JPS63143760A - Sodium-sulfur battery - Google Patents

Abstract

PURPOSE:To maintain a quantity of heat within a definite temperature by providing a case inside a heat reserving furnace, wherein unit batteries are contained in many recessed parts, which are partly immersed in a sealed heat medium, equipped with a cooler outside the heat reserving furnace in order to thermally connect the case with the cooler. CONSTITUTION:A heat medium 5 is sealed immersing partly recessed parts 3 inside a case 4 and a cooler 6 is provided outside a heat reserving furnace 1. The case 4 and the cooler 6 are connected with piping 10 equipped with control valves 7, 8. On a liquid phase 11 of the heat medium, a temperature controller 12 is mounted, by which said control valve 7 is actuated. With the bottom of the cooler 6, a tube 13 containing a liquid is connected forming a circuit head. The lower part of the tube 13 and the liquid phase part of heat medium 11 are connected with piping 15 equipped with a valve 14. A heater 16 used for start-up is connected with piping 10 through a valve 17 and piping 15 through a valve 18. By the arrangement, a considerable quantity of heat can be transferred with a small temperature difference.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat medium type sodium fluoride battery that can maintain charge, discharge, and rest modes within a certain temperature range. .

[Conventional technology]

In sodium-sulfur storage batteries used for power storage, the amount of heat generated changes depending on charging, discharging, and resting modes. However, for proper operation, the temperature must be maintained within a certain range throughout all modes.

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.

[Problem that the invention seeks to solve]

However, the above conventional method has the following problems.

(1) Since the amount of convective heat transfer to the air flow is not that large,
Non-uniform temperatures due to the effects 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 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 device.

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

(5) Scale amplifiers are difficult because it is difficult to theoretically predict airflow.

The present invention was made in view of the above points, and an object of the present invention is to provide a sodium-sulfur battery that maintains a temperature within a certain range by evaporating and condensing a heat medium.

[Means for solving problems]

In the sodium-sulfur battery of the present invention, a case having a large number of recesses for housing the cells is provided in a heat insulating furnace for the sodium-sulfur battery, and a heat medium is placed in the case so that the liquid soaks at least a portion of the recesses. is enclosed, a heat radiating section is provided outside the insulating furnace, and the case and the heat radiating section are thermally connected.

In the present invention, as the heat radiating section, a cooler that cools and condenses the heat medium vapor, a heat pipe heat radiating section, etc. are used. Further, as the heat medium, heat medium oil or the like is used.

[Effect]

When the amount of heat generated by the battery is large, the heat radiating part outside the heat insulating furnace is thermally connected to the inside of the case to cool the inside of the insulating furnace. Cut off.

〔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.

Embodiment 1 In FIG. 1, reference numeral 1 denotes a heat insulating furnace for a sodium-sulfur battery, and the insulating furnace 1 has a number of recesses 3 in which cells 2 are housed.
A case 4 is provided. A heating medium 5 is sealed in the case 4 so that the liquid partially immerses the recess 3. In addition, the heat retention furnace 1
A cooler 6 is provided outside the case 4, and the case 4 and the cooler 6 are connected by a pipe 10 equipped with a control valve 7 and a valve 8. A temperature controller 12 is connected to the heat medium liquid phase portion 11, and the temperature controller 12 is configured to open and close the control valve 7. A cylinder 13 containing a liquid is connected to the lower part of the cooler 6 to form a circulation head, and the lower part of the cylinder 13 and the heat medium liquid phase part 11 are connected by a pipe 15 equipped with a valve 14. ing. 16 is a heater for the start amplifier, which is connected to the pipe 10 via a valve 17 and to the pipe 15 via a valve 18. 20 is a heat medium gas phase part, and 21 is a heat insulating wall.

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

In the charge/pause mode, first close the valves 8, 14, 17, and 18 to disconnect the heater 16 and cooler 6 from the system. The liquid level in the case 4 is such that the lower part of the recess 3 is immersed in the liquid.

In the rest mode, the heat capacity of the unit cell 2 is released, and is released into the outside air mainly from the side wall of the heat-retaining furnace 1. Therefore, in the case 4, the recess 3 has a high temperature, and the outer peripheral wall of the case has a low temperature. When the temperature of the outer peripheral wall of the case 4 decreases due to heat radiation from the wall surface of the heat-retaining furnace 1, condensation occurs there and the vapor pressure decreases. As a result, the liquid in contact with the lower part of the recess 3 of the case evaporates, and the lower part of the recess is cooled by latent heat. The amount of heat is transferred from the upper end of the recess to the lower end of the recess by heat conduction within the cell 2 itself and the wall of the recess.

Since the pressure conditions are the same in all recesses, bursts occur evenly. If there is a concave part that is hotter than others, the amount of evaporation in this part is greater than in the other parts, and cooling is preferentially performed here. If there are recesses that are cooler than others, the amount of shots fired there will be lower. In addition, in a recess at a lower temperature (below the equilibrium temperature at that pressure), condensation occurs at the upper end of the recess in contact with the vapor phase, and the recess is heated. In this way, the vapor of the heating medium uniformly cools the recess while transporting heat to the outer peripheral wall of the case. At this time, the case outer wall, steam,
According to the inventor's calculation results, the temperature difference between the recesses may be 1° C. or less. Also, the temperature difference between the upper and lower sides of the recess is 1ff for the material of the recess.
As a result of trial calculations using copper with a thickness of lI11 and a concave portion of 430 mm, the temperature may be 10° C. or less.

In the discharge mode, the valve 8.14 is first opened to communicate between the cooler 6 and the inside of the case 4. The temperature controller 12 is activated to send an amount of steam corresponding to the heat generation amount of the cell 2 from the case 4 to the cooler B. The temperature of cooler O is lower than the temperature of case 4 (and the pressure is also lower. As a result, the liquid level in cylinder 13, which is the lower piping of cooler 6, rises and falls, but cylinder 1
The pressure at the bottom of case 3 is equal to the pressure of the liquid phase in case 4. The cylindrical body 13 is made sufficiently thin so that the rise and fall of this liquid level does not cause the rise or fall of the liquid level inside the case 4. Further, the cylinder body 13 is made sufficiently long to prevent the inside of the cooler 6 from being depressurized and the liquid phase from entering the cooler. This is because if the liquid level is within the cooler, the liquid will reduce the condensation turnover.

According to the inventor's calculations, the temperature distribution in the discharge mode is as follows. That is, the case outer wall, steam,
The temperature difference between the recesses may be approximately 1° C. or less, the temperature difference within the case and the cooler may be approximately 20° C., and the temperature difference between the upper and lower portions of the recess may be approximately 10° C.

At the time of start amplifier, the valves 17 and 18 are opened to evaporate the heat medium in the heater 16, and the vapor is condensed in the case 4 to perform heating.

Next, a sodium-sulfur battery was designed and prototyped as described below.

Battery capacity 0.54-H batteries x 890 Calorific value When all batteries are discharged 7000Kcal / II when charged 700Kcal / H Furnace shape Inside of main body Length 2.34m x Width 1.34m x Height 1.0
8m Body external dimensions Length 2.75m x Width 1.74m x Height 1
．． Thermal conductivity of the wall of the 48m body: 0.03Kcal
/ mH℃ Heat capacity of main body 770 Kca
l/'C condenser Buddhist painting 0.5M Case outside shape Length 2.34m x Width 1.34m x Height 0.4
3m recess 78.5mm diameter x 430mm length
x 1 mm thick (made of copper) is stacked in two stages in the furnace.
(Registered Trademark) Amount of hold amplifier in the case 150 kg/l Case (liquid depth 220 mm) Cooler circulation flow N Required head for 100 kg/H circulation 0.3 m The operating mode, temperature, and pressure changes of the above sodium-sulfur battery are as follows. It was as shown in Figure 2.

In addition, as a result of trial calculations of the required amount of heat dissipation and the temperature difference required to transfer the amount of heat transfer in the furnace through evaporation and condensation heat transfer, the temperature difference between different batteries was less than 1°C in all modes, and the temperature difference between the top and bottom of one battery was 1°C or less in all modes. It was found that the temperature difference was about 10° C. during discharge, and less than that in other modes.

Note that the allowable value for the upper and lower temperature difference is greater than the allowable value for the temperature difference between different batteries.

Embodiment 2 In FIG. 3, reference numeral 1 denotes a heat insulating furnace for a sodium-sulfur battery, and a large number of recesses 3 in which cells 2 are housed in the heat insulating furnace 1.
A case 4 is provided. A heating medium 5 is sealed in the case 4 so that the liquid partially immerses the recess 3. A heater 2 for starting is installed in the space 22 between the bottom of the case 4 and the bottom of the heat retention furnace 1.
3 is provided, and a space 2 between the upper part of the case 4 and the upper part of the heat retention furnace 1 is provided.
4 is provided with a heat pipe radiation heat receiving section 25, and this heat receiving section 2
5, and a heat vibrator heat dissipation section 2 provided outside the heat retention furnace.
6 through a control valve 27 for blocking and communicating heat flow. A temperature controller 12 is connected to the heat medium gas phase section 20, and the temperature controller 12 is configured to open and close the control valve 27. 11 is a heat medium liquid phase part.

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

In the charge/pause mode, the operation of the charge/pause mode in which the valve 27 is closed and the heat source of the heater is stopped is the same as in the first embodiment.

In the discharge mode, first, the control valve 27 is opened to thermally communicate the heat pipe heat dissipating section 26 and the heat pipe radiation heat receiving section 25, so that the temperature of the heat receiving section 25 is lower than that of other parts in the furnace. do. The amount of heat is transferred by radiation from the upper part of the case side wall, the ceiling wall (heat medium vapor contact part), and the upper part of the unit cell 2 itself to the heat vibe radiation heat receiving part 25. In the trial design example, the temperature difference between the case 4 and the heat vibe radiation heat receiving section 25 is 50°C. The heat medium evaporates at the liquid phase contact portion within the case 4, and condenses at the vapor contact portion, thereby maintaining a uniform temperature within the case. The temperature difference between the evaporation section and the condensation section is 2
It is about ℃.

At startup, the bottom surface of the case is heated by the heater 23.

Next, the recess 3 of the case and the outer peripheral wall of the case are made of the same material (
A sodium-sulfur battery was designed, with a copper cylinder for vertical heat conduction placed around the cell 2 in the recess, and the specifications of the furnace body and case other than those described above being the same as in Example 1. I made a prototype. Heat pipe radiation heat receiving section 25
The area of was 1Od.

The operating mode, temperature, and pressure changes were as shown in Figure 2.

Examples 3 to 5 As shown in FIG. 4, a metal cylinder 28 for vertical heat transfer is provided around the cell 2 in the recess 3 of the case 4, and as shown in FIG. In the recess 3, the outside of the unit cell 2 is filled with a non-conductive thermal conductor 30 such as sand or small glass particles, or a wire mesh or ceramic porous is placed inside the case 4 outside the recess as shown in FIG. A porous material 31 such as wool or wire wool is provided. In the case of Fig. 4 and Fig. 5, the heat transfer in the vertical direction is carried out smoothly, and the
In the case shown in the figure, even if the liquid level of the heating medium falls, the heating medium rises through the inside of the porous body 31, producing the same effect as when the liquid level submerges a part of the recess 3. 4 to 6 can also be used in combination with each other. The other configurations and operations are the same as in the first embodiment or the second embodiment.

〔Effect of the invention〕

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

fl+ Since evaporation and condensation heat transfer are utilized, the temperature difference between various parts in the furnace is small, and a sufficient amount of heat can be transmitted with this small temperature difference.

(2) The temperature inside the furnace has self-equilibrium and is uniform.

(3) In the invention shown in Example 1, the circulation of the heating medium is as follows:
It is carried out by utilizing the difference in specific gravity between liquid and steam, and no power is required, so it is also possible to install a turbine to recover the power.

(4) When furnace insulation is required in rest/charging mode,
It is easy to thermally separate additional items such as heat radiating parts and heaters. Note that with air circulation type, heat is radiated around the air intake even when cooling air is not required.

(5) Future system expansion, such as adding a heat storage device, is easy.

(6) If the heating medium is selected appropriately, the entire system can be operated under reduced pressure.
Equipment inspection and maintenance can be performed easily.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram showing one embodiment of the sodium-sulfur battery of the present invention, and FIG. 2 shows the operation of the battery shown in FIGS. 1 and 3, and the battery temperature and case internal pressure during one cycle. FIG. 3 is a cross-sectional explanatory diagram showing other embodiments of the sodium-sulfur battery of the present invention, and FIGS.
FIG. 6 is an explanatory diagram showing another example of the cell and the surroundings of the case. 1-Heating furnace, 2-cell, 3-recess, 4-case, 5
-Heating medium, 6-.Cooler, 7-.-Control valve, 8.14.
17.18--Valve, 10.15--Piping, 11--Heating medium liquid phase part, 12--Temperature controller, 13--Cylinder, 16-
-・Heater, 20-heat medium gas phase part, 21・-insulation wall, 2
2.24-・Space, 23-Heater, 25-Heat pipe radiation heat receiving section, 26-・Heat pipe heat radiation section, 27-・
- Control valve, 28... Metal cylinder, 30 - Heat conductor, 3
1.-Porous body

Claims (1)

[Claims] 1. A case having a number of recesses for housing the cells is provided in the insulating furnace for the sodium-sulfur battery, and a heating medium is sealed in this case so that the liquid soaks at least a portion of the recesses, and the outside of the insulating furnace is A sodium-sulfur battery characterized by having a heat dissipating section provided in the casing and thermally connecting the case and the heat dissipating section.