CN219979750U - An electrochemical energy storage prefabricated cabin and its explosion relief device - Google Patents

Abstract

The utility model discloses an electrochemical energy storage prefabricated cabin and an explosion venting device thereof, wherein an explosion venting window is arranged in the middle of a frame, a door plate is positioned at one side of the frame and covers the explosion venting window, one end of the door plate is rotatably arranged on the frame, and a reset elastic piece is arranged at the joint of the door plate and the frame; the shutter is positioned at one side of the frame far away from the door plate and is correspondingly arranged with the explosion venting window. Through the explosion venting device for the electrochemical energy storage prefabricated cabin with the optimal design, through the cooperation of the door plate and the explosion venting window, the gas channel is opened/closed along with the pressure change, so that the rapid discharge of gas is realized, the internal pressure of the prefabricated cabin is rapidly reduced, the combustible gas in the prefabricated cabin is prevented from exploding together, the device is reset after the pressure is reduced, the device can be repeatedly used, and the maintenance cost is low.

Description

An electrochemical energy storage prefabricated cabin and its explosion relief device

Technical field

The utility model relates to the technical field of electrochemical energy storage, and in particular to an electrochemical energy storage prefabricated cabin and an explosion venting device thereof.

Background technique

As an important support for the transformation and upgrading of new power grid technology, electrochemical energy storage has been widely used on the power supply side, grid side and user side. Among them, lithium-ion battery energy storage prefabricated cabins have become the main form of electrochemical energy storage applications due to their high energy density, flexible layout, and increasingly mature technology. However, lithium-ion batteries can cause thermal runaway due to triggering factors such as mechanical abuse factors such as extrusion and impact, electrical abuse due to overcharging and over-discharging, and thermal abuse factors that damage the internal structure of the battery cells. When the external heat exchange rate of the battery core is less than the heat accumulation rate, exothermic side reactions inside the battery core will lead to no accumulation of heat, and the temperature will continue to rise until it reaches the ignition temperature, which may cause combustion and explosion. When a lithium-ion battery undergoes thermal runaway, a series of internal chemical reactions will release a large amount of flammable and toxic gases. After these gases are released into the environment through the safety valve on the battery core or the defect in the battery shell, once they encounter ignition source, a fire or even an explosion may occur. In the gas produced by battery thermal runaway, the main components are gases such as CO2, CO, H2, CH4, and C2H4. In some cases, electrolyte vapor is also released, and it also contains toxic gases mainly HF.

Faced with such high-risk, flammable and explosive components with high risk of explosion, when released from the cell safety valve or damage, the pressure will build up in the battery cluster and prefabricated cabin. Not only that, the high-temperature hot smoke generated by the reaction quickly transfers heat to other cells and electrical equipment, and also causes the pressure in the cabin to rise rapidly.

Utility model content

In order to solve the technical problems existing in the background technology, the utility model proposes an electrochemical energy storage prefabricated cabin and its explosion venting device.

The utility model proposes an explosion venting device for electrochemical energy storage prefabricated cabins, which includes: a frame, a door panel and a shutter;

There is an explosion vent window in the middle of the frame. The door panel is located on one side of the frame and covers the explosion vent window arrangement. One end of the door panel can be rotated and installed on the frame. The connection between the door panel and the frame is provided with a reset elastic member;

The shutter is located on the side of the frame away from the door panel and is arranged corresponding to the explosion vent window.

Preferably, the shutters are fixedly connected to the frame by bolts.

Preferably, the upper end of the door panel is rotatably connected to the frame.

Preferably, the outer periphery of the frame is provided with a first installation step extending around the explosion vent window.

Preferably, a second installation step extending around the explosion vent window is provided around the shutter.

In the utility model, the proposed explosion venting device for electrochemical energy storage prefabricated cabins has an explosion venting window in the middle of the frame. The door panel is located on one side of the frame and covers the explosion venting window arrangement. One end of the door panel is rotatably installed on the frame. The connection with the frame is provided with a reset elastic member; the shutter is located on the side of the frame away from the door panel and is arranged corresponding to the explosion vent window. Through the above-mentioned optimized design of the explosion venting device for electrochemical energy storage prefabricated cabins, through the cooperation of the door panel and the explosion venting window, the gas channel is opened/closed as the pressure changes to achieve rapid gas discharge, thereby quickly reducing the internal pressure of the prefabricated cabin and preventing The prefabricated cabin combustible gas explodes and resets after the pressure drops. It can be used repeatedly and has low maintenance costs.

The invention also proposes an electrochemical energy storage prefabricated cabin, which includes a cabin body and the above-mentioned explosion venting device for the electrochemical energy storage prefabricated cabin;

The cabin is provided with an installation opening, the frame is located outside the cabin and is installed at the installation opening, and the door panel is located on the side of the frame away from the cabin.

Preferably, the shutter is located in the cabin, and the shutter, cabin and frame are fixed by bolts.

Preferably, the prefabricated cabin is provided with multiple battery placement cavities, and the side wall of each battery placement cavity is provided with an explosion relief device.

In the present utility model, the technical effect of the electrochemical energy storage prefabricated cabin proposed is similar to that of the above-mentioned explosion venting device, so the details will not be described again.

Description of the drawings

Figure 1 is a schematic structural diagram of an embodiment of an explosion venting device for an electrochemical energy storage prefabricated cabin proposed by the present invention.

Figure 2 is a schematic diagram of the explosion structure in one embodiment of an explosion venting device for electrochemical energy storage prefabricated cabins proposed by the present invention.

Figure 3 is a schematic diagram of the explosion structure in another direction in an embodiment of an explosion venting device for an electrochemical energy storage prefabricated cabin proposed by the present invention.

Detailed ways

As shown in Figures 1 to 3, Figure 1 is a structural schematic diagram of an embodiment of an explosion venting device for an electrochemical energy storage prefabricated cabin proposed by the present utility model. Figure 2 is a schematic diagram of an electrochemical energy storage prefabricated cabin proposed by the present utility model. A schematic diagram of the explosion structure in one embodiment of the explosion venting device for electrochemical energy storage prefabricated cabins. Figure 3 is the explosion structure in another direction in one embodiment of the explosion venting device for electrochemical energy storage prefabricated cabins proposed by the present utility model. Schematic diagram.

Referring to Figures 1 to 3, the utility model proposes an explosion venting device for electrochemical energy storage prefabricated cabins, including: frame 1, door panel 2 and shutter 3;

There is an explosion vent window in the middle of the frame 1. The door panel 2 is located on one side of the frame 1 and covers the explosion vent window arrangement. One end of the door panel 2 is rotatably installed on the frame 1. The connection between the door panel 2 and the frame 1 is provided with a reset elastic member;

The shutter 3 is located on the side of the frame 1 away from the door panel 2 and is arranged corresponding to the explosion vent window.

In order to explain in detail the specific working mode of the explosion venting device of this embodiment, this embodiment also proposes an electrochemical energy storage prefabricated cabin, including the cabin 10 and the above-mentioned explosion venting device for the electrochemical energy storage prefabricated cabin;

The cabin 10 is provided with an installation opening. The frame 1 is located outside the cabin 10 and installed at the installation opening. The door panel 2 is located on the side of the frame 1 away from the cabin 10 .

During normal operation, the door panel of the explosion relief valve is in a closed state under the action of the reset elastic member, ensuring a relatively isolated environment in the cabin. When an abnormality occurs in the battery cells in the prefabricated cabin, the high-temperature hot smoke generated by the reaction in the cabin quickly gathers. At this time, the door panel of the explosion relief valve opens under the action of the air pressure in the cabin, transferring the gas and heat in the cabin out, thereby reducing the pressure and temperature inside the cabin.

In actual design, the return elastic component can use a spring device such as a torsion spring.

In this embodiment, the proposed electrochemical energy storage prefabricated cabin and its explosion venting device have an explosion venting window in the middle of the frame. The door panel is located on one side of the frame and covers the explosion venting window arrangement. One end of the door panel is rotatably installed on the frame. , the connection between the door panel and the frame is provided with a reset elastic member; the shutter is located on the side of the frame away from the door panel and is arranged corresponding to the explosion vent window. Through the above-mentioned optimized design of the explosion venting device for electrochemical energy storage prefabricated cabins, through the cooperation of the door panel and the explosion venting window, the gas channel is opened/closed as the pressure changes to achieve rapid gas discharge, thereby quickly reducing the internal pressure of the prefabricated cabin and preventing The prefabricated cabin combustible gas explodes and resets after the pressure drops. It can be used repeatedly and has low maintenance costs.

In the specific installation method, the shutter 3 and the frame 1 are fixedly connected by bolts to facilitate installation.

Correspondingly, the shutter 3 is located in the cabin, and the shutter 3, the cabin and the frame 1 are fixed by bolts.

In the specific installation method of the door panel, the upper end of the door panel 2 is rotatably connected to the frame 1, and the door panel can be closed under the action of gravity.

In order to ensure the reliability of the frame being installed on the bulkhead of the energy storage prefabricated cabin, in the specific design of the frame, the outer periphery of the frame 1 is provided with a first installation step extending around the explosion vent window. Furthermore, the outer periphery of the shutter 3 is provided with a second installation step 31 extending around the explosion vent window.

In the specific design method of the prefabricated cabin, there are multiple battery placement cavities in the prefabricated cabin, and the side wall of each battery placement cavity is equipped with an explosion relief device.

In actual design, the explosion relief area of the explosion relief valve, that is, the window size, can be designed according to the specific conditions in the cabin. The following explains in detail the principle of the explosion relief valve and the specific calculation process of the explosion relief window through examples.

First, calculate the explosion vent area of the electrochemical energy storage prefabricated cabin in the project:

Assumptions:

In a single battery box (the box contains 16 CATL 271Ah batteries), all the cells experienced thermal runaway and spread to an entire cluster. The flammable gas generated expanded to the battery cluster and started to release pressure (after the battery cells experienced thermal runaway, Thermal diffusion will spread rapidly between the cells in the plug-in box, but it is not easy to spread between the plug-in boxes. It can be determined that the pressure has been released or fire extinguishing measures have been activated before this);

The battery cluster is relatively sealed through fireproof partitions, and the fan system is turned off when a fire occurs. The flammable gas is filled into the space, and leakage in gaps, air ducts, etc. is ignored.

In the actual application process, due to differences in battery core consistency and differences in the timeliness of fire alarm triggering, it is impossible to accurately determine whether the agent has been sprayed when the explosion relief valve is opened. That is to say, there are two situations. The first is that the accumulation of flammable gas causes the explosion valve to open, and the spraying has not been started at this time. In this case, it is enough to calculate the area of the explosion relief valve based on the amount of combustible gas. The second is that the accumulation of combustible gas causes the fire alarm to be triggered. After the agent is sprayed, the space is pressurized. From a superimposed effect, the explosion relief valve will be opened faster and will not affect the minimum value of the explosion relief valve. Therefore, taking the two situations together, the area of the explosion relief valve is calculated based on the amount of combustible gas in the battery core.

Explosion relief valves also come in various shapes, specifications and sizes. Two important parameters that generally need to be considered when calculating the area are the air permeability and the pressure relief after explosion.

1. Calculation of air permeability

According to the requirements of "8.2.8 Temperature Shock" in the national standard GB 38031-2020, the battery pack needs to be placed in an alternating temperature environment of -40~60°C, and the conversion time between the two extreme temperatures is within 30 minutes.

It is assumed here that the entire battery box thermally fails, but the flammable gas will expand to the net air volume of the entire battery cluster of 194.337L.

Among them, the internal volume of the battery cluster is: 950mm×710mm×2010mm=1355.745L;

Battery box volume: 706mm×432mm×238mm=72.588L;

The entire cluster contains 15 battery boxes + 1 high-voltage box. Volume: 61.408L;

Therefore, the net volume of air in the entire battery cluster is 1355.745L-61.408L=194.337L.

According to the national standard requirements, within 30 minutes, when the battery pack heats up from -40°C to 60°C, the expansion of the gas volume is the ventilation required by the explosion relief valve. According to Gay-Lussac's law for ideal gases, when the pressure remains constant, the volume of a certain mass of gas is directly proportional to the thermodynamic temperature. Right now,

V1/T1＝V2/T2＝C(constant) (1);

V3＝V2－V1 (2);

Q＝V3/t×1.5 (3);

In the formula:

V1 is the volume of gas in the box (194.337L) at the initial temperature (-40°C);

T1 is the initial temperature (-40+273)K;

V2 is the volume of gas in the box at 60°C;

T2 is the maximum temperature (60+273)K;

V3 is the volume of gas generated after the temperature inside the box rises;

Q is the air permeability;

t is the temperature rise time, that is, the required exhaust time is 30 minutes;

1.5 is the safety factor.

According to equations (1) to (3), it can be found that the air permeability Q of flammable gas released to the entire battery cluster after a single battery box thermal runaway is equal to 0.0695L/S.

2. Calculation of pressure relief amount

Thermal runaway and thermal diffusion of lithium batteries is a complex failure phenomenon composed of multiple factors. In-depth study of the mechanism of thermal runaway and the phenomenon of battery core explosion is a very tedious project. In order to facilitate quantitative calculations, the following assumptions are made here:

(1) Use CATL 271Ah battery core (volume 174×72×200=2.5056L);

(2) The explosion heat of a single cell spreads to the surrounding 16 cells and fails;

(3) The gas production volume of a single cell is 153.5L (provided by the cell manufacturer), and the gas production volume of 16 cells in a single plug-in box is 2456L; the average time from the safety valve opening to complete thermal runaway (based on three sets of thermal abuse tests) is 45S , so the gas production rate of 16 cells failing at the same time is 54.58L/S;

(4) The exhaust rate of the through hole with a diameter of 10mm (area 78.5mm2) is 6L/s (under 24kPa pressure);

(5) The high temperature generated after the battery core explodes and becomes thermally runaway causes air to expand 10 times the volume of the battery core.

Based on the above assumptions, a whole cluster with 16 cells can be obtained with a volume of 2.5056L×16≈40.0896L.

The amount of gas expansion caused by the explosion of the battery core is 40.0896×10=400.896L.

The gas generated by the thermal runaway of the battery core is 400.896+54.58=455.476L/s, so the pressure release amount of flammable gas from a single battery box to the entire battery cluster is 455.476L/s.

By comparing the air permeability and pressure relief, it was found that the pressure relief was greater. Taking the unfavorable principle into consideration, the pressure relief value was used as a reference.

According to assumption (4), it can be concluded that the required through hole area is

455.476÷6×78.5=5959.1444mm2. If a circular explosion relief valve is used, it can be calculated that the diameter of the explosion relief valve is 87mm.

The principle of the explosion venting device of the electrochemical energy storage prefabricated cabin in this embodiment is as follows:

Under normal working conditions, the air pressure inside and outside the electrochemical energy storage prefabricated cabin is in equilibrium. In this state, the functions of the explosion relief valve and the cabin shell are consistent, which is a daily state. When the pressure inside the prefabricated cabin is much greater than the ambient pressure or the internal pressure reaches the blast value set by the explosion relief valve, it is in an explosion-proof working state. At this time, the internal gas pressure of the prefabricated cabin box will push up the self-vertical plate of the explosion relief valve. Among them, a spring device is provided at the hinge position of the self-vertical plate and the explosion relief valve. The gas will be directly connected to the external environment through barrier-free passages to achieve rapid gas discharge, thereby quickly reducing the internal pressure of the prefabricated cabin and preventing the accumulation and explosion of flammable gases in the prefabricated cabin. This state is an explosion-proof state. When the air pressure inside the prefabricated cabin box drops below the blast value set by the explosion relief valve after exhaust, the self-vertical plate closes and the explosion relief valve immediately returns to normal working condition. One of the most obvious advantages of this explosion relief valve is that it can be used repeatedly, it is not a disposable product, and the use and maintenance costs are very low.

The parameters of this explosion venting device are shown in Table 1 below.

form Mechanical without power supply opening pressure 1000Pa±50Pa closing pressure 850Pa±50Pa ambient temperature -25℃～55℃ Dimensions 360mm*360mm Effective pressure relief area 0.07m2 Cabin reserved dimensions 300mm*300mm

The above are only preferred specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person familiar with the technical field can, within the technical scope disclosed by the present utility model, implement the present utility model according to the present utility model. Novel technical solutions and utility model concepts, including equivalent substitutions or changes, shall be covered by the protection scope of the present utility model.

Claims (8)

1. Explosion venting device for an electrochemical energy storage prefabricated cabin is characterized by comprising the following components: a frame (1), a door plate (2) and a shutter (3);

the middle part of the frame (1) is provided with an explosion venting window, the door plate (2) is positioned at one side of the frame (1) and covers the explosion venting window, one end of the door plate (2) is rotatably arranged on the frame (1), and a reset elastic piece is arranged at the joint of the door plate (2) and the frame (1);

the shutter (3) is positioned on one side of the frame (1) far away from the door plate (2) and is correspondingly arranged with the explosion venting window.

2. The explosion venting device for the electrochemical energy storage prefabricated cabin according to claim 1, wherein the shutter (3) is fixedly connected with the frame (1) through bolts.

3. The explosion venting device for an electrochemical energy storage prefabrication cabin according to claim 1, wherein the upper end of the door plate (2) is rotatably connected with the frame (1).

4. Explosion venting device for an electrochemical energy storage prefabricated compartment according to claim 1, characterized in that the frame (1) is provided with a first mounting step at its periphery extending around the explosion venting window.

5. Explosion venting device for an electrochemical energy storage prefabrication cabin according to claim 4, characterized in that the outer periphery of the louver (3) is provided with a second mounting step (31) extending around the explosion venting window.

6. Electrochemical energy storage prefabricated cabin, characterized by comprising a cabin body (10) and an explosion venting device for an electrochemical energy storage prefabricated cabin according to any one of claims 1-5;

the cabin body (10) is provided with an installation opening, the frame (1) is positioned outside the cabin body (10) and is installed at the installation opening, and the door plate (2) is positioned at one side, far away from the cabin body, of the frame (1).

7. Electrochemical energy storage prefabricated cabin according to claim 6, characterized in that the shutter (3) is located in the cabin (10), the shutter (3), the cabin (10) and the frame (1) being fastened by means of bolts.

8. The electrochemical energy storage prefabricated cabin according to claim 6, wherein a plurality of battery placing cavities are arranged in the prefabricated cabin, and explosion venting devices are arranged on the side walls of each battery placing cavity.