance of a small molecule gel oxidant submersible staged combustion injector according to an embodiment of the present invention; Figure 2 Shown are a cross-sectional view and a partially enlarged view of a small molecule gel oxidizer submerged staged combustion injector according to an embodiment of the present invention.

[0025] Combination Figure 1 and Figure 2 The small molecule gel oxidant submerged staged combustion injector of this embodiment comprises a cylindrical inlet 1, a conical section 12, a flow-around section 13, a straight section, an axial connection section 2 and a radial connection section 3 which are connected in sequence;

[0026] The conical section 12, the bypass 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 bypass section 13 and the outer wall 9 of the straight section are connected in sequence to form an outer wall, and the two ends of the outer wall are respectively connected to the cylindrical inlet 1 and the axial connecting section 2. Specifically, the cylindrical inlet 1 is connected to the outer wall of the conical section 12, and the axial connecting section 2 is connected to the outer wall 9 of the straight section; the inner wall of the conical section 12, the inner wall of the bypass section 13 and the inner wall 6 of the straight section are connected in sequence to form an inner wall, and one end of the inner wall is closed and the other end is connected to the outer wall. Specifically, the end of the inner wall of the conical section 102 that is not connected to the inner wall of the bypass section is closed, and the end of the inner wall 6 of the straight section that is not connected to the inner wall of the bypass section is connected to the outer wall 9 of the straight section (see Figure 2 Middle partial enlargement);

[0027] like Figure 1 and Figure 3 , a plurality of fan-shaped flow holes 10 are provided on both the outer wall 15 and the inner wall 16 of the tapered section 102, and the plurality of fan-shaped flow holes 10 are evenly arranged along the circumference, and the fan-shaped flow holes on the inner wall 16 are opposite to the fan-shaped flow holes on the outer wall 15 one by one, that is, the number of the fan-shaped flow holes on the inner wall 16 is equal to the number of the fan-shaped flow holes on the outer wall 15, and the arrangement positions of the fan-shaped flow holes on the inner wall 16 coincide with the arrangement positions of the fan-shaped flow holes on the outer wall 15; a plurality of channels 17 are provided between the outer wall 15 and the inner wall 16 of the tapered section 102, and the channels 17 are used to connect the fan-shaped flow holes on the opposite outer wall 15 with the fan-shaped flow holes on the inner wall 16 to form fuel gas channels;

[0028] like Figure 2 , an injection hole array is provided on the inner wall 6 of the straight section. In this embodiment, a plurality of annular subarrays of injection holes are arranged along the axial direction of the straight section, and the injection holes in each annular subarray are evenly arranged along the circumference of the straight section; the diameters of the injection holes in different annular subarrays may be different, such as the diameter of the injection hole I7 is 0.4 mm, and the diameter of the injection hole II8 is 0.6 mm; the number of injection holes in different annular subarrays may be different, such as the annular subarray where the injection hole I7 is located includes 24 injection holes, and the annular subarray where the injection hole II8 is located includes 20 injection holes;

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

[0030] The cavity surrounded by the inner wall forms a fuel secondary combustion chamber 11 , which is connected to the axial connecting section 2 .

[0031] like Figure 2The outer wall 4 of the flow bypass section 13 protrudes outward, and a flow bypass plate 5 is provided on the inner wall of the flow bypass section 13 . The flow bypass plate 5 is located between the outer wall 4 of the flow bypass section 13 and the inner wall of the flow bypass section 13 .

[0032] In this 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 thickness 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 (that is, the two are 90°), and the connection between the axial connecting section 2 and the radial connecting section 3 is processed with a transition fillet; 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 submersible staged combustion injector of this embodiment is as follows:

[0034] The solid fuel is ignited and burned according to the engine ignition sequence to generate fuel-rich gas, which enters the fuel secondary combustion chamber 11 through the fuel gas channel (composed of fan-shaped flow holes and channel 17); the oxidant delivery system provides pressure to extrude the oxidant, and the liquefied small molecule gel oxidant enters the oxidant chamber 14 from the cylindrical inlet 1. The oxidant takes away the heat from the inner wall and the outer wall, and is ejected from the injection holes of the injection hole array, enters the fuel secondary combustion chamber 11, and is mixed and burned with the fuel-rich gas;

[0035] A bypass section 13 is provided between the conical section 12 and the straight section, and is used to realize gas flow regulation together with the gas regulating structure (not shown in the figure); in the injection hole array, the injection hole diameters in different annular sub-arrays may be different, and the number of injection holes in different annular sub-arrays may be different, so as to realize the on-demand injection of small molecule gel oxidant and improve the engine combustion efficiency; a bypass plate 5 is provided in the bypass section 13 to enhance heat dissipation.

[0036] The present invention utilizes the characteristics of precise flow control, flowable heat dissipation, and zoned injection of small molecule gel oxidant to perform staged combustion with solid fuel gas in the engine combustion chamber, increase the residence time and turbulence degree of the oxidant and fuel in the combustion chamber, and improve the engine combustion efficiency.

Claims

1. Small molecule gel oxidant submersible staged combustion injector, characterized in that: It includes a cylindrical inlet, a conical section, a flow-around section, a straight section, an axial connecting section and a radial connecting section which are connected in sequence; The conical section, the flow-around section and the straight section are all 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 two ends of the outer wall are respectively connected to the cylindrical inlet and the axial connecting section; The inner wall of the conical section, the inner wall of the bypass section, and the inner wall 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 to the outer wall; The cavity between the outer wall and the inner wall and the cylindrical inlet constitute an oxidant chamber; The cavity surrounded by the inner wall forms a fuel secondary combustion chamber, and the fuel secondary combustion chamber is connected with the axial connecting section; A fuel gas channel is provided in the conical section, and the fuel gas channel is connected to the fuel secondary combustion chamber; An injection hole array is provided on the inner wall.

2. The small molecule gel oxidant submersible staged combustion injector as claimed in claim 1, characterized in that: A plurality of fan-shaped flow holes are provided on the outer wall and the inner wall of the tapered section, and the fan-shaped flow holes on the inner wall are opposite to the fan-shaped flow holes on the outer wall one by one; a plurality of channels are provided between the outer wall and the inner wall of the tapered section, and the channels are used to connect the fan-shaped flow holes on the opposite outer wall with the fan-shaped flow holes on the inner wall to form a fuel gas channel.

3. The small molecule gel oxidant submersible staged combustion injector as claimed in claim 2, characterized in that: The fuel gas channels are evenly arranged along the circumference.

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

5. The small molecule gel oxidant submersible staged combustion injector as claimed in claim 4, characterized in that: The diameters of the injection holes in different annular subarrays are not completely the same; the numbers of the injection holes in different annular subarrays are not completely the same.

6. The small molecule gel oxidant submersible staged combustion injector as claimed in claim 1, characterized in that: The outer wall of the flow bypass section bulges outwards.

7. The small molecule gel oxidant submersible staged combustion injector as claimed in claim 6, characterized in that: A flow bypass plate is provided on the inner wall of the flow bypass section, and the flow bypass plate is located between the outer wall of the flow bypass section and the inner wall of the flow bypass section.

8. The small molecule gel oxidant submersible staged combustion injector as claimed in claim 1, characterized in that: The axial connecting section is perpendicular to the radial connecting section, and a transition fillet is processed at a connection between the axial connecting section and the radial connecting section.

9. The small molecule gel oxidant submersible staged combustion injector as claimed 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 to the axial connecting section.

10. The small molecule gel oxidant submersible staged combustion injector as claimed in claim 1, characterized in that: The solid fuel is ignited and burned according to the engine ignition sequence to generate fuel-rich combustion gas, which enters the fuel secondary combustion chamber through the fuel combustion gas channel; the liquefied small molecule gel oxidant enters the oxidant chamber from the cylindrical inlet, and the oxidant takes away the heat from the inner and outer walls, and is ejected from the injection holes of the injection hole array, enters the fuel secondary combustion chamber, and is mixed and burned with the fuel-rich combustion gas.

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