CN114344772A - A water system fire extinguishing system suitable for electric vehicle power battery and fire extinguishing method thereof - Google Patents

Abstract

The invention discloses a water system fire extinguishing system suitable for an electric automobile power battery and a fire extinguishing method thereof, wherein the system comprises a battery detection unit, a water system fire extinguishing unit and a control unit; the battery detection unit comprises a gas detection probe for detecting the thermal runaway characteristic gas of the power battery module and a temperature detection probe for detecting the surface temperature of the power battery module; the water system fire extinguishing unit comprises a water storage tank and a fire extinguishing nozzle, the fire extinguishing nozzle faces the power battery module, the water storage tank is connected with the fire extinguishing nozzle through a water supply pipeline, and a pump and a control valve are arranged on the water supply pipeline; the control unit controls the working states of the pump and the control valve according to whether the concentration of the thermal runaway characteristic gas exceeds a preset concentration threshold value and whether the temperature of the power battery module exceeds a preset temperature threshold value, so that the fire extinguishing spray head is controlled to spray the module in an abnormal state. The invention can monitor the state of the power battery of the electric automobile, realize effective cooling or fire extinguishing when the power battery is in a thermal runaway state, and reduce the fire loss of the battery module.

Description

A water system fire extinguishing system suitable for electric vehicle power battery and fire extinguishing method thereof

technical field

The invention relates to the technical field of energy storage, in particular to a water-based fire extinguishing system suitable for electric vehicle power batteries and a fire extinguishing method thereof.

Background technique

In recent years, with the proposal of the "new infrastructure" strategy, the construction of domestic electric vehicles and intelligent charging facilities has ushered in a new climax of development. However, the electric vehicle power battery is an energy storage device. Under improper charging conditions, the uncontrolled release of stored energy may be induced, resulting in fire accidents, which seriously affects the personal and property safety of vehicle owners and charging stations. In 2020, the annual production and sales of new energy vehicles in my country will reach 1.366 million and 1.367 million respectively, a year-on-year increase of 7.5% and 10.9%, respectively. The number of new energy vehicles in the country will reach 4.92 million, accounting for 1.75% of the total number of vehicles, compared with 2019. Annual increase of 1.11 million vehicles, an increase of 29.18%. The continuous increase in the number of new energy vehicles has also led to frequent occurrence of safety accidents such as spontaneous combustion and fire of new energy vehicles.

In general, the large-capacity power batteries of new energy vehicles are prone to thermal runaway due to factors such as overcharge, overheating, internal short-circuit, external short-circuit, and mechanical triggering. Moreover, it is difficult to put out a fire after a fire, and the risk of re-ignition is high. With the rapid development of the industry, safety issues have become the key to the development of the new energy vehicle industry, which must be paid attention to by relevant departments and industries. Judging from the state of the vehicle at the time of the fire accident, there were 30 accidents in the stationary state, accounting for about half, followed by accidents during charging, accounting for 28%, and accidents during driving accounted for 23%. Charging safety has always been one of the focuses of the whole society.

Research on power battery fire extinguishing emerges in an endless stream, and the selection of effective fire extinguishing agents and fire extinguishing methods has always been the key to curbing fire accidents. Commonly used fire extinguishing agents are mainly divided into three types: solid, liquid and gas. At present, researchers have mainly studied the effects of fire extinguishing agents including dry powder, water, heptafluoropropane, carbon dioxide, perfluorohexanone, etc. on power battery fires. In terms of water-based fire extinguishing agents, the performance is relatively good.

Existing research on water-based fire extinguishing agents to extinguish battery fires often only adopts the test method of heating until the battery is thermally out of control; for the real battery module environment, the early warning and extinguishing of battery module fires have not yet formed an effective solution; after the battery fire is extinguished There may be a re-ignition situation, and gas extinguishing agents are not effective in suppressing the re-ignition of the battery.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a water-based fire extinguishing system suitable for electric vehicle power batteries and a fire extinguishing method thereof, which can monitor the state of the electric vehicle power battery, realize cooling or fire extinguishing when the power battery is in a thermally runaway state, and can effectively control the battery model. The group fire is effectively extinguished and the fire loss of the battery module is reduced. The technical solution adopted in the present invention is as follows.

In one aspect, the present invention provides a water-based fire extinguishing system suitable for electric vehicle power batteries, comprising: a battery detection unit, a water-based fire-extinguishing unit and a control unit;

The battery detection unit includes a gas detection probe for detecting the characteristic gas of thermal runaway of the power battery module, and a temperature detection probe for detecting the surface temperature of the power battery module;

The water system fire extinguishing unit includes a water storage tank and a fire extinguishing nozzle, the fire extinguishing nozzle is arranged towards the power battery module, the water storage tank and the fire extinguishing nozzle are connected by a water supply pipeline, and a pump and a control valve are arranged on the water supply pipeline;

The signal output ends of the gas detection probe and the temperature detection probe are respectively connected to the control unit; the control unit judges whether the concentration of the thermal runaway characteristic gas exceeds the preset concentration threshold according to the gas concentration signal output by the gas detection probe, and, according to the output of the temperature detection probe The temperature signal of the power battery module judges whether the temperature of the power battery module exceeds the preset temperature threshold. If the judgment result is that the concentration exceeds the preset concentration threshold and the temperature exceeds the temperature threshold, the control valve on the water supply pipeline is controlled to open and the pump starts to run.

Optionally, the power battery module includes a casing, the casing includes a top cover, and the fire extinguishing nozzle is arranged in the casing at a height of 3 cm from the top cover.

Optionally, the water system fire extinguishing system further includes an alarm unit, and the control unit controls the alarm unit to output an alarm signal when it is determined that the concentration exceeds the preset concentration threshold and/or the temperature exceeds the temperature threshold. The alarm unit can adopt the form of sound and light alarm.

Optionally, at least two temperature detection probes are provided, which are respectively facing different side surfaces of the power battery module.

Optionally, the temperature detection probe adopts an infrared probe.

Optionally, the gas detected by the gas detection probe is a composite gas, and the composite gas includes hydrogen and carbon monoxide.

In the second aspect, the present invention also provides the fire extinguishing method for the water-based fire extinguishing system of the electric vehicle power battery according to the first aspect, which is executed by the control unit, and the method includes:

Obtain the concentration information of the characteristic gas of thermal runaway detected by the gas detection probe, and the temperature information of the power battery module detected by the temperature detection probe;

Determine whether the concentration of the thermal runaway characteristic gas exceeds the preset concentration threshold according to the gas concentration signal, and determine whether the temperature of the power battery module exceeds the preset temperature threshold according to the temperature information;

When the gas concentration exceeds the preset concentration threshold and the temperature of the power battery module exceeds the preset temperature threshold, the control valve on the water supply pipeline is controlled to open and the pump starts to run to spray the power battery module.

Optionally, when judging the gas concentration and temperature, first judge whether the concentration information of the characteristic gas of thermal runaway is beneficial to the preset concentration threshold. If it does not exceed the preset concentration threshold, it is deemed that fire extinguishing is not required. If it exceeds, the temperature of the power battery module is judged. Whether it exceeds the preset temperature threshold, if the temperature exceeds the preset temperature threshold, it is deemed that fire extinguishing is required.

Optionally, when spraying the power battery module, control the control valve and the pump to open, so that the fire extinguishing nozzle sprays the power battery module for 10 minutes, obtain the temperature information again, and determine whether the temperature reaches below the preset safety threshold, If not, continue spraying until the temperature after spraying reaches below the preset safety threshold, stop spraying, and continue to monitor the power battery module. The pump can be a high-pressure pump, and the fire-extinguishing nozzle can be a spray-type nozzle, so that the fire-extinguishing water agent can spray the power battery module in the form of high-pressure fine water mist to extinguish and cool down the power battery module.

Optionally, the fire extinguishing method further includes: when it is determined that the concentration exceeds a preset concentration threshold and/or the temperature exceeds the temperature threshold, controlling a preset alarm unit to output an alarm signal.

beneficial effect

Aiming at the need for early warning of thermal runaway of electric vehicle power batteries, the invention proposes for the first time to combine gas on-line monitoring and infrared on-line monitoring, and monitor the thermal runaway state of the battery module according to the actual thermal runaway characteristics of the battery. When the thermal runaway characteristics (including gas and temperature) meet the set conditions, the fire extinguishing nozzle is automatically controlled to spray fire or cool down the monitored power battery module. The fire extinguishing device provided by the present invention can accurately extinguish the fire of the battery module and prevent the re-ignition, thereby realizing the functions of early warning, fire-extinguishing and anti-re-ignition of the electric vehicle power battery thermal runaway.

Description of drawings

FIG. 1 is a schematic structural diagram of an embodiment of a water-based fire extinguishing system suitable for electric vehicle power batteries according to the present invention;

FIG. 2 is a schematic flowchart of an embodiment of a fire extinguishing method executed by the control unit in the system of Embodiment 1. FIG.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solutions of the present invention more clearly, and cannot be used to limit the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "center", "portrait", "horizontal", "top", "bottom", "front", "rear", "left", "right", " The orientation or positional relationship indicated by vertical, horizontal, top, bottom, inner, outer, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and The description is simplified rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. In addition, the terms "first", "second", etc. are used for descriptive purposes only, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first", "second", etc., may expressly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

Example 1

This embodiment introduces a water-based fire extinguishing system suitable for electric vehicle power batteries. Referring to FIG. 1 , the water-based fire-extinguishing system includes a battery detection unit, a water-based fire-extinguishing unit and a control unit.

The battery detection unit includes a gas detection probe and 2 temperature detection probes 5. The 2 temperature detection probes are respectively set towards the front and side of the power battery module. The gas detection probe 1 is set in the casing of the power battery module and is used to detect the power Thermal runaway characteristic gases of battery modules. The temperature detection probe 5 adopts an infrared probe, such as a line temperature measurement thermal imager; the gas detection probe 1 adopts a composite gas detector, and the detected gas is a composite gas. According to the characteristics of the power battery module when it is thermally out of control, the composite gas includes hydrogen. and carbon monoxide.

The water-based fire extinguishing unit includes a water storage tank 8 and a fire extinguishing nozzle 11. The fire extinguishing nozzle 11 is disposed toward the power battery module, preferably 3 cm below the top cover of the power battery module housing. The water storage tank 8 and the fire extinguishing nozzle 11 are connected through a water supply pipeline 10 , and a high pressure pump 9 and a control valve 7 are arranged on the water supply pipeline 10 .

The signal output ends of the gas detection probe 1 and the temperature detection probe 5 are respectively connected to the control unit; the control unit judges whether the concentration of the thermal runaway characteristic gas exceeds the preset concentration threshold of 100 ppm according to the gas concentration signal output by the gas detection probe 1, and according to the temperature detection probe 5. The output temperature signal judges whether the temperature of the power battery module exceeds the preset temperature threshold of 60 ^° C, and if the judgment result is that the concentration exceeds the preset concentration threshold and the temperature exceeds the temperature threshold, the control valve 7 on the water supply pipeline 10 is controlled to open , the pump 9 starts to run.

The water system fire extinguishing system of this embodiment also includes an alarm unit. When the control unit determines that the concentration exceeds the preset concentration threshold or the temperature exceeds the temperature threshold, the control unit outputs an alarm signal. The alarm unit can be realized by using the alarm light 4 .

Example 2

This embodiment introduces the fire extinguishing method of the water system fire extinguishing system in Example 1, which is executed by the control unit, including:

Obtain the concentration information of the characteristic gas of thermal runaway detected by the gas detection probe, and the temperature information of the power battery module detected by the temperature detection probe;

Determine whether the concentration of the thermal runaway characteristic gas exceeds the preset concentration threshold according to the gas concentration signal, and determine whether the temperature of the power battery module exceeds the preset temperature threshold according to the temperature information;

When the gas concentration exceeds the preset concentration threshold and the temperature of the power battery module exceeds the preset temperature threshold, the control valve on the water supply pipeline is controlled to open and the pump starts to run to spray the power battery module.

Referring to FIG. 2, and in combination with the architecture of the water system fire extinguishing system in Embodiment 1, the specific steps of the fire extinguishing method of this embodiment are as follows:

S1, the control unit acquires the concentration information of the thermal runaway characteristic gas detected by the gas detection probe 1, and starts a gas threshold judgment program: according to the gas concentration signal, it is judged whether the concentration of the thermal runaway characteristic gas exceeds a preset concentration threshold of 100 ppm, and when the gas concentration If the gas concentration threshold is not exceeded, it is deemed that there is no need to extinguish the fire, and the concentration information of the characteristic gas of thermal runaway is continued to be monitored; if the gas concentration threshold is exceeded, the temperature information of the power battery module detected by the temperature detection probe 5 is obtained;

S2, the control unit starts the temperature threshold judgment program: according to the temperature information, it is judged whether the surface temperature of the power battery module exceeds the preset temperature threshold of 60 ^° C. If the temperature does not exceed the preset temperature threshold, it is deemed that there is no need to put out the fire, and the thermal runaway monitoring is continued. Concentration information of characteristic gas; if the temperature exceeds the preset temperature threshold (at this time, the gas concentration still exceeds the preset concentration threshold), the control valve 7 on the water supply pipeline 10 is controlled to open, and the pump 9 starts to run, so as to control the power battery module. Do a spray.

When spraying the power battery module, control the control valve 7 and the pump 9 to open, so that the fire extinguishing nozzle 11 sprays the power battery module for 10 minutes, obtains the temperature information again, and judges whether the temperature is below the preset safety threshold. If the temperature is not reached, continue spraying until the temperature after spraying reaches the preset safety threshold below 50°C, stop spraying, and continue to monitor the power battery module. The pump 9 can be a high-pressure pump, and the fire-extinguishing nozzle 11 is a spray-type nozzle, so that the fire-extinguishing water agent can spray the power battery module in the form of 5MPa high-pressure water mist to extinguish fire and cool down the power battery module.

While controlling the pump and the control valve to start the fire extinguishing of the water system, the present embodiment can also output an alarm signal through a preset alarm unit. In order to adapt to early warning in various situations, in this embodiment, different alarm output forms can be set separately for the situations where a single temperature exceeds the threshold value, a single gas concentration exceeds the threshold value, and both the temperature and the gas concentration exceed the threshold value, such as setting alarm lights of different colors. , or output the corresponding alarm status information through the man-machine interface interface.

In summary, the above embodiments can accurately extinguish the fire of the battery module and prevent the re-ignition, thereby realizing the functions of early warning, fire-extinguishing and anti-re-ignition of the electric vehicle power battery thermal runaway.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative rather than restrictive. Under the inspiration of the present invention, without departing from the scope of protection of the present invention and the claims, many forms can be made, which all belong to the protection of the present invention.

Claims (10)

1. A water-based fire suppression system suitable for use in an electric vehicle power cell, comprising: a battery detection unit, a water system fire extinguishing unit and a control unit;

the battery detection unit comprises a gas detection probe for detecting the thermal runaway characteristic gas of the power battery module and a temperature detection probe for detecting the surface temperature of the power battery module;

the water system fire extinguishing unit comprises a water storage tank and a fire extinguishing nozzle, the fire extinguishing nozzle faces the power battery module, the water storage tank is connected with the fire extinguishing nozzle through a water supply pipeline, and a pump and a control valve are arranged on the water supply pipeline;

the signal output ends of the gas detection probe and the temperature detection probe are respectively connected with the control unit; the control unit judges whether the concentration of the thermal runaway characteristic gas exceeds a preset concentration threshold value or not according to a gas concentration signal output by the gas detection probe, judges whether the temperature of the power battery module exceeds a preset temperature threshold value or not according to a temperature signal output by the temperature detection probe, and controls a control valve on a water supply pipeline to be opened and a pump to start running if the concentration exceeds the preset concentration threshold value and the temperature exceeds the temperature threshold value according to a judgment result.

2. The water-based fire suppression system for electric vehicle power batteries according to claim 1, wherein: the power battery module includes the casing, and the casing includes the top cap, the shower nozzle of putting out a fire locates in the casing apart from the 3cm high department of top cap.

3. The water-based fire suppression system for electric vehicle power batteries according to claim 1, wherein: the water system fire extinguishing system also comprises an alarm unit, and the control unit controls the alarm unit to output an alarm signal when judging that the obtained concentration exceeds a preset concentration threshold or the temperature exceeds a temperature threshold; the alarm unit adopts an acousto-optic alarm form.

4. The water-based fire suppression system for electric vehicle power batteries according to claim 1, wherein: the temperature detection probe sets up 2 at least, respectively towards the different side surfaces of power battery module.

5. The water-based fire suppression system for electric vehicle power batteries according to claim 4, wherein: the temperature detection probe adopts an infrared probe.

6. The water-based fire suppression system for electric vehicle power batteries according to claim 1, wherein: the gas detected by the gas detection probe is a composite gas, and the composite gas comprises hydrogen and carbon monoxide.

7. A fire extinguishing method of the water-based fire extinguishing system for electric vehicle power battery according to any one of claims 1 to 6, performed by a control unit, the method comprising:

acquiring concentration information of the thermal runaway characteristic gas detected by a gas detection probe and temperature information of the power battery module detected by a temperature detection probe;

judging whether the concentration of the thermal runaway characteristic gas exceeds a preset concentration threshold value or not according to the gas concentration signal, and judging whether the temperature of the power battery module exceeds a preset temperature threshold value or not according to the temperature information;

when the gas concentration exceeds a preset concentration threshold value and the temperature of the power battery module exceeds a preset temperature threshold value, the control valve on the water supply pipeline is controlled to be opened, and the pump starts to operate so as to spray the power battery module.

8. The fire extinguishing method of claim 7, wherein the fire extinguishing method is performed by a fire extinguishing system for a water-based fire extinguishing system for a power battery of an electric vehicle, the fire extinguishing method comprising: when carrying out gas concentration judgement and temperature judgement, at first judge that whether the concentration information of thermal runaway characteristic gas benefits predetermines the concentration threshold value, if do not surpass then regard as not needing to put out a fire, if surpass then judge that the temperature of power battery module is whether surpass and predetermine the temperature threshold value, if the temperature surpasss and predetermine the temperature threshold value, then regard as needs to put out a fire.

9. The fire extinguishing method of claim 7, wherein the fire extinguishing method is performed by a fire extinguishing system for a water-based fire extinguishing system for a power battery of an electric vehicle, the fire extinguishing method comprising: when spraying the power battery module, control valve and pump are opened for the shower nozzle of putting out a fire sprays 10 minutes to the power battery module, reacquires temperature information, judges whether the temperature reaches below the preset safety threshold, if not reach then continue to spray, reach below the preset safety threshold until the temperature after spraying, stop spraying, and continue the monitoring to the power battery module.

10. The fire extinguishing method of claim 7, wherein the fire extinguishing method is performed by a fire extinguishing system for a water-based fire extinguishing system for a power battery of an electric vehicle, the fire extinguishing method comprising: further comprising: and when the concentration exceeds a preset concentration threshold value or the temperature exceeds a temperature threshold value, controlling a preset alarm unit to output an alarm signal.

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