A bubble jet injector of the assembly structure type

Abstract

The present application relates to the technical field of injector, aiming at solving the problem that the state of combustion heater is multiple, the existing injector is a whole or welded structure, which is not conducive to the inflow parameter adjustment of the combustion heater, providing a bubble nozzle injector with an assembly structure, comprising a bubble gas cover plate, a fuel cavity panel and an oxidant panel arranged in sequence from top to bottom, which are assembled into a whole; the top of the bubble gas cover plate is provided with an air inlet, and the bubble gas cover plate is provided with a gas cavity; the fuel cavity panel is provided with a fuel cavity, and the fuel cavity panel is detachably connected with a bubble nozzle and a fuel nozzle, one end of the bubble nozzle is communicated with the gas cavity, and the other end of the bubble nozzle is inserted into the fuel nozzle; one end of the fuel nozzle is communicated with the fuel cavity, and the other end of the fuel nozzle is inserted into a through hole formed in the oxidant panel and is flush with the oxidant panel; the oxidant panel is provided with an oxidant cavity and an oxidant injection hole, and the oxidant injection hole is arranged around the through hole.

Description

Technical Field

[0001] This invention relates to the field of injector technology, and more specifically, to a bubble nozzle injector with an assembled structure. Background Technology

[0002] With the advancement and deepening of hypersonic vehicle research, air heaters, as ground-based testing equipment, have been widely used in the aerospace field both domestically and internationally. Air heaters are devices that heat air to achieve the simulated test conditions. Based on different heating methods, they can be classified into four types: combustion heating, electric arc heating, regenerative heating, and shock tube heating. Among these, combustion heating air heaters are the most widely used testing equipment for hypersonic vehicle ground-based testing. Combustion heaters utilize the combustion of fuel and oxidizer within the heater's combustion chamber to heat the air, generating a high-temperature airflow at the device outlet with specific total temperature, total pressure, and flow rate requirements.

[0003] In terms of the form of the oxidant and fuel involved in combustion, combustion heaters mainly use two types of fuel: gaseous fuels such as hydrogen and methane, and liquid fuels such as kerosene, alcohol, and isobutane. Compared with gaseous fuels, using liquid fuels can reduce storage space, lower testing costs, and offer better safety. Therefore, combustion heaters using liquid fuels are becoming increasingly widely used.

[0004] The use of liquid fuels necessitates the use of a high-quality atomization device to ensure rapid atomization, evaporation, and thorough mixing with oxidants such as oxygen-enriched air. The primary function of the injector is to atomize and mix the fuel and oxidant, and the nozzle is the key component for achieving this. Due to its advantages such as low energy consumption, excellent atomization effect, and wide applicability, the bubble atomizing nozzle can be used in combustion heater injectors. Liquid fuel is injected into the combustion chamber through the nozzle, atomized within the chamber, and after the droplets evaporate, rapidly mix with air to form a combustible mixture, ensuring the effective start-up of the combustion heater.

[0005] To ensure that there is no cross-contamination between the oxidizer collection chamber and the fuel collection chamber, injectors are currently mostly assembled by welding, resulting in a welded structure, either entirely or partially. However, for combustion heaters used in ground tests, which have numerous state parameters and require reusability, an integral or welded structure cannot meet the needs of different test conditions simply by adjusting parameters such as nozzle pressure drop. Furthermore, if a single nozzle is damaged, the entire injector must be scrapped. Both of these situations require replacement of the entire injector, which significantly increases test costs and reduces test efficiency. This is especially true for exploratory tests, which have a wide range of incoming flow parameter requirements and require frequent parameter adjustments. The long processing time for the injector leads to a prolonged test cycle and low utilization of the test equipment. Summary of the Invention

[0006] The present invention aims to provide a bubble nozzle injector with an assembled structure to solve the problems of existing combustion heaters having multiple states and existing injectors being integral or welded structures, which are not conducive to the adjustment of combustion heater inflow parameters, resulting in high test costs and low test efficiency.

[0007] This invention is achieved using the following technical solution:

[0008] The present invention provides a bubble nozzle injector with an assembled structure, comprising a bubble gas cover plate, a fuel chamber panel and an oxidant panel arranged sequentially from top to bottom, which are assembled into a whole;

[0009] The top of the bubble gas cover is provided with an air inlet, and the bubble gas cover is provided with a gas chamber; the fuel chamber panel is provided with a fuel chamber, and a bubble nozzle and a fuel nozzle are detachably connected to the fuel chamber panel. One end of the bubble nozzle is connected to the gas chamber, and the other end of the bubble nozzle is inserted into the fuel nozzle; one end of the fuel nozzle is connected to the fuel chamber, and the other end of the fuel nozzle is inserted into a through hole opened on the oxidant panel and is flush with the oxidant panel;

[0010] The oxidant panel is provided with an oxidant cavity and oxidant spray holes, with the oxidant spray holes arranged around the through hole.

[0011] This invention employs a bubble atomizing nozzle as the liquid fuel atomizing device. Different sizes and structures of bubble atomizing nozzles can be replaced according to the test flow requirements, providing a wide range of injection flow rate adjustment capabilities to meet the needs of different test conditions. This invention can provide a wide range of fuel flow rates to meet the flow parameter requirements of different test conditions. It features convenient replacement, easy maintenance, cost savings, and improved test efficiency, making it suitable for engineering applications in combustion heaters.

[0012] As a preferred technical solution:

[0013] Pressure measuring conduits are provided on the gas bubble cover, the fuel chamber panel, and the oxidant panel, and the pressure measuring conduits are used to measure the chamber pressure of the corresponding chamber.

[0014] As a preferred technical solution:

[0015] Pressure measuring holes are provided on the gas bubble cover, the fuel chamber panel, and the oxidant panel. The pressure measuring holes are connected to the corresponding chambers, and the pressure measuring conduits are installed in the corresponding pressure measuring holes.

[0016] As a preferred technical solution:

[0017] The oxidant panel is provided with an oxidant inlet, which is connected to the oxidant chamber.

[0018] As a preferred technical solution:

[0019] The fuel chamber panel is provided with a fuel inlet, which is connected to one end of the fuel chamber and the other end of the fuel chamber is connected to the fuel nozzle. The fuel inlet is used to supply fuel to the fuel nozzle.

[0020] As a preferred technical solution:

[0021] The fuel chamber panel is provided with a plurality of fuel chambers, one end of each fuel chamber is connected to a fuel nozzle, and the other end of each fuel chamber is connected to a fuel inlet.

[0022] As a preferred technical solution:

[0023] The opening direction of each of the fuel chambers is consistent.

[0024] As a preferred technical solution:

[0025] The bubble nozzle, the fuel nozzle, and the fuel chamber panel are connected by threads.

[0026] As a preferred technical solution:

[0027] A sealing ring is provided between the bubble nozzle and the fuel chamber panel, and between the fuel nozzle and the fuel chamber panel.

[0028] As a preferred technical solution:

[0029] The oxidant nozzle includes a plurality of circular holes arranged around the through hole.

[0030] After the fuel nozzle is installed, an annular gap can be formed between it and the through hole on the oxidant panel. The oxidant can also flow through this annular gap. Therefore, after the fuel nozzle is installed, the inner diameter of the annular gap can be changed due to the different sizes of the fuel nozzles, thereby changing the oxidant flow area and adjusting the oxidant flow rate.

[0031] As a preferred technical solution:

[0032] The gas bubble cover and the fuel chamber panel, as well as the fuel chamber panel and the oxidant panel, are detachably connected.

[0033] As a preferred technical solution:

[0034] A sealing ring is provided between the gas bubble cover and the fuel chamber panel, and between the fuel chamber panel and the oxidant panel.

[0035] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] 1. This invention modularizes the components of the injector and adopts an assembly structure, which facilitates the replacement of key components such as nozzles. Depending on the different test conditions of the combustion heater, nozzles of different sizes and structures can be assembled, which greatly increases the injection flow range of the injector without replacing the entire injector, and is beneficial for adjusting the injector parameters. At the same time, it solves the problem that the entire injector will be scrapped if a single nozzle is damaged, saving test costs, reducing the test cycle, and increasing test efficiency.

[0037] 2. This invention adjusts the gas-liquid ratio by adjusting the air pressure of the bubbles and changing the bubble nozzles of different sizes.

[0038] 3. The present invention adjusts the fuel flow rate by replacing fuel nozzles of different sizes and shapes.

[0039] 4. This invention adjusts the oxidant flow area by changing the inner diameter of the annular gap (i.e., the outer diameter of the fuel nozzle) by replacing the fuel nozzle, and by changing the outer diameter of the annular gap, the diameter of the circular hole, and the number of a set of circular holes by changing the oxidant panel, thereby further adjusting the oxidant flow rate.

[0040] 5. This invention enables pressure monitoring and flow control.

[0041] 6. The injector provided by this invention has the characteristics of convenient replacement, easy maintenance, cost saving and high stability, which makes it easy to be applied in the engineering of combustion heaters. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the assembly structure of the bubble nozzle injector described in this invention.

[0043] Figure 2 This is a schematic diagram of the structure of the fuel chamber panel described in this invention.

[0044] Figure 3 This is a schematic diagram of the structure of the bubble nozzle described in this invention.

[0045] Figure 4 This is a schematic diagram of the structure of the fuel nozzle described in this invention.

[0046] Figure 5 This is a schematic diagram of the structure of the fuel nozzle end orifice of the present invention, which is a circular hole.

[0047] Figure 6 This is a schematic diagram of the structure of the fuel nozzle end orifice of the present invention, which is a square hole.

[0048] Figure 7 This is a schematic diagram of the structure of the fuel nozzle end orifice of the present invention, which is an elliptical orifice.

[0049] Figure 8 This is a schematic diagram of the oxidant flow area.

[0050] Icons: 1-Oxidizer panel, 2-Oxidizer inlet, 3-Fuel chamber panel, 4-Bubble gas cover, 5-Oxidizer chamber, 6-O-ring seal, 7-Gas chamber, 8-Third pressure measuring conduit, 9-Air inlet, 10-First sealing ring, 11-Bubble nozzle, 12-Fuel nozzle, 13-Second sealing ring, 14-Second pressure measuring conduit, 15-Fuel chamber, 16-Oxidizer nozzle, 17-First pressure measuring conduit, 18-Fuel inlet. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Example 1

[0053] like Figure 1 As shown, this embodiment proposes a bubble nozzle injector with an assembly structure, including an oxidant panel 1, a fuel chamber panel 3, a bubble gas cover 4, a bubble nozzle 11, and a fuel nozzle 12.

[0054] The oxidant panel 1 is provided with an oxidant inlet 2, an oxidant chamber 5, an oxidant nozzle 16, and a first pressure measuring conduit 17. In this embodiment, the oxidant chamber 5 is located in the middle of the oxidant panel 1; the oxidant inlet 2 is located on one side of the oxidant panel 1 and is connected to the oxidant chamber 5; a pressure measuring hole is provided on the oxidant panel 1 and is connected to the oxidant chamber 5. The first pressure measuring conduit 17 is installed in the pressure measuring hole and is used to measure the pressure in the oxidant chamber 5; the oxidant nozzle 16 is provided at the bottom of the oxidant panel 1 and is also connected to the oxidant chamber 5.

[0055] The fuel chamber panel 3 is provided with a second pressure measuring conduit 14, a fuel chamber 15, and a fuel inlet 18. In this embodiment, one end of the fuel chamber 15 is connected to the fuel nozzle 12, and the other end of the fuel chamber 15 is connected to the fuel inlet 18. The fuel chamber panel 3 is also provided with a pressure measuring hole, which is connected to the fuel chamber 15. The second pressure measuring conduit 14 is installed in the pressure measuring hole and is used to measure the pressure in the fuel chamber 15.

[0056] The bubble gas cover plate 4 is provided with a gas chamber 7, a third pressure measuring conduit 8, and an air inlet 9. In this embodiment, the air inlet 9 is opened at the top of the bubble gas cover plate 4 and is connected to the gas chamber 7. The top of the bubble gas cover plate 4 is also provided with a pressure measuring hole, and the third pressure measuring conduit 8 is installed in the pressure measuring hole. The third pressure measuring conduit 8 is used to measure the pressure in the gas chamber 7.

[0057] In this embodiment, the bubble gas cover plate 4, the fuel chamber panel 3, and the oxidant panel 1 are arranged sequentially from top to bottom and assembled into a whole. The bubble gas cover plate 4 and the fuel chamber panel 3, and the fuel chamber panel 3 and the oxidant panel 1 are sealed by O-rings 6.

[0058] The bubble nozzle 11 and the fuel nozzle 12 are respectively connected to the fuel chamber panel 3 by threads. The bubble nozzle 11 and the fuel chamber panel 3 are sealed with a first sealing ring 10, and the fuel nozzle 12 and the fuel chamber panel 3 are sealed with a second sealing ring 13.

[0059] One end of the bubble nozzle 11 is connected to the gas chamber 7, and the other end of the bubble nozzle 11 is inserted into the fuel nozzle 12; one end of the fuel nozzle 12 is connected to the fuel chamber 15, and the other end of the fuel nozzle 12 is inserted into the through hole on the oxidant panel 1 and is flush with the oxidant panel 1.

[0060] A plurality of small circular holes are arranged around the through hole, which serve as the oxidant spray holes 16. After the fuel nozzle 12 is installed in the through hole, when the outer diameter of the fuel nozzle 12 is smaller than the diameter of the through hole, an annular gap can be formed between the fuel nozzle 12 and the through hole. This annular gap can also allow oxidant to flow. Therefore, after the fuel nozzle 12 is installed, the inner diameter of the annular gap can be changed due to the different sizes of the fuel nozzle 12, thereby changing the oxidant flow area and adjusting the oxidant flow rate. Figure 6 As shown in the figure, the gray shaded area is the annular gap, and the circular hole around it is the small circular hole.

[0061] The injector of the present invention is connected to the combustion chamber through bolt holes on the bubble gas cover plate 4.

[0062] The aforementioned pressure measuring conduit can measure the corresponding cavity pressure, which can accurately control the nozzle flow rate and prevent overpressure, thus ensuring equipment safety.

[0063] like Figure 2 As shown, the fuel chamber panel 3 has three parallel fuel chambers 15. One end of each fuel chamber 15 is connected to a fuel nozzle 12, and the other end of each fuel chamber 15 is connected to a fuel inlet 18. The three fuel inlets 18 supply fuel to the three fuel nozzles 12 respectively, and the three fuel inlets 18 are oriented in the same direction, which reduces the impact of positional differences on nozzle performance. Simultaneously, pressure measuring holes connect the three fuel chambers 15, ensuring consistent fuel supply pressure and reducing nozzle flow error.

[0064] The airflow rate of the bubbles can be adjusted by replacing different bubble nozzles 11. The structure of the bubble nozzle 11 is as follows: Figure 3 As shown, the area of ​​the gas nozzle is:

[0065] S1=π*d 2 / 4*N

[0066] in:

[0067] S1—Total area of ​​the gas nozzle;

[0068] d — diameter of the gas nozzle;

[0069] N – The number of gas nozzles;

[0070] The formula for calculating gas flow rate is:

[0071]

[0072] in:

[0073] g oh —Gas flow rate, kg / s;

[0074] μ—flow coefficient;

[0075] S1—Total area of ​​the gas nozzle;

[0076] P0—Inlet pressure of the bubble nozzle;

[0077] k — gas specific heat ratio;

[0078] P c — Combustion chamber pressure;

[0079] T—Gas temperature;

[0080] R—gas constant.

[0081] Therefore, the gas-liquid ratio can be adjusted by replacing bubble nozzles 11 with different numbers and orifice diameters to meet the flow requirements of different test conditions.

[0082] The structure of the fuel nozzle 12 is as follows: Figure 4 As shown, the fuel flow rate can be adjusted by replacing the fuel nozzle 12 with different nozzle sizes and shapes. Figures 5-7 As shown, the shape of the nozzle at the end of the fuel nozzle 12 can be a round hole, a square hole, an elliptical hole, etc. Changing the shape of the nozzle can not only change the flow rate and atomization performance, but also the flow coefficient and spray performance: square hole > elliptical hole > round hole; and different fuel flow rates can be obtained by changing the size of the nozzle.

[0083] The formula for calculating fuel flow rate is:

[0084] m f =C d S2(2ρΔP) 0.5

[0085] in:

[0086] m f —Fuel flow rate;

[0087] C d —Fuel injection orifice flow coefficient;

[0088] S2—Fuel injection orifice area;

[0089] ρ — fuel density;

[0090] △P——Injection pressure drop.

[0091] like Figure 8 As shown, the total flow area of ​​the oxidant is the sum of the areas of the annular gap and the surrounding small circular holes in the diagram. The calculation method is as follows:

[0092] S3=(π(D 12 -D2 2 ) / 4+π*d 12 / 4*n1)*n2

[0093] in:

[0094] S3—Total area of ​​oxidant nozzles;

[0095] D1—Outer diameter of the annular gap;

[0096] D2—Inner diameter of the annular gap (i.e., outer diameter of the fuel nozzle);

[0097] d1—Diameter of the small circular hole;

[0098] n1 — the number of small round holes in a set;

[0099] n2 — the number of fuel nozzles, which is 3 in this embodiment. This embodiment takes a three-nozzle injector as an example.

[0100] Therefore, the oxidant flow area can be adjusted by changing the inner diameter D2 of the annular gap (i.e., the outer diameter of the fuel nozzle 12) by replacing the fuel nozzle 12, and by changing the outer diameter D1 of the annular gap, the diameter d1 of the small round hole, and the number n1 of a set of small round holes by replacing the oxidant panel 1, thereby further adjusting the oxidant flow rate.

[0101] This invention provides a bubble nozzle injector with an assembled structure. The main components of this injector are all assembled, allowing for the installation of nozzles of different sizes and structures to suit different test conditions of the combustion heater. This significantly increases the injection flow rate range of the injector without requiring a complete replacement. It also solves the problem of the entire injector becoming unusable if a single nozzle fails, reducing testing costs, shortening the testing cycle, and increasing testing efficiency. This injector features convenient replacement, easy maintenance, cost savings, and high stability, making it suitable for engineering applications in combustion heaters.

[0102] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bubble nozzle injector with an assembled structure, characterized in that: It includes a bubble gas cover, a fuel chamber panel, and an oxidizer panel arranged from top to bottom, which are assembled into a whole; The top of the bubble gas cover is provided with an air inlet, and the bubble gas cover is provided with a gas chamber; the fuel chamber panel is provided with a fuel chamber, and a bubble nozzle and a fuel nozzle are detachably connected to the fuel chamber panel. One end of the bubble nozzle is connected to the gas chamber, and the other end of the bubble nozzle is inserted into the fuel nozzle; one end of the fuel nozzle is connected to the fuel chamber, and the other end of the fuel nozzle is inserted into a through hole opened on the oxidant panel and is flush with the oxidant panel; an annular gap is formed between the fuel nozzle and the through hole; The oxidant panel is provided with an oxidant cavity and oxidant spray holes, and the oxidant spray holes are arranged around the through hole; The oxidant panel is provided with an oxidant inlet, which is connected to the oxidant chamber. The fuel chamber panel is provided with a fuel inlet, which is connected to one end of the fuel chamber and the other end of the fuel chamber is connected to the fuel nozzle. The fuel inlet is used to supply fuel to the fuel nozzle. The oxidant spray hole includes a plurality of circular holes arranged around the through hole; The gas bubble cover and the fuel chamber panel, as well as the fuel chamber panel and the oxidant panel, are detachably connected.

2. The bubble nozzle injector with the assembly structure according to claim 1, characterized in that: Pressure measuring conduits are provided on the gas bubble cover, the fuel chamber panel, and the oxidant panel, and the pressure measuring conduits are used to measure the chamber pressure of the corresponding chamber.

3. The bubble nozzle injector with the assembly structure according to claim 2, characterized in that: Pressure measuring holes are provided on the gas bubble cover, the fuel chamber panel, and the oxidant panel. The pressure measuring holes are connected to the corresponding chambers, and the pressure measuring conduits are installed in the corresponding pressure measuring holes.

4. The bubble nozzle injector with the assembly structure according to claim 1, characterized in that: The bubble nozzle, the fuel nozzle, and the fuel chamber panel are connected by threads.

5. The bubble nozzle injector with the assembly structure according to claim 1, characterized in that: A sealing ring is provided between the bubble nozzle and the fuel chamber panel, and between the fuel nozzle and the fuel chamber panel.

6. The bubble nozzle injector with the assembly structure according to claim 1, characterized in that: A sealing ring is provided between the gas bubble cover and the fuel chamber panel, and between the fuel chamber panel and the oxidant panel.

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