A shunt pressure relief device and molten salt pressure relief recovery system

Abstract

This invention discloses a pressure relief device and a molten salt pressure relief and recovery system. The pressure relief device is connected to a molten salt energy storage system and used to relieve pressure on several molten salt energy storage devices within the system. The device includes a diversion component and a diversion component. The diversion component includes a pressure relief pipe and a pressure relief inner cavity. The diversion component includes a pressure relief outer cavity, a steam exhaust pipe, and a salt inlet pipe. The pressure relief outer cavity is fitted outside the pressure relief inner cavity and is sealed to the steam exhaust pipe and the salt inlet pipe. A partition is installed inside the pressure relief inner cavity, which can move within the cavity and divide it into two chambers. Several through holes are provided on the side wall of the inner cavity for connecting to the outer cavity. This invention relieves pressure and dissipates energy from the high-pressure steam medium through the inner and outer pressure relief cavities, and separates the steam and molten salt. The molten salt is then discharged from the outer cavity through the steam exhaust pipe and the salt inlet pipe, completing the recovery process. The pressure relief process is highly safe, and the molten salt is completely recovered.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of molten salt energy storage heating, in particular to a shunt pressure relief device and a molten salt pressure relief and recovery system. BACKGROUND

[0002] In the energy storage system of a solar power plant or a thermal power plant, steam-molten salt heat exchangers are used for heat storage and heat release.

[0003] If the pipeline valve on the molten salt side of the steam-molten salt heat exchanger is closed or the temperature of the molten salt is too low, the molten salt at the inlet and outlet of the pipeline will be blocked. After the molten salt is heated on the steam side, the molten salt expands due to heating, which causes the pressure in the molten salt tube plate and the molten salt energy storage equipment to rise. If the pressure is too high, the molten salt tube plate or the shell of the molten salt energy storage equipment will be broken, causing molten salt leakage. Therefore, a pressure relief device needs to be installed in the molten salt energy storage equipment or its connecting pipeline. In the prior art, a molten salt rupture disc is usually used to relieve the pressure of the molten salt energy storage equipment. When the pressure in the molten salt energy storage equipment is too high, the rupture disc will break, discharging the high-pressure molten salt vapor mixture in the storage tank to release the pressure in the molten salt energy storage equipment. This pressure relief method forms an impact when the rupture disc breaks, which is not conducive to the recovery of the molten salt and has safety hazards. SUMMARY

[0004] The present application aims to solve one of the above-mentioned technical problems in the prior art to some extent. To this end, the present application provides a shunt pressure relief device and a molten salt pressure relief and recovery system, which can safely relieve pressure and complete molten salt recovery.

[0005] In a first aspect, to achieve the above-mentioned object, the present application provides a shunt pressure relief device, which is connected to a molten salt energy storage system and used for relieving pressure of a plurality of molten salt energy storage equipment of the molten salt energy storage system. The shunt pressure relief device comprises a flow guide assembly and a shunt assembly. The flow guide assembly comprises a pressure relief pipeline and a pressure relief inner cavity. The shunt assembly comprises a pressure relief outer cavity, a steam discharge pipe and a salt guide pipe.

[0006] The pressure relief pipeline is in sealed communication with the molten salt energy storage equipment and the pressure relief inner cavity, so as to guide the high-pressure molten salt vapor mixture in the molten salt energy storage equipment into the pressure relief inner cavity.

[0007] The pressure relief outer cavity is arranged outside the pressure relief inner cavity. The pressure relief outer cavity is sealingly connected with the steam discharge pipe and the salt guide pipe. The steam discharge pipe and the salt guide pipe are respectively connected to the upper and lower sides of the pressure relief outer cavity along the height direction.

[0008] The pressure relief inner cavity is provided with a partition plate, which can move within the pressure relief inner cavity and divide the pressure relief inner cavity into two chambers. The side wall of the pressure relief inner cavity is provided with several through holes for connecting the pressure relief outer cavity, so that the high-pressure molten salt steam mixture pushes the partition plate and enters the pressure relief outer cavity through the through holes, and is discharged from the pressure relief outer cavity through the exhaust pipe and the salt inlet pipe.

[0009] In this technical solution, the diversion and pressure relief device includes a diversion component and a flow diversion component. The diversion component transports the high-pressure molten salt steam mixture in the molten salt energy storage device to the pressure relief inner cavity. The high-pressure molten salt steam mixture forms high pressure in the pressure relief inner cavity and pushes the baffle to complete the first pressure relief. After the baffle moves, the high-pressure steam mixture communicates with the through hole and enters the pressure relief outer cavity through the through hole. When the high-pressure steam mixture passes through the through hole, due to the large resistance inside the through hole, the high-pressure molten salt steam mixture completes the second pressure relief, and the pressure of the high-pressure molten salt steam mixture is further reduced. Finally, it enters the pressure relief outer cavity. Because the volume and cross-section of the pressure relief outer cavity are larger than the through hole, the flow rate of the mixed medium is reduced again. When the flow rate and pressure of the mixed medium are reduced, the density difference between molten salt and steam increases, and the molten salt and steam separate under the action of gravity. The steam enters the exhaust pipe located above the pressure relief outer cavity, while the molten salt enters the salt inlet pipe located below the pressure relief outer cavity, completing the pressure reduction and energy dissipation of the high-pressure mixed medium and the vapor-liquid separation and recovery.

[0010] Preferably, the baffle divides the pressure relief cavity into a first chamber and a second chamber that are isolated from each other. The first chamber is directly connected to the pressure relief pipe. An elastic element that abuts against the baffle is provided in the second chamber. When the air pressure in the first chamber is higher than a preset value, the high-pressure molten salt steam mixture pushes the baffle to move, causing the elastic element to release pressure from the high-pressure molten salt steam mixture in the first chamber. By providing an elastic element in the second chamber on the right side of the baffle, the pressure energy and kinetic energy of the high-pressure molten salt steam mixture (high-pressure mixing medium) are converted into the potential energy of the elastic element, improving the energy dissipation efficiency of the high-pressure mixing medium. At the same time, the potential energy of the elastic element causes the baffle to reset when the pressure relief cavity is in a low-pressure state.

[0011] Preferably, when the air pressure in the first chamber is lower than a preset value, the elastic element is in a reset state, and the through hole connects to the second chamber. When the air pressure in the first chamber is higher than the preset value, the elastic element is in a compressed state, and the through hole connects to the first chamber, so that the high-pressure molten salt vapor mixture in the first chamber enters the pressure relief outer cavity through the through hole.

[0012] Preferably, a salt-draining pipe is provided between the salt-inlet pipe and the pressure-relief inner cavity. One end of the salt-draining pipe is connected to the first chamber of the pressure-relief inner cavity, and the other end is connected to the salt-inlet pipe, so that when the air pressure in the first chamber is lower than a preset value, the solid salt deposited in the first chamber can enter the salt-inlet pipe along the salt-draining pipe.

[0013] Preferably, the edge of the partition is provided with a roller, which rolls along the inner wall of the pressure relief cavity to move the partition within the pressure relief cavity.

[0014] Preferably, the elastic element is a compression spring.

[0015] Preferably, the pressure relief pipeline includes several pressure relief sub-pipes and a pressure relief main pipe. The pressure relief sub-pipes are used to connect the molten salt energy storage device and the pressure relief main pipe, and the pressure relief main pipe is connected to the pressure relief inner cavity.

[0016] Furthermore, to achieve the above objectives, this application also proposes a molten salt pressure relief and recovery system, including a brine tank and a diversion pressure relief device. The diversion pressure relief device is configured as described in any of the above technical solutions, and is located inside the brine tank, with the pressure relief pipe and the exhaust pipe extending out of the brine tank. The reasoning process for the beneficial effects of the molten salt pressure relief and recovery system provided in this application is similar to that of the aforementioned diversion pressure relief device, and will not be repeated here.

[0017] Preferably, the salt-absorbing tank is configured as an atmospheric pressure tank in communication with air, the bottom of the salt-absorbing tank is provided with a molten salt layer, the salt inlet pipe is inserted into the molten salt layer, the bottom of the salt-absorbing tank is provided with a salt-absorbing trough, and the salt inlet pipe is inserted into the salt-absorbing trough.

[0018] Preferably, the salt-free tank is also equipped with a salt pump, which is used to transport molten salt so that the molten salt layer in the salt-free tank is maintained within a preset range.

[0019] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of the present invention will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of the present invention. In addition, each of these features, elements and components appearing in the following text and drawings is a plurality of, and different symbols or numbers are used for convenience of representation, but all represent parts with the same or similar construction or function. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings:

[0021] Figure 1 This is a schematic diagram of the diversion and pressure relief device in this embodiment;

[0022] Figure 2 This is a schematic diagram of the drainage component in this embodiment;

[0023] Figure 3 This is a schematic diagram of the structure of the current splitter component in this embodiment;

[0024] Figure 4 This is a schematic diagram of the diversion and pressure relief device and pressure relief pipeline structure in this embodiment;

[0025] Figure 5 This is a schematic diagram of the molten salt depressurization and recovery system in this embodiment.

[0026] Among them, 100 is the diversion assembly; 110 is the pressure relief pipe; 111 is the pressure relief sub-pipe; 112 is the pressure relief main pipe; 120 is the pressure relief inner cavity; 121 is the partition plate; 1211 is the roller; 122 is the through hole; 123 is the elastic element; 124 is the first chamber; 125 is the second chamber; 200 is the diversion assembly; 210 is the pressure relief outer cavity; 220 is the exhaust pipe; 230 is the salt inlet pipe; 240 is the salt draining pipe; 300 is the salt draining tank; 310 is the molten salt layer; 320 is the salt draining tank; and 330 is the salt pump. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain the present invention and should not be construed as limiting the invention.

[0028] The terms "an embodiment," "example," or "example" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this patent. The phrase "in some embodiments" appearing in various places in the specification does not necessarily refer to the same embodiment.

[0029] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0030] like Figures 1 to 4As shown, this embodiment provides a diversion and pressure relief device. The diversion and pressure relief device is connected to a molten salt energy storage system and is used to relieve pressure on several molten salt energy storage devices in the molten salt energy storage system. The molten salt energy storage devices include, but are not limited to, molten salt heat exchangers, molten salt electric heaters, and molten salt pump outlet pipes, etc. The diversion and pressure relief device includes a diversion component 100 and a diversion component 200. The diversion component 100 includes a pressure relief pipe 110 and a pressure relief inner cavity 120. The diversion component 200 includes a pressure relief outer cavity 210, a steam exhaust pipe 220, and a salt inlet pipe 230.

[0031] The pressure relief pipe 110 is sealed and connected to the molten salt energy storage device and the pressure relief inner cavity 120 to guide the high-pressure molten salt steam mixture (high-pressure mixing medium) in the molten salt energy storage device into the pressure relief inner cavity 120;

[0032] The pressure relief outer cavity 210 is sleeved on the outside of the pressure relief inner cavity 120. The pressure relief outer cavity 210 is sealed and connected to a steam exhaust pipe 220 and a salt inlet pipe 230. The steam exhaust pipe 220 and the salt inlet pipe 230 are respectively connected to the upper and lower sides of the pressure relief outer cavity 210 along the height direction.

[0033] A partition 121 is provided inside the pressure relief inner cavity 120. The partition 121 can move within the pressure relief inner cavity 120 and divide the pressure relief inner cavity 120 into two chambers. A plurality of through holes 122 for connecting the pressure relief outer cavity 210 are provided on the side wall of the pressure relief inner cavity 120, so that the high-pressure molten salt steam mixture pushes the partition 121 and enters the pressure relief outer cavity 210 through the through holes 122, and is discharged from the pressure relief outer cavity 210 through the exhaust pipe 220 and the salt inlet pipe 230.

[0034] In this technical solution, the diversion and pressure relief device includes a diversion component 100 and a diversion component 200. The diversion component 100 transports the high-pressure molten salt steam mixture in the molten salt energy storage device to the pressure relief inner cavity 120. The high-pressure molten salt steam mixture forms high pressure in the pressure relief inner cavity 120 and pushes the baffle 121 to complete one pressure relief. After the baffle 121 moves, the high-pressure steam mixture communicates with the through hole 122 and enters the pressure relief outer cavity 210 through the through hole 122. When the high-pressure steam mixture passes through the through hole 122, due to the large resistance inside the through hole 122, the high-pressure molten salt steam mixture... When the mixture passes through the through hole 122, it completes the second pressure relief, and the pressure of the high-pressure molten salt steam mixture is further reduced. Finally, it enters the pressure relief outer cavity 210. Because the volume and cross-section of the pressure relief outer cavity 210 are larger than those of the through hole 122, the flow rate of the mixed medium is reduced again. With the reduced flow rate and pressure of the mixed medium, the density difference between molten salt and steam increases, and the molten salt and steam separate under the action of gravity. The steam enters the exhaust pipe 220 located above the pressure relief outer cavity 210, while the molten salt enters the salt inlet pipe 230 located below the pressure relief outer cavity 210, thus completing the pressure reduction, energy dissipation, and vapor-liquid separation and recovery of the high-pressure mixed medium.

[0035] In some embodiments, such as Figure 1 , 2 As shown, the partition 121 divides the pressure relief cavity 120 into a first chamber 124 and a second chamber 125 that are isolated from each other. In this embodiment, the left side of the figure is the first chamber 124 and the right side of the figure is the second chamber 125. There is a small gap between the partition 121 and the side wall of the pressure relief cavity 120. The first chamber 124 is directly connected to the pressure relief pipe 110. The second chamber 125 is provided with an elastic element 123 that abuts against the partition 121. When the air pressure in the first chamber 124 is higher than a preset value (the molten salt energy storage device depressurizes, and the air pressure in the first chamber changes drastically), the high-pressure molten salt vapor mixture in the first chamber 124 pushes the partition 121 to move so that the elastic element 123 depressurizes the high-pressure molten salt vapor mixture in the first chamber 124. By providing an elastic element 123 in the second chamber 125 on the right side of the partition 121, the pressure energy of the high-pressure molten salt steam mixture (high-pressure mixing medium) is converted into the mechanical energy of the elastic element 123, thereby improving the energy dissipation efficiency of the high-pressure mixing medium. At the same time, the potential energy of the elastic element 123 causes the partition 121 to reset when the pressure relief inner cavity 120 is in a low-pressure state.

[0036] In some embodiments, such as Figure 1 , 2As shown, when the air pressure in the first chamber 124 is lower than a preset value, the elastic element 123 is in a reset state, and the preset air pressure is connected to the second chamber 125 via the through hole 122. When the air pressure in the first chamber 124 is higher than the preset value, the elastic element 123 is in a compressed state, and the through hole 122 is connected to the first chamber 124, so that the high-pressure molten salt vapor mixture in the first chamber 124 enters the pressure relief outer cavity 210 through the through hole 122. For example, the preset value is set to 2 to 10 times the standard atmospheric pressure. By setting the friction coefficient between the partition 121 and the pressure relief inner cavity 120 and the elastic coefficient of the elastic element 123, the partition 121 can only be moved a preset distance when the pressure exerted by the high-pressure mixed medium in the pressure relief inner cavity 120 on the partition 121 is greater than the preset pressure value. This causes the volume of the first chamber 124 to increase and the volume of the second chamber 125 to decrease. The through hole 122 is provided on the side wall of the second chamber 125 of the pressure relief inner cavity 120. After the partition 121 moves a preset distance, as the volume of the first chamber 124 increases, the through hole 122 connects to the first chamber 124, allowing the high-pressure molten salt vapor mixture in the first chamber 124 to enter the pressure relief outer cavity 210 through the through hole 122.

[0037] In some embodiments, such as Figure 1 , 3 As shown in Figure 4, a salt-draining pipe 240 is provided between the salt-inlet pipe 230 and the pressure-relief inner cavity 120. One end of the salt-draining pipe 240 is connected to the first chamber 124 of the pressure-relief inner cavity 120, and the other end is connected to the salt-inlet pipe 230, so that when the air pressure in the first chamber 124 is lower than a preset value, the molten salt mixture in the first chamber 124 can enter the salt-inlet pipe 230 along the salt-draining pipe 240. Specifically, the pressure relief inner cavity 120 is cylindrical, with a cap at its first end and the second end inserted into the pressure relief outer cavity 210. The first chamber 124 is located at the first end with the cap, and the upper and lower sides of the first end are respectively a pressure relief main pipe 112 and a salt-relief pipe 240. For example, the bottom end of the first chamber 124 is provided with a salt-relief pipe 240 interface. The salt-relief pipe 240 is sleeved on the salt-relief pipe 240 interface and is sealed and connected to the first chamber 124. When the pressure in the first chamber 124 is lower than a preset value, the partition 121 is in the initial position, and the first chamber 124 is not connected to the through hole 122. A small amount of solid salt deposits in the first chamber 124 (salt deposits formed after the molten salt remaining in the pipeline solidifies or salt deposits formed after the small amount of molten salt leaked during normal operation of the molten salt energy storage device solidifies) flow from the first chamber 124 into the salt inlet pipe 230 through the salt-relief pipe 240, and then are discharged to the outside of the diversion pressure relief device.

[0038] In some embodiments, the edge of the partition 121 is provided with a roller 1211, which rolls along the inner wall of the pressure relief cavity 120 to allow the partition 121 to move within the pressure relief cavity 120. By providing the roller 1211 at the edge of the partition 121, the coefficient of friction between the partition 121 and the inner wall of the pressure relief cavity 120 can be reduced, making the movement of the partition 121 within the pressure relief cavity 120 smoother.

[0039] Specifically, the elastic element 123 is configured as a compression spring, which dissipates energy from the high-pressure mixed medium within the pressure relief cavity 120. In other embodiments, the elastic element can also be configured as other components capable of providing energy dissipation for the molten salt. For example, the elastic element can be configured as two permanent magnets with the same magnetic poles. One of the two permanent magnets is disposed on the right side wall of the partition 121, and the other is disposed on the right side wall of the second chamber 125. The two permanent magnets with the same poles generate a repulsive force, and the magnitude of the repulsive force is inversely proportional to the specific value of the two permanent magnets. The greater the pressure formed by the high-pressure mixed medium in the first chamber, the farther the partition 121 is moved, and the greater the elastic force provided by the elastic element.

[0040] In some embodiments, such as Figure 4 As shown, the pressure relief pipe 110 includes several pressure relief sub-pipes 111 and a pressure relief main pipe 112. The pressure relief sub-pipes 111 are used to connect the molten salt energy storage device and the pressure relief main pipe 112, and the pressure relief main pipe 112 is connected to the pressure relief inner cavity 120. The diversion pressure relief device of this embodiment can be used to relieve pressure on multiple molten salt energy storage devices. The several pressure relief sub-pipes 111 are connected to several molten salt energy storage devices in a one-to-one correspondence. When the pressure of any one of the molten salt energy storage devices is too high, the high-pressure molten salt vapor mixture can be introduced into the pressure relief main pipe 112 through the pressure relief sub-pipe 111 connected to it, and then enter the diversion pressure relief device for diversion pressure relief.

[0041] like Figure 5 As shown, this embodiment also proposes a molten salt depressurization and recovery system, including a salt-recovery tank 300 and a diversion depressurization device. The diversion depressurization device is the same as described in any of the above embodiments. The diversion depressurization device is located inside the salt-recovery tank 300, and the depressurization pipe 110 and the exhaust pipe 220 extend out of the salt-recovery tank 300. The diversion depressurization device depressurizes and diverts the high-pressure molten salt steam mixture entering the device to obtain liquid molten salt flowing out of the salt inlet pipe 230 and steam flowing out of the exhaust pipe 220. The liquid molten salt flows into the salt-recovery tank 300 through the salt inlet pipe 230 for molten salt recovery, while the steam is discharged from the salt-recovery tank 300 through the exhaust pipe 220.

[0042] In some embodiments, such as Figure 5As shown, the salt-absorbing vessel 300 is configured as an atmospheric pressure vessel connected to air. A molten salt layer is provided at the bottom of the salt-absorbing vessel 300, and the salt inlet pipe 230 is inserted into the molten salt layer. A salt-absorbing trough 320 is provided at the bottom of the salt-absorbing vessel 300, and the salt inlet pipe 230 is inserted into the salt-absorbing trough 320. A certain amount of molten salt is provided at the bottom of the salt-absorbing vessel 300. This molten salt is used to maintain a certain temperature in the molten salt in the salt-absorbing trough 320, preventing the molten salt flowing out of the salt inlet pipe 230 from condensing in the salt-absorbing trough 320. Furthermore, the liquid molten salt in the salt-absorbing trough 320 prevents steam from entering the molten salt layer. When steam enters the molten salt layer, it creates a pressure difference between the inside and outside of the salt inlet pipe 230, generating pressure resistance, thus preventing steam from entering the bottom of the salt-absorbing trough 320.

[0043] In some embodiments, such as Figure 5 As shown, the salt-absorbing tank 300 is also equipped with a salt pump 330, which is used to transport molten salt to maintain the molten salt layer 310 within the salt-absorbing tank 300 within a preset range. The salt pump 330 transports molten salt into or out of the salt-absorbing tank 300, maintaining the molten salt level within the salt-absorbing tank 300 within a certain range and maintaining the temperature within the salt-absorbing tank 300 within a certain range.

[0044] In this embodiment of the molten salt pressure relief and recovery system, when an accident occurs in the molten salt heat exchanger, such as a ruptured heat exchanger tube or a broken end plate tube, the high-pressure steam from the molten salt heat exchanger will enter the low-pressure molten salt side, causing the pressure in the molten salt system to rise linearly. This triggers the pressure relief device (rupture disc, molten salt safety valve) to activate. The high-pressure molten salt steam mixture passes through the pressure relief device, then through the pressure relief sub-pipe 111 and the pressure relief main pipe 112 before entering the diversion pressure relief device. After entering the diversion pressure relief device, the high-pressure mixed medium, due to the small diameter of the salt-relief pipe 240 (e.g., an inner diameter of 5-8 mm) and its connection to the liquid molten salt layer, experiences high fluid resistance. Therefore, the high-pressure mixed medium will push the baffle 121 to move (towards...). Figure 1As shown on the right side), the elastic element 123 on the right side of the partition 121 is compressed, so that the through hole 122 on the right side of the pressure relief inner cavity 120 is connected to the first chamber 124, so that the high pressure mixed medium enters the pressure relief outer cavity 210 through the through hole 122. During the process of the high pressure mixed medium pushing the partition 121 to move and flowing into the pressure relief outer cavity 210 through the through hole 122, the kinetic energy and internal energy of the high pressure mixed medium are converted into the potential energy of the spring, and the pressure energy and kinetic energy of the high pressure mixed medium are reduced. During the compression of the spring, the potential and kinetic energy of the high-pressure mixed medium gradually decrease, while the mechanical energy generated by the spring compression gradually increases, eventually reaching equilibrium. After the mixed medium is depressurized by the spring, it passes through the through hole 122 of the depressurization inner cavity 120. When the high-pressure steam mixture passes through the through hole 122, due to the large resistance inside the through hole 122, the high-pressure molten salt steam mixture completes a second depressurization, further reducing the pressure of the high-pressure molten salt steam mixture. Finally, it enters the depressurization outer cavity 210. Because the volume and cross-section of the depressurization outer cavity 210 are larger than those of the through hole 122, the flow rate of the mixed medium decreases again. Under the condition of reduced flow rate and pressure of the mixed medium, due to the 50-200 times difference between the density of molten salt and the density of steam, the molten salt and steam separate under the action of gravity. The steam enters the upper half of the depressurization outer cavity 210 and then enters the exhaust pipe 220, and is finally led to the outside of the salt-removing tank 300 for discharge. Under the influence of gravity, the molten salt enters the salt inlet pipe 230 and then enters the lower molten salt layer of the salt drainage tank 320. This completes the energy dissipation and vapor-liquid separation and recovery of the high-pressure mixed medium.

[0045] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A pressure relief device, wherein a pipeline is connected to a molten salt energy storage system and is used to relieve pressure on several molten salt energy storage devices within the molten salt energy storage system, characterized in that, The diversion and pressure relief device includes a diversion assembly (100) and a diversion assembly (200). The diversion assembly (100) includes a pressure relief pipe (110) and a pressure relief inner cavity (120). The diversion assembly (200) includes a pressure relief outer cavity (210), a steam exhaust pipe (220), and a salt inlet pipe (230). The pressure relief pipe (110) is sealed and connected to the molten salt energy storage device and the pressure relief inner cavity (120) to guide the high-pressure molten salt steam mixture in the molten salt energy storage device into the pressure relief inner cavity (120); The pressure relief outer cavity (210) is sleeved on the outside of the pressure relief inner cavity (120). The pressure relief outer cavity (210) is sealed and connected to a steam exhaust pipe (220) and a salt inlet pipe (230). The steam exhaust pipe (220) and the salt inlet pipe (230) are respectively connected to the upper and lower sides of the pressure relief outer cavity (210) along the height direction. A partition (121) is provided inside the pressure relief inner cavity (120). The partition (121) can move inside the pressure relief inner cavity (120) and divide the pressure relief inner cavity (120) into two chambers. A plurality of through holes (122) are provided on the side wall of the pressure relief inner cavity (120) for connecting the pressure relief outer cavity (210) so that the high-pressure molten salt steam mixture pushes the partition (121) and enters the pressure relief outer cavity (210) along the through holes (122), and is discharged from the pressure relief outer cavity (210) through the exhaust pipe (220) and the salt inlet pipe (230).

2. The diversion and pressure relief device according to claim 1, characterized in that, The partition (121) divides the pressure relief cavity (120) into a first chamber (124) and a second chamber (125) that are isolated from each other. The first chamber (124) is directly connected to the pressure relief pipe (110). The second chamber (125) is provided with an elastic element (123) that abuts against the partition (121). When the air pressure in the first chamber (124) is higher than a preset value, the high-pressure molten salt vapor mixture pushes the partition (121) to move so that the elastic element (123) relieves the pressure of the high-pressure molten salt vapor mixture in the first chamber (124).

3. The diversion and pressure relief device according to claim 2, characterized in that, When the air pressure in the first chamber (124) is lower than a preset value, the elastic element (123) is in a reset state, and the through hole (122) is connected to the second chamber (125). When the air pressure in the first chamber (124) is higher than a preset value, the elastic element (123) is in a compressed state, and the through hole (122) is connected to the first chamber (124), so that the high-pressure molten salt vapor mixture in the first chamber (124) enters the pressure relief outer cavity (210) through the through hole (122).

4. The diversion and pressure relief device according to claim 2, characterized in that, A salt-draining pipe (240) is provided between the salt-inlet pipe (230) and the pressure-relief inner cavity (120). One end of the salt-draining pipe (240) is connected to the first chamber (124) of the pressure-relief inner cavity (120), and the other end is connected to the salt-inlet pipe (230). This allows solid salt deposits in the first chamber (124) to enter the salt-inlet pipe (230) along the salt-draining pipe (240) when the air pressure in the first chamber (124) is lower than a preset value.

5. The diversion and pressure relief device according to claim 2, characterized in that, The edge of the partition (121) is provided with a roller (1211), which rolls along the inner wall of the pressure relief cavity (120) to move the partition (121) within the pressure relief cavity (120).

6. The diversion and pressure relief device according to any one of claims 2 to 5, characterized in that, The elastic element (123) is configured as a compression spring.

7. The diversion and pressure relief device according to any one of claims 1 to 5, characterized in that, The pressure relief pipe (110) includes several pressure relief sub-pipes (111) and a pressure relief main pipe (112). The pressure relief sub-pipes (111) are used to connect the molten salt energy storage device and the pressure relief main pipe (112). The pressure relief main pipe (112) is connected to the pressure relief inner cavity (120).

8. A molten salt depressurization and recovery system, comprising a brine tank (300) and a diversion depressurization device, characterized in that, The pressure relief device is configured as described in any one of claims 1 to 7, wherein the pressure relief device is located inside the brine tank (300), and the pressure relief pipe (110) and the exhaust pipe (220) extend out of the brine tank (300).

9. The molten salt depressurization and recovery system according to claim 8, characterized in that, The salt-removing tank (300) is configured as an atmospheric pressure tank connected to air. A molten salt layer (310) is provided at the bottom of the salt-removing tank (300), and the salt inlet pipe (230) is inserted into the molten salt layer (310). A salt-removing trough (320) is provided at the bottom of the salt-removing tank (300), and the salt inlet pipe (230) is inserted into the salt-removing trough (320).

10. The molten salt depressurization and recovery system according to claim 8, characterized in that, The salt-absorbing tank (300) is also equipped with a salt pump, which is used to transport molten salt so that the molten salt layer (310) in the salt-absorbing tank (300) is maintained within a preset range.

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