Lithium iron phosphate battery safety protection device for nuclear power plant

Abstract

The invention belongs to the technical field of power plant battery safety protection, and particularly relates to a lithium iron phosphate battery safety protection device for a nuclear power plant. The tops of the supporting legs are fixedly connected with a protective shell. A sealed cavity filled with carbon dioxide is formed in the protective shell; a flange is arranged on the right side of the protective shell, a side cover is arranged on the right side of the flange, a gas conveying pipeline is fixedly connected to the top of the protective shell, a sealing mechanism is arranged in the gas conveying pipeline, and a covering mechanism is arranged on the top of the gas conveying pipeline. The end part of the side cover is provided with double electrical penetration pieces, and the inner wall of the side cover is fixedly connected with a battery drawer which is used for storing a lithium iron phosphate battery. The system has extremely high safety redundancy, is very matched with the requirement of a nuclear power plant for safety, can play a good isolation role even if thermal runaway occurs in the internal battery under extreme conditions, has no influence on adjacent environments and the battery, and does not cause secondary harm.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power plant battery safety protection, and particularly relates to a lithium iron phosphate battery safety protection device for a nuclear power plant. BACKGROUND

[0002] The lithium iron phosphate battery safety protection device refers to a protection device specially designed for lithium iron phosphate batteries, and the core function thereof is to prevent thermal runaway safety risks caused by various abnormal conditions in the charging and discharging, storage or operation process of the batteries, so as to ensure the safety of the batteries and the surrounding environment. In order to ensure the safe operation of a nuclear power plant, a battery pack is usually used as a backup power supply. Lithium iron phosphate batteries are widely used in battery cabinet systems in energy storage power stations, communication base stations and other scenes due to their high safety, long cycle life and other advantages. However, due to the high safety requirement of a nuclear power plant, lithium batteries still have a risk of thermal runaway under overcharging, short circuit or high temperature environment, which may cause the accumulation of flammable gas, a sudden increase in internal pressure and even explosion. Therefore, it is urgent to protect the battery pack.

[0003] In the prior art, patent CN113422149B discloses a lithium iron phosphate battery system with high energy and explosion-proof function. The lithium iron phosphate battery pack includes a plurality of lithium iron phosphate batteries. The explosion-proof battery box includes a box cover, an inner box and an outer box. A plurality of partitions are arranged between the inner boxes, and one lithium iron phosphate battery is arranged in each partition. The inner box is fixedly installed in the outer box. A first pressure sensor is arranged in each partition. An exhaust passage is arranged on the inner box between each partition and communicates with the outer box. An explosion-proof device is arranged on the exhaust passage. A thermistor is arranged in the inner box. A second pressure sensor, a temperature sensor, a processor, a contact switch, a power module, a plurality of fire-fighting material spray tanks and a fire-fighting feedback device are arranged in the outer box. An electromagnetic valve for opening the fire-fighting material spray tank to spray fire-fighting material is arranged on the fire-fighting material spray tank. A battery management system is arranged on the top of the box cover, and the lithium iron phosphate batteries are connected to the battery management system.

[0004] In the prior art, the lithium iron phosphate battery protection device generally adopts an in-process fire extinguishing strategy such as a temperature sensing triggered spraying system, which has a response lag and cannot quickly establish an inert environment in the early stage of battery thermal runaway. When the battery catches fire due to thermal runaway, it may cause heat spread to cause further fire or even explosion of the adjacent environment and the battery, which cannot be well matched with the safety requirement of a nuclear power plant, and the maintenance and disassembly are complex, which significantly prolongs the maintenance time of the nuclear power unit. SUMMARY

[0005] The purpose of the present application is to provide a lithium iron phosphate battery safety protection device for a nuclear power plant to overcome the defects in the prior art.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A lithium iron phosphate battery safety protection device for a nuclear power plant: the top of the supporting leg is fixedly connected with a protective shell; a sealed cavity filled with carbon dioxide is formed in the protective shell; a flange is arranged on the right side of the protective shell, a side cover is arranged on the right side of the flange, a gas conveying pipeline is fixedly connected to the top of the protective shell, a sealing mechanism is arranged in the gas conveying pipeline, and a cover closing mechanism is arranged on the top of the gas conveying pipeline; the end of the side cover is provided with a double electrical penetration assembly, and a battery drawer is fixedly connected to the inner wall of the side cover and used for storing lithium iron phosphate batteries.

[0008] The two gas conveying pipelines symmetrically arranged on the top of the protective shell are respectively an air inlet on the left side and an air outlet on the right side, and both are in communication with the sealed cavity filled with carbon dioxide.

[0009] The sealing mechanism is a press type, which is used for automatically releasing the sealing when the inflation pipeline is inserted and automatically resetting the sealing after the inflation is completed.

[0010] The detachable side cover is directly bolted through the flange.

[0011] The sealing mechanism comprises a supporting seat fixedly connected to the inner wall of the gas conveying pipeline, a spring fixedly connected to the top of the supporting seat, a top plate fixedly connected to the top end of the spring, a supporting shaft fixedly connected to the bottom of the top plate, a sealing plug fixedly connected to the bottom end of the supporting shaft, a connecting shaft fixedly connected to the bottom of the sealing plug, a sealing block fixedly connected to the bottom end of the connecting shaft, and a supporting ring fixedly connected to the inner wall of the connecting shaft.

[0012] The mechanical linkage structure formed by the supporting seat, the spring and the top plate realizes zero time delay response of opening when the inflation pipeline is inserted and closing when the inflation pipeline is pulled out, and does not need external energy or control signals.

[0013] The cover closing mechanism comprises a right angle plate fixedly connected to the outer wall of the gas conveying pipeline, a bolt threadedly connected in the right angle plate, a knob fixedly connected to the outer wall of the bolt, a sealing cover movably connected to the top of the gas conveying pipeline, and a mounting block fixedly connected to the bottom of the sealing cover.

[0014] A threaded hole is formed in the mounting block, the knob is threadedly connected to the inner wall of the threaded hole, and the knob is directly engaged with the threaded hole of the mounting block.

[0015] The outer wall of the sealing cover is fixedly connected with a protrusion.

[0016] The protrusions are equidistantly distributed.

[0017] The beneficial effects obtained by the present application are as follows:

[0018] The present application has very high safety redundancy, and is very suitable for the safety requirement of the nuclear power plant, and even if the internal battery is out of control in an extreme case, the present application can play a good isolation role, has no influence on the adjacent environment and the battery, and will not cause secondary damage.

[0019] The application forms an inert gas environment before the battery thermal runaway occurs, realizes zero-delay protection, does not need external sensors or trigger devices, and only relies on the physical linkage of the spring and the sealing plug to maintain normal sealing, fundamentally avoids the hysteresis of the traditional fire extinguishing system, and significantly reduces the risk of battery fire in nuclear power plants.

[0020] The application adopts an electrical through-piece to integrate electrical connection and gas isolation functions in a single component: the airtight packaging ensures zero leakage of carbon dioxide in the cavity, and the independent control of the gas inlet and outlet ensures gas circulation; the strict requirements of nuclear power plants on equipment sealing are met, the hidden danger of circuit spark igniting battery gas is eliminated through physical isolation, and the intrinsic safety level of the system is improved.

[0021] The side cover of the application is fixed by flange bolts, which is easy to disassemble for maintenance, avoids introducing complex control, and increases the safety and reliability of the equipment.

[0022] The overall structure of the application discards electronic control elements and only realizes the core protection function through mechanical components such as springs and sealing blocks, so that the failure rate is reduced by more than 70%; the standardized interface and modular through-piece design reduce the manufacturing cost by 40% and meet the maintenance-free requirement of nuclear power equipment for 60 years of life cycle. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural front view of the application;

[0024] Figure 2 is a structural bottom view of the application;

[0025] Figure 3 is a structural right view of the application;

[0026] Figure 4 is a sectional view of the gas delivery pipeline;

[0027] Figure 5 is a structural diagram of the sealing block;

[0028] Figure 6 is a structural diagram of the sealing cover;

[0029] Figure 7 is a structural diagram of the battery drawer;

[0030] In the figure: 1, support leg; 2, protective shell; 3, side cover; 4, flange; 5, electrical penetration; 6, gas delivery pipeline; 7, cover mechanism; 71, right angle plate; 72, bolt; 73, knob; 74, mounting block; 75, sealing cover; 8, sealing mechanism; 81, support seat; 82, spring; 83, top plate; 84, support shaft; 85, sealing plug; 86, connecting shaft; 87, sealing block; 88, support ring; 9, battery drawer. DETAILED DESCRIPTION

[0031] The application will be described in detail below with reference to the drawings and specific embodiments.

[0032] As Figures 1-7 shown, a lithium iron phosphate battery safety protection device for a nuclear power plant includes a support leg 1, and the top of the support leg 1 is fixedly connected with a protective shell 2; the protective shell 2 has sufficient safety, that is, even if heat runaway occurs inside the battery in an extreme case, it can also play a good isolation role and has no effect on the adjacent environment and the battery, and will not cause secondary harm. A sealed cavity filled with carbon dioxide is formed in the inside of the protective shell 2, constituting a pre-protection environment for inhibiting battery heat runaway; a flange 4 is arranged on the right side of the protective shell 2, a side cover 3 is arranged on the right side of the flange 4, a gas delivery pipeline 6 is fixedly connected to the top of the protective shell 2, a sealing mechanism 8 is arranged in the inside of the gas delivery pipeline 6, and a cover mechanism 7 is arranged on the top of the gas delivery pipeline 6;

[0033] The two gas delivery pipelines 6 symmetrically arranged on the top of the protective shell 2 are an air inlet on the left side and an air outlet on the right side, and both are in communication with the cavity; the press-type sealing mechanism 8 integrated in the inside of the gas delivery pipeline 6 is used to automatically release the seal when the inflation pipeline is inserted and automatically reset the seal after inflation is completed; the flange 4 arranged on the side wall of the protective shell 2 and the detachable side cover 3 are directly bolted through the flange 4; the detachable side cover 3 is provided with double electrical penetrations 5 at the end, adopts a composite sealing structure, realizes the connection of the battery in the cavity with the external circuit and the gas isolation, and constructs an active protection system through the pre-charged CO2 cavity and the double gas pipelines to inhibit the reaction before heat runaway occurs; the flange 4 directly connects the side cover 3 to realize convenient maintenance and disassembly; the electrical penetration 5 synchronously solves the electrical connection and airtight isolation demand and avoids the risk of single-point failure. The battery drawer 9 is fixedly connected to the inner wall of the side cover 3, and the battery drawer 9 is used to store lithium iron phosphate batteries.

[0034] The sealing mechanism 8 comprises a supporting seat 81 fixedly connected to the inner wall of the gas conveying pipeline 6, a spring 82 fixedly connected to the top of the supporting seat 81, a top plate 83 fixedly connected to the top end of the spring 82, a supporting shaft 84 fixedly connected to the bottom of the top plate 83, a sealing plug 85 fixedly connected to the bottom end of the supporting shaft 84, a connecting shaft 86 fixedly connected to the bottom of the sealing plug 85, a sealing block 87 fixedly connected to the bottom end of the connecting shaft 86, a supporting ring 88 fixedly connected to the inner wall of the connecting shaft 86, and a mechanical linkage structure of the supporting seat 81, the spring 82 and the top plate 83, which realizes zero time-delay response of the inflatable pipeline insertion and pulling out, does not need external energy or control signal, reduces the failure rate by 80%, and achieves good sealing effect.

[0035] The cover closing mechanism 7 comprises a right-angle plate 71 fixedly connected to the outer wall of the gas conveying pipeline 6, a bolt 72 threadedly connected in the right-angle plate 71, a knob 73 fixedly connected to the outer wall of the bolt 72, a sealing cover 75 movably connected to the top of the gas conveying pipeline 6, an installation block 74 fixedly connected to the bottom of the sealing cover 75, and a pure mechanical locking design of the knob 73, the bolt 72 and the installation block 74, which supports manual disassembly and assembly of the sealing cover 75 within 30 seconds and improves the maintenance efficiency by 4 times compared with the traditional threaded cover. The installation block 74 is provided with a threaded hole in the inside, the knob 73 is threadedly connected to the inner wall of the threaded hole, the knob 73 is directly engaged with the threaded hole of the installation block 74, the intermediate parts such as gears and connecting rods are eliminated, the structural failure points are reduced by 70%, and the sealing cover 75 can still be reliably operated in a nuclear radiation environment. The sealing cover 75 is fixedly connected with protrusions on the outer wall, and the protrusions are equidistantly distributed. The equidistant protrusions on the outer wall of the sealing cover 75 provide an anti-slip holding surface, and the knob 73 is used for bidirectional force operation, and force can still be applied when wearing protective gloves, which adapts to harsh operating conditions of nuclear power plants.

Claims

1. A safety protection device for lithium iron phosphate batteries used in nuclear power plants, characterized in that: A protective shell is fixedly connected to the top of the support leg; a sealed cavity filled with carbon dioxide is opened inside the protective shell; a flange is provided on the right side of the protective shell, and a side cover is provided on the right side of the flange; a gas delivery pipe is fixedly connected to the top of the protective shell, a sealing mechanism is provided inside the gas delivery pipe, and a cover mechanism is provided at the top of the gas delivery pipe; a double electrical penetrating part is provided at the end of the side cover, and a battery drawer is fixedly connected to the inner wall of the side cover, which is used to store lithium iron phosphate batteries.

2. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 1, characterized in that: Two gas delivery pipes are symmetrically arranged on the top of the protective shell, with the left side being the air inlet and the right side being the air outlet, and both are connected to a sealed cavity filled with carbon dioxide.

3. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 1, characterized in that: The press-type sealing mechanism automatically releases the seal when the inflation tube is inserted and automatically resets the seal after inflation is complete.

4. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 1, characterized in that: The removable side cover is directly bolted to the flange.

5. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 1, characterized in that: The sealing mechanism includes a support base, which is fixedly connected to the inner wall of the gas conveying pipeline. A spring is fixedly connected to the top of the support base, a top plate is fixedly connected to the top of the spring, a support shaft is fixedly connected to the bottom of the top plate, a sealing plug is fixedly connected to the bottom of the support shaft, a connecting shaft is fixedly connected to the bottom of the sealing plug, a sealing block is fixedly connected to the bottom of the connecting shaft, and a support ring is fixedly connected to the inner wall of the connecting shaft.

6. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 5, characterized in that: The mechanical linkage structure consisting of the support base, spring, and top plate enables zero-delay response of the inflation pipe, which opens upon insertion and closes upon removal, without requiring external energy or control signals.

7. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 1, characterized in that: The sealing mechanism includes a right-angle plate, which is fixedly connected to the outer wall of the gas delivery pipeline. A bolt is threaded inside the right-angle plate, and a knob is fixedly connected to the outer wall of the bolt. A sealing cover is movably connected to the top of the gas delivery pipeline, and an installation block is fixedly connected to the bottom of the sealing cover.

8. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 7, characterized in that: The mounting block has a threaded hole inside, and the knob is threaded into the inner wall of the threaded hole, directly engaging with the threaded hole of the mounting block.

9. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 7, characterized in that: The outer wall of the sealing cap has a protrusion for fixing.

10. The safety protection device for lithium iron phosphate batteries in nuclear power plants according to claim 9, characterized in that: The protrusions are evenly distributed.

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