Intelligent composite cladding pipe with real-time monitoring and early warning regulation and control functions

Abstract

The invention relates to an intelligent composite cladding tube with real-time monitoring and early warning regulation and control functions, which comprises a compact metal layer and a SiCf / SiC composite material layer which are used as an inner layer or an outer layer of the composite cladding tube, and a flexible transition layer positioned between the compact metal layer and the SiCf / SiC composite material layer, the sensing element is a silicon dioxide optical fiber or a molybdenum-rhenium alloy thermocouple and is used for monitoring the temperature change of the reactor core, so that the flexible transition layer has a temperature sensing function. According to the structure, the phenomena of local overheating and stress concentration can be effectively inhibited, so that the operation safety and the long-term service stability of a reactor system are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear reactor fuel element. BACKGROUND

[0002] The cladding structure, as a key protection and restraint element in the nuclear reactor fuel assembly, mainly functions to maintain the geometric stability and sealing integrity of the fuel under high temperature, high irradiation and strong corrosion environment. However, the traditional cladding material is mostly single metal or ceramic system, which only has passive protection function and lacks real-time sensing and regulation ability for the operating state. In the long-term service process, affected by multiple factors such as high temperature load, irradiation damage and chemical reaction, the cladding is prone to local overheating, crack propagation, hydrogen embrittlement or interface failure, etc., which seriously threatens the safety of the nuclear fuel assembly.

[0003] At present, the research on cladding materials at home and abroad mainly focuses on the following aspects: first, the optimization of material system, including the development of metal-based (such as FeCrAl, ODS steel), ceramic-based (such as SiCf / SiC composite material) and metal-ceramic composite structure, to improve its high temperature strength, radiation resistance and chemical stability (such as CN110093546A; CN113571209A); second, the design and regulation of interface structure, by controlling the interfacial bonding mode, interface composition and residual stress distribution, to improve the overall reliability and durability of the composite layer (such as CN120015381A); third, the research on the interaction mechanism of cladding, coolant and fuel, to prevent hydrogen or radioactive material leakage under high temperature or loss of coolant accident conditions; fourth, new surface protection and coating technology (such as CN108486537A), such as using oxide coating or functional gradient material to improve the corrosion and oxidation resistance.

[0004] Although the above research has made significant progress in the optimization of nuclear cladding material performance, the existing cladding structure is still mainly passive protection, lacking the combination of structural health monitoring, self-sensing and active regulation functions. This leads to the inability to obtain and feedback the internal state of the cladding in real time under abnormal operating conditions or sudden accidents, making it difficult to take adjustment or inhibition measures in time, limiting the safety and intelligent level of the reactor system.

[0005] Therefore, the development of a multi-layer heterogeneous composite cladding structure with self-sensing and self-regulation functions has important engineering value for realizing real-time monitoring, fault warning and safety self-adaptive regulation of the operating state of the reactor. SUMMARY

[0006] The application aims to avoid the defects of the prior art and provide a multi-layer heterogeneous composite cladding structure suitable for high-temperature environment conditions, which can sense the temperature change of the cladding in real time during service, realize timely feedback and failure warning of potential problems, and effectively inhibit local overheating or stress concentration through an adaptive adjustment mechanism, thereby significantly improving the safety and stability of the reactor system and ensuring long-term safe operation of the intelligent composite cladding tube with real-time monitoring and early warning regulation and control functions.

[0007] To achieve the above object, the technical scheme adopted by the application is as follows: an intelligent composite cladding tube with real-time monitoring and early warning regulation and control functions, comprising an inner layer and an outer layer of the composite cladding tube, when the inner layer is a dense metal layer, the outer layer is a SiCf / SiC composite material layer, when the inner layer is a SiCf / SiC composite material layer, the outer layer is a dense metal layer, and a flexible transition layer located between the dense metal layer and the SiCf / SiC composite material layer, wherein a sensing element is embedded in the flexible transition layer, the sensing element is a silica optical fiber or a molybdenum-rhenium alloy thermocouple, and is used for monitoring the temperature change of the reactor core, so that the flexible transition layer has a temperature sensing function. The dense metal layer is made of a refractory metal with a density not less than 98%, a thermal conductivity of 50-130 W / (m·K), and a volume change rate of 0.1%-1% under neutron irradiation, and the refractory metal is any one of molybdenum, niobium, tantalum, molybdenum alloy, niobium alloy, tantalum alloy, and nickel alloy, and the dense metal layer is used for blocking leakage of fission products and enhancing the air tightness of the composite cladding tube. The flexible transition layer is made of a SiC whisker reinforced SiC matrix composite material with a whisker aspect ratio of 80-100, and is used for relieving thermal stress between the composite cladding layers, providing embedding space for the sensing element, and enhancing the fracture toughness of the composite cladding tube. The data acquisition device and the feedback device are further included, and the feedback device is composed of a warning device and a control cabinet connected by electricity; the data acquisition device is electrically connected with the sensing element. The warning device sends an abnormal temperature signal to the control cabinet according to the abnormal temperature collected by the data acquisition device, and the control cabinet realizes dynamic regulation and control of the reactor core temperature of the composite cladding tube by adjusting the fuel heating power and the coolant flow rate.

[0008] Further, the composite cladding tube is a 3-5 layer hollow tubular cladding tube composed of at least a dense metal layer, a flexible transition layer, and a SiCf / SiC composite material layer.

[0009] Further, the dense metal layer is prepared by hot isostatic pressing sintering or a powder metallurgy process.

[0010] Further, the sensing element is uniformly embedded in the flexible transition layer in a U-shaped or spiral structure. ​The U-shaped structure is coplanar with the flexible transition layer, the U-shaped structure is arranged along the axial extension of the composite cladding tube, and the U-shaped structure is continuously arranged in the circumferential direction of the composite cladding tube, and the circumferential pitch of the U-shaped structure is 1.0-2.0 mm. The spiral structure is coplanar with the flexible transition layer, and the spiral structure is arranged along the axial spiral extension of the composite cladding tube, and the axial pitch of the spiral structure is 1.5-2.0 mm.

[0011] Further, the flexible transition layer, wherein the volume fraction of SiC whiskers is 30%-40%, and the porosity is 20%-25%, so as to ensure that the composite cladding tube structure still has flexibility and interface bonding strength when the sensing element is embedded.

[0012] Further, the volume fraction of the silica optical fiber or the molybdenum-rhenium alloy thermocouple in the flexible transition layer is not more than 1.5%, so as to ensure the radial thermal conductivity of the composite cladding tube.

[0013] Further, the SiCf / SiC composite material layer is composed of 1-3 layers of continuous SiC fiber bundles reinforced SiC matrix, the fiber bundles are wrapped in the SiC matrix in a woven structure, the volume fraction of the fiber bundles is 30%-60%, the layer porosity is not higher than 10%, and the density is not lower than 95%, so as to enhance the high-temperature mechanical properties and structural stability of the composite cladding tube, and the tensile strength of the SiCf / SiC composite material layer is increased by at least 75% compared with that of the single SiC ceramic cladding tube, and the SiCf / SiC composite material layer and the flexible transition layer form a continuous body of SiC matrix, forming a complete composite cladding tube.

[0014] Further, the thickness of the dense metal layer in the radial direction of the composite cladding tube is 0.35-0.40 mm; the thickness of the SiCf / SiC composite material layer is 0.25-0.30 mm; and the thickness of the flexible transition layer is 0.05-0.20 mm, so that the inner wall diameter of the finally composed composite cladding tube reaches 10.0-11.0 mm, so as to reduce the risk of fission gas pressure and cladding tube creep, and shorten the heat conduction path.

[0015] Further, the service temperature of the composite cladding tube is not more than 1200 DEG C, so as to ensure that the sensing element maintains structural integrity and functional stability in a high-temperature environment.

[0016] The beneficial effects of the present application are: the present application introduces a flexible transition layer with a temperature sensing element between the dense metal and the SiCf / SiC composite material, which realizes the intelligent monitoring function of the cladding structure.

[0017] The flexible transition layer with temperature sensing function can not only relieve the thermal stress between the dense metal layer and the SiCf / SiC composite material layer, and improve the bonding performance of the heterogeneous interface, but also provide an embedding space for a sensing element (an optical fiber sensor or a thermocouple). By arranging the optical fiber or the thermocouple in the flexible transition layer with temperature sensing function, real-time monitoring and signal transmission of the cladding temperature field can be realized. Compared with the cladding without an optical fiber monitoring system, the cladding integrated with the optical fiber sensing layer can timely respond to temperature changes, realize early identification of abnormal temperature rise, and provide fault warning.

[0018] In combination with the regulation and control mechanism of the control cabinet, the structure can effectively inhibit local overheating and stress concentration, thereby significantly improving the operation safety and long-term service stability of the reactor system. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Fig. 1 is a structural schematic diagram of the intelligent composite cladding tube according to an embodiment of the present application; Figure 2 Fig. 2 is a structural schematic diagram of the intelligent composite cladding tube according to another embodiment of the present application; Figure 3 Fig. 3 is a structural schematic diagram of the intelligent composite cladding tube according to still another embodiment of the present application; Figure 4 Fig. 4 is a comparison curve of the temperature of the composite cladding tube with and without embedding of a sensing element over time; Figure 5 Fig. 5 is a comparison curve of the temperature of the silica optical fiber over time when the sensing element is embedded; Figure 6 Fig. 6 is a force-displacement comparison curve of the flexible transition layer and the porous transition layer; Figure 7 Fig. 7 is a total energy absorption comparison bar chart of the flexible transition layer and the porous transition layer. DETAILED DESCRIPTION

[0020] The principles and characteristics of the present application are described below in combination with the drawings, and the examples are only used to explain the present application, and are not used to limit the scope of the present application.

[0021] In order to achieve the above-mentioned purpose, the present application provides the following specific embodiments: Embodiment 1: As shown in the following formula (I), an intelligent composite cladding tube with real-time monitoring and early warning regulation and control functions is provided: Figure 1 Figure 1 ​As shown, it comprises a dense metal layer 1 as the inner layer of the composite cladding tube, a SiCf / SiC composite material layer 2 as the outer layer, and a flexible transition layer 3 between the dense metal layer 1 and the SiCf / SiC composite material layer 2, in which a sensing element 4 is embedded, which is a silica optical fiber for monitoring the temperature change of the core, so that the flexible transition layer has temperature sensing function; The composite cladding tube is a 3-layer hollow tubular cladding tube composed of a dense metal layer, a flexible transition layer and a SiCf / SiC composite material layer, and the thickness of the dense metal layer in the radial direction of the composite cladding tube is 0.35-0.40 mm; the thickness of the SiCf / SiC composite material layer is 0.25-0.30 mm; and the thickness of the flexible transition layer is 0.05-0.20 mm, so that the inner wall diameter of the finally composed composite cladding tube reaches 10.0-11.0 mm, so as to reduce the risk of fission gas pressure and cladding tube creep, and shorten the heat conduction path; The dense metal layer 1 is made of refractory metal with density not less than 98%, thermal conductivity of 50-130 W / (m·K), and volume change rate of 0.1%-1% under neutron irradiation, and the refractory metal is any one of molybdenum, niobium, tantalum, molybdenum alloy, niobium alloy, tantalum alloy and nickel alloy; the dense metal layer 1 is used to block the leakage of fission products and enhance the air tightness of the composite cladding tube; The flexible transition layer is made of SiC whisker reinforced SiC matrix composite material with whisker aspect ratio of 80-100, which is used to relieve the thermal stress between the composite cladding layers and provide embedding space for the sensing element, and at the same time enhance the fracture toughness of the composite cladding tube; The sensing element is uniformly embedded in the flexible transition layer in a spiral structure, and the spiral structure is coplanar with the flexible transition layer, and the spiral structure extends along the axial direction of the composite cladding tube, and the axial pitch of the spiral structure is 1.5-2.0 mm; The process of embedding the sensing element in the flexible transition layer is as follows: (1) A protective sleeve made of SiC ceramic is sleeved on the outside of the sensing element, the inner diameter of the protective sleeve is 0.05-0.1 mm, and the outer wall surface of the protective sleeve is coated with a SiC coating with a thickness of 5-10 μm; (2) The sensing element with the protective sleeve sleeved in step (1) is embedded in the flexible transition layer, and the sensing element is supported and positioned by the SiC whiskers in the flexible transition layer; (3) The sensing element positioned in step (2) is point-fixed at both ends by SiC ceramic slurry, and sintering or densification treatment is carried out at 900-1200 ℃ for 20-30 h, and after cooling to room temperature, the flexible transition layer with the embedded sensing element is obtained; The SiCf / SiC composite material layer is composed of 1-3 layers of continuous SiC fiber bundles reinforced SiC matrix, the fiber bundles are wrapped in the SiC matrix in a woven structure, the volume fraction of the fiber bundles is 30%-60%, the layer porosity is not higher than 10%, and the density is not lower than 95%, which is used to enhance the high-temperature mechanical properties and structural stability of the composite cladding tube, and compared with the tensile strength of the single SiC ceramic cladding tube, the tensile strength of the composite cladding tube is increased by at least 75%, and meanwhile, the SiCf / SiC composite material layer and the flexible transition layer form a continuous body of SiC matrix, forming a complete composite cladding tube; The data acquisition device and the feedback device are further included, the feedback device is composed of an early warning device and a control cabinet connected by electricity, and the data acquisition device is connected with the sensing element by electricity; The early warning device sends an abnormal temperature signal to the control cabinet according to the abnormal temperature collected by the data acquisition device, and the control cabinet realizes dynamic regulation and control of the temperature of the composite cladding tube through adjusting the fuel heating power and the coolant flow rate. The service temperature of the finally obtained composite cladding tube is not more than 1200 DEG C, so as to ensure that the sensing element maintains structural integrity and functional stability in a high-temperature environment.

[0022] Embodiment 2: the same as embodiment 1, except that as shown in Figure 2 the dense metal layer 1 as the inner layer of the composite cladding tube and the SiCf / SiC composite material layer 2 as the outer layer, and the flexible transition layer 3 located between the dense metal layer 1 and the SiCf / SiC composite material layer 2, and the sensing element 4 embedded in the flexible transition layer 3, the sensing element 4 is a silica optical fiber, which is used to monitor the change of the core temperature, so that the flexible transition layer has temperature sensing function; The composite cladding tube is a three-layer hollow tubular cladding tube composed of a dense metal layer, a flexible transition layer and a SiCf / SiC composite material layer; The sensing element is uniformly embedded in the flexible transition layer in a U-shaped structure, and the U-shaped structure is coplanar with the flexible transition layer, the U-shaped structure extends along the axial direction of the composite cladding tube, and is continuously arranged in the circumferential direction of the composite cladding tube, and the circumferential pitch of the U-shaped structure is 1.0-2.0mm.

[0023] Embodiment 3: the same as embodiment 1, except that as shown in Figure 3 the dense metal layer 1 as the outer layer of the composite cladding tube and the SiCf / SiC composite material layer 2 as the inner layer, and the flexible transition layer 3 located between the dense metal layer 1 and the SiCf / SiC composite material layer 2, and the sensing element 4 embedded in the flexible transition layer 3, the sensing element 4 is a silica optical fiber, which is used to monitor the change of the core temperature, so that the flexible transition layer has temperature sensing function; The composite cladding tube is a 4-layer hollow tubular cladding tube composed of at least one dense metal layer, one flexible transition layer and two SiCf / SiC composite material layers; The sensing element is uniformly embedded in the flexible transition layer in a spiral structure, the spiral structure is coplanar with the flexible transition layer, and the spiral structure extends along the axial direction of the composite cladding tube, and the axial pitch of the spiral structure is 1.5-2.0 mm.

[0024] Example 4: The same as example 1, except that the dense metal layer is prepared by hot isostatic sintering or powder metallurgy process.

[0025] Example 5: The same as example 1, except that the volume fraction of SiC whiskers in the flexible transition layer is 30%-40%, and the porosity is 20%-25%, so as to ensure that the composite cladding tube structure still has flexibility and interface bonding strength when the sensing element is embedded; The volume fraction of silica optical fiber or molybdenum-rhenium alloy thermocouple in the flexible transition layer is not more than 1.5%, so as to ensure the radial thermal conductivity of the composite cladding tube.

[0026] As shown in Figure 1 and Figures 4-7 To further illustrate the technical solutions and technical effects of the present application, the following specific examples are provided: As shown in Figure 1 A smart composite cladding tube with real-time monitoring and early warning control function, which is composed of 3 layers of thin-walled hollow tubular materials, from the inner layer to the outer layer, in order: a dense metal layer, a flexible transition layer with temperature sensing function, and a SiCf / SiC composite material layer; The dense metal layer is prepared by hot isostatic sintering process of molybdenum alloy, and the density is not less than 98%. The metal layer acts as a fuel contact layer, has high thermal conductivity and excellent radiation resistance, blocks the leakage of fission products and prevents chemical reaction between the fuel and the composite cladding tube; The flexible transition layer with temperature sensing function is located between the dense metal layer and the SiCf / SiC composite material layer, which is used to relieve the thermal stress between the layers and provide embedding space for the sensing element; The temperature sensing system is composed of silica optical fiber, the sensing element is uniformly embedded in the flexible transition layer in a spiral structure, and is electrically connected with the data acquisition device. The alarm sends an abnormal temperature signal to the control cabinet according to the abnormal temperature collected by the data acquisition device, and the control cabinet realizes dynamic regulation and control of the temperature of the composite cladding tube core by adjusting the fuel heating power and the coolant flow rate. The system can monitor the temperature distribution and change state of the composite cladding tube structure in the service process in real time, and realize timely early warning and regulation of abnormal temperature.

[0027] The volume fraction of SiC whiskers in the flexible transition layer with temperature sensing function is 30%, and the porosity is 20%, so that the composite cladding tube structure has good flexibility and interface bonding strength when embedding the silica optical fiber sensing element.

[0028] The volume fraction of silica optical fiber in the flexible transition layer with temperature sensing function should not exceed 1.5%, so that the composite cladding tube has good radial thermal conductivity.

[0029] The SiCf / SiC composite material layer is composed of one layer of continuous SiC fiber bundle reinforced SiC matrix, and the fiber bundle is wrapped in the SiC matrix in a woven structure, and the volume fraction of the fiber bundle is 30% to 60%, the layer porosity is not higher than 10%, and the density is not less than 95%, which is used to enhance the high temperature mechanical properties and structural stability of the composite cladding tube, and is well combined with the flexible transition layer with temperature sensing function, and the final early warning device sends an abnormal temperature signal to the control cabinet according to the abnormal temperature collected by the data acquisition device, and the control cabinet realizes dynamic regulation and control of the temperature of the composite cladding tube core by adjusting the fuel heating power and the flow rate of the coolant, as shown in Figure 4 .

[0030] The inner wall diameter of the composite cladding tube is 10.0 to 11.0 mm, which is used to reduce the risk of fissure gas pressure and cladding tube creep, and shorten the heat conduction path; the thickness of the dense metal layer in the radial direction of the cladding tube is 0.35 to 0.40 mm, the thickness of the flexible transition layer is 0.05 to 0.20 mm, and the thickness of the SiCf / SiC composite material layer is 0.25 to 0.30 mm.

[0031] The design service temperature of the composite cladding tube does not exceed 1200 ℃ (as shown in Figure 4 ), so as to ensure that the silica optical fiber sensing element embedded therein maintains structural integrity and functional stability (as shown in Figure 5 ) at a high temperature of 900 ℃.

[0032] In order to further illustrate the technical scheme and technical effect of the present application, the total energy absorption of the flexible transition layer under the axial tension working condition is quantified and analyzed from the theoretical calculation point of view by using the finite element numerical simulation method. In order to further embody the beneficial effects of the technical scheme of the present application, on the basis of the above numerical simulation, a control group structure is constructed, that is, a porous transition layer (without introducing SiC whisker reinforced SiC matrix transition intermediate layer), and under the same boundary conditions and load working conditions, the same finite element simulation method is used to calculate and analyze the total energy absorption of the control group structure.

[0033] As shown in Figure 6As shown in the force-displacement curves of the flexible transition layer and the porous transition layer obtained in the numerical simulation, the total absorption energy can be obtained by integrating the external force-displacement relationship, and the calculation method is Wherein EA is the total absorption energy value, s is the displacement value, and F is the applied force value. The calculation results show that the total absorption energy of the flexible transition layer is increased by about 27% compared with the porous transition layer under the same working conditions, thereby indicating that the flexible transition layer structure has better fracture toughness performance, as shown in Figure 7 .

[0034] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. 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 smart composite cladding tube with real-time monitoring and pre-alarm control function, characterized in that, The composite cladding tube comprises an inner layer and an outer layer; when the inner layer is a dense metal layer, the outer layer is a SiCf / SiC composite material layer; when the inner layer is a SiCf / SiC composite material layer, the outer layer is a dense metal layer; A flexible transition layer is located between the dense metal layer and the SiCf / SiC composite material layer, and a sensing element is embedded in the flexible transition layer, the sensing element is a silica optical fiber or a molybdenum-rhenium alloy thermocouple, which is used for monitoring the change of the core temperature, so that the flexible transition layer has a temperature sensing function; The dense metal layer is made of a refractory metal with a density of not less than 98%, a thermal conductivity of 50-130 W / (m·K), and a volume change rate of 0.1%-1% under neutron irradiation, the refractory metal is any one of molybdenum, niobium, tantalum, molybdenum alloy, niobium alloy, tantalum alloy, and nickel alloy, and the dense metal layer is used for blocking leakage of fission products and enhancing the air tightness of the composite cladding tube; The flexible transition layer is made of SiC whisker reinforced SiC matrix composite material with a whisker aspect ratio of 80-100, which is used for relieving thermal stress between the composite cladding layers, providing embedding space for the sensing element, and enhancing the fracture toughness of the composite cladding tube; The data acquisition device and the feedback device are further included, the feedback device is composed of an early warning device and a control cabinet connected by electricity, and the data acquisition device is electrically connected with the sensing element; The early warning device sends an abnormal temperature signal to the control cabinet according to the abnormal temperature collected by the data acquisition device, and the control cabinet realizes dynamic regulation and control of the core temperature of the composite cladding tube by adjusting the fuel heating power and the coolant flow rate.

2. The intelligent composite cladding tube with real-time monitoring and pre-alarm control functions according to claim 1, characterized in that, The composite cladding tube is a 3-5 layer hollow tubular cladding tube composed of a dense metal layer, a flexible transition layer, and a SiCf / SiC composite material layer.

3. The intelligent composite cladding tube with real-time monitoring and pre-alarm control functions according to claim 1, characterized in that, The dense metal layer is prepared by hot isostatic pressing sintering or powder metallurgy process.

4. The intelligent composite cladding tube with real-time monitoring and pre-alarm control functions according to claim 1, characterized in that, The sensing element is uniformly embedded in the flexible transition layer in a U-shaped or spiral structure; The U-shaped structure is coplanar with the flexible transition layer, the U-shaped structure extends along the axial direction of the composite cladding tube, and is continuously arranged in the circumferential direction of the composite cladding tube, and the circumferential pitch of the U-shaped structure is 1.0-2.0 mm; The spiral structure is coplanar with the flexible transition layer, and the spiral structure extends along the axial direction of the composite cladding tube, and the axial pitch of the spiral structure is 1.5-2.0 mm.

5. The intelligent composite cladding tube with real-time monitoring and pre-alarm control functions according to claim 1, characterized in that, The volume fraction of SiC whiskers in the flexible transition layer is 30%-40%, and the porosity is 20%-25%, so as to ensure that the composite cladding tube structure still has flexibility and interface bonding strength when the sensing element is embedded.

6. The intelligent composite cladding tube with real-time monitoring and pre-alarm control functions according to claim 1, characterized in that, The volume fraction of the silica optical fiber or the molybdenum-rhenium alloy thermocouple in the flexible transition layer is not more than 1.5%, so as to ensure the radial thermal conductivity of the composite cladding tube.

7. The intelligent composite cladding tube with real-time monitoring and pre-alarm control functions according to claim 1, characterized in that, The SiCf / SiC composite material layer is composed of 1-3 layers of continuous SiC fiber bundles reinforced SiC matrix, the fiber bundles are coated in the SiC matrix in a woven structure, the volume fraction of the fiber bundles is 30%-60%, the layer porosity is not higher than 10%, the density is not lower than 95%, which is used for enhancing the high-temperature mechanical properties and structural stability of the composite cladding tube, at the same time, the SiCf / SiC composite material layer and the flexible transition layer form a continuous body of SiC matrix, forming a complete composite cladding tube.

8. The intelligent composite cladding tube with real-time monitoring and pre-alarm control functions according to claim 1, characterized in that, The thickness of the dense metal layer in the radial direction of the composite cladding tube is 0.35-0.40 mm; the thickness of the SiCf / SiC composite material layer is 0.25-0.30 mm; the thickness of the flexible transition layer is 0.05-0.20 mm, so that the inner wall diameter of the finally composed composite cladding tube reaches 10.0-11.0 mm, so as to reduce the fissure gas pressure and the risk of cladding tube creep, and shorten the heat conduction path.

9. The intelligent composite cladding tube with real-time monitoring and pre-alarm control functions according to any one of claims 1-8, characterized in that, The service temperature of the composite cladding tube is not more than 1200 ℃, so as to ensure that the sensing element maintains structural integrity and functional stability in a high-temperature environment.

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