A high-temperature resistant double-stem butterfly valve

Abstract

This application relates to the field of dual-stem butterfly valve technology, and provides a high-temperature resistant dual-stem butterfly valve, which includes a valve body, a main stem, an upper stem, a butterfly plate, and a thermal compensation structure. The main stem and the upper stem are coaxially and rotatably mounted on the valve body, and are configured to move relative to each other along their own axial direction. A compensation cavity is provided inside the butterfly plate, and the compensation cavity is filled with liquid metal. The thermal compensation structure includes an axial expansion compensation section and a radial expansion compensation section. The axial expansion compensation section is located between the main stem and the upper stem. The axial expansion compensation section includes a memory alloy skeleton and an elastic constraint member. The memory alloy skeleton has a preset phase change temperature, and when the phase change temperature is exceeded, it drives the main stem to move circumferentially through radial contraction. The radial expansion compensation section is located at the connection position between the main stem and the butterfly plate to compensate for the radial expansion of the valve body. This application effectively solves the problems of unidirectional thermal expansion compensation and thermal stress concentration at the valve stem connection in the prior art.

Description

Technical Field

[0001] This application relates to the field of double-stem butterfly valve technology, and in particular to a high-temperature resistant double-stem butterfly valve. Background Technology

[0002] Butterfly valves, as fluid control devices with simple structure and rapid opening and closing, are widely used in industrial pipeline systems. In many fields such as petroleum, chemical, and power, it is often necessary to transport and control high-temperature media. High-temperature environments not only affect the normal operation of valves but may also lead to valve sealing failure and other problems, thereby affecting the safety and stability of the entire industrial system.

[0003] In ultra-high temperature operating conditions, to address the thermal expansion issue of butterfly valves, existing high-temperature resistant double-stem butterfly valves typically employ a floating stem structure. For example, some designs utilize a structure where the main stem and upper stem can move axially relative to each other, with elastic elements at both ends of the butterfly plate to achieve vertical floating; others use disc springs to compensate for high-temperature expansion. Meanwhile, the connection between the stem and the butterfly plate is usually achieved using a fixed pin or key.

[0004] However, existing technologies have the drawback of limiting thermal expansion compensation to unidirectional axial compensation and lacking compensation for radial expansion of the valve body. Furthermore, the difference in thermal deformation on both sides of the butterfly plate caused by the non-uniform temperature field cannot be automatically balanced, the sealing specific pressure decreases with increasing temperature and is difficult to maintain constant, and thermal stress concentration at the connection between the valve stem and the butterfly plate easily leads to fatigue failure. Summary of the Invention

[0005] To address the issues of unidirectional thermal expansion compensation and thermal stress concentration at the valve stem connection in existing technologies, this application provides a high-temperature resistant double-stem butterfly valve.

[0006] The high-temperature resistant double-stem butterfly valve provided in this application adopts the following technical solution: A high-temperature resistant double valve stem includes a valve body, a main valve stem, an upper valve stem, a butterfly plate, and a thermal compensation structure; The valve body has a fluid passage inside; The main valve stem and the upper valve stem are coaxially and rotatably mounted on the valve body, and the main valve stem and the upper valve stem are configured to be movable relative to each other along their own axial direction; The butterfly plate is installed at the end of the main valve stem away from the upper valve stem; a compensation cavity is provided inside the butterfly plate, and the compensation cavity is filled with liquid metal; The thermal compensation structure includes an axial expansion compensation section and a radial expansion compensation section. The axial expansion compensation section is located between the main valve stem and the upper valve stem. The axial expansion compensation section includes a memory alloy skeleton and an elastic constraint member. The memory alloy skeleton has a preset phase change temperature, and when the phase change temperature is exceeded, it drives the main valve stem to move circumferentially through radial contraction. The radial expansion compensation section is located at the connection position between the main valve stem and the butterfly plate. The radial expansion compensation section is a radially expandable annular structure used to compensate for the change in sealing gap caused by the radial expansion of the valve body.

[0007] By adopting the above technical solution, firstly, by setting a memory alloy-containing skeleton and an axial expansion compensation section utilizing elastic constraints, under ultra-high temperature conditions, when the temperature exceeds the phase transformation temperature of the memory alloy, the memory skeleton radially contracts, generating a driving displacement that forces the main valve stem to move axially relative to the upper valve stem, thus achieving active compensation for the thermal expansion of the valve stem. Simultaneously, the radial expansion compensation section, as a stretchable annular structure, can adaptively absorb changes in the sealing gap caused by the radial expansion of the valve body, solving the problem that traditional butterfly valves can only perform unidirectional axial compensation.

[0008] Secondly, the compensation chamber filled with liquid metal within the butterfly plate utilizes the high thermal conductivity of the liquid metal to create a rapid balancing channel inside the butterfly plate. This automatically mitigates the thermal deformation differences caused by non-uniform temperature differences on both sides of the butterfly plate, maintaining a stable sealing pressure. The temperature prediction active floating control system collects temperature data in real time through multiple temperature sensors, analyzes and predicts thermal deformation trends using a deformation prediction model, and actively controls the valve stem position through an axial position adjustment mechanism. This achieves predictive adjustment of thermal expansion, solving the problem of lag in traditional compensation responses.

[0009] Optionally, the compensation cavity is enclosed, the liquid metal filling volume accounts for 60%-80% of the cavity volume, and the liquid metal is a sodium-potassium alloy, gallium-based alloy, or tin-based alloy.

[0010] By adopting the above technical solution, it is possible to ensure sufficient heat transfer medium to achieve rapid temperature uniformity, and to reserve buffer space for the thermal expansion of liquid metal, thereby compensating for excessive pressure in the cavity.

[0011] The purpose of selecting sodium-potassium alloys, gallium-based alloys, or tin-based alloys is that these alloys have a much higher thermal conductivity than solid metals, which can form an efficient thermal superconducting path inside the butterfly plate, making the temperature distribution of each part of the butterfly plate more uniform, reducing the difference in thermal deformation caused by temperature difference from the source, thereby maintaining the uniform contact pressure of the sealing pair.

[0012] Optionally, it also includes a sealing seat; the cavity wall of the fluid channel is provided with an installation groove, the installation groove is arranged around the axis of the fluid channel, the sealing seat is disposed in the installation groove, the sealing seat is coaxially arranged with the fluid channel, and the sealing seat is used to abut against the sealing surface of the butterfly plate; the sealing seat includes a sealing layer, an energy storage layer and a driving layer stacked in sequence; the sealing layer is made of a flexible material, the energy storage layer is filled with a high-temperature phase change material, and the driving layer is made of a shape memory alloy.

[0013] By adopting the above technical solution, the sealing seat uses a composite structure of a sealing layer, an energy storage layer, and a driving layer to form an adaptive sealing system. The sealing layer, made of flexible material, ensures initial sealing performance; the high-temperature phase change material in the energy storage layer absorbs a large amount of heat and undergoes volume expansion when it reaches the phase change temperature, storing the expansion energy in the energy storage layer; the driving layer is made of shape memory alloy, which generates contraction stress when the temperature rises, squeezing the energy storage layer to release the stored energy, which then acts on the sealing layer. This achieves automatic enhancement of the sealing specific pressure as the temperature rises, solving the problem of sealing specific pressure decay caused by high temperature in traditional seals.

[0014] Optionally, the driving layer is a woven mesh structure made of titanium-nickel alloy and generates shrinkage stress as the temperature rises within the range of 100°C to 600°C.

[0015] By adopting the above technical solution, the driving layer is designed as a titanium-nickel alloy braided mesh structure. Utilizing the geometric characteristics of the braided mesh and the property that the shrinkage force of titanium-nickel alloy increases with temperature over a wide temperature range of 100℃ to 600℃, a linear positive correlation between the sealing driving force and temperature is achieved. The braided mesh structure increases the contact area between the driving layer and the energy storage layer, making stress transmission more uniform and enabling precise compensation for stress relaxation of the sealing material at different temperature levels, ensuring that the sealing seat maintains a constant sealing specific pressure throughout the entire high-temperature range.

[0016] Optionally, an induction layer is provided between the sealing layer and the energy storage layer, the induction layer having a plurality of filling cavities filled with liquid metal.

[0017] By adopting the above technical solution, when the heat of the high-temperature medium attempts to be conducted to the valve body through the sealing layer, the sensing layer that is in close contact with the sealing layer will first diffuse the heat on the contact surface laterally along the filling cavity, so as to homogenize the point-like or locally concentrated high temperature and reduce the risk of local overheating damage to the sealing layer.

[0018] Optionally, the energy storage is a porous foamed ceramic skeleton, and the high-temperature phase change material fills the voids in the energy storage layer.

[0019] By adopting the above technical solution, the foamed ceramic skeleton has the characteristics of high porosity and low thermal conductivity. After the heat is homogenized by the induction layer, it continues to be transferred to the energy storage layer. At this time, the low thermal conductivity of the energy storage layer itself blocks most of the heat, while the phase change material filling the voids absorbs the remaining heat through phase change, forming a dual barrier of physical insulation and chemical insulation.

[0020] Optionally, the butterfly plate includes a low-expansion alloy layer, a medium-expansion alloy layer, and a high-expansion alloy layer from the center to the edge, and the low-expansion alloy layer, the medium-expansion alloy layer, and the high-expansion alloy layer are connected to each other by metallurgical bonding.

[0021] By adopting the above technical solution, the coefficient of thermal expansion of the butterfly plate increases sequentially from the center to the edge, so that the expansion of each layer of the butterfly plate is different when heated. Then, the low expansion layer at the center is used to constrain the overall deformation, the intermediate expansion layer is used to transition the stress, and the high expansion layer is used to compensate for the sealing gap at the edge.

[0022] Through the above design and principles, the butterfly plate generates a predetermined reverse warping deformation in the radial temperature gradient field to counteract the twisting of the sealing surface caused by thermal stress, thereby achieving self-compensation for thermal deformation. Furthermore, the layers are connected by metallurgical bonding, ensuring the continuous transmission of thermal stress and the overall strength of the structure.

[0023] Optionally, the main valve stem and the butterfly plate are connected by a cross-shaped flexible hinge, which allows ±1.5° deflection and ±0.3mm radial displacement.

[0024] By adopting the above technical solution, a flexible compensation space with multiple degrees of freedom is provided for the relative movement of the main valve stem and the butterfly plate under high temperature conditions. This absorbs the thermal stress caused by the difference in thermal expansion coefficients between the main valve stem and the butterfly plate to a certain extent, improves the problem of local stress concentration and fatigue failure caused by traditional rigid connection, and improves the fatigue life of the connection part under repeated thermal cycling.

[0025] In summary, this application includes at least one of the following beneficial technical effects: An axial expansion compensation section is set up, which includes a shape memory alloy skeleton and elastic constraint components. When the temperature exceeds the phase transformation temperature of the shape memory alloy under ultra-high temperature conditions, the shape memory skeleton radially contracts and drives the main valve stem to move axially, realizing active compensation for the thermal expansion of the valve stem. As a retractable ring structure, the radial expansion compensation section can adaptively absorb the changes in sealing gap caused by the radial expansion of the valve body, solving the problem that traditional butterfly valves can only compensate in one direction axially. The butterfly plate is filled with a compensation cavity of liquid metal. The high thermal conductivity of the liquid metal forms a rapid balance channel, which automatically adjusts the thermal deformation difference caused by the non-uniform temperature difference on both sides of the butterfly plate and maintains a stable sealing pressure. The main valve stem and the butterfly plate are connected by a cross-shaped flexible hinge, which provides a multi-degree-of-freedom flexible compensation space for the relative movement of the main valve stem and the butterfly plate under high temperature conditions. This absorbs thermal stress, improves the local stress concentration and fatigue failure problems caused by traditional rigid connections, and increases the fatigue life of the connection parts under repeated thermal cycles. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application.

[0027] Figure 2 yes Figure 1 An enlarged view at point A.

[0028] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of this application.

[0029] Figure 4 yes Figure 3 Enlarged diagram at point B Explanation of reference numerals in the attached drawings: 1. Valve body; 11. Fluid passage; 12. Mounting groove; 2. Main valve stem; 3. Upper valve stem; 4. Butterfly plate; 41. Compensation chamber; 42. Liquid metal; 43. Low-expansion alloy layer; 44. Medium-expansion alloy layer; 45. High-expansion alloy layer; 5. Thermal compensation structure; 51. Axial expansion compensation section; 511. Memory frame; 512. Elastic constraint component; 52. Radial expansion compensation section; 6. Sealing seat; 61. Sealing layer; 62. Energy storage layer; 63. Drive layer; 64. Sensing layer. Detailed Implementation

[0030] This application mainly adopts a thermal compensation structure 5 and a special butterfly plate 4 to achieve multi-directional compensation and sealing stability at high temperatures, effectively solving the problems of insufficient thermal expansion compensation and sealing pressure attenuation in high-temperature butterfly valves. The following is a further detailed description of this application.

[0031] This application discloses a high-temperature double-stem butterfly valve. Example 1

[0032] Reference Figure 1 and Figure 2 A high-temperature double-stem butterfly valve includes a valve body 1, a main stem 2, an upper stem 3, a butterfly plate 4, and a thermal compensation structure 5. The main valve stem 2 and the upper valve stem 3 are coaxially and rotatably mounted on the valve body 1, and can move relative to each other along their own axial direction. The butterfly plate 4 is fixed to the end of the main valve stem 2 away from the upper valve stem 3. The thermal compensation structure 5 includes an axial expansion compensation section 51 and a radial expansion compensation section 52. The axial expansion compensation section 51 can drive the main valve stem 2 to move at a specific temperature, and the radial expansion compensation section 52 can adaptively absorb changes in the radial sealing gap. This achieves the effect of actively compensating for the thermal expansion of the valve stem under high-temperature conditions and compensating for changes in the sealing gap caused by the radial expansion of the valve body 1.

[0033] Specifically, the valve body 1 is the basic component of the entire butterfly valve, and it has a fluid channel 11 inside, which is the path for fluid flow.

[0034] The main valve stem 2 and the upper valve stem 3 work together to control the rotation of the butterfly plate 4. One end of the main valve stem 2 is fixedly connected to the butterfly plate 4, and the other end is coaxially mounted with the upper valve stem 3 and can move axially relative to it. It can be understood that, for example, the main valve stem 2 and the upper valve stem 3 can be connected by a spline so that the main valve stem 2 and the upper valve stem 3 can rotate synchronously, thereby controlling the rotation of the butterfly plate 4.

[0035] The butterfly plate 4 is provided with a compensation cavity 41, which is enclosed. The compensation cavity 41 is filled with liquid metal 42, and the filling amount of liquid metal 42 accounts for 60%-80% of the cavity volume. This ensures that there is enough heat conduction medium in the compensation cavity 41 to achieve rapid temperature uniformity, while also reserving buffer space for the thermal expansion of liquid metal 42 to prevent the cavity of the compensation cavity 41 from being under excessive pressure.

[0036] In this embodiment, the liquid metal 42 can be selected from sodium-potassium alloys, gallium-based alloys, or tin-based alloys. These alloys have a much higher thermal conductivity than solid metals, enabling the formation of efficient thermal superconducting pathways within the butterfly plate 4, thus making the temperature distribution in different parts of the butterfly plate 4 more uniform. For example, sodium-potassium alloys have good fluidity and thermal conductivity, allowing for rapid heat transfer at high temperatures; gallium-based alloys, on the other hand, have a lower melting point and higher thermal conductivity, making them adaptable to different temperature environments.

[0037] An axial expansion compensation section 51 is disposed between the main valve stem 2 and the upper valve stem 3. The axial compensation structure includes a memory alloy skeleton 511 and elastic constraint members 512. The memory alloy skeleton 511 includes multiple arc-shaped deformation rods, the protrusions of which abut against the cavity wall of the fluid channel 11. In this embodiment, the elastic constraint member 512 is a spring, and two elastic constraint members 512 are provided, with each elastic constraint member 512 abutting against both ends of the memory alloy skeleton 511.

[0038] When the temperature exceeds its preset phase transition temperature, the memory alloy 511 will drive the main valve stem 2 to move circumferentially through radial contraction. The memory alloy can be a titanium-nickel alloy, etc., which has stable phase transition properties within a specific temperature range. The elastic constraint 512 plays a role in restraint and buffering, ensuring that the main valve stem 2 can move smoothly when the memory alloy 511 contracts.

[0039] The radial expansion compensation section 52 is located at the connection between the main valve stem 2 and the butterfly plate 4. In this embodiment, the radial expansion compensation section 52 is a radially expandable annular structure used to compensate for changes in the sealing gap caused by the radial expansion of the valve body 1. The radial expansion compensation section 52 can be made of non-metallic materials, such as rubber, which has good elasticity and compressibility and can deform under radial pressure to compensate for the gap; or it can be made of a metal bellows structure, which has high strength and good extensibility, and can adapt to gap changes of different sizes.

[0040] The butterfly plate 4 comprises, from its center to its edge, a low-expansion alloy layer 43, a medium-expansion alloy layer 44, and a high-expansion alloy layer 45, which are connected in pairs via metallurgical bonding. This structure results in a sequential increase in the coefficient of thermal expansion from the center to the edge of the butterfly plate 4, causing different expansion amounts in each layer when heated. This allows the low-expansion layer at the center to constrain overall deformation, the medium-expansion layer to provide transition stress, and the high-expansion layer to compensate for sealing gaps at the edges, thus achieving self-compensation for thermal deformation.

[0041] Furthermore, the main valve stem 2 and the butterfly plate 4 are connected by a cross-shaped flexible hinge, which allows for ±1.5° deflection and ±0.3mm radial displacement. Under high-temperature conditions, this provides a multi-degree-of-freedom flexible compensation space for the relative movement of the main valve stem 2 and the butterfly plate 4, thereby absorbing the thermal stress caused by the difference in thermal expansion coefficients between the main valve stem 2 and the butterfly plate 4 to a certain extent. This improves the problem of local stress concentration and fatigue failure caused by traditional rigid connections, and increases the fatigue life of the connection parts under repeated thermal cycles.

[0042] The implementation principle of Example 1 is as follows: Under high-temperature conditions, when the temperature exceeds the phase transformation temperature of the shape memory alloy, the shape memory skeleton 511 in the axial expansion compensation section 51 contracts radially, driving the main valve stem 2 to move axially relative to the upper valve stem 3, thereby achieving active compensation for the thermal expansion of the valve stem. The expandable annular structure of the radial expansion compensation section 52 can adaptively absorb the changes in sealing gap caused by the radial expansion of the valve body 1. The compensation cavity 41 filled with liquid metal 42 in the butterfly plate 4 utilizes the high thermal conductivity of the liquid metal 42 to balance the thermal deformation difference on both sides of the butterfly plate 4, maintaining a stable sealing specific pressure. Example 2

[0043] Reference Figure 2 and Figure 3The difference between this embodiment and Embodiment 1 is that the high-temperature double-stem butterfly valve further includes a sealing seat 6, which is sleeved outside the main valve stem 2. The cavity wall of the fluid channel 11 is provided with an installation groove 12, which is arranged around the axis of the fluid channel 11. The sealing seat 6 is disposed in the installation groove 12 and is coaxially arranged with the fluid channel 11, for the sealing surface of the butterfly plate 4 to abut against.

[0044] The sealing seat 6 includes a sealing layer 61, an energy storage layer 62, and a driving layer 63 stacked sequentially from the inside out. The sealing layer 61 is made of a flexible material, such as rubber or graphite, to ensure that the sealing layer 61 is in close contact with the sealing surface of the butterfly plate 4 in the initial state, thereby ensuring good sealing performance.

[0045] The energy storage layer 62 is filled with a high-temperature phase change material. In this embodiment, the energy storage layer 62 is a porous foamed ceramic skeleton, with the high-temperature phase change material filling the voids in the energy storage layer 62. The foamed ceramic skeleton has the characteristics of high porosity and low thermal conductivity. After heat is homogenized by the induction layer 64, it continues to be transferred to the energy storage layer 62. At this time, the low thermal conductivity of the energy storage layer 62 itself blocks most of the heat, while the phase change material filled in the voids absorbs the remaining heat through phase change, forming a dual barrier of physical insulation and chemical heat absorption.

[0046] The driving layer 63 is made of shape memory alloy with a braided mesh structure. It is made of titanium-nickel alloy and experiences shrinkage stress as the temperature rises within the range of 100℃ to 600℃. The braided mesh structure increases the contact area between the driving layer 63 and the energy storage layer 62, making stress transmission more uniform. It can accurately compensate for the stress relaxation of the sealing material at different temperature levels, ensuring that the sealing seat 6 maintains a constant sealing specific pressure throughout the high-temperature range.

[0047] Furthermore, a sensing layer 64 is provided between the sealing layer 61 and the energy storage layer 62. The sensing layer 64 has several filling cavities filled with liquid metal 42. When the heat of the high-temperature medium attempts to be conducted to the valve body 1 through the sealing layer 61, the sensing layer 64, which is in close contact with the sealing layer 61, will first diffuse the heat on the contact surface laterally along the filling cavity, homogenizing the point-like or locally concentrated high temperature, thereby reducing the risk of local overheating damage to the sealing layer 61.

[0048] The implementation principle of Example 2 is as follows: The multi-layer structure of the sealing seat 6, under high temperature, causes the driving layer 63 to contract and compress the energy storage layer 62, allowing the energy storage layer 62 to release energy and act on the sealing layer 61, thereby enhancing the sealing specific pressure. The multi-layer alloy structure of the butterfly plate 4 achieves self-compensation for thermal deformation, and the flexible hinge connection between the main valve stem 2 and the butterfly plate 4 absorbs thermal stress, solving the problems of insufficient thermal expansion compensation, attenuation of sealing specific pressure, and thermal stress concentration at the valve stem connection in existing high-temperature butterfly valves, thus improving the stability and reliability of the butterfly valve in high-temperature environments.

[0049] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-temperature resistant double-stem butterfly valve, characterized in that: It includes a valve body (1), a main valve stem (2), an upper valve stem (3), a butterfly plate (4), and a thermal compensation structure (5); The valve body (1) has a fluid channel (11) inside. The main valve stem (2) and the upper valve stem (3) are coaxially and rotatably mounted on the valve body (1), and the main valve stem (2) and the upper valve stem (3) can move relative to each other along their own axial direction; The butterfly plate (4) is fixed to the end of the main valve stem (2) away from the upper valve stem (3); a compensation cavity (41) is provided inside the butterfly plate (4), and the compensation cavity (41) is filled with liquid metal (42). The thermal compensation structure (5) includes an axial expansion compensation section (51) and a radial expansion compensation section (52); the axial expansion compensation section (51) is disposed between the main valve stem (2) and the upper valve stem (3); the axial expansion compensation section (51) includes a memory skeleton (511) made of memory alloy and an elastic constraint member (512); the memory skeleton (511) has a preset phase change temperature, and when the phase change temperature is exceeded, the main valve stem (2) is driven to move circumferentially by radial contraction; the radial expansion compensation section (52) is disposed at the connection position between the main valve stem (2) and the butterfly plate (4), and the radial expansion compensation section (52) is a radially expandable annular structure used to compensate for the change in sealing gap caused by the radial expansion of the valve body (1).

2. The high-temperature resistant double-stem butterfly valve according to claim 1, characterized in that: The compensation cavity (41) is enclosed, and the liquid metal (42) fills 60%-80% of the cavity volume. The liquid metal (42) is a sodium-potassium alloy, a gallium-based alloy, or a tin-based alloy.

3. The high-temperature resistant double-stem butterfly valve according to claim 1, characterized in that: It also includes a sealing seat (6); the cavity wall of the fluid channel (11) is provided with an installation groove (12), the installation groove (12) is arranged around the axis of the fluid channel (11), the sealing seat (6) is arranged in the installation groove (12), the sealing seat (6) is coaxially arranged with the fluid channel (11), and the sealing seat (6) is used for the sealing surface of the butterfly plate (4) to abut; the sealing seat (6) includes a sealing layer (61), an energy storage layer (62) and a driving layer (63) stacked in sequence; the sealing layer (61) is made of a flexible material, the energy storage layer (62) is filled with a high temperature phase change material, and the driving layer (63) is made of a shape memory alloy.

4. The high-temperature resistant double-stem butterfly valve according to claim 3, characterized in that: The driving layer (63) is a woven mesh structure made of titanium-nickel alloy and generates shrinkage stress as the temperature rises from 100°C to 600°C.

5. A high-temperature resistant double-stem butterfly valve according to claim 3, characterized in that: An induction layer (64) is provided between the sealing layer (61) and the energy storage layer (62). The induction layer (64) has a plurality of filling cavities, and the filling cavities are filled with liquid metal (42).

6. A high-temperature resistant double-stem butterfly valve according to claim 5, characterized in that: The energy storage is a porous foamed ceramic skeleton, and the high-temperature phase change material fills the voids in the energy storage layer (62).

7. A high-temperature resistant double-stem butterfly valve according to claim 1, characterized in that: The butterfly plate (4) includes a low-expansion alloy layer (43), a medium-expansion alloy layer (44) and a high-expansion alloy layer (45) from the center to the edge. The low-expansion alloy layer, the medium-expansion alloy layer (44) and the high-expansion alloy layer (45) are connected to each other by metallurgical bonding.

8. A high-temperature resistant double-stem butterfly valve according to claim 1, characterized in that: The main valve stem (2) and the butterfly plate (4) are connected by a cross-shaped flexible hinge, which allows for ±1.5° deflection and ±0.3mm radial displacement.

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