Pressure protection device and energy storage device for energy storage

Abstract

The present invention proposes a pressure protection device and an energy storage device for energy storage. The pressure protection device for energy storage of the present invention comprises: a shell, the shell has a first cavity and a second cavity, and the first cavity and the second cavity both contain pressure protection liquid; an air inlet pipe, the air inlet pipe is arranged on the shell; an air pipe, the lower opening of the air pipe is located below the liquid level of the pressure protection liquid in the first cavity, and the distance between the lower opening of the air pipe and the liquid level of the pressure protection liquid in the first cavity in the vertical direction is a first preset value; an air outlet pipe, the air outlet pipe is arranged on the shell, and the inlet of the air outlet pipe is connected to the upper space of the pressure protection liquid in the second cavity; a pressure reducing pipe, at least part of the pressure reducing pipe is arranged in the second cavity, and the distance between the lower opening of the pressure reducing pipe and the liquid level of the pressure protection liquid in the second cavity in the vertical direction is a second preset value. Therefore, the pressure protection device for energy storage according to the present invention has the advantage of being able to perform negative pressure and overpressure protection.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and in particular to a pressure protection device and an energy storage device for energy storage. Background Art

[0002] In energy storage technologies, in addition to pumped storage, liquid flow battery storage, molten salt storage, and compressed air storage are gaining more and more attention from the industry due to their long duration, large capacity, small footprint, and no geographical restrictions. More and more 100-megawatt energy storage power stations with related technologies have been built, showing an explosive form. However, most of the above energy storage technologies use pressure vessels or there is a possibility of overpressure or negative pressure in the container during use due to gas increase and decrease, temperature rise and fall, etc., and most of the above technical routes use safety valves, bursting discs or breathing valves to solve this risk factor. Once the safety valve or bursting disc releases, it needs to be replaced or removed and recalibrated to set the pressure. Therefore, multiple sets of valves are needed for backup or temporary shutdown. The use of breathing valves cannot isolate the system from the atmospheric environment, and the gas in the container may leak into the atmosphere. Safety valves or bursting discs can only prevent safety accidents caused by the pressure in the container exceeding the design pressure, but cannot prevent safety accidents caused by "deflation" due to negative pressure in the container. Therefore, if there is the possibility of both overpressure and negative pressure, two sets of valves must be set at the same time to eliminate risks. In addition, safety valves and bursting discs are special equipment and need to be inspected by relevant government departments. These increase operating costs and system construction costs. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides a pressure protection device and an energy storage device for energy storage.

[0004] The pressure protection device for energy storage according to the embodiment of the present invention comprises:

[0005] A shell, the shell having a first cavity and a second cavity, wherein the first cavity and the second cavity both contain a pressure protection liquid;

[0006] An air inlet pipe, wherein the air inlet pipe is arranged on the shell, the inlet of the air inlet pipe is used to communicate with the gas phase space of the protected device, the outlet of the air inlet pipe is communicated with the first cavity, the outlet of the air inlet pipe is located above the pressure protection liquid in the first cavity, and the gas in the gas phase space of the protected device can pass into the space above the pressure protection liquid in the first cavity;

[0007] An air pipe, wherein the upper opening of the air pipe is located outside the shell, the lower opening of the air pipe extends downward into the first cavity, the lower opening of the air pipe is located below the liquid level of the pressure protection liquid in the first cavity, and the distance between the lower opening of the air pipe and the liquid level of the pressure protection liquid in the first cavity in the vertical direction is a first preset value;

[0008] An air outlet pipe, the air outlet pipe is arranged on the shell, and the inlet of the air outlet pipe is connected to the upper space of the pressure protection liquid in the second cavity;

[0009] A pressure-reducing pipe, at least part of which is arranged in the second cavity, the upper opening of the pressure-reducing pipe is connected to the air inlet pipe, the gas in the gas phase space of the protected equipment can pass into the pressure-reducing pipe, the lower opening of the pressure-reducing pipe is located below the liquid level of the pressure protection liquid in the second cavity, and the distance between the lower opening of the pressure-reducing pipe and the liquid level of the pressure protection liquid in the second cavity in the upper and lower directions is a second preset value.

[0010] Therefore, the pressure protection device for energy storage according to the embodiment of the present invention has the advantage of being able to perform negative pressure and overpressure protection.

[0011] In some embodiments, a partition is provided in the shell, and the thickness direction of the partition is the up and down direction. The partition divides the cavity of the shell into the first cavity and the second cavity. The upper opening of the pressure-reducing tube is located in the first cavity, and the upper opening of the pressure-reducing tube is located above the lower opening of the air pipe. The distance between the lower opening of the air pipe and the upper opening of the pressure-reducing tube in the up and down direction is the first preset value.

[0012] In some embodiments, the upper opening of the air tube is connected to the atmosphere or the protective gas inlet, and the air pressure of the upper opening of the air tube is the atmospheric pressure;

[0013] The shell is provided with a liquid inlet pipe, and the outlet of the liquid inlet pipe is connected with the first cavity;

[0014] The shell is provided with a drain pipe, and the inlet of the drain pipe is communicated with the second cavity.

[0015] In some embodiments, a first baffle is provided in the second cavity, the thickness direction of the first baffle is horizontal, the lower edge and the edge in the horizontal direction of the first baffle are connected to the wall of the second cavity, the upper edge of the first baffle is spaced apart from the second cavity, the first baffle divides the lower part or the lower middle part of the second cavity into a first sub-cavity and a second sub-cavity, the upper part of the first sub-cavity is connected to the upper part of the second sub-cavity, the pressure protection liquid in the second cavity is located in the first sub-cavity, the lower opening of the pressure reducing tube is located in the first sub-cavity, the lower opening of the pressure reducing tube is located below the upper edge of the first baffle, the distance between the lower opening of the pressure reducing tube and the upper edge of the first baffle is the second preset value, and the inlet of the drain pipe is connected to the second sub-cavity.

[0016] In some embodiments, the outer circumference of the liquid inlet pipe and the liquid outlet pipe are both provided with a heating device and a thermal insulation layer;

[0017] The shell is provided with a sight glass for observing the second cavity, and / or the drain pipe is provided with a sight glass.

[0018] In some embodiments, a support is provided at the bottom of the housing, and the housing is located above the protected device;

[0019] The outlet of the gas outlet pipe is connected to the gas processing equipment;

[0020] The shell is provided with a first sewage pipe, the first sewage pipe is connected with the bottom of the first cavity, and the first sewage pipe is provided with a first opening and closing valve;

[0021] The shell is provided with a second sewage pipe, the second sewage pipe is communicated with the bottom of the first sub-cavity, and the second sewage pipe is provided with a second opening and closing valve.

[0022] In some embodiments, a second baffle is provided in the first cavity, the thickness direction of the second baffle is horizontal, the lower edge and the edge in the horizontal direction of the second baffle are connected to the wall of the first cavity, the upper edge of the second baffle is spaced apart from the first cavity, the second baffle divides the lower part or the lower middle part of the first cavity into a third sub-cavity and a fourth sub-cavity, the upper part of the third sub-cavity is connected to the upper part of the fourth sub-cavity, the pressure protection liquid in the first cavity is located in the third sub-cavity, the lower opening of the air pipe is located in the third sub-cavity, the lower opening of the air pipe is located below the upper edge of the second baffle, and the distance between the lower opening of the air pipe and the upper edge of the second baffle is the first preset value.

[0023] In some embodiments, the pressure protection liquid includes at least one of a liquid phase energy storage medium, water, an aqueous solution, an organic liquid, and a molten liquid;

[0024] The relationship between the negative pressure safety value of the design air pressure of the protected equipment and the first preset value satisfies the first formula;

[0025] The first formula: P1=ρgh1, where P1 is the negative pressure safety value of the design air pressure of the protected equipment, ρ is the density of the pressure protection liquid, g is the acceleration of gravity, and h1 is the first preset value;

[0026] The positive pressure safety value of the design air pressure of the protected equipment and the second preset value satisfy the second formula;

[0027] The second formula: P2=ρgh2, where P2 is the positive pressure safety value of the design air pressure of the protected equipment, ρ is the density of the pressure protection liquid, g is the gravitational acceleration, and h2 is the second preset value.

[0028] The present invention also provides an energy storage device, comprising

[0029] Protected equipment;

[0030] A pressure protection device for energy storage, wherein the pressure protection device for energy storage is the above-mentioned pressure protection device for energy storage, and the gas phase space of the protected device is connected to the air inlet pipe of the pressure protection device for energy storage.

[0031] In some embodiments, the pressure protection device for energy storage is provided with a liquid return pipe, and the liquid return pipe is connected to the liquid inlet of the protected device;

[0032] There are multiple protected devices, the meteorological spaces of the multiple protected devices are connected in series in sequence, and the gas phase space of one of the multiple protected devices is connected to the air inlet pipe of the pressure protection device for energy storage through a pipeline;

[0033] Alternatively, there are multiple protected devices, and the gas phase space of each of the protected devices is connected to the air inlet pipe of the pressure protection device for energy storage through a pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of a pressure protection device for energy storage according to an embodiment of the present invention.

[0035] Figure 2 is a schematic diagram of an energy storage device according to an embodiment of the present invention.

[0036] Figure 3 is a schematic diagram of an energy storage device according to an embodiment of the present invention.

[0037] Figure numerals: 1. Shell, 11. First cavity, 12. Second cavity, 121. First sub-cavity, 122. Second sub-cavity, 2. Air inlet pipe, 3. Air outlet pipe, 4. Air pipe, 5. Pressure reducing pipe, 6. Partition, 7. Liquid inlet pipe, 8. Liquid discharge pipe, 9. First baffle, 10. Support, 11. First sewage pipe, 12. Second sewage pipe, 13. Protected equipment. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0039] The following describes the pressure protection device for energy storage according to an embodiment of the present invention with reference to the accompanying drawings. Figures 1 to 3 As shown, the pressure protection device for energy storage according to an embodiment of the present invention includes a housing 1 , an air inlet pipe 2 , an air pipe 4 , an air outlet pipe 3 and a pressure reducing pipe 5 .

[0040] The housing 1 has a first cavity 11 and a second cavity 12 , and pressure protection liquid is contained in both the first cavity 11 and the second cavity 12 .

[0041] The air inlet pipe 2 is arranged on the housing 1, and the inlet of the air inlet pipe 2 is used to communicate with the gas phase space of the protected device 13, and the outlet of the air inlet pipe 2 is communicated with the first cavity 11. The outlet of the air inlet pipe 2 is located above the pressure protection liquid in the first cavity 11, and the gas in the gas phase space of the protected device 13 can pass into the space above the pressure protection liquid in the first cavity 11. That is, the gas phase space of the protected device 13 is communicated with the space above the pressure protection liquid in the first cavity 11, so that the pressure of the gas phase space of the protected device 13 is equal to the pressure of the space above the pressure protection liquid in the first cavity 11.

[0042] The upper opening of the air pipe 4 is located outside the shell 1, and the lower opening of the air pipe 4 extends downward into the first cavity 11. The lower opening of the air pipe 4 is located below the liquid level of the pressure protection liquid in the first cavity 11, and the distance between the lower opening of the air pipe 4 and the liquid level of the pressure protection liquid in the first cavity 11 in the vertical direction is a first preset value. Specifically, the air inlet pipe 2 is provided at the top of the shell 1, and the outlet of the air inlet pipe 2 is located at the top of the first cavity 11. The air pipe 4 extends in the vertical direction, and the lower opening of the air pipe 4 is inserted downward from the top of the shell 1 into the first cavity 11. The vertical direction is shown by the arrows in the figure.

[0043] The pressure protection liquid of the first cavity 11 can separate the space above the pressure protection liquid of the first cavity 11 from the air space in the air pipe 4. When the pressure difference between the space above the pressure protection liquid of the first cavity 11 and the outside air is small, the gas in the first cavity 11 (so that the gas in the gas phase space of the protected device 13) cannot be connected with the outside. When the pressure of the first cavity 11 is low (that is, when the pressure in the protected device 13 is low, the gas pressure in the outside is much greater than the gas pressure in the protected device 13 and presses against the protected device 13), the air from the outside into the air pipe 4 can first pass downward through the pressure protection liquid at the outlet of the air pipe 4 and then enter the space above the pressure protection liquid of the first cavity 11 upward under the action of the pressure difference, so as to enter the gas phase space in the protected device 13. In this way, the safety accidents caused by the "deflation" of the gas phase space in the protected device 13 due to negative pressure can be reduced.

[0044] The air outlet pipe 3 is arranged on the housing 1, and the inlet of the air outlet pipe 3 is connected to the space above the pressure protection liquid in the second cavity 12. At least part of the pressure reducing pipe 5 is arranged in the second cavity 12. The upper opening of the pressure reducing pipe 5 is connected to the air inlet pipe 2, and the gas in the gas phase space of the protected equipment 13 can pass into the pressure reducing pipe 5. The lower opening of the pressure reducing pipe 5 is located below the liquid level of the pressure protection liquid in the second cavity 12, and the distance between the lower opening of the pressure reducing pipe 5 and the liquid level of the pressure protection liquid in the second cavity 12 in the vertical direction is a second preset value.

[0045] When the pressure difference between the space above the pressure protection liquid of the second cavity 12 and the outside air is small, the gas in the second cavity 12 (so that the gas in the gas phase space of the protected device 13) cannot communicate with the outside. When the pressure in the second cavity 12 is relatively high (i.e., when the pressure in the protected device 13 is relatively high, the pressure in the protected device 13 exceeds the set safety pressure), under the action of the air pressure difference, the gas in the second cavity 12 (the gas in the gas phase space of the protected device 13) first passes downward through the pressure protection liquid at the outlet of the pressure reducing pipe 5 and then enters the space above the pressure protection liquid of the second cavity 12 upward, thereby discharging the gas in the second cavity 12 (the gas in the gas phase space of the protected device 13) to the outside through the gas outlet pipe 3, thereby reducing the gas pressure in the gas phase space of the protected device 13, so as to reduce the safety accidents caused by the pressure in the gas phase space of the protected device 13 exceeding the design pressure.

[0046] The pressure protection device for energy storage according to the embodiment of the present invention is provided with an air pipe 4 connected to the first cavity 11 and the pressure protection liquid inserted into the first cavity 11, so that when the negative pressure in the protected device 13 is greatly different from the external pressure, the external air can pass through the partition of the pressure protection liquid in the first cavity 11, thereby reducing the safety accidents caused by negative pressure. And the distance between the lower opening of the air pipe 4 and the liquid surface of the pressure protection liquid in the first cavity 11 in the vertical direction is a first preset value, thus, by adjusting the value of the first preset value (i.e. adjusting the distance between the lower opening of the air pipe 4 and the liquid surface of the pressure protection liquid in the first cavity 11), the pressure in the first cavity 11 is about to reach (the pressure in the protected device 13) when the third preset pressure, the external air shell is passed into the first cavity 11 (inside the protected device 13), thereby forming negative pressure protection.

[0047] The pressure protection device for energy storage according to the embodiment of the present invention is provided with a second cavity 12, an air outlet pipe 3 and a pressure reducing pipe 5 inserted into the pressure protection liquid of the second cavity 12, so that when the protected device 13 forms an overpressure and has a large pressure difference with the outside, the gas in the second cavity 12 (the gas in the gas phase space of the protected device 13) first passes downward through the pressure protection liquid at the outlet of the pressure reducing pipe 5 and is discharged to the outside through the air outlet pipe 3, thereby reducing the gas pressure in the gas phase space of the protected device 13, so as to reduce the safety accidents caused by overpressure. And the distance between the lower opening of the pressure reducing pipe 5 and the liquid surface of the pressure protection liquid of the second cavity 12 in the vertical direction is a second preset value, thereby, by adjusting the value of the second preset value (i.e., the distance between the lower opening of the pressure reducing pipe 5 and the liquid surface of the pressure protection liquid of the second cavity 12), so that the pressure in the second cavity 12 increases to (the pressure in the protected device 13) at the fourth preset pressure, the gas in the second cavity 12 (in the protected device 13) can be discharged, thereby forming overpressure protection.

[0048] The pressure protection device for energy storage according to the embodiment of the present invention does not need to be replaced or recalibrated after releasing or replenishing the pressure, and can be used online continuously for multiple times, and the energy storage system will not be temporarily shut down for maintenance due to the calibration of the pressure protection device. It is a normal pressure device and not a special equipment, so it does not require regular annual inspections or the processing of special equipment documents, which saves annual inspection fees and procedure time, can reduce energy storage system investment, shorten construction periods, and reduce operating costs. The pressure protection device for energy storage according to the embodiment of the present invention can use the energy storage system's own energy storage medium (molten salt, electrolyte), etc. as the pressure protection liquid without the need for additional other consumption, and has low dependence on the environment. It can also use various types of liquids such as water and aqueous solutions. It is flexible in selection and can widely use a variety of energy storage technologies.

[0049] Therefore, the pressure protection device for energy storage according to the embodiment of the present invention has the advantage of being able to perform negative pressure and overpressure protection.

[0050] In some embodiments, a partition 6 is provided in the housing 1, and the thickness direction of the partition 6 is the vertical direction. The partition 6 divides the cavity of the housing 1 into a first cavity 11 and a second cavity 12, and the first cavity 11 is located above the second cavity 12. The upper opening of the pressure-reducing tube 5 is located in the first cavity 11, and the upper opening of the pressure-reducing tube 5 is located above the lower opening of the air pipe 4. The distance between the lower opening of the air pipe 4 and the upper opening of the pressure-reducing tube 5 in the vertical direction is a first preset value. Therefore, when the pressure protection liquid is injected into the first cavity 11, when the liquid level of the liquid in the first cavity 11 is flush with the upper opening of the pressure-reducing tube 5, it is the required liquid level of the pressure protection liquid. When the pressure protection liquid continues to be injected into the first cavity 11, the pressure protection liquid in the first cavity 11 can be discharged from the pressure reducing pipe 5 into the second cavity 12, so as to replenish the pressure protection liquid for the first cavity 11 and make the distance between the lower opening of the air tube 4 and the liquid level of the pressure protection liquid in the first cavity 11 in the vertical direction to be a first preset value.

[0051] like Figure 1 As shown, in some embodiments, a liquid inlet pipe 7 is provided on the housing 1, and an outlet of the liquid inlet pipe 7 is connected to the first cavity 11. Specifically, at least a portion of the liquid inlet pipe 7 is located above the pressure reducing pipe 5, so that the pressure protection liquid can be injected into the first cavity 11 through the liquid inlet pipe 7.

[0052] In some embodiments, a drain pipe 8 is provided on the housing 1, and an inlet of the drain pipe 8 is connected to the second cavity 12. The inlet of the drain pipe 8 is located at the lower part of the second cavity 12, so that the liquid in the second cavity 12 can be discharged from the drain pipe 8.

[0053] like Figure 1 As shown, in some embodiments, a first baffle 9 is provided in the second cavity 12 .

[0054] The thickness direction of the first baffle plate 9 is the horizontal direction, the lower edge and the edge in the horizontal direction of the first baffle plate 9 are connected to the wall surface of the second cavity 12, and the upper edge of the first baffle plate 9 is spaced apart from the second cavity 12. The first baffle plate 9 divides the lower part or the middle and lower part of the second cavity 12 into a first sub-cavity 121 and a second sub-cavity 122, and the upper part of the first sub-cavity 121 is connected to the upper part of the second sub-cavity 122. The pressure protection liquid in the second cavity 12 is located in the first sub-cavity 121, and the lower opening of the pressure reducing pipe 5 is located in the first sub-cavity 121. The lower opening of the pressure reducing pipe 5 is located below the upper edge of the first baffle plate 9, and the distance between the lower opening of the pressure reducing pipe 5 and the upper edge of the first baffle plate 9 is a second preset value, and the inlet of the drain pipe 8 is connected to the second sub-cavity 122. Thus, when the liquid inlet pipe 7 injects liquid into the first sub-cavity 121 through the first cavity 11 and the pressure-reducing pipe 5, when the liquid level in the first sub-cavity 121 is flush with the upper edge of the first baffle 9, the required liquid level of the pressure protection liquid is reached. When the liquid continues to be injected, the pressure protection liquid in the first sub-cavity 121 can flow into the second sub-cavity 122 and then be discharged from the liquid discharge pipe 8. For example, the thickness direction of the first baffle 9 is the left-right direction, and the left-right direction is shown by the arrow in the figure.

[0055] In some embodiments, the outer circumference of the liquid inlet pipe 7 and the liquid discharge pipe 8 are both provided with heating equipment and a thermal insulation layer. Specifically, the liquid inlet pipe 7 can be connected to the bypass of the liquid inlet pump or the system's own energy storage medium pump (such as an electrolyte pump, a molten salt pump, etc.). After the liquid is pressurized, the pressure protection liquid is injected into the first cavity 11 above the partition 6 through the liquid inlet pipe 7, and after overflowing the pressure-reducing pipe 5, it enters the first sub-cavity 121 below the partition 6 through the pressure-reducing pipe 5 and flows out through the liquid discharge pipe 8 after overflowing the first baffle 9. Heat can be provided and the thermal insulation layer can be coated by external heating of steam coils, jacket heating or electric heating. The liquid inlet pipe 7 and the liquid discharge pipe 8 are the inlet and outlet of the heating medium, respectively. It is required that the liquid inlet pipe 7 is arranged above the partition 6 and not lower than the upper opening of the pressure-reducing pipe 5, and the liquid discharge pipe 8 is arranged at the bottom of the inner second cavity 12.

[0056] In some embodiments, a sight glass for observing the second cavity 12 is provided on the housing 1, and / or a sight glass is provided on the drain pipe 8. For example, a sight glass for observing the second cavity 12 is provided on the housing 1, and the progress of the liquid replenishment of the pressure protection liquid can be observed through the sight glass of the second cavity 12, so that the condition of the pressure protection liquid in the second cavity 12 can be directly observed. The sight glass provided on the drain pipe 8 can also prove that the pressure protection liquid has been replenished when the drain pipe 8 is draining.

[0057] like Figure 1As shown, in some embodiments, a support 10 is provided at the bottom of the housing 1, and the housing 1 is located above the protected device 13. Specifically, the pressure protection device for energy storage can be installed on the top of the protected device 13 (such as an energy storage system) through the support 10, and is located at a high point. The gas phase space of the protection device 13 (such as an energy storage system) is connected to the flange of the air inlet pipe 2 through a pipeline; the atmospheric environment is connected to the flange of the air pipe 4 through a pipeline.

[0058] In some embodiments, the outlet of the gas outlet pipe 3 is connected to a gas processing device, so that the gas can be discharged after being processed to meet the emission standards.

[0059] like Figure 1 As shown, in some embodiments, a first drain pipe 11 is provided on the housing 1, the first drain pipe 11 is connected to the bottom of the first cavity 11, and a first opening and closing valve is provided on the first drain pipe 11. A second drain pipe 12 is provided on the housing 1, the second drain pipe 12 is connected to the bottom of the first sub-cavity 121, and a second opening and closing valve is provided on the second drain pipe 12. Therefore, during maintenance, the first drain pipe 11 can drain the liquid in the first cavity 11 above the partition 6, and the second drain pipe 12 can drain the liquid in the first sub-cavity 121 below the partition 6, and collect them uniformly through external pipelines.

[0060] In some embodiments, a second baffle is provided in the first cavity 11, and the thickness direction of the second baffle is horizontal. The lower edge and the edge in the horizontal direction of the second baffle are connected to the wall of the first cavity 11, and the upper edge of the second baffle is spaced apart from the first cavity 11. The second baffle divides the lower part or the lower middle part of the first cavity 11 into a third sub-cavity and a fourth sub-cavity, and the upper part of the third sub-cavity is connected to the upper part of the fourth sub-cavity. The pressure protection liquid in the first cavity 11 is located in the third sub-cavity, and the lower opening of the air tube 4 is located in the third sub-cavity. The lower opening of the air tube 4 is located below the upper edge of the second baffle, and the distance between the lower opening of the air tube 4 and the upper edge of the second baffle is a first preset value.

[0061] In some embodiments, the pressure protection liquid includes at least one of a liquid phase energy storage medium, water, an aqueous solution, an organic liquid, and a molten liquid. For example, the pressure protection liquid is the same as the liquid in the protected device 13. Specifically, the pressure protection device used for energy storage can be made of metal or non-metal material, which can be flexibly selected according to the energy storage medium, energy storage pressure, and application environment. For example, when applied to a flow battery energy storage system, corrosion-resistant non-metallic materials such as PPH and tetrafluoroethylene can be used; when applied to a compressed air or molten salt heat storage energy storage system, a metal material can be used. The pressure protection liquid used in the pressure protection device for energy storage, such as an electrolyte, a liquid molten salt, etc., is used as a pressure control liquid. The system's protection pressure value (constant pressure) is set by setting the liquid level of the control liquid inside the device. When the pressure of the energy storage system or equipment is higher or lower than the set pressure protection value, the pressure protection system can automatically remove the system pressure or inhale the atmospheric pressure to achieve safe discharge or supplementary pressure to protect the system and equipment.

[0062] like Figure 1 As shown, in some embodiments, the upper opening of the air tube 4 is connected to the atmosphere or the protective gas inlet, and the gas pressure of the upper opening of the air tube 4 is the atmospheric pressure.

[0063] In some embodiments, the relationship between the negative pressure safety value of the design air pressure of the protected device 13 and the first preset value satisfies the first formula. The first formula: P1 = ρgh1, where P1 is the negative pressure safety value of the design air pressure of the protected device 13, ρ is the density of the pressure protection liquid, g is the acceleration of gravity, and h1 is the first preset value. That is, P1 can be changed by changing the type (density) of the pressure protection liquid and the size of the first preset value. P1 is the minimum value of the negative pressure that the protected device 13 can withstand. When the pressure of the protected device 13 decreases due to factors such as temperature and liquid level reduction, and a negative pressure is formed and exceeds the static pressure of the h1 liquid surface (the negative pressure safety value of the design air pressure), that is, the air pressure in the protected device 13 is lower than the negative pressure safety value of the design air pressure, the atmosphere or protective gas instantly breaks the liquid seal from the h1 liquid surface and enters the protected device 13 through the air pipe 4, thereby replenishing the pressure of the closed system, avoiding deflation due to negative pressure, and thus protecting the equipment from damage or accidents caused by pressure reduction.

[0064] The positive pressure safety value of the design air pressure of the protected equipment 13 and the second preset value satisfy the second formula. The second formula: P2 = ρgh2, where P2 is the positive pressure safety value of the design air pressure of the protected equipment 13, ρ is the density of the pressure protection liquid, g is the acceleration of gravity, and h2 is the second preset value. That is, P2 can be changed by changing the type (density) of the pressure protection liquid and the size of the second preset value. P2 is the maximum value of the positive pressure that the protected equipment 13 can withstand. When the pressure of the protected equipment 13 rises and exceeds the static pressure formed by h2 (the positive pressure safety value of the design air pressure), a large amount of gas instantly escapes from the liquid surface at the first baffle 9 and is discharged into the atmosphere through the outlet pipe 3. Since a large amount of gas is instantly discharged from the closed system, equipment damage or accidents caused by continuous pressure increases are prevented.

[0065] Since a liquid energy storage medium (pressure protection liquid) is used to isolate the equipment and the energy storage system from the atmospheric environment, the air in the atmosphere does not directly enter the closed system (the protected equipment 13 and the first cavity 11 and the second cavity 12) during normal operation, thereby preventing the energy storage medium (such as molten salt or electrolyte, etc.) from oxidizing and deteriorating due to the entry of air, or affecting the safety and service life of the system.

[0066] The present invention also proposes an energy storage device, which includes a protected device 13 and a pressure protection device for energy storage according to an embodiment of the present invention. The gas phase space of the protected device 13 is connected to the air inlet pipe 2 of the pressure protection device for energy storage.

[0067] Therefore, the energy storage device according to the embodiment of the present invention has the advantage of being able to provide negative pressure and overpressure protection to the protected device 13 .

[0068] In some embodiments, a liquid return pipe is provided on the pressure protection device for energy storage, and the liquid return pipe is connected to the liquid inlet of the protected device 13. Specifically, the inlet of the liquid return pipe is connected to at least one of the first sewage pipe 11, the second sewage pipe 12 and the liquid discharge pipe 8. In this way, the liquid discharged from the pressure protection device for energy storage according to the embodiment of the present invention can be passed into the protected device 13 (after treatment) for recycling.

[0069] When pressure protection is performed on multiple protected devices 13, a series or parallel connection is adopted according to the arrangement or energy storage principle, thereby reducing investment and cost while achieving pressure protection.

[0070] like Figure 2As shown, in some embodiments, there are multiple protected devices 13, and the gas phase spaces of the multiple protected devices 13 are connected in series in sequence, and the gas phase space of one of the multiple protected devices 13 is connected to the air inlet pipe 2 of the pressure protection device for energy storage through a pipeline. For example, multiple protected devices 13 are connected in series with the gas phase space (first cavity 11 and second cavity 12) of the pressure protection device for energy storage through a pipeline, and the gas phase space of the last protected device 13 is connected to the air inlet pipe on the shell 1 through a pipeline, and the air outlet pipe 3 is vented to the gas treatment device or directly to the atmosphere through a pipeline. The air pipe 4 is directly connected to the atmospheric environment through a pipeline, and the liquid in the storage tank or energy storage system enters the first cavity 11 and the second cavity 12 through the liquid inlet pipe 7 after being pressurized by the pump. The first sewage pipe 11, the second sewage pipe 12 and the liquid discharge pipe 8 are connected to the pipeline and valves are set respectively, and can be combined into a main pipe to return to the protected device 13 by gravity.

[0071] like Figure 3 As shown, in some embodiments, there are multiple protected devices 13, and the gas phase space of each of the protected devices 13 is connected to the air inlet pipe 2 of the pressure protection device for energy storage through a pipeline.

[0072] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0073] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0074] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0076] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0077] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A pressure protection device for energy storage, characterized in that: include: A shell, the shell having a first cavity and a second cavity, wherein the first cavity and the second cavity both contain a pressure protection liquid; An air inlet pipe, wherein the air inlet pipe is arranged on the shell, the inlet of the air inlet pipe is used to communicate with the gas phase space of the protected device, the outlet of the air inlet pipe is communicated with the first cavity, the outlet of the air inlet pipe is located above the pressure protection liquid in the first cavity, and the gas in the gas phase space of the protected device can pass into the space above the pressure protection liquid in the first cavity; An air pipe, wherein the upper opening of the air pipe is located outside the shell, the lower opening of the air pipe extends downward into the first cavity, the lower opening of the air pipe is located below the liquid level of the pressure protection liquid in the first cavity, and the distance between the lower opening of the air pipe and the liquid level of the pressure protection liquid in the first cavity in the vertical direction is a first preset value; An air outlet pipe, the air outlet pipe is arranged on the shell, and the inlet of the air outlet pipe is connected to the upper space of the pressure protection liquid in the second cavity; A pressure-reducing pipe, at least part of which is disposed in the second cavity, an upper opening of the pressure-reducing pipe is connected to the air inlet pipe, gas in the gas phase space of the protected equipment can be passed into the pressure-reducing pipe, a lower opening of the pressure-reducing pipe is located below the liquid level of the pressure protection liquid in the second cavity, and a distance between the lower opening of the pressure-reducing pipe and the liquid level of the pressure protection liquid in the second cavity in the vertical direction is a second preset value; when the liquid level in the first cavity is flush with the upper opening of the pressure-reducing pipe, it is the liquid level height of the pressure protection liquid in the first cavity; The upper opening of the air pipe is connected to the atmosphere or the protective gas inlet, and the air pressure of the upper opening of the air pipe is the atmospheric pressure; The shell is provided with a liquid inlet pipe, and the outlet of the liquid inlet pipe is connected with the first cavity; The shell is provided with a drain pipe, and the inlet of the drain pipe is connected with the second cavity; A first baffle is provided in the second cavity, the thickness direction of the first baffle is the horizontal direction, the lower edge and the edge in the horizontal direction of the first baffle are connected to the wall surface of the second cavity, the upper edge of the first baffle is spaced from the second cavity, the first baffle divides the lower part of the second cavity into a first sub-cavity and a second sub-cavity, the upper part of the first sub-cavity is connected to the upper part of the second sub-cavity, the pressure protection liquid in the second cavity is located in the first sub-cavity, the lower opening of the pressure reducing tube is located in the first sub-cavity, the lower opening of the pressure reducing tube is located below the upper edge of the first baffle, the distance between the lower opening of the pressure reducing tube and the upper edge of the first baffle is the second preset value, and the inlet of the drain pipe is connected to the second sub-cavity; when the liquid level in the first sub-cavity is flush with the upper edge of the first baffle, it is the liquid level height of the pressure protection liquid in the second cavity; The shell is provided with a first sewage pipe, and the first sewage pipe is connected with the bottom of the first cavity; The shell is provided with a second sewage pipe, and the second sewage pipe is communicated with the bottom of the first sub-cavity.

2. The pressure protection device for energy storage according to claim 1, characterized in that: A partition is provided in the shell, and the thickness direction of the partition is the up and down direction. The partition divides the cavity of the shell into the first cavity and the second cavity. The upper opening of the pressure-reducing pipe is located in the first cavity, and the upper opening of the pressure-reducing pipe is located above the lower opening of the air pipe. The distance between the lower opening of the air pipe and the upper opening of the pressure-reducing pipe in the up and down direction is the first preset value.

3. The pressure protection device for energy storage according to claim 1, characterized in that: The outer circumferences of the liquid inlet pipe and the liquid discharge pipe are both provided with heating equipment and a thermal insulation layer; The shell is provided with a sight glass for observing the second cavity, and / or the drain pipe is provided with a sight glass.

4. The pressure protection device for energy storage according to claim 1, characterized in that: A support is provided at the bottom of the shell, and the shell is located above the protected equipment; The outlet of the gas outlet pipe is connected to the gas processing equipment; The first sewage pipe is provided with a first opening and closing valve; The second sewage pipe is provided with a second opening and closing valve.

5. The pressure protection device for energy storage according to claim 1, characterized in that: A second baffle is provided in the first cavity, and the thickness direction of the second baffle is horizontal. The lower edge and the edge in the horizontal direction of the second baffle are connected to the wall of the first cavity, and the upper edge of the second baffle is spaced apart from the first cavity. The second baffle divides the lower part of the first cavity into a third sub-cavity and a fourth sub-cavity, and the upper part of the third sub-cavity is connected to the upper part of the fourth sub-cavity. The pressure protection liquid in the first cavity is located in the third sub-cavity, and the lower opening of the air pipe is located in the third sub-cavity. The lower opening of the air pipe is located below the upper edge of the second baffle, and the distance between the lower opening of the air pipe and the upper edge of the second baffle is the first preset value.

6. The pressure protection device for energy storage according to claim 1, characterized in that: The pressure protection liquid includes at least one of a liquid phase energy storage medium, water, an aqueous solution, an organic liquid and a molten liquid; The relationship between the negative pressure safety value of the design air pressure of the protected equipment and the first preset value satisfies the first formula; The first formula: P1=ρgh1, where P1 is the negative pressure safety value of the design air pressure of the protected equipment, ρ is the density of the pressure protection liquid, g is the acceleration of gravity, and h1 is the first preset value; The positive pressure safety value of the design air pressure of the protected equipment and the second preset value satisfy the second formula; The second formula: P2=ρgh2, where P2 is the positive pressure safety value of the design air pressure of the protected equipment, ρ is the density of the pressure protection liquid, g is the acceleration of gravity, and h2 is the second preset value.

7. An energy storage device, characterized in that: include Protected equipment; A pressure protection device for energy storage, wherein the pressure protection device for energy storage is the pressure protection device for energy storage according to any one of claims 1 to 6, and the gas phase space of the protected device is connected to the air inlet pipe of the pressure protection device for energy storage.

8. The energy storage device according to claim 7, characterized in that: The pressure protection device for energy storage is provided with a liquid return pipe, and the liquid return pipe is connected to the liquid inlet of the protected device; There are multiple protected devices, the meteorological spaces of the multiple protected devices are connected in series in sequence, and the gas phase space of one of the multiple protected devices is connected to the air inlet pipe of the pressure protection device for energy storage through a pipeline; Alternatively, there are multiple protected devices, and the gas phase space of each of the protected devices is connected to the air inlet pipe of the pressure protection device for energy storage through a pipeline.

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