Thermoelectric generation device

Abstract

To provide a thermoelectric generation device capable of discharging rapidly.SOLUTION: A thermoelectric generation device 1 includes: a thermoelectric cell 10 having an electrode pair 11 in which a first electrode 11A and a second electrode 11B face each other through an electrolyte 11C and which generates an electromotive force between the first electrode 11A and the second electrode 11B according to temperature changes of the first electrode 11A and the second electrode 11B; a detection unit 30 for detecting the voltage value of the output voltage of the thermoelectric cell 10; a voltage range information acquisition unit 40 for acquiring input voltage range information indicating a specific value that specifies the input voltage range in which a load L connected to the thermoelectric cell 10 can operate in the absolute value; and a short-circuit unit 50 which short-circuits a first terminal 10A and a second terminal 10B of the thermoelectric cell 10 when the absolute value of the voltage value falls below the minimum value of the specific value indicated by the input voltage range information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a thermoelectric generator. [Background technology]

[0002] In recent years, clean energy sources that emit less greenhouse gases such as carbon dioxide and other harmful substances such as nitrogen oxides have been attracting attention, and examples of clean energy include thermoelectric power generation, which converts thermal energy into electrical energy. Technologies related to such thermoelectric power generation include those described in Patent Document 1, the source of which is shown below.

[0003] Patent Document 1 describes a thermoelectric generator. This thermoelectric generator has a first electrode containing a material that generates one of a positive electromotive force and a negative electromotive force as the temperature increases, and a second electrode containing a material that generates the other of a positive electromotive force and a negative electromotive force as the temperature increases. The thermoelectric generator generates electricity by creating a temperature difference between the first electrode and the second electrode. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-73596 A Summary of the Invention [Problem to be solved by the invention]

[0005] The tertiary battery using the thermoelectric generating element described in Patent Document 1 is used in a charge / discharge cycle consisting of charging by heating, discharging by connecting an apparatus, charging by cooling, and discharging by connecting an apparatus. When discharging by connecting an apparatus, if the output voltage of the tertiary battery becomes lower than the operating voltage of the apparatus, discharging must be performed even though the apparatus is not operating. This lengthens the time required for discharging, limiting the number of times the apparatus can be operated per hour.

[0006] Therefore, there is a demand for a thermoelectric generating device that is capable of quickly discharging. [Means for solving the problem]

[0007] The characteristic configuration of the thermoelectric power generation device of the present invention is that it comprises a thermal battery having an electrode pair in which a first electrode and a second electrode face each other via an electrolyte and an electromotive force is generated between the first electrode and the second electrode in response to a temperature change of the first electrode and the second electrode, a detection unit that detects a voltage value of an output voltage of the thermal battery, a voltage range information acquisition unit that acquires input voltage range information indicating, as an absolute value, a specified value that specifies an input voltage range in which a load connected to the thermal battery can operate, and a short-circuiting unit that short-circuits a first terminal and a second terminal of the thermal battery when the absolute value of the voltage value falls below the minimum value of the specified value indicated in the input voltage range information.

[0008] With this characteristic configuration, the first and second terminals of the thermal battery are short-circuited to each other after the operation of the load connected to the thermal battery is completed, thereby shortening the discharge time of the thermal battery. Therefore, it is possible to quickly discharge the thermal battery, and therefore the number of operations of the load per unit time (in a given period of time) can be increased. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a configuration of a thermoelectric power generation device. [Diagram 2] FIG. 2 is an explanatory diagram of the process of a thermoelectric power generation device. [Diagram 3] 1 is an example of a circuit of a short circuit. [Figure 4] 4 is a flowchart showing a process in a thermoelectric power generation device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The thermoelectric power generation device according to the present invention can increase the number of times a load operates in a given time. Hereinafter, a thermoelectric power generation device 1 according to the present embodiment will be described. However, the thermoelectric power generation device 1 is not limited to the following embodiment, and various modifications are possible without departing from the gist of the invention.

[0011] Fig. 1 is a block diagram showing a schematic configuration of a thermoelectric power generation device 1. As shown in Fig. 1, the thermoelectric power generation device 1 includes a thermal battery 10, a detection unit 30, a voltage range information acquisition unit 40, a short-circuit unit 50, and a switching unit 60. Each functional unit is constructed of hardware or software, or both, with a CPU as a core member, in order to perform processing related to an increase in the number of operations of the load L.

[0012] The thermal battery 10 has an electrode pair 11 and a flow path 15. In this embodiment, the thermal battery 10 has a plurality of electrode pairs 11 (three in the example of FIG. 1), and the plurality of electrode pairs 11 are stacked to form an electrode pair group 16. The electrode pair group 16 and the flow path 15 are housed in a case 10C. In the following, when the three electrode pairs 11 are to be distinguished, they will be described as electrode pair 12, electrode pair 13, and electrode pair 14, and when they are not to be distinguished, they will be described as electrode pair 11.

[0013] The electrode pair 11 includes a first electrode 11A, a second electrode 11B, and an electrolyte 11C. The first electrode 11A and the second electrode 11B are provided opposite each other via the electrolyte 11C. That is, the electrode pair 11 is provided in the order of the first electrode 11A, the electrolyte 11C, and the second electrode 11B.

[0014] The first electrode 11A and the second electrode 11B have different temperature coefficients of redox potential. At least one of the first electrode 11A and the second electrode 11B contains a material that undergoes a structural phase transition and changes its redox potential in response to a temperature change (for example, a material that undergoes a structural phase transition and changes its redox potential significantly from Co-PBA (cobalt Prussian Blue complex)). The thermal battery 10 is configured to generate an electromotive force by raising or lowering the temperatures of the first electrode 11A and the second electrode 11B to generate a difference in redox potential between the first electrode 11A and the second electrode 11B.

[0015] In this embodiment, an electrolytic solution is used as the electrolyte 11C. Of course, the electrolyte 11C may be solid. The electrolytic solution of the electrolyte 11C can be appropriately selected from those used in conventional batteries. In this embodiment, as described above, the first electrode 11A and the second electrode 11B contain a material whose volume changes due to a structural phase transition, so that the first electrode 11A and the second electrode 11B can be immersed in the electrolytic solution to maintain contact between the first electrode 11A and the second electrode 11B and the electrolyte 11C even if the volume of the first electrode 11A and the second electrode 11B changes. In addition, when the electrolyte 11C is an electrolytic solution, a non-flammable aqueous electrolytic solution with a small potential window can be used because the potential is low, which can further improve safety.

[0016] Such an electrolyte can be, for example, an alkali metal salt such as sodium perchlorate (NaClO4), sodium chloride (NaCl), or lithium perchlorate (LiClO4) dissolved in a solvent such as water, propylene carbonate (PC), ethylene carbonate (EC), or diethyl carbonate (DEC).

[0017] The flow path 15 is capable of switching between a high-temperature fluid having a temperature higher than a predetermined temperature and a low-temperature fluid having a temperature lower than a predetermined temperature. In this embodiment, the high-temperature fluid is, for example, a fluid having a temperature of 50-55°C or higher, and the low-temperature fluid is, for example, a fluid having a temperature of 20-0°C or lower. Therefore, the flow path 15 is configured to be capable of switching between a fluid having a temperature of 50-55°C or higher and a fluid having a temperature of 20-0°C or lower.

[0018] In this embodiment, the flow paths 15 are provided on both sides of each of the electrode pairs 11 in the electrode pair group 16 along the stacking direction. That is, each of the electrode pairs 12, 13, and 14 is sandwiched between the flow paths 15 along the stacking direction of the electrode pairs 11. In this way, when a high-temperature fluid is circulated through the above-mentioned flow paths 15, the first electrode 11A and the second electrode 11B can be heated, and when a low-temperature fluid is circulated through the flow paths 15, the first electrode 11A and the second electrode 11B can be cooled.

[0019] In this embodiment, the flow path 15 between two adjacent electrode pairs 11 is configured as a single common flow path. That is, as shown in Fig. 1, the flow path 15 between the electrode pair 12 and the electrode pair 13 is provided as a common flow path 17, and the flow path 15 between the electrode pair 13 and the electrode pair 14 is provided as a common flow path 18. In order to distinguish between these common flow paths 17 and 18, the flow path 15 on the outer side of the first electrode 11A in the electrode pair 12 will be referred to as an outer flow path 19, and the flow path 15 on the outer side of the second electrode 11B in the electrode pair 14 will be referred to as an outer flow path 20.

[0020] The flow paths 15 are provided with control valves 70 capable of changing the amount of fluid flowing through each of the flow paths 15. Specifically, a control valve 71 is provided in the common flow path 17, and a control valve 72 is provided in the common flow path 18. In addition, a control valve 73 is provided in the outer flow path 19, and a control valve 74 is provided in the outer flow path 20.

[0021] The flow paths 15 are provided by branching off from an inflow side flow path 81 and joining together at an outflow side flow path 82. A fluid is supplied from a pump P to the inflow side flow path 81.

[0022] The thermoelectric power generation device 1 also has a first communication passage 90, a second communication passage 91, a third communication passage 92, a fourth communication passage 93, a fifth communication passage 94, a sixth communication passage 95, a first valve device 96, a second valve device 97, a high-temperature fluid supply section 98, a low-temperature fluid supply section 99, and a pump P.

[0023] The high-temperature fluid supply unit 98 corresponds to a supply source that supplies the above-mentioned high-temperature fluid. When the thermoelectric power generation device 1 is mounted on a vehicle, for example, an engine or a battery can be used as a heating source for the high-temperature fluid supply unit 98, and the coolant discharged from the engine or the battery can be used as the high-temperature fluid.

[0024] The low-temperature fluid supply unit 99 corresponds to a supply source that supplies the above-mentioned low-temperature fluid. When the thermoelectric power generation device 1 is mounted on a vehicle, for example, a chiller used in a heat exchange system mounted on the vehicle can be used as a cooling source for the low-temperature fluid supply unit 99, and a cooling liquid cooled by the chiller can be used as the low-temperature fluid.

[0025] The first communication passage 90 is provided between the high-temperature fluid supply unit 98 and the first valve device 96. This allows the first communication passage 90 to allow fluid (high-temperature fluid) to flow between the high-temperature fluid supply unit 98 and the first valve device 96.

[0026] The second communication passage 91 is provided between the second valve device 97 and the high-temperature fluid supply unit 98. This allows the second communication passage 91 to allow fluid (high-temperature fluid that has passed through the thermal battery 10) to flow between the second valve device 97 and the high-temperature fluid supply unit 98.

[0027] The third communication passage 92 is provided between the low-temperature fluid supply unit 99 and the first valve device 96. This allows the third communication passage 92 to allow fluid (low-temperature fluid) to flow between the low-temperature fluid supply unit 99 and the first valve device 96.

[0028] The fourth communication passage 93 is provided between the second valve device 97 and the low-temperature fluid supply unit 99. This allows the fourth communication passage 93 to allow fluid (low-temperature fluid that has passed through the thermal battery 10) to flow between the second valve device 97 and the low-temperature fluid supply unit 99.

[0029] The fifth communication passage 94 is provided between the first valve device 96 and the thermal battery 10. This allows the fifth communication passage 94 to allow fluid (high temperature fluid and low temperature fluid) to flow between the first valve device 96 and the thermal battery 10.

[0030] The sixth communication passage 95 is provided between the thermal battery 10 and the second valve device 97. This allows the sixth communication passage 95 to allow fluid (high-temperature fluid and low-temperature fluid that have passed through the thermal battery 10) to flow between the thermal battery 10 and the second valve device 97.

[0031] The first valve device 96 is a three-way valve having three communication holes. The three communication holes are provided so as to communicate with the first communication passage 90, the third communication passage 92, and the fifth communication passage 94, respectively. The first valve device 96 is configured to be switchable between a first communication state and a second communication state. In the first communication state, the first communication passage 90 and the fifth communication passage 94 are in communication with each other, and in the second communication state, the third communication passage 92 and the fifth communication passage 94 are in communication with each other.

[0032] The second valve device 97 is a three-way valve having three communication holes. The three communication holes are provided to communicate with the second communication passage 91, the fourth communication passage 93, and the sixth communication passage 95, respectively. The second valve device 97 is configured to be switchable between a third communication state and a fourth communication state. In the third communication state, the sixth communication passage 95 and the second communication passage 91 are in communication with each other, and in the fourth communication state, the sixth communication passage 95 and the fourth communication passage 93 are in communication with each other.

[0033] The pump P is provided in the fifth communication passage 94. In this embodiment, the pump P is provided in the fifth communication passage 94 so as to cause fluid to flow from the first valve device 96 side to the thermal battery 10 side.

[0034] The switching unit 60 switches between the high-temperature fluid and the low-temperature fluid when one of the high-temperature fluid and the low-temperature fluid is flowing through the flow path 15. When the high-temperature fluid is flowing through the flow path 15, the switching unit 60 sets the first valve device 96 to a first communication state in which the first communication passage 90 and the fifth communication passage 94 are in a communication state, and sets the second valve device 97 to a third communication state in which the second communication passage 91 and the sixth communication passage 95 are in a communication state. When the low-temperature fluid is flowing through the flow path 15, the switching unit 60 sets the first valve device 96 to a second communication state in which the third communication passage 92 and the fifth communication passage 94 are in a communication state, and sets the second valve device 97 to a fourth communication state in which the fourth communication passage 93 and the sixth communication passage 95 are in a communication state.

[0035] Therefore, when a low-temperature fluid is circulated through the flow path 15 in a state where a high-temperature fluid is circulating through the flow path 15, the switching unit 60 switches the first valve device 96 from the first communication state to the second communication state and switches the second valve device 97 from the third communication state to the fourth communication state. Moreover, when a high-temperature fluid is circulated through the flow path 15 in a state where a low-temperature fluid is circulating through the flow path 15, the switching unit 60 switches the first valve device 96 from the second communication state to the first communication state and switches the second valve device 97 from the fourth communication state to the third communication state.

[0036] In addition, the switching unit 60 controls the operation of the pump P. This makes it possible to adjust the amount of high-temperature fluid throughout the entire flow path 15 when a high-temperature fluid is circulated through the flow path 15, and also makes it possible to adjust the amount of low-temperature fluid throughout the entire flow path 15 when a low-temperature fluid is circulated.

[0037] Furthermore, the switching unit 60 can also adjust the amount of high-temperature fluid and low-temperature fluid flowing through each of the multiple flow paths 15 for each flow path 15. When increasing the amount of fluid, the switching unit 60 increases the opening of the control valve 70 provided in the outer flow path 15 along the stacking direction of the target electrode pair 11 so as to increase the amount of fluid flowing through that outer flow path 15. This makes it possible to increase the amount of fluid individually.

[0038] Further, when the switching unit 60 reduces the amount of the high-temperature fluid or the low-temperature fluid flowing through each of the plurality of flow paths 15, the opening degree of the control valve 70 provided in the outer flow path 15 along the stacking direction of the target electrode pair 11 is reduced so that the amount of the fluid flowing through the outer flow path 15 is reduced. Thereby, it becomes possible to reduce the amount of the fluid individually.

[0039] The detection unit 30 detects the voltage value of the output voltage of the thermoelectric battery 10. The output voltage of the thermoelectric battery 10 is the voltage output from the first terminal 10A and the second terminal 10B of the thermoelectric battery 10. Therefore, the detection unit 30 detects the potential difference between the first terminal 10A and the second terminal 10B. The potential difference detected by the detection unit 30 is transmitted to a short-circuit unit 50 described later.

[0040] The voltage range information acquisition unit 40 acquires input voltage range information indicating, in absolute value, a specified value that defines the operable input voltage range of the load L connected to the thermoelectric battery 10. The load L connected to the thermoelectric battery 10 is a device that is connected across the first terminal 10A and the second terminal 10B described above and consumes the electric power supplied from the thermoelectric battery 10. Examples of such a load L include accessories mounted on a vehicle.

[0041] As described above, for such a load L, when power is supplied from the thermoelectric battery 10 and a voltage is applied along with the power supply, an input voltage range in which the load L can operate is defined in advance for each load L. Specifically, as shown in #1 of FIG. 2, when the load L operates with a positive voltage, for example, the input voltage range is defined as V1 to V2 [V] (where V1 < V2), and when the load L operates with a negative voltage, for example, the input voltage range is defined as -V2 to -V1 [V] (where -V2 < -V1) (see #2 of FIG. 2). Therefore, in this case, the input voltage range information indicating the specified value that defines the input voltage range in absolute value is represented by V1 [V] and V2 [V] (see #3 of FIG. 2).

[0042] When such an input voltage range is stored in the load L, the voltage range information acquisition unit 40 can be configured to acquire it from the load L via a network. Alternatively, the user may be configured to input the input voltage range of the load L to the voltage range information acquisition unit 40 in advance. The input voltage range information acquired by the voltage range information acquisition unit 40 is transmitted to a short-circuit unit 50 described later.

[0043] Note that the voltage values defining the positive voltage range and the voltage values defining the negative voltage range of the input voltage range may be different from each other. That is, when the input voltage range of the positive voltage is defined as V1 to V2 [V] (where V1 < V2), the input voltage range of the negative voltage may be defined as -V4 to -V3 [V] (where -V4 < -V3). In this case, the input voltage range information indicating the specified values for defining the input voltage range in absolute values is represented by V1 [V] and V2 [V], and V3 [V] and V4 [V].

[0044] When the absolute value of the voltage value is lower than the minimum value of the specified values indicated by the input voltage range information, the short-circuit unit 50 shorts the first terminal 10A and the second terminal 10B of the thermoelectric battery 10. The voltage value is the voltage value of the output voltage of the thermoelectric battery 10, and this voltage value is detected by the detection unit 30. Therefore, the absolute value of the voltage value corresponds to the absolute value of the voltage value detected by the detection unit 30. The minimum value of the specified values indicated by the input voltage range information refers to the minimum value among the input voltage range information indicating the specified values for defining the input voltage range in absolute values. In the present embodiment, as shown in #3 of FIG. 2, when the input voltage range information indicating the specified values for defining the input voltage range in absolute values is represented by V1 [V] and V2 [V] (where V1 < V2), the minimum value corresponds to V1 [V] (see #4 of FIG. 2).

[0045] In this case, assuming that the voltage value detected by the detection unit 30 is Vo, when the absolute value of Vo falls below V1 [V], the short-circuiting unit 50 short-circuits the first terminal 10A and the second terminal 10B of the thermal battery 10 (see #5 in FIG. 2). In this case, the short-circuiting unit 50 may short-circuit the first terminal 10A and the second terminal 10B of the thermal battery 10 via a resistor (not shown) having a predetermined resistance value or a switching element. This allows the short-circuiting to be performed while limiting the current, thereby preventing the occurrence of sparks or the like at the short-circuited location.

[0046] Here, as described above, the switching unit 60 switches between the high-temperature fluid and the low-temperature fluid when one of the high-temperature fluid and the low-temperature fluid is flowing through the flow path 15, but in this embodiment, the switching unit 60 is configured to switch after the short-circuiting unit 50 short-circuits the first terminal 10A and the second terminal 10B of the thermal battery 10. In general, when one of the high-temperature fluid and the low-temperature fluid is flowing through the flow path 15 and the other is switched to the high-temperature fluid and the low-temperature fluid, the thermal battery 10 needs to be discharged, but the short-circuiting by the short-circuiting unit 50 can shorten the time required for discharging.

[0047] In this embodiment, the short circuit unit 50 shorts based on the output of the thermal battery 10 when the absolute value of the voltage value falls below the minimum value. When the absolute value of the voltage value falls below the minimum value, it means that the load L cannot operate due to the output voltage of the thermal battery 10. Therefore, in this case, the output of the thermal battery 10 is used to short the first terminal 10A and the second terminal 10B of the thermal battery 10 by the short circuit unit 50.

[0048] Specifically, when the short circuit unit 50 uses a switch (a semiconductor switch such as a switching element, or a mechanical switch such as a relay) to short circuit the first terminal 10A and the second terminal 10B of the thermal battery 10, the switch is controlled to change from an open state to a closed state based on the power (residual power) remaining in the thermal battery 10 when the load L becomes unable to operate. Of course, a power different from the power output by the thermal battery 10 may be used.

[0049] Furthermore, as shown in #6 of FIG. 2, the short circuit unit 50 may be configured to maintain the short circuit state between the first terminal 10A and the second terminal 10B for a preset waiting time t. The preset waiting time t corresponds to the time for maintaining the short circuit state. Therefore, the short circuit unit 50 maintains the above-mentioned switch in a closed state for the preset waiting time t. This makes it easier for the temperature of the thermal battery 10 to transition to room temperature (ta) more quickly, as shown in #7 of FIG. 2. This not only reduces the residual power of the thermal battery 10 more quickly, but also prevents, for example, the charge of a capacitor provided between the thermal battery 10 and the load L, and the rise in potential due to the inductive reactance and capacitive reactance of the load L.

[0050] An example of a specific circuit of such a short-circuiting unit 50 is shown in Fig. 3. In the example of Fig. 3, the short-circuiting unit 50 is composed of a first short-circuiting unit 50A that short-circuits the first terminal 10A and the second terminal 10B when the potential of the first terminal 10A is a positive value (hereinafter referred to as "first state"), and a second short-circuiting unit 50B that short-circuits the first terminal 10A and the second terminal 10B when the potential of the first terminal 10A is a negative value (hereinafter referred to as "second state").

[0051] In this case, the first short-circuiting section 50A sets the resistance ratio of the resistors R1 and R2 so that, in the first state, when the potential difference between the first terminal 10A and the second terminal 10B is equal to or greater than the voltage value at which the load L can operate, the transistor (npn transistor) Q1 operates in the active region, and when the potential difference between the first terminal 10A and the second terminal 10B is smaller than the voltage value at which the load L can operate, the transistor Q1 does not operate. Furthermore, in the first state, when the potential difference between the first terminal 10A and the second terminal 10B is equal to or greater than the voltage value at which the load L can operate, the transistor (npn transistor) Q2 does not operate, and when the potential difference between the first terminal 10A and the second terminal 10B is smaller than the voltage value at which the load L can operate, the resistance ratio of the resistors R3 and R4 is set so that the transistor Q2 operates.

[0052] As a result, when the potential difference between the first terminal 10A and the second terminal 10B is equal to or greater than the voltage value at which the load L can operate, the transistor Q2 does not operate, and the first terminal 10A and the second terminal 10B are not short-circuited. On the other hand, when the potential difference between the first terminal 10A and the second terminal 10B becomes smaller than the voltage value at which the load L can operate, the transistor Q2 operates according to the output of the thermal battery 10, and the first terminal 10A and the second terminal 10B are short-circuited. In the first state, the transistors Q3 and Q4 of the second short-circuiting section 50B do not operate, regardless of the potential difference between the first terminal 10A and the second terminal 10B.

[0053] On the other hand, the second short-circuiting part 50B sets the resistance ratio of the resistors R5 and R6 so that in the second state, when the potential difference between the first terminal 10A and the second terminal 10B is equal to or greater than the voltage value at which the load L can operate, the transistor Q3 (pnp transistor) operates in the active region, and when the potential difference between the first terminal 10A and the second terminal 10B is smaller than the voltage value at which the load L can operate, the transistor Q3 does not operate. Furthermore, in the second state, when the potential difference between the first terminal 10A and the second terminal 10B is equal to or greater than the voltage value at which the load L can operate, the transistor Q3 does not operate, and when the potential difference between the first terminal 10A and the second terminal 10B is smaller than the voltage value at which the load L can operate, the transistor Q4 (pnp transistor) operates, the resistance ratio of the resistors R7 and R8 is set so that.

[0054] As a result, when the potential difference between the first terminal 10A and the second terminal 10B is equal to or greater than the voltage value at which the load L can operate, the transistor Q4 does not operate, and the first terminal 10A and the second terminal 10B are not short-circuited. On the other hand, when the potential difference between the first terminal 10A and the second terminal 10B becomes smaller than the voltage value at which the load L can operate, the transistor Q4 operates according to the output of the thermal battery 10, and the first terminal 10A and the second terminal 10B are short-circuited. In the second state, the transistors Q1 and Q2 of the first short-circuiting section 50A do not operate, regardless of the potential difference between the first terminal 10A and the second terminal 10B.

[0055] The above-mentioned waiting time t can be set by adjusting the base current and collector current of each of the transistors Q2 and Q4. When adjusting the collector current, for example, a resistor having a predetermined resistance value may be provided between the collector terminal of each of the transistors Q2 and Q4 and the first terminal 10A.

[0056] Next, the process of the thermoelectric power generation device 1 will be described with reference to the flowchart of Fig. 4. First, a high-temperature fluid is circulated through the flow path 15 of the thermal battery 10 to heat the thermal battery 10 (step #11). This heating is continued until the temperature of the thermal battery 10 is saturated (step #12: No).

[0057] When the temperature of the thermal battery 10 becomes saturated (step #12: Yes), the load L is electrically connected to the thermal battery 10 (step #13). This connection may be performed, for example, by providing a switch between the thermal battery 10 and the load L and closing the switch. This causes power to be supplied from the thermal battery 10 to the load L. The power supply continues until the output voltage (voltage value) of the thermal battery 10 becomes equal to or lower than the operating voltage of the load L (step #14: No).

[0058] When the output voltage (voltage value) of the thermal battery 10 becomes equal to or lower than the operating voltage of the load L (step #14: Yes), the short circuiting unit 50 shorts the first terminal 10A and the second terminal 10B (step #15). After the short circuit, the load L is opened (electrical connection is released) (step #16), and a low-temperature fluid is circulated through the flow path 15 of the thermal battery 10 to cool the thermal battery 10 (step #17). This cooling continues until the temperature of the thermal battery 10 is saturated (step #18: No).

[0059] When the temperature of the thermal battery 10 is saturated (step #18: Yes), the load L is electrically connected to the thermal battery 10 (step #19). This causes power to be supplied from the thermal battery 10 to the load L. The power supply continues until the absolute value of the output voltage (voltage value) of the thermal battery 10 becomes equal to or lower than the operating voltage of the load L (step #20: No).

[0060] When the absolute value of the output voltage (voltage value) of the thermal battery 10 becomes equal to or lower than the operating voltage of the load L (step #20: Yes), the short-circuiting unit 50 shorts the first terminal 10A and the second terminal 10B (step #21). After the short-circuiting, the load L is released (electrical connection is released) (step #22).

[0061] If the operation of the thermoelectric power generation device 1 is to be ended (step #23: Yes), the process ends. If the operation of the thermoelectric power generation device 1 is to be continued (step #23: No), the process returns to step #11 and continues. The thermoelectric power generation device 1 is operated according to this flowchart.

[0062] Other embodiments Next, other embodiments of the thermoelectric power generation device 1 will be described.

[0063] In the above embodiment, the thermoelectric power generation device 1 has been described as having three electrode pairs 11. However, the number of electrode pairs 11 included in the thermoelectric power generation device 1 may be two or less, or four or more.

[0064] In the above embodiment, the switching unit 60 has been described as switching to the other of the high-temperature fluid and the low-temperature fluid after the first terminal 10A and the second terminal 10B of the thermal battery 10 are short-circuited in a state in which one of the high-temperature fluid and the low-temperature fluid flows through the flow path 15. However, the switching unit 60 does not have to switch to the other of the high-temperature fluid and the low-temperature fluid after the first terminal 10A and the second terminal 10B of the thermal battery 10 are short-circuited in a state in which one of the high-temperature fluid and the low-temperature fluid flows through the flow path 15.

[0065] In the above embodiment, the short circuit unit 50 is described as short circuiting based on the output of the thermal battery 10 when the absolute value of the voltage value of the output voltage of the thermal battery 10 falls below the minimum value. However, the short circuit unit 50 can be configured to short circuit based on a power different from the output of the thermal battery 10 when the absolute value of the voltage value of the output voltage of the thermal battery 10 falls below the minimum value.

[0066] In the above embodiment, the short-circuiting unit 50 has been described as maintaining the short-circuited state between the first terminal 10A and the second terminal 10B for the preset waiting time t. However, the short-circuiting unit 50 may instantly end the short-circuited state between the first terminal 10A and the second terminal 10B.

[0067] In the above embodiment, the output voltage of the thermal battery 10 is alternately output as a positive voltage value and a negative voltage value in #6 of Fig. 2. However, it is also possible to configure the thermal battery 10 to output an output voltage of a positive voltage value again from when the output voltage of the positive voltage value falls below the voltage value V1 at which the load L can operate until when the output voltage of the negative voltage value falls below the voltage value -V1 at which the load L can operate, and to configure the thermal battery 10 to output an output voltage of a negative voltage value again from when the output voltage of the negative voltage value exceeds the voltage value -V1 at which the load L can operate until when the output voltage of the positive voltage value exceeds the voltage value V1 at which the load L can operate.

[0068] [Summary of the above embodiment] The above-described thermoelectric power generation device 1 will now be outlined.

[0069] (1) The thermoelectric power generation device 1 includes a thermal battery 10 having an electrode pair 11 in which a first electrode 11A and a second electrode 11B face each other via an electrolyte 11C, and an electromotive force is generated between the first electrode 11A and the second electrode 11B in response to a temperature change of the first electrode 11A and the second electrode 11B, a detection unit 30 that detects a voltage value of an output voltage of the thermal battery 10, a voltage range information acquisition unit 40 that acquires input voltage range information indicating, as an absolute value, a specified value that specifies an input voltage range in which a load L connected to the thermal battery 10 can operate, and a short-circuiting unit 50 that short-circuits the first terminal 10A and the second terminal 10B of the thermal battery 10 when the absolute value of the voltage value falls below the minimum value of the specified values ​​indicated in the input voltage range information.

[0070] According to this configuration, after the operation of the load L connected to the thermal battery 10 ends, the first terminal 10A and the second terminal 10B of the thermal battery 10 are short-circuited to each other, thereby shortening the discharge time of the thermal battery 10. Therefore, the thermal battery 10 can be quickly discharged, and the number of operations of the load L per unit time (in a given period of time) can be increased.

[0071] (2) The thermoelectric power generation device 1 described in (1) is preferably further provided with a switching unit 60 that switches between the high-temperature fluid and the low-temperature fluid when the thermal battery 10 has a flow path 15 that can switch between a high-temperature fluid having a temperature higher than a predetermined temperature and a low-temperature fluid having a temperature lower than a predetermined temperature, and that switches between the high-temperature fluid and the low-temperature fluid after the first terminal 10A and the second terminal 10B of the thermal battery 10 are short-circuited when one of the high-temperature fluid and the low-temperature fluid is flowing through the flow path 15.

[0072] According to this configuration, after the first terminal 10A and the second terminal 10B of the thermal battery 10 are short-circuited, a temperature change can be applied to the first electrode 11A and the second electrode 11B of the thermal battery 10, so that an electromotive force can be generated in the thermal battery 10. Therefore, it is possible to quickly resume the power supply of the thermal battery 10.

[0073] (3) In the thermoelectric power generation device 1 described in (1) or (2), it is preferable that the short-circuiting part 50 short-circuits based on the output of the thermal battery 10 when the absolute value of the voltage value falls below a minimum value.

[0074] According to this configuration, after the operation of the load L connected to the thermal battery 10 is finished, the first terminal 10A and the second terminal 10B of the thermal battery 10 are short-circuited to each other using the power remaining in the thermal battery 10 and to be discharged, so there is no need to prepare additional power for short-circuiting. This makes it possible to save energy in relation to the short circuit.

[0075] (4) In the thermoelectric power generation device 1 described in (1) or (2), it is preferable that the short-circuiting part 50 maintains the short-circuited state between the first terminal 10A and the second terminal 10B for a preset standby time t.

[0076] According to this configuration, even if capacitive reactance or inductive reactance is connected to the first terminal 10A or the second terminal 10B of the thermal battery 10, it is possible to reliably reduce the potential difference between the first terminal 10A and the second terminal 10B of the thermal battery 10. Therefore, it is possible to prevent a potential difference from occurring between the first terminal 10A and the second terminal 10B of the thermal battery 10 after the short circuit between the first terminal 10A and the second terminal 10B of the thermal battery 10 is released. [Industrial Applicability]

[0077] The technology disclosed herein can be used in thermoelectric power generation devices. [Explanation of symbols]

[0078] 10: thermal battery, 10A: first terminal, 10B: second terminal, 11: electrode pair, 11A: first electrode, 11B: second electrode, 11C: electrolyte, 15: flow path, 30: detection unit, 40: voltage range information acquisition unit, 50: short circuit unit, 60: switching unit, L: load, t: standby time

Claims

1. a thermal battery having an electrode pair in which a first electrode and a second electrode face each other via an electrolyte, and an electromotive force is generated between the first electrode and the second electrode in response to a temperature change of the first electrode and the second electrode; A detection unit that detects a voltage value of an output voltage of the thermal battery; a voltage range information acquisition unit that acquires input voltage range information indicating, as an absolute value, a specified value that specifies an input voltage range in which a load connected to the thermal battery can operate; a short-circuiting unit that short-circuits a first terminal and a second terminal of the thermal battery when an absolute value of the voltage value falls below a minimum value of the specified values ​​indicated by the input voltage range information; A thermoelectric power generation device comprising:

2. the thermal battery has a flow path capable of switching between a high-temperature fluid having a temperature higher than a predetermined temperature and a low-temperature fluid having a temperature lower than the predetermined temperature; 2. The thermoelectric power generation device according to claim 1, further comprising a switching unit that switches between the other of the high-temperature fluid and the low-temperature fluid after the first terminal and the second terminal of the thermal battery are short-circuited when one of the high-temperature fluid and the low-temperature fluid is flowing through the flow path.

3. The thermoelectric power generation device according to claim 1 , wherein the short-circuiting portion shorts based on an output of the thermal battery when the absolute value of the voltage value falls below the minimum value.

4. The thermoelectric power generation device according to claim 1 , wherein the short-circuiting portion maintains the short-circuited state between the first terminal and the second terminal for a preset standby time.

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