Heating safety evaluation device

Abstract

The problem addressed by the present invention is that of making it possible to evaluate the critical temperature at which a sample is thermally out of control even if there is a cooling means, and to reduce the load on surrounding heating devices. In order to solve the problem, this heating safety evaluation device is provided with a sensor, a heating device, a cooling device, and a control device. The control device repeats a series of predetermined controls. The series of controls are control in which the sample is heated, after which, when spontaneous heating is detected by the sensor, the spontaneous heating is attempted to end by cooling the sample by the cooling device, and at the same time, a pseudo-adiabatic state is formed by heating by the surrounding heating device. The pseudo-adiabatic state is a state in which the amount of heat between the sample cooled by the cooling device and the surroundings thereof is zero. The heating safety evaluation device evaluates the temperature of the sample at which spontaneous heating is not completed during the repetition of the series of control as a critical temperature at which the sample is thermally out of control even if the sample is cooled by the cooling device.

Description

Technical Field

[0001] The present invention relates to a heating safety evaluation device for evaluating the heating safety of a sample. Background Art

[0002] In recent years, electric vehicles such as pure electric vehicles (EV) and hybrid electric vehicles (HEV) have become popular. In these electric vehicles, improving the safety, especially improving the safety of batteries, has become an issue.

[0003] [Prior Technical Literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-18638 Summary of the invention

[0006] [Problems to be solved by the invention]

[0007] A heating safety evaluation device that evaluates the heating safety of a battery or other object mounted on an electric vehicle has the following configuration: the heating safety evaluation device includes a sensor that detects the self-heating of a sample such as a battery, and a surrounding heating device that is configured to heat the surroundings of the sample.

[0008] The heating safety evaluation device heats the sample using a surrounding heating device. Afterwards, when the sensor detects the self-heating of the sample, the surrounding heating device is used to control it to a predetermined pseudo-adiabatic state, and at the same time, the self-heating of the sample is followed up and observed. In addition, the "pseudo-adiabatic state" mentioned here is a state in which the heat balance between the sample and its surroundings is zero.

[0009] According to the above-mentioned heating safety evaluation device, the temperature change of the sample in the adiabatic state can be tracked. Therefore, the self-heating rate of the sample at each temperature can be evaluated. However, the present inventors have noticed the following problems.

[0010] That is, for actual storage batteries, some cooling means of a specified type are often provided at specified locations. It is not possible to evaluate the critical temperature at which the temperature of the sample continues to rise due to self-heating even with these cooling means, that is, the critical temperature at which thermal runaway occurs even with cooling means. Furthermore, when the self-heating of the sample is large, the load on the surrounding heating device when maintaining the pseudo-adiabatic state becomes large.

[0011] Furthermore, the above description has been made taking the case where the evaluation target is a storage battery as an example, but the same problem may occur when the evaluation target is another object.

[0012] The present invention has been made in view of the above circumstances, and an object of the present invention is to enable evaluation of the critical temperature at which a sample will thermally run away even with cooling means, and to reduce the load on the peripheral heating device.

[0013] [Technical means to solve the problem]

[0014] The inventors have found that the above-mentioned object can be achieved by providing a cooling device for cooling the sample and performing a predetermined control, thereby completing the present invention. The present invention is a heating safety evaluation device according to the following (1) to (10).

[0015] (1) A heating safety evaluation device comprising:

[0016] a sensor to detect self-heating of the sample; and,

[0017] A peripheral heating device configured to heat the periphery of the sample;

[0018] Furthermore, the heating safety evaluation device comprises:

[0019] a cooling device configured to cool the sample; and

[0020] A control device that repeatedly performs a prescribed series of controls;

[0021] The aforementioned series of controls is to heat the aforementioned sample, and then, when the aforementioned sensor detects the aforementioned self-heating, the aforementioned sample is cooled by the aforementioned cooling device to try to end the aforementioned self-heating, and at the same time, the aforementioned surrounding heating device is used to heat the sample to form a pseudo-adiabatic state control,

[0022] The pseudo-adiabatic state is a state in which the heat balance between the sample cooled by the cooling device and its surroundings is zero.

[0023] The heating safety evaluation device evaluates the temperature of the sample when the self-heating has not yet ended during the repetition of the series of controls as a critical temperature at which the sample will still experience thermal runaway even if cooled by the cooling device.

[0024] According to this structure, by simulating the configuration and cooling speed of the cooling device to the structure of the actual cooling means, it is possible to evaluate the critical temperature at which the sample will thermally run away even with the cooling means. Furthermore, since the sample is cooled by the cooling device, the temperature rise of the sample caused by the self-heating of the sample is suppressed accordingly. Therefore, the load of the surrounding heating device when maintaining the pseudo-adiabatic state can be reduced accordingly, and the heating safety of the sample with a higher heating speed can be evaluated.

[0025] As described above, according to this configuration, it is possible to evaluate the critical temperature at which a sample will thermally run away even with cooling means, and to reduce the load on the peripheral heating device.

[0026] (2) The heating safety evaluation device according to (1) above, comprising a heating device configured to heat the sample.

[0027] The aforementioned series of controls is to heat the aforementioned sample, and then, when the aforementioned sensor detects the aforementioned self-heating, the aforementioned cooling device cools the aforementioned sample and the aforementioned heating device heats the aforementioned sample, and at the same time, the aforementioned surrounding heating device heats the aforementioned sample to form a pseudo-adiabatic state control,

[0028] The pseudo-adiabatic state is a state in which the heat balance between the sample cooled by the cooling device and heated by the heating device and its surroundings is zero.

[0029] According to this configuration, by providing the heating safety evaluation device with not only the cooling device but also the heating device, the temperature distribution around the sample can be simulated with higher accuracy to the actual temperature distribution.

[0030] (3) The heating safety evaluation device according to (1) or (2), wherein the cooling device includes an element having a heat absorbing surface and a heat generating surface, and cools the sample via the heat absorbing surface.

[0031] According to this configuration, the heat balance of the system including the sample and its surroundings by the cooling device can be made zero.

[0032] (4) The heating safety evaluation device according to any one of (1) to (3), wherein the control device regards the self-heating as completed when the temperature rise rate of the sample is 0.02° C. / min or less.

[0033] Generally, the detection limit of the temperature rise rate is 0.02°C / min. If the temperature is below the detection limit, the self-heating is considered to have ended, so that the evaluation test can be completed with the highest accuracy possible.

[0034] (5) The heating safety evaluation device according to (3) above, wherein the cooling device includes a cooling Peltier element for cooling the sample via the heat absorbing surface, and a cooling circuit for supplying power to the cooling Peltier element.

[0035] The control device controls the cooling device by controlling the cooling circuit.

[0036] According to this configuration, by controlling the current flowing into the cooling Peltier element, the cooling speed of the cooling device can be quantitatively controlled.

[0037] (6) The heating safety evaluation device according to (2) above, wherein the heating device comprises a heating Peltier element for heating the sample by means of a heating surface, and a heating circuit for supplying power to the heating Peltier element.

[0038] The control device controls the heating device by controlling the heating circuit.

[0039] According to this configuration, by controlling the current flowing into the heating Peltier element, the heating speed of the heating device can be quantitatively controlled.

[0040] (7) The heating safety evaluation device according to any one of (1) to (6), wherein a plurality of Peltier elements are provided for the sample.

[0041] According to this structure, by controlling a plurality of Peltier elements, the temperature and temperature distribution of the sample can be controlled with high accuracy, thereby simulating the actual state with higher accuracy.

[0042] (8) The heating safety evaluation device according to (2), wherein the heating device comprises a heating Peltier element for heating the sample by means of a heating surface, and a heating circuit for supplying power to the heating Peltier element.

[0043] The cooling device includes a cooling Peltier element for cooling the sample by means of a heat absorbing surface, and a cooling circuit for supplying power to the cooling Peltier element.

[0044] The heating surface of the heating Peltier element is used to heat a predetermined portion of the sample.

[0045] The other parts of the sample are cooled by the heat absorbing surface of the cooling Peltier element.

[0046] According to this structure, both heating and cooling of the sample can be performed by using a plurality of Peltier elements.

[0047] (9) The heating safety evaluation device according to any one of (1) to (8) above, further comprising a sample container for accommodating the sample.

[0048] The sample container is in a hexahedral shape.

[0049] Many actual containers for storing storage batteries and the like are hexahedral. Therefore, according to this configuration, it is easy to perform a test that simulates an actual container.

[0050] (10) The heating safety evaluation device according to any one of (1) to (8) above, further comprising a sample container for accommodating the sample.

[0051] The sample container is cylindrical.

[0052] Many actual containers for storing storage batteries and the like are cylindrical. Therefore, according to this configuration, it is easy to perform a test that simulates an actual container.

[0053] (Effects of the Invention)

[0054] As described above, according to the structure of (1), the critical temperature at which the sample will thermally run away even with cooling means can be evaluated, and the load on the surrounding heating device can be reduced. Furthermore, according to the structures of (2) to (10) cited from the structure of (1), respective additional effects can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 Schematic diagram showing a heating safety evaluation device according to a first embodiment.

[0056] Figure 2 It is a circuit diagram showing a heating device and a cooling device.

[0057] Figure 3 This is a perspective view showing an example of the arrangement of a sample container and a Peltier element.

[0058] Figure 4 It is a perspective view showing another example of the arrangement of the sample container and the Peltier element.

[0059] Figure 5 This is a flowchart showing the flow of control performed by the control device.

[0060] Figure 6 This is a graph showing the relationship between the sample temperature and the sample's heating rate. DETAILED DESCRIPTION

[0061] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments at all, and can be implemented with appropriate changes within the scope of the present invention.

[0062] [First embodiment]

[0063] like Figure 1 As shown, the heating safety evaluation device 100 of the present embodiment includes a system container 10, a sample container 30, a first sensor 41, a second sensor 42, an ambient heating device 20, a heating device 50, a cooling device 60, a control device 70, and an evaluation device 80. Hereinafter, the first sensor 41 and the second sensor 42 are simply referred to as "sensors 41, 42".

[0064] In the present embodiment, the sample Sp is a storage battery. The sample container 30 contains the sample Sp. The sample Sp preferably abuts against the sample container 30 from the inside. However, in the case where the abutment is impossible, it is preferable to make the sample Sp and the sample container 30 as close as possible. As a case where such abutment is impossible, for example, a case where the peripheral portion of the terminal in the sample Sp cannot abut against the sample container 30 from the inside can be cited because the storage battery as the sample Sp has a protruding terminal. In this case, a heat transfer material is provided between the portion of the sample Sp that cannot abut against the sample container 30 and the sample container 30. The heat transfer material preferably has a sufficiently smaller heat capacity than the sample (for example, less than 1 / 20) and a higher thermal conductivity than the sample.

[0065] The sample container 30 imitates the housing of an intelligent power unit (IPU) that actually carries a battery. However, the present embodiment may be implemented by using the contents of the battery as the sample Sp and the outer packaging of the battery itself as the sample container 30 instead.

[0066] The system container 10 accommodates the sample container 30. A heat insulating material 15 is provided around the system container 10 for heat preservation of the system container 10. The first sensor 41 detects the surface temperature Ta of the sample container 30, and based on the surface temperature Ta, detects the temperature of the sample Sp and the self-heating of the sample Sp. The second sensor 42 detects the ambient temperature Tb of the sample container 30 in the system container 10.

[0067] The heating device 50 is configured to heat the sample Sp. The cooling device 60 is configured to cool the sample Sp. Specifically, the heating device 50 heats the sample Sp by heating the sample container 30. The cooling device 60 cools the sample Sp by cooling the sample container 30. More specifically, Figure 2 As shown in FIG. 1 , the heating device 50 includes a plurality of heating Peltier elements Ph and a heating circuit Ch. The cooling device 60 includes a plurality of cooling Peltier elements Pc and a cooling circuit Cc.

[0068] Each heating Peltier element Ph and each cooling Peltier element Pc are Peltier elements, and have a heat generating surface that generates heat when current flows, and a heat absorbing surface that absorbs heat when current flows. The heat generating surface of each heating Peltier element Ph abuts against the sample container 30. The heat absorbing surface of each cooling Peltier element Pc abuts against the sample container 30. Hereinafter, the heating Peltier element Ph and the cooling Peltier element Pc are referred to as "Peltier elements Ph, Pc".

[0069] The heating circuit Ch is a circuit for supplying power to each heating Peltier element Ph, and is provided with a heating switch SwH. The power source Ps is electrically connected to each heating Peltier element Ph via the heating switch SwH. Therefore, when the heating switch SwH is turned on (ON), each heating Peltier element Ph heats the sample container 30 with the heating surface. Thus, the sample Sp is heated. On the other hand, when the heating switch SwH is turned off (OFF), the heating stops.

[0070] The cooling circuit Cc is a circuit for supplying power to each cooling Peltier element Pc, and is provided with a cooling switch SwC. The power source Ps is electrically connected to each cooling Peltier element Pc via the cooling switch SwC. Therefore, when the cooling switch SwC is turned on (ON), each cooling Peltier element Pc cools the sample container 30 with a heat absorbing surface. Thus, the sample Sp is cooled. On the other hand, when the cooling switch SwC is turned off (OFF), the cooling stops.

[0071] Furthermore, these heating circuits Ch and cooling circuits Cc are configured to quantitatively control the outputs of the Peltier elements Ph and Pc. Specifically, for example, the heating switch SwH and the cooling switch SwC are semiconductor switches, and the duty cycle is controlled. In addition, for example, a semiconductor switch may be provided for each Peltier element Ph and Pc, and the output of each Peltier element Ph and Pc may be quantitatively controlled by controlling the duty cycle of each semiconductor switch.

[0072] Figure 1 The surrounding heating device 20 shown is configured to heat the surrounding of the sample container 30 in the system container 10. The surrounding heating device 20 forms a pseudo-adiabatic state by heating the surrounding of the sample container 30 under a predetermined condition. In addition, the "pseudo-adiabatic state" mentioned here is a state in which the heat balance between the sample Sp heated by the heating device 50 and cooled by the cooling device 60 and its surrounding is zero. In this pseudo-adiabatic state, the surface temperature Ta of the sample container 30 detected by the first sensor 41 and the peripheral temperature Tb of the sample container 30 detected by the second sensor 42 are kept substantially the same.

[0073] The control device 70 controls the surrounding heating device 20, the heating device 50 and the cooling device 60 based on the information from the sensors 41 and 42. Figure 2 As shown, the heating device 50 and the cooling device 60 are controlled, and the surrounding heating device 20 is controlled. The details of the control performed by the control device 70 will be described below.

[0074] Figure 1 The evaluation device 80 shown evaluates the critical temperature Tnr at which the sample Sp will thermally run away based on the temperature change of the sample Sp. In addition, "Tnr" here is an abbreviation of "Temperature of no return". The details of the evaluation performed by the evaluation device 80 will be described below.

[0075] The control device 70 and the evaluation device 80 may be configured by, for example, the same computer or may be configured by different computers.

[0076] Figure 1 The sample container 30 shown can be, for example, Figure 3 The hexahedron shape shown in Figure 4 Specifically, the shape of the sample container 30 may be appropriately modeled after the shape of the housing of an actual IPU as described above.

[0077] Such as these Figure 3 , Figure 4 As shown, a plurality of Peltier elements Ph, Pc are provided in the sample container 30. The configuration and cooling speed of each cooling Peltier element Pc may be simulated by the configuration and cooling speed of each cooling means provided in the housing of an actual IPU. The configuration and heating speed of each heating Peltier element Ph may be simulated by the configuration and heating speed of each heat source provided around the housing of an actual IPU.

[0078] Next, refer to Figure 5 The flowchart of FIG. 1 is used to explain the details of the control performed by the control device 70 and the evaluation performed by the evaluation device 80. In addition, the S before the number mentioned below is an abbreviation of "step". S1 to S5 are performed by the control device 70, and S6 is performed by the evaluation device 80. The control of S1 to S5 can also be renamed as "a series of controls". This series of controls is performed while the sample container 30 is heated by the heating device 50 and the sample container 30 is cooled by the cooling device 60.

[0079] The control device 70 first heats the periphery of the sample container 30 using the periphery heating device 20 in S1, and then waits for a predetermined time in S2, thereby waiting for the heat around the sample container 30 to be transferred to the sample container 30 and the sample Sp.

[0080] In the next S3, it is determined whether the first sensor 41 detects the self-heating of the sample Sp. If a negative determination is made, that is, if the self-heating is not detected, the process returns to S1 and repeats S1 to S3. On the other hand, if a positive determination is made, that is, if the self-heating is detected, the process proceeds to S4.

[0081] In S4, the surroundings of the sample container 30 are heated by the surrounding heating device 20, thereby controlling the sample container 30 to be in a pseudo-adiabatic state. That is, the sample container 30 is controlled so that the heat balance between the sample Sp heated by the heating device 50 and cooled by the cooling device 60 and its surroundings is zero. Then, the sample container 30 is followed up and observed for a period of time.

[0082] In the next S5 , it is determined whether the self-heating of the sample Sp has ended. Specifically, for example, in S5 , it is determined whether the self-heating of the sample Sp has ended before a predetermined time has passed or before the sample Sp has risen to a predetermined temperature.

[0083] In addition, the "end" of self-heating mentioned here means that the temperature rise of the sample Sp caused by self-heating stops. Specifically, in this embodiment, the detection limit of the temperature rise rate of the first sensor 41 is 0.02°C / min. Therefore, if the temperature rise rate of the sample Sp converges to below 0.02°C / min, the control device 70 determines that the self-heating ends.

[0084] If a positive determination is made in S5, that is, if self-heating has ended, the process returns to S1 and S1 to S5 are repeated. On the other hand, if a negative determination is made in S5, that is, if self-heating has not ended, the process proceeds to S6.

[0085] In S6 , the evaluation device 80 evaluates the temperature of the sample Sp when the self-heating is detected in the last S3 as the critical temperature Tnr at which the sample Sp will thermally run away even if cooled by the cooling device 60 .

[0086] Next, refer to Figure 6 , the actions based on the above process are explained. In addition, Figure 6 The vertical axis uses logarithms to represent the heating rate and cooling rate. Figure 6The lower limit of the vertical axis in the figure is 0.02°C / min. Hereinafter, the predetermined temperature is referred to as "first temperature T1", and the predetermined temperatures successively higher than the first temperature T1 are referred to as "second temperature T2", "third temperature T3" and "fourth temperature T4", respectively. In addition, the total cooling rate of the sample Sp by the heating device 50 and the cooling device 60 is referred to as "cooling rate Cr" below. That is, the cooling rate Cr is the cooling rate after the heating by the heating device 50 is offset.

[0087] Here, the case where the self-heating rate SHr and the cooling rate Cr of the sample Sp have the following relationship is used as an example for explanation. The sample Sp starts to self-heat at the first temperature T1. Between the first temperature T1 and the second temperature T2, the self-heating rate SHr of the sample Sp is smaller than the cooling rate Cr. Between the second temperature T2 and the third temperature T3, the self-heating rate SHr of the sample Sp is larger than the cooling rate Cr. Between the third temperature T3 and the fourth temperature T4, the self-heating rate SHr of the sample Sp becomes smaller than the cooling rate Cr again. When the sample Sp becomes higher than the fourth temperature T4, the self-heating rate SHr becomes larger than the cooling rate Cr again. And, above this fourth temperature T4, this magnitude relationship is maintained.

[0088] First, when the temperature of the sample Sp is lower than the first temperature T1, Figure 5 After S1 and S2 shown in the figure, a negative determination is made in S3, that is, self-heating is not detected, and thus S1 to S3 are repeated. By heating in S1 during the repetition of S1 to S3, Figure 6 The temperature of the sample Sp shown on the horizontal axis of rises to a first temperature T1 or higher. As a result, the sample Sp starts to self-heat. However, at this time, since the self-heating rate SHr is lower than the cooling rate Cr, the self-heating is not detected. Therefore, S1 to S3 are repeated.

[0089] By heating in S1 during the repetition of S1 to S3, Figure 6 The temperature of the sample Sp shown on the horizontal axis of rises to above the second temperature T2. As a result, the self-heating rate SHr becomes greater than the cooling rate Cr, and the self-heating is detected. Figure 5 The temperature of the sample Sp rises to above the third temperature T3 due to the self-heating in the pseudo-adiabatic state. At this time point, the self-heating rate SHr becomes lower than the cooling rate Cr again, so that the self-heating of the sample Sp is no longer detected. That is, the self-heating of the sample Sp ends, and at Figure 5 The determination in S5 shown is affirmative, so the process returns to S1.

[0090] Since the self-heating rate SHr is lower than the cooling rate Cr, S1 to S3 are repeated. Figure 6 The temperature of the sample Sp shown on the horizontal axis of rises to above the fourth temperature T4. As a result, the self-heating rate SHr becomes greater than the cooling rate Cr again, and self-heating is detected. Figure 5 S4 shown in the figure becomes a pseudo-adiabatic state. Figure 6 As shown in FIG. 1 , the self-heating rate SHr is greater than the cooling rate Cr, and the self-heating of the sample Sp is continuously detected and does not end, no matter how long it takes. Figure 5 The determination in S5 is negative, and the process proceeds to S6.

[0091] In the step S6, the temperature of the sample Sp detected in the last step S3 when self-heating occurs, that is, Figure 6 The fourth temperature T4 or a temperature slightly higher than the fourth temperature T4 is evaluated as a critical temperature Tnr at which the sample Sp will thermally run away even if cooled by the cooling device 60. The evaluation result, that is, the critical temperature Tnr, is outputted by displaying it on a display unit such as a monitor.

[0092] In addition, in Figure 6 In the sample Sp with the same situation as , when the cooling rate Cr is increased, the final intersection point of the cooling rate Cr and the self-heating rate SHr shifts to the right, that is, T4 shifts to the right, thereby increasing the critical temperature Tnr of the thermal runaway. Figure 6 In the sample Sp with the same situation, when the cooling rate Cr is set to be lowered, the final intersection point of the cooling rate Cr and the self-heating rate SHr shifts to the left, that is, T4 shifts to the left, thereby reducing the critical temperature Tnr of the thermal runaway.

[0093] Hereinafter, the structure and effects of this embodiment will be summarized.

[0094] like Figure 5 As shown, the control device 70 repeatedly performs a series of predetermined controls (S1 to S5). In the series of controls, in S3, when self-heating of the sample Sp is detected, the sample Sp is cooled by the cooling device 60 to try to end the self-heating, and at the same time, in S4, it is controlled to a pseudo-adiabatic state and follow-up observation is performed. The evaluation device 80 evaluates the temperature of the sample Sp whose self-heating has not ended during the repetition of the series of controls (S1 to S5) as the critical temperature Tnr at which the sample Sp will still thermally run away even if it is cooled by the cooling device 60.

[0095] Therefore, by Figure 1The configuration of the cooling device 60 and the cooling speed and other structures shown are simulated as structures related to actual cooling means, and the critical temperature Tnr at which the sample Sp will thermally run away even with the cooling means can be evaluated.

[0096] The evaluation results can be fed back into the design of the IPU. Specifically, for example, when the release valve of the battery cell is opened and the heat of vaporization of the electrolyte is used to lower the temperature of the battery cell, it can be known to what degree the temperature should be lowered.

[0097] Furthermore, since the sample Sp is cooled by the cooling device 60, the temperature rise of the sample Sp due to the self-heating of the sample Sp can be suppressed accordingly. Therefore, the load of the surrounding heating device 20 when the pseudo-adiabatic state is maintained can be reduced accordingly.

[0098] like Figure 1 As shown, the heating safety evaluation device 100 includes not only the cooling device 60 but also the heating device 50. Thus, the temperature distribution around the sample Sp can be simulated with higher accuracy to the actual temperature distribution.

[0099] like Figure 2 As shown in FIG. 1 , the cooling device 60 includes a cooling Peltier element Pc, which is an element having a heat absorbing surface and a heat generating surface. The sample Sp is cooled by the heat absorbing surface of the cooling Peltier element Pc. Figure 1 The heat balance within the system container 10 based on the cooling device 60 is shown to be zero.

[0100] Figure 1 The detection limit of the temperature rise rate of the first sensor 41 is 0.02°C / min. When the temperature is below the detection limit, it is considered that the self-heating has ended, so that the evaluation test can be completed with the highest accuracy.

[0101] like Figure 2 As shown, the cooling device 60 includes a cooling Peltier element Pc for cooling the sample Sp by means of a heat absorbing surface, and a cooling circuit Cc for supplying power to the cooling Peltier element Pc. The control device 70 controls the cooling device 60 by controlling the cooling circuit Cc. Therefore, the cooling speed Cr of the cooling device 60 can be quantitatively controlled.

[0102] like Figure 2 As shown, the heating device 50 includes a heating Peltier element Ph that heats the sample Sp through a heating surface, and a heating circuit Ch that supplies power to the heating Peltier element Ph. The control device 70 controls the heating device 50 by controlling the heating circuit Ch. Therefore, the heating speed of the heating device 50 can be quantitatively controlled.

[0103] like Figure 3 , Figure 4 As shown, a plurality of Peltier elements Ph and Pc are provided for the sample Sp. By controlling such a plurality of Peltier elements Ph and Pc, the temperature and temperature distribution of the sample Sp can be controlled with high precision. Therefore, the actual state can be simulated with higher precision.

[0104] like Figure 3 , Figure 4 As shown, a predetermined portion of the sample Sp is heated by the heat generating surface of the heating Peltier element Ph. Other portions of the sample Sp are cooled by the heat absorbing surface of the cooling Peltier element Pc. In this way, the sample Sp can be heated and cooled by using a plurality of Peltier elements Ph and Pc.

[0105] like Figure 3 As shown in FIG. 1 , if the sample container 30 is made into a hexahedron, it is easy to perform a test that simulates, for example, a hexahedron-shaped IPU housing. Figure 4 As shown, if the sample container 30 is made cylindrical, it is easy to perform a test imitating a cylindrical housing of an IPU, for example.

[0106] [Other embodiments]

[0107] The above-described embodiment can be modified as follows, for example. Figure 2 The cooling device 60 shown in the figure may also cool the sample Sp by means other than the Peltier element, such as an air cooling device or a water cooling device. The heating device 50 may also heat the sample Sp by means other than the Peltier element, such as various heating elements. Figure 1 The heating device 50 shown may be omitted if the temperature distribution of the sample Sp can be simulated with sufficiently high accuracy to the actual temperature distribution.

[0108] Reference numerals

[0109] 10 System Containers

[0110] 20Ambient heating device

[0111] 30 sample containers

[0112] 41 First Sensor

[0113] 42 Second sensor

[0114] 50 Heating device

[0115] 60 Cooling device

[0116] 70 Control Device

[0117] 80 Evaluation device

[0118] 100 Heating safety evaluation device

[0119] The surface temperature of the sample container

[0120] Tb The ambient temperature of the sample container

[0121] Ch heating circuit

[0122] Cc cooling circuit

[0123] Peltier element for Ph heating (Peltier element)

[0124] Peltier element for PC cooling (Peltier element)

[0125] Sp Sample

[0126] Self-heating rate of SHr sample

[0127] Cooling rate of Cr sample

[0128] Critical temperature of thermal runaway of Tnr samples

Claims

1. A heating safety evaluation device, comprising: a sensor to detect self-heating of the sample; and, A peripheral heating device configured to heat the periphery of the sample; Furthermore, the heating safety evaluation device comprises: a cooling device configured to cool the sample; and A control device that repeatedly performs a prescribed series of controls; The aforementioned series of controls is to heat the aforementioned sample, and then, when the aforementioned sensor detects the aforementioned self-heating, the aforementioned sample is cooled by the aforementioned cooling device to try to end the aforementioned self-heating, and at the same time, the aforementioned surrounding heating device is used to heat the sample to form a pseudo-adiabatic state control, The pseudo-adiabatic state is a state in which the heat balance between the sample cooled by the cooling device and its surroundings is zero. The heating safety evaluation device evaluates the temperature of the sample when the self-heating has not yet ended during the repetition of the series of controls as a critical temperature at which the sample will still experience thermal runaway even if cooled by the cooling device.

2. The heating safety evaluation device according to claim 1, comprising a heating device configured to heat the sample. The aforementioned series of controls is to heat the aforementioned sample, and then, when the aforementioned sensor detects the aforementioned self-heating, the aforementioned cooling device cools the aforementioned sample and the aforementioned heating device heats the aforementioned sample, and at the same time, the aforementioned surrounding heating device heats the aforementioned sample to form a pseudo-adiabatic state control, The pseudo-adiabatic state is a state in which the heat balance between the sample cooled by the cooling device and heated by the heating device and its surroundings is zero.

3. The heating safety evaluation device according to claim 1 or 2, wherein: The cooling device includes a component having a heat absorbing surface and a heat generating surface, and cools the sample via the heat absorbing surface.

4. The heating safety evaluation device according to claim 1 or 2, wherein: The control device determines that the self-heating is terminated when the temperature rise rate of the sample is 0.02° C. / min or less.

5. The heating safety evaluation device according to claim 3, wherein: The cooling device includes a cooling Peltier element for cooling the sample via the heat absorbing surface, and a cooling circuit for supplying power to the cooling Peltier element. The control device controls the cooling device by controlling the cooling circuit.

6. The heating safety evaluation device according to claim 2, wherein: The heating device includes a heating Peltier element for heating the sample by heating the surface, and a heating circuit for supplying power to the heating Peltier element. The control device controls the heating device by controlling the heating circuit.

7. The heating safety evaluation device according to claim 1 or 2, wherein: For the aforementioned sample, a plurality of Peltier elements are provided.

8. The heating safety evaluation device according to claim 2, wherein: The heating device includes a heating Peltier element for heating the sample by means of a heating surface, and a heating circuit for supplying power to the heating Peltier element. The cooling device includes a cooling Peltier element for cooling the sample by means of a heat absorbing surface, and a cooling circuit for supplying power to the cooling Peltier element. The heating surface of the heating Peltier element is used to heat a predetermined portion of the sample. The other parts of the sample are cooled by the heat absorbing surface of the cooling Peltier element.

9. The heating safety evaluation device according to claim 1 or 2, further comprising a sample container for accommodating the sample. The sample container is in a hexahedral shape.

10. The heating safety evaluation device according to claim 1 or 2, further comprising a sample container for accommodating the sample. The sample container is cylindrical.

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