JPS63175355A - Sodium-surfur cell - Google Patents

Abstract

PURPOSE:To make a cell temperature uniform, by setting up a heat pipe in a heat insulating furnace, and connecting this heat pipe thermally to the radiator installed at the outside of the heat insulating furnace. CONSTITUTION:A furnace wall of each surface of a heat insulating furnace 2 housing a sodium-surface cell 1 is formed with an adiabator 3 in ununiformed specifications so as to cause dominant heat flux inside the furnace to be unevenly distributed in one direction, a lot of heat pipes 4 and 8 are set up on the direction where the heat flux is unevenly distributed, and these heat pipes 4 and 8 are thermally connected to the radiator 5 installed at the outside of the heat insulating furnace 2 is constituted of the adiabator 3 all over the surfaces. In this case, the value of heat conductivity/thickness of the dadiabator is set to the large in the longitudinal surface and smaller in the vertical surface.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention measures changes over time in the temperature of each battery in each mode of charging, discharging, and resting, and the temperature distribution of a large number of batteries at each time point. The present invention relates to a sodium-sulfur battery with heat pipes that can be maintained in a temperature range.

[Conventional technology]

In sodium-sulfur batteries used for power storage, the amount of heat generated changes depending on charging, discharging, and resting modes. However, for normal operation, through all modes,
It is necessary to maintain changes over time and temperature distribution within predetermined ranges.

Conventionally, in order to maintain the temperature of sodium-sulfur batteries and to keep a large number of cells at a uniform temperature, air was circulated inside a heat insulating furnace with insulation walls that housed the cells, and when the amount of heat generated was large, a small amount of air was It was cooling by drawing in outside air.

In addition, as shown in Japanese Patent Application Laid-open No. 59-143281, in order to maintain the battery temperature within a certain range, the catalytic converter
A structure has been proposed in which a cooling section 6 and cooling air is introduced and cooled by cooling fins 24, and these and a battery are connected via a heat pipe.

[Problem that the invention seeks to solve]

However, the conventional air circulation system described above has the following problems.

(1) Since the amount of convective heat transfer to the airflow is not very large, the temperature becomes non-uniform due to the influence of other competing forms of heat transfer (such as radiation). In order to make the temperature uniform, a large amount of air must be circulated, which requires a large amount of power.

(2) It is difficult to make the air flow non-uniform at each location in the heat-retaining furnace, and temperature deviations are likely to occur.

(3) Ancillary equipment such as fans and ducts increase the space occupied by the equipment.

(4) Due to the accompanying equipment, it is difficult to insulate the furnace wall, which tends to increase heat loss.

(5) Since rotating equipment is required, equipment costs and maintenance/inspection costs are relatively high.

(6) Scaling up is difficult because it is difficult to theoretically predict airflow.

(7) In order to save power, it is desirable to stop the fan when the fan is at rest, but it is difficult to predict the temperature distribution when the fan is stopped.

In addition, in the structure described in JP-A-59-143281, in a small battery, the heat balance is usually a bit excessive in heat radiation, so it is appropriate to maintain the temperature with a heat source called a catalytic converter. Large batteries, such as 50 to 60, may have insufficient heat dissipation, so it is best to keep the temperature within a certain range by using the heat generated and retained heat by the battery itself in order to survive in terms of energy. In addition, in large batteries, in order to maintain the temperature distribution within the furnace within a certain range, some kind of mechanism is required to equalize the temperature inside the furnace.

The present invention was made in view of the above points, and is a large-sized sodium hydride that maintains a constant temperature range by guiding the heat inside the insulating furnace to a heat radiating section provided outside the insulating furnace through a heat pipe. - The purpose is to provide sulfur batteries.

[Means for solving problems]

The sodium-sulfur battery of the present invention will be described with reference to the drawings. A heat-retaining furnace 2 containing a sodium-sulfur cell 1 is provided with a heat vibrator 4 for maintaining the temperature within a certain range.
8 is disposed, and the heat vibrator is thermally connected to a heat radiating section 5 provided outside the heat insulating furnace.

[For production]

The heat generated by the cell 1 is guided to the heat radiating section 5 via the heat vibrator 4.8 and radiated, and the temperature inside the heat retaining furnace 2 is maintained within a certain range. At this time, even if the battery generates heat unevenly, the heat pipe 4 keeps the battery temperature uniform.

In addition, in a heat-retaining furnace that is simply provided with a heat insulating material, the temperature of only the batteries on the outer periphery tends to drop, but in the present invention, heat is carried away from the internal batteries by the heat vibrator 4, and the battery temperature is uniform. is maintained.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, unless there is a specific description, the materials, shapes, relative positions, etc. of the components described in this example are not intended to limit the scope of the present invention to these, but are merely illustrative. Just an example.

Example 1 As shown in FIGS. 1 and 2, in the sodium-sulfur battery of this example, the furnace walls on each side of the heat-retaining furnace 2 that houses the sodium-sulfur cell 1 are used as the dominant area in the furnace. In order that the heat flux is unevenly distributed in one direction, it is formed of heat insulating materials 3 with non-uniform heat insulation specifications, and a large number of heat pipes 4.
8 is arranged, and the heat pipe 4.8 is thermally connected to a heat dissipation section 5 provided outside the heat retention furnace 2.

The heat insulating furnace 2 has front and back (left and right directions in Figure 1), top and bottom,
Each of the left and right sides is composed of a heat insulating material 3. In this case, the value of thermal conductivity/thickness (k/d) of the heat insulating material is set to be large on the front and rear surfaces and small on the top and bottom surfaces. For example, let the front and rear /d be approximately (top and bottom /d) x 4.3. Since there are other adjacent furnaces 6 in the left-right direction (vertical direction in FIG. 1), the heat flux is negligibly small.

Figure 4 shows the example in this example! The 0 condition, which is a schematic diagram of the change in battery temperature during the cycle, is the calorific value of the battery Qi = 6.
900kcal/H1 Heat radiation amount from the furnace surface Qs-140
0kcal/H, exhaust heat amount Qe = 2800kcal/
It is H.

Depending on the mode of operation as shown in FIG. 4, excess heat generated within the furnace may be discharged, so in this example, radiant heat receiving plates 7 are provided on the front and rear surfaces of the inside of the furnace.

This radiant heat receiving plate 7 is connected to a heat radiating part 5 such as a heat exhaust fin outside the furnace through a plurality of heat pipes 8. Each heat vibe 8 is connected to a different heat exhaust fin, and each connection line has a valve 10 in the middle. (This valve is ON, O
The amount of heat exhaust is adjusted by changing the total area of the effective heat exhaust fins in stages using FF).

Further, an internal heat equalizing plate 11 and a heat pipe 4 are arranged in the front-rear direction so as to be in contact with the side surface of the sodium-sulfur cell 1. The internal heat equalizing plate 11 is for increasing the area for receiving radiation from the cell 1, and is welded to the heat pipe 4.

Further, each heat pipe 4 is welded to an external heat equalizing plate 13 at the front end (or rear end) of the sub-module case 12. A heat insulating material 14 is arranged between the external heat soaking plate 13 and the cell 1 at the end. Note that 15 is wiring.

Next, the operation of the sodium-sulfur battery configured as described above will be explained.

In the mode that dissipates excess heat, the radiation heat receiving plate 7 is located on the front and rear surfaces, so the heat flow mainly goes in the horizontal and front-back directions.In other modes, the heat flow is also large because the /d is large on the front and rear surfaces. The heat flow mainly occurs from the front and rear surfaces, and as expected, the heat flow is directed horizontally and in the front-rear direction.As the heat pipes are arranged in this direction,
The temperature difference in this direction is small (according to a trial calculation, the temperature difference between both ends of the heat pipe is within 1°C).

Since the heat transfer between each cell 1 and the internal heat equalizing plate 110 is carried out by radiation, the temperature difference between the two is slightly large (according to the trial calculation, it is about 6 degrees Celsius for the maximum heat flux). The temperature difference between single cells is small because it occurs evenly in the battery.
Since the cells at the ends are close to the external heat soaking plate 7, the temperature will drop a little more than the others, but it is expected that the temperature will drop by 2 to 3 degrees Celsius.

In the vertical direction, heat must be transferred by the heat conduction of the cells themselves and the heat conduction of the internal and external heat equalizing plates, but since the amount of heat radiated from the top and bottom surfaces of the furnace is small, in order to maintain the temperature of the inner surface of the furnace. Only a small amount of heat is required, and the temperature difference caused by this heat flow is small (according to a trial calculation, the temperature difference between the top and bottom ends of a single cell is about 3°C).

The sodium-sulfur battery in this example has the following features and advantages in addition to the above.

(1) Since the heat pipe is attached to the side of the cell, the heat transfer area increases compared to placing it on the top or bottom of the battery.

(2) An internal heat equalizing plate is provided to increase the heat transfer area between the heat pipe and the cell.

(3) In order to improve radiation conduction between the heat pipe and the cell, it is preferable to increase the emissivity with paint.

(4) A heat insulating material is provided between the front and rear cells and the external heat equalizing plate so that the cells at the front and rear ends do not become colder than the other cells.

(5) Since the heat pipes are grouped in each sub-module case, handling of the sub-module cases is easy.

(6) Heat is transferred between the furnace body and the sub-module case by radiation, and there is no mechanical connection between the furnace ceiling (
It is easy to open and close the lid (lid) and handle the submodiere case.

Embodiment 2 In this embodiment, as shown in FIG. 3, a box 17 containing a heat storage material 'Jj16 such as lead is attached to an external heat soaking plate 13. The /d value of the heat insulating material of the furnace wall was about 1.
It should be about 5 times as thick (60% thicker with the same material).

The heat exhaust mechanism is the same as in Example 1 and 11, but the heat load (
The heat transfer amount of the heat pipe and the total area of the heat exhaust fins are approximately 10% of those in the first embodiment. Also, only one heat pipe is used. The amount of exhaust heat is adjusted only by turning it on and off, and there is no multi-step switching.

The temperature change of the battery during one cycle according to this example is shown in FIG.
1/H, heat radiation amount from the furnace surface Qs-2300kcal/
H.

Exhaust heat amount Qe = Okcal/Hs Capacity of heat storage material 1500
It is 0 kcal. In addition, for ease of comparison, the conventional method is shown in Figure 6.The conditions for this conventional method are the heat generation amount of the battery (li = 6900 kcal/L, the heat radiation amount from the furnace surface Qs -1400 kcal/f[, the exhaust heat amount Qa=280
It is 0kcal/H1.

As can be seen from FIGS. 5 and 6, despite the large amount of heat radiated from the furnace surface due to the action of the heat storage material, the temperature change width during one cycle is the same as that of the conventional method and Example 1. It is maintained. In addition, since the amount of exhaust heat is -0, the heat exhaust mechanism may be one with a small capacity for control.Other configurations and functions are as shown in Example 1.
It is similar to

〔Effect of the invention〕

Since the present invention is configured as described above, it has the following effects.

(1) Temperature differences between single cells can be kept small.

(2) Maintenance is easy because there are no moving parts.

(3) When a heat storage material is used, heat transfer between the cell and the heat storage material becomes easier, making it more effective.

[Brief explanation of the drawing]

FIG. 1 is an explanatory plan cross-sectional view showing an example of the sodium-sulfur battery of the present invention, FIG. 2 is an explanatory cross-sectional view taken along the line A-A in FIG. 1, and FIG. ), FIG. 4 is a schematic diagram showing the change in battery temperature during one cycle in Example 1, and FIG. 5 is a schematic diagram showing the change in battery temperature during one cycle in Example 2. The schematic diagram shown in FIG. 6 is a schematic diagram showing the change in battery temperature during one cycle in the conventional method. 1... Sodium-sulfur cell, 2... Heat retention furnace,
3...Insulating material, 4.8...Heat pipe, 5...
Heat dissipation section, 6... Other furnace, 7... Radiation heat receiving plate, 10.
... Valve, 11... Internal heat equalizing plate, 12... Sub module case, 13... External heat equalizing plate, 14... Insulating material, 15... Wiring, 16... Heat storage material, 17...box

Claims (1)

[Claims] 1. A heat pipe for keeping the temperature within a certain range is placed in a heat insulating furnace that houses sodium-sulfur cells, and the heat pipe is thermally connected to a heat dissipation section provided outside the heat insulating furnace. Sodium-sulfur battery.