Fan drive method

Abstract

It drives a fan located within the battery pack without affecting drivability or increasing the size of the ECU. [Solution] The system detects the temperature of the cooler 11 that cools the cell group 10 located inside the battery pack P1, and also detects the temperature of a high-temperature area different from the cell group 10, from a thermoelectric element 14. The cooler temperature and the high-temperature area temperature are obtained from these thermoelectric elements, and based on the temperature difference, a fan 13 located inside the battery pack P1 is started, and the airflow of the fan 13 is adjusted according to the temperature difference.

Description

Technical Field

[0001] The present disclosure relates to a fan driving method.

Background Art

[0002] The battery pack described in Patent Document 1 below has a plurality of unit cells housed in a sealed internal space and is supposed to be able to efficiently cool the housed unit cells. To solve this problem, an insertion hole that communicates the internal space and the external space outside the case is formed in the case, and the rotating shaft of the motor is inserted and arranged in the insertion hole. Since the motor drives an internal fan arranged in the internal space of the case, the air in the internal space can be circulated by the internal fan to cool each cell. Further, since the rotating shaft is arranged through the insertion hole, an external fan can be provided on the rotating shaft protruding from the case to the outside. Thus, by using one motor, fans can be provided not only inside the case but also outside the case to cool from the outside of the case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the power to drive the fan must be supplied each time from the power used to drive the vehicle. Therefore, the operation of the fan affects drivability. A temperature sensor is required for fan control, which increases the cost of adding the temperature sensor. The control logic for turning the fan ON / OFF needs to be incorporated into the ECU (Electronic Control Unit), making the ECU's control circuitry more complex. Such additions increase the size of the ECU board, and an additional connector is needed to connect the fan to the ECU, thus increasing the size of the ECU itself.

[0005] This disclosure aims to drive a fan located within a battery pack without affecting drivability or increasing the size of the ECU. [Means for solving the problem]

[0006] This disclosure relates to a fan driving method, wherein a thermoelectric element detects the temperature of a cooler that cools a group of cells provided in a battery pack, and also detects the temperature of a high-temperature area that is different from the group of cells, obtains the temperature difference between the cooler temperature and the high-temperature area temperature, starts a fan provided in the battery pack based on the temperature difference, and adjusts the airflow of the fan according to the temperature difference. [Effects of the Invention]

[0007] According to this disclosure, it is possible to drive a fan located within the battery pack without affecting drivability or increasing the size of the ECU. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing the configuration of the battery pack according to this embodiment. [Figure 2] Figure 2 is a schematic diagram showing the configuration of a modified battery pack. [Figure 3] Figure 3 is a schematic diagram showing the configuration of a modified battery pack. [Modes for carrying out the invention]

[0009] This embodiment will be described below with reference to the attached drawings. To facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing whenever possible, and redundant explanations are omitted.

[0010] The battery pack P1 shown in Figure 1 is installed in electric vehicles that require a large battery pack, such as battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs). When the battery pack P1 is installed in a plug-in hybrid vehicle, for example, it becomes hot due to heat from the vehicle (radiant heat from the exhaust pipe, hot air from the engine compartment). The battery pack P1 may also experience internal thermal interference due to the heat generated by the internal components. For example, the ambient temperature outside the battery pack P1 is assumed to be approximately 90°C.

[0011] The battery pack P1 according to this embodiment is provided with a cell group 10, a cooler 11, a device 12, a fan 13, and a thermoelectric element 14. The cell group 10 is composed of multiple batteries. The cooler 11 is a cooler for cooling the cell group 10. In this embodiment, the temperature of the cooler 11 is approximately 20°C. The device 12 is a device provided in the battery pack P1. The fan 13 is a fan for circulating air inside the battery pack P1.

[0012] The thermoelectric element 14 is positioned such that one side is in contact with the inner circumferential wall of the battery pack P1 and the other side is in contact with the cooler 11. The thermoelectric element 14 is an element that generates an electromotive force when one side is heated and the other side is cooled, creating a temperature difference due to the Seebeck effect. For example, using a thermoelectric element 14 with dimensions of 2 cm x 2 cm, a maximum power of 2 W can be obtained with a temperature difference of 70°C (external ambient temperature 90°C - cooler temperature 20°C). Since the power required to drive the fan 13 is 0.5 W, the fan 13 can be driven by the thermoelectric element 14.

[0013] The electromotive force generated by the thermoelectric element 14 increases as the temperature difference increases and decreases as the temperature difference decreases. Therefore, when the ambient temperature outside the battery pack P1 increases, the temperature difference increases, which increases the electromotive force generated by the thermoelectric element 14, increases the power supplied to the fan 13, and increases the rotation speed of the fan 13, thereby increasing the airflow.

[0014] As shown in Figure 2, the modified battery pack P2 is an example in which a highly heat-generating device 15 is provided in addition to the device 12 within the battery pack P2. The battery pack P2 is equipped with a cell group 10, a cooler 11, device 12, a fan 13, device 15, and a thermoelectric element 16. When the battery pack P2 is installed in a BEV, for example, there is no exhaust heat from the engine so the external ambient temperature does not rise, but it is necessary to deal with the heat generated by the device 15.

[0015] The heating temperature of the device 15 is, for example, 110°C. The thermoelectric element 16 is positioned so that one side is in contact with the device 15 and the other side is in contact with the cooler 11. The thermoelectric element 16 is an element that generates an electromotive force when one side is heated and the other side is cooled, creating a temperature difference, due to the Seebeck effect.

[0016] As shown in Figure 3, the modified battery pack P3 combines the configuration of battery pack P1 and the configuration of battery pack P2. Battery pack P3 is equipped with a cell group 10, a cooler 11, equipment 12, a fan 13, a thermoelectric element 14, equipment 15, and a thermoelectric element 16.

[0017] The thermoelectric element 14 is arranged such that one surface contacts the inner peripheral wall of the battery pack P1 and the other surface contacts the cooler 11. The thermoelectric element 16 is arranged such that one surface contacts the device 15 and the other surface contacts the cooler 11. By configuring in this way, the fan 13 is driven by the electromotive force generated by the thermoelectric element 14 and the thermoelectric element 16.

[0018] As described above, the present embodiment has been described with reference to specific examples. However, the present disclosure is not limited to these specific examples. Those obtained by appropriately making design changes by those skilled in the art to these specific examples are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the above-described specific examples and its arrangement, conditions, shape, etc. are not limited to those illustrated and can be changed as appropriate. Each element included in each of the above-described specific examples can be appropriately combined as long as no technical contradiction occurs.

[0019] [Appendix] [Appendix 1] The cooler temperature, which is the temperature of the cooler 11 that cools the cell group 10 provided in the battery packs P1, P2, P3, is detected, and the thermoelectric elements 14, 16 that detect the temperature of the high-temperature part, which is the temperature of a part different from the cell group 10, obtain the temperature difference between the cooler temperature and the high-temperature part temperature, and based on the temperature difference, start the fan 13 provided in the battery packs P1, P2, P3, and adjust the air volume of the fan 13 according to the temperature difference.

[0020] In the case of the battery pack P1, for example, since it is mounted on a plug-in hybrid vehicle, it becomes in a high-temperature state due to heat from the vehicle side (radiant heat from the exhaust pipe, hot air from the engine compartment), so the high-temperature part is the outer part of the battery pack P1. In the case of the battery pack P2, for example, since it is mounted on a BEV, there is no exhaust heat from the engine, so the external ambient temperature does not increase, but since the device 15 generates high heat, the high-temperature part is the device 15. In the case of the battery pack P2, the high-temperature parts are the outer part of the battery pack P1 and the device 15.

[0021] According to Supplementary Note 1, the thermoelectric elements 14, 16 obtain the temperature difference between the cooler temperature and the high-temperature part temperature, and based on the temperature difference, start the fans 13 provided in the battery packs P1, P2, P3, and adjust the air volume of the fans 13 according to the temperature difference. Therefore, there is no need to provide an ECU for driving and controlling the fans 13, and there is no need to incorporate the control logic for driving and controlling into the ECU. There is no need to cover the power for driving the fans 13 from the power for driving the vehicle. The driving of the fans 13 does not affect the drivability performance. A temperature sensor is not required for fan control.

Explanation of Signs

[0022] P1, P2, P3: Battery packs 10: Cell group 11: Cooler 12: Equipment 13: Fan 14: Thermoelectric element 15: Equipment 16: Thermoelectric element

Claims

[Claim 1] A thermoelectric element detects the temperature of a cooler that cools a group of cells within a battery pack, and also detects the temperature of a high-temperature area that is different from the group of cells, and acquires the temperature difference between the cooler temperature and the high-temperature area temperature. Based on the aforementioned temperature difference, the fan provided in the battery pack is started. A fan drive method that adjusts the airflow of the fan according to the temperature difference.

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