Manufacturing process of single-component thrust chamber
By using inert gas for welding protection in the single-component thrust chamber manufacturing process and avoiding the contact of a single gas component with the catalyst, the problem of degradation of catalyst performance is solved, high-quality welding and airtightness is achieved, and the performance improvement of the thrust chamber and large-scale application is promoted.
Patent Information
- Application Number
- CN202510393684.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-06-13
AI Technical Summary
In the existing single-component thrust chamber manufacturing process, single gas components such as argon and helium used in the welding process will damage the performance of the catalyst, resulting in a decrease in the thrust chamber.
Inert gas is used for welding protection, and inert gas is avoided from entering the thrust chamber cavity during the welding process. After welding is completed, cool and cool the surroundings of the welds immediately to reduce heat transfer and gas impact on the catalyst.
It effectively protects the performance of the catalyst, improves the welding quality and airtightness of the thrust chamber, ensures the design and use indicators of the thrust chamber, and promotes the large-scale promotion of the new single-unit thrust chamber.
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Figure CN120140066A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of thrust chamber manufacturing, and particularly relates to a manufacturing process for a monopropellant thrust chamber, which is applied to the manufacturing of thrust chambers for small-thrust liquid rocket engines. Such thrust chambers can withstand high-temperature and high-pressure gas at temperatures above 1000 °C and pressures below 3 MPa. Background Art
[0002] The new monopropellant thrust chamber is a thrust chamber suitable for hydroxylammonium nitrate propellant. This propellant is basically non-toxic to the human body compared with existing conventional propellants and belongs to a green and environmentally friendly propellant. It has a high combustion temperature and requires a porous ruthenium-based catalyst for use. This catalyst is easily affected by temperature, resulting in a reduction in its catalytic ability, thereby affecting the thrust performance of the entire thrust chamber. At the same time, the conventional welding process uses argon for welding protection and helium for airtightness detection after welding. This welding process greatly reduces the catalyst effect in the monopropellant thrust chamber.
[0003] Therefore, there is a need to provide a new manufacturing process for monopropellant thrust chambers to control the welding quality while ensuring that the catalyst performance is not affected. Summary of the Invention
[0004] In order to overcome the deficiencies in the prior art, the inventor of the present invention has conducted intensive research and provided a manufacturing process for a monopropellant thrust chamber, which ensures the welding quality while controlling the heat transfer to the catalyst during the production process and avoiding contact with single-component gases, ensuring the performance of the catalyst, thereby completing the present invention.
[0005] The technical solution provided by the present invention is as follows:
[0006] In a first aspect, a manufacturing process for a monopropellant thrust chamber includes:
[0007] Do not load the catalyst inside the decomposition chamber, first weld the thrust chamber head and the decomposition chamber, and use an inert gas for weld protection during the welding process;
[0008] Load the catalyst inside the decomposition chamber, weld one end of the decomposition chamber and the transition section. During the welding process, the inner cavity of the thrust chamber is not filled with inert gas, and immediately cool down the weld area around the decomposition chamber after welding;
[0009] Weld the nozzle and the other end of the transition section. During the welding process, the inner cavity of the thrust chamber is not filled with inert gas, and immediately cool down the weld area around the transition section after welding;
[0010] Perform airtightness detection on the thrust chamber using compressed air and conduct welding quality inspection.
[0011] According to the manufacturing process for a monopropellant thrust chamber provided by the present invention, it has the following beneficial effects:
[0012] (1) The present invention provides a manufacturing process for a single-component thrust chamber. By controlling the heat transfer to the catalyst during the production process and avoiding contact with a single-component gas, the performance of the catalyst is ensured, and the design and use indicators of the thrust chamber are achieved, so that the new single-component can be promoted on a large scale.
[0013] (2) The present invention provides a manufacturing process for a single-component thrust chamber, which uses a special tool to adjust the welding angle between the nozzle and the turning section, so that the bending structure of the thrust chamber can be realized, ensuring the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a schematic diagram of the matching installation of the thrust chamber and the special tooling of the present invention;
[0015] Figure 2 It is a structural schematic diagram of the special tooling of the present invention.
[0016] Description of Figure Numbers
[0017] 1-head; 2-decomposition chamber; 3-turning section; 4-nozzle; 5-semi-pressure ring I; 6-support rod; 7-semi-pressure ring II; 8-fastening screw; 9-catalyst; 10-gas distribution plate; 11-fastening bolt; 12-soft hose; 13-laser generator; 14-support seat; 15-flange; 16-top rod. DETAILED DESCRIPTION
[0018] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.
[0019] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
[0020] In view of the problem that the conventional welding process uses argon for welding protection and helium for airtightness testing after welding, which greatly affects the effect of the catalyst in the single-component thrust chamber, the inventors have found through extensive research that single gas components such as argon and helium have a weakening effect on the catalyst. This is not limited by any theory. The reason may be that the single gas component can enter the catalyst through the pores of the catalyst, destroying the distribution state of the metal elements on the catalyst and reducing the performance, and the catalyst cannot normally participate in the catalytic reaction of the propellant.
[0021] In order to solve the problem that the catalyst is easily affected by temperature and single-component gas, causing its catalytic ability to decrease, thereby affecting the thrust performance of the entire thrust chamber, the present invention provides a manufacturing process for a single-component thrust chamber, comprising the following steps:
[0022] Step 1: Without loading the catalyst inside the decomposition chamber, first perform laser welding on the thrust chamber head and the decomposition chamber. During the welding process, introduce inert gases such as argon for weld protection to prevent weld oxidation and reduce welding quality.
[0023] In this step, when performing laser welding on the thrust chamber head 1 and the decomposition chamber 2, the catalyst 9 is not loaded inside the decomposition chamber 2; install a gas distribution plate 10 on the small-end flange of the head 1. Inert gases such as argon enter the head 1 through the gas distribution plate 10 and reach the weld area to protect the weld area inside the cavity of the decomposition chamber 2 from oxidation. The laser generator 13 is in the same plane as the weld, maximizing the use of the energy generated by the laser generator 13 to ensure that at a relatively low power of the laser generator 13, the weld penetration can meet the requirements. The laser generator 13 is equipped with a blow-off pipeline for inert gases such as argon, which can blow away the metal vapor during the welding process and also protect the weld after welding from oxidation. Control the power of the laser generator 13 and the rotation speed of the parts to be welded to complete the welding. The protection of inert gases such as argon should be turned off after the weld temperature drops to avoid oxidation of the weld surface at high temperatures and reduce welding quality.
[0024] The installation position of the gas distribution plate 10 corresponds to the small-end flange of the thrust chamber head 1. There are through holes axially inside, and pipelines for introducing the inert gas source, such as a flexible rubber tube 12, pass through the through holes; the gas distribution plate 10 is connected to the small-end flange of the head 1 through fasteners such as fastening bolts 11 and rotates with the head 1 to ensure the smooth flow of inert gas to the weld position during the welding process.
[0025] Step 2: Load the catalyst inside the decomposition chamber, and weld one end of the decomposition chamber and the transition section. To prevent the catalyst from being affected by a single-component gas, no inert gases such as argon are introduced into the inner cavity of the thrust chamber during the welding process. Immediately after welding, use a silk cloth dipped in alcohol to cool down the area around the weld of the decomposition chamber to reduce the thermal influence on the catalyst.
[0026] In this step, after loading the catalyst 9 inside the decomposition chamber 2, complete the welding of the decomposition chamber 2 and the transition section 3. To prevent the catalyst 9 from being affected by a single-component gas such as argon, no inert gases such as argon are introduced into the inner cavity of the decomposition chamber 2 during the welding process. During the welding process, the laser generator 13 is in the same plane as the weld. Control the power of the laser generator 13 and the rotation speed of the parts to be welded to complete the welding. Immediately after welding, use a silk cloth dipped in alcohol to cool down the area around the weld of the decomposition chamber 2 to reduce the heat transfer influence on the catalyst 9.
[0027] Step 3: Adjust the welding angle of the thrust chamber, and weld the nozzle and the other end of the transition section by laser welding. No inert gases such as argon are introduced into the inner cavity of the thrust chamber during the welding process. Immediately after welding, use a silk cloth dipped in alcohol to cool down the area around the weld of the transition section, focusing on reducing the heat transfer to the main body of the thrust chamber and reducing the thermal influence on the catalyst.
[0028] In this step, during the welding process of the nozzle 4, a special tool is used to adjust the welding angle between the laser generator 13 and the axial direction of the nozzle 4. This angle is determined when the parts are designed to avoid interference between the laser generator 13 and the head 1 during the welding process. The power of the laser generator 13 and the rotation speed of the parts to be welded are controlled to weld the nozzle 4 and the turning section 3. During the welding process, the inner cavity of the nozzle 4 is not passed through inert gases such as argon. Immediately after the welding is completed, a silk cloth dipped in alcohol is used to cool the area around the weld of the turning section 3 to reduce the heat transfer effect on the catalyst 9.
[0029] The special tooling includes a support rod 6, a half pressure ring I 5, a half pressure ring II 7 and fasteners such as a fastening screw 8. The support rod 6 includes a support seat 14, a flange 15 and a push rod 16; the outer profile of the support seat 14 is the same as the inner profile of the nozzle 4, but the length is shorter, so that the nozzle 4 can be completely fitted with the support seat 14, and when the nozzle 4 is tightened, the nozzle will not be deformed by force, and the dimensional accuracy will not be affected. The half pressure ring I 5 and the half pressure ring II 7 are used in pairs, and the two are assembled into a complete pressure ring. The inner profile of the pressure ring is the same as the outer profile of the nozzle 4, and fits the outer side of the nozzle 4. The half pressure ring I 5 and the half pressure ring II 7 are installed on the flange 15 by fasteners such as fastening screws 8, and the gap between the half pressure ring I 5 and the half pressure ring II 7 and the support seat 14 is controlled by twisting the fasteners such as the fastening screws 8, so that the nozzle 4 is fixed on the support rod 6.
[0030] Step 4: Perform air tightness test on the thrust chamber to verify the air tightness of the thrust chamber. The gas component is compressed air, and single-component gas media such as helium cannot be used. Extract products from the front, middle and late stages of welding in this batch for planing to verify whether the welding penetration meets the requirements.
[0031] In this step, when the thrust chamber is tested for air tightness, a soft rubber pad is added between the support seat 14 and the nozzle 4, and after the half-pressure ring I 5 and the half-pressure ring II 7 are installed, the fastening screw 8 is installed to achieve sealing at the nozzle 4 outlet; the air distribution plate 10 is installed on the head 1, and after the compressed air with a pressure of 3.5-4.0MPa is introduced, the thrust chamber is placed in water, and the welds at various locations are observed to verify the air tightness of the thrust chamber.
[0032] Embodiment
[0033] A manufacturing process of a monopropellant thrust chamber comprises the following steps:
[0034] (1) Pickling treatment is carried out on each welded component such as the decomposition chamber 2, the turning section 3, and the nozzle 4 that are supporting a single-component thrust chamber. Control the pickling time to be 10 - 15 minutes and the acid solution temperature to be 22 °C. When laser welding the head 1 and the decomposition chamber 2, the catalyst 9 is not filled inside the decomposition chamber 2; install the air distribution disc 10 on the small-end flange of the head 1, and pass argon gas through the air distribution disc 10 to reach the weld position. The argon gas flow rate is 15 - 20 L / min. The laser generator 13 and the weld are in the same plane. The laser power is 600 - 800 W, and the rotation speed of the parts to be welded is 2 m / min to complete the welding; the protection of inert gases such as argon should be turned off after the weld temperature drops to avoid oxidation of the weld surface at high temperatures.
[0035] (2) After filling the catalyst 9 inside the decomposition chamber 2, carry out the welding of the decomposition chamber 2 and the turning section 3. During the welding process, no argon gas is passed through the inner cavity of the decomposition chamber 2. The laser generator 13 and the weld are in the same plane. The laser power is 800 W, and the rotation speed of the parts to be welded is 2 m / min. After the welding is completed, immediately use a silk cloth dipped in alcohol to cool down the area around the weld of the decomposition chamber 2 to reduce the heat transfer effect on the catalyst 9.
[0036] (3) During the welding process of the nozzle 4 and the turning section 3, use a special tooling to adjust the welding angle between the laser generator 13 and the axis of the nozzle 4 to avoid interference between the laser generator 13 and the head 1 during the welding process. Control the power of the laser generator 13 to be 1200 - 1500 W, and the rotation speed of the parts to be welded is 1.5 m / min. No argon gas is passed through the inner cavity of the nozzle 4 during the welding process. After the welding is completed, immediately use a silk cloth dipped in alcohol to cool down the area around the weld of the turning section 3.
[0037] (4) When performing airtight detection on the thrust chamber, add a soft rubber pad between the support seat 14 and the nozzle 4. After installing the semi-pressure ring I 5 and the semi-pressure ring II 7, install the fastening screw 8. Install the air distribution disc 10 on the head 1, pass compressed air with a pressure of 3.5 MPa, place the thrust chamber in water, observe each weld, and verify the airtightness of the thrust chamber;
[0038] (5) Take samples of this batch of welded products for planing. The quality of each weld meets the standard requirements; select this batch of thrust chambers for hot commissioning. Parameters such as the chamber pressure and start-up time of the thrust chamber meet the design indicators, thereby indicating that the manufacturing process of the present invention can solve the problem that the catalyst is easily affected by temperature and single-component gas and its performance is reduced, which in turn affects the thrust performance of the entire thrust chamber.
[0039] The present invention has been described in detail in conjunction with specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications or improvements can be made to the technical solutions of the present invention and their implementation manners, and all of these fall within the scope of the present invention. The protection scope of the present invention shall be subject to the appended claims.
[0040] The content not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.
Claims
1. A manufacturing process for a monopropellant thrust chamber, characterized in that: The steps include: No catalyst is loaded inside the decomposition chamber, and the thrust chamber head and the decomposition chamber are welded first, with inert gas used for weld protection during the welding process; The catalyst is loaded inside the decomposition chamber, and the decomposition chamber is welded to one end of the turning section. During the welding process, the inner cavity of the thrust chamber is not passed with inert gas. After the welding is completed, the area around the weld of the decomposition chamber is immediately cooled down; The nozzle is welded to the other end of the turning section. During the welding process, no inert gas is passed through the thrust chamber. After the welding is completed, the area around the welding seam of the turning section is cooled immediately. Compressed air is used to test the air tightness of the thrust chamber and to inspect the welding quality.
2. The manufacturing process of the monopropellant thrust chamber according to claim 1, characterized in that: When the thrust chamber head and the decomposition chamber are laser welded, no catalyst is loaded inside the decomposition chamber; a gas distribution plate is installed on the small end flange of the thrust chamber head, and inert gas enters the head through the gas distribution plate to reach the weld position; the laser generator is provided with an inert gas blowing pipeline to blow away metal vapor during the welding process and protect the weld after welding from being oxidized; the power of the laser generator and the rotation speed of the parts to be welded are controlled to complete the welding.
3. The manufacturing process of the monopropellant thrust chamber according to claim 2, characterized in that: The gas distribution plate corresponds to the installation position of the small end flange of the thrust chamber head, and has an axial through hole inside, through which a pipeline of an inert gas source is passed; the gas distribution plate and the small end flange of the head are connected by fasteners, and as the head rotates, the inert gas can flow smoothly to the weld position during welding.
4. The manufacturing process of the monopropellant thrust chamber according to claim 1, characterized in that: When the thrust chamber head and the decomposition chamber are laser welded, the laser generator and the weld are in the same plane.
5. The manufacturing process of the monopropellant thrust chamber according to claim 1, characterized in that: When the decomposition chamber is welded to one end of the turning section, the laser generator and the weld are in the same plane, and the power of the laser generator and the rotation speed of the parts to be welded are controlled to complete the welding; after the welding is completed, a fabric dipped in alcohol is immediately used to cool the area around the weld in the decomposition chamber.
6. The manufacturing process of the monopropellant thrust chamber according to claim 1, characterized in that: When the nozzle is welded to the other end of the turning section, a special tool is used to shape the nozzle, and the special tool includes a support rod, a half pressure ring I, a half pressure ring II and a fastener; the support rod includes a support seat, a flange and a push rod; the outer surface of the support seat has the same geometric shape as the inner surface of the nozzle, but is shorter in length, so that the nozzle is completely fitted with the support seat; the half pressure ring I and the half pressure ring II are used in pairs, and the two are assembled into a complete pressure ring, and the inner side surface of the pressure ring has the same geometric shape as the outer surface of the nozzle, and fits with the outer side of the nozzle; the half pressure ring I and the half pressure ring II are installed on the flange by fasteners, and the gap between the half pressure ring I and the half pressure ring II and the support seat is controlled by twisting the fasteners, so that the nozzle is fixed on the support rod.
7. The manufacturing process of the monopropellant thrust chamber according to claim 1, characterized in that: When the nozzle is welded to the other end of the turning section, the welding angle between the laser generator and the nozzle axis is adjusted so that the laser generator and the head do not interfere with each other during the welding process; the power of the laser generator and the rotation speed of the parts to be welded are controlled to complete the welding of the nozzle and the turning section; during the welding process, the inner cavity of the nozzle is not filled with inert gas, and after the welding is completed, a fabric dipped in alcohol is immediately used to cool the area around the weld of the turning section.
8. The manufacturing process of the monopropellant thrust chamber according to claim 6, characterized in that: When using compressed air to test the air tightness of the thrust chamber, add a soft rubber pad between the support seat and the nozzle. After installing the half-compression ring I and half-compression ring II, install the fasteners to seal the nozzle outlet. Install the air distribution plate on the head, and after introducing compressed air, put the thrust chamber into water, observe the welds at various locations, and verify the air tightness of the thrust chamber.
9. The manufacturing process of a monopropellant thrust chamber according to claim 1, characterized in that: During welding quality inspection, products from the early, middle and late stages of welding in this batch are sampled for planing to verify whether the welding penetration meets the requirements.