JPH09298070A - Module type secondary battery, and module type secondary battery unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change output of a module type secondary battery, and change discharge time of it by using a cooling device in which heat radiation quantity is decided in accordance with temperature change of the module type secondary battery. SOLUTION: For a module type NaS battery, plural NaS batteries 5 are contained in a heat insulated container 3 to compose a module. In this case, a changeable conductance type heat pipe 15 of which heating part is embedded in a heat collecting bottom plate 10 at a bottom part of the heat insulated container 3 is provided, and the whole body of the module type NaS battery is heat-radiated and cooled by the changeable conductance type heat pipe 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a module-type secondary battery and a module-type secondary battery thereof, which are used as a module in which a plurality of single secondary batteries such as sodium-sulfur batteries (hereinafter referred to as NaS batteries) are integrally housed. A module-type secondary battery unit containing a plurality of modules in a casing, the module-type secondary battery including a cooling device for cooling the module-type secondary battery to adjust the temperature of the module-type secondary battery, and a module Type secondary battery unit.

[0002]

Demand for electric power as electric energy is increasing year by year because it is clean and environmentally friendly. Since the large-scale power source constructed with such an increase in demand is constructed at a point distant from the demand site, reducing the cost of electricity transportation realizes an efficient power supply system. Has become extremely important above.

On the other hand, the demand for electric power has increased remarkably for commercial use and household use as compared with industrial use, and there is a large difference in the demand for electric power between daytime and nighttime. Since the power supply system is designed according to the maximum power consumption during the day despite the remarkable difference in the power demand, the efficiency of the entire supply system deteriorates and the economy is poor.

Therefore, an electric power storage system has been proposed in order to level the electric power demand (load) and reduce the transportation cost. This electric power storage system stores electric power at night when there is a margin of electric power supply, and uses the stored electric power when the daytime demand for electric power is high to level the load and reduce the transportation cost. , Is attracting attention.

As such a power storage system, there is a system having a secondary battery for storing (charging) and discharging (discharging) electric energy.

The secondary battery is a sodium-sulfur battery (Na
S battery), zinc-chlorine battery, zinc-bromine battery, redox flow battery, lead acid battery, etc.
It has features (see FIG. 23). In addition, a lithium battery using lithium as a positive electrode active material or a negative electrode active material as a secondary battery has been widely spread in recent years. In particular, FIG. 24 shows the performance and characteristics of the molten salt secondary battery using lithium as the negative electrode active material.

In the above-mentioned secondary battery, when a loss such as a reaction loss or an electric resistance loss occurs, this loss becomes heat and raises the temperature of the battery body. Battery temperature rise is
In many cases, the battery reaction speed is accelerated to reduce loss, but on the other hand, the increase in battery temperature causes a decrease in battery life (life of charge / discharge cycles, life of service life).

The decrease in battery life due to the increase in battery temperature appears regardless of the difference in operating temperature of each secondary battery (see FIGS. 23 and 24). For example, FIG. 25 shows the relationship between the battery temperature and the number of lives (the number of times of charging / discharging) of a lead-acid battery that operates at room temperature, and FIG. 26 shows the relationship between the battery temperature and the life (use life). From FIG. 25 and FIG. 26, it can be seen that as the battery temperature rises, the number of charge / discharge cycles and the service life of the battery decrease.

Therefore, in order to maintain the life of the secondary battery, it is necessary to maintain the battery temperature of the secondary battery at an appropriate temperature. For this reason, the secondary battery controls the temperature of the battery temperature.For this temperature control, a method is known in which the maximum battery temperature is controlled and controlled, and the battery temperature before the start of discharge is controlled and controlled to a constant temperature. Has been.

The temperature control system of the secondary battery described above is
The S battery will be described below as an example.

First, the structure of the NaS battery will be described. FIG. 27 is a diagram showing the structure of a NaS battery (single battery). According to FIG. 27, the unit cell has a cylindrical structure,
Sodium electrode (negative electrode) 100, sulfur electrode (positive electrode) from the center
101 and a beta alumina tube (electrolyte) 102 in this order. In addition, inside the beta alumina tube 102,
A metal container called a safety pipe 103 is stored.

The NaS battery performs the following series of operations during discharging and charging. That is, during discharge, sodium in the sodium electrode 100 emits electrons to the external circuit to become sodium ions, and the sodium ions pass through the beta-alumina tube 102 and reach the sulfur electrode 10.
It moves to the 2 side and reacts with the sulfur of the sulfur electrode 102 and the electrons sent from the external circuit to become sodium polysulfide. Further, during charging, sodium polysulfide is divided into sodium ions, sulfur and electrons, and the sodium ions therein move through the beta-alumina tube 102 to the sodium electrode 100 side to remove the electrons supplied from the external power source. Receive and return to sodium.

The NaS battery that performs the above-described discharging / charging operation is a high-temperature operating battery (300 ° C. to 3 ° C. as shown in FIG.
Since it is 50 ° C.), the single cells are assembled and housed in a heat insulating container and used as a module. FIG. 28 is a diagram showing the module structure.

According to FIG. 28, the modular structure of NaS
The battery (NaS module battery) 110 is a box-shaped container with a lid composed of a vacuum container wall (a lid is a vacuum heat insulating container (top) 1
11, the container body has a vacuum heat insulation container (lower) 112), and the battery storage container 1 is provided inside the vacuum heat insulation container (lower) 112.
13 is provided. This battery storage container 113 is made of an aluminum heat collecting bottom plate 1 at the bottom of the vacuum heat insulating container (lower) 112.
14 is installed on the inside of which a plurality of unit cells 115 are installed.
Are housed upright. The plurality of unit cells 115 are
It is fixed by filled and fixed sand (filled sand) 116.

A side heater 117 and a bottom heater 118 are provided on the side wall and the bottom wall of the vacuum heat insulating container (lower) 112, respectively.
The side heater 117 and the bottom heater 11 are provided.
8 controls the temperature inside the module. A conductor group including signal lines, heater conductors, etc. is taken out to the outside as a main pole 120 through a through hole 119 in the side wall of the vacuum heat insulating container (lower).

Next, the temperature control system for the NaS module battery described above will be described.

The heat generated from the NaS module battery is determined by the resistance loss heat generation and the entropy loss heat generation, and changes depending on the value of the energizing current during charging / discharging. And the calorific value is
It becomes high at the time of discharging because the entropy loss heat generation is added to the resistance loss heat generation, but it is small at the time of charging because the entropy loss heat generation is subtracted.

The lower the operating temperature of the battery is,
The resistance loss increases, the amount of heat generation increases, and the efficiency deteriorates (the battery reaction deteriorates). On the other hand, at high temperatures, the resistance loss decreases, but the internal resistance tends to increase over time due to deterioration over time, and the battery life decreases (see FIG. 26 above).
Therefore, a normal NaS module battery has an appropriate operating temperature range, and the operating temperature range is 30% as described above.
It is about 0 ° C to 350 ° C.

That is, in the temperature control of the NaS module battery, it is important to set the temperature before the discharge of the NaS module battery to 300 ° C. and the maximum temperature of the NaS module battery that rises during discharging to 350 ° C. or less. Is.

As described above, in order to control the temperature range of the NaS module battery to 300 ° C. to 350 ° C., it is necessary to dissipate (cool) the heat generated from inside the NaS module battery. Conventionally, highly reliable natural cooling has been adopted for cooling NaS module batteries.
= [Heat storage of battery itself (temperature rise of battery)] + [heat radiation amount (cooling amount) from the surface of the heat insulating container].

FIG. 29 shows the transition of the battery temperature of the NaS module battery by the natural cooling method described above.
Referring to 9, the actual NaS module battery 110
A method of managing and controlling the maximum battery temperature and the temperature before the start of discharge in the above will be described below.

(1) Control of maximum battery temperature When the NaS module battery 110 starts discharging, the temperature of the NaS battery at the temperature Tsa before discharge (for example, 300 ° C.) gradually rises according to the discharge output of the battery. Go (time t1 to t2).

However, the NaS module battery 11
The maximum temperature Tma of 0 is a predetermined control value (Tmax: 35
Vacuum insulation container (upper) 11
1 and the heat radiation amount from the vacuum heat insulating container (bottom) 112 are adjusted. As a specific adjusting method, in designing the vacuum heat insulating container (upper) 111 and the vacuum heat insulating container (lower) 112, the vacuum degree of the vacuum container wall of the container is adjusted, and the thickness of the vacuum container wall is adjusted. Has obtained proper heat dissipation performance.
Therefore, at the end of discharge (time t2), Na
The temperature Tma of the S module battery 110 is "Tma <Tmax
It has become. In general, the heat radiation performance of the vacuum heat insulation container is adjusted so that the heat radiation amount from the battery and the heat storage amount to the battery itself are substantially equal to each other.

(2) Management of temperature before starting heat radiation After the end of discharge (at the end, NaS battery temperature Tma), the vacuum heat insulating container (upper) 111 and the vacuum heat insulating container (lower) 112.
The temperature of the NaS module battery 110 gradually decreases from the start of charging (time t3) to the end of charging (time t4) of the NaS module battery due to natural heat dissipation from the wall of the vacuum container. Go (there is a slight heat generation during charging, so the temperature drop rate is slightly worse).

Then, the temperature of the NaS module battery 110 is lowered to near the temperature before the start of discharge (control value Tsa), and when the temperature is lowered below the control value Tsa by a predetermined temperature (time t5), the side surface provided inside the vacuum container. The heater 117 and the bottom heater 118 are driven to finely adjust the temperature of the NaS module battery 110 to the control value Tsa. Therefore, the difference Δt between the temperatures Tsa ′ and Tsa at the start of the next discharge (t6) is Δt = 0 ° C.

As described above, according to the temperature control system of the NaS module battery, the degree of vacuum and the thickness of the vacuum vessel wall of the vacuum heat insulating vessel are adjusted in advance to set an appropriate amount of natural heat radiation, This is a method of controlling the temperature of the NaS battery by the amount of heat radiation and the heater.

It is also possible to stack the NaS batteries having the above-mentioned module structure in a plurality of stages (up to about 10 stages) and use them as one unit. FIG. 30 (a) is a front view schematically showing a module battery unit 131 in which NaS module batteries 130 are stacked in three stages (a side surface on the lateral direction side of the module is a front surface), and FIG. It is a side view which shows the module battery unit 131 schematically.

According to FIGS. 30 (a) and 30 (b), the module battery unit 131 has cooling air in the casing 13.
Type that naturally circulates in 2 (Natural circulation type Fig. 30
(See (a)) and a type in which cooling air is forcibly circulated in the casing 132 by a blower or the like (forced circulation type). For example, the cooling air sent into the casing 131 of the unit 131 by the natural circulation method flows through the gaps between the modules 132 as passages.

On the other hand, each unit cell 1 in the battery storage container 113
Heat flow is released from 15 through the vacuum heat insulation container (upper) 111 and the vacuum heat insulation container (lower) 112 (see the alternate long and short dash line in FIG. 27), but the heat flow thus radiated is cooled between the modules 130. It is cooled by air.

After cooling the heat flow discharged from the module battery 130 in this way, the cooling air flows out to the outside of the casing 132.

[0031]

However, the above-mentioned temperature control system for the NaS module battery has the following problems.

(1) It is difficult to change the operating output and discharge time of the NaS module battery. In the temperature management method described above, the heat radiation performance of the vacuum heat insulating container is adjusted in advance so that the sum of the heat radiation amount from the NaS module battery and the heat storage amount to the battery itself substantially matches the heat radiation amount from the battery. That is,
This is a temperature management method based on a preset amount of heat radiation on the assumption that the amount of heat generated from the battery does not change significantly (the amount of heat radiation is constant). Therefore, when the NaS battery output (output capacity) and the discharge time are changed so as to change the heat generation amount, the temperature rise curve at the time of discharge (time t
1 to t2) will be changed. For example, as shown by the phantom line in FIG. 29, when the NaS battery output capacity is increased,
The temperature rise curve during discharge rises rapidly (C1), and the module battery temperature exceeds the maximum battery temperature immediately after the start of discharge. Further, as can be seen from FIG. 29, the temperature rise curve at the time of discharge is the discharge time (t1 to t2).
) Is a proportional curve that reaches the maximum battery temperature, so if the discharge time is increased (t2 is changed to t2 '), the temperature rise curve will be extended accordingly (broken line C).
2) Similarly, the module battery temperature will exceed the maximum battery temperature. Also, since the temperature drop curve when the module battery temperature is lowered is a proportional curve, if the standby time, charging time, etc. increase more than necessary as the discharge time increases, the temperature drop curve drops sharply as it does when rising. In addition, the temperature drop curve is extended, and the module battery temperature may be significantly lower than the temperature before the start of discharge. That is, in the conventional temperature control method, when the operation output and discharge time of the NaS module battery are changed, it becomes very difficult to maintain the maximum battery temperature and the temperature before discharge start (control value) of the module battery, The operation output and the discharge time cannot be changed, which impedes the improvement of the practicality of the NaS module battery.

(2) It is necessary to control the degree of vacuum of the vacuum insulation container.

In order to secure a predetermined amount of heat radiation adjusted in advance, it is necessary to maintain and secure the vacuum degree of the heat insulating container,
It was a problem from a maintenance-free perspective.

(3) The energy efficiency is lowered due to the increase of electric power supplied to the heater. N for power storage
Although the aS module battery is expected to be used for more than 10 years, as shown in FIG. 25, the heat generation amount of the battery increases due to deterioration of charge / discharge efficiency over time. Therefore, the vacuum degree of the vacuum insulation container should be adjusted. It is necessary to increase heat dissipation performance and reduce the maximum battery temperature. For this reason, the battery temperature drop rate after the end of discharge increased, the amount of electric power supplied to the heater for maintaining the temperature before start of discharge increased, and the energy efficiency of the NaS module battery decreased.

(4) A vacuum heat insulating container is required. In the current vacuum insulation container, as can be seen from the flow of heat flow indicated by the arrow in FIG. 31, heat is radiated from the side wall surface and the upper and lower wall surfaces, and further radiated from the mating portion of the lid structure. As described above, since the NaS module battery operates at high temperature,
In order to prevent the temperature inside the battery from dropping extremely, a structure is used in which the heat insulating wall is evacuated to reduce the total amount of heat radiation. However, since this vacuum insulation container needs to be completely sealed to maintain a predetermined degree of vacuum for a long period of time, an advanced container manufacturing technique is required, resulting in high cost.

(5) The temperature distribution in the horizontal direction in the NaS module battery is large. Dissipation of heat from a group of cells (heat flow)
Is discharged to the outside from the upper and lower wall surfaces along the horizontal direction of the container through the side wall surfaces, so that the temperature distribution as shown in FIG. 31 occurs along the horizontal direction inside the NaS module battery. .

The present invention has been made in consideration of the above circumstances, and uses a cooling device in which the amount of heat radiation (cooling amount) is determined according to the temperature change of a secondary battery having a module structure (module type secondary battery). Thus, the first object is to make it possible to change the output and the discharge time of the module type secondary battery.

Further, the present invention provides a maintenance-free module-type secondary battery which is low in cost and does not require management of the degree of vacuum by making the heat insulating container of the module-type secondary battery non-vacuum. Its second purpose.

Further, according to the present invention, the heat is not radiated through the side wall surface of the heat insulating container constituting the module type secondary battery, but is radiated through the bottom portion (lower wall surface) of the container, whereby the module type secondary battery is radiated. A third object is to make the temperature distribution in the battery in the horizontal direction substantially constant.

[0041]

In order to solve the above-mentioned problems, according to the present invention, as described in claims 1 to 3,
Multiple secondary batteries alone (eg sodium-sulfur battery)
In a module-type secondary battery in which a module is housed in a container, a cooling device that has a heat radiation amount according to a temperature change of the module-type secondary battery and radiatively cools the entire module-type secondary battery ( For example, a variable conductance type heat pipe (in which a heat working medium and a non-condensable gas are enclosed) is provided.

According to the invention described in claims 4 to 6,
The heat pipe is connected to a heating unit that encloses the heat working medium and is heated from the outside, a condensing unit that performs a condensing action based on steam generated by heating the heat working medium by the heating unit, and a condensing unit. The non-condensable gas is filled in the non-condensable gas, and the non-condensable gas sealed in the gas reservoir is retained at a predetermined position in the condenser. Further, the heat pipe is arranged such that the heating unit is disposed at a bottom portion of the container, and the pipe including the condensing unit is bent so as to be substantially orthogonal to the heating unit and is substantially formed on at least one side surface of the container. It is an L-shaped structure arranged in parallel.

According to the invention described in claims 7 to 8,
Radiating fins are provided over the entire area along the axial direction of the condensing part, and the radiating fins are formed in a taper shape from a predetermined portion along the axial direction of the condensing part toward the end on the heating part side. There is. Further, according to the invention described in claim 9, a slit is provided to the radiating fin perpendicularly to the axial direction of the condensing portion, and the area of the radiating fin is divided by the slit along the axial direction. ing.

According to the invention described in claims 10 to 11, at least one wall surface of the container is a non-vacuum adiabatic wall surface containing a gas under normal pressure,
One wall surface is a side surface adjacent to the condensing part. Further, as described in claim 12, the upper surface of the container is omitted, and the upper surface portion is constituted by a heat insulating material and a partition lid.

According to the thirteenth aspect of the present invention, the noncondensable gas and the vapor of the heat working medium are adjusted by adjusting the pressure of the noncondensable gas enclosed in the gas reservoir and retained in the condenser. By setting the boundary surface of the heat pipe to a predetermined position, the operation start temperature of the heat pipe is set to a predetermined temperature within the operation temperature range of the module-type secondary battery.

According to the fourteenth aspect of the present invention, the heat radiation amount becomes an amount based on the dead zone of the heat pipe when the temperature of the heating portion is lower than the operation start temperature, and the temperature of the heating portion is When the temperature rises above the operation start temperature, the temperature is set to increase in accordance with the increase in the boundary surface in the condensing part due to the temperature increase.

According to the invention described in claim 15, when the temperature of the heating portion drops from the maximum temperature, if the temperature is equal to or higher than the operation starting temperature, the amount of heat radiation is accompanied by the temperature drop. It is set so as to decrease in accordance with the drop of the boundary surface in the condensing section, and when the temperature of the heating section drops below the operation start temperature, it becomes an amount based on the dead zone of the heat pipe. Is set to.

According to the sixteenth aspect of the present invention, the temperature of the module-type secondary battery is such that the amount of heat radiation is until the temperature of the secondary battery reaches from the temperature before discharge start to the operation start temperature. Since the amount is based on the dead zone of the heat pipe, the temperature rises linearly, and in the range where the temperature of the secondary battery exceeds the operation start temperature, the heat radiation amount is increased in accordance with the increase in the condensing portion of the boundary surface. As it increases, it is set to draw a gentle parabola and rise.

According to the invention as set forth in claim 17, the temperature of the module type secondary battery is such that the heat radiation amount is the boundary until the temperature of the secondary battery reaches the operation starting temperature from the maximum temperature. As the temperature of the secondary battery exceeds the operation starting temperature, the amount of heat dissipation is based on the dead zone of the heat pipe. Therefore, it is set to draw a gentle parabola and descend.

According to the eighteenth aspect of the present invention, a unit is constituted by housing a plurality of the module type secondary batteries described in the above-mentioned respective claims in a casing.

According to the nineteenth aspect of the present invention, the module-type secondary batteries are housed in the casing in a close-packed manner, and between the adjacent module-type secondary batteries and between the casing and each module-type secondary battery. Insulation material is buried between and.

According to the invention as set forth in claim 20, a plurality of module-type secondary batteries according to claim 5 or 6 are housed in a casing to form a unit, and the module-type secondary battery in the casing is formed. The container of the battery is formed by a hexagonal columnar container whose top and bottom surfaces are represented by hexagons, and the plurality of heat pipes are arranged so that their heat radiation portions are substantially parallel to the side surfaces of the hexagonal columnar container. .

According to the twenty-first aspect of the present invention, the side surfaces of the hexagonal columnar containers of the module-type secondary batteries adjacent to each other in the heat-dissipating portion of the heat pipe are located between the hexagonal columnar containers of the adjacent module-type secondary batteries. It is a side surface other than the contacting side surface, and the module-type secondary batteries formed of the hexagonal columnar container are arranged in a closest packing manner.

According to the invention described in claim 22, a plurality of module type secondary batteries according to claim 6 are accommodated in a casing to form a unit, and the module type secondary battery formed by the hexagonal columnar container is formed. A plurality of secondary batteries are arranged adjacent to each other so that a space is formed in the center of each secondary battery, and the heat dissipation portions of the plurality of heat pipes are adjacent to each other. Are side surfaces other than the side surface in contact with the hexagonal columnar container of another module-type secondary battery and the side surface in contact with the space.

According to the present invention, for example, when the temperature of the secondary battery having the module structure rises, the heat radiation amount of the cooling device (variable conductance type heat pipe) increases in accordance with the temperature rise, and as a result, The temperature rise rate of the secondary battery is decreasing. That is, the temperature rise curve after the start of discharge of the module-type secondary battery becomes a gradual curve as the temperature rises, so even if the output capacity and discharge time of the secondary battery are increased, the temperature of the secondary battery remains unchanged. The maximum battery temperature is never reached, and it becomes very easy to manage the maximum battery temperature.

Further, the temperature drop curve of the module type secondary battery after the start of charging becomes a gentle curve as the temperature drops, so that even if the output capacity or discharge time of the secondary battery is increased, The battery temperature does not fall below the discharge start temperature, and the temperature before discharge start can be managed without performing special temperature control using a heater or the like.

Further, since cooling (radiation of heat) is performed using the cooling device (variable conductance type heat pipe), the container wall of the container of the module type secondary battery is in a non-vacuum atmosphere containing a gas under normal pressure. It can be a heat insulating wall.

Further, since the heating part of the cooling device (variable conductance type heat pipe) is arranged at the bottom of the heat insulating container, the heat released from the module type secondary battery through the heat pipe is vertically emitted from the unit cell. It is only the heat that has moved downward. That is, even if the cooling device of the present invention is used, it does not cause a non-uniform temperature distribution occurring in the horizontal direction of the unit cell group, and is a cooling method effective for uniform battery cooling.

Further, even when a plurality of module type battery units described above are accommodated in a casing to form a large capacity module type secondary battery unit, the temperature management control of each module type secondary battery is performed by the above-mentioned cooling. Very easy to do with the device.

[0060]

BEST MODE FOR CARRYING OUT THE INVENTION A module type secondary battery and a module type secondary battery unit according to the present invention will be described below.
In particular, an embodiment using a NaS module battery as a module type secondary battery will be described with reference to the accompanying drawings.

FIG. 1 is a plan view schematically showing a NaS module battery 1 according to the present invention and a cooling device 2 provided in the NaS module battery 1. FIG.
It is a side view which shows the module battery 1 and the cooling device 2 schematically. Note that FIG. 2 shows, for example, N stacked in three stages.
In the aS module battery unit, the module battery located in the middle stage is shown.

The NaS module battery 1 is shown in FIGS.
As shown in FIG. 2, a prismatic heat insulating container 3 whose plane (upper surface) is represented by a rectangle, a battery storage container 4 made of metal housed in the heat insulating container 3, and a battery storage container 4 housed in the battery storage container 4 5, and a partition lid 6 for partitioning the inside of the heat insulating container 3 including the battery storage container 4.

The heat insulating container 3 is not a conventional vacuum container wall but a container wall containing a fibrous heat insulating material and filled with atmospheric pressure gas having a low thermal conductivity such as argon gas. For example, a heat collecting bottom plate 10 made of aluminum, steel, iron or the like is installed. The battery compartment is
A plurality of unit cells 5 are installed on the heat collecting bottom plate 10.
5 are housed in the battery storage container 4 in an upright state.
Further, the plurality of unit cells 5 ... 5 are fixed by filled and fixed sand (filled sand). A heater (not shown) for setting the temperature when the module battery 1 is first used is provided on a part of the container wall of the heat insulating container 3.

The partition cover 6 is formed by incorporating a fibrous heat insulating material and filling with atmospheric pressure gas such as argon gas, like the container wall of the heat insulating container 3. And this partition lid 6
Is provided at a position lower than the uppermost portion of the side wall of the heat insulating container 3 by a predetermined length and in close contact with the side wall. A gap between the partition lid 6 and the uppermost part of the side wall is filled with a heat insulating partition layer 11 formed of a heat insulating material. The partition lid 6 and the heat insulating partition layer 11 form an upper lid portion 12 of the heat insulating container 3.

Further, the NaS module battery 1 has an L-shaped variable conductance heat pipe which is the cooling device 2 of the present embodiment.
For example, two 15 are provided.

Variable Conductance Heat Pipe 15
Are arranged so that the condensing part (heat radiating part) of the pipe 15 is parallel to the side wall surface of the heat insulating container 3. The heating part of the pipe 15 is bent substantially at right angles to the condensing part and embedded in the heat collecting bottom plate 10 of the heat insulating container 3 to form an L-shape as a whole. The pipe length of the heating portion embedded in the heat collecting bottom plate 10 is a predetermined length (in the present embodiment, about half the length of the bottom plate 10).
Further, the heat radiation fins 16 are attached along the axial direction of the pipes forming the heat radiation portion (omitted in FIG. 2 and described in detail in FIG. 3 shown later).

The structure of the variable conductance type heat pipe 15 of this embodiment is shown in FIG. According to FIG. 3, the heat pipe 15 includes a gas reservoir 15A and a heat radiating portion 15B.
And a heat insulating unit 15C and a heating unit 15D. The pipe forming the gas reservoir 15A is the heat radiating portion 1
It has a longer diameter than the pipes forming 5B and the like, and is designed so that a required amount of non-condensable gas can be stored (the stored gas is referred to as a gas reservoir 20). The periphery of the pipe forming the gas reservoir 15A is covered with a heat insulating material 21.

Non-condensable gas based on the gas pool 20 is retained in the pipe forming the heat radiating portion 15B. And the radiation fin 16 is attached in the pipe along the axial direction. A portion extending from a predetermined position s along the axial direction of the radiating fin 16 to the heat insulating portion side and the heating portion side is formed in a tapered shape as shown in FIG. Further, the radiation fin 16 has a slit 23 perpendicular to the axial direction, and the radiation fin area is divided along the axial direction.

The pipe forming the heating portion 15D is embedded inside the bottom plate 10 as described above. In addition, pipes (bottom plate 10) that constitute the heating unit 15D and the heat insulating unit 15C.
A heat working medium M is enclosed in the pipe).
As the working medium M, any medium can be used as long as it is a boiling liquid. In particular, in the present embodiment, a heat carrier oil (for example, Dowtherm A (registered trademark of Dow Chemical Co.) manufactured by Dow Chemical Co.) is used. This Dowtherm A has an operating temperature range shown in FIG. 4 and a vapor pressure of 187 mmHg to 4.
It is 5 kg / cm ² , and when it is depressurized or pressurized, boiling and condensation are repeated within the above temperature range, and therefore it is suitable for use as a working medium of a heat pipe.

On the other hand, the inner wall of the heat pipe 15 is provided with a wick material 25 formed of, for example, a metal net. The wick material 25 is a condensed working medium M.
The self-pumping operation is carried out to convey the heat to the heating unit 15D side by the capillary pressure. In addition, a heat conducting rod 26 is arranged along the axial direction of the pipe that constitutes the gas reservoir 15A, the heat radiating portion 15B, and the heat insulating portion 15C of the heat pipe 15. This heat conduction rod 2
A fin 27 is attached to the tip of the gas reservoir 15 </ b> A of No. 6.

The function of the variable conductance type heat pipe 15 described above will be described with reference to FIG.

In the heat pipe 15 until the temperature of the heating portion 15D reaches T1 (a value included in the temperature operating characteristic range (300 ° C to 350 ° C) of the NaS module battery, for example, set to about 300 ° C). The non-condensable gas is previously sealed in the heat pipe 15 by adjusting the sealing pressure so that the working medium M sealed in is not boiled. Therefore, even if the heating portion 15D is heated, its temperature reaches T1. Up to the function of the heat pipe 15 (continuous boiling / condensation)
Does not occur (the region of "temperature T1A << T1 of the heating portion" is called the dead zone of the heat pipe (that is, the region outside the operating range)). Therefore, the temperature of the heating unit 15D is T1.
In the temperature range up to the temperature range of
The heat is radiated at an extremely low heat penetration flow rate corresponding to the heat quantity Q1. In other words, in this dead band,
The temperature change (increase) is higher than the change in heat transmission rate. At this stage, the assumed boundary surface between the vapor of the working medium M and the non-condensable gas (hereinafter referred to as the non-condensable gas boundary surface) is at the position "a" in Fig. 3 (the full length area of the heat dissipation portion 15B).

The heating of the heating portion 15D progresses, and the temperature is T
When the temperature is raised to 1 or more, the working medium M starts to boil, the internal pressure of the heat pipe 15 rises, and the noncondensable gas is compressed. As a result, the noncondensable gas interface begins to rise.

When the temperature of the heating unit 15D reaches TA and the vapor of the working medium rises as the noncondensable gas boundary surface rises, the heat radiating unit 15 vaporizes.
When the temperature reaches B, the condensation action starts via the radiation fins 16 and the heat-penetrating function of the heat pipe 15 occurs. However, in this state, the condensing action has not yet occurred from the entire area of the heat radiating portion 15B, so the heat transmission flow rate is still small (see QA corresponding to the temperature TA in FIG. 3).

When the noncondensable gas boundary surface further rises as the temperature of the heating section 15D further rises, the heat radiating section 15
An effective condensing action occurs over a wide range of B, and the heat transmission flow rate rapidly increases. When the temperature of the heating unit 15D reaches T2 (for example, about 330 ° C.) or more and the non-condensable gas boundary surface reaches the position "b", the heat penetration flow rate Q2 of a general heat pipe is obtained (see FIG. 3). ). At this time, T1
The temperature difference between .about.T2 is, for example, about 5 DEG C. to 30 DEG C., and the heat transmission flow rate ratio is "Q2 / Q1 >>10", for example. It should be noted that, when the temperature is lowered, an action opposite to the above-mentioned action is performed.

As described above, the variable conductance heat pipe 15 of this embodiment is actually moved by moving the boundary surface of the non-condensable gas staying in the heat radiating portion 15B according to the temperature change of the heating portion 15D. By changing the length acting as the heat radiating portion 15B, the heat transmission flow rate of the heat pipe 15 itself can be significantly changed.

When the vapor reaching the heat radiating portion 15B condenses in the gas pool 20, the temperature of the gas pool 20 decreases, and the temperature of the gas pool 20 and the temperature of the working heat medium M are reduced. There is a difference between them. When this temperature difference becomes large, the position of the boundary surface of the non-condensable gas becomes unstable, and the temperature of the heating section 15D and the heat transmission flow rate cannot be determined uniformly.

Therefore, in the heat pipe 15 of this embodiment, the circumference of the pipe forming the gas reservoir 15A is covered with the heat insulating material 21, and the gas reservoir 15A, the heat radiating portion 15B and the heat insulating portion 15C of the heat pipe 15 are covered. Since the heat conduction rod 26 is inserted into the pipe of No. 1 to thermally couple the gas reservoir 15A and the working medium M, the temperature of the gas reservoir 20 is maintained high and the above-mentioned non-condensable gas boundary surface position is maintained. This prevents variations in the temperature of the heating part D and the heat transmission flow rate due to the instability.

Further, in the heat pipe 15 of this embodiment, the boundary surface of the initial non-condensable gas (the temperature T of the heating portion 15D is
Since it is necessary to stabilize the position (corresponding to 1),
It is important to suppress the unnecessary amount of condensation of the working medium (that is, the heat transmission flow rate) near the temperature T1 to a low level, and it is also important to increase the amount of heat radiation of the heat radiation portion 15B.

Therefore, the heat pipe 1 of this embodiment
According to No. 5, while increasing the area of the radiation fin, the slits 23 are formed in the fin 22 perpendicularly to the axial direction of the pipe to divide the area of the radiation fin along the axial direction. That is, the working medium M has fins that radiate heat according to the rising position of the heat radiating portion 15B in the pipe, and therefore the working medium M rising position in the heat radiating portion 15B (that is, the boundary surface of the non-condensed gas When the ascending position) is around the “a” point, the working medium is condensed only through the fins closest to the heating unit 15D, so that the condensation amount (heat transmission flow rate) of the working medium is suppressed to be low.

Further, for the same purpose, since the radiation fin 16 is tapered toward the heating portion 15D side,
The area of the radiation fin 16 at the point "a" is the smallest as compared with the area of the entire radiation fin 16. Therefore, it is possible to suppress the unnecessary amount of condensation of the working medium M near the temperature T1 while keeping the area of the radiation fin 16 on the side of the gas reservoir 15A as large as necessary.

By the way, since the upper surface and the bottom surface of the NaS module battery 1 are in contact with the upper-side module battery and the lower-side module battery (see the one-dot chain line in FIG. 2) through the heat insulating partition layer, the heat from the upper surface and the bottom surface is not generated. Movement can be ignored.

Therefore, the heat radiation from the NaS module battery 1 is released to the outside air through the following two routes.

First route ... A route through the side wall surface of the heat insulating container 3 to the outside air (route a in FIG. 2). Second path ... A path that moves vertically downward from the unit cells 5 ... 5 and is discharged from the heat collecting bottom plate 10 to the outside air via the heat pipe 15 (path b in FIG. 2).

In the present embodiment, the variable conductance heat pipe 15 having the above-mentioned function is used to radiate most of the total heat of the NaS module battery 1 to control the temperature of the NaS module battery 1. .

Here, the NaS module battery 1 by the cooling system using the variable conductance type heat pipe 15 is used.
5 shows the transition of the battery temperature of FIG. 5, and with reference to FIG. 5, the method for managing and controlling the maximum battery temperature and the temperature before the start of discharge in the NaS module battery 1 of the present embodiment,
This will be described below.

A predetermined temperature before the start of discharge (eg, Ts = 28)
When the NaS module battery 1 set to 0 ° C. <T1 (300 ° C.) starts discharging, the temperature of the module battery 1 is set to the heat pipe 15 as shown in FIG. 3 until the temperature reaches T1. Since the heat radiation amount is low in the dead zone, the temperature rises rapidly (proportionally) (Fig. 5; time t10 ~
t11).

When the module battery temperature rises above T1, as shown in FIG. 3, the condensing action of the heat pipe 15 increases and the temperature rise rate (gradient) becomes gentler.
The ascending curve draws a parabola (Fig. 5; time t11 to t1).
2). At the end of discharge (FIG. 5; time t12), the module battery temperature reaches the maximum temperature (Tm = T2 = about 330 ° C.).

After the end of discharge, there is no heat generation from the module battery 1, and the module battery temperature drops rapidly (proportionally) due to the high heat dissipation performance (FIG. 5; time t12 to t13 and T2 → TA in FIG. 3). See the reduction rate of heat transmission flow rate),
As the module battery temperature decreases, the heat dissipation performance decreases,
The temperature drop rate (gradient) gradually becomes gentle, and the temperature drop of the module battery is T
1 is reached (FIG. 5; time t13 to t14 and T in FIG. 3).
(Refer to the rate of decrease in heat transmission rate at A → T1).

When the module battery temperature drops below T1, as shown in FIG. 3, the heat pipe 15 enters the dead zone, so that the heat radiation performance deteriorates, and the temperature drops gradually. That is, after the temperature of the module battery drops below T1, the module battery 1 starts charging (FIG. 5; time t15), and after charging is completed (FIG. 5; end time t1).
6) Even if the time changes until the start of the next discharge (FIG. 5; time t17) (t14 to t15 to t16 to t17), the module battery temperature drops very slowly. The module battery temperature does not reach the pre-discharge temperature Ts without special temperature control. The pre-discharge start temperature Ts ′ at the start of the next discharge does not necessarily match the pre-discharge start temperature Ts (Ts−Ts ′ = Δt, and this Δt does not become “0”). In both discharge tests, there is no effect because it is adjusted by the temperature T1 during heating.

As described above, according to this embodiment,
Since the amount of heat radiated by the heat pipe increases as the module battery temperature rises, the temperature rise curve near the battery maximum temperature Tm can be set very gently, and the module before the discharge start temperature Ts is reached. The temperature drop curve can also be set very gently.

Therefore, even if the output capacity of the NaS module battery is increased, as shown by the phantom line (CA) in FIG. 5, the temperature rise curve during discharging is almost unchanged, and the maximum temperature of the module battery can be controlled very easily. become. Similarly, even if the discharge time of the NaS module battery is increased (discharge end time t12 → tB), as shown by the phantom line (CB) in FIG. 5, the temperature rise curve during discharge and the module battery maximum temperature at time tB Is almost unchanged, and it becomes very easy to manage the maximum temperature of the module battery.

That is, by using the cooling system of this embodiment, it is possible to increase the operating output and discharge time of the NaS module battery, and it is possible to greatly improve the practicality of the NaS module battery.

Further, according to the present embodiment, as shown in FIG. 5, since the module battery temperature drops very slowly after the module battery temperature drops below T1, the module battery temperature drops. Reaches automatically around the temperature before discharge Ts and is maintained at that value. That is, by using the heat pipe of this embodiment, it is possible to manage the temperature before the start of discharge without performing special temperature control using a heater or the like. As mentioned above,
Variations (Δt) occur in the pre-discharge temperatures Ts and Ts ′, but the higher the module battery temperature, the more the amount of heat radiation, so the variations have no effect on the maximum module battery temperature.

Further, in the present embodiment, the temperature control of the module battery is performed by the heat radiation method using the heat radiation fins using natural convection and having no movable portion, so that the reliability is very high.

Furthermore, according to this embodiment, NaS
The heat insulation container of the module battery is composed of a container wall filled with atmospheric pressure gas with low thermal conductivity such as argon gas, and further, with a partition lid structure without a mating part between the lid and the heat insulation container. The amount of heat radiated through the wall is
Since there is no heat radiation from the top and bottom surfaces of the module battery and the mating portion, the heat radiation area ratio is reduced to about 1/2 or less as compared with the module battery using the conventional heat insulating container. Therefore, it is not necessary to use a vacuum heat insulating container having a high heat insulating property as the heat insulating container. As a result, the cost of the NaS module battery can be reduced. In addition, the cost required to maintain and secure the degree of vacuum of the vacuum insulation wall, which was necessary in the past,
Human resources and equipment can be eliminated. Even if the shape of the upper lid of the heat insulating container is greatly simplified, heat loss does not increase sharply and thermal efficiency can be secured.

Further, according to the cooling method using the heat pipe of this embodiment, the amount of heat released through the heat collecting bottom plate and the heat pipe is only the amount of heat moved vertically downward from each unit cell. That is, the heat dissipation method of the present embodiment does not cause the temperature distribution generated in the horizontal direction of the unit cell group, and can provide a cooling method effective for uniform battery cooling.

On the other hand, Na provided with the cooling device of the present embodiment
NaS stacked in 3 layers as an S module battery
Although the module battery located in the middle stage of the module battery unit has been described as an example, a NaS module battery unit in which the NaS module batteries including such a cooling device of the present embodiment are arranged in a three-dimensional matrix may be configured. it can.

FIG. 6 shows three NaS module batteries 32 having the cooling device (variable conductance type heat pipe 31) according to the present embodiment in a casing 30, three in the x direction (horizontal direction), and the y direction (vertical direction). ), Five in the z direction (height direction), three-dimensional matrix (3 × 2 ×
5) is a front view schematically showing an example of the NaS module battery unit 33 arranged in FIG. 5), and FIG. 7 is a side view of the NaS module battery unit 33. It should be noted that the radiation fin 34 of the heat pipe 31 is shown only for one NaS battery module, and the rest is omitted.

According to FIG. 6, each NaS battery module 3
The heat pipe 3 is provided outside the second heat pipe 31.
A heat insulating plate 35 that guides the heat radiation from 1 in a predetermined direction is provided. A heat insulating material 36 is embedded between the NaS module batteries 32 and between the casing 30 and the NaS module batteries 32, so that heat radiation from other than the heat pipe 31 of each NaS module battery 32 is suppressed as much as possible. Due to the structure, the energy efficiency of the battery can be improved.

Further, as described above, all the NaS module batteries 32 are cooled (heat radiation) through the heat pipes 31, so that each NaS module battery 32 is cooled.
Can be arranged as close as possible, that is, in a close-packed manner as far as the handling is permitted for inspection, repair and the like. this is,
This is because it is no longer necessary to provide a gap between the adjacent NaS module batteries, which has been conventionally required to secure a passage for the cooling air of each NaS module battery 32. Therefore, the NaS module battery unit 33 as a whole can be made compact while accommodating a large number of NaS battery modules 32.

Further, in this embodiment, the NaS module battery is constructed by using (the container wall (side container part) of) the heat insulating container 3 and the upper cover part 12 (the partition cover 6, the heat insulating material 11) (see FIG. 8 ( a) and (b)), the present invention is not limited to this. For example, as shown in FIGS. 9 (a) and 9 (b), the side wall surface on which the heat pipe 15 is provided (heat insulating container) Only the side wall surface 3A and the side wall surface (insulating container wall) 3B facing the side wall surface 3A may be left, and the other insulating container walls may be deleted (note that the part where the insulating container wall is deleted is the battery). Only the wall surface of the containment vessel 4 exists).

This module battery structure is particularly effective in the case of the unit structure shown in FIGS. 6 to 7 in which a heat insulating material is interposed between the module batteries. That is, in the unit structure, since a heat insulating material can secure a heat insulating state between the adjacent module batteries, a side wall surface (container wall) other than the side wall surface on which the heat pipe 15 is provided and the side wall surface facing the side wall surface is Since it is unnecessary except for operability such as movement, as shown in FIG. 9, this container wall can be deleted, and the compactness of the NaS module battery can be improved.
In addition, cost can be reduced.

Further, according to FIGS. 10A and 10B, the container wall is only the side wall surface (insulating container wall) 3A provided with the heat pipe 15, and the other insulating container walls are made of protective steel. By making the wall 40, the compactness is maintained while increasing the number of the unit cells 5 ...
Cost can be reduced.

By the way, in the present embodiment, the heat pipe 15 is provided on one side surface side of the heat insulating container 3, but the present invention is not limited to this, and a plurality of (in each side wall surface of the heat insulating container 3 For example, they may be provided on the side walls facing each other. That is, as shown in FIGS. 11A and 11B, in the pair of heat pipes 15a and 15b, the condensing portions of the pipes 15a and 15b are parallel to the opposite side wall surfaces 3a and 3b of the heat insulating container 3, respectively. Are arranged as follows. The heating parts of the pipes 15a and 15b are bent substantially at right angles to the condensing part and embedded in the heat collecting bottom plate 10 of the heat insulating container 3 to form an L shape as a whole. The pipe length of the heating portion of the heat pipes 15a and 15b embedded in the heat collecting bottom plate 10 is, for example, the bottom plate 1
When the length is about 1/3 of 0, the heat dissipation efficiency is good.

Thus, the side wall surfaces 3 of the heat insulating container 3 which face each other
heat pipes 15a and 15b on a and 3b, respectively
The heat radiation efficiency can be improved as compared with the heat pipe according to the above-described embodiment because the heat pipe is provided.

Further, as shown in FIG. 12, the heat insulating container 3
On all the side wall surfaces 3a to 3d side of the heat pipes 15a to 1
5d may be provided respectively, and the heat dissipation efficiency can be further improved.

In the present embodiment, the NaS module battery is constructed by using a heat insulating container having a prismatic shape whose plane is represented by a rectangle. However, in the present invention, the NaS module battery is constructed by a cooling device using a heat pipe. Because of the cooling configuration, the shape of (the heat insulating container of) the module battery is almost not limited. That is, the NaS module battery may have a polygonal columnar shape such as a hexagonal column whose upper surface or bottom surface is represented by a hexagon, or a cylindrical shape whose upper surface or bottom surface is represented by a circle.

FIG. 13 is a battery module unit in which a plurality of NaS module batteries 46 are arranged in a three-dimensional matrix (4 × 2 × 4) using a hexagonal columnar heat-insulating container 45 whose top and bottom are represented by hexagons. It is a schematic plan view showing 47, FIG. 14 is a schematic front view of the battery module unit 47, and FIG. 15 is a schematic side view of the battery module unit 47.

As shown in FIGS. 13 to 15, each module 46 (insulation container 45 thereof) has two adjacent side surfaces 4 facing the casing 48 (not in contact with other modules).
Heat pipes 50 are provided at 5a and 45b, respectively. Further, the heat radiation fins 51 of each pipe 50 are installed parallel to the side surfaces 45 a and 45 b of the heat insulating container 45.

In addition, the battery module 46 (the heat insulating container 4
Since the shape of 5) is a hexagonal prism whose plane and bottom surface are represented by hexagons, as shown in FIGS. 13 to 15, each battery module 46 is placed in a casing 48 via a heat insulating material 47 without any gap. It can be arranged (so-called close-packed).

Therefore, as compared with the conventional battery module unit, the arrangement efficiency of the modules is improved and the power storage efficiency of the entire unit is improved.

Further, since the radiation fins 51 provided on the heat pipe 50 can be installed in parallel with the side surfaces 45a and 45b of the heat insulating container 45, the radiation fins 51 can be installed.
Of the heat radiation fins 51 can be suppressed, and the installation space of the radiation fins 51 can be reduced.

Further, when the shape of the battery module 46 is a hexagonal column whose plane is represented by a hexagon, as shown in FIG. 16, a pair of the modules 46A are formed in pairs, and each module 46A has a space in the center. It is also possible to arrange them adjacently. With this arrangement, the heat pipe 50
The side surfaces of each module 46A on which A can be installed are three side surfaces on the side of the casing 48 and the side surface on the side of the central gap, which is convenient.
Compared with the module arrangement structure of FIG. 13 above,
The number of installable side surfaces of the heat pipe 50A is increased, and the heat dissipation efficiency can be further improved.

On the other hand, in the above-described embodiment and its modification, the example using the NaS battery as the secondary battery is shown.
The present invention is not limited to this. For example, FIG.
As shown in FIG. 21, a secondary battery other than the NaS battery may be used.

FIG. 17 is a diagram showing a schematic structure of a zinc / chlorine battery, and the operating principle of the zinc / chlorine battery will be described with reference to FIG.

According to FIG. 17A (during charging), zinc chloride in the electrode group 55 is divided into zinc ions, chlorine gas, and electrons. The chlorine gas in the divided gas is sent to the hydrate tank 57 via the gas liquid pump 56 and accumulated as chlorine hydrate. On the other hand, the zinc ions in the separated water are stored in the electrolytic solution tank 58.
Through the liquid pump 59 to the electrode group 55, and the electrons supplied from the external power source are received to return to zinc.

Further, according to FIG. 17B (during discharge),
Zinc in the electrode group 55 releases electrons to the external circuit to become zinc ions, and the zinc ions move to the positive electrode side through the electrolytic solution tank 58. On the other hand, the chlorine gas generated from the hydrate tank 57 moves to the positive electrode side via the liquid pump 59. The zinc ions moved to the positive electrode side react with electrons and chlorine gas supplied from the external circuit to become zinc chloride.

FIG. 18 is a diagram showing a schematic structure of a zinc / bromine battery, and the operating principle of the zinc / bromine battery will be described with reference to FIG.

According to FIG. 18 (during charging), zinc bromine (ZnBr 2) in the positive electrode 60 is divided into zinc ions (Zn ²⁺ ), bromine (Br 2), and electrons (2e ⁻ ). Bromine (Br2) in the divided portion is sent to and accumulated in the positive electrode liquid storage tank 61. On the other hand, the zinc ions (Zn ²⁺ ) in the split flow to the negative electrode 64 side through the electrolytic solution tank sent from the negative electrode solution storage tank 62 via the pump 63, and the electrons supplied from the external power source ( 2e ^-) Back to the zinc (Zn) received a.

Further, according to FIG. 18 (during discharge), the negative electrode 6
2 zinc (Zn) emits electrons (2e ⁻ ) to the external circuit to become zinc ions (Zn ²⁺ ), and the zinc ions (Zn 2
²⁺ ) moves to the positive electrode 60 side through the electrolytic solution tank. on the other hand,
Bromine (Br2) generated from the positive electrode liquid storage tank 61 moves to the positive electrode 60 side via the pump 65. The zinc ions (Zn ²⁺ ) that have moved to the positive electrode 60 side react with electrons (2e ⁻ ) and bromine (Br 2) supplied from the external circuit to become zinc bromide.

Further, FIG. 19 is a diagram showing a schematic structure of a redox flow type battery, and the operating principle of the redox flow type battery will be described with reference to FIG.

C stored in the Cr ²⁺ / Cr ³⁺ tank 70
A solution of chloride of r ²⁺ ion in hydrochloric acid (negative electrode solution) is supplied to the pump 7.
1 is sent to the central circulation type electric field tank 72 and penetrates into the negative electrode 73 made of carbon cloth, and the external circuit 74 (inverter 7
5. Electrons are discharged (discharged) to the substation equipment 76) and Cr ³⁺
Is oxidized. On the other hand, the hydrochloric acid solution of the chloride of Fe ³⁺ ions (positive electrode solution) stored in the Fe ³⁺ / Fe ²⁺ tank 77 is sent to the positive electrode 79 (carbon cloth) of the flow type electric field tank 72 by the pump 78. External circuit 74 (inverter 75, substation 7
The electrons are received (charged) from 6), and Fe ³⁺ is reduced to Fe ²⁺ .

FIG. 20 shows a redox flow type battery system manufactured by using the principle of the redox flow type battery. According to FIG. 20, the negative electrode liquid stored in the negative electrode liquid tank 80 is sent to the negative electrode of the 1 kW stack 82 by the pump 81, and electrons are discharged (discharged) to the external circuit (power supply, load). Further, the positive electrode liquid stored in the positive electrode liquid tank 83 is sent to the positive electrode of the 1 kW stack 82 by the pump 84 and receives (charges) electrons from an external circuit (power source, load).
The pump 85, the voltammetry battery 86, the chromemetry battery 87, and the circuit voltage measurement battery 88 are components that monitor the charge / discharge states of the negative electrode liquid tank 80 and the positive electrode liquid tank 83.

Further, FIG. 21 is a diagram showing a schematic structure of a lead storage battery, and the operation principle of the lead storage battery will be described with reference to FIG.

This lead-acid battery has a positive electrode plate 9 separated by a separator 92 in a battery case 91 to which an exhaust plug 90 is attached.
3 (lead dioxide (PbO ₂ ) as the positive electrode active material, negative electrode plate 94
(Lead (Pb) is included in the negative electrode active material). In addition, an electrolytic solution 95 (dilute sulfuric acid H ₂ SO ₄ ) is stored in the battery case 91. A positive electrode terminal 96 is provided on the positive electrode plate 93, and a negative electrode plate 94 is provided.
A negative electrode terminal 97 is attached to.

The basic reaction formula of this lead acid battery is shown below.

[0128]

[Equation 1]

In other words, both the positive electrode active material (PbO ₂ ) and the negative electrode active material (Pb) become PbSO ₄ by discharging, and they return to the almost lost state by charging. Therefore, heavy discharge can be repeated many times.

Also in the above secondary battery (refer to FIG. 23 for characteristics and the like), the cooling device by the heat pipe of this embodiment is applied by controlling the filling pressure of the non-condensing gas based on the operating temperature and the like. be able to.

By the way, in the present embodiment, the heat radiation fins provided in the heat radiation portion of the heat pipe are formed in a tapered shape from the predetermined position s along the axial direction to the heat insulating portion side and the heating portion side. The present invention is not limited to this. That is, as in the above-described embodiment, the temperature T
In order to increase the overall amount of heat dissipation while suppressing the unnecessary amount of condensation of the working medium M in the vicinity of 1, as shown in FIG. 22, for example, as shown in FIG. You may form in a taper shape from the part 15A side.

By the way, in each of the above-described embodiments, an example in which a heat pipe is used as a cooling device has been shown, but the present invention is not limited to this. That is, the present invention is characterized by adopting a cooling system in which the amount of heat radiation changes according to the battery temperature, instead of using a simple cooling system with a constant amount of heat radiation. Therefore, any cooling device such as bimetal may be used as long as the amount of heat radiation changes according to the change in the temperature of the cooling target.

[0133]

As described above, according to the module type secondary battery and the module type secondary battery unit of the present invention, the heat radiation amount (cooling amount) is changed according to the temperature change of the module type secondary battery. Since the cooling device is used, even if the output capacity and discharge time of the secondary battery are increased, the secondary battery temperature may reach the maximum battery temperature and the secondary battery temperature may drop below the discharge start temperature. Lost. Therefore, it is very easy to manage the maximum temperature of the secondary battery and the temperature before the start of discharge without using a temperature management component such as a vacuum container or a heater that is difficult to maintain and manage and uses extra electric energy. Become. As a result, the output of the module type secondary battery and the discharge time can be changed while maintaining high energy efficiency, so that the practicality of the module type secondary battery can be greatly improved.

Further, since heat is dissipated by using the above-described cooling device (for example, variable conductance type heat pipe), the container wall surface of the module type secondary battery container is a non-vacuum heat insulation containing a gas under normal pressure. It can be a wall. That is, since the temperature control of the module-type secondary battery can be performed very easily without using the conventionally required vacuum container, the cost of the vacuum container itself and the cost required for maintaining and managing the vacuum container, etc. And it is possible to provide a very inexpensive module-type secondary battery.

Furthermore, since the heating part of the cooling device (for example, the variable conductance type heat pipe) described above is arranged at the bottom of the heat insulating container, the heat released from the module type secondary battery through the heat pipe is a unit cell. It is only the heat that moves vertically downward from the cell, and does not cause the temperature distribution that occurs in the horizontal direction of the cell group. Therefore, it is possible to correct the temperature non-uniform distribution in the horizontal direction, which has occurred conventionally, and obtain a uniform temperature distribution in each battery.

Furthermore, since it is possible to form a modular secondary battery unit by housing a plurality of modular secondary batteries equipped with the cooling device described above in a casing, a module having excellent practicability and cost performance. A type secondary battery unit can be provided.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a NaS module battery and a cooling device thereof according to an embodiment of the present invention.

FIG. 2 is a side view schematically showing the NaS module battery and its cooling device of FIG.

FIG. 3 is a diagram schematically showing the structure and function of a variable conductance heat pipe of a cooling device.

FIG. 4 is a diagram showing temperature characteristics of a working fluid (medium) used for a variable conductance type heat pipe or the like.

FIG. 5 is a graph showing changes in battery temperature of NaS module batteries.

FIG. 6 is a front view schematically showing an example of a module battery unit.

FIG. 7 is a side view schematically showing an example of a module battery unit.

FIG. 8A is a front view schematically showing a NaS module battery provided with a variable conductance heat pipe according to the present embodiment, and FIG. 8B is a schematic NaS module battery provided with a variable conductance heat pipe. FIG.

FIG. 9A is a front view schematically showing a modified example of a NaS module battery including a variable conductance heat pipe, and FIG. 9B is a modified example of a NaS module battery including a variable conductance heat pipe. The side view which shows roughly.

10A is a front view schematically showing a modified example of a NaS module battery having a variable conductance heat pipe, and FIG. 10B is a modified example of a NaS module battery having a variable conductance heat pipe. The side view which shows roughly.

FIG. 11 (a) N according to a modification of the embodiment of the present invention.
A plan view schematically showing an aS module battery and a cooling device thereof, (b) NaS according to a modification of the embodiment of the present invention.
The side view which shows the module battery and its cooling device roughly.

FIG. 12 is a plan view schematically showing a NaS module battery and a cooling device thereof according to a modification of the embodiment of the present invention.

FIG. 13 is a schematic plan view showing a modified example of the NaS battery module unit.

14 is a schematic front view showing a modified example of the NaS battery module unit of FIG.

FIG. 15 is a schematic side view showing the NaS battery module unit of FIGS. 13 and 14;

FIG. 16 is a schematic plan view showing another modification of the NaS battery module unit.

FIG. 17 is a diagram showing a schematic configuration and an operating principle of a zinc-chlorine battery.

FIG. 18 is a diagram showing a schematic configuration and an operating principle of a zinc-bromine battery.

FIG. 19 is a diagram showing a schematic configuration and an operating principle of a redox flow battery.

FIG. 20 is a diagram schematically showing an example of a redox flow type battery system.

FIG. 21 is a diagram showing a schematic configuration of a lead storage battery.

FIG. 22 is a view showing a modified example of the heat radiation fins of the heat pipe.

FIG. 23 is a diagram showing the performance and characteristics of various secondary batteries.

FIG. 24 is a diagram showing the performance and characteristics of a molten salt secondary battery using lithium as a negative electrode active material.

FIG. 25 is a graph showing the relationship between the battery temperature and the number of lives (the number of times of charging and discharging) of a lead-acid battery that operates at room temperature.

FIG. 26 is a graph showing the relationship between the battery temperature of a lead storage battery and the service life (use life).

27A is a diagram schematically showing the structure of a NaS battery alone, and FIG. 27B is an enlarged view of a portion A in FIG. 27A.

FIG. 28 is a perspective view schematically showing a conventional NaS battery having a module structure.

FIG. 29 is a graph showing changes in battery temperature of a conventional NaS module battery.

FIG. 30 (a) is a front view schematically showing a conventional NaS module battery unit, and FIG. 30 (b) is a side view schematically showing the NaS module battery unit.

FIG. 31 is a diagram showing the flow of heat flow in a NaS module battery.

[Explanation of symbols]

1,32,46,46A NaS module battery 2 Cooling device 3,45 Thermal insulation container 4 Battery storage container 5 ... 5 Single cell 6 Partition lid 10 Heat collecting bottom plate 11,36 Thermal insulation material 12 Upper lid part 15, 15a to 15d, 31, 50,50A Variable conductance type heat pipe 15A Gas storage part 15B Heat dissipation part 15C Heat insulation part 15D Heating part 16,16a-16d, 34,51,51A, 98 Heat dissipation fin 30,48,48A Casing 33,47 NaS module Battery unit

Claims (22)

[Claims] 1. A module-type secondary battery in which a plurality of secondary batteries are housed in a container to form a module, which has a heat radiation amount according to a temperature change of the module-type secondary battery, A module type secondary battery comprising a cooling device for radiating and cooling the entire type secondary battery. 2. The module type secondary battery according to claim 1, wherein the secondary battery is a sodium-sulfur battery. 3. The module type secondary battery according to claim 1, wherein the cooling device has a variable conductance type heat pipe in which a heat working medium and a non-condensing gas are enclosed. 4. The heating pipe, wherein the heat pipe encloses the heat working medium and is heated from the outside, and a condensing unit that performs a condensing action based on steam generated by heating the heat working medium by the heating unit. The module type according to claim 3, further comprising: a gas reservoir for communicating the non-condensable gas, which is communicated with the condensing unit, and the non-condensing gas enclosed in the gas reservoir is retained at a predetermined position in the condensing unit. Secondary battery. 5. The heat pipe has a heating portion disposed at a bottom portion of the container, and a pipe portion including the condensing portion is bent so as to be substantially orthogonal to the heating portion so that a side surface of the container is provided. 5. An L-shaped structure arranged substantially in parallel.
The described module-type secondary battery. 6. The cooling device has a plurality of the heat pipes, wherein each heat pipe has a heating part disposed at the bottom of the container, and a pipe part including a condensing part is provided with respect to the heating part. 6. The module-type secondary battery according to claim 5, wherein the module-type secondary battery is bent so as to be substantially orthogonal to each other and is arranged substantially parallel to at least one side surface of the container. 7. The module-type secondary battery according to claim 5, wherein a radiating fin is provided over the entire area of the condensing portion along the axial direction. 8. The module type secondary battery according to claim 7, wherein the radiating fin is formed in a taper shape from a predetermined portion along the axial direction of the condensing portion toward an end portion on the heating portion side. 9. The module mold according to claim 8, wherein in order to divide the area of said radiating fin along said axial direction, a slit is provided perpendicularly to said radiating fin along said axial direction of said condenser. Secondary battery. 10. A non-vacuum adiabatic wall surface containing a gas under normal pressure as at least one wall surface of said container.
9. The module-type secondary battery according to any one of 9. 11. The module-type secondary battery according to claim 10, wherein the at least one wall surface is a side surface adjacent to the condensing part. 12. The module type secondary battery according to claim 11, wherein the upper surface of the container is omitted and the upper surface portion is constituted by a heat insulating material and a partition lid. 13. A boundary surface between the non-condensable gas and the vapor of the heat working medium is set at a predetermined position by adjusting a sealing pressure of the non-condensable gas sealed in the gas reservoir and retained in the condenser. 13. The module type secondary battery according to claim 12, wherein the operation start temperature of the heat pipe is set to a predetermined temperature within the operating temperature range of the module type secondary battery. 14. The amount of heat radiation is an amount based on the dead zone of the heat pipe when the temperature of the heating section is lower than the operation start temperature, and when the temperature of the heating section rises above the operation start temperature. 14. The module-type secondary battery according to claim 13, wherein the temperature is set to increase in accordance with an increase in the boundary surface in the condensing part due to the temperature increase. 15. When the temperature of the heating unit drops from the maximum temperature and the temperature is equal to or higher than the operation start temperature, the amount of heat radiation is reduced by the temperature drop in the condensing unit on the boundary surface. 15. It is set so as to decrease in accordance with the temperature, and when the temperature of the heating portion drops below the operation start temperature, the amount is set based on the dead zone of the heat pipe. Module type secondary battery. 16. The temperature of the module-type secondary battery is
Until the temperature of the secondary battery reaches the operation start temperature from the temperature before the start of the test, the heat radiation amount increases linearly because it is an amount based on the dead zone of the heat pipe, and the temperature of the secondary battery. In the range where the temperature exceeds the operation start temperature,
16. The module-type secondary battery according to claim 15, wherein the heat radiation amount is set to rise in a gentle parabola because the heat radiation amount increases in accordance with the rise in the condensing portion of the boundary surface. 17. The temperature of the module-type secondary battery is
Until the temperature of the secondary battery reaches the operation starting temperature from the maximum temperature, the heat radiation amount decreases rapidly in accordance with the decrease in the condensing portion of the boundary surface, and thus the secondary battery rapidly decreases. 17. The module type secondary as set forth in claim 16, wherein, in a range in which the temperature exceeds the operation start temperature, the amount of heat radiation is an amount based on the dead zone of the heat pipe, so that the temperature drops in a gentle parabola. battery. 18. A module-type secondary battery unit, wherein a unit is constituted by housing a plurality of the module-type secondary batteries according to claim 1 in a casing. 19. The module-type secondary battery is housed in the casing in a closest packing manner, and a heat insulating material is embedded between adjacent module-type secondary batteries and between the casing and each module-type secondary battery. The module type secondary battery unit according to claim 18. 20. A plurality of module type secondary batteries according to claim 5 or 6 are housed in a casing to form a unit, and the container of the module type secondary battery in the casing has six upper and bottom surfaces. It is formed by a hexagonal columnar container represented by a polygonal shape, and the plurality of heat pipes are arranged such that a heat radiation portion thereof is substantially parallel to a side surface of the hexagonal columnar container. unit. 21. The side surfaces of the hexagonal columnar containers of the module-type secondary battery adjacent to the heat dissipation part of the heat pipe are side faces other than the side surfaces adjacent to each other between the hexagonal columnar-shaped containers of the adjacent module type secondary batteries, 21. The module type secondary battery unit according to claim 20, wherein the module type secondary batteries formed of a hexagonal columnar container are arranged in a closest packed manner. 22. A unit is constructed by housing a plurality of the module type secondary batteries according to claim 6 in a casing,
A plurality of module-type secondary batteries formed of the hexagonal columnar container are arranged adjacent to each other so that a space is formed in the center of each secondary battery, and the heat dissipation parts of the plurality of heat pipes are adjacent to each other. A side wall of the hexagonal columnar container of the module type secondary battery is a side face other than the side face of the other module type secondary battery in contact with the hexagonal columnar container, and a side face of the space contacting the space.