Hollow interlayer material structure capable of eliminating thermal stress

Abstract

The invention belongs to the technical field of composite materials, and particularly discloses a hollow interlayer material structure capable of eliminating thermal stress, which comprises a central island, a hollow interlayer assembly arranged on the outer circumferential surface of the central island and an annular support structure arranged at the bottom of the hollow interlayer assembly, the fan-shaped piece comprises a bottom load bearing layer, a top heat insulation layer and a middle thermal stress eliminating layer, the top heat insulation layer is arranged on the top of the bottom load bearing layer, and a fan-shaped annular area is formed in the top of the bottom load bearing layer. The invention provides a hollow interlayer material structure capable of eliminating thermal stress, which adopts a hollow scheme of the interlayer material structure, namely adopts a multi-layer structure comprising a bottom load bearing layer, a top thermal insulation layer and a middle thermal stress eliminating layer, breaks through the performance bottleneck of a single material in the aspects of mechanical bearing, thermal protection and thermal matching, and improves the performance of the single material. And the requirement of constructing a porous bed plate for large-scale internal circulation boiling calcination of cement clinker is met.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a hollow sandwich material structure capable of eliminating thermal stress. Background Art

[0002] With the rapid development of modern industrial suspension calcination technology, the application field of internal circulation boiling (fluidized) bed, as the core equipment of the new generation of process, continues to expand. The selection of bed materials and structural form of the fluidized bed have an extremely important impact on the construction quality, structural safety, working state, etc. of the fluidized bed. Traditional industrial fluidized beds have relatively limited requirements for bed material performance due to their small production scale and working temperatures generally below 1200°C. However, in the process of research and development, innovation and industrial promotion of large-scale internal circulation calcination technology of cement clinker, porous bed plate materials must simultaneously meet the stringent requirements of high temperature resistance (>1200°C), oxidation resistance, thermal shock resistance, and high strength. This poses a major challenge to the construction of a new type of bed material structure that can adapt to high temperature alternating atmospheres. Under the current technical background, if a single porous bed plate material is used, the significant temperature difference between its upper and lower surfaces will cause the internal thermal tensile stress to exceed the material allowable value, leading to the risk of structural failure.

[0003] The large-scale construction of an internally circulating boiling (fluidized) bed requires the porous bed plates to operate under conditions of long-term operation with a large temperature differential between the upper (900°C to 1000°C) and lower (1300°C to 1450°C) temperatures, with a high top temperature (1300°C to 1450°C). During the design process, in addition to considering the bed plate structure's ability to bear a certain tonnage of material, the internal stress changes generated by operating in this environment must also be considered, as well as the destructive effects on the structural safety and stability. To prevent the significant temperature differential between the porous plate's internal and fluid-contacting surfaces due to heat conduction and gas convection, which could lead to excessive thermal tensile stresses (exceeding the material's allowable limit) within the material and on the pore surface, the following failure mechanism must be addressed: When the thermal tensile stress exceeds a critical value, microcracks first initiate between the pores. As the thermal stress cycles, the cracks gradually expand and interconnect, eventually forming a through-hole fracture layer. This progressive damage, caused by the accumulation of thermal stress, can directly lead to structural instability of the porous plate, seriously threatening the safe operation of the internally circulating boiling (fluidized) bed. Summary of the Invention

[0004] The purpose of the present invention is to provide a hollow interlayer material structure that can eliminate thermal stress, so as to solve the problems in the prior art of progressive damage caused by the accumulation of thermal stress during the use of porous plate materials, resulting in instability of the porous plate structure and seriously threatening the safety of the operation of the internal circulation boiling (fluidized) bed.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A hollow sandwich material structure capable of eliminating thermal stress comprises a central island, a hollow sandwich assembly disposed on the outer circumferential surface of the central island, and an annular support structure disposed at the bottom of the hollow sandwich assembly. The hollow sandwich assembly is an annular structure composed of a plurality of fan-shaped members, each fan-shaped member comprising a bottom load-bearing layer, a top heat-insulating layer, and an intermediate thermal stress-relieving layer. The top heat-insulating layer is disposed on top of the bottom load-bearing layer, a fan-shaped annular region is defined on top of the bottom load-bearing layer, and the intermediate thermal stress-relieving layer is disposed within the fan-shaped annular region.

[0007] The bottom load-bearing layer is evenly distributed with first air holes communicating with the fan-shaped area, and the top heat-insulating layer is provided with second air holes at positions corresponding to the first air holes.

[0008] The intermediate thermal stress relief layer includes a plurality of connection support structures, and air gaps are left between adjacent connection support structures. The second air holes are connected to the first air holes through the air gaps.

[0009] Furthermore, the hollow sandwich material structure capable of eliminating thermal stress further includes a heat-insulating layer, which is arranged outside the hollow sandwich component.

[0010] Furthermore, a support member is provided at the bottom of the central island.

[0011] Furthermore, a plurality of first positioning protrusions are provided at the bottom of the bottom load-bearing layer, and a first groove adapted to the first positioning protrusion is provided at the top of the annular support structure at positions corresponding to the first positioning protrusions.

[0012] Furthermore, the outer circumferential surface of the top thermal insulation layer is provided with edge connectors;

[0013] A plurality of second positioning protrusions are provided at the bottom of the edge connector, and a second groove adapted to the second positioning protrusion is provided at the top of the bottom load-bearing layer at a position corresponding to the second positioning protrusion.

[0014] Furthermore, a plurality of third positioning protrusions are provided at the bottom of the top heat-insulating layer, and a third groove adapted to the third positioning protrusion is provided at the top of the bottom load-bearing layer at a position corresponding to the third positioning protrusion.

[0015] Furthermore, the thermal expansion coefficient of the intermediate thermal stress relief layer is smaller than the thermal expansion coefficient of the bottom load bearing layer.

[0016] Furthermore, the thermal conductivity of the annular support structure is smaller than the thermal conductivity of the underlying load-bearing layer.

[0017] Furthermore, the instantaneous tolerance temperature of the intermediate thermal stress relief layer is not less than 1100°C;

[0018] The instantaneous withstand temperature of the top thermal insulation layer is not less than 1400°C;

[0019] The instantaneous withstand temperature of the bottom load-bearing layer is not less than 1100°C.

[0020] According to the hollow sandwich material structure capable of eliminating thermal stress provided by the present invention, the temperature tolerance of the middle thermal stress elimination layer is not lower than 1100°C, the temperature tolerance of the top thermal insulation layer is not lower than 1400°C, and the temperature tolerance of the bottom load-bearing layer is not lower than 1100°C; since the top thermal insulation layer is used to withstand the thermal gravity impact of the upper high-temperature powder and particle mixture, the temperature tolerance of the top thermal insulation layer is not lower than 1400°C, that is, the top thermal insulation layer has a certain high-temperature tolerance; the middle thermal stress elimination layer mainly meets the high-temperature heat conduction control, and its temperature tolerance is not lower than 1100°C; the bottom load-bearing layer mainly meets the high-temperature bearing capacity requirements, so its temperature tolerance is not lower than 1100°C; based on this, the mechanical properties of different materials under high-temperature conditions can be brought into play.

[0021] Furthermore, the thickness of the bottom load-bearing layer 2 is greater than the thickness of the top heat-insulating layer 4 .

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention provides a hollow sandwich material structure that can eliminate thermal stress. It adopts a hollow sandwich material structure scheme, that is, a multi-layer structure of a bottom load-bearing layer, a top insulation layer and an intermediate thermal stress elimination layer. It breaks through the performance bottleneck of a single material in mechanical bearing, thermal protection and thermal matching, and avoids the progressive damage caused by the accumulation of thermal stress during the use of a single material structure. The hollow sandwich material structure that eliminates thermal stress is more stable and reliable, meets the requirements of constructing a porous bed plate for large-scale internal circulation boiling calcination of cement clinker, and is conducive to ensuring the safe operation of the internal circulation boiling (fluidized) bed.

[0024] 2. The present invention provides a hollow sandwich material structure that can eliminate thermal stress. The hollow sandwich assembly is an annular structure composed of multiple fan-shaped parts, and the fan-shaped parts include a bottom load-bearing layer, a top insulation layer and an intermediate thermal stress elimination layer. A multi-layer fan-shaped structure is adopted to form a sandwich material structure, which has the characteristics of lightweight, strong load-bearing capacity, high temperature resistance, temperature change resistance, etc., and can adapt to different application scenarios.

[0025] 3. In the present invention, since the second air holes are provided on the top thermal insulation layer at positions corresponding to the first air holes, and the second air holes are connected to the first air holes, during actual use, the high-temperature gas from the bottom is transported through the first air holes to the intermediate thermal stress relief layer for remixing and is ejected from the second air holes on the top thermal insulation layer. Since the high-temperature air is remixed in the intermediate thermal stress relief layer, it can have a certain cooling effect on the bottom load-bearing layer and the intermediate thermal stress relief layer, thereby preventing the tensile strength of the material from being reduced due to excessive temperature of the bottom load-bearing layer.

[0026] 4. The present invention provides a hollow sandwich material structure capable of eliminating thermal stress, which has a simple manufacturing process and low production cost and is suitable for large-scale industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 It is a structural schematic diagram of the hollow sandwich material structure capable of eliminating thermal stress provided by the present invention.

[0029] Among them, the figures are marked as: 1. annular support structure; 2. bottom load-bearing layer; 3. middle thermal stress relief layer; 4. top insulation layer; 5. first air vent; 6. center island; 7. insulation layer; 8. support member; 9. hollow sandwich assembly; 21. fan-shaped area; 31. connection fulcrum structure; 41. second air vent; 42. edge connector. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] With the rapid development of modern industrial suspension calcination technology, the application field of internal circulation boiling (fluidized) bed, as the core equipment of the new generation of process, continues to expand. The selection of bed materials and structural form of the fluidized bed have an extremely important impact on the construction quality, structural safety, working state, etc. of the fluidized bed. Traditional industrial fluidized beds have relatively limited requirements for bed material performance due to their small production scale and working temperatures generally below 1200°C. However, in the process of research and development, innovation and industrial promotion of large-scale internal circulation calcination technology of cement clinker, porous bed plate materials must simultaneously meet the stringent requirements of high temperature resistance (>1200°C), oxidation resistance, thermal shock resistance, and high strength. This poses a major challenge to the construction of a new type of bed material structure that can adapt to high temperature alternating atmospheres. Under the current technical background, if a single porous bed plate material is used, the significant temperature difference between its upper and lower surfaces will cause the internal thermal tensile stress to exceed the material allowable value, leading to the risk of structural failure.

[0033] The large-scale construction of an internal circulation boiling (fluidized) bed requires that the porous bed plate of the bed layer be operated for a long time under conditions with a large temperature difference between the upper (900℃~1000℃) and lower (1300℃~1450℃) temperatures, and a high top temperature (1300℃~1450℃). During the design process, in addition to considering the bed plate structure's ability to bear a certain tonnage of material load, it is also necessary to consider the changes in internal stress generated by its structure working in this environment, and the destructive problems it brings to its structural safety and stability. In order to avoid the large temperature gradient between the inside of the porous plate material and the outside in contact with the fluid due to material heat conduction and gas convection, resulting in large tensile stress between the inside of the porous plate material and the surface of the hole, and the tensile stress has exceeded the allowable stress of the selected material, inevitably forming cracks between the holes. Over time, a fracture layer is formed between the holes, resulting in structural failure, leading to structural safety and stability problems of the porous plate.

[0034] Based on this, the present invention proposes a hollow interlayer material structure that can eliminate thermal stress. Its structural form matches the basic performance of the material, and can construct a porous bed plate construction that is adapted to the needs of large-scale internal circulation boiling calcined cement clinker, that is, high temperature resistance, oxidation resistance, thermal shock resistance, large dynamic and static loads, and long tolerance control requirements.

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure capable of eliminating thermal stress, comprising:

[0037] Center Island 6;

[0038] A hollow sandwich component 9 is provided on the outer circumferential surface of the central island 6;

[0039] An annular support structure 1 is provided at the bottom of the hollow sandwich assembly 9. The annular support structure 1 can be fixedly provided at the bottom of the bottom load-bearing layer 2 to support the hollow sandwich assembly 9.

[0040] Specifically, the hollow sandwich assembly 9 is an annular structure composed of a plurality of fan-shaped parts, the fan-shaped parts including a bottom load-bearing layer 2, a top heat-insulating layer 4 and an intermediate thermal stress relief layer 3. The top heat-insulating layer 4 is arranged on top of the bottom load-bearing layer 2. A fan-shaped annular area 21 is opened on the top of the bottom load-bearing layer 2. The intermediate thermal stress relief layer 3 is arranged in the fan-shaped annular area 21.

[0041] The bottom load-bearing layer 2 is evenly distributed with first air holes 5 communicating with the sector annular area 21 , and the top heat-insulating layer 4 is provided with second air holes 41 at positions corresponding to the first air holes 5 ;

[0042] The intermediate thermal stress relief layer 3 includes a plurality of connection support structures 31, with air gaps between adjacent connection support structures 31, and the second air holes 41 are connected to the first air holes 5 through the air gaps; specifically, the connection support structures 31 are rectangular parallelepiped;

[0043] In this embodiment, the various material layers (i.e., the bottom load-bearing layer 2, the top thermal insulation layer 4, and the middle thermal stress relief layer 3) are not fixedly connected, and the material layers can slide relative to each other. There is a certain expansion gap between the bottom load-bearing layer 2 and the middle thermal stress relief layer 3. Therefore, the tensile stress generated by the top thermal insulation layer 4 due to heating cannot be transmitted to the middle thermal stress relief layer 3 and the bottom load-bearing layer 2.

[0044] In this embodiment, the bottom load-bearing layer 2 and the top heat-insulating layer 4 are both fan-shaped structures, and the whole presents a fan-shaped segmented porous plate structure, with its two ends as force support points, and porous areas are set to meet the needs of working in a high-pressure airflow field; in addition, the arrangement position of the connecting fulcrum structure 31 is spatially dislocated with the second air vent 41 and the first air vent 5, so that the second air vent 41 and the first air vent 5 maintain connectivity in the vertical direction, that is, the spatial avoidance principle is adopted, so that the arrangement array position of the connecting fulcrum structure 31 and the central axis of the second air vent 41 and the first air vent 5 form a non-overlapping layout, thereby realizing contact connection and thermal isolation between layers, and retaining the connectivity between the second air vent 41 and the first air vent 5, thereby realizing its functional channel characteristics;

[0045] In this embodiment, the top layer is the top insulation layer 4, which is the insulation layer (i.e., the first layer) and is constructed of high-temperature resistant, high-strength materials to withstand the thermal gravity erosion of the high-temperature powder and particle mixture in the upper layer and the impact of the accident material. Specifically, the top insulation layer 4 must meet the following functional requirements to meet the functional requirements of high temperature resistance, impact resistance, resistance to alternating atmosphere environment influence, and wear resistance:

[0046] 1. High temperature tolerance: The long-term working temperature must be stably maintained in the range of 1300℃-1400℃, and the instantaneous tolerance temperature must not be lower than 1400℃;

[0047] 2. Mechanical performance requirements: First, resistance to thermal gravity erosion, that is, to withstand the continuous dynamic load of high-temperature powder and particle mixture (≥5MPa); second, impact resistance, that is, to withstand ≥10kN / m under accident conditions 2 Impact stress;

[0048] 3. Environmental adaptability: First, resistance to atmosphere alternation, that is, maintaining structural stability in an oxidation / reduction cycle atmosphere; second, wear resistance, that is, the surface wear rate must be ≤0.1mm / thousand hours (for powder particles with a particle size of 0.5-3mm);

[0049] The material of the top thermal insulation layer 4 includes but is not limited to any one or more of ceramic-based composite materials, metal-based composite materials, new composite materials, and special refractory materials mixed in any proportion, wherein the ceramic-based composite material can be any one or more of alumina-mullite composite ceramics, silicon carbide fiber reinforced silicon nitride ceramics, and zirconium oxide toughened alumina ceramics mixed in any proportion; the metal-based composite material can be any one or more of nickel-based high-temperature alloys, molybdenum-titanium-zirconium reinforced steel, and tungsten carbide metal ceramics mixed in any proportion; the new composite material can be a carbon-carbon composite material and / or an aerogel composite refractory brick; the special refractory material can be any one or more of corundum refractory castables, chrome corundum bricks, and magnesia-aluminum spinel refractory prefabricated parts mixed in any proportion;

[0050] The middle layer is the middle thermal stress relief layer 3, which is a thermal stress relief layer (i.e., the second layer). It uses a material with a low elastic modulus, high temperature resistance, oxidation resistance, and low thermal conductivity to eliminate the structural safety problems caused by the thermal tensile stress generated in the porous bed plate using a single structural material. It can not only reduce the thermal stress generated by high-temperature thermal expansion between the top thermal insulation layer 4 and the bottom load-bearing layer 2, but also play a certain role in guiding airflow. Specifically, the middle thermal stress relief layer 3 is located in the fan-shaped area 21, and the top of the middle thermal stress relief layer 3 is connected to the top thermal insulation layer 4, and the bottom of the middle thermal stress relief layer 3 is connected to the bottom of the fan-shaped area 21 at the top of the bottom load-bearing layer 2.

[0051] Since the second air holes 41 are connected to the first air holes 5, the structure of the intermediate thermal stress relief layer 3 is designed not to affect the connection between the second air holes 41 and the first air holes 5. That is, the second air holes 41 and the first air holes 5 can be connected through the intermediate thermal stress relief layer 3. Specifically, the intermediate thermal stress relief layer 3 includes a plurality of connection support structures 31, and air gaps are left between adjacent connection support structures 31. The second air holes 41 and the first air holes 5 are connected through the air gaps.

[0052] The material of the intermediate thermal stress relief layer 3 has the following core functions: (1) effectively blocking the heat conduction between the top layer and the bottom layer through low thermal conductivity, thereby preventing the thermal tensile stress of the structure from exceeding the allowable value of the upper and lower layers; (2) meeting the clamping load requirements of the upper and lower porous bed plates (i.e., the top thermal insulation layer 4 and the bottom load-bearing layer 2) while maintaining the connectivity of the gas channel; (3) utilizing the elastic modulus characteristics of the material to buffer the stress concentration caused by the difference in thermal expansion; (4) high-temperature gas (900℃~1100℃) can be remixed in the intermediate thermal stress relief layer 3, thereby achieving thermal insulation of the upper and lower surface layers (i.e., the top thermal insulation layer 4 and the bottom load-bearing layer 2) and thermal stress relief inside the structure;

[0053] In addition, the intermediate thermal stress relief layer 3 must meet the requirements of maintaining a long-term working temperature stably in the range of 900°C to 1100°C and an instantaneous withstand temperature of not less than 1100°C; the material of the intermediate thermal stress relief layer 3 includes but is not limited to any one or more of ceramic fiber composite materials, zirconia porous ceramics, graphite intercalation compounds, and nano aerogel felt mixed in any proportion;

[0054] The bottom layer is the bottom load bearing layer 2 (the third layer, also called the structural layer), which is made of high temperature resistant, anti-oxidation, and high strength mechanical properties materials to construct a safe support structure for a large fluidized (boiling) bed; the main material properties of the bottom load bearing layer 2 require a large thermal conductivity coefficient, and the temperature gradient of the bottom material The internal thermal stress is small, meeting the structural support requirements of the entire sandwich material structure; the bottom load-bearing layer 2 needs to meet the long-term working temperature stable maintenance in the range of 900℃ to 1100℃, and the instantaneous withstand temperature is not lower than 1100℃; the material of the bottom load-bearing layer 2 includes but is not limited to silicon carbide fiber reinforced silicon carbide ceramic matrix composite materials and / or tungsten-molybdenum alloy gradient structure;

[0055] The central island 6 and the annular support structure 1 (i.e., the fourth layer) serve as load-bearing components and are both made of high-strength structural materials with low thermal conductivity. Specifically, during actual installation, the central island 6 is placed on the central island support platform, and the annular support structure 1 is placed around it. The annular support structure 1 is placed on the surrounding annular support platforms.

[0056] The central island 6 and the annular support structure 1 (i.e., the fourth layer) must simultaneously meet the dual requirements of mechanical stability and thermal stress control. The material selection of the central island 6 and the annular support structure 1 must follow the following principles: (1) Compressive performance: they must withstand the vertical load and compressive stress from the upper structure (i.e., the bottom load-bearing layer 2, the top insulation layer 4, and the middle thermal stress relief layer 3); (2) Thermal stress control: they must have the ability to resist the thermal tensile stress caused by the temperature gradient; (3) Thermal conduction optimization: on the premise of meeting the first two requirements, the thermal conductivity should be reduced as much as possible to reduce the additional thermal stress generated by the temperature gradient between the upper and lower surfaces of the upper structure (i.e., the bottom load-bearing layer 2, the top insulation layer 4, and the middle thermal stress relief layer 3);

[0057] The material selection for the central island 6 and the annular support structure 1 is primarily intended to address the possibility of structural material damage due to thermal tensile stress generated within the structural material due to a large temperature difference between the upper and lower surfaces. The materials for the central island 6 and the annular support structure 1 include, but are not limited to, any one or more of high-temperature ceramic-based composite materials, porous metal composite plates, and oriented fiber-reinforced composite materials, mixed in any proportion.

[0058] In this embodiment, a hollow sandwich material structure scheme that can eliminate thermal stress is provided. The material of the top thermal insulation layer 4 that contacts the high temperature is made of a high-temperature resistant composite material, which mainly improves the high-temperature tolerance of the material; the middle thermal stress elimination layer 3 is made of a material with a low elastic modulus, high-temperature resistance, oxidation resistance, and low thermal conductivity, which mainly meets the high-temperature heat conduction control; the bottom load-bearing layer 2 is made of a material with high-temperature resistance, oxidation resistance, and high-strength mechanical properties, which mainly meets the high-temperature bearing capacity requirements; based on the above design, the sandwich material structure can be used to give full play to the mechanical properties of different materials under high-temperature conditions.

[0059] In addition, from the perspective of the development of bed porous plate materials, the requirements for material parameters such as thermal conductivity and elastic modulus are becoming increasingly higher. The performance of a single type of material is difficult to meet the requirements. The sandwich material structure is the development trend of future bed materials.

[0060] The hollow interlayer material structure provided in this embodiment can eliminate thermal stress, reduce the internal thermal stress of the bed plate in a high-temperature working environment, maximize the mechanical properties of the bed plate material, and increase the production scale without increasing the external dimensions of the fluidized bed. It can be applied to different usage scenarios and is the preferred bed plate structure for current industrial production of boiling (fluidized) beds.

[0061] The hollow sandwich material structure capable of eliminating thermal stress provided in this embodiment is composited with multiple layers of materials having a certain elastic modulus, thereby minimizing the thermal stress inside the structure and improving the safety and stability of the structure.

[0062] Example 2

[0063] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure capable of eliminating thermal stress. The difference from Example 1 is that in this embodiment, the hollow sandwich material structure capable of eliminating thermal stress further includes a thermal insulation layer 7, which is fixedly arranged on the outside of the hollow sandwich component 9 to keep the inside of the hollow sandwich component 9 warm.

[0064] Specifically, a fastening steel plate may be further installed on the outside of the thermal insulation layer 7 to fix the thermal insulation layer 7 and the hollow sandwich assembly 9 inside it.

[0065] Example 3

[0066] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure that can eliminate thermal stress. The difference from Example 1 is that in this embodiment, the connection support structure 31 is formed by extending from the lower surface of the top thermal insulation layer 4 and protrudes downward; the bottom end of the connection support structure 31 is connected to the bottom of the fan ring area 21;

[0067] Specifically, the upper part of the connecting fulcrum structure 31 forms an integrated structure with the top insulation layer 4, so that the lower surface of the top insulation layer 4 can produce a fixed downward protruding structure. The arrangement position of the connecting fulcrum structure 31 forms a spatial dislocation with the second air vent 41 and the first air vent 5, so that the second air vent 41 and the first air vent 5 maintain connectivity in the vertical direction.

[0068] Example 4

[0069] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure capable of eliminating thermal stress. The difference from embodiment 1 is that, in this embodiment, the connection support structure 31 is formed by the upward protrusion of the bottom of the fan-shaped area 21 on the bottom load-bearing layer 2; the top end of the connection support structure 31 is connected to the top insulation layer 4;

[0070] Specifically, the bottom of the connecting fulcrum structure 31 forms an integrated structure with the underlying load-bearing layer 2, so that a fixed upward protruding structure is generated on the fan-shaped area 21 of the underlying load-bearing layer 2. The arrangement position of the connecting fulcrum structure 31 forms a spatial dislocation with the second air vent 41 and the first air vent 5, so that the second air vent 41 and the first air vent 5 maintain connectivity in the vertical direction.

[0071] Example 5

[0072] like Figure 1As shown, this embodiment provides a hollow sandwich material structure capable of eliminating thermal stress. The difference from Example 1 is that, in this embodiment, the second fan-shaped sublayer includes a plurality of connection support structures 31. The bottom of the fan-shaped annular region 21 on the bottom load-bearing layer 2 is raised upward to form a first raised portion, and the top thermal insulation layer 4 is raised downward to form a second raised portion. The top of the first raised portion is connected to the bottom of the second raised portion to form the connection support structure 31.

[0073] Specifically, the upper part of the connecting fulcrum structure 31 forms an integrated structure with the top thermal insulation layer 4, so that a fixed downward convex structure (i.e., convex part 2) is generated on the lower surface of the top thermal insulation layer 4. The bottom of the connecting fulcrum structure 31 forms an integrated structure with the bottom load-bearing layer 2. A fixed upward convex structure (i.e., convex part 1) is generated on the fan-shaped annular area 21 of the bottom load-bearing layer 2. The top of the convex part 1 is connected to the bottom of the convex part 2 to form the connecting fulcrum structure 31. The arrangement position of the connecting fulcrum structure 31 is spatially dislocated with the second air vent 41 and the first air vent 5, so that the second air vent 41 and the first air vent 5 maintain connectivity in the vertical direction.

[0074] Example 6

[0075] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure that can eliminate thermal stress. The difference from Example 1 is that a support member 8 is provided at the bottom of the central island 6, and the top edge of the support member 8 is also in contact with the bottom of the bottom load-bearing layer 2;

[0076] A support member 8 is provided for providing central support to the central island 6 . In addition, the support member 8 can also cooperate with the annular support structure 1 to form support for the hollow sandwich assembly 9 .

[0077] Example 7

[0078] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure capable of eliminating thermal stress. The difference from embodiment 1 is that, in this embodiment, the thermal expansion coefficient of the intermediate thermal stress elimination layer 3 is smaller than the thermal expansion coefficient of the bottom load bearing layer 2;

[0079] Since the thermal expansion coefficient of the intermediate thermal stress relief layer 3 is smaller than that of the bottom load-bearing layer 2, it has the following advantages: First, it can effectively achieve thermal isolation and temperature gradient control, that is, the intermediate thermal stress relief layer 3 can effectively slow down the conduction of heat from the top to the bottom, so that the bottom temperature remains relatively low, avoiding material softening or deformation caused by high temperature, and ensuring structural stability; second, it can achieve thermal stress buffering, that is, the low thermal expansion coefficient causes the temperature gradient to be concentrated in the intermediate thermal stress relief layer 3 rather than the bottom load-bearing layer 2, reducing stress concentration between the upper and lower layers and preventing cracking or peeling; third, it can dynamically release thermal stress, that is, slow down the heat transfer rate, provide the material with a longer thermal expansion adaptation time, reduce the instantaneous thermal stress peak, and enhance the thermal fatigue resistance of the structure.

[0080] Example 8

[0081] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure that can eliminate thermal stress. The difference from embodiment 1 is that in this embodiment, the thermal conductivity of the annular support structure 1 is smaller than the thermal conductivity of the underlying load-bearing layer 2;

[0082] Since the thermal conductivity of the annular support structure 1 is lower than that of the underlying load-bearing layer 2, it has the following advantages: First, it blocks the thermal bridge effect, that is, the low thermal conductivity prevents the annular support structure 1 from becoming a heat transfer path, prevents local overheating or heat loss, and maintains the uniformity of the overall heat distribution; second, it improves thermal stability and structural integrity, that is, the annular support structure 1 can withstand mechanical loads under low thermal conductivity materials (such as high-temperature ceramic-based composite materials), while reducing deformation caused by thermal expansion mismatch, thereby improving dimensional stability in high-temperature environments; third, it optimizes system-level thermal insulation, that is, reducing heat conduction to external connection components through the annular support structure 1, thereby protecting surrounding components from high temperature.

[0083] Example 9

[0084] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure that can eliminate thermal stress. The difference from Example 1 is that in this embodiment, the thickness of the bottom load-bearing layer 2 is greater than the thickness of the top insulation layer 4. Specifically, the thickness of the bottom load-bearing layer 2 is about twice the thickness of the top insulation layer 4.

[0085] In this embodiment, the thickness of the bottom load-bearing layer 2 is greater than that of the top insulation layer 4. This is because in a traditional single porous bed plate, thermal stress is generated at 1 / 3 of the bed plate, which easily leads to local stress concentration and causes cracks or fatigue failure. By setting the thickness of the bottom load-bearing layer 2 to be approximately twice the thickness of the top insulation layer 4, the following advantages are achieved:

[0086] First, the mechanical restraint capability of the hollow sandwich material structure, which can eliminate thermal stress, on thermal expansion is enhanced, dispersing stress over a larger volume area. In addition, after functional stratification of the bottom load-bearing layer 2 and the top thermal insulation layer 4, the thermal expansion coefficient of each layer can be independently optimized, further alleviating interlayer thermal mismatch stress. In other words, each layer of material is independently selected according to functional requirements, avoiding the conflicting requirements of a single material for both thermal insulation and load-bearing, thereby improving the overall performance-cost ratio.

[0087] Second, the layered structure allows the interface between layers to absorb thermal expansion differences through micro-slip or elastic deformation, thereby suppressing crack initiation. In addition, since the thickness of the bottom load-bearing layer 2 is thicker than that of the top thermal insulation layer 4, the transfer path of thermal stress to the critical load-bearing area can be delayed, thereby extending fatigue life.

[0088] Third, it has the advantage of low maintenance cost. If there is a problem with the top insulation layer 4, the top insulation layer 4 can be replaced alone without replacing the entire bed plate, thus reducing maintenance costs. In addition, the layered design makes it easy to adjust the thickness or material of each layer according to different working conditions (such as temperature and load), thereby improving design flexibility.

[0089] Fourth, the thermal-mechanical synergistic design: the thickness of the bottom load-bearing layer 2 is thicker than that of the top insulation layer 4, which can form a heat sink effect, quickly conduct heat away from local hot spots through heat conduction, and reduce the operating temperature of the top insulation layer 4;

[0090] This layered structural design solves the problem of thermal stress concentration and functional conflict in traditional single porous bed plates, and significantly improves the reliability, life and economy of the structure under high-temperature load-bearing scenarios; it assigns thermal protection and mechanical load-bearing tasks to independently optimized substructures, achieving system-level performance breakthroughs.

[0091] Example 10

[0092] like Figure 1 As shown, this embodiment provides a hollow sandwich material structure capable of eliminating thermal stress. The difference from Example 1 is that, in this embodiment, a plurality of first positioning protrusions are provided at the bottom of the bottom load-bearing layer 2, and a first groove adapted to the first positioning protrusions is provided at the top of the annular support structure 1 at positions corresponding to the first positioning protrusions; specifically, the first positioning protrusions and the bottom load-bearing layer 2 can be integrally provided.

[0093] The outer circumferential surface of the top thermal insulation layer 4 is provided with an edge connector 42; a plurality of second positioning protrusions are provided at the bottom of the edge connector 42, and a second groove adapted to the second positioning protrusions is provided at the top of the bottom load-bearing layer 2 at positions corresponding to the second positioning protrusions; specifically, the second positioning protrusions and the edge connector 42 can be integrally provided;

[0094] A plurality of third positioning protrusions are provided at the bottom of the top thermal insulation layer 4. Specifically, the third positioning protrusions are provided at a position near the edge connector 42 at the bottom of the top thermal insulation layer 4. A third groove adapted to the third positioning protrusion is provided at a position corresponding to the third positioning protrusion at the top of the bottom load-bearing layer 2. Specifically, the third positioning protrusion and the top thermal insulation layer 4 can be provided in an integrated manner.

[0095] A first positioning protrusion and a first groove are provided between the bottom load-bearing layer 2 and the annular support structure 1, and positioning and fitting are achieved by complementary shapes. Similarly, a second positioning protrusion and a second groove are provided between the edge connector 42 and the bottom load-bearing layer 2, and positioning and fitting are achieved by complementary shapes. A third positioning protrusion and a third groove are provided between the top heat-insulating layer 4 and the bottom load-bearing layer 2, and positioning and fitting are achieved by complementary shapes.

[0096] Based on this, the design has the following advantages:

[0097] First, it improves assembly efficiency. This shape-complementary structure enables rapid guidance and positioning during the assembly process, eliminating the need for external auxiliary tools or complex calibration steps, significantly shortening assembly time and reducing the complexity of manual operations.

[0098] Second, it improves positioning accuracy. The shape-complementary design mechanically constrains the relative positions of components, eliminating the accumulated tolerances that are easily generated in traditional bolt connections or welding processes.

[0099] The third is to enhance structural stability. Through the distributed load transfer mechanism of the contact surface between the protrusion and the groove, the local concentrated stress is dispersed to the continuous support area of the groove array, avoiding plastic deformation caused by single-point overload and suppressing fretting wear of the connection interface under vibration conditions.

[0100] Fourth, anti-misassembly, this design can effectively prevent misplacement caused by misjudgment during the assembly process, and improve the reliability of system assembly;

[0101] Fifth, it is replaceable. Through this design, local structural layers can be replaced to reduce maintenance costs;

[0102] In addition, since the area where the edge connector 42 is located is a non-working area, the material of the edge connector 42 can be ordinary casting material to reduce costs.

[0103] The present invention provides a hollow sandwich material structure that can eliminate thermal stress. It adopts a hollow sandwich material structure scheme, that is, a multi-layer structure of a bottom load-bearing layer, a top insulation layer and an intermediate thermal stress elimination layer. It breaks through the performance bottleneck of a single material in mechanical bearing, thermal protection and thermal matching, and meets the needs of constructing a porous bed plate for large-scale internal circulation boiling calcined cement clinker.

[0104] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0105] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A hollow sandwich material structure capable of eliminating thermal stress, characterized in that: The invention comprises a central island (6), a hollow sandwich component (9) arranged on the outer circumferential surface of the central island (6), and an annular support structure (1) arranged at the bottom of the hollow sandwich component (9); the hollow sandwich component (9) is an annular structure composed of a plurality of fan-shaped parts; the fan-shaped parts include a bottom load-bearing layer (2), a top heat-insulating layer (4), and an intermediate thermal stress relief layer (3); the top heat-insulating layer (4) is arranged on the top of the bottom load-bearing layer (2); a fan-shaped annular region (21) is opened on the top of the bottom load-bearing layer (2); and the intermediate thermal stress relief layer (3) is arranged in the fan-shaped annular region (21); The bottom load-bearing layer (2) is evenly distributed with first air holes (5) communicating with the fan-shaped annular area (21), and the top heat-insulating layer (4) is provided with second air holes (41) at positions corresponding to the first air holes (5); The intermediate thermal stress relief layer (3) comprises a plurality of connection support structures (31), air permeable gaps are left between adjacent connection support structures (31), and the second air permeable holes (41) are connected to the first air permeable holes (5) through the air permeable gaps.

2. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: It also includes a heat-insulating layer (7), which is arranged outside the hollow sandwich component (9).

3. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: A support member (8) is provided at the bottom of the central island (6).

4. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: The bottom of the bottom load-bearing layer (2) is provided with a plurality of first positioning protrusions, and the top of the annular support structure (1) is provided with first grooves adapted to the first positioning protrusions at positions corresponding to the first positioning protrusions.

5. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: The outer circumferential surface of the top thermal insulation layer (4) is provided with an edge connector (42); The bottom of the edge connector (42) is provided with a plurality of second positioning protrusions, and the top of the bottom load-bearing layer (2) is provided with second grooves adapted to the second positioning protrusions at positions corresponding to the second positioning protrusions.

6. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: The bottom of the top heat-insulating layer (4) is provided with a plurality of third positioning protrusions, and the top of the bottom load-bearing layer (2) is provided with third grooves adapted to the third positioning protrusions at positions corresponding to the third positioning protrusions.

7. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: The thermal expansion coefficient of the intermediate thermal stress relief layer (3) is smaller than the thermal expansion coefficient of the bottom load bearing layer (2).

8. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: The thermal conductivity of the annular support structure (1) is less than the thermal conductivity of the underlying load-bearing layer (2).

9. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: The instantaneous tolerance temperature of the intermediate thermal stress relief layer (3) is not less than 1100° C.; The instantaneous withstand temperature of the top thermal insulation layer (4) is not less than 1400°C; The bottom load-bearing layer (2) has an instantaneous withstand temperature of not less than 1100°C.

10. The hollow sandwich material structure capable of eliminating thermal stress according to claim 1, characterized in that: The thickness of the bottom load-bearing layer (2) is greater than the thickness of the top heat-insulating layer (4).

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