Regenerative cooling and heat insulation structure of high-temperature surface of aerospace engine and aerospace engine

Abstract

The present application relates to the technical field of air and space engine surface cooling, and discloses a regenerative cooling and heat insulation structure for the high-temperature surface of an air and space engine and the air and space engine, which comprises a fuel delivery device, a heat insulation and cooling channel, a movable support, a connecting channel and an engine body cooling channel; the heat insulation and cooling channel is outside the outer surface of the engine body cooling channel, and the heat insulation and cooling channel and the engine body cooling channel are connected by the movable support for spacing support, so that the heat insulation and cooling channel and the engine body cooling channel are arranged in a spaced manner; the fuel delivery device, the heat insulation and cooling channel, the connecting channel and the engine body cooling channel are sequentially connected and arranged; fuel is supplied and output by the fuel delivery device, the fuel first enters the heat insulation and cooling channel to form heat insulation for the high-temperature surface of the engine, then enters the engine body cooling channel through the connecting channel to cool the engine body structure, and finally is combusted in a high-temperature state to realize energy regeneration.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air and space engine surface cooling, in particular, to a regenerative cooling and heat insulation structure for high-temperature surface of an air and space engine and the air and space engine. BACKGROUND

[0002] When an air and space engine operates for a long time at a high speed, the internal gas and the surface temperature of the components are extremely high, and the thermal load is severe. In order to ensure the structural integrity of the engine, a regenerative cooling technology is usually used, that is, liquid fuel carried by the engine itself is used as a cooling medium, which flows in the pre-set cooling channel of the high-temperature component, absorbs heat through forced convection heat exchange, and actively cools the structure. The heated fuel enters the combustion chamber for combustion, thereby realizing energy recycling and improving the thermal efficiency of the engine.

[0003] However, the conventional regenerative cooling technology mainly focuses on controlling the temperature of the main body structure of the engine (such as the combustion chamber wall and the turbine) within the allowable range of the material (for example, for stainless steel material, the structure temperature usually needs to be controlled below 800 DEG C). Although this can ensure the structural strength, the temperature of the outer surface of the cooled engine is still high. If the high-temperature surface is directly exposed, it will transfer a large amount of heat to the surrounding cabin environment through thermal radiation and other forms, causing the cabin temperature to exceed the allowable working temperature of the electronic equipment, fuel pump, valve and other key components, and seriously affecting their reliability and service life.

[0004] In order to reduce the influence of the outer surface temperature of the engine on the cabin environment, a low thermal conductivity heat insulation material (such as aerogel) is usually coated on the high-temperature surface of the engine in the prior art. The heat insulation layer can passively reduce the radiation and convection heat transfer to the outside, thereby maintaining the cabin temperature within the acceptable range of the equipment. However, such passive heat insulation scheme has the following inherent defects:

[0005] Firstly, the passive heat insulation layer itself does not have the ability of active heat dissipation. As the working time of the engine is prolonged, the heat continues to accumulate in the heat insulation layer and the engine structure. In order to meet the cabin temperature control requirements, the thickness of the heat insulation layer often needs to be increased, which will directly lead to a significant increase in the weight of the engine system and the occupation of valuable cabin space.

[0006] Secondly, the preparation process of high-performance heat insulation materials (such as aerogel) is complex and the cost is high, which is not conducive to the low-cost and large-scale application of air and space engines.

[0007] Thirdly, after experiencing a high-temperature environment, the microstructure of such heat insulation materials is prone to irreversible change, resulting in degradation of the heat insulation performance, and it is difficult to maintain stable heat insulation effect in reusable air and space engines. SUMMARY

[0008] The application provides a regenerative cooling heat insulation structure of a space air engine high-temperature surface and the space air engine, which can balance effective heat insulation and active heat management, controls the engine outer surface temperature, avoids excessive increase of system weight and cost, and adapts to the reusable working requirements, so as to solve the technical problems that the existing passive heat insulation scheme cannot actively discharge heat, the system weight is large, the cost is high, and the engine is difficult to reuse during long-time working.

[0009] According to one aspect of the application, a regenerative cooling heat insulation structure of a space air engine high-temperature surface is provided, which comprises a fuel delivery device, a heat insulation cooling channel, a movable support, a connecting channel and an engine body cooling channel; the heat insulation cooling channel is outside the outer surface of the engine body cooling channel, the heat insulation cooling channel and the engine body cooling channel are connected and supported by the movable support, so that the heat insulation cooling channel and the engine body cooling channel are arranged in a spaced manner; the fuel delivery device, the heat insulation cooling channel, the connecting channel and the engine body cooling channel are sequentially connected and arranged; fuel is supplied and output through the fuel delivery device, the fuel first enters the heat insulation cooling channel to form heat insulation for the high-temperature surface of the engine, then enters the engine body cooling channel through the connecting channel to cool the engine body structure, and finally is combusted in a high-temperature state to realize energy regeneration.

[0010] Further, the surface where the heat insulation cooling channel is located and the surface where the engine body cooling channel is located are arranged in parallel.

[0011] Further, the surface where the heat insulation cooling channel is located and the surface where the engine body cooling channel is located are arranged in a gradually changing interval manner; or the surface where the heat insulation cooling channel is located and the surface where the engine body cooling channel is located are arranged in a suddenly changing interval manner.

[0012] Further, the structure design of the heat insulation cooling channel comprises: design target setting, the heat insulation cooling channel is used for insulating the high-temperature outer wall of the engine body cooling channel, that is, insulating the heat radiated and conducted by the high-temperature surface of the engine, the allowable temperature is lower than that of the engine body cooling channel, and the target is set to be not higher than 100 DEG C; considering heat insulation effectiveness, in the case of known high-temperature surface temperature, the heat flux transferred to the heat insulation cooling structure is calculated according to the heat radiation of the high-temperature surface, the air convection heat transfer and the heat conduction of the movable support; the size parameters of the heat insulation cooling channel are designed according to the Baz formula and the fuel flow under typical working conditions, and the design target is to ensure that the outer wall temperature of the heat insulation cooling channel is not higher than 100 DEG C.

[0013] Further, the material selection of the heat insulation cooling channel, under the premise of ensuring the strength of the bearing structure, light materials are used, and the thickness of the channel wall is reduced, so as to reduce the overall weight of the engine.

[0014] Further, the material of the heat-insulating cooling channel adopts a low-density and low-cost composite material, which includes an aluminum alloy or a titanium alloy.

[0015] Further, the connecting channel is integrally welded with the heat-insulating cooling channel and the engine body cooling channel, respectively, or the connecting channel is integrally printed with the heat-insulating cooling channel and the engine body cooling channel.

[0016] Further, the outlet of the heat-insulating cooling channel and / or the inlet of the engine body cooling channel is provided with a liquid accumulation cavity to realize fuel collection and distribution.

[0017] Further, the periphery of the connecting channel is further provided with a support structure for supporting between the heat-insulating cooling channel and the engine body cooling channel.

[0018] Further, the outlet of the heat-insulating cooling channel and / or the inlet of the engine body cooling channel is provided with a liquid accumulation cavity to realize fuel collection and distribution; the periphery of the connecting channel is further provided with a support structure for supporting between the heat-insulating cooling channel and the engine body cooling channel.

[0019] Further, the movable support includes a rolling support and a limiting seat, the rolling support is arranged on the outer wall surface of the heat-insulating cooling channel, the limiting seat is arranged on the outer wall surface of the engine body cooling channel, the rolling part of the rolling support is in rolling contact with the limiting groove of the limiting seat, so as to adapt to the deformation displacement caused by the temperature difference between the heat-insulating cooling channel and the engine body cooling channel and limit the circumferential rotation of the heat-insulating cooling channel.

[0020] Further, the movable support includes a sliding support and a sliding rail, the sliding support is arranged on the outer wall surface of the heat-insulating cooling channel, the sliding rail is arranged on the outer wall surface of the engine body cooling channel, the sliding block of the sliding support is slidably arranged on the sliding rail, so as to adapt to the deformation displacement caused by the temperature difference between the heat-insulating cooling channel and the engine body cooling channel and limit the circumferential rotation of the heat-insulating cooling channel.

[0021] According to another aspect of the present application, an aerospace engine is also provided, which includes the regenerative cooling and heat-insulating structure of the aerospace engine high-temperature surface.

[0022] The present application has the following beneficial effects:

[0023] 1. Achieved the leap from "passive insulation" to "active insulation", solved the problem of heat accumulation: change the fuel delivery path to flow through the outer side of the insulation cooling channel first, then through the connecting channel into the inner side of the engine body cooling channel, the normal temperature or low temperature fuel first flows through the high temperature surface outside as a cold source, actively absorbs and carries away the heat that would otherwise be radiated to the cabin, equivalent to setting an active and movable cold barrier between the high temperature surface and the external environment, achieving active thermal management, avoiding the vicious cycle of longer working time and thicker insulation requirement.

[0024] 2. Reduced system weight and volume, conducive to lightweight and compact design of the engine: due to the active heat dissipation capability of the insulation cooling channel, the engine outer surface temperature is effectively suppressed, greatly reducing the dependence on passive insulation materials, so the expensive and bulky aerogel passive insulation layer can be thinned or even removed, the insulation cooling channel itself as a structural part, its weight increase is far less than the weight of the thick insulation layer replaced, thus achieving the overall weight reduction and space saving of the system.

[0025] 3. Improved the reliability and adaptability of the structure, especially suitable for reusable scenarios: the design of the movable support allows relative displacement between the insulation cooling channel and the engine body cooling channel, effectively compensating for thermal stress caused by temperature changes, preventing structural damage due to thermal expansion and contraction, improving durability, and the entire insulation function is mainly achieved by the flow of fuel, which is newly supplied and recycled in each mission, so the insulation performance will not degrade with repeated use, overcoming the performance degradation of traditional insulation materials, providing support for the reuse of the engine.

[0026] 4. Achieved energy cascade utilization, optimized the thermal management efficiency of the whole system: forms an efficient energy utilization closed loop, the fuel is used as insulation medium (absorbs heat in the insulation cooling channel) and cooling medium (absorbs heat in the engine body cooling channel) in turn, and finally as fuel into the combustion chamber, this "insulation first, cooling second, combustion third" path realizes the cascade and full utilization of fuel heat absorption capacity, not only efficiently recovers waste heat at the system level, but also integrates the two independent thermal management problems of cabin thermal protection and engine structure cooling for collaborative solution, improving the thermodynamic integrity of the entire power system.

[0027] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The present application will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, illustrate the preferred embodiments of the application and assist in

[0029] Figure 1 is a structural schematic diagram of the regenerative cooling and heat insulation structure of the hypersonic engine high temperature surface of the preferred embodiment of the present application;

[0030] Figure 2 is a structural schematic diagram of the first connecting channel of the regenerative cooling and heat insulation structure of the hypersonic engine high temperature surface of the preferred embodiment of the present application;

[0031] Figure 3 is a structural schematic diagram of the second connecting channel of the regenerative cooling and heat insulation structure of the hypersonic engine high temperature surface of the preferred embodiment of the present application;

[0032] Figure 4 is a structural schematic diagram of the movable support of the regenerative cooling and heat insulation structure of the hypersonic engine high temperature surface of the preferred embodiment of the present application.

[0033] Legend:

[0034] 100, fuel delivery device; 200, heat insulation and cooling channel; 300, movable support; 400, connecting channel; 500, engine body cooling channel; 600, liquid accumulation cavity. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described in detail below with reference to the accompanying drawings, but the present application can be implemented in various different ways as defined and covered by the following.

[0036] As Figure 1The regeneration cooling and heat insulation structure of the high-temperature surface of the aerospace engine of the embodiment includes a fuel delivery device 100, a heat insulation cooling channel 200, a movable support 300, a connecting channel 400, and an engine body cooling channel 500; the heat insulation cooling channel 200 is outside the outer surface of the engine body cooling channel 500, the heat insulation cooling channel 200 and the engine body cooling channel 500 are connected and supported by the movable support 300, so that the heat insulation cooling channel 200 and the engine body cooling channel 500 are arranged in a spaced manner; the fuel delivery device 100, the heat insulation cooling channel 200, the connecting channel 400, and the engine body cooling channel 500 are sequentially connected and arranged; fuel is supplied and output through the fuel delivery device 100, the fuel first enters the heat insulation cooling channel 200 to form heat insulation for the high-temperature surface of the engine, then enters the engine body cooling channel 500 through the connecting channel 400 to cool the engine body structure, and finally is burned in a high-temperature state to realize energy regeneration. The regeneration cooling and heat insulation structure of the high-temperature surface of the aerospace engine changes the fuel delivery path to flow through the heat insulation cooling channel 200 outside first, and then enter the engine body cooling channel 500 inside through the connecting channel 400, the fuel at normal temperature or low temperature first flows through the outside of the high-temperature surface as a cold source, actively absorbs and carries away the heat that would be radiated to the cabin through convection heat exchange, which is equivalent to setting a movable cold barrier between the high-temperature surface and the external environment, realizing active heat management and avoiding the vicious cycle of longer working time and thicker heat insulation requirement. Since the heat insulation cooling channel 200 has the ability to actively dissipate heat, the temperature rise of the outer surface of the engine is effectively suppressed, the dependence on passive heat insulation materials is greatly reduced, and therefore the expensive and bulky aerogel passive heat insulation layer can be thinned or even cancelled, the heat insulation cooling channel 200 itself serves as a structural part, and the increase in weight is much smaller than the weight of the replaced thick heat insulation layer, thereby realizing the overall weight reduction and space saving of the system. The design of the movable support 300 allows the relative displacement between the heat insulation cooling channel 200 and the engine body cooling channel 500, effectively compensating for the thermal stress caused by the sharp change in temperature, preventing the structure from being damaged due to thermal expansion and contraction, and improving the durability. The entire heat insulation function is mainly realized by the flow of fuel, and the fuel is newly supplied and recycled in each task, so the heat insulation performance will not be degraded after multiple uses, overcoming the performance degradation of traditional heat insulation materials and providing support for the reuse of the engine.The regenerative cooling and heat insulation structure constitutes an efficient energy utilization closed loop, fuel is used as heat insulation medium (absorbing heat in the heat insulation cooling channel 200) and cooling medium (absorbing heat in the engine body cooling channel 500) in turn, and finally enters the combustion chamber as fuel. The path of "first heat insulation, then cooling, and then combustion" realizes the step-by-step and full utilization of the fuel heat absorption capacity, not only efficiently recovers waste heat at the system level, but also solves the two independent thermal management problems of cabin thermal protection and engine structure cooling in a collaborative manner, improving the thermodynamic integrity of the entire power system. The regenerative cooling and heat insulation structure of the high-temperature surface of the aerospace engine changes the flow sequence of the fuel, adds and preferentially uses the heat insulation cooling channel 200, expands the single regenerative cooling function to the dual function of "active heat insulation and main cooling", and ingeniously uses the cold energy of the fuel itself to intervene from the source of heat transfer, not only effectively controls the engine outer surface temperature and protects the equipment in the cabin, but also solves the core bottleneck problems of the traditional passive heat insulation scheme, such as large system weight, high cost, and difficulty in reuse, providing an efficient and reliable thermal protection solution for the development of long-duration, lightweight, and reusable aerospace engines. The fuel delivery device 100 includes a fuel pump.

[0037] As Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, in the present embodiment, the surface where the heat-insulating cooling channel 200 is arranged is parallel to the surface where the engine body cooling channel 500 is arranged. The surface where the heat-insulating cooling channel 200 is arranged is parallel to the surface where the engine body cooling channel 500 is arranged, and the heat-insulating cooling channel 200 maintains a substantially uniform distance from the high-temperature surface below that needs to be protected, i.e., the outer surface of the engine body cooling channel 500. When the fuel flows through the heat-insulating cooling channel 200, this equal-distance flow channel design can ensure uniform and stable convective heat exchange between the low-temperature fuel and the high-temperature surface, avoiding local cooling dead angles caused by channel distortion or uneven spacing, thereby effectively preventing local heat accumulation on the high-temperature surface and ensuring the uniformity and reliability of the heat-insulating effect, providing a stable low-temperature environment for the equipment in the cabin. Compared with a complex flow channel layout that is not parallel (e.g., intersecting or oblique), a parallel flow channel has the characteristics of smooth flow path and relatively small flow resistance, which is conducive to reducing the delivery load of the fuel pump and improving system efficiency. At the same time, the parallel and uniform flow channel cross-section makes the flow rate and flow state of the fuel easier to control and predict, facilitating more accurate balancing of heat exchange efficiency and flow pressure loss during the design stage, thereby optimizing the performance of the heat-insulating cooling subsystem as a whole. The parallel planar layout is a regular and simple geometric relationship, making the structural design, processing and manufacturing of the heat-insulating cooling channel 200 itself, as well as the connection and assembly with the engine body through the movable support 300, more convenient. The simplification of the structure helps to improve manufacturing precision, reduce production cost, and reduce the potential leakage or failure risk due to complex structure. This regular structure also complements the design of the movable support 300, making it easier to design and arrange support points that can effectively adapt to thermal deformation.

[0038] In this embodiment, the surfaces of the thermal barrier cooling channel 200 and the surfaces of the engine body cooling channel 500 are arranged with gradually changing spacing or with suddenly changing spacing. The heat flux density and temperature distribution of different regions of the engine are usually uneven. The design with gradually changing spacing (e.g., from wide to narrow) or suddenly changing spacing allows the local heat exchange capacity to be customized according to the actual heat load distribution of the underlying high-temperature surface. In regions with particularly high heat flux density, the fuel flow rate and local heat exchange efficiency can be increased by reducing the spacing, thereby strengthening the cooling and thermal barrier of the key area. Conversely, in regions with lower heat load, the spacing can be increased to reduce flow resistance. This design actively matches the cooling and thermal barrier capacity with the heat load distribution, avoids the performance waste or local protection deficiency caused by parallel arrangement, and improves the overall thermal management efficiency. When the engine shape is irregular or limited by the surrounding installation space, it may be difficult to achieve equal spacing parallel arrangement. The design with gradually changing spacing or suddenly changing spacing provides higher design flexibility and adaptability, better adapts to complex structural boundary conditions, and ensures that the thermal barrier cooling function can still be effectively implemented in the case of limited space. In addition, the sudden change in spacing (e.g., setting steps or chambers) can actively induce secondary flow such as vortex flow, which plays a role in disturbing the fluid and destroying the thermal boundary layer in specific areas where enhanced heat exchange is required. Designing the surfaces of the thermal barrier cooling channel 200 and the surfaces of the engine body cooling channel 500 with gradually changing spacing or suddenly changing spacing breaks through the limitations of uniform thermal management, realizes customizable and fine control of cooling and thermal barrier efficiency, and enables the cooling and thermal barrier capacity to actively adapt to the uneven heat flow distribution of the engine surface and complex structural constraints, thereby achieving optimal matching of thermal protection performance, flow resistance, and structural adaptability at the system level, providing an effective way to solve the problem of non-uniform thermal protection of high-temperature surfaces.

[0039] In this embodiment, the structure design of the heat insulation cooling channel 200 includes: setting the design target, the heat insulation cooling channel 200 is used to insulate the high-temperature outer wall of the engine body cooling channel 500, that is, to insulate the heat radiated and conducted by the high-temperature surface of the engine, the allowable temperature is lower than that of the engine body cooling channel 500, and the target is set to not exceed 100 DEG C; considering the heat insulation effect, in the case of known high-temperature surface temperature, the heat flux transferred to the heat insulation cooling structure is calculated according to the high-temperature surface radiation heat transfer, air convection heat transfer and heat conduction of the movable support 300; according to the Baz formula, and the fuel flow under the typical working condition, the size parameters of the heat insulation cooling channel 200 are designed, and the design target is to ensure that the outer wall temperature of the heat insulation cooling channel 200 is not higher than 100 DEG C. The design target of controlling the outer wall temperature of the heat insulation cooling channel 200 to not exceed 100 DEG C is set, the outer wall temperature of the heat insulation cooling channel 200 is controlled to not exceed 100 DEG C, and this target is directly related to the allowable working temperature of the equipment in the cabin, so that the design process has a purpose; by comprehensively considering the radiation, convection, conduction and other heat transfer modes to calculate the heat flux, and applying mature engineering formulas such as the Baz formula, the prediction of the heat insulation effect is improved from experience estimation to quantitative calculation level, and the heat insulation performance of the final product can be scientifically predicted in the design stage, which can reliably ensure that the cabin temperature is maintained within a safe range, and the reliability and success rate of the design are greatly improved. The size parameters (such as equivalent diameter, length, etc.) of the channel and the key working conditions (such as fuel flow, high-temperature wall temperature) are mathematically related through the heat transfer formula (Baz formula), so that the design process is no longer trial and error or overly conservative, but is based on a physical model to optimize parameters; through calculation, the channel size determined can seek the best balance point of flow resistance, weight and size under the premise of meeting the hard index of 100 DEG C outer wall temperature, so as to avoid the channel size being too large and the weight being too heavy due to design conservatism, or the heat insulation failure due to insufficient design, and realize the unity of lightweight and high performance. The design input (target temperature, heat flux), design tool (Baz formula) and design output (size parameter) are clear, and a complete technical path from the problem to the solution is outlined, which is predictable and reproducible.

[0040] In this embodiment, the target of the structure design of the heat insulation cooling channel 200 is set to be no more than 100℃, specifically: the final purpose of the design is not to cool the structure itself, but to ensure that the key components in the cabin, such as electrical equipment, fuel pumps, valves, etc. can work reliably below their allowable temperature. The maximum allowable temperature of these devices (for example, the upper limit of some components is 70℃ or 85℃) is a hard constraint condition for system design. Set the system boundary and establish the upper limit of the temperature of the outer wall of the heat insulation cooling channel. Inside the cabin, heat is transferred from the high-temperature structure of the engine to the equipment in the cabin, mainly through thermal radiation and convection. In order to fundamentally ensure the safety of the equipment, the most direct and effective method is to control the surface temperature of the heat source, that is, to control the outer wall temperature of the heat insulation cooling channel below a safe value lower than the minimum allowable temperature of all equipment; 100℃ is an integer threshold widely used in engineering with a significant safety margin, which is much lower than the allowable temperature of most equipment, leaving sufficient safety boundary for air convection and radiation heat transfer in the cabin, thereby ensuring that even under some operating condition fluctuations, the local maximum temperature in the cabin will never exceed the standard. The setting logic of the target of 100℃ is based on the layer-by-layer decomposition and transformation of the safety requirements of the final protected object (the equipment in the cabin). A vague effective heat insulation requirement is transformed into a precise, measurable, and executable engineering design instruction, ensuring the scientificity and reliability of the entire thermal protection system design.

[0041] In this embodiment, the material of the heat-insulating cooling channel 200 is selected to ensure the strength of the bearing structure, use lightweight materials, and reduce the thickness of the channel wall to reduce the overall weight of the engine. The heat-insulating cooling channel 200 itself also brings additional structural weight. By purposefully selecting lightweight materials with high specific strength (strength-to-density ratio) such as high-temperature aluminum alloys, titanium alloys, or composite materials, and based on the mechanical properties of the materials, the channel wall thickness is reduced as much as possible under the premise of ensuring pressure strength and stiffness, the weight of the new component can be minimized, which directly offsets the weight increase caused by the addition of the structure, even achieving net weight reduction, thereby significantly improving the power-to-weight ratio of the aerospace engine, positively affecting the maneuverability, flight time, and payload capacity of the aircraft. As the heat transfer interface between the fuel and the high-temperature outer wall, the physical properties of the heat-insulating cooling channel 200 will affect the heat transfer efficiency. Using lightweight materials (usually with good thermal conductivity) and reducing the wall thickness can effectively reduce the thermal resistance of the channel wall, allowing the fuel to absorb heat more efficiently and improving the effectiveness of active heat insulation. Thin-walled structures have lower thermal inertia, allowing them to reach thermal stability faster during engine startup and changes in operating conditions, improving the response speed of the thermal management system. This material selection principle reflects the design philosophy of changing from passive addition to active bearing. The heat-insulating cooling channel 200 is designed as a primary or secondary load-bearing structural component that must bear internal pressure, vibration, thermal stress, and other loads. By optimizing lightweight materials with high specific strength and thin-walled design, the fluid channel function and structural bearing function are highly integrated, avoiding the need for additional heavy brackets on the main engine structure, further optimizing the compactness and reliability of the system.

[0042] In this embodiment, the material of the heat-insulating cooling channel 200 adopts a low-density and low-cost composite material, which includes aluminum alloy or titanium alloy, etc. The use of the low-density and low-cost composite material for the material of the heat-insulating cooling channel 200 provides a feasible and superior performance material path for engineering implementation. Aluminum alloy can maximize the lightweight goal of the heat-insulating cooling channel 200 due to its extremely low density and excellent specific strength, and aluminum alloy has mature forming processes (such as extrusion, brazing) and connection technologies, so that the cost is controllable and the efficiency is high when manufacturing a complex flow channel structure. Titanium alloy has higher specific strength and excellent corrosion resistance and high-temperature resistance on the basis of maintaining a relatively low density, and is suitable for more demanding working conditions in terms of working environment temperature and structural strength. By using aluminum alloy or titanium alloy, which has been scaled up in the aerospace field, has a mature supply chain, and has a relatively controllable cost, to replace or reduce the dependence on expensive special materials, in addition, these metal materials have good fatigue resistance and damage tolerance, and their mechanical properties have less attenuation after multiple thermal cycles, which provides a guarantee for the structural integrity and functional stability of the heat-insulating cooling channel 200 in the reusable engine. Aluminum alloy and titanium alloy have good thermal conductivity, which ensures efficient heat transfer of the fuel flowing from the channel wall to the inside, reduces the temperature difference and thermal stress of the wall itself, and makes the active heat insulation effect more rapid and uniform. Combining the high thermal conductivity of the material with the thin-walled design of the structure further optimizes the overall thermal management efficiency.

[0043] As Figure 2As shown, in the embodiment, the connecting channel 400 is integrally welded with the heat-insulating cooling channel 200 and the engine body cooling channel 500, respectively. The connecting channel 400 is the only path for the fuel to flow from the heat-insulating cooling channel 200 to the engine body cooling channel 500, and the connection quality is directly related to the sealing integrity of the entire regenerative cooling system; the integrally welded connection means that the connection interface is a continuous, metallurgical bonding sealing structure, compared with the traditional detachable connection mode such as flange and thread, completely eliminating the leakage points that may occur at the joint, benefiting the aero-engine fuel system that bears high temperature, pressure fluctuation and vibration, ensuring that the cooling medium (fuel) completes the predetermined cooling cycle without leakage, thereby guaranteeing the reliability of the engine thermal protection system. The engine working environment is full of high-frequency vibration, and the detachable joint or local spot welding is easy to loosen or fatigue crack under vibration load; while the present application adopts the rigid integrated structure formed by integrally welding, which firmly combines the connecting channel 400 with the cooling channels (heat-insulating cooling channel 200 and engine body cooling channel 500) at both ends into one whole, improves the stiffness and strength of the connecting part, makes it able to effectively resist vibration and thermal stress alternating load, greatly reduces the risk of structural failure due to fatigue damage, greatly improves the long-term durability of the entire cooling and heat-insulating structure under harsh working conditions. Integrally welding can realize smooth transition of the flow passage at the connection, avoid the sudden change of flow cross section caused by flange, joint and other structures, effectively reduce unnecessary local eddy current and flow separation, thereby reducing the local pressure loss when the fluid passes through the connecting part, helping to optimize the fluid dynamics performance of the entire cooling flow passage, and having positive significance for reducing the power consumption demand of the fuel pump.

[0044] As Figure 3As shown, in this embodiment, the connecting channel 400 is integrated printed with the thermal insulation cooling channel 200 and the engine body cooling channel 500. Compared with traditional welding, integrated printing (i.e. using additive manufacturing technology such as 3D printing) further advances the manufacturing process to the material accumulation stage, directly manufacturing a whole continuous member that integrates the connecting channel 400, the thermal insulation cooling channel 200 and the engine body cooling channel 500, completely eliminating the traditional connecting interface, physically eliminating the possibility of leakage or rupture caused by welding defects, heat-affected zone performance degradation or poor sealing, and achieving the highest level of structural integrity and sealing reliability. Traditional machining or welding processes severely restrict the shape of the internal flow channel, and usually only simple straight holes or two-dimensional curved pipes can be achieved, while integrated printing technology is almost not limited by the geometric shape, allowing designers to break through the constraints of traditional processes and build three-dimensional complex flow channels with the best streamline, the smallest flow resistance and the highest heat exchange efficiency; for example, the connecting channel 400 can be designed in the shape of a Venturi tube to optimize flow or achieve the smoothest fluid transition from the annular thermal insulation channel to the internal serpentine cooling channel, which cannot be achieved by traditional methods, thereby optimizing the fluid and heat exchange performance of the system from the source. Integrated printing simplifies the once-forming printing process from the originally long process of manufacturing multiple parts (thermal insulation cooling channel 200, connecting channel 400, engine body cooling channel 500) and then complex assembly and welding, significantly reducing the number of parts, tooling fixtures and assembly processes, not only reducing manufacturing costs and cycle, but also further achieving overall weight reduction due to the reduction of additional structures such as flanges and gaskets designed for connection; at the same time, this technology is particularly suitable for manufacturing members with internal complex cooling channels, and is the most direct and efficient process path to achieve the complex structure described in the present application.

[0045] As Figure 3As shown, in the embodiment, the outlet of the insulation cooling channel 200 and / or the inlet of the engine body cooling channel 500 is provided with a liquid accumulation cavity 600 to realize the collection and distribution of fuel; and / or the periphery of the connecting channel 400 is further provided with a support structure for supporting between the insulation cooling channel 200 and the engine body cooling channel 500. The insulation cooling channel 200 and the engine body cooling channel 500 are composed of a plurality of parallel flow channels, and the liquid accumulation cavity 600 is arranged at the outlet of the insulation cooling channel 200 and / or the inlet of the engine body cooling channel 500, which can collect, buffer and redistribute the fuel from the upstream, so as to ensure that the fuel can uniformly flow into each parallel flow channel downstream, avoid the phenomenon that some flow channels have excessive flow and some flow channels have insufficient flow or even steam resistance due to uneven distribution, and thus ensure that each region of the high-temperature surface of the engine can obtain uniform and consistent cooling and insulation effect, and prevent local overheating. The volume space of the liquid accumulation cavity 600 can play a role in buffering and stabilizing pressure, can absorb the slight pressure pulsation caused by the fuel pump oil supply or the combustion chamber pressure feedback, and can make the flow into each cooling channel more stable, and improve the stability and reliability of the whole thermal management system. Although the movable support 300 is provided for support, when bearing the internal fuel pressure, external aerodynamic load and engine vibration, the area between the insulation cooling channel 200 and the engine body cooling channel 500 with a large area may still have relative deformation or vibration; the application adds a special support structure to the periphery of the connecting channel 400, which can provide additional, local constraint and support points, effectively suppress the bending deformation and harmful vibration of the plate-shaped structure, improve the stiffness and natural frequency of the whole composite cooling structure, and thus ensure the integrity and long-term service life of the structure under complex working conditions; the connecting channel 400 itself is a fluid channel, and its structural strength is limited, and the additional support structure can directly transmit part of the mechanical load acting on the insulation cooling channel 200 to the solid engine body, avoid the connecting channel 400 bearing excessive bending or shear stress, and play a role in protecting the key fluid channel from mechanical damage.

[0046] As Figure 1 and Figure 4As shown, in the embodiment, the movable support 300 comprises a rolling support and a limiting seat, the rolling support is arranged on the outer wall surface of the heat insulation cooling channel 200, the limiting seat is arranged on the outer wall surface of the engine body cooling channel 500, the rolling part of the rolling support is in rolling contact with the limiting groove of the limiting seat, so as to adapt to the deformation displacement caused by the temperature difference between the heat insulation cooling channel 200 and the engine body cooling channel 500 and limit the circumferential rotation of the heat insulation cooling channel 200; or the movable support 300 comprises a sliding support and a sliding rail, the sliding support is arranged on the outer wall surface of the heat insulation cooling channel 200, the sliding rail is arranged on the outer wall surface of the engine body cooling channel 500, and the sliding block of the sliding support is slidably arranged on the sliding rail, so as to adapt to the deformation displacement caused by the temperature difference between the heat insulation cooling channel 200 and the engine body cooling channel 500 and limit the circumferential rotation of the heat insulation cooling channel 200. When the engine works, the inner engine body cooling channel 500 directly bears high temperature, and the outer heat insulation cooling channel 200 has low-temperature fuel flowing through, and there is a huge temperature difference between the two, which will inevitably produce different degrees of thermal expansion. If the two are rigidly connected, the huge thermal stress will cause the structure to warp, the connection to crack and even be damaged; and the movable support 300 of the present application allows the heat insulation cooling channel 200 to have free or limited displacement relative to the engine body cooling channel 500 in the plane through the rolling pair or the sliding pair, thereby completely releasing the thermal stress caused by the temperature difference, and ensuring that the space double-layer structure can work long-term and safely under the thermal cycle working condition. Because uncontrolled circumferential rotation or misplacement will cause the connecting channel 400 to be twisted off or leaked, damage the sealing of the entire cooling flow path, and even cause the system to collapse; and the rolling pair or the sliding pair used in the present application both adapt to the deformation displacement and limit the circumferential rotation, allowing movement in a specific direction (such as axial or radial) to adapt to thermal expansion, while strictly limiting circumferential rotation. This precise constraint design ensures that the relative positional relationship of all functional components (especially the connecting channel 400) remains correct during thermal deformation, and the functional integrity of the cooling flow path is maintained. By using mechanical standard parts or design of rolling supports, limiting grooves, sliding blocks and sliding rails, the thermal deformation mode is changed from uncertain and random deformation to predictable and regular movement along the predetermined trajectory and direction. This predictability enables designers to accurately calculate the deformation amount and leave sufficient safety margin for components such as the connecting channel 400, thereby greatly improving the reliability and design success rate of the entire system.

[0047] The space engine of the embodiment comprises the regenerative cooling and heat insulation structure of the space engine high-temperature surface.

[0048] In implementation, for the space engine high-temperature surface, a regenerative cooling and heat insulation structure is provided, which specifically comprises: a heat insulation cooling channel structure arranged above the engine high-temperature surface, fuel supplied by a fuel pump first enters the heat insulation cooling channel 200 to form heat insulation for the engine high-temperature surface, and then enters the engine body cooling channel 500 through the connecting channel 400 to cool the engine body structure. The inner wall of the heat insulation cooling channel 200 is not in direct contact with the engine surface, but is connected through a movable support 300 capable of deforming. The normal-temperature fuel supplied by the fuel pump first enters the heat insulation cooling channel 200, and then enters the engine body cooling channel 500, so as to realize the heat insulation effect of the high-temperature surface by using the low oil temperature of the normal-temperature fuel.

[0049] Implementation process:

[0050] The regenerative cooling and heat insulation structure mainly comprises three parts: the heat insulation cooling channel 200, the connecting channel 400 and the movable support 300.

[0051] 1. Heat insulation cooling channel 200

[0052] The heat insulation cooling channel 200 is mainly used to insulate the high-temperature outer wall of the engine body cooling channel 500, i.e. the heat radiated and conducted by the engine high-temperature surface. Since the allowable temperature of the equipment is relatively low, which is mostly not more than 100℃, the normal-temperature oil supplied by the fuel pump should first pass through the heat insulation cooling channel 200. For the structural design of the heat insulation cooling channel 200, firstly, the heat insulation effect should be considered. In the case of known high-temperature surface temperature, the heat flux transferred to the heat insulation cooling structure is calculated according to the heat radiation and convection of the high-temperature surface and the heat conduction of the movable support 300. Then, the size parameters of the heat insulation cooling channel 200 are designed according to the classic heat transfer formula (Baz formula) and the fuel flow under typical working conditions. The design goal is to ensure that the outer wall temperature of the heat insulation cooling channel 200 is not higher than 100℃.

[0053] For the selection of the material for processing the heat insulation cooling channel 200, under the premise of ensuring the strength of the bearing structure, lightweight materials are used, and the thickness of the channel wall is reduced to reduce the overall weight of the engine. The materials that can be selected include aluminum alloy, titanium alloy, low-density and low-cost composite materials, etc.

[0054] 2. Connecting channel 400

[0055] The connecting channel 400 is mainly used to connect the outlet of the heat insulation cooling channel 200 and the inlet of the engine body cooling channel 500, so that the fuel that has completed the cooling function in the heat insulation cooling channel 200 enters the engine body cooling channel 500. This channel can be designed as Figure 2The structure shown is integrally connected to the heat insulation cooling channel 200 and the engine body cooling channel 500. This connecting channel 400 structure requires integral welding or integrated printing with the heat insulation cooling channel 200 and the engine body cooling channel 500. Its advantage lies in its good load-bearing capacity, ensuring sufficient space between the heat insulation cooling channel 200 and the engine body cooling channel 500 near the connection point to reduce heat transfer between the high-temperature engine body surface and the heat insulation channel. The connecting channel 400 can also be designed as an independent pipe connection structure, such as... Figure 3 As shown, this structure requires the outlet of the heat insulation cooling channel 200 and the inlet of the engine body cooling channel 500 to have a liquid collection chamber 600 to realize the collection and distribution of fuel. Its advantage is that the connecting channel 400 can be independently processed and connected to the liquid collection chamber 600 of the cooling channels on both sides (heat insulation cooling channel 200 and engine body cooling channel 500), and the assembly is more flexible. However, considering that the load-bearing capacity of the pipeline may be insufficient, additional support structures need to be added nearby.

[0056] 3. Activity support 300

[0057] The movable support 300 is mainly used to support the heat-insulating cooling channel 200 above the engine block cooling channel 500, and to ensure sufficient clearance between the two channels, such as... Figure 4 As shown. The support at one end of the heat-insulating cooling channel 200 can employ a sliding or rolling structure to ensure that when the temperature difference between the heat-insulating cooling channel 200 and the engine block cooling channel 500 is large, the support can match the axial deformation displacement. Simultaneously, a limiter or track needs to be installed on one side of the engine block cooling channel 500 to restrict the circumferential displacement of the heat-insulating cooling channel 200, thereby preventing rotation of the heat-insulating cooling channel 200 and resulting structural damage. The number and distribution of supports need to be determined based on the weight and deformation of the heat-insulating cooling channel 200 to ensure uniform stress distribution in the structure.

[0058] The beneficial effects of the regenerative cooling and heat insulation structure of this invention:

[0059] Compared to traditional passive heat insulation layers, the regenerative cooling insulation structure of this invention effectively avoids heat accumulation effects. Even under extremely long operating conditions, it maintains its insulation performance and weight. Furthermore, it allows the use of relatively inexpensive, lightweight materials to construct the cooling channels, achieving structural weight reduction and cost reduction. Simultaneously, the insulated cooling channel 200 can be designed and manufactured synchronously with the engine's main cooling channel 500, resulting in a higher degree of engine integration and significantly improving structural reliability and service life.

[0060] Matters not covered in this invention are common knowledge.

[0061] Any technical features in the above embodiments can be combined, and for brevity, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not contradict each other, they shall be considered within the scope of the present disclosure.

[0062] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it shall not be understood as a limitation on the scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these shall be within the protection scope of the present application.

[0063] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A regenerative cooling and heat insulation structure for the high-temperature surface of an aerospace engine, characterized in that, It includes a fuel delivery device (100), a heat-insulated cooling passage (200), a movable support (300), a connecting passage (400), and an engine body cooling passage (500). The heat-insulating cooling channel (200) is located on the outer side of the outer surface of the engine body cooling channel (500). The heat-insulating cooling channel (200) and the engine body cooling channel (500) are connected by a movable support (300) at intervals so that the heat-insulating cooling channel (200) and the engine body cooling channel (500) are arranged at intervals. The fuel delivery device (100), the heat insulation cooling passage (200), the connecting passage (400), and the engine body cooling passage (500) are sequentially connected and arranged; Fuel is supplied and output through a fuel delivery device (100). The fuel first enters the heat insulation cooling channel (200) to form heat insulation on the high-temperature surface of the engine, and then enters the engine body cooling channel (500) through the connecting channel (400) to cool the engine body structure. Finally, it is burned at a high temperature to achieve energy regeneration. The movable support (300) includes a rolling support and a limiting seat. The rolling support is arranged on the outer wall of the heat insulation cooling channel (200), and the limiting seat is arranged on the outer wall of the engine body cooling channel (500). The rolling part of the rolling support rolls into contact with the limiting groove of the limiting seat to accommodate the deformation displacement caused by the temperature difference between the heat insulation cooling channel (200) and the engine body cooling channel (500) and to limit the circumferential rotation of the heat insulation cooling channel (200).

2. The regenerative cooling and heat insulation structure for the high-temperature surface of an aerospace engine according to claim 1, characterized in that, The surface of the heat-insulating cooling channel (200) is arranged parallel to the surface of the engine body cooling channel (500).

3. The regenerative cooling and heat insulation structure for the high-temperature surface of an aerospace engine according to claim 1, characterized in that, The surface where the heat insulation cooling channel (200) is located is arranged with a gradually changing spacing from the surface where the engine body cooling channel (500) is located, or the surface where the heat insulation cooling channel (200) is located is arranged with a sudden change in spacing from the surface where the engine body cooling channel (500) is located.

4. The regenerative cooling and heat insulation structure for the high-temperature surface of an aerospace engine according to claim 1, characterized in that, The structural design of the heat-insulated cooling channel (200) includes: The design goal is to insulate the high-temperature outer wall of the engine body cooling channel (500) from the heat radiated and conducted by the high-temperature surface of the engine. The allowable temperature is lower than that of the engine body cooling channel (500), and the target is set to not exceed 100°C. Considering the effectiveness of thermal insulation, given the known high-temperature surface temperature, the heat flux transferred to the thermal insulation and cooling structure is calculated based on the high-temperature surface radiation heat transfer, air convection heat transfer, and the heat conduction of the movable support (300). Based on the BAZ formula and the fuel flow rate under typical operating conditions, the size parameters of the heat insulation cooling channel (200) are designed. The design goal is to ensure that the outer wall temperature of the heat insulation cooling channel (200) does not exceed 100℃.

5. The regenerative cooling and heat insulation structure for the high-temperature surface of an aerospace engine according to claim 4, characterized in that, The material selection for the heat-insulated cooling channel (200) takes into account the premise of ensuring the strength of the load-bearing structure, using lightweight materials and reducing the thickness of the channel wall.

6. The regenerative cooling and heat insulation structure for the high-temperature surface of an aerospace engine according to claim 5, characterized in that, The material of the heat-insulated cooling channel (200) is a low-density, low-cost composite material, including aluminum alloy or titanium alloy.

7. The regenerative cooling and heat insulation structure for the high-temperature surface of an aerospace engine according to any one of claims 1 to 6, characterized in that, The connecting channel (400) is welded to the heat insulation cooling channel (200) and the engine body cooling channel (500) as a whole piece, or the connecting channel (400) is integrated and printed with the heat insulation cooling channel (200) and the engine body cooling channel (500).

8. The regenerative cooling and heat insulation structure for the high-temperature surface of an aerospace engine according to claim 7, characterized in that, The outlet of the heat-insulated cooling passage (200) and / or the inlet of the engine body cooling passage (500) are provided with liquid collection chambers (600) to realize the collection and distribution of fuel; The connecting channel (400) is also surrounded by a support structure for supporting the heat insulation cooling channel (200) and the engine body cooling channel (500).

9. A space engine, characterized in that, The regenerative cooling and heat insulation structure includes the high-temperature surface of the aerospace engine as described in any one of claims 1 to 8.

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