A jet injection design method and nozzle with coaxial bubbles and plungers

Abstract

The present invention belongs to the field of engine combustion chambers and combustion heater devices, and discloses a jet injection design method and nozzle with coaxial bubbles and a pintle. The jet injection design method with coaxial bubbles and a pintle includes determining the technical solution; determining the technical functions of each module; determining the flow rate requirements of each module; and determining the processing method of the coaxial nozzle for bubbles and a pintle. The coaxial nozzle for bubbles and a pintle includes a bubble nozzle and a pintle nozzle with the same central axis. The pintle nozzle is sleeved outside the bubble nozzle, and the outlet of the bubble nozzle is located in the inner cavity of the pintle nozzle. The jet injection design method with coaxial bubbles and a pintle of the present invention adopts a compact layout and partitioned four-cavity design. The obtained coaxial nozzle for bubbles and a pintle has a simple and reliable structure, is light in weight, and has engineering practical value.

Description

Technical Field

[0001] The invention belongs to the field of engine combustion chambers and combustion heater devices, and in particular relates to a coaxial injection design method for bubbles and pintles and a nozzle. Background Art

[0002] The injector or nozzle is the core component in the combustion chamber for organizing the injection, atomization and combustion of fuel and oxidizer. Fixed cross-sectional area injectors are usually used in turbine gas turbines, liquid rocket engines, combustion heaters and other equipment to solve the problem of sufficient atomization of liquid fuel. For example, the combustion chamber of a turbine engine uses an air atomizing nozzle, and the atomization of its liquid fuel is more dependent on the supply of air and reasonable gas-liquid atomization organization; while liquid rocket engines often use coaxial nozzles, but because there is no large recirculation area design, it is difficult to adapt to large changes in the flow rate of fuel and oxidizer. Recently, the application of pintle nozzles in liquid rocket engines has received attention. It has a large recirculation area and a strong ability to adapt to changes in the flow rate of fuel and oxidizer, but it has problems such as insufficient ability to adapt to changes in the oil-gas ratio. Overall, the existing nozzles have the following objective deficiencies:

[0003] (1) For air atomizing nozzles, a large air flow rate is often required. Since many power units or combustion heaters are difficult to supply sufficient atomizing gas, it will be difficult to atomize, ignite and efficiently burn liquid fuel in the case of low atomizing gas;

[0004] (2) For coaxial nozzles, including coaxial direct current nozzles and coaxial centrifugal nozzles, the ability to adapt to large-scale changes in fuel and oxidant flow rates is weak, and they can usually only be used for fixed working conditions or small-range change working conditions;

[0005] (3) For the pintle nozzle, the ability to adapt to flow changes is stronger than that of the coaxial nozzle, but the combustion efficiency will deteriorate at too small a flow rate. For example, the combustion efficiency in an overly rich or oxygen-rich state drops from more than 96% of the main design point to 80% or even lower.

[0006] The above nozzles all need to be equipped with torch igniters or other high-energy devices to achieve wide-range reliable ignition and flame stabilization.

[0007] Currently, there is an urgent need to develop a coaxial injection design method and nozzle for the bubble and the pintle. Summary of the invention

[0008] One technical problem to be solved by the present invention is to provide a design method for injection with a bubble and a pintle coaxially. Another technical problem to be solved by the present invention is to provide a nozzle with a bubble and a pintle coaxially.

[0009] The bubble and pintle coaxial injection design method of the present invention comprises the following steps:

[0010] S10. Determine the technical solution;

[0011] Adopt a main and auxiliary double-module nozzle. The auxiliary module uses a bubble nozzle, and the main module uses a pin bolt nozzle. The two are coaxially injected;

[0012] S20. Determine the technical functions of each module;

[0013] The flow rate of the auxiliary module is less than that of the main module; the bubble nozzle of the auxiliary module realizes small-flow ignition and reliable combustion through bubble injection, and the pin bolt nozzle of the main module organizes combustion under large flow rates through pin bolt injection; the high-temperature gas generated by the combustion of the bubble-injected gas serves as the ignition and flame-stabilizing torch for the pin bolt-injected gas;

[0014] S30. Determine the flow rate requirements for each module;

[0015] The flow rate of the auxiliary module is 1 / 5 - 1 / 10 of the maximum total flow rate, which is used to achieve the mixing, atomization, injection, and combustion organization of liquid fuel and gas oxidant at a maximum flow rate ratio of 3:1; through numerical simulation calculations, it is found that if the mixing atomization is greater than 3%, the combustion efficiency of the auxiliary module is higher than 96% within the working range;

[0016] The minimum flow rate of the main module is 80% - 100% of the maximum flow rate of the auxiliary module, and the forms of annular slot and annular slot injection or annular slot and hole injection are adopted; through numerical simulation calculations, it is found that when the injection momentum ratio of liquid fuel and gas oxidant is (0.5 - 3.0):1, sufficient atomization is ensured; when the ratio d of the maximum working flow rate to the minimum working flow rate of the main module is greater than or equal to 5:1, the combustion efficiency is higher than 95%;

[0017] It is also found through numerical simulation calculations that if the flow rate ratio of the maximum flow rate of the main module to the minimum flow rate of the auxiliary module is greater than or equal to 25:1, the overall combustion efficiency is still higher than 95%;

[0018] S40. Determine the processing method of the bubble and pin bolt coaxial nozzle;

[0019] The bubble nozzle of the auxiliary module and the pin bolt nozzle of the main module are respectively manufactured by 3D additive manufacturing method; the auxiliary module and the main module have the same central axis. The auxiliary module is inserted into the main module from top to bottom, and the two are hermetically connected through a radial sealing ring and a thread connection to obtain a bubble and pin bolt coaxial nozzle.

[0020] The bubble and pin bolt coaxial nozzle of the present invention includes an auxiliary module and a main module with the same central axis. The auxiliary module is a bubble nozzle, and the main module is a pin bolt nozzle. The pin bolt nozzle is sleeved outside the bubble nozzle, and the outlet of the bubble nozzle is located inside the cavity of the pin bolt nozzle;

[0021] In the upper part of the bubble and pintle coaxial nozzle, the secondary mold and the main mold are separated in half by staggered manner to form two layers of four cavities; the upper layer is the fuel manifold cavity I and the oxidant manifold cavity I of the bubble nozzle of the secondary mold, which respectively provide liquid fuel and gaseous oxidant for the bubble nozzle; the lower layer is the fuel manifold cavity II and the oxidant manifold cavity II of the pintle nozzle of the main mold, which respectively provide liquid fuel and gaseous oxidant for the pintle nozzle; the fuel manifold cavity I and the oxidant manifold cavity II are opposite to each other in the upper and lower parts, and are located on the left side of the bubble and pintle coaxial nozzle; the oxidant manifold cavity I and the fuel manifold cavity II are opposite to each other in the upper and lower parts, and are located on the right side of the bubble and pintle coaxial nozzle;

[0022] The top of the bubble and pintle coaxial nozzle is provided with inlet pipes which are respectively connected with the fuel manifold chamber I and the oxidant manifold chamber I and the fuel manifold chamber II and the oxidant manifold chamber II.

[0023] Compared with traditional nozzles, the bubble and pintle coaxial nozzle of the present invention uses the sub-mold bubble nozzle as an ignition and flame stabilizer, and there is no need to set up a torch igniter or other high-energy device; compared with traditional pintle nozzles, the flow adjustment range is wider, and the required maximum flow adjustment can be achieved. At the same time, reliable ignition and stable combustion can be achieved when the minimum flow is greater than or equal to 25:1; compared with pintle nozzles, the combustion efficiency in low flow conditions such as overly rich fuel or oxygen-rich conditions is not less than 95%, while the combustion efficiency of traditional pintle nozzles is usually less than 80%.

[0024] The bubble and pintle coaxial injection design method of the present invention adopts a compact layout partition type four-cavity design, and the obtained bubble and pintle coaxial nozzle has a simple and reliable structure, is lightweight, and has engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a cross-sectional view of the bubble and pintle coaxial nozzle of the present invention;

[0026] Figure 2 It is a stereoscopic view of the bubble and pintle coaxial nozzle of the present invention.

[0027] In the figure, 1. auxiliary mold; 2. main mold; 3. fuel manifold I; 4. oxidant manifold I; 5. fuel manifold II; 6. oxidant manifold II; 7. radial sealing ring. DETAILED DESCRIPTION

[0028] The present invention will be described below in conjunction with the accompanying drawings and embodiments.

[0029] Example: Figure 1 , Figure 2 As shown, the design method for coaxial injection of the bubble and the pintle of this embodiment includes the following steps:

[0030] S10. Determine the technical solution;

[0031] The main and auxiliary double-module nozzles are adopted. The auxiliary module 1 uses a bubble nozzle, and the main module 2 uses a pin nozzle. The two are coaxially injected;

[0032] S20. Determine the technical functions of each module;

[0033] The flow rate of the auxiliary module 1 is less than that of the main module 2; the bubble nozzle of the auxiliary module 1 realizes small-flow ignition and reliable combustion through bubble injection, and the pin nozzle of the main module 2 organizes combustion under large flow rate through pin injection; the high-temperature gas generated by the combustion of the bubble-injected gas serves as the ignition and flame-stabilizing torch for the pin-injected gas;

[0034] S30. Determine the flow rate requirements of each module;

[0035] The flow rate of the auxiliary module 1 is 1 / 5 - 1 / 10 of the maximum total flow rate, and is used to realize the mixing, atomization, injection and combustion organization of liquid fuel and gas oxidant at a maximum flow rate ratio of 3:1; through numerical simulation calculation, it is found that if the mixing atomization is greater than 3%, the combustion efficiency of the auxiliary module 1 is higher than 96% within the working range;

[0036] The minimum flow rate of the main module 2 is 80% - 100% of the maximum flow rate of the auxiliary module 1, and the forms of ring slot and ring slot injection or ring slot and hole injection are adopted; through numerical simulation calculation, it is found that when the injection momentum ratio of liquid fuel and gas oxidant is 0.5 - 3.0:1, sufficient atomization is ensured; when the ratio d of the maximum working flow rate to the minimum working flow rate of the main module 2 is greater than or equal to 5:1, the combustion efficiency is higher than 95%;

[0037] It is also found through numerical simulation calculation that if the flow rate ratio of the maximum flow rate of the main module 2 to the minimum flow rate of the auxiliary module 1 is greater than or equal to 25:1, the overall combustion efficiency is still higher than 95%;

[0038] S40. Determine the processing method of the bubble and pin coaxial nozzle;

[0039] The bubble nozzle of the auxiliary module 1 and the pin nozzle of the main module 2 are respectively manufactured by 3D additive manufacturing method; the auxiliary module 1 and the main module 2 have the same central axis. The auxiliary module 1 is inserted into the main module 2 from top to bottom, and the two are hermetically connected through a radial sealing ring 7 and threaded connection to obtain a bubble and pin coaxial nozzle.

[0040] The bubble and pin coaxial nozzle of this embodiment includes an auxiliary module 1 and a main module 2 with the same central axis. The auxiliary module 1 is a bubble nozzle, the main module 2 is a pin nozzle, the pin nozzle is sleeved outside the bubble nozzle, and the outlet of the bubble nozzle is located in the inner cavity of the pin nozzle;

[0041] In the upper part of the bubble and pintle coaxial nozzle, the auxiliary mold 1 and the main mold 2 are divided in half in an alternating manner to form two layers of four cavities; the upper layer is the fuel manifold cavity Ⅰ3 and the oxidant manifold cavity Ⅰ4 of the bubble nozzle of the auxiliary mold 1, which respectively provide liquid fuel and gaseous oxidant for the bubble nozzle; the lower layer is the fuel manifold cavity Ⅱ5 and the oxidant manifold cavity Ⅱ6 of the pintle nozzle of the main mold 2, which respectively provide liquid fuel and gaseous oxidant for the pintle nozzle; the fuel manifold cavity Ⅰ3 and the oxidant manifold cavity Ⅱ6 are opposite to each other in the upper and lower parts, and are located on the left side of the bubble and pintle coaxial nozzle; the oxidant manifold cavity Ⅰ4 and the fuel manifold cavity Ⅱ5 are opposite to each other in the upper and lower parts, and are located on the right side of the bubble and pintle coaxial nozzle;

[0042] The top of the bubble and pintle coaxial nozzle is provided with inlet pipes which are respectively connected with the fuel manifold chamber Ⅰ3 and the oxidant manifold chamber Ⅰ4 and the fuel manifold chamber Ⅱ5 and the oxidant manifold chamber Ⅱ6.

[0043] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes. For those familiar with the art, all features disclosed in the present invention, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way without departing from the principles of the present invention. The present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A jet injection design method with coaxial bubbles and plungers, characterized in that The injection design method comprises the following steps: S10. Determine the technical solution; A main and auxiliary dual-die nozzle is used, the auxiliary die (1) uses a bubble nozzle, and the main die (2) uses a pintle nozzle, and the two are coaxially sprayed; S20. Determine the technical role of each module; The flow rate of the auxiliary mold (1) is smaller than the flow rate of the main mold (2); the bubble nozzle of the auxiliary mold (1) realizes small flow rate ignition and reliable combustion through bubble injection, and the pintle nozzle of the main mold (2) organizes combustion under large flow rate through pintle injection; the high-temperature combustion gas generated by the combustion of the bubble injection gas serves as the ignition and flame stabilization torch of the pintle injection gas; S30. Determine the flow requirements of each module; The flow rate of the sub-mode (1) is 1 / 5 to 1 / 10 of the maximum total flow rate, and is used to achieve mixed atomization, injection and combustion organization of liquid fuel and gas oxidant at a maximum flow rate ratio of 3:1; the mixed atomization is greater than 3%; The minimum flow rate of the main mold (2) is 80% to 100% of the maximum flow rate of the sub-mold (1), and annular gap and annular gap injection or annular gap and hole injection is adopted; the injection momentum ratio of the liquid fuel and the gas oxidant is (0.5 to 3.0):1; the ratio d of the maximum working flow rate to the minimum working flow rate of the main mold (2) is greater than or equal to 5:1; The flow ratio of the maximum flow of the main mold (2) to the minimum flow of the auxiliary mold (1) is greater than or equal to 25:1; S40. Determine the processing method of the bubble and pintle coaxial nozzle; The bubble nozzle of the sub-mold (1) and the pintle nozzle of the main mold (2) are respectively manufactured by a 3D additive printing method; the sub-mold (1) and the main mold (2) have the same central axis, the sub-mold (1) is inserted into the main mold (2) from top to bottom, and the two are sealed by a radial sealing ring (7) and a threaded connection to obtain a bubble and pintle coaxial nozzle.

2. A bubble and plunger coaxial nozzle, which is designed by the bubble and plunger coaxial injection design method described in claim 1, and is characterized in that, The bubble and pintle coaxial nozzle comprises a secondary mold (1) and a main mold (2) with the same central axis, the secondary mold (1) is the bubble nozzle, the main mold (2) is the pintle nozzle, the pintle nozzle is sleeved on the outside of the bubble nozzle, and the outlet of the bubble nozzle is located in the inner cavity of the pintle nozzle; In the upper part of the bubble and pintle coaxial nozzle, the auxiliary mold (1) and the main mold (2) are divided into two layers by staggered half partitions to form a total of four cavities; the upper layer is the fuel manifold cavity I (3) and the oxidant manifold cavity I (4) of the bubble nozzle of the auxiliary mold (1), which respectively provide liquid fuel and gaseous oxidant to the bubble nozzle; The lower layer is a fuel manifold II (5) and an oxidant manifold II (6) of the pintle nozzle of the main mold (2), which respectively provide liquid fuel and gaseous oxidant to the pintle nozzle; the fuel manifold I (3) and the oxidant manifold II (6) are vertically opposite to each other and are located on the left side of the bubble and the pintle coaxial nozzle; the oxidant manifold I (4) and the fuel manifold II (5) are vertically opposite to each other and are located on the right side of the bubble and the pintle coaxial nozzle; The top of the bubble and pintle coaxial nozzle is provided with inlet pipes respectively connected with the fuel manifold chamber I (3) and the oxidant manifold chamber I (4) and the fuel manifold chamber II (5) and the oxidant manifold chamber II (6).

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