Electrochemical energy storage battery cabin explosion venting device and design method

Abstract

The invention discloses an electrochemical energy storage battery cabin explosion venting device and a design method, and belongs to the field of battery cabin explosion venting. The explosion venting device comprises a battery cabin and an explosion venting device body, wherein the explosion venting device body is installed outside a cabin door of the battery cabin. The invention aims to solve the problem that battery compartment explosion may be induced after thermal runaway of a lithium ion battery, and by arranging the explosion venting device, when thermal runaway occurs in the energy storage prefabricated compartment, high-temperature and high-pressure gas generated inside can be released in time, and explosion caused by too high pressure of the energy storage box body is prevented. The structure integrity of an energy storage system can be effectively protected, safe and stable operation of an energy storage power station is guaranteed, large-scale accidents are avoided, the battery cabin and the explosion venting device are detachably connected and matched with the design of a sealing gasket, the sealing performance is guaranteed, meanwhile, the maintenance cost and the downtime are reduced, and the service life is prolonged. And the overall availability and the long-term operation stability of the system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrochemical energy storage battery cabin explosion venting device and design method, belonging to the field of battery cabin explosion venting. BACKGROUND

[0002] Lithium ion batteries have been widely used in electrochemical energy storage power stations due to their high energy density, long life cycle and low self-discharge rate. In recent years, safety accidents of lithium ion batteries have occurred frequently, especially the safety of high specific energy lithium ion batteries, which is a bottleneck problem restricting the development of electrochemical energy storage. Studies have shown that when lithium ion batteries occur thermal runaway, a large amount of heat and flammable gas will be released, causing the pressure in the battery chamber to rise sharply. If the pressure cannot be released in time and effectively, it may cause an explosion, causing serious threats to personnel and property safety.

[0003] In view of such problems, the explosion venting design of the battery cabin is a very important safety protection measure in the energy storage system, which can effectively reduce the probability of accidents caused by battery thermal runaway, prevent the explosion of the battery cabin, and prevent the occurrence of larger-scale disasters. Therefore, it is urgent to propose an electrochemical energy storage battery cabin explosion venting device and design method to solve the above technical problems. SUMMARY

[0004] The purpose of the present application is to solve the problem that lithium ion battery thermal runaway may induce the explosion of the battery cabin. In the following, a brief summary of the present application is given to provide a basic understanding of some aspects of the present application. It should be understood that this summary is not an exhaustive summary of the present application. It is not intended to determine the key or important parts of the present application, nor to limit the scope of the present application.

[0005] The technical scheme of the present application:

[0006] Scheme one, an electrochemical energy storage battery cabin explosion venting device, comprising a battery cabin and an explosion venting device, the cabin door of the battery cabin is externally mounted with the explosion venting device.

[0007] The explosion venting device is a rectangular high-strength aluminum alloy or stainless steel plate with a thickness of 2-6mm.

[0008] Preferably, the surface of the explosion venting device is arranged with a reinforcing rib structure, the reinforcing rib adopts a transverse, longitudinal or cross form, the height is between 5-15mm, and the width is between 2-6mm.

[0009] Preferably, the battery cabin and the explosion venting device adopt a detachable connection mode, and a sealing gasket is arranged at the connection.

[0010] Preferably, the detachable connection mode is bolt connection, and the fastening degree of the bolt connection is adjusted to ensure the sealing performance.

[0011] Preferably, the number of battery compartments is multiple, and adjacent battery compartments are isolated.

[0012] Scheme two, a design method of an electrochemical energy storage battery compartment explosion relief device, is realized by relying on the electrochemical energy storage battery compartment explosion relief device described in scheme one, and includes the following steps:

[0013] Step 1, the explosion relief device is designed to be rectangular, the thickness of the explosion relief device is determined by finite element analysis and other methods according to the volume of the battery compartment, the maximum allowable pressure and the mechanical properties of the selected material;

[0014] Step 2, the reinforcing rib structure is arranged on the surface of the explosion relief device, and the height h and the width b of the reinforcing rib structure are designed according to the size and stress condition of the explosion relief device;

[0015] Step 3, the explosion relief device designed and processed is installed on the outside of the hatch of the battery compartment through bolt connection.

[0016] Preferably, the calculation method of the thickness of the explosion relief device in step 1 is as follows:

[0017]

[0018] Wherein: t is the thickness of the explosion relief device, P is the explosion pressure, A is the explosion area, S is the tensile strength of the explosion relief device material, and B is the safety factor.

[0019] Preferably, the height h and the width b of the reinforcing rib structure in step 2 are designed according to the size and stress condition of the explosion relief device as follows:

[0020] The height h and the width b of the reinforcing rib structure satisfy the following formula:

[0021]

[0022] Wherein: P is the explosion pressure, L is the distance between the reinforcing ribs in the reinforcing rib structure, and S is the tensile strength of the reinforcing rib structure material.

[0023] The present application has the following beneficial effects:

[0024] 1. By arranging the explosion relief device, when the energy storage prefabricated cabin is in thermal runaway, the high-temperature and high-pressure gas generated inside can be released in time, and the explosion of the energy storage box due to excessive pressure can be prevented. The structural integrity of the energy storage system can be effectively protected, the safe and stable operation of the energy storage power station can be ensured, and large-scale accidents can be avoided;

[0025] 2.The application can accurately control the pressure threshold of the explosion relief device, i.e., the explosion relief pressure, to ensure that the device breaks when needed, avoids premature failure or late activation, and achieves the best balance between explosion relief performance and structural integrity, while ensuring that the device has sufficient strength to withstand daily operating stress.

[0026] 3.The battery cabin and the explosion relief device of the application use a detachable connection method, and are designed in combination with a sealing gasket to ensure sealing while reducing maintenance costs and downtime, improving the overall availability and long-term stability of the system.

[0027] 4.The battery cabin of the application has multiple isolation designs, and when a single battery cabin experiences thermal runaway, the explosion relief device can quickly respond and relieve pressure, strictly limiting the accident within the independent cabin. This effectively prevents high-temperature jets, flames, or flammable gases from spreading to adjacent cabins, avoiding the "domino effect" that can cause large-scale fires or explosions, greatly improving the safety of the entire energy storage power station system. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of an electrochemical energy storage battery cabin explosion relief device.

[0029] In the figure, 1 is a battery cabin, and 2 is an explosion relief device. DETAILED DESCRIPTION

[0030] To make the purpose, technical solutions and advantages of the application clearer and more understandable, the following describes the application through specific embodiments shown in the drawings. However, it should be understood that these descriptions are only exemplary and do not limit the scope of the application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the application.

[0031] The connection mentioned in the application is divided into fixed connection and detachable connection. The fixed connection, i.e., the non-detachable connection, includes but is not limited to conventional fixed connection methods such as flange connection, rivet connection, adhesive connection, and welding connection. The detachable connection includes but is not limited to conventional detachable methods such as threaded connection, buckle connection, pin connection, and hinge connection. When the specific connection method is not explicitly limited, at least one connection method can be found in the existing connection methods to achieve the function, and the person skilled in the art can choose as needed. For example, the fixed connection selects welding connection, and the detachable connection selects hinge connection.

[0032] Specific implementation one: combination Figure 1To illustrate the embodiment, the electrochemical energy storage battery cabin explosion relief device of the embodiment comprises a battery cabin 1 and an explosion relief device 2. The explosion relief device 2 is installed outside the cabin door of the battery cabin 1. When an emergency such as thermal runaway occurs in the battery cabin 1 and the pressure reaches a predetermined threshold, the explosion relief device 2 can be quickly and reliably opened to release the high-pressure gas and energy in the battery cabin 1, preventing large-scale explosion of the battery cabin 1 due to excessive pressure, while being able to withstand certain external impact and vibration to ensure that the battery cabin 1 does not accidentally damage or open during transportation, installation and operation of the energy storage system.

[0033] The explosion relief device 2 is a rectangular high-strength aluminum alloy or stainless steel plate with a thickness of 2-6 mm. The thickness ensures the structural strength under normal pressure and ensures that the device can be smoothly broken or opened under the predetermined explosion relief pressure. The stainless steel plate has better high-temperature resistance and corrosion resistance, which can adapt to the complex chemical environment and high temperature that may occur in the battery cabin 1. The rectangular explosion relief device 2 is more convenient to adapt and install with the structure of the battery cabin 1.

[0034] The surface of the explosion relief device 2 is arranged with a reinforcing rib structure. The reinforcing rib is in a transverse, longitudinal or cross form, with a height of 5-15 mm and a width of 2-6 mm, which improves the overall bending strength and pressure resistance without affecting the explosion relief performance.

[0035] The battery cabin 1 and the explosion relief device 2 are connected in a detachable manner, and a sealing gasket is arranged at the connection to ensure good sealing performance. In the normal operating state, the sealing performance of the battery cabin is ensured to prevent dust, moisture and external impurities from entering the battery cabin 1 to affect the battery performance and the safety of the whole cabin. At the same time, high-temperature and aging-resistant sealing gaskets such as silicone rubber are used at the contact part of the explosion relief device 2 and the frame of the battery cabin 1 to ensure good sealing effect under normal conditions, and to smoothly separate during explosion without affecting the explosion process.

[0036] The detachable connection is a bolt connection, which is convenient for installation and disassembly, and the sealing performance can be ensured by adjusting the fastening degree of the bolt. A weak link is arranged at the detachable connection part, such as a low-strength bolt or a structure with a breakable structure reserved at the clamping groove, to ensure that the connection part fails first during the explosion, so that the explosion relief device 2 can be opened smoothly.

[0037] The number of battery cabins 1 is multiple, and the adjacent battery cabins 1 are isolated. The purpose is to ensure that the influence on the surrounding battery clusters is minimized after the battery thermal runaway, and to reduce the influence on the surrounding battery clusters as much as possible. Therefore, the battery cabins 1 are designed to be separated and isolated, and two clusters of back-to-back batteries are divided into one battery cabin 1. Each battery cabin 1 is provided with one set of explosion relief device 2.

[0038] Specific implementation method two: combination Figure 1 In order to illustrate the present embodiment, the design method of the electrochemical energy storage battery cabin explosion relief device of the present embodiment is implemented based on the electrochemical energy storage battery cabin explosion relief device described in the specific implementation method one, and includes the following steps:

[0039] Step 1, design the explosion relief device 2 as a rectangle, according to the volume of the battery cabin, the maximum allowable pressure and the mechanical properties of the selected material, determine the thickness of the explosion relief device 2 through finite element analysis and other methods;

[0040] Step 2, arrange the reinforcing rib structure on the surface of the explosion relief device 2, and the height h and width b of the reinforcing rib structure are designed according to the size and stress condition of the explosion relief device 2;

[0041] Step 3, install the explosion relief device 2 designed and processed through bolt connection on the outside of the cabin door of the battery cabin 1.

[0042] The calculation method of determining the thickness of the explosion relief device 2 in step 1 is as follows:

[0043]

[0044] Wherein: t is the thickness of the explosion relief device 2, P is the explosion pressure, A is the explosion area, S is the tensile strength of the explosion relief device 2 material, B is the safety factor, usually 1.5~3, determined according to the specific working condition.

[0045] When the explosion pressure P is determined as 0.01MPa, the explosion area S is 640000mm 2 , the selected material is stainless steel, the tensile strength S is 600MPa, and the safety factor B is 2, the thickness of the explosion relief plate is as follows:

[0046]

[0047] The height h and width b of the reinforcing rib structure in step 2 are designed according to the size and stress condition of the explosion relief device 2 as follows:

[0048] The height h and width b of the reinforcing rib structure satisfy the following formula:

[0049]

[0050] Wherein: P is the explosion pressure, L is the distance between each reinforcing rib in the reinforcing rib structure, and S is the tensile strength of the reinforcing rib structure material.

[0051] When the explosion relief pressure P is determined to be 0.01MPa; the spacing of the designed reinforcement ribs is L=200mm, the material is selected as stainless steel, and the tensile strength is S=600MPa; when the height of the designed reinforcement rib is 10mm, the calculated reinforcement rib width b is ≥0.3mm: the general value is 3mm.

[0052] Specific implementation method three: Combination Figure 1 This embodiment, based on Specific Embodiment 2, describes a method for designing an explosion venting device for an electrochemical energy storage battery compartment. This method designs explosion venting device 2 based on the compartment volume information of battery compartment 1, the battery combustion rate (SU), the maximum pressure Pmax, the battery, and other intermediate parameters. The explosion venting mechanism is that when the pressure within battery compartment 1 reaches the opening pressure of explosion venting device 2, explosion venting device 2 passively explodes, releasing the pressure and heat within battery compartment 1 in a predetermined direction while ensuring that the hatch of battery compartment 1 does not open under pressure, minimizing damage to surrounding personnel and property when combustible gases within battery compartment 1 explode. The calculation of explosion venting device 2 is as follows:

[0053] Design and working conditions of explosion relief device 2: the opening pressure range of the device is 0.1bar±25%@22℃bar, the working pressure is normal pressure, and the total volume of the equipment is 8.655m 3 , operating temperature is -20~85℃, and the anti-corrosion grade is IP67.

[0054] Medium properties: The medium is flammable gas, the maximum explosion pressure Pmax is 7.01barG, and the pressure rise rate is 159.64bar / s.

[0055] Discharge area A of explosion relief device 2 v0 The calculation is as follows:

[0056]

[0057] .1

[0058] Among them, the inner surface area A of the battery compartment 1 s m 2 is 23.33, the maximum controlled explosion pressure P red The discharge coefficient C is 0.3 barG. d is 0.7, the basic combustion velocity of the gas and air mixture Sum / s is 0.79, and the mass density of the unburned gas-air mixture p u 1.2kg / m 3 The mass flow rate of the unburned gas-air mixture at the speed of sound is 230.1 kg / m 3 .

[0059] Therefore, the required explosion relief device area is calculated to be: 0.64m2 The total area of one piece of the explosion venting device 2 with a configuration of 915 (mm) * 820 (mm) is 0.75 m 2 , which meets the explosion venting requirement.

[0060] The opening pressure of the explosion venting device is selected as 10 kPa, the air conditioner model is simplified, the size of the door plate is 2.5 * 1.28 = 3.2 m 2 , and when the opening pressure of the explosion venting device is reached, the force on the door plate is 10 kPa * 3.2 m 2 = 32000 N. The yield strength and shear strength of the door plate and the lock rod are 235 MPa and 823 MPa. Through simulation, when the explosion venting pressure in the cabin is reached, the door plate and the door lock do not have plastic deformation, and the residual deformation after pressure relief can be ignored, which does not affect the normal opening of the door.

[0061] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined. Those skilled in the art can exhaust all possibilities according to the mathematical knowledge of arrangement and combination, and therefore the present application does not need to explain the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present application.

[0062] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Those skilled in the art can make various changes and modifications to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An electrochemical energy storage battery compartment explosion relief device, characterized in that: It comprises a battery compartment (1) and an explosion relief device (2), wherein the explosion relief device (2) is installed outside the door of the battery compartment (1); The explosion relief device (2) is a rectangular high-strength aluminum alloy or stainless steel plate with a thickness of 2-6 mm.

2. The electrochemical energy storage battery compartment explosion relief device according to claim 1, characterized in that: The surface of the explosion relief device (2) is provided with a reinforcing rib structure, wherein the reinforcing rib is arranged in a transverse, longitudinal or cross form, with a height between 5-15 mm and a width between 2-6 mm.

3. The electrochemical energy storage battery compartment explosion relief device according to claim 2, characterized in that: The battery compartment (1) and the explosion relief device (2) are connected in a detachable manner, and a sealing gasket is provided at the connection.

4. The electrochemical energy storage battery compartment explosion relief device according to claim 3, characterized in that: The detachable connection method is a bolt connection, and the tightness of the bolt connection is adjusted to ensure the sealing performance.

5. The electrochemical energy storage battery compartment explosion relief device according to claim 4, characterized in that: There are a plurality of battery compartments (1), and adjacent battery compartments (1) are isolated from each other.

6. A method for designing an explosion relief device for an electrochemical energy storage battery compartment is implemented based on the explosion relief device for an electrochemical energy storage battery compartment according to claim 5, characterized in that: The following steps are involved: Step 1: Design the explosion relief device (2) to be rectangular, and determine the thickness of the explosion relief device (2) by finite element analysis or other methods based on the volume of the battery compartment, the maximum allowable pressure, and the mechanical properties of the selected material; Step 2, arranging a reinforcing rib structure on the surface of the explosion relief device (2), wherein the height h and width b of the reinforcing rib structure are designed according to the size and stress conditions of the explosion relief device (2); Step 3: Install the designed and processed explosion relief device (2) on the outside of the door of the battery compartment (1) through bolt connection.

7. The method for designing an explosion relief device for an electrochemical energy storage battery compartment according to claim 6, characterized in that: The calculation method for determining the thickness of the explosion relief device (2) in step 1 is as follows: Wherein: t is the thickness of the explosion relief device (2), P is the explosion relief pressure, A is the explosion relief area, S is the tensile strength of the material of the explosion relief device (2), and B is the safety factor.

8. The method for designing an explosion relief device for an electrochemical energy storage battery compartment according to claim 6, characterized in that: The height h and width b of the reinforcing rib structure in step 2 are designed according to the size and stress conditions of the explosion relief device (2) as follows: The relationship between the height h and width b of the reinforcement structure satisfies the following formula: Where: P is the explosion relief pressure, L is the spacing between the ribs in the rib structure, and S is the tensile strength of the rib structure material.

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