JP3002001B2 - Fire extinguisher in sodium-sulfur battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is sodium - involved in extinguishing HiSo location of a fire in the sulfur batteries, and more particularly sodium - abnormality occurs in the sulfur battery, the chemical reaction of the active material of the anode and cathode in the battery it relates to extinguishing HiSo location of the fire to extinguish the generated fire.

[0002]

2. Description of the Related Art In recent years, research and development of a sodium-sulfur battery operating at 300 to 350.degree. C. has been advanced as a secondary battery for electric vehicles and nighttime power storage. This sodium-sulfur battery has excellent characteristics in both performance and economy.In terms of performance, it has a higher theoretical energy density than a lead-acid battery, has no side effects such as generation of hydrogen or oxygen during charging and discharging, and has a bipolar The utilization rate of active materials is also high. further,
Economically, metallic sodium and sulfur have the advantage of being inexpensive.

The sodium-sulfur battery is rarely used as a single unit. A plurality of the batteries are connected in series, and a plurality of the batteries connected in series are accommodated in a case. Then, by heating the assembled battery to 300 to 350 ° C. in a case, metallic sodium and sulfur serving as active materials are melted, ions of the active material are moved in the molten state, and an electrochemical reaction is performed with each other. In addition, predetermined electric energy is obtained.

[0004]

However, in this conventional sodium-sulfur battery, the solid electrolyte tube inside the battery may be broken for some reason, such as an overcurrent caused by an accidental short-circuit current. At the time of this destruction, the molten metal sodium and the molten sulfur, which have been separated inside and outside by the solid electrolyte tube, come into direct contact, and they mix with each other to cause a chemical reaction. Then, there is a problem that the cover of the battery itself is broken by the reaction heat and a fire occurs in the case containing the battery. It should be noted that the use of water as a fire extinguishing agent in the event of a fire is not appropriate because molten metal sodium reacts violently with water.

The present invention has been made in view of the problems existing in the prior art, and has as its object to quickly and surely extinguish a fire generated in a sodium-sulfur battery. sodium can be - it is to provide an anti HiSo location of a fire in the sulfur battery.

[0006]

In order to achieve the above object, according to the present invention, a tank containing an inert liquid and a particulate fire extinguishing agent, and the inert liquid and the granular fire extinguishing agent in the tank are agitated. A stirring means for producing a slurry fire extinguishing agent, and a pressure feeding means for feeding a slurry fire extinguishing agent from the tank in a case accommodating an assembled battery comprising a sodium-sulfur battery are provided. .

[0007]

In the fire extinguishing system for a sodium-sulfur battery constructed as described above, when an abnormal reaction occurs in the sodium-sulfur battery and a fire occurs in the case, the inert liquid and the particulate fire extinguishing agent are formed in the tank. The slurry is extinguished to produce a fire extinguishing agent. Then, this slurry fire extinguishing agent is supplied under pressure from the tank into the case of the assembled battery, and is filled in the gap between the assembled batteries. When the slurry fire extinguishing agent is filled in this way, the cooling action by the latent heat of evaporation of the inert liquid,
Abnormal reaction of the battery is suppressed by the synergistic effect of the reaction suppression effect of sodium and sulfur by the inert gas generated by the evaporation of the inert liquid, the heat insulation effect by the particulate fire extinguishing agent, and the heat dispersion effect by the granular fire extinguishing agent. At the same time, burning of adjacent healthy batteries can be prevented. Therefore, it is possible to quickly and reliably extinguish a battery fire.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fire extinguishing apparatus for a sodium-sulfur battery embodying the present invention will be described below in detail with reference to the drawings. First, the configuration of the sodium-sulfur battery will be described. As shown in FIGS. 1 to 3, the case 1 is formed in a square box shape having an inner and outer double wall structure.
A heat insulating material 2 is interposed between the inner and outer walls. The mounting table 3 is disposed on the inner bottom of the case 1 via a support member 4 so as to be located at a predetermined distance from the inner bottom of the case 1.

The batteries 5 are arranged upright on the upper surface of the mounting table 3, and a plurality of batteries 5 are connected in series and in parallel. Electric heater 6
Is disposed between the bottom of the case 1 and the mounting table 3, and the electric heater 6 controls the temperature in the case 1 to about 300 to 350.
℃, the metallic sodium and sulfur in the battery 5 are melted. The air supply pipe 7 supplies external air and the like into the case 1. The exhaust pipe 8 is provided adjacent to the supply pipe 7, and the case 1 is connected through the exhaust pipe 8.
The air inside is exhausted to the outside. The temperature in the case 1 is set to about 300 to 35 by the air circulation action by the two pipes 7 and 8 and the temperature control of the electric heater 6.
It is kept at 0 ° C.

A supply pipe 9 is provided at an upper portion of the side wall of the case 1, and a bifurcated supply port 9a is formed at an inner end thereof. Then, the slurry fire extinguishing agent S described below
Is supplied into the case 1 through the supply pipe 9. The discharge pipe 10 is provided at the upper part of the side wall of the case 1 so as to be located at a predetermined distance from the supply pipe 9 to the side, and the discharge port 10 a at the inner end thereof has the same height as the supply port 9 a of the supply pipe 9. Position or slightly lower. When the slurry-type fire extinguishing agent S is supplied to the case 1 in an amount exceeding a predetermined amount, excess slurry-type fire extinguishing agent S is discharged from the discharge pipe 10 to the outside.

Next, the configuration of the fire extinguisher will be described.
As shown in FIGS. 1 and 2, the storage tank 11 is formed in a closed cylindrical shape, in which an inert liquid L and a particulate fire extinguishing agent Sa are stored. The gas cylinder 12 constituting the stirring means is disposed near the storage tank 11 and contains N ₂ gas therein. When the gas valve 13 is opened, the gas introduction pipe 14 extends from the gas cylinder 12.
N ₂ gas is supplied into the storage tank 11 via the storage tank 11, the internal pressure of the storage tank 11 is increased, and the inert liquid L and the particulate fire extinguishing agent Sa in the storage tank 11 are agitated to form a slurry fire extinguishing agent S. Is made.

A liquid feed pipe 15 is connected to a lower portion of the outside of the storage tank 11, and a supply pipe 9 extending from the case 1 of each sodium-sulfur battery is connected in the middle thereof. Pump 16 constituting the pumping means set vignetting on the liquid transfer pipe 15 adjacent to the storage tank 11, by the pump 16 is driven in the open state of the main valve 17, slurry extinguishing agent S is stored Liquid supply pipe 1 from inside tank 11
5 to be pumped. The partition valve 18 is provided on the supply pipe 9, and by opening the partition valve 18, the slurry fire extinguishing agent S is supplied under pressure from the liquid supply pipe 15 to the battery case 1 via the supply pipe 9.

Next, the slurry fire extinguishing agent S will be described in detail. In this embodiment, the mixing ratio of the inert liquid L and the granular fire extinguishing agent Sa in the slurry fire extinguishing agent S is 50 to 50.
80%: set within the range of 50 to 20% by volume. As the inert liquid L, a fluorine-based inert liquid having a nonflammability and a non-conductive property and a boiling point of 250 to 300 ° C. is used. When the fire extinguishing agent S is supplied into the battery case 1 when a fire occurs, the inert liquid L in the slurry S is almost evaporated at 250 to 300 ° C. In addition to exerting the cooling effect, the inert gas generated by the evaporation exerts the effect of suppressing the reaction between sodium and sulfur.

Further, as the particulate fire extinguishing agent Sa, a large number of spherical particles having non-reactivity with an active material of a battery and a product at the time of occurrence of fire and having no hygroscopicity and insulating properties are used. ing. Specifically, it is composed of a ceramic material, sand or the like singly or in combination of plural kinds. In this embodiment, ceramic particles are used. Therefore, when the ceramic particles are described in detail, the particle diameter of the ceramic particles is preferably in the range of 0.05 to 1.0 mm, and in this embodiment, the particle diameter is 0.1 mm. or,
The surfaces of the ceramic grains are formed smooth to reduce the coefficient of friction and facilitate the flow into the gaps between the batteries 5. Further, as the material, feldspar-based ordinary porcelain based on ordinary porcelain, alumina-containing porcelain, cristobalite porcelain, alumina porcelain, zircon porcelain, cordierite porcelain, and the like are suitable.In this embodiment, feldspar-based ordinary porcelain is used. ing. Further, the volume resistivity of these materials slightly decreases with increasing temperature, but at least 1 MΩ-cm
Has the following volume resistivity.

And, even if the metallic sodium in the battery 5 is in a solidified state, hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen sulfide (H ₂ S), hydrogen (H), bromine (Br) , Fluorine (F), chlorine (Cl), sulfur (S),
Since it reacts with mercury (Hg), water (H ₂ O), and the like, it is necessary to select and use ceramic particles that do not contain these substances.

The reaction products generated by the oxidation reaction of metallic sodium and sulfur in the battery 5 include sulfur dioxide (SO ₂ ), sodium hydroxide (NaOH), sodium oxide (Na ₂ O) , and peroxide. Sodium (Na
₂ O _3), sodium sulfide (Na ₂ S O _3), there is carbon disulfide (CS ₂₎ or the like. Further, during the oxidation reaction of the metallic sodium and sulfur, nitrogen in the air is oxidized due to the heat of the oxidation reaction, and nitrogen oxide (NOx) is generated. Therefore, it is necessary to select and use ceramic particles which do not react with these reaction products.

Next, the operation of the fire extinguisher in the sodium-sulfur battery configured as described above will be described. By the way, usually, the inside of the battery case 1 is heated and held at about 300 to 350 ° C. by the electric heater 6, so that metallic sodium and sulfur in a single sodium-sulfur battery constituting the battery 5 are in a molten state. . In this state, when an abnormal reaction or the like occurs in the sodium-sulfur battery and the internal fixed electrolyte tube is broken, the molten metallic sodium in the fixed electrolyte tube directly contacts and mixes with the molten sulfur in the anode container. As a result, the following chemical reaction is performed as a main reaction, and sodium polysulfide, particularly finally, sodium trisulfide is generated.

[0018]

2Na + XS → Na ₂ Sx At this time, a large amount of heat of chemical reaction is generated and the cover of the battery 5 itself is thermally destroyed.
Spills into. As a result, the metallic sodium further reacts with oxygen in the air and the like, and is brought into a high temperature state, and the other batteries 5 are sequentially burned.

When a fire occurs in the case 1 as described above, a fire accident is detected by a heat sensor or a gas sensor (not shown), and the power supply to the electric heater 6 in the case 1 is stopped. Thereafter, the gas valve 13 is opened, and the gas cylinder 1 is opened.
N ₂ gas is supplied into the storage tank 11 from the storage tank 11 via the gas introduction pipe 14. As a result, the internal pressure of the storage tank 11 is increased, and the inert liquid L and the particulate fire extinguishing agent Sa in the storage tank 11 are stirred to form the slurry fire extinguishing agent S.

When the internal pressure of the storage tank 11 reaches a predetermined value, the main valve 17 is opened and the pump 16 is driven, so that the slurry fire extinguishing agent S is discharged from the storage tank 11.
The liquid is sent to the liquid feed pipe 15 from the inside. After that, the partition valve 18 corresponding to the case 1 of the battery in which the fire has occurred is opened, and the fire extinguishing agent S in a slurry state is pressure-fed and supplied from the liquid sending pipe 15 into the case 1 via the supply pipe 9.
Is filled in the gap between the two.

At this time, since the particulate fire extinguishing agent Sa in the slurry extinguishing agent S is mixed and agitated with the inert liquid L to form a slurry having fluidity, the fire extinguishing agent Sa does not stay in the pipes 15 and 9. It is smoothly supplied into the case 1.
Further, as shown in FIG. 3, the supply port 9a of the supply pipe 9 is branched into two branches, so that the slurry-type fire extinguishing agent S can be spread over a wide range in the case 1 from the two-forks supply port 9a. And uniform and rapid filling and supply. Then, as shown in FIG. 3, the case 1 is filled with a predetermined amount of the slurry fire extinguishing agent S, and the liquid level of the slurry fire extinguishing agent S is upward from the upper end of the assembled battery 5 by a predetermined distance (for example, about 10 mm). When the fire extinguishing agent S reaches the position, the slurry extinguishing agent S supplied thereafter is discharged from the discharge pipe 10 to the outside of the case 1.

As described above, the slurry-type fire extinguishing agent S
When filled, the inert liquid L in the slurry fire extinguishing agent S almost evaporates at 250 to 300 ° C., thereby exerting a cooling effect due to the latent heat of evaporation and the inert gas generated with the evaporation. The gas suppresses the reaction between sodium and sulfur. Further, the particulate fire extinguishing agent Sa remains in the case 1 after the evaporation of the inert liquid L, and the batteries 5 are shielded by the granular fire extinguishing agent Sa, thereby exhibiting a heat insulating effect and a heat dispersing effect. Therefore, the cooling effect by the latent heat of evaporation of the inert liquid L, the reaction suppression effect by the inert gas generated when the inert liquid L evaporates, the heat insulating effect by the particulate fire extinguishing agent Sa,
And the synergistic effect of the heat dispersion effect of the granular fire extinguishing agent Sa,
An abnormal reaction of the battery is suppressed, and the fire of the battery can be quickly and surely extinguished by preventing a fire from burning to an adjacent battery.

The present invention is not limited to the structure of the above embodiment. For example, the inert liquid having a boiling point of about 400 ° C., which is the abnormal heating temperature of the battery, may be used.
Selective removal of latent heat of evaporation only for high temperature batteries,
The configuration of each part can be arbitrarily changed and embodied without departing from the gist of the present invention, such as adopting another configuration as the stirring means or the pressure feeding means in the fire extinguisher.

[0024]

According to the present invention, the agitating means can be used in a tank.
Stir the inert liquid and the particulate fire extinguishing agent to make a slurry fire extinguishing agent
And the slurry-type fire extinguishing agent is pumped by battery
Because it is configured to supply pressure inside the case, granular fire extinguishing
The agent Sa is mixed with the inert liquid L and stirred to form a fluid having fluidity.
In the state of a rally, it does not stay in the pipe etc.
It can be supplied smoothly and quickly into the case,
Suppress abnormal reactions and surely extinguish fires in batteries
An excellent effect is achieved.

[0025]

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of a fire extinguishing device in a sodium-sulfur battery embodying the present invention.

FIG. 2 is a perspective view of the fire extinguisher.

FIG. 3 is an enlarged sectional view showing a battery case.

[Explanation of symbols]

1 case, 5 batteries, 9 supply pipe, 11 storage tank, 12 gas cylinder as agitating means, 16 pump as pumping means, S slurry fire extinguishing agent, L inert liquid, Sa granular fire extinguishing agent.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A62C 3/06 H01M 10/39

Claims (1)

(57) [Claims] An assembly comprising a tank containing an inert liquid and a particulate fire extinguishing agent, stirring means for stirring the inert liquid and the granular fire extinguishing agent in the tank to produce a slurry fire extinguishing agent, and a sodium-sulfur battery A fire extinguishing device for a sodium-sulfur battery, comprising: a pumping means for feeding a slurry-type fire extinguishing agent from the tank in a case accommodating the battery.