JP2022103833A - Heat insulation cover for power storage system - Google Patents

Abstract

To provide a heat insulation cover for a power storage system which does not suppress the charging and discharging of a battery cell inside the power storage system even when the outside temperature is below freezing.SOLUTION: A heat insulation cover 100 according to the present invention that can be attached to the outside of a power storage system having a battery cell has a heater structure 20 that can maintain the temperature inside the heat insulation cover 100 at temperature higher than 0°C.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat insulating cover that can be attached to the outside of a power storage system having a battery cell, and more particularly to a heat insulating cover for a power storage system that enables charging and discharging of the power storage system below the freezing point.

As a power storage system, there is a power storage system for a house, that is, a general household. In a residential power storage system, for example, as shown in Patent Document 1 and Patent Document 2, the box body constituting the power storage system is generally arranged outdoors.

Residential power storage systems are usually set to suppress charging and discharging in order to protect the performance of the battery cells when the temperature of the battery cells inside the power storage system reaches 45 ° C. or higher or below freezing point.

FIG. 5 shows the above-mentioned observation records for each observation site from August 1, 2019 to April 16, 2020 at 914 observation sites (municipalities) where the temperature is measured among the observation stations of the Meteorological Agency. It is a graph which aggregated the daily minimum temperature of the period. From Fig. 5, 93% of the observation sites have a daily minimum temperature higher than -15 ° C, 5% of the observation sites have a daily minimum temperature of -15 ° C or higher and a daily minimum temperature of -20 ° C or higher, and the daily minimum temperature. However, it can be seen that 2% of the observation sites are below -20 ° C.

Japanese Unexamined Patent Publication No. 2010-182541 Japanese Unexamined Patent Publication No. 2012-9309

The present invention has been made based on the above-mentioned circumstances, and provides a heat insulating cover for a power storage system in which charging / discharging of a battery cell inside the power storage system is not suppressed even when the outside temperature is below freezing point. The purpose.

In order to solve the above problems, first, the present invention is a heat insulating cover that can be attached to the outside of a power storage system having a battery cell, and a heater that can maintain the temperature inside the heat insulating cover at a temperature higher than 0 ° C. Provided is a heat insulating cover for a power storage system having a structure (Invention 1).

According to the present invention (Invention 1), by providing the heater structure, the temperature inside the heat insulating cover for the power storage system can be maintained at a temperature higher than 0 ° C., so that the temperature of the battery cell inside the power storage system is 0 ° C. It can be prevented from becoming the following. Therefore, even if the outside air temperature becomes 0 ° C. or lower, the charging / discharging of the battery cell is not suppressed.

In the above invention (Invention 1), a front portion arranged on the front side of the power storage system, a back portion arranged on the back side of the power storage system, and a right side surface portion arranged on the right side of the power storage system. The heater structure includes a left side surface portion arranged on the left side surface side of the power storage system, an upper surface portion arranged on the upper surface side of the power storage system, and a bottom surface portion arranged on the bottom surface side of the power storage system. However, it is preferable that the front surface portion, the back surface portion, the right side surface portion, the left side surface portion, the upper surface portion, and the bottom surface portion are provided at least one (Invention 2).

According to the present invention (Invention 2), since the heater structure is provided on at least one of the inner surfaces of the heat insulating cover, the temperature inside the heat insulating cover can be efficiently maintained at a temperature higher than 0 ° C. can.

In the above invention (Invention 2), it is preferable that the heater structure is provided at least on the front surface portion and the back surface portion, or on the right side surface portion and the left side surface portion (Invention 3).

According to the present invention (Invention 3), among the inner surfaces of the heat insulating cover, at least the facing front surface portion and the back surface portion or the facing right side surface portion and the left side surface portion are provided with the heater structure more efficiently. The temperature inside the heat insulating cover can be maintained at a temperature higher than 0 ° C.

In the above invention (Invention 1-3), the heater structure includes a heater, a heat conductive member heated by the heater, and a thermostat that senses the temperature inside the heat insulating cover, and the thermostat is the thermostat. It is preferable to control the heater to be turned on when the temperature inside the heat insulating cover reaches 5 ° C. and to be turned off when the temperature inside the heat insulating cover reaches 11.5 ° C. (Invention 4).

According to the present invention (Invention 4), the thermostat can control the temperature inside the heat insulating cover so as not to be 0 ° C. or lower, and can prevent an excessive heating state from being reached, so that high safety is achieved. Can be secured.

According to the heat insulating cover for a power storage system of the present invention, the temperature inside the heat insulating cover for a power storage system can be maintained at a temperature higher than 0 ° C. by providing the heater structure, so that the temperature of the battery cell inside the power storage system can be increased. It is possible to prevent the temperature from falling below 0 ° C. Therefore, even if the outside air temperature becomes 0 ° C. or lower, the charging / discharging of the battery cell is not suppressed.

It is a schematic perspective view which shows the heat insulation cover for a power storage system which concerns on one Embodiment of this invention, (a) is a view seen from the front panel side, (b) is the state which removed the front panel in (a). It is a figure which shows. It is a schematic diagram which shows an example of the heater structure provided in the heat insulation cover for a power storage system of FIG. It is a schematic diagram which shows the variation of the heat conduction member in the heater structure provided in the heat insulation cover for a power storage system of FIG. It is a graph which shows the result of the low temperature test for the residential power storage system which attached the heat insulation cover for a power storage system which concerns on the present invention on the outside. A graph that summarizes the daily minimum temperature for each observation site during the above period using the observation records from August 1, 2019 to April 16, 2020 at 914 stations of the Meteorological Agency that measure the temperature. Is.

Hereinafter, embodiments of the heat insulating cover for a power storage system of the present invention will be described with reference to the drawings as appropriate. The embodiments described below are for facilitating the understanding of the present invention and do not limit the present invention in any way.

[Power storage system]
First, a power storage system to which the heat insulating cover for the power storage system of the present invention is attached will be briefly described. The heat insulating cover for a power storage system according to the present embodiment is intended for a residential power storage system. The residential power storage system executes control to supply the power stored in the battery cell to the load in the house in the event of a power failure when the power supply from the commercial power supply is stopped.

As a residential power storage system, for example, as shown in Patent Document 2, a battery module containing a plurality of battery cells and a storage case for storing the battery modules are provided, and the charge stored in the battery module is used as AC power. A power storage system that converts to and supplies to the load is common. The storage case has a rectangular cuboid shape with the surface having the largest area as the front portion, and a plurality of rectangular cuboid battery modules are stored in this storage case. The plurality of battery modules can be inserted and removed from the front portion and the side portion of the storage case. Inside the storage case, a control unit that controls conversion to AC power or charging / discharging to the battery module is arranged.

The residential power storage system to which the heat storage system heat insulation cover according to the present embodiment is attached is shown by a broken line in FIG. As shown in FIG. 1, the residential power storage system is provided with a pair of legs facing each other on the left and right at the lower part of a storage case having a rectangular cuboid shape. Since the residential power storage system is supported by the pair of legs, the storage case is not in direct contact with the ground.

[Insulation cover for power storage system]
Next, the heat insulating cover for the power storage system of the present invention will be described in detail with reference to the drawings. 1A and 1B are schematic perspective views showing a heat insulating cover for a power storage system according to the present embodiment, in which FIG. 1A is a view seen from the front panel side, and FIG. 1B is a front panel for convenience in FIG. It is a figure which shows the removed state. In FIG. 1, the portion corresponding to the power storage system to be mounted is shown by a broken line. The heat insulating cover 100 for a power storage system has a substantially rectangular cuboid shape larger than that of the power storage system for a house so that it can be mounted on the outside of the power storage system for a house to be mounted.

The heat insulating cover 100 for a power storage system mainly includes a cover portion 10 having a substantially rectangular cuboid shape and a heater structure 20 capable of maintaining the temperature inside the cover portion 10 at a temperature higher than 0 ° C.

<Cover part>
The cover portion 10 includes a front panel 11 corresponding to the front surface of the residential power storage system, a back panel 12 corresponding to the back surface, a right side panel 13 corresponding to the right side surface, and a left side panel 14 corresponding to the left side surface. A top panel 15 corresponding to the top surface and a bottom panel 16 corresponding to the bottom surface are provided.

In the present embodiment, as shown in FIG. 1, the front panel 11 (or the back panel 12) has the largest surface area among the six panels constituting the cover portion 10. The ratio of the surface area of the front panel 11 (or back panel 12) to the surface area of the right side panel 13 (or left side panel 14) is about 2: 1, which is the size and shape of the residential power storage system to be mounted. It fluctuates according to.

The front panel 11 has an inner front portion 11a arranged on the front side of the residential power storage system. The back panel 12 has a back portion 12a arranged on the back side of the residential power storage system on the inside. The right side panel 13 has an inner right side surface portion 13a arranged on the right side surface side of the residential power storage system. The left side panel 14 has an inner left side surface portion 14a arranged on the side surface side of the residential power storage system. The upper surface panel 15 has an upper surface portion 15a arranged on the upper surface side of the residential power storage system inside. The bottom panel 16 has a bottom surface portion 16a arranged on the bottom surface side of the residential power storage system on the inside.

In the present embodiment, the depth dimension of the top panel 15 is the same as that of the right side panel 13 and the left side panel 14, but the top panel 15 has a depth dimension larger than that of the right side panel 13 and the left side panel 14. , May be slightly protruding to the front side. When the upper surface panel 15 projects to the front side, the portion projecting to the front side functions as an eave, so that the front panel 11 can be prevented from being affected by rainwater.

In the present embodiment, the bottom panel 16 of the cover portion 10 is detachably configured. Therefore, by arranging the bottomless box body from which the bottom panel 16 is removed from the cover portion 10 so as to cover it from above the residential power storage system to be mounted, and then attaching the bottom panel 16, the cover portion 10 is attached. Can be attached to a residential power storage system. The bottom panel 16 is fastened to the bottomless box body using screws. The means for attaching the cover portion 10 to the residential power storage system is not limited to the one using the bottom panel 16 which is detachably configured by screws. For example, the front panel 11 of the cover portion 10 may be configured to be removable by screws, or the front panel 11 and the bottom panel 16 may be configured to be removable by screws.

The material of the cover portion 10 is not particularly limited as long as it is not easily affected by sunlight or rain and wind, and for example, aluminum or an aluminum alloy can be preferably used.

<Heater structure>
The heater structure 20 has a structure capable of maintaining the temperature inside the cover portion 10 at a temperature higher than 0 ° C., and includes a heater power supply (not shown), a heat conductive member 21 heated by the heater power supply, and the inside of the cover portion 10. The thermostat 22 that senses the temperature of the heater structure 20 and the heat insulating material 23 that supports the heater structure 20 are mainly provided.

The heater structure 20 may be provided on at least one of the front surface portion 11a, the back surface portion 12a, the right side surface portion 13a, the left side surface portion 14a, the top surface portion 15a, and the bottom surface portion 16a, which are inside the cover portion 10. That is, the heater structure 20 may be provided only on any one of the inner surfaces of the cover portion 10, or may be provided only on the front surface portion 11a and the back surface portion 12a facing each other, and the right side surface portions facing each other. It may be provided only on the 13a and the left side surface portion 14a. The heater structure 20 may be provided on the front portion 11a, the back portion 12a, the right side surface portion 13a and the left side surface portion 14a, may be provided on the front portion 11a, the back surface portion 12a and the bottom surface portion 16a, and may be provided on the front surface portion 11a. , The back surface portion 12a and the upper surface portion 15a may be provided. The heater structure 20 may be provided on all inner surfaces of the cover portion 10.

In the heat insulating cover 100 for a power storage system according to the present embodiment as shown in FIG. 1, since the residential power storage system to be mounted has a leg portion, cold air easily enters the inside of the cover portion 10 from the bottom panel 16 side. Therefore, when the residential power storage system to be mounted has legs, it is preferable that the heater structure 20 is provided on the bottom surface portion 16a. Further, in the heat insulating cover 100 for a power storage system according to the present embodiment as shown in FIG. 1, the front panel 11 (or the back panel 12) has the largest surface area. Therefore, it is more preferable that the heater structure 20 is provided on the front surface portion 11a and the back surface portion 12a having the largest surface area in addition to the bottom surface portion 16a.

FIG. 1B shows a state in which the heater structure 20 is provided on the back surface portion 12a of the cover portion 10. Hereinafter, the heater structure 20 will be described by taking as an example the heater structure 20 provided on one of the inner surfaces of the cover portion 10 as in the back surface portion 12a of FIG. 1 (b).

FIG. 2 is a schematic view showing an example of a heater structure 20 provided on one of the inner surfaces of the cover portion 10 (hereinafter, referred to as an inner side surface portion). The heater structure 20 is a structure in which a heat conductive member 21 and a thermostat 22 connected to the heat conductive member 21 are embedded in a heat insulating material 23 having an outer shell having substantially the same size as the inner side surface portion. The heat conductive member 21 is connected to a heater power supply (not shown).

(Insulation material)
The heat insulating material 23 is a plate-shaped member having an outer shell having substantially the same size as the inner side surface portion of the cover portion 10 and supporting the heater structure 20. The heat insulating material 23 may have a groove corresponding to the arrangement of the heat conductive member 21 described later. Further, the heat insulating material 23 may have an outer shell having substantially the same size as the inner side surface portion of the cover portion 10, and may be, for example, a combination of a plurality of heat insulating materials. In the present embodiment, the heat insulating material 23 is a polypropylene foam, but is not limited to this as long as it has heat insulating performance. The heat insulating material 23 may be, for example, a lightweight foamed ceramic material. The heat insulating material 23 can be fixed to the inner side surface portion of the cover portion 10 by using an adhesive means such as double-sided tape or an adhesive.

The thickness of the heat insulating material 23 can be appropriately set according to the size of the cover portion 10, the thickness of the heat conductive member 21, and the like.

(Heat conduction member)
In the present embodiment, the heat conductive member 21 is a silicone cord heater in which a heating wire is spirally wound around a glass string and coated with heat-resistant silicone rubber. Silicone cord heaters are suitably used for the heater structure 20 because they have excellent flexibility and high electrical insulation. As shown in FIG. 2, the silicone cord heater as the heat conductive member 21 is embedded in the heat insulating material 23 adhered to the inner side surface portion of the cover portion 10. As long as the heat conductive member 21 is embedded over the entire heat insulating material 23, its position and installation shape are not particularly limited, but it may be embedded in a shape corresponding to the arrangement of the battery cells inside the power storage system. More preferred.

For example, a short, long, high-power heater such as a sheathed heater tends to raise its temperature locally. On the other hand, since the silicone cord heater has a low wattage per unit length, the local temperature rise can be suppressed by using a relatively long heater, so that the object can be heated evenly. Therefore, as the heat conductive member 21, a silicone cord heater is preferable.

In the present embodiment, the heat conductive member 21 is a linear silicone cord heater, but the heat conductive member 21 has a structure that can be planarly embedded in the heat insulating material 23 adhered to the inner side surface portion of the cover portion 10. It is not limited to a linear heater. For example, the heat conductive member 21 may be a planar film heater. Further, as the linear heater, a ribbon heater, a silicon belt heater or a heater cable can be used in addition to the silicone cord heater. If a fan heater or a battery heater is used as the heater structure 20, the heat insulating cover 100 for the power storage system becomes large. In the present embodiment, by using the heat conductive member 212 that can be installed flatly on the inner side surface portion of the cover portion 10 as the heater structure 20, it is possible to avoid increasing the size of the heat insulating cover 100 for the power storage system.

For example, as shown in FIG. 1B, the heat conductive member 21 is arranged in a shape reciprocating between the upper end and the lower end of the heat insulating material 23, so that the heat conductive member 21 is embedded over the entire heat insulating material 23. As shown in FIG. 2, it is a hand shape embedded throughout the heat insulating material 23 by being arranged in a shape facing the center line of the heat insulating material 23. You may. FIG. 3 is a schematic view showing variations of the heat conductive member 21 in the heater structure 20. In FIG. 3, for convenience, only the heat insulating material 23 and the heat conductive member 21 embedded in the heat insulating material 23 are shown. The heat conductive member 21 may have a shape in which an S-shape is connected as shown in FIG. 3A, or a shape in which a W-shape is connected as shown in FIG. 3B. It may be concentric as shown in FIG. 3 (c), it may be concentric as shown in FIG. 3 (d), it may be an opposed hand shape as shown in FIG. 3 (d), or it may be in the shape of an opposing hand. It may be in a grid pattern as shown in FIG. 3 (f), in a horizontal zigzag shape as shown in FIG. 3 (f), or in a vertical zigzag shape as shown in FIG. 3 (g). It may have a shape, or may have a plurality of linear shapes as shown in FIG. 3 (h).

(thermostat)
In the present embodiment, the thermostat 22 controls to turn on the heater power when the temperature inside the cover portion 10 reaches 5 ° C. and turn off the heater power when the temperature inside the cover portion 10 reaches 11.5 ° C. The thermostat 22 can control the temperature inside the cover portion 10 so as not to be 0 ° C. or lower, and can prevent an excessive heating state from being reached, so that high safety can be ensured. As the thermostat 22, a thermostat for mechanical detection using a bimetal, a shape memory alloy, or the like is preferable to be incorporated in the heater structure 20. In this embodiment, the thermostat 22 is connected to the heat conductive member 21, but it is also possible to use a thermostat in which a temperature sensor is built in the heater structure 20 and the set temperature is controlled by an external controller. The thermostat 22 is not limited to that of the present embodiment as long as the temperature inside the cover portion 10 can be controlled so as not to be 0 ° C. or lower. For example, the thermostat 22 may be controlled to turn on the heater power when the temperature inside the cover portion 10 reaches 5 ° C. and turn off the heater power when the temperature inside the cover portion 10 reaches 11.5 ° C.

[How to use the heat insulation cover for the power storage system]
Next, a method of using the heat insulating cover 100 for a power storage system described above will be described.

First, by removing the front panel 11 once, the heat insulating cover 100 for the power storage system is attached to the outside of the power storage system for a house. At this time, the front surface portion 11a is on the front side of the power storage system, the back surface portion 12a is on the back surface side, the right side surface portion 13a is on the right side surface side, the left side surface portion 14a is on the left side surface side, and the top surface portion 15a is on the top surface side. The bottom surface portions 16a correspond to each other. At this time, the temperature inside the heat insulating cover 100 for the power storage system is set to 5 ° C.

When the outside air temperature drops and the temperature inside the heat insulating cover 100 for the power storage system reaches 5 ° C., the thermostat 22 detects this and controls to turn on the heater power. As a result, the temperature inside the heat insulating cover 100 for the power storage system is prevented from becoming 0 ° C. or lower, so that the outside air temperature is below the freezing point and the charging / discharging of the battery cell inside the power storage system is not suppressed. When the outside air temperature rises and the temperature inside the heat insulating cover 100 for the power storage system reaches 11.5 ° C., the thermostat 22 detects this and controls to turn off the heater power. As a result, it is possible to prevent the inside of the heat insulating cover 100 for the power storage system from reaching an excessively heated state, so that high safety is ensured.

As described above, according to the heat storage system heat insulating cover 100 according to the present embodiment, the temperature inside the power storage system heat insulating cover 100 can be maintained at a temperature higher than 0 ° C., so that the temperature of the battery cell inside the power storage system can be maintained. Can be prevented from falling below 0 ° C. Therefore, even if the outside air temperature becomes 0 ° C. or lower, the charging / discharging of the battery cell is not suppressed.

Although the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment, and various modifications can be made. In the above embodiment, the heat insulating cover 100 for a power storage system has a substantially rectangular shape according to the shape of the power storage system for a house to be mounted, but the shape of the heat insulating cover 100 for a power storage system is a power storage for a house. The shape corresponds to the shape of the system, and is not limited to the above-mentioned shape as long as it has a heater structure on at least one of the inner surfaces thereof. Further, if the heat insulating cover 100 can be provided with a separate installation space, a switchboard heater or the like in which a thermostat and a heater function are integrated can be used as the heater structure.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

A low temperature test at an outside air temperature of −20 ° C. and 72 hours was performed on a residential power storage system having a heat storage system heat insulating cover 100 mounted on the outside. The test results are shown in FIG. FIG. 4 shows the temperature of the internal space of the low temperature test tank (° C), the temperature of the upper battery cell (° C), the temperature of the lower battery cell (° C), and the temperature of the internal space of the storage power system (° C), respectively.

From FIG. 4, it can be seen that by attaching the heat insulating cover 100 for the power storage system, the temperature inside the power storage system was stably maintained at 0 ° C. or higher for 72 hours.

The present invention is particularly useful for winter use of residential power storage systems.

100 Insulation cover for power storage system 10 Cover part 11 Front panel 11a Front part 12 Back panel 12a Back part 13 Right side panel 13a Right side part 14 Left side panel 14a Left side part 15 Top panel 15a Top part 16 Bottom panel 16a Bottom part 20 Heater structure 21 Heat conductive member 22 Thermostat 23 Insulation material

Claims (4)

A heat insulating cover that can be attached to the outside of a power storage system that has a battery cell.
A heat insulating cover for a power storage system having a heater structure capable of maintaining the temperature inside the heat insulating cover at a temperature higher than 0 ° C. The front part arranged on the front side of the power storage system and the front part
The back portion arranged on the back side of the power storage system and
The right side surface portion arranged on the right side surface side of the power storage system and
The left side surface portion arranged on the left side surface side of the power storage system and
The upper surface portion arranged on the upper surface side of the power storage system and the upper surface portion.
A bottom surface portion arranged on the bottom surface side of the power storage system is provided.
The heat insulating cover for a power storage system according to claim 1, wherein the heater structure is provided on at least one of the front surface portion, the back surface portion, the right side surface portion, the left side surface portion, the top surface portion, and the bottom surface portion. The heat insulating cover for a power storage system according to claim 2, wherein the heater structure is provided at least on the front surface portion and the back surface portion, or on the right side surface portion and the left side surface portion. The heater structure has a heater power supply, a heat conductive member heated by the heater power supply, and a thermostat that senses the temperature inside the heat insulating cover.
Claims 1 to 3 control the thermostat to turn on the heater power when the temperature inside the heat insulating cover reaches 5 ° C. and turn off the heater power when the temperature inside the heat insulating cover reaches 11.5 ° C. The heat insulating cover for a power storage system according to any one of the above items.

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