Thermal protection structure of plasma engine

Abstract

The invention relates to a plasma engine thermal protection structure, belongs to the technical field of engine thermal protection, solves the technical problem of structural damage risk caused by thermal deformation of large plasma engine thermal protection, and comprises a thermal protection block, a thermal protection structure shell, a spring pressing sheet, a thermal insulation gasket A, a thermal insulation gasket B and a threaded connection fastener. The thermal protection blocks are located on the outer side of the circumference of the plasma engine and provided with an inner lap joint edge structure and an outer lap joint edge structure, the thermal protection blocks are in lap joint with one another, and the multiple thermal protection blocks form a cylinder and are arranged outside the plasma engine in a sleeving mode. And the thermal protection structure shell is sleeved outside the cylindrical thermal protection block. The thermal protection block is further provided with a groove used for containing a spring pressing piece, and the spring pressing piece is used for pressing the thermal protection block so that the thermal protection block can be attached to the thermal protection structure shell. And the heat insulation gasket A and the heat insulation gasket B are fixed through a threaded connection fastener. The thermal protection structure is used for the plasma engine with the axial or radial thermal deformation larger than 3 mm.

Description

Technical Field

[0001] This invention belongs to the field of engine thermal protection technology, and specifically relates to a thermal protection structure for a plasma engine. Background Technology

[0002] The working principle of a plasma engine is to vaporize and ionize a medium using thermal and electrical energy to form plasma with a certain density distribution. Then, the plasma is accelerated and ejected by electric and magnetic fields to generate thrust, thus achieving propulsion. After tens of milliseconds of startup, the operating temperature of such a plasma engine is greater than 3000K, and the engine structure will undergo significant thermal deformation. Heat-sensitive electrical components such as thermal batteries, cables, and sensors are often installed near the engine, so thermal protection design is required for the plasma engine. The functions of the thermal protection structure of the plasma engine are: (1) to reduce the heat loss of the engine caused by conduction and thermal radiation, and to ensure that the ambient temperature in the structural compartment where the engine is installed is effectively controlled (under normal circumstances, in order to ensure the reliable operation of heat-sensitive electrical components such as thermal batteries, cables, and sensors, the maximum compartment temperature during engine operation shall not exceed 80℃); (2) to adapt to the thermal deformation of the engine during operation, and to avoid the thermal stress generated by the engine casing due to temperature rise caused by structural limitations.

[0003] Common thermal protection structures for plasma engines employ a passive thermal protection principle, using pre-formed nano-aerogel shells or plates for encapsulation. This approach is effective for small plasma engines (axial or radial thermal deformation less than 1 mm), utilizing the flexibility and limited compressive deformation capacity of the nano-aerogel plates to compensate for thermal deformation of the engine structure. However, for medium to large plasma engines (axial or radial thermal deformation greater than 3 mm), relying on the compressive deformation of the nano-aerogel plates to adapt to the thermal deformation of the plasma engine will lead to deterioration of the engine casing's stress, potentially causing structural failure. If a thermal expansion gap is placed between the plasma engine casing and the nano-aerogel protective layer, the casing and thermal protection structure will not be in contact before the plasma engine operates. This necessitates a structurally reinforced support design for the thermal protection structure to ensure sufficient dynamic strength and stiffness, adding a significant structural mass to the system. Summary of the Invention

[0004] To overcome the shortcomings of thermal protection in large plasma engines, which pose a risk of structural damage due to thermal deformation, this invention proposes a thermal protection structure for plasma engines.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A thermal protection structure for a plasma engine, used in a plasma engine with an axial or radial thermal deformation greater than 3 mm, includes at least three thermal protection blocks, a thermal protection structure shell, a spring pressure plate, a thermal insulation gasket A, a thermal insulation gasket B, and threaded fasteners.

[0007] The thermal protection blocks are located on the outer circumference of the plasma engine and have inner and outer overlapping edge structures. Each thermal protection block overlaps with the others, and several thermal protection blocks form a cylindrical shape, which is fitted onto the outside of the plasma engine. The outer shell of the thermal protection structure is fitted onto the cylindrical thermal protection blocks. The thermal protection blocks also have grooves for placing spring pressure plates, which are used to press the thermal protection blocks together, ensuring a close fit between the thermal protection blocks and the outer shell of the thermal protection structure.

[0008] The thermal protection structure shell, the engine mid-section flange, and the plasma engine mounting bracket are fixedly connected by threaded fasteners. The thermal protection structure shell, installed on the engine mid-section flange and the plasma engine mounting bracket, is used to axially limit and fix the thermal protection block.

[0009] Thermal insulation gaskets A and B are installed between the engine mid-section flange and the plasma engine mounting bracket. Thermal insulation gaskets A and B are fixed by threaded fasteners to prevent the working heat of the plasma engine from being conducted to the plasma engine mounting bracket and the outer shell of the thermal protection structure.

[0010] The aforementioned plasma engine thermal protection structure retains an axial clearance for axial thermal deformation and a radial clearance for radial thermal deformation between the outer shell of the thermal protection structure and the thermal protection block.

[0011] The aforementioned plasma engine thermal protection structure includes four thermal protection blocks, which are evenly distributed along the outer circumference of the plasma engine.

[0012] In the aforementioned plasma engine thermal protection structure, the overlap width is greater than 1 / 2 times the thermal deformation of the outer perimeter of the thermal protection structure shell.

[0013] In the aforementioned plasma engine thermal protection structure, the spring pressure plate is made of heat-resistant spring steel, using heat-resistant spring steel plate and manufactured by sheet metal forming.

[0014] In the aforementioned plasma engine thermal protection structure, the spring pressure plate is provided with an elongated oval hole to reduce heat conduction from the thermal protection block to the outer shell of the thermal protection structure.

[0015] The aforementioned plasma engine thermal protection structure includes a thermal protection block that is a nano-aerogel preform structure.

[0016] The beneficial effects of this invention are:

[0017] A thermal protection structure for a plasma engine is disclosed, which is a nano-aerogel preform structure. The thermal protection block is divided into four circumferentially symmetrical blocks. Axial thermal deformation of the engine is compensated by a pre-existing axial gap between the thermal protection block and the plasma engine casing. A radial gap is maintained between the outer shell of the thermal protection structure and the thermal protection block to accommodate radial thermal deformation of the engine. Radial movement and relative sliding of the segmented thermal protection blocks are used to adapt to the radial thermal deformation of the engine, while also providing adaptive thermal deformation compensation for larger thermal deformations generated during engine operation.

[0018] A thermal protection structure for a plasma engine includes an inner and outer overlapping edge structure on both sides of the thermal protection block, each edge being half the thickness of the thermal protection block. The width of the overlapping edge is greater than half the thermal deformation of the outer perimeter of the engine casing. During the radial movement and relative sliding of the thermal protection block, the inner and outer overlapping edge structures ensure that the gap between the thermal protection blocks does not become continuous, thus guaranteeing the same thermal protection effect as an integral thermal protection layer of equal thickness.

[0019] A thermal protection structure for a plasma engine is disclosed. Before the plasma engine operates, a spring-loaded plate provides an initial preload to ensure that the thermal protection block is tightly fitted to the engine housing. The thermal protection structure housing axially limits and fixes the thermal protection block. During engine operation, the spring-loaded plate continuously provides a clamping force through deformation to ensure that the thermal protection structure housing fits the engine housing. At the same time, the thermal protection structure adapts to the radial thermal deformation of the engine through radial movement and relative sliding.

[0020] A plasma engine thermal protection structure includes a spring pressure plate whose working area is the outer side of the thermal protection block. Its operating temperature is typically below 150°C, and it can be manufactured using conventional heat-resistant spring steel sheets through sheet metal forming. Elongated holes are made on the surface of the spring pressure plate to reduce heat conduction from the thermal protection block to the outer shell of the thermal protection structure.

[0021] A thermal protection structure for a plasma engine includes a heat-insulating gasket installed between the engine's mid-section flange and the plasma engine mounting bracket to prevent heat from the plasma engine during operation from being conducted to the plasma engine mounting bracket and the outer shell of the thermal protection structure. Attached Figure Description

[0022] Figure 1 This is an exploded view of the thermal protection structure of the plasma engine according to an embodiment of the present invention;

[0023] Figure 2 This is a 1 / 4 sectional isometric view of the thermal protection structure of the plasma engine according to an embodiment of the present invention, wherein the outer shell 4 of the thermal protection structure is 1 / 2 sectionalized.

[0024] Figure 3This is a cross-sectional view of the thermal protection structure of the plasma engine in an embodiment of the present invention before the engine is in operation;

[0025] Figure 4 This is a cross-sectional view of the thermal protection structure of the plasma engine in the engine operating state according to an embodiment of the present invention. The structure undergoes thermal deformation, and the dashed line represents the state before operation.

[0026] Figure 5 This is an isometric view of the plasma engine thermal protection structure in the state before engine operation according to an embodiment of the present invention; the outer shell of the thermal protection structure is not shown.

[0027] Figure 6 This is an isometric view of the thermal protection structure of the plasma engine in the engine operating state according to an embodiment of the present invention. The structure undergoes thermal deformation, and the dashed arrows represent the trend of thermal deformation.

[0028] Figure 7 This is the main view of the spring pressure plate;

[0029] Figure 8 This is a top view of the spring pressure plate;

[0030] Figure 9 This is an isometric view of the spring pressure plate.

[0031] Reference numerals: 1. Plasma engine, 2. Thermal protection block, 3. Spring pressure plate, 4. Thermal protection structure shell, 5. Plasma engine mounting bracket, 6. Engine mid-section flange, 7. Thermal insulation gasket A, 8. Thermal insulation gasket B, 9. Threaded fastener. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] A thermal protection structure for a plasma engine, such as Figure 1 , Figure 2 As shown, a thermal protection block structure was designed according to the outer shell structure of the plasma engine 1. The thermal protection blocks are divided into four circumferentially symmetrical structures. The thermal protection blocks are pre-formed nano-aerogel structures. Each thermal protection block has inner and outer overlapping edges designed on both sides, with a thickness of 1 / 2 of the thermal protection block. The width of the overlapping edges is greater than 1 / 2 times the thermal deformation of the outer circumference of the engine shell. Spring pressure plates 3 are installed in the grooves of the thermal protection blocks, providing pre-clamping force for the installation of the thermal protection blocks. The outer shell 4 of the thermal protection structure is fitted over the thermal protection blocks 2 (4 blocks).

[0035] See the installation status before the plasma engine is operational. Figure 3 and Figure 5Four thermal protection blocks 2 are symmetrically distributed around their circumference and are tightly fitted to the engine housing under the clamping force of the spring pressure plate 3. An axial clearance is maintained between the thermal protection blocks and the engine housing to accommodate axial thermal deformation of the engine. Figure 3 , Figure 5 (t2). The thermal protection structure shell 4 is fitted over the thermal protection blocks 2 (4 blocks in total). The thermal protection structure shell 4, the engine mid-section flange 6, and the plasma engine mounting bracket 5 are installed using threaded fasteners 9. Thermal insulation gaskets A7 and B8 are installed between the engine mid-section flange and the plasma engine mounting bracket to prevent heat from the plasma engine from being conducted to the plasma engine mounting bracket 5 and the thermal protection structure shell 4 during operation. The thermal protection structure shell 4 limits and fixes the axial direction of the thermal protection blocks 2 through its installation. A radial clearance is maintained between the thermal protection structure shell 4 and the thermal protection blocks 2 to accommodate the radial thermal deformation of the engine. Figure 3 (t1, t3, and t4).

[0036] The installation status during plasma engine operation is shown in [reference]. Figure 4 and Figure 6 As the engine begins operation, the engine casing temperature rises rapidly, and the engine structure begins to undergo thermal deformation. The axial or radial thermal deformation of medium to large plasma engines exceeds 3mm. Axial thermal deformation is compensated for by the axial gap between the thermal protection blocks and the engine casing. After radial thermal deformation occurs, the thermal protection blocks, tightly fitted to the engine casing, move radially under the action of engine thermal expansion and spring clamping force. Gaps form between each of the four thermal protection blocks, and they gradually separate. The inner and outer overlapping structures of the thermal protection blocks ensure that the gaps between them do not become continuous. Through this radial movement, the thermal protection blocks adapt to the radial thermal deformation of the engine. Since plasma engines primarily operate in a high-vacuum environment, heat is transferred through conduction and radiation. Therefore, during engine operation, the thermal protection effect of the thermal protection blocks is completely consistent with that of an integral thermal protection layer of the same thickness.

[0037] The structure of the spring pressure plate is shown below. Figure 7 , Figure 8 , Figure 9 The working area of ​​the spring pressure plate is the outer side of the heat protection block, and its working temperature is usually below 150℃. It can be produced by sheet metal forming using conventional heat-resistant spring steel plates. The spring pressure plate is designed based on its initial preload and the range of clamping force during operation. Opening elongated holes on the surface of the spring pressure plate can reduce heat conduction from the heat protection block to the outer shell of the heat protection structure.

[0038] This invention is applied to the thermal protection structure of a plasma engine. It compensates for the axial thermal deformation of the plasma engine by reserving an axial gap and adopts a segmented structure to adapt to the radial thermal deformation of the plasma engine by relative sliding. It can adaptively compensate for the large thermal deformation generated by the plasma engine during operation, and ensure that it has the same thermal protection effect as an integral thermal protection layer of the same thickness. At the same time, this plasma engine thermal protection structure maintains close contact with the engine structure and has good structural dynamic strength and stiffness by relying on the engine structure.

[0039] This invention can be widely applied to the thermal protection structure design of similar plasma engines and liquid / solid engines with similar structures, and has broad application prospects.

Claims

1. A thermal protection structure for a plasma engine (1) with an axial or radial thermal deformation greater than 3 mm, characterized in that, The heat protection block (2), the heat protection structure shell (4), the spring pressing sheet (3), the heat insulation washer A (7), the heat insulation washer B (8), and the threaded connection fastener (9) are included. The heat protection block (2) is located on the outer side of the circumference of the plasma engine (1), and the inner and outer lap joint edge structures are arranged. Each heat protection block (2) is lapped with each other, and a plurality of heat protection blocks (2) form a cylindrical shape and are sleeved outside the plasma engine (1); the heat protection structure shell (4) is sleeved outside the cylindrical heat protection block (2); the heat protection block (2) is further provided with a groove for placing the spring pressing sheet (3), and the spring pressing sheet (3) is used for pressing the heat protection block (2) to make the heat protection block (2) adhere to the heat protection structure shell (4). The heat protection structure shell (4), the engine middle section flange (6), and the plasma engine mounting rack (5) are fixedly connected through the threaded connection fastener (9); the heat protection structure shell (4) mounted on the engine middle section flange (6) and the plasma engine mounting rack (5) is used for axially limiting and fixing the heat protection block (2).

2. The plasma engine thermal protection structure of claim 1, wherein, The heat insulation washer A (7) and the heat insulation washer B (8) are mounted between the engine middle section flange (6) and the plasma engine mounting rack (5), and the heat insulation washer A (7) and the heat insulation washer B (8) are fixed through the threaded connection fastener (9) and are used for blocking the conduction of the working heat of the plasma engine (1) to the plasma engine mounting rack (5) and the heat protection structure shell (4).

3. The plasma engine thermal protection structure of claim 1, wherein, An axial gap for axial thermal deformation and a radial gap for radial thermal deformation are reserved between the heat protection structure shell (4) and the heat protection block (2).

4. The plasma engine thermal protection structure of claim 1 or 2 or 3, wherein, The heat protection block (2) is arranged in four pieces, and the four heat protection blocks (2) are uniformly distributed along the outer side of the circumference of the plasma engine (1).

5. The plasma engine thermal protection structure of claim 1 or 2 or 3, wherein, The lap joint edge width is greater than 1 / 2 times the thermal deformation amount of the outer circumference of the heat protection structure shell (4).

6. The plasma engine thermal protection structure of claim 1 or 2 or 3, wherein, The spring pressing sheet (3) is made of heat-resistant spring steel, and is prepared by adopting sheet metal forming.

7. The plasma engine thermal protection structure of claim 1 or 2 or 3, wherein, The spring pressing sheet (3) is provided with an oblong hole for reducing the heat conduction of the heat protection block (2) to the heat protection structure shell (4).

8. The plasma engine thermal protection structure of claim 1 or 2 or 3, wherein, The heat protection block (2) is a nano aerogel preformed structure.

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