Heat preservation device for fused salt valve

Abstract

The utility model relates to the technical field of molten salt valves, in particular to a heat preservation device for a molten salt valve, which comprises a first semi-ring-shaped heat preservation body and a second semi-ring-shaped heat preservation body which can be selectively locked, and the heat preservation device can be switched between an open state and a closed state; when the first semi-ring-shaped heat preservation body and the second semi-ring-shaped heat preservation body are locked, the heat preservation device is in a closed state, the heat preservation device forms an annular structure and can cover the area between the valve executing mechanism and the valve heat preservation tank, the upper end of the heat preservation device is connected with the bottom of the valve executing mechanism, and the lower end of the heat preservation device is connected with the top of the valve heat preservation tank. Therefore, the heat of the area is effectively preserved; when the first semi-ring-shaped heat preservation body and the second semi-ring-shaped heat preservation body are unlocked, the heat preservation device is in an open state, the heat preservation device can expose the area between the valve executing mechanism and the valve heat preservation tank and can also be disassembled and assembled from the molten salt valve, and the convenience of equipment maintenance and overhaul is improved.

Description

Technical Field

[0001] This utility model relates to the field of molten salt valve technology, and in particular to a heat preservation device for molten salt valves. Background Technology

[0002] Tower-type molten salt thermal absorption and storage systems represent the most promising solar thermal power generation technology. The energy conversion principle involves converting solar energy into thermal energy, thermal energy into mechanical energy, and mechanical energy into electrical energy. Specifically, tower-type molten salt thermal power generation systems are used to achieve these conversion processes.

[0003] A tower-type molten salt solar thermal power generation system consists of three parts: a heliostat field, a molten salt system, and a power generation system. The molten salt system further comprises a heat absorption system (cold salt absorbs heat to become hot molten salt), a heat storage system (stores the hot molten salt), and a steam generation system (the hot molten salt heats water into steam). The heliostat field concentrates sunlight onto the top of the heat absorption tower in the heat absorption system. Cold salt is transported from a cold salt tank to the heat absorption tower, where it absorbs heat and becomes hot molten salt. The hot molten salt then descends the tower by gravity and is stored in the hot salt tank of the heat storage system. During the daytime operation of the heat absorption tower, the hot molten salt is transported to the steam generation system to exchange heat with water / steam, generating high-temperature, high-pressure superheated steam for power generation. After releasing heat, the hot molten salt returns to the cold salt tank, completing the entire molten salt cycle. In the operation of the solar thermal power plant, the molten salt valve operation refers to the process of supplying molten salt from the cold salt tank to the heat absorber, ensuring that there is sufficient molten salt in the system to absorb and store solar heat. In the morning or when the system restarts, the molten salt pump is started and the molten salt valve is gradually opened to smoothly deliver molten salt at a suitable temperature to the target location. At the same time, the flow rate, temperature and pressure are monitored in real time to ensure the safe and efficient operation of the system.

[0004] The molten salts involved are generally binary molten salts, composed of 60% NaNO3 and 40% KNO3 by mass, commonly known as solar salts. This salt has a freezing point of 220℃, a maximum temperature resistance of 620℃, and an actual operating temperature range of 290–565℃. Due to its high freezing point, to prevent localized flow dead zones or freezing during shutdowns, the molten salt working fluid pipelines, valve bodies, and equipment are typically insulated, and the temperature is monitored.

[0005] The aforementioned molten salt valve typically includes a valve body, valve stem, packing gland, and sealing packing. A valve actuator is mounted on the upper side of the molten salt valve, and a valve insulation tank is mounted on the outer side. The valve body has a first flow channel and a second flow channel extending inwards at both ends. Inside the valve body is a flow chamber connecting the first and second flow channels. A valve neck is located at the upper part of the valve body, and a pressure cover is installed on the upper end of the valve neck. The valve stem passes through the pressure cover and extends into the flow chamber, where it is linked with the valve disc. A valve seat is located at the junction of the flow chamber and the first flow channel to form a sealing fit with the valve disc. A bracket is mounted on the upper end of the pressure cover, and the valve actuator is mounted on the bracket. The upper end of the valve stem is linked to the output end of the valve actuator. The valve actuator adjusts the opening degree of the valve body by controlling the movement of the valve stem. The pressure cover has a sealing cavity coaxial with the valve stem in its center. Sealing packing and packing gaskets are sequentially arranged in the sealing cavity from top to bottom. The packing gland is connected to the valve neck by bolts and presses the packing sleeve onto the upper end of the sealing packing. The packing gland, packing sleeve, and sealing packing are used to seal the gap between the pressure cover and the valve stem. Molten salt is corrosive, and prolonged operation can lead to a decline in the performance of the seals or the pressure inside the valve exceeding the seals' tolerance. Molten salt may leak from the connection points between moving and stationary parts (i.e., the gap between the valve stem and the pressure cover, and the gap between the pressure cover and the valve neck).

[0006] Molten salt in the valves of solar thermal power plants is prone to leakage from the packing gland during flow. After solidification and crystallization, the molten salt blocks the gap between the valve stem and the pressure plate, increasing resistance during stem movement. This resistance can cause the valve to fail to open or close properly when the valve actuator adjusts the valve opening via the valve stem, leading to valve jamming and other problems. In emergency situations requiring salt drainage from the heat absorption tower, if the valve cannot open normally, it can cause blockage of the heat absorption tower tube screen, with molten salt solidifying inside, resulting in significant economic losses. However, in actual operation, it is usually necessary to observe whether the molten salt valve is leaking and check its condition from the area between the valve actuator (located in the packing gland) and the insulation tank, neglecting the insulation issue in this area. Utility Model Content

[0007] (a) Technical problems to be solved

[0008] In view of the above-mentioned shortcomings and deficiencies of the prior art, this utility model provides a heat preservation device for molten salt valves that can both avoid the inability to adjust the valve due to the packing gland being blocked and facilitate maintenance and inspection.

[0009] (II) Technical Solution

[0010] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0011] This utility model provides a heat preservation device for a molten salt valve. The heat preservation device includes a first semi-annular heat preservation body and a second semi-annular heat preservation body that can be selectively locked. The heat preservation device can switch between an open state and a closed state. When the first semi-annular heat preservation body and the second semi-annular heat preservation body are locked, the heat preservation device is in the closed state. The heat preservation device forms a ring structure that can cover the area between the valve actuator and the valve heat preservation tank. Its upper end is connected to the bottom of the valve actuator, and its lower end is connected to the top of the valve heat preservation tank. When the first semi-annular heat preservation body and the second semi-annular heat preservation body are released, the heat preservation device is in the open state. The heat preservation device can expose the area between the valve actuator and the valve heat preservation tank and can also be detached from the molten salt valve.

[0012] Optionally, one end of the first semi-annular insulation body and the second semi-annular insulation body are hinged together, and the other end is respectively provided with a first connector and a second connector. The first connector and the second connector are detachably connected. By rotating the first semi-annular insulation body and the second semi-annular insulation body around the hinge, the insulation device can switch between an open state and a closed state. When the first semi-annular insulation body and the second semi-annular insulation body are connected by the first connector and the second connector, the insulation device is in a closed state. When the first connector and the second connector are separated, the first semi-annular insulation body and the second semi-annular insulation body rotate around their hinge to open, and the insulation device is in an open state.

[0013] Optionally, the first semi-annular insulation body includes a first semi-annular shell and a first semi-annular insulation box filled with insulation material. The first semi-annular insulation box is fitted and fixed to the inner side of the first semi-annular shell, and the height of the first semi-annular insulation box is lower than the height of the first semi-annular shell. A first connector is connected to the outer wall of the first semi-annular shell. The second semi-annular insulation body includes a second semi-annular shell and a second semi-annular insulation box filled with insulation material. The second semi-annular insulation box is fitted and fixed to the inner side of the second semi-annular shell, and the height of the second semi-annular insulation box is lower than the height of the second semi-annular shell. A second connector is connected to the outer wall of the second semi-annular shell. When the insulation device is in the closed state, the top and bottom ends of the first semi-annular shell and the top and bottom ends of the second semi-annular shell respectively abut against the valve actuator and the valve insulation tank. The first semi-annular insulation box and the second semi-annular insulation box can face the area between the valve actuator and the valve insulation tank.

[0014] Optionally, the first semi-annular insulation box and the second semi-annular insulation box have removable lids to open or close the box cavities of the first semi-annular insulation box and the second semi-annular insulation box used for filling insulation material.

[0015] Optionally, at least one of the adjacent end walls of the first semi-annular insulation box and the second semi-annular insulation box is provided with a compressible seal. When the insulation device is in the closed state, the adjacent end walls of the first semi-annular insulation box and the second semi-annular insulation box clamp the compressible seal. The compressible seal is made of insulation material.

[0016] Optionally, a first semi-annular insulation layer with a form-fitting shape is fixed to the lower part of the inner peripheral wall of the first semi-annular insulation box, and a second semi-annular insulation layer with a form-fitting shape is fixed to the lower part of the inner peripheral wall of the second semi-annular insulation box. When the insulation device is in the closed state, the first and second semi-annular insulation layers are in contact with the packing gland of the molten salt valve. A third semi-annular insulation layer with a form-fitting shape is fixed to the inner wall of the first semi-annular shell, and the third semi-annular insulation layer is adjacent to the upper part of the first semi-annular insulation box. A fourth semi-annular insulation layer with a form-fitting shape is fixed to the inner wall of the second semi-annular shell, and the fourth semi-annular insulation layer is adjacent to the upper part of the second semi-annular insulation box. When the insulation device is in the closed state, the third and fourth semi-annular insulation layers are in contact with the bottom end of the valve actuator. Optionally, the first and second semi-annular shells are made of metal; the first and second semi-annular insulation boxes are made of metal, and the insulation material inside is insulation cotton; the materials of the compressible seal, the first semi-annular insulation layer, the second semi-annular insulation layer, the third semi-annular insulation layer, and the fourth semi-annular insulation layer are selected from aerogel, aluminum silicate, ceramic fiber, and high-silica cloth.

[0017] Optionally, when the insulation device is in the closed state, the end of the first semi-annular shell away from the hinge overlaps the outer wall of the second semi-annular shell, and the width of the overlap area is greater than or equal to 10 mm.

[0018] Optionally, the first connector and the second connector are a latch and a self-tapping screw that can overlap with the latch, respectively.

[0019] Optionally, the molten salt valve is a molten salt valve used in concentrated solar power plants.

[0020] (III) Beneficial Effects

[0021] The beneficial effects of this utility model are as follows: The insulation device for molten salt valves of this utility model can freely switch between open and closed states through a selectively lockable first and second semi-annular insulation body. When the two semi-annular insulation bodies are locked, the insulation device forms a ring structure that can cover and insulate the area between the valve actuator and the valve insulation tank. Its upper end is connected to the bottom of the valve actuator, and its lower end is close to the top of the valve insulation tank, thereby achieving effective insulation. When it is necessary to replace or repair the valve actuator or the valve insulation tank, simply release the lock of the two semi-annular insulation bodies, and the insulation device can be opened, easily exposing the area to be operated, and enabling quick disassembly and assembly of the insulation body, thus improving the convenience of equipment maintenance and repair. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a heat preservation device for molten salt valves according to the present invention.

[0023] Figure 2 This is a schematic diagram of the back structure of a heat preservation device for a molten salt valve according to the present invention;

[0024] Figure 3 for Figure 1 The diagram shows a cross-sectional view of a heat preservation device for a molten salt valve installed on the molten salt valve along the direction perpendicular to the latch to the hinge.

[0025] Explanation of reference numerals in the attached figures

[0026] A: Valve actuator; B: Valve insulation tank; C: Packing gland;

[0027] 1: First semi-annular insulation body; 11: First semi-annular shell; 12: First semi-annular insulation box; 13: First semi-annular insulation layer; 14: Third semi-annular insulation layer;

[0028] 2: Second semi-annular insulation body; 21: Second semi-annular shell; 22: Second semi-annular insulation box; 23: Second semi-annular insulation layer; 24: Fourth semi-annular insulation layer;

[0029] 3: Hook and loop fastener; 4: Self-tapping screw; 5: Compressible seal. Detailed Implementation

[0030] To better explain and facilitate understanding of this utility model, a detailed description of its specific embodiments is provided below with reference to the accompanying drawings. In this document, directional terms such as "upper," "lower," "inner," and "outer" are used interchangeably with other directional terms. Figure 1 The orientation is used as a reference.

[0031] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0032] Example 1:

[0033] Reference Figure 1 , Figure 2 and Figure 3 This embodiment provides a heat preservation device for a molten salt valve. First, let's introduce the molten salt valve. The molten salt valve is used in concentrated solar power (CSP) plants. Specifically, it is a key regulating device for transferring molten salt between the cold salt tank, the heat absorber, the hot salt tank, and the steam generator in a CSP plant. The molten salt valve has a valve actuator A installed on its upper side, a valve insulation tank B installed on its outer side, and a packing gland C in the middle. Specifically, the valve actuator A controls the opening and closing of the valve and regulates the flow rate of the molten salt. The valve insulation tank B is used to insulate the valve body. The reason why the valve insulation tank B does not cover the bottom of the valve actuator A is that the gap between the packing gland C, the sealing packing, and the valve stem needs to be manually inspected and maintained. If necessary, the sealing performance can be restored by replacing the sealing packing to ensure normal valve operation. This utility model does not improve existing molten salt valves; it only installs a suitable heat preservation device on them. Therefore, the specific structure of the molten salt valve will not be described in detail. Furthermore, this invention is not limited to molten salt valves in solar thermal power plants, but can also be applied to any other similar valves that need to maintain a stable medium temperature and prevent condensation or freezing, such as steam valves, hot water valves, or other high-temperature fluid control devices in industries such as petrochemicals, pharmaceuticals, and food processing.

[0034] The insulation device of this embodiment includes a first semi-annular insulation body 1 and a second semi-annular insulation body 2 that can be selectively locked. This design allows the insulation device to switch between an open and closed state. When the first semi-annular insulation body 1 and the second semi-annular insulation body 2 are locked, the insulation device is in the closed state. The insulation device forms a ring structure that covers the area between the valve actuator A and the valve insulation tank B, with its upper end connected to the bottom of the valve actuator A and its lower end connected to the top of the valve insulation tank B. When the first semi-annular insulation body 1 and the second semi-annular insulation body 2 are released, the insulation device is in the open state, exposing the area between the valve actuator A and the valve insulation tank B, and can also be detached from the molten salt valve.

[0035] When the two semi-annular insulation bodies are locked, the insulation device forms a ring structure that covers and insulates the area between valve actuator A and valve insulation tank B. Its upper end connects to the bottom of valve actuator A, and its lower end is tightly attached to the top of valve insulation tank B, thus achieving effective insulation. When it is necessary to replace or repair valve actuator A, valve insulation tank B, or the area between them, simply unlock the two semi-annular insulation bodies. The insulation device can then be opened, easily exposing the area to be operated on and allowing for quick disassembly and assembly of the insulation bodies, improving the convenience of equipment maintenance and repair.

[0036] Specifically, see Figure 1 and Figure 2 The first semi-annular insulation body 1 includes a first semi-annular shell 11 and a first semi-annular insulation box 12 adapted to its shape. The first semi-annular insulation box 12 is located inside the first semi-annular shell 11, and the outer wall of the first semi-annular insulation box 12 is attached to the inner wall of the first semi-annular shell 11. The height of the first semi-annular insulation box 12 is lower than the height of the first semi-annular shell 11. The first semi-annular insulation box 12 has a removable lid to open or close the box cavity, which is filled with insulation material. Long-term use of the insulation material may lead to a decrease in insulation effect. The removable lid facilitates the inspection of the insulation material's condition. If the material performance deteriorates, the lid can be removed to replace the insulation material in the box, ensuring that the insulation device maintains good insulation performance.

[0037] More specifically, the first semi-annular shell 11 and the first semi-annular insulation box 12 can be made of metal, such as stainless steel and aluminum alloy. The first semi-annular shell 11 and the first semi-annular insulation box 12 can be fixed by nailing, welding or other methods, but are not limited to metal materials. Other materials that can withstand high temperatures and have sufficient mechanical strength can also be used as substitutes, such as high-temperature ceramics and composite materials, and fixed in an appropriate manner. The insulation material filled in the insulation box can be insulation cotton, such as aluminum silicate cotton, heat-insulating glass wool and heat-insulating pearl cotton, but is not limited to insulation cotton. Other materials that can play a heat-insulating role for molten salt can be used as substitutes.

[0038] Furthermore, a shape-fitting first semi-annular insulation layer 13 is fixed to the lower part of the inner peripheral wall of the first semi-annular insulation box 12, and the outer peripheral wall of the first semi-annular insulation layer 13 is attached to the inner peripheral wall of the first semi-annular insulation box 12. When the insulation device is in the closed state, the first semi-annular insulation layer 13 is in contact with the packing gland C of the molten salt valve. The first semi-annular insulation layer 13 is fixed to the first semi-annular insulation box 12 by a detachable method such as self-tapping screws. That is, "fixed" here does not limit whether it is detachable, but rather limits the relative movement of the first semi-annular insulation layer 13 and the first semi-annular insulation box 12 when in use. Of course, other methods such as adhesive or snap-fit ​​can also be used.

[0039] Furthermore, a third semi-annular insulation layer 14, with a matching shape, is fixed to the inner wall of the first semi-annular shell 11, and the third semi-annular insulation layer 14 is adjacent to the upper part of the first semi-annular insulation box 12. Specifically, the top of the first semi-annular shell 11 abuts against the valve actuator A, but there may be a certain gap at the abutment, which is not conducive to the insulation effect of the device. Therefore, the third semi-annular insulation layer 14 is set to contact the bottom of the valve actuator A, so as to both insulate and seal the gap, preventing heat exchange between the outside air and the inside air, forming a closed space. The third semi-annular insulation layer 14 is fixed to the first semi-annular shell 11 by a detachable method such as self-tapping screws. That is, "fixed" here does not limit whether it is detachable, but limits that the third semi-annular insulation layer 14 and the first semi-annular shell 11 do not move relative to each other when in use. Of course, other methods such as adhesive or snap-fit ​​can also be used.

[0040] Continue to refer to Figure 1 and Figure 2 In this embodiment, the second semi-annular insulation body 2 includes a second semi-annular shell 21 and a second semi-annular insulation box 22 adapted to its shape. The second semi-annular insulation box 22 is located inside the second semi-annular shell 21, and the outer wall of the second semi-annular insulation box 22 is attached to the inner wall of the second semi-annular shell 21. The height of the second semi-annular insulation box 22 is lower than the height of the second semi-annular shell 21. The second semi-annular insulation box 22 has a removable lid to open or close the box cavity, which is filled with insulation material. Long-term use of the insulation material may lead to a decrease in insulation effect. The removable lid facilitates the inspection of the insulation material's condition. If the material performance deteriorates, the lid can be removed to replace the insulation material in the box, ensuring that the insulation device has good insulation performance.

[0041] More specifically, the second semi-annular shell 21 and the second semi-annular insulation box 22 can be made of metal, such as stainless steel and aluminum alloy. The first semi-annular shell 11 and the first semi-annular insulation box 12 can be fixed by nailing, welding or other methods, but are not limited to metal materials. Other materials that can withstand high temperatures and have sufficient mechanical strength can also be used as substitutes, such as high-temperature ceramics and composite materials, and fixed in an appropriate manner. The insulation material filled in the insulation box can be insulation cotton, such as aluminum silicate cotton, heat-insulating glass wool and heat-insulating pearl cotton, but is not limited to insulation cotton. Other materials that can play a heat-insulating role for molten salt can be used as substitutes.

[0042] Furthermore, a shape-fitting second semi-annular insulation layer 23 is fixed to the lower part of the inner peripheral wall of the second semi-annular insulation box 22, and the outer peripheral wall of the second semi-annular insulation layer 23 is attached to the inner peripheral wall of the second semi-annular insulation box 22. When the insulation device is in the closed state, the second semi-annular insulation layer 23 is in contact with the packing gland C of the molten salt valve. The second semi-annular insulation layer 23 is fixed to the second semi-annular insulation box 22 by a detachable method such as self-tapping screws. That is, "fixed" here does not limit whether it is detachable, but rather limits the relative movement of the second semi-annular insulation layer 23 and the second semi-annular insulation box 22 when in use. Of course, other methods such as adhesive or snap-fit ​​can also be used.

[0043] Furthermore, a fourth semi-annular insulation layer 24, with a matching shape, is fixed to the inner wall of the second semi-annular shell 21, and the fourth semi-annular insulation layer 24 is adjacent to the upper part of the second semi-annular insulation box 22. Specifically, the top of the second semi-annular shell 21 abuts against the valve actuator A, but there may be a certain gap at the abutment, which is not conducive to the insulation effect of the device. Therefore, the fourth semi-annular insulation layer 24 is set to contact the bottom of the valve actuator A, so as to both insulate and seal the gap, preventing heat exchange between the outside air and the inside air, forming a closed space. The fourth semi-annular insulation layer 24 is fixed to the second semi-annular shell 21 by a detachable method such as self-tapping screws. That is, "fixed" here does not limit whether it is detachable, but limits that the fourth semi-annular insulation layer 24 and the second semi-annular shell 21 do not move relative to each other when in use. Of course, other methods such as adhesive or snap-fit ​​can also be used.

[0044] One end of the first semi-annular shell 11 of the first semi-annular insulation body 1 and one end of the second semi-annular shell 21 of the second semi-annular insulation body 2 are hinged. Specifically, in this embodiment, the hinge is implemented using a hinge. One metal piece of the hinge is fixed to one end of the first semi-annular shell 11 and the other metal piece is fixed to one end of the second semi-annular shell 21. The two metal pieces are connected by a shaft or pin, allowing the two parts to rotate relative to each other while maintaining their fixed relationship.

[0045] The first connector is attached to the end of the outer wall of the first semi-annular housing 11 away from the hinge, and the second connector is attached to the end of the outer wall of the second semi-annular housing 21 away from the hinge. Specifically, the first connector is a latch 3, and the second connector is a self-tapping screw 4 that can overlap with the latch 3. The first and second connectors are detachably connected. When the first and second connectors are connected, the first semi-annular insulation body 1 and the second semi-annular insulation body 2 are locked, and the insulation device is in the closed state. When the first and second connectors are disconnected, the first semi-annular insulation body 1 and the second semi-annular insulation body 2 are unlocked, and the insulation device is in the open state. The first semi-annular insulation body 1 and the second semi-annular insulation body 2 can rotate around the hinge, thereby allowing the insulation device to switch between the open and closed states. Alternatively, the first and second connectors can be directly purchased as pre-made latches and fixed to the ends of the outer walls of the first semi-annular housing 11 and the second semi-annular housing 21 away from the hinge, respectively.

[0046] Specifically, when the insulation device is in the open state, the first connector and the second connector are separated. The operator can rotate the first semi-annular insulation body 1 and the second semi-annular insulation body 2 around the hinge to a suitable angle to open an appropriate opening for observing the freezing blockage of the molten salt in the packing gland C of the molten salt valve. The operator can also clean up the molten salt overflowing from the packing gland C. Thus, the operator can promptly identify problems and make judgments on whether further maintenance or repair is needed.

[0047] When the insulation device is in the closed state, the top and bottom ends of the first semi-annular shell 11 and the top and bottom ends of the second semi-annular shell 21 abut against the valve actuator A and the valve insulation tank B, respectively; the third semi-annular insulation layer 14 and the fourth semi-annular insulation layer 24 abut against the valve actuator A, and the first semi-annular insulation box 12 and the second semi-annular insulation box 22 can face the area between the valve actuator A and the valve insulation tank B. The first semi-annular insulation body 1 and the second semi-annular insulation body 2 are connected together to form a closed annular insulation space, which helps to maintain the temperature of the molten salt valve body and valve stem, avoids molten salt solidification, freezing blockage or other malfunctions due to excessively low temperature, and thus avoids obstruction of molten salt flow and blockage of valve switches by solidified molten salt, ensuring the stable operation of the molten salt system.

[0048] Specifically, molten salt is prone to leaking from the gap between the pressure cap and the valve stem during flow. Since the freezing point of molten salt is around 220℃, the leaked molten salt solidifies and crystallizes, blocking the gap between the pressure cap and the valve stem. This increases the resistance to valve stem movement, affecting the valve's normal movement and its control over the molten salt flow rate. Especially when the valve actuator A makes small adjustments to the valve stem, it cannot precisely adjust according to the instructions. Therefore, the area closest to the insulation box (i.e., the lower part of the inner circumferential wall of the first semi-annular insulation box 12) of the packing gland C provides better insulation for the molten salt valve. Furthermore, the top of the valve insulation tank B has a certain arc-shaped protrusion. There may be a gap at the contact point between the bottom of the insulation device and the top of the valve insulation tank B. The first semi-annular insulation layer 13 can also provide a certain degree of sealing at this contact point, thus forming a closed space.

[0049] Furthermore, a compressible seal 5 is provided on at least one of the adjacent end walls of the first semi-annular insulation box 12 and the second semi-annular insulation box 22 at the hinge (shown in the figure as being provided on the first semi-annular insulation box 12); a compressible seal 5 is also provided on at least one of the adjacent end walls of the first semi-annular insulation box 12 and the second semi-annular insulation box 22 at the locking position (also shown in the figure as being provided on the first semi-annular insulation box 12). The compressible seal 5 is made of insulation material. When the insulation device is in the closed state, the adjacent end walls of the first semi-annular insulation box 12 and the second semi-annular insulation box 22 clamp the compressible seal 5. Specifically, when the first semi-annular insulation body 1 and the second semi-annular insulation body 2 form a ring structure, there is a certain gap at the connection of the two ends, which will cause heat exchange between the outside air and the air inside the device, which is not conducive to the insulation effect of the device. The compressible seal 5 reduces the gap as much as possible by squeezing itself, thus maintaining the temperature of the internal area of ​​the ring structure. The compressible seal 5 is fixed to the first semi-annular insulation box 12 / second semi-annular insulation box 22 by a detachable method such as self-tapping screws. That is, "fixed" here does not limit whether it is detachable, but rather limits that the compressible seal 5 and the first semi-annular insulation box 12 / second semi-annular insulation box 22 do not move relative to each other when in use. Of course, other methods such as adhesive or snap-fit ​​can also be used.

[0050] Furthermore, when the insulation device is in the closed state, the end of the first semi-annular shell 11 away from the hinge overlaps the outer wall of the second semi-annular shell 21, and the width of the overlap area is greater than or equal to 10 mm, so as to further prevent heat loss through gaps.

[0051] The materials of the above compressible sealing element 5, the first semi-annular insulation layer 13, the second semi-annular insulation layer 23, the third semi-annular insulation layer 14, and the fourth semi-annular insulation layer 24 are selected from one of aerogel, aluminum silicate, ceramic fiber, and high silica cloth.

[0052] Example 2:

[0053] Based on Example 1, while maintaining the main structure and function of the molten salt valve insulation device in Example 1, this example introduces magnetic connectors to replace the original mechanical latches and self-tapping screw locking mechanisms.

[0054] A permanent magnet is embedded in the area of ​​the outer wall of the first semi-annular shell 11 away from the hinge and overlapping the outer wall of the second semi-annular shell 21, and a handle is fixedly installed on the outside. A magnetic metal sheet is embedded in the area of ​​the outer wall of the second semi-annular shell 21 away from the hinge and overlapping the outer wall of the first semi-annular shell 11. Specifically, the permanent magnet is a material capable of generating a persistent magnetic field, such as neodymium iron boron or samarium cobalt. The handle is an operating component for opening and closing the insulation device. By gripping the handle, the operator can easily pull the first semi-annular shell 11 toward or push the second semi-annular shell 21 to complete the opening and closing of the insulation device. The attractive force provided by the permanent magnet ensures a natural fit when closed, while the handle provides a convenient point of contact for applying force. The magnetic metal sheet is a thin sheet made of a material with high magnetic permeability, such as soft iron, nickel, or cobalt. It does not generate a magnetic field itself but can be attracted by the permanent magnet. The permanent magnet attracts the magnetic metal sheet to achieve a tight fit between the two. When the permanent magnet and the magnetic metal sheet are connected, the first semi-annular insulation body 1 and the second semi-annular insulation body 2 are locked, and the insulation device is in the closed state. When the connection between the first connector and the second connector is released, the first semi-annular insulation body 1 and the second semi-annular insulation body 2 are unlocked, and the insulation device is in the open state. The first semi-annular insulation body 1 and the second semi-annular insulation body 2 can rotate around the hinge, thereby enabling the insulation device to switch between the open and closed states.

[0055] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0056] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0057] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0058] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above 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 one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0059] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A heat preservation device for molten salt valves, characterized in that, The heat preservation device includes a first semi-annular heat preservation body (1) and a second semi-annular heat preservation body (2) that can be selectively locked, and the heat preservation device can switch between an open state and a closed state; When the first semi-annular insulation body (1) and the second semi-annular insulation body (2) are locked, the insulation device is in the closed state. The insulation device forms a ring structure that can cover the area between the valve actuator (A) and the valve insulation tank (B). Its upper end is connected to the bottom of the valve actuator (A) and its lower end is connected to the top of the valve insulation tank (B). When the first semi-annular insulation body (1) and the second semi-annular insulation body (2) are released from their locking, the insulation device is in the open state, and the insulation device can expose the area between the valve actuator (A) and the valve insulation tank (B), and can also be disassembled from the molten salt valve.

2. The heat preservation device for molten salt valves according to claim 1, characterized in that, The first semi-annular heat preservation body (1) and the second semi-annular heat preservation body (2) are hinged at one end, and the other end is provided with a first connector and a second connector respectively. The first connector and the second connector are detachably connected. By rotating the first semi-annular heat preservation body (1) and the second semi-annular heat preservation body (2) around the hinge, the heat preservation device can switch between the open state and the closed state. When the first semi-annular insulation body (1) and the second semi-annular insulation body (2) are connected by the first connector and the second connector, the insulation device is in the closed state; When the first connector and the second connector are separated, the first semi-annular insulation body (1) and the second semi-annular insulation body (2) rotate and open around their hinge, and the insulation device is in the open state.

3. The heat preservation device for molten salt valves as described in claim 2, characterized in that: The first semi-annular insulation body (1) includes a first semi-annular shell (11) and a first semi-annular insulation box (12) filled with insulation material. The first semi-annular insulation box (12) is attached and fixed to the inner side of the first semi-annular shell (11). The height of the first semi-annular insulation box (12) is lower than the height of the first semi-annular shell (11). The first connector is connected to the outer wall of the first semi-annular shell (11). The second semi-annular insulation body (2) includes a second semi-annular shell (21) and a second semi-annular insulation box (22) filled with insulation material. The second semi-annular insulation box (22) is attached and fixed to the inner side of the second semi-annular shell (21). The height of the second semi-annular insulation box (22) is lower than the height of the second semi-annular shell (21). The second connector is connected to the outer wall of the second semi-annular shell. When the insulation device is in the closed state, the top and bottom ends of the first semi-annular shell (11) and the top and bottom ends of the second semi-annular shell (21) respectively abut against the valve actuator (A) and the valve insulation tank (B); the first semi-annular insulation box (12) and the second semi-annular insulation box (22) can face the area between the valve actuator (A) and the valve insulation tank (B).

4. The heat preservation device for molten salt valves as described in claim 3, characterized in that: The first semi-annular heat preservation box (12) and the second semi-annular heat preservation box (22) have removable lids to open or close the box cavity of the first semi-annular heat preservation box (12) and the second semi-annular heat preservation box (22) used to fill the heat preservation material.

5. The heat preservation device for molten salt valves as described in claim 3, characterized in that: At least one of the adjacent end walls of the first semi-annular heat preservation box (12) and the second semi-annular heat preservation box (22) is provided with a compressible seal (5). When the heat preservation device is in the closed state, the adjacent end walls of the first semi-annular heat preservation box (12) and the second semi-annular heat preservation box (22) clamp the compressible seal (5). The compressible seal (5) is made of thermal insulation material.

6. The heat preservation device for molten salt valves as described in claim 5, characterized in that: The lower part of the inner peripheral wall of the first semi-annular insulation box (12) is fixed with a first semi-annular insulation layer (13) that fits the shape, and the lower part of the inner peripheral wall of the second semi-annular insulation box (22) is fixed with a second semi-annular insulation layer (23) that fits the shape. When the insulation device is in the closed state, the first semi-annular insulation layer (13) and the second semi-annular insulation layer (23) are in contact with the packing gland (C) of the molten salt valve. The inner wall of the first semi-annular shell (11) is fixed with a third semi-annular heat insulation layer (14) that fits the shape, and the third semi-annular heat insulation layer (14) is adjacent to the top of the first semi-annular heat insulation box (12). The inner wall of the second semi-annular shell (21) is fixed with a fourth semi-annular heat insulation layer (24) that matches the shape, and the fourth semi-annular heat insulation layer (24) is adjacent to the top of the second semi-annular heat insulation box (22). When the insulation device is in the closed state, the third semi-annular insulation layer (14) and the fourth semi-annular insulation layer (24) are in contact with the bottom end of the valve actuator (A).

7. The heat preservation device for molten salt valves as described in claim 6, characterized in that: The first semi-annular shell (11) and the second semi-annular shell (21) are made of metal; The first semi-annular heat preservation box (12) and the second semi-annular heat preservation box (22) are made of metal and filled with heat preservation cotton. The materials of the compressible seal (5), the first semi-annular insulation layer (13), the second semi-annular insulation layer (23), the third semi-annular insulation layer (14), and the fourth semi-annular insulation layer (24) are selected from aerogel, aluminum silicate, ceramic fiber, and high silica cloth.

8. The heat preservation device for molten salt valves as described in claim 3, characterized in that: When the heat preservation device is in the closed state, the end of the first semi-annular shell (11) away from the hinge overlaps the outer wall of the second semi-annular shell (21), and the width of the overlap area is greater than or equal to 10 mm.

9. The heat preservation device for molten salt valves as described in claim 2, characterized in that: The first connector and the second connector are a buckle (3) and a self-tapping screw (4) that can overlap with the buckle (3), respectively.

10. The heat preservation device for a molten salt valve as described in any one of claims 1-9, characterized in that: The molten salt valve is a molten salt valve used in solar thermal power plants.

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