Cooling device and cooling system

Abstract

To provide a cooling device and cooling system which can prolong a battery life.SOLUTION: A cooling device is mounted in an electric flight body and cools a battery of the electric flight body. The cooling device includes one or more kinds of heat storage materials which absorb heat from the battery. The storage materials have a latent heat storage material 1711A to which a phase transition temperature is set so as to absorb heat generation of the battery accompanying take-off and / or a latent heat storage material 1711B to which a phase transition temperature is set so as to absorb heat generation of the battery accompanying landing, of heat generation of the battery accompanying take-off and heat generation of the battery accompanying landing as a latent heat storage material 1711.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The disclosure in this specification relates to a cooling device and a cooling system that are installed in an electric flying vehicle and cool a battery. [Background technology]

[0002] Patent Document 1 discloses a cooling system for cooling a battery pack installed in an electric aircraft. The contents of the prior art document are incorporated by reference as explanations of technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-530619 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, heat generation from the battery is absorbed by circulating a working fluid such as water. By continuously circulating the working fluid to an on-board heat sink during flight, heat generation from the battery pack is absorbed during flight. In addition, the battery pack is connected to an external cooling device on the ground and the working fluid is circulated to absorb heat generation. However, since an electric flying object has a unique battery load profile associated with the operations of takeoff, cruising, and landing, the cooling system disclosed in Patent Document 1 may shorten the battery life. In the above-mentioned viewpoints and other viewpoints not mentioned, further improvements are required for cooling devices and cooling systems that cool batteries.

[0005] One disclosed object is to provide a cooling device or system that can extend battery life. [Means for solving the problem]

[0006] One disclosed cooling device is: A cooling device mounted on an electric flying object (10) for cooling a battery (14) of the electric flying object, comprising: one or more types of heat storage material (171) that absorbs heat from the battery; The heat storage material includes, as a latent heat storage material (1711), a first latent heat storage material (1711A) whose phase transition temperature is set to absorb the heat generated by the battery during takeoff and the heat generated by the battery during landing, and / or a second latent heat storage material (1711B) whose phase transition temperature is set to absorb the heat generated by the battery during landing.

[0007] When the electric flying object takes off and lands, a high output load is applied to the battery. According to the disclosed cooling device, the phase transition temperature of the latent heat storage material is set with a focus on takeoff and landing, when heat generation in the battery increases rapidly. The phase transition temperature of the first latent heat storage material is set so as to absorb heat generation in the battery accompanying takeoff. The phase transition temperature of the second latent heat storage material is set so as to absorb heat generation in the battery accompanying landing. The cooling device includes the first latent heat storage material and / or the second latent heat storage material as the latent heat storage material that utilizes latent heat. This makes it possible to suppress deterioration of the battery and thereby extend the battery life.

[0008] Another disclosed cooling system is an on-board cooling device (17) mounted on the electric flying object (10) and configured to cool a battery (14) of the electric flying object using one or more types of thermal storage materials (171); an external cooling device (40) for cooling the battery on the ground; Equipped with The heat storage material includes, as a latent heat storage material (1711), a first latent heat storage material (1711A) whose phase transition temperature is set so as to absorb the heat generated by the battery during takeoff, and / or a second latent heat storage material (1711B) whose phase transition temperature is set so as to absorb the heat generated by the battery during landing, out of the heat generated by the battery during takeoff and the heat generated by the battery during landing, The external cooling device cools the heat storage material and the battery by causing a flowable medium to flow.

[0009] When the electric aircraft takes off and lands, a high output load is applied to the battery. According to the disclosed cooling system, the phase transition temperature of the latent heat storage material is set with a focus on takeoff and landing, when heat generation in the battery increases rapidly. The phase transition temperature of the first latent heat storage material is set so as to absorb heat generation in the battery accompanying takeoff. The phase transition temperature of the second latent heat storage material is set so as to absorb heat generation in the battery accompanying landing. The on-board cooling device includes the first latent heat storage material and / or the second latent heat storage material as the latent heat storage material that utilizes latent heat. This makes it possible to suppress deterioration of the battery and thereby extend the battery life.

[0010] The external cooling system circulates a fluid medium on the ground to cool the heat storage material and the battery, thereby enabling the aircraft to be adjusted to a state ready for the next flight in a short period of time.

[0011] The various aspects disclosed in this specification adopt different technical means to achieve their respective objectives. The claims and the parenthetical symbols described in this section are merely illustrative of the corresponding relationship with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer with reference to the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the configuration of an eVTOL and a ground station. [Diagram 2] FIG. 2 is a diagram showing a cooling device and a battery according to the first embodiment. [Diagram 3] FIG. 2 is a diagram showing an example of an arrangement of battery cells. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 2 illustrates a power profile. [Figure 6] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 7] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 8] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 9] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 10] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 11] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 12] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 13] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 14] FIG. 11 is a diagram showing the relationship between battery temperature and PCM1 during flight. [Figure 15] FIG. 13 is a diagram showing the relationship between battery temperature and PCM2 during flight. [Figure 16] FIG. 11 is a diagram showing the relationship between battery temperature and PCM1 and PCM2 during flight. [Figure 17] FIG. 11 is a diagram illustrating an example of a cooling device according to a second embodiment. [Figure 18] FIG. 2 is a diagram illustrating an example of a cooling device. [Figure 19] FIG. 4 is a diagram showing an example of the arrangement of a heat storage material. [Figure 20] FIG. 4 is a diagram showing an example of the arrangement of a heat storage material. [Figure 21] FIG. 4 is a diagram showing an example of the arrangement of a heat storage material. [Figure 22] FIG. 13 is a diagram showing an example equipped with a flow mechanism. [Figure 23] FIG. 4 is a diagram showing the relationship between battery temperature and heat absorption amount. [Figure 24] 13A and 13B are diagrams illustrating an example of a heat-conducting assistant member in a cooling device according to a third embodiment. [Diagram 25] FIG. 4 is a diagram showing an example of a heat conduction assistant member. [Figure 26] FIG. 13 is a diagram showing an example of an arrangement of a latent heat storage material in a cooling device according to a fourth embodiment. [Figure 27] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 28] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Figure 29] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Diagram 30] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Diagram 31] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Diagram 32] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Diagram 33] FIG. 2 is a diagram showing an example of the arrangement of a latent heat storage material. [Diagram 34] 13 is a diagram showing a cooling device and a cooling system according to a fifth embodiment. FIG. [Diagram 35] FIG. 2 is a diagram showing the relationship between devices constituting a cooling system and other devices. [Diagram 36] 11A and 11B are diagrams illustrating modified examples of the cooling device and the cooling system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, several embodiments will be described with reference to the drawings. In addition, by assigning the same reference numerals to corresponding components in each embodiment, duplicated explanations may be omitted. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. In addition to the combination of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0014] The cooling device and cooling system described below are applied to an electric flying object. Note that the description of A and / or B means at least one of A and B. In other words, it may include only A, only B, or both A and B.

[0015] (First embodiment) An electric flying body has a motor (rotating electric machine) as a drive source for movement. An electric flying body is sometimes called an electric airplane, an electric aircraft, etc. An electric flying body is capable of moving in the vertical direction and the horizontal direction. An electric flying body is capable of moving in a direction having a vertical component and a horizontal component, that is, in a diagonal direction. Examples of electric flying bodies include electric vertical take-off and landing aircraft (eVTOL), electric short take-off and landing aircraft (eSTOL), and drones. eVTOL is an abbreviation for electronic Vertical Take-Off and Landing aircraft. eSTOL is an abbreviation for electronic Short distance Take-Off and Landing aircraft.

[0016] The electric air vehicle may be either a manned or unmanned aircraft. In the case of a manned aircraft, the electric air vehicle is operated by a pilot as a pilot. In the case of an unmanned aircraft, the electric air vehicle may be operated by a remote control by a pilot, or may be automatically controlled by a control system. As an example, the electric air vehicle of this embodiment is an eVTOL.

[0017] <evtol> Fig. 1 shows an eVTOL and a ground station. As shown in Fig. 1, an eVTOL 10 includes an airframe 11, a fixed wing 12, a rotor 13, a battery 14, an EPU 15, a BMS 16, and a cooling device 17.

[0018] The aircraft body 11 is the fuselage of the aircraft. The aircraft body 11 has a shape that extends in the front-rear direction. The aircraft body 11 has a passenger compartment for passengers to ride in and / or a luggage compartment for carrying luggage.

[0019] The fixed wing 12 is a wing portion of the aircraft, and is connected to the aircraft body 11. The fixed wing 12 provides gliding lift. The gliding lift is the lift generated by the fixed wing 12. The fixed wing 12 may have a main wing 121 and a tail 122. The main wing 121 extends left and right from near the center in the fore-and-aft direction of the aircraft body 11. The tail 122 extends left and right from the rear of the aircraft body 11. The shape of the fixed wing 12 is not particularly limited. For example, a swept back wing, a delta wing, a straight wing, etc. can be adopted.

[0020] A plurality of rotors 13 are provided on the aircraft body. At least some of the plurality of rotors 13 may be provided on the fixed wing 12. At least some of the plurality of rotors 13 may be provided on the aircraft body 11. The number of rotors 13 provided on the eVTOL 10 is not particularly limited. A plurality of rotors 13 may be provided on each of the aircraft body 11 and the main wing 121.

[0021] The rotor 13 may be referred to as a rotor, a propeller, a fan, or the like. The rotor 13 may have blades 131 and a shaft 132. The blades 131 are attached to the shaft 132. The blades 131 are vanes that rotate together with the shaft 132. A plurality of the blades 131 extend radially around the axis of the shaft 132. The shaft 132 is a rotation axis of the rotor 13, and is rotated by a motor of the EPU 15.

[0022] The rotor 13 generates a thrust force by rotation. The thrust force acts on the eVTOL 10 mainly as a rotational lift during takeoff and landing operations of the eVTOL 10. The rotor 13 mainly provides rotational lift during takeoff and landing operations. The rotational lift is a lift force generated by the rotation of the rotor 13. During takeoff and landing operations, the rotor 13 may provide only the rotational lift, or may provide a forward thrust force in addition to the rotational lift. The rotor 13 provides rotational lift during hovering of the eVTOL 10.

[0023] The propulsive force acts primarily as thrust on the eVTOL 10 during cruising operation of the eVTOL 10. The rotor 13 primarily provides thrust during cruising operation. During cruising operation, the rotor 13 may provide only thrust or may provide lift in addition to thrust.

[0024] The battery (BAT) 14 is a device for driving the rotor 13 to rotate. The battery 14 may be referred to as a battery pack. The battery 14 can store DC power and has a rechargeable battery cell. The battery cell is a secondary battery that generates an electromotive force by a chemical reaction. The battery cell is, for example, a lithium ion secondary battery, a nickel-metal hydride secondary battery, or the like. The battery cell may be a secondary battery with a liquid electrolyte, or a so-called all-solid-state battery with a solid electrolyte. The battery cell may have a configuration in which the battery reaction occurs when ions (electrolyte) that contribute to the battery reaction move between the positive and negative electrodes via the electrolytic solution and / or solid electrolyte. The eVTOL 10 may include a fuel cell, a generator, or the like in addition to the battery 14 as a power source that supplies power to the device. The battery 14 supplies power to the EPU 15.

[0025] The battery 14 of the eVTOL 10 is required to have high capacity as well as high output performance. For this reason, a battery cell that can obtain both high capacity and high output is desirable. From the viewpoint of output, a battery cell with low resistance over a wide SOC range is desirable. In particular, a battery cell with low resistance even in the low SOC range and capable of obtaining high output is desirable. SOC is an abbreviation for State Of Charge.

[0026] The positive electrode material of the battery cell can be, for example, LCO, NMC, NCA, LFP, or LMFP. LCO is a lithium cobalt oxide (LiCoO 2 ) NMC is lithium nickel cobalt manganese oxide (Li(NiMnCo)O 2 ) NCA is lithium nickel cobalt aluminate (Li(NiCoAl)O 2 ). LFP stands for lithium iron phosphate (LiFePO 4 LMFP is lithium manganese iron phosphate (LiFe x Mn y PO 4 In particular, a positive electrode made of LMFP or a positive electrode made of a blend of LMFP and NMC, which has low resistance in the low SOC region, is preferred.

[0027] The negative electrode material of the battery cell can be, for example, carbon-based such as hard carbon or soft carbon, silicon, lithium-based, or titanium-based such as LTO or NTO. LTO is a lithium titanate (Li 4 Ti 5 O 12 ) NTO is niobium titanium oxide (TiNb 2 O 7 In particular, carbon-based and titanium-based negative electrodes, which have low resistance in the low SOC region, are preferred.

[0028] The EPU 15 drives and rotates the rotor 13 that imparts a propulsive force to the eVTOL 10. The EPU 15 is a device for driving and rotating the rotor 13. EPU is an abbreviation for Electric Propulsion Unit. The EPU 15 corresponds to an electric propulsion device. The EPU 15 includes a motor. The EPU 15 includes an inverter and an ESC in addition to the motor. ESC is an abbreviation for Electronic Speed ​​Controller. As an example, the same number of EPUs 15 as the rotors 13 are provided. That is, the eVTOL 10 includes six EPUs 15. The EPUs 15 and the rotors 13 are connected one-to-one. Alternatively, a configuration may be adopted in which two or more rotors 13 are connected to one EPU 15 via a gear box.

[0029] The BMS 16 monitors the status of the unit batteries constituting the battery 14. BMS is an abbreviation for Battery Management System. The BMS 16 can monitor the voltage, current, temperature, internal resistance, SOC, SOH, and other safety-related statuses of the battery 14, such as internal pressure and gas leakage. SOH is an abbreviation for State Of Health. The BMS 16 may be provided integrally with the battery 14. A part of the BMS 16 may be provided integrally with the battery 14, and another part may be provided separately from the battery 14.

[0030] The cooling device (IC) 17 is a cooling device provided inside the aircraft. For this reason, the cooling device 17 is sometimes referred to as an on-board cooling device. The cooling device 17 cools the battery 14. The cooling device 17 cools the battery 14 using a heat storage material. Details of the cooling device 17 will be described later.

[0031] The eVTOL 10 further includes an ECU 20 and auxiliary equipment (not shown). ECU is an abbreviation for Electronic Control Unit. The eVTOL 10 may include a lift adjustment mechanism (not shown). The lift adjustment mechanism adjusts the gliding lift of the fixed wing 12. The lift adjustment mechanism increases or decreases the gliding lift generated by the fixed wing 12. The eVTOL 10 may include, for example, a tilt mechanism or a flap as the lift adjustment mechanism. The tilt mechanism is driven to adjust the tilt angle of the rotor 13. The flap is a movable wing piece and is provided on the fixed wing 12.

[0032] <Operation control device> The traffic management device is a device for formulating a traffic plan, monitoring the traffic status, collecting and managing information related to the traffic, supporting the traffic, etc. At least a part of the functions of the traffic management device may be arranged in an onboard computer of the eVTOL 10. At least a part of the functions of the traffic management device may be arranged in an external computer capable of wireless communication with the eVTOL 10. An example of an external computer is the server 31 of the ground station 30 shown in FIG. 1. The ground station 30 is capable of wireless communication with the eVTOL 10. The ground stations 30 are capable of wireless communication with each other.

[0033] As an example, in this embodiment, some of the functions of the traffic management device are arranged in the ECU 20 of the eVTOL 10, and some of the functions of the traffic management device are arranged in the server 31 of the ground station 30. The functions of the traffic management device are shared between the ECU 20 and the server 31.

[0034] As shown in FIG. 1, the ECU 20 includes a processor (PC) 201, a memory (MM) 202, a storage (ST) 203, and a communication circuit (CC) 204 for wireless communication. The processor 201 executes various processes by accessing the memory 202. The memory 202 is a rewritable volatile storage medium. The memory 202 is, for example, a RAM. RAM is an abbreviation for Random Access Memory. The storage 203 is a rewritable non-volatile storage medium. The storage 203 stores a program (PG) 203P to be executed by the processor 201. The program 203P configures a plurality of functional units by causing the processor 201 to execute a plurality of instructions. The ECU 20 may include a plurality of processors 201.

[0035] Like the ECU 20, the server 31 is configured to include a processor (PC) 311, a memory (MM) 312, a storage (ST) 313, a communication circuit (CC) 314, and the like. The processor 311 executes various processes by accessing the memory 312. The memory 312 is a rewritable volatile storage medium, such as a RAM. The storage 313 is a rewritable non-volatile storage medium. The storage 313 stores a program (PG) 313P to be executed by the processor 311. The program 313P configures a plurality of functional units by causing the processor 311 to execute a plurality of instructions. The server 31 may include a plurality of processors 311.

[0036] <Battery> FIG. 2 shows a cooling device according to a first embodiment. FIG. 2 shows the relationship between the cooling device and the battery. FIG. 3 shows an example of the arrangement of the battery cells. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. In the following, the height direction of each battery cell is referred to as the Z direction, the longitudinal direction of each battery cell as the Y direction, and the lateral direction of each battery cell as the X direction. The X direction, Y direction, and Z direction are mutually orthogonal. In FIG. 4, for convenience, the entire battery cell is metal-hatched.

[0037] As shown in Fig. 2, the battery 14 includes a battery module (MOD) 141. As shown in Fig. 3, the battery module 141 is a modularized battery cell (CELL) 142. The battery module 141 is a battery assembly having the multiple battery cells 142.

[0038] The multiple battery cells 142 have a common structure. There is no particular limitation on the number or arrangement of the multiple battery cells 142. The multiple battery cells 142 may be connected in series, or in parallel and series.

[0039] The battery cell 142 has a power generating element and a battery case that houses the power generating element. The battery case provides an outer shell of the battery cell 142. The battery case may be formed, for example, using a metal material or a laminate film. The shape of the battery cell 142, that is, the battery case, is not particularly limited. For example, it may be cylindrical or rectangular. It may be a laminate type. As shown in FIG. 4, the battery cell 142 has end faces 1421 and 1422 and a side face 1423. The end face 1421 is the face opposite to the end face 1422 in the Z direction. The side face 1423 is a face that connects the end face 1421 and the end face 1422. The end faces 1421 and 1422 are the faces of the surface excluding the side face 1423.

[0040] Each battery cell 142 has electrode terminals 142P and 142N. The electrode terminals 142P and 142N may be provided only on the end surface 1421. The electrode terminals 142P and 142N may be provided on each of the end surfaces 1421 and 1422. For example, the electrode terminals 142P and 142N may be provided on the end surface 1421, and the electrode terminals 142P and 142N may be provided on the end surface 1322. One of the electrode terminals 142P and 142N may be provided on one of the end surfaces 1421 and 1422, and the other of the electrode terminals 142P and 142N may be provided on the other of the end surfaces 1421 and 1422. The electrode terminals 142P and 142N protrude from the corresponding end surface. The electrode terminal 142P is electrically connected to the positive electrode of the battery cell 142. The electrode terminal 142P may be referred to as a positive electrode terminal, a P terminal, or the like. The electrode terminal 142N is electrically connected to the negative electrode of the battery cell 142. The electrode terminal 142N may be referred to as a negative electrode terminal, an N terminal, etc. The electrode terminal may be referred to as a battery cell terminal, a current collecting tab, etc.

[0041] As an example, the battery cell 142 of this embodiment has a rectangular shape, specifically a flat shape that is thin in the X direction. The multiple battery cells 142 are arranged side by side in the X direction. The electrode terminals 142P, 142N are provided on end faces 1421. The multiple battery cells 142 are arranged such that the electrode terminals 142P and the electrode terminals 142N are positioned alternately in the X direction. The battery cells 142 are also arranged such that the Z direction positions of the end faces 1421 are approximately equal to each other. In adjacent battery cells 142, the electrode terminals 142P and the electrode terminals 142N are electrically connected by a bus bar (not shown).

[0042] The battery module 141 may include a plurality of battery cells 142 arranged in the X direction. The arrangement of the battery cells 142 is not limited to the above arrangement. For example, in the case of cylindrical battery cells 142, they may be arranged in a staggered pattern when viewed from the Z direction. The electrode terminals 142P, 142N may be provided on the end surface 1421 and the end surface 1422, respectively.

[0043] <Cooling device> The cooling device 17 cools the battery 14. The cooling device 17 may be provided in its entirety integral with the battery 14, or a portion of the cooling device 17 may be provided integrally with the battery 14. The cooling device 17 may be disposed inside the battery 14. The cooling device 17 may be provided separately from the battery 14 and thermally connected to the battery 14. The cooling device 17 may be provided integrally with the BMS 16, or may be provided separately from the BMS 16 and connected to the BMS 16 so as to be able to communicate with the BMS 16.

[0044] As shown in FIG. 2, the cooling device 17 has at least one type of heat storage material 171. The heat storage material 171 is a member that can store heat, that is, a member that exhibits a heat storage effect. The heat storage material 171 cools a target member by absorbing heat from the target member. The heat storage material 171 cools the battery cell 142 by absorbing heat generated by the battery cell 142 during charging and discharging. The heat storage material 171 is sometimes referred to as a cold storage material.

[0045] The heat storage material 171 includes at least a latent heat storage material (PCM) 1711. PCM is an abbreviation of Phase change material. The latent heat storage material 1711 undergoes a phase change between a solid phase and a liquid phase, or between solid phases. When the latent heat storage material 1711 undergoes a phase change, a very large amount of energy (latent heat) flows in and out of the latent heat storage material 1711 compared to sensible heat such as water. By utilizing this energy flow, it is possible to suppress a temperature rise in the battery 14 and to maintain the battery temperature in a specific temperature range near the phase transition temperature. By using the latent heat storage material 1711, the size of the cooling device 17, that is, the cooling volume, can be reduced. In addition, electricity and maintenance for cooling are not required.

[0046] Examples of latent heat storage materials that undergo a phase change from solid to liquid include organic materials such as paraffin, fatty acids, fatty acid esters, and sugar alcohols, and inorganic hydrate materials such as sodium acetate, sodium sulfate, and sodium nitrate. For example, paraffin has a relatively large latent heat, is inexpensive, and the phase transition temperature can be easily adjusted according to the molecular weight. Paraffin has the characteristic of being less susceptible to problems such as supercooling and phase separation. Latent heat storage materials that utilize the latent heat that occurs during a phase change between solid and liquid are not limited to the above examples.

[0047] As a latent heat storage material, a material whose crystal structure changes in the solid phase can be used. An example of a material that changes phase while remaining in the solid phase is VO 2 Or, VO 2 Examples of latent heat storage materials include electronic phase transition heat storage materials that undergo metal-insulator transition, such as vanadium oxide doped with multiple elements, and materials that undergo martensitic transformation. Other examples include thermochromic materials, plastic crystals, magnetic phase transition materials, and paraelectric-ferroelectric transition materials. Because the phase transition occurs in the solid phase, there is no need to liquefy and the change in volume is small, making it easy to handle without restrictions such as containers. Latent heat storage materials that utilize the latent heat generated during phase changes between solid phases are not limited to the above examples.

[0048] The form of use of the latent heat storage material 1711 is not particularly limited. The latent heat storage material 1711 may be used in a state filled in a thermally conductive container such as a metal case or a metal pack. The latent heat storage material 1711 may be used in a state filled in a capsule. The size of the capsule may be several mm or less. For example, the capsule may be on the order of several μm to several thousand μm, or may be a nanocapsule on the order of several nm to several hundred nm. The latent heat storage material 1711 may be used in a state filled in a housing (not shown) of the battery 14 so as to be thermally connected to a part or all of the battery cells 142. The latent heat storage material 1711 may be used in a state combined with a matrix. The matrix is ​​called a support, a holder, a mother body, or the like. For example, the latent heat storage material 1711 may be held in the voids of a metal foam, a metal porous body, porous carbon, or the like. The latent heat storage material 1711 may be combined with a resin, a rubber, a gel, or the like. The latent heat storage material 1711 may be used in a state in which it is formed into a predetermined shape together with a binder or the like. The predetermined shape may be, for example, a sheet, a film, a plate, or a cylinder. The latent heat storage material 1711 may be used in a state in which it is dispersed in a fluid heat storage material.

[0049] When the latent heat storage material 1711 needs to maintain its structure by a phase change from a solid phase to a liquid phase, any of the above-mentioned forms of use may be used, such as filling a container, filling a capsule, or compounding with a matrix. This allows the material to be handled like a solid. Even if the latent heat storage material 1711 changes phase from a solid to a liquid, it can be held in a predetermined position. The latent heat storage material 1711 may be molded into a predetermined shape while being filled in a capsule, or may be compounded with resin, rubber, gel, or the like. It may be dispersed and mixed in a fluid heat storage material.

[0050] The heat storage material 171 may contain other heat storage materials in addition to the latent heat storage material 1711. For example, it may contain a fluid heat storage material, which will be described later. It may also contain a metal material, such as aluminum or copper.

[0051] The total heat storage amount of the heat storage material 171 for absorbing heat from the battery 14 may be set so that the battery temperature during flight is equal to or lower than the upper usage temperature limit, based on the heat storage amount at the start of flight, the output load during flight, and the heat dissipation characteristics of the battery 14 excluding the effect of the heat storage material 171. The amount of the latent heat storage material 1711 may be set so that the phase change of the latent heat storage material 1711 is completed by absorbing the heat generated by the battery 14 due to the output load during flight. The amount of the latent heat storage material 1711 may be set so that an incomplete portion of the phase change remains in the latent heat storage material 1711 due to absorbing the heat generated by the battery 14 due to the output load during flight. The above setting may be performed for each flight or for each route. It may be performed for each season. It may be performed for each aircraft or for each model.

[0052] The total heat storage amount of the heat storage material 171, for example, the amount of the heat storage material 171 loaded, may be set using a thermal analysis simulation model or the like. Various parameters required for the thermal analysis simulation may be extracted from prior experiments, flight history, or the like. For example, the heat storage amount at the start of flight may be estimated from the battery temperature and / or the temperature of the heat storage material 171 at the start of flight. The output load during flight may be estimated from the flight route and past flight history. The heat dissipation characteristics of the battery 14 may be obtained by prior experiments or the like.

[0053] The risk of overheating of the battery 14 during flight can be reduced by calculating the amount of heat stored at the start of flight, the output load during flight, and the heat dissipation characteristics of the battery under the worst assumed conditions. For example, if landing at the planned landing point becomes difficult, the total amount of stored heat may be set in consideration of the output load required for flying to an alternative landing point and / or the output load required for retrying landing. This makes it possible to suppress an abnormal overheating of the battery 14 and increase the safety of the battery 14 even if a problem occurs during flight. In addition, the output load during flight may be assumed for multiple flights in accordance with the operation plan.

[0054] The cooling device 17 may have a cooling mechanism other than the heat storage material 171 in addition to the heat storage material 171. The cooling device 17 may have a mechanism for exchanging heat generated by the battery 14 with the metal frame of the aircraft. For example, it may have a heat sink that exchanges heat by contacting with cold air introduced from outside. The cold air may be cold air introduced from outside the aircraft, or cold air from the aircraft air conditioner.

[0055] The cooling device 17 may have a monitoring function and a control function in addition to the cooling function. The cooling device 17 may monitor the temperature of the heat storage material 171. The cooling device 17 may monitor the temperature of the battery 14. When a fluid heat storage material described below is included, the cooling device 17 may control the operation of a pump that circulates the fluid heat storage material. The cooling device 17 may notify the traffic management device of a request to limit the output of the battery 14 based on the battery temperature and / or heat storage information of the heat storage material 171. The monitoring function and the control function of the cooling device 17 may be arranged in the ECU 20. The BMS 16 and / or the traffic management device may have the above-mentioned monitoring function and control function.

[0056] <Power Profile> FIG. 5 shows the power profile of the eVTOL10 from takeoff to landing. The power profile of electric flying objects other than the eVTOL is similar to that of the eVTOL10. The period P1 is referred to as takeoff operation, takeoff, takeoff period, etc. The period P2 is referred to as cruising operation, cruising, cruising period, etc. The period P3 is referred to as landing operation, landing, landing period, etc. The periods P1 and P3 are referred to as takeoff and landing operation, takeoff and landing, takeoff and landing period, etc. For convenience, the required power, i.e., the output, is constant throughout almost the entire range of each of the periods P1 and P3 in FIG. 1.

[0057] The eVTOL 10 ascends from the takeoff point to the cruise start point in period P1. The eVTOL 10 cruises at a predetermined altitude in period P2. The eVTOL 10 descends from the end point of period P2 to the landing point in period P3. The movement of the eVTOL 10 includes mainly horizontal components in period P2 and mainly vertical components in periods P1 and P3. In periods P1 and P3 during vertical movement, high output is required continuously for a predetermined period of time to drive the rotor 13.

[0058] Thus, a high output load is applied to the battery 14 during takeoff and landing. The heat generated by the battery 14 increases rapidly during takeoff and landing. For this reason, in a configuration in which the sensible heat of a working fluid such as water or air is used to cool the battery 14, the heat cannot be absorbed in time, and there is a risk that the battery 14 will overheat and the battery will stop outputting. In addition, a sudden increase in heat generation will accelerate the deterioration of the battery 14, and there is a risk that the battery life will be extremely shortened.

[0059] <Layout of latent heat storage material> The latent heat storage material 1711 is thermally connected to the battery cell 142. The latent heat storage material 1711 may be in direct contact with the surface forming the outer periphery of the battery cell 142, or indirect contact with the surface. For example, the latent heat storage material 1711 may be in contact with the battery cell 142 via a thermal conductive member such as TIM. TIM is an abbreviation for Thermal Interface Material. The latent heat storage material 1711 may be in contact with the end face 1421 or the end face 1422. It may be in contact with the side face 1423. The latent heat storage material 1711 may be in contact with the side faces 1423 of different battery cells 142, that is, with a plurality of side faces 1423. The latent heat storage material 1711 may be in contact with only one side face 1423.

[0060] As an example, the latent heat storage material 1711 in this embodiment is in contact with the side surface 1423 of the battery cell 142. The latent heat storage material 1711 is in contact with the side surface 1423 in the longitudinal direction among the side surfaces 1423. The latent heat storage material 1711 is arranged alternately with the battery cells 142 in the X direction as shown in FIG. 3. The latent heat storage material 1711 is arranged between adjacent battery cells 142 as shown in FIG. 4, and is in contact with each of the side surfaces 1423 facing each other. The latent heat storage material 1711 is arranged on the side surface 1423 of the battery cell 142. The thickness of the latent heat storage material 1711 is approximately uniform within the plane.

[0061] Each of Figs. 6 to 13 is a diagram showing an example of the arrangement of the latent heat storage material. Figs. 6 to 13 correspond to Fig. 4. The heat storage material 171 includes a latent heat storage material (PCM1) 1711A and / or a latent heat storage material (PCM2) 1711B as the latent heat storage material 1711. The phase transition temperature of the latent heat storage material 1711A is set so as to absorb the heat generated by the battery 14 during takeoff, among the heat generated by the battery 14 during takeoff and the heat generated by the battery 14 during landing. The phase transition temperature of the latent heat storage material 1711B is set so as to absorb the heat generated by the battery 14 during landing, among the heat generated by the battery 14 during takeoff and the heat generated by the battery 14 during landing. The latent heat storage material 1711A corresponds to the first latent heat storage material, and the latent heat storage material 1711B corresponds to the second latent heat storage material. Hereinafter, the latent heat storage material 1711A may be referred to as PCM1, and the latent heat storage material 1711B may be referred to as PCM2.

[0062] The cooling device 17 may have only the latent heat storage material 1711A or only the latent heat storage material 1711B as the latent heat storage material 1711. The cooling device 17 may have both the latent heat storage material 1711A and the latent heat storage material 1711B as the heat storage material 171.

[0063] In a configuration in which the latent heat storage material 1711 is disposed on the side surfaces 1423, for example, as shown in Fig. 6, the latent heat storage material 1711 may have a two-layer structure between the side surfaces 1423 of adjacent battery cells 142. Two types of latent heat storage materials 1711A and 1711B are laminated and disposed in the X direction between the side surfaces 1423 facing each other. The latent heat storage material 1711A contacts one side surface 1423 of the battery cell 142, and the latent heat storage material 1711B contacts the other side surface 1423 of the battery cell 142. Each of the latent heat storage materials 1711A and 1711B contacts almost the entire area of ​​the corresponding side surface 1423.

[0064] As shown in Fig. 7, the latent heat storage material 1711 may have a three-layer structure between the side surfaces 1423. In Fig. 7, the latent heat storage material 1711A, the latent heat storage material 1711B, and the latent heat storage material 1711A are laminated in this order in the X direction. One of the latent heat storage materials 1711A contacts one of the side surfaces 1423 of the battery cell 142, and the other of the latent heat storage materials 1711A contacts the other of the side surfaces 1423 of the battery cell 142. The latent heat storage material 1711B is thermally connected to the battery cell 142 via the latent heat storage material 1711A.

[0065] As shown in Fig. 8, the latent heat storage material 1711 may have a three-layer structure between the side surfaces 1423. In Fig. 8, the latent heat storage material 1711B, the latent heat storage material 1711A, and the latent heat storage material 1711B are laminated in this order in the X direction. One of the latent heat storage materials 1711B contacts one side surface 1423 of the battery cell 142, and the other of the latent heat storage materials 1711B contacts the other side surface 1423 of the battery cell 142. The latent heat storage material 1711A is thermally connected to the battery cell 142 via the latent heat storage material 1711B.

[0066] 9, the latent heat storage materials 1711A and 1711B may be alternately disposed in the Z direction between the side surfaces 1423. The latent heat storage materials 1711A and 1711B are in contact with both side surfaces 1423, respectively.

[0067] As shown in Fig. 10, the latent heat storage material 1711A and the latent heat storage material 1711B may be placed between the side surfaces 1423 in a capsule-containing state. The latent heat storage material 1711A and the latent heat storage material 1711B are contained in different capsules. The two types of capsules may be contained in a common container, or may be held in a common matrix. They may be molded integrally with a binder or the like. The two types of capsules may be arranged in layers as shown in Fig. 10, or may be dispersed and mixed.

[0068] 6 to 10 show an example in which two types of latent heat storage materials 1711A and 1711B are arranged between the side surfaces 1423. Alternatively, as shown in Fig. 11, the latent heat storage material 1711A may be arranged on one of the side surfaces 1423 of a common battery cell 142, and the latent heat storage material 1711B may be arranged on the other of the side surfaces 1423. The latent heat storage material 1711A contacts one of the side surfaces 1423 in the X direction, and the latent heat storage material 1711B contacts the side surface 1423 opposite to the latent heat storage material 1711A. In this case, each of the latent heat storage materials 1711A and 1711B absorbs heat from one surface.

[0069] 6 to 11 show an example in which two types of latent heat storage materials 1711A and 1711B are arranged. Alternatively, as shown in Fig. 12, only latent heat storage material 1711A may be arranged between side surfaces 1423 of adjacent battery cells 142. As shown in Fig. 13, only latent heat storage material 1711B may be arranged between side surfaces 1423.

[0070] <Battery temperature and latent heat storage material> FIG. 14 is a diagram showing the relationship between the battery temperature and PCM1 during flight. FIG. 15 is a diagram showing the relationship between the battery temperature and PCM2 during flight. FIG. 16 is a diagram showing the relationship between the battery temperature and PCM1 and PCM2 during flight. In FIGS. 14 to 16, the total amount of latent heat storage material 1711 is constant. FIG. 14 shows the effect of PCM1. FIG. 15 shows the effect of PCM2. FIG. 16 shows the effect of combining PCM1 and PCM2. In FIG. 16, the amount of each of PCM1 and PCM2 is set to 1 / 2 of the total amount.

[0071] In FIGS. 14 to 16, the change in the battery temperature in the case without a PCM (latent heat storage material 1711) is shown by a dashed line as a comparative example. Time tm1 indicates the takeoff start timing, and time tm2 indicates the timing of the temperature change accompanying the switch from the takeoff operation to the cruise operation. Time tm3 indicates the timing of the temperature change accompanying the switch from the cruise operation to the landing operation, and time tm4 indicates the landing completion timing. Temperature Ta is the ambient temperature, and temperature Tmax is the allowable upper limit temperature. Temperature Tc1 indicates the phase transition temperature of PCM1, and temperature Tc2 indicates the phase transition temperature of PCM2. The temperatures are in the relationship of Ta < Tc1 < Tc2 < Tmax.

[0072] As described above, a high-output load is applied to the battery 14 during takeoff and landing. Therefore, when the PCM (latent heat storage material 1711) is not used, as shown by the dashed line in FIG. 14, the battery temperature rapidly rises between time tm1 and time tm2 and between time tm3 and time tm4. Between time tm2 and time tm3, the battery temperature changes due to the balance between the heat generation of the battery 14 accompanying the cruise operation and the heat dissipation due to the difference from the ambient temperature Ta. As an example, in FIG. 14, it rises with a gentler slope compared to takeoff and landing. The battery temperature is higher at landing than at takeoff.

[0073] PCM1 absorbs the heat generation of the battery 14 accompanying takeoff. When PCM1 (latent heat storage material 1711A) is used, as shown by the solid line in FIG. 14, when the battery temperature rises to the phase transition temperature Tc1, it is held near the phase transition temperature Tc1. In FIG. 14, the amount of PCM1 is set so that the phase change of PCM1 is completed by absorbing the heat generation of the battery accompanying the output load at takeoff. For this reason, after time tm2, the battery temperature rises. Since the battery temperature is low and the difference from the ambient temperature Ta is smaller than in the comparative example, between time tm2 and time tm3, the battery temperature rises with a steeper slope than in the case without a PCM. However, since it is during cruising, the slope is smaller than that at takeoff and landing. Between time tm3 and time tm4, the battery temperature changes (rises) in the same manner as in the comparative example.

[0074] ΔT1 indicates the difference in battery temperature at the time of landing completion compared to the comparative example, that is, the effect of temperature reduction by the latent heat storage material 1711A (latex heat storage material 1711). When PCM1 (latex heat storage material 1711A) is used, the frequency of low temperatures during flight can be increased.

[0075] In Fig. 15, the change in battery temperature when only PCM1 (latent heat storage material 1711A) is used is shown by a dashed line as a comparative example. PCM2 absorbs heat generated by the battery 14 during landing. When PCM2 (latent heat storage material 1711B) is used, as shown by a solid line in Fig. 15, the battery temperature changes in the same manner as the comparative example without a PCM, shown by a dashed line, until it reaches phase transition temperature Tc2. From when phase transition temperature Tc2 is reached until time tm4, that is, until landing is completed, the battery temperature is maintained near phase transition temperature Tc2.

[0076] ΔT2 indicates the temperature difference with the ambient temperature Ta, that is, the effect of temperature reduction due to heat dissipation. When PCM2 (latent heat storage material 1711B) is used, the temperature difference with the ambient temperature Ta between time tm2 and time tm3 is larger than when PCM1 is used. This promotes heat dissipation. In addition to the above-mentioned ΔT1, the effect of ΔT2 is exerted, so that the temperature reached at the time of completion of landing can be further reduced.

[0077] In addition, the frequency of high temperatures during voyage increases, which provides the following benefits: Battery performance can be maintained due to the heat retention effect during cold weather cruising. The ion fluidity in the electrolyte is increased, which reduces temporary deterioration of the battery 14 due to temporary bias in the ion concentration distribution. In addition, the increase in resistance in a low SOC state can be reduced.

[0078] In FIG. 16, the change in battery temperature when only PCM1 (latent heat storage material 1711A) is used as a comparative example is shown by a dashed line, and the change in battery temperature when only PCM2 (latent heat storage material 1711B) is used is shown by a two-dot dashed line. When PCM1 and PCM2 are used, the characteristics of both appear in the change in battery temperature. As shown by the solid line in FIG. 16, when the battery temperature rises to the phase transition temperature Tc1, it is maintained near the phase transition temperature Tc1. However, since the amount of PCM1 is small, the phase change of PCM1 is completed before time tm2, and the battery temperature rises. In other words, PCM1 absorbs part of the heat generated by the battery 14 during takeoff.

[0079] As a result, the battery temperature at time tm2 is intermediate between the case of only PCM1 and the case of only PCM2. The heat dissipation effect is also intermediate, and the slope of the battery temperature from time tm2 to time tm3 is intermediate between the case of only PCM1 and the case of only PCM2. The battery temperature at time tm3 is intermediate between the case of only PCM1 and the case of only PCM2. The phase transition temperature Tc2 is reached later than in the case of only PCM2. However, since the amount of PCM2 is small, the phase change of PCM2 is completed before time tm4, and the battery temperature rises. The PCM2 absorbs part of the heat generated by the battery 14 during landing. ΔT2 is smaller than when PCM2 is used. The ratio of PCM1 to PCM2 is not limited to 1:1. The amount of PCM1 may be increased, or the amount of PCM2 may be increased.

[0080] <Summary of the First Embodiment> As described above, a high output load is applied to the battery 14 during takeoff and landing of the eVTOL 10. In the cooling device 17 of this embodiment, the phase transition temperature of the latent heat storage material 1711 is set with a focus on takeoff and landing, when heat generation in the battery 14 increases rapidly. The phase transition temperature of the latent heat storage material 1711A (PCM1, first latent heat storage material) is set so as to absorb heat generation in the battery 14 accompanying takeoff. The phase transition temperature of the latent heat storage material 1711B (PCM2, second latent heat storage material) is set so as to absorb heat generation in the battery 14 accompanying landing. The cooling device 17 includes the latent heat storage material 1711A and / or the latent heat storage material 1711B as the latent heat storage material 1711 that utilizes latent heat.

[0081] Because the heat of the battery 14 is effectively absorbed by utilizing latent heat during high output load, deterioration of the battery life due to heat absorption not being able to keep up can be suppressed. In other words, the life of the battery 14 can be extended. It is possible to suppress output stop of the battery 14 due to an abnormality of excessive temperature rise. In addition, it is possible to reduce the weight compared to a configuration that uses only sensible heat for cooling.

[0082] In particular, when the latent heat storage material 1711A is used, as shown in FIG. 14, the frequency of low temperatures during flight can be increased. Therefore, the effect of extending the life of the battery 14 can be improved. When the latent heat storage material 1711B is used, as shown in FIG. 15, the frequency of high temperatures increases, so that the heat dissipation proceeds due to the difference with the environmental temperature Ta, and the end temperature can be lowered. Therefore, the amount of the latent heat storage material 1711B can be reduced for a predetermined end temperature, and weight can be further reduced. When the latent heat storage material 1711A and the latent heat storage material 1711B are used, as shown in FIG. 16, an effect according to the amount (ratio) of the latent heat storage material 1711A and the latent heat storage material 1711B is achieved. In other words, it is possible to adjust to various needs from various perspectives such as battery life, weight reduction, and even safety, depending on the takeoff and landing load (aircraft type), cruising load (flight distance), and environmental conditions (region, season), etc. As described above, by selecting the latent heat storage material 1711A (PCM1) and the latent heat storage material 1711B (PCM2), various needs of eVTOL10 can be met.

[0083] The total amount of heat stored in the heat storage material 171 for absorbing heat from the battery 14 should be set based on the amount of heat stored at the start of flight, the output load during flight, and the heat dissipation characteristics of the battery 14 so that the battery temperature during flight is equal to or lower than the upper limit temperature for use. This allows the battery to be cooled during flight using only the heat storage material 171, thereby making it possible to reduce the weight.

[0084] The amount of latent heat storage material 1711 may be set so that the phase change of latent heat storage material 1711 is completed by absorbing heat generated by battery 14 due to output load during flight. Weight can be reduced by eliminating excess latent heat storage material 1711. Furthermore, when all of latent heat storage material 1711 has undergone phase change, the temperature gradient (inclination) of the battery becomes steep. It is possible to know from the temperature change that the remaining amount of heat stored in latent heat storage material 1711 has become zero. This makes it possible to take measures such as limiting output, for example.

[0085] The amount of latent heat storage material 1711 may be set so that an incomplete phase change portion remains in latent heat storage material 1711 due to the absorption of heat generated by battery 14 accompanying output load during flight. This can prevent temperature unevenness (temperature variation) from occurring or increasing in battery 14 due to the inability of the battery to absorb the sudden heat generated by battery 14 due to high output load during takeoff. As a result, it is possible to hasten the start of charging on the ground. Also, by leaving a portion of latent heat storage material 1711 in a solid state, the effect of preventing supercooling can be enhanced.

[0086] Second embodiment This embodiment is a modified example based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, a latent heat storage material is provided as the heat storage material. Instead of this, a fluid heat storage material may be provided together with the latent heat storage material as the heat storage material.

[0087] Fig. 17 shows the cooling device 17 according to this embodiment. Fig. 17 corresponds to Fig. 2. Fig. 17 shows the relationship between the cooling device 17 and the battery 14. As shown in Fig. 17, the cooling device 17 includes a latent heat storage material (PCM) 1711 and a flowable heat storage material (FHS) 1712 as a heat storage material 171. The flowable heat storage material 1712 is a heat storage material having flowability, and is thermally connected to the latent heat storage material 1711.

[0088] The fluid heat storage material 1712 absorbs heat from the latent heat storage material 1711 by utilizing sensible heat. The fluid heat storage material 1712 may absorb heat from the battery 14. Any appropriate fluid such as a gas or liquid may be used as the fluid heat storage material 1712. For example, water, cooling water to which LLC has been added, refrigerant, oil, air, etc. may be used. LLC is an abbreviation for Long Life Coolant.

[0089] In order to repeatedly use the cooling device 17 equipped with the latent heat storage material 1711 at a high operating rate, it is essential to efficiently regenerate the latent heat storage material 1711 that absorbs heat from the battery cells 142. Regeneration refers to returning the latent heat storage material 1711 that has undergone a phase transition due to heat absorption to the state before the phase transition, for example, returning it from a liquid to a solid. For this reason, it is necessary to incorporate a regeneration function that is thermally connected to the latent heat storage material 1711 and actively absorbs heat from the latent heat storage material 1711.

[0090] 17, in order to regenerate the latent heat storage material 1711, the latent heat storage material 1711 and the fluid heat storage material 1712 may be provided separately. The sensible heat of the fluid heat storage material 1712 is utilized to absorb heat from the latent heat storage material 1711, and the latent heat storage material 1711 can be regenerated. The fluid heat storage material 1712 assists the latent heat storage material 1711 in absorbing heat from the battery cells 142 by the latent heat storage material 1711 through regeneration of the latent heat storage material 1711. The fluid heat storage material 1712 absorbs heat from the battery cells 142 directly or indirectly via the latent heat storage material 1711. The cooling device 17 performs hybrid cooling using the latent heat storage material 1711 and the fluid heat storage material 1712.

[0091] As a configuration in which the latent heat storage material 1711 and the fluidity storage material 1712 are provided separately, a configuration similar to that shown in the preceding embodiment (see FIGS. 6 to 9) may be adopted. For example, the latent heat storage material 1711 and the fluidity storage material 1712 may be disposed between the side surfaces 1423 of adjacent battery cells 142. The latent heat storage material 1711 and the fluidity storage material 1712 may be disposed on a common side surface 1423, or on different side surfaces 1423.

[0092] 18, for example, a latent heat storage material 1711 and a fluid heat storage material 1712 may be disposed between side surfaces 1423. A latent heat storage material 1711 is disposed on each of the opposing side surfaces 1423, and a fluid heat storage material 1712 is disposed between the latent heat storage materials 1711. Each layer of the latent heat storage material 1711 may be composed of only a latent heat storage material (PCM1) 1711A, or may be composed of only a latent heat storage material (PCM2) 1711B. It may also be composed of both latent heat storage materials 1711A and 1711B.

[0093] 19, the latent heat storage material 1711 and the fluid heat storage material 1712 may be alternately arranged in the Z direction between the side surfaces 1423. The latent heat storage material 1711 may be composed of only the latent heat storage material (PCM1) 1711A, or may be composed of only the latent heat storage material (PCM2) 1711B. It may also be composed of both the latent heat storage materials 1711A and 1711B.

[0094] FIG. 20 shows another example of the cooling device 17. FIG. 20 corresponds to FIG. 17. For regenerating the latent heat storage material 1711, as shown in FIG. 20, a mixed heat storage material (MHS) 1713 obtained by mixing the latent heat storage material 1711 and the fluid heat storage material 1712 may be used. The mixed heat storage material 1713 is a mixed heat storage material having fluidity by dispersing the latent heat storage material 1711 in the fluid heat storage material 1712. In the case of the latent heat storage material 1711 that undergoes a phase transition from solid to liquid, as shown in FIG. 21, the latent heat storage material 1711 filled in a capsule may be dispersed and mixed in the fluid heat storage material 1712. In FIG. 21, the mixed heat storage material 1713 is disposed between the side surfaces 1423. In the case of the latent heat storage material 1711 that undergoes a phase transition from solid to solid, the powder-like latent heat storage material 1711 may be dispersed and mixed in the fluid heat storage material 1712.

[0095] The fluid heat storage material 1712 and the mixed heat storage material 1713 may be sealed in a predetermined container. As shown in FIG. 22, the cooling device 17 may include a flow mechanism 172, and the fluid heat storage material 1712 and / or the mixed heat storage material 1713 may be caused to flow by the flow mechanism 172. The fluid heat storage material 1712 and / or the mixed heat storage material 1713 may be referred to as a fluid medium. The flow mechanism 172 has a cooler 1721, a pump (P) 1722, and a pipe 1723. The cooler 1721 is filled with the fluid medium and is thermally connected to the battery 14. For example, a metallic container having a flow path may be used as the cooler 1721, or a metallic cooling plate having a flow path may be used. The pump 1722 controls the flow of the fluid medium. For example, a circulation pump that circulates the fluid medium may be used as the pump 1722, or a reciprocating pump that reciprocates the fluid medium may be used. The pipe 1723 connects the cooler 1721 and the pump 1722. The fluid medium also flows inside the pipe 1723. As an example, Fig. 21 shows a configuration in which the fluid medium is circulated.

[0096] The location of the pump 1722 is not particularly limited. It may be inside or outside the cooling device 17. A pump of a device other than the cooling device 17 may be used. In FIG. 22, an example of the fluid heat storage material 1712 is shown as the fluid medium, but this is not limiting. The flow mechanism 172 may be applied to the configuration shown in FIG. 20. That is, the mixed heat storage material 1713 may be caused to flow by the flow mechanism 172. The other configurations are similar to those described in the preceding embodiment.

[0097] <Summary of the second embodiment> According to this embodiment, in addition to the effects described in the preceding embodiment, the following effects are achieved. The heat storage material 171 of this embodiment includes a fluid heat storage material 1712 in addition to the latent heat storage material 1711. The fluid heat storage material 1712 is thermally connected to the latent heat storage material 1711. Therefore, the sensible heat of the fluid heat storage material 1712 can be used to absorb heat from the latent heat storage material 1711 and regenerate the latent heat storage material 1711. Therefore, the effect of heat absorption by latent heat can be enhanced. For example, the period during which the temperature is held near the phase transition temperature can be extended. For example, the amount of the latent heat storage material 1711 required to hold the temperature near the phase transition temperature can be reduced. In addition, the sensible heat of the fluid heat storage material 1712 can be used to absorb heat generated by the battery 14 during cruising that cannot be absorbed by latent heat. In other words, heat absorption during cruising can be strengthened.

[0098] When the mixed heat storage material 1713 is used, the latent heat storage material 1711 flows together with the fluid heat storage material 1712. Therefore, the heat storage state of the multiple types of heat storage materials 171 including the latent heat storage material 1711 can be homogenized by natural convection or forced flow.

[0099] The cooling device 17 may include the flow mechanism 172 as described above. By including the flow mechanism 172, the flow medium can be made to flow during flight. Therefore, when the flow medium is the flowable heat storage material 1712, the unevenness of the heat storage state of the flowable heat storage material 1712 can be eliminated, and the heat absorption capacity from the latent heat storage material 1711 and the battery 14 can be used up without impairing the medium. When the flowable medium is the mixed heat storage material 1713, the unevenness of the amount of heat storage due to the segregation of the latent heat storage material 1711 can be suppressed, and the amount of heat storage can be homogenized. Therefore, the heat absorption capacity from the battery 14 can be used up without impairing the medium.

[0100] Furthermore, since the fluid medium in the pipe 1723 functions as a heat storage reserve, it is possible to lower the maximum temperature reached by the battery 14. Since heat dissipation from the fluid medium can be promoted in the pipe 1723, which has better heat dissipation properties than the inside of the battery, it is possible to lower the maximum temperature reached. Note that the flow mechanism 172 may have a reservoir for the fluid medium separate from the pipe 1723.

[0101] The configuration described in this embodiment can be combined with any of the configurations shown in the preceding embodiments.

[0102] Third embodiment This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, the cooling device includes a heat storage material. Instead of this, the cooling device may include a heat conduction auxiliary member together with the heat storage material.

[0103] The latent heat storage material 1711 is very effective in increasing heat capacity. However, because of its low thermal conductivity, it may not be able to absorb the sudden heat generated by the battery 14, which may cause temperature unevenness. In particular, the latent heat storage material 1711, which undergoes a phase change between solid and liquid, may cause temperature unevenness. Therefore, in applications where it is desired to rapidly absorb heat in a predetermined temperature range, such as during takeoff and landing, it is advisable to impart a thermal conductivity auxiliary function to the latent heat storage material 1711. This improves the heat absorption responsiveness of the latent heat storage material 1711, and makes it possible to effectively utilize the large latent heat. Since the heat absorption responsiveness of the latent heat storage material 1711 is increased, it is possible to rapidly absorb heat during takeoff and landing. FIG. 23 is a diagram showing the relationship between the battery temperature and the amount of heat absorption. The dashed line indicates the case where there is no thermal conductivity auxiliary function, and the solid line indicates the case where there is a thermal conductivity auxiliary function. As shown by the white arrow, the heat absorption responsiveness of the latent heat storage material 1711 is improved by imparting a thermal conductivity auxiliary function.

[0104] The cooling device 17 of this embodiment includes a heat conduction assistant member in addition to the heat storage material 171 including the latent heat storage material 1711. The heat conduction assistant member has better thermal conductivity than the heat storage material 171. The heat conduction assistant member is disposed in contact with the heat storage material 171. As a material having good thermal conductivity, for example, a metal-based material such as aluminum or a carbon-based material may be used. A ceramic-based material such as alumina may be used. The larger the contact area between the heat conduction assistant member and the heat storage material 171, the more the heat absorption response of the heat storage material 171, particularly the heat absorption response of the latent heat storage material 1711, can be improved. The heat conduction assistant member can improve the heat absorption response of the mixed heat storage material 1713 including the latent heat storage material 1711. The heat conduction assistant member can improve the heat absorption response of the fluidity heat storage material 1712 having low thermal conductivity, such as water.

[0105] The thermal conduction assistant member can be in various forms. For example, as shown in Fig. 24, a thermally conductive filler 1731 may be used as the thermal conduction assistant member 173, and the thermally conductive filler 1731 may be mixed and dispersed in the latent heat storage material 1711. The thermally conductive filler 1731 may be, for example, a metal-based filler or a carbon-based filler. As shown in Fig. 25, a capsule 1733 containing particles 1732 with excellent thermal conductivity may be used as the thermal conduction assistant member 173. The resin wall of the capsule 1733 contains the particles 1732. Figs. 24 and 25 are diagrams showing an example of a thermal conduction assistant member.

[0106] Although not shown, fins, ribs, beams, etc. may be provided inside the container (cooling member) that contains the heat storage material 171 to enhance thermal conductivity and serve as a heat conduction auxiliary member. A matrix formed of a material with excellent thermal conductivity may be used as the heat conduction auxiliary member, and the latent heat storage material may be held within the matrix. The heat conduction auxiliary member may be a combination of the above examples. The other configurations are the same as those shown in the preceding embodiment.

[0107] <Summary of the third embodiment> According to this embodiment, the cooling device 17 has a higher thermal conductivity than the heat storage material 171 and includes a heat conduction auxiliary member 173 arranged in contact with the heat storage material 171. This allows the heat absorption responsiveness to be improved even if the heat conductivity of the heat storage material 171 is low. Therefore, the large heat generation during takeoff and landing can be absorbed quickly and with reduced temperature variation. In other words, the heat generation of the battery 14 accompanying takeoff and landing can be absorbed, and the effect of extending the battery life can be improved. By including the heat conduction auxiliary member 173, the heat absorption performance can be exhibited without impairing the heat responsiveness even if multiple types of heat storage materials 171 are layered and mixed.

[0108] A thermally conductive filler 1731 may be used as the thermal conduction assistant member 173, and the thermally conductive filler 1731 may be dispersed and mixed in the heat storage material 171. By dispersing and mixing at the material level, the contact area between the heat storage material 171 and the thermally conductive filler 1731 (thermal conduction assistant member 173) can be further increased. Therefore, the thermal response can be further improved. For example, the thermally conductive filler 1731 may be dispersed and mixed in particles of the latent heat storage material 1711 that changes phase between solid phases, and molded. The thermally conductive filler 1731 may be dispersed and mixed in the latent heat storage material 1711 that changes phase between solid phase and liquid phase, and contained in a capsule.

[0109] A capsule 1733 may be used as the thermal conduction assistant member 173, and the latent heat storage material 1711 may be accommodated in the capsule 1733. By integrating the function with the capsule 1733, it is possible to improve thermal responsiveness while suppressing an increase in the required volume.

[0110] The configuration described in this embodiment can be combined with any of the configurations shown in the preceding embodiments.

[0111] (Fourth embodiment) This embodiment is a modified example based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, the latent heat storage material is arranged for the battery cell. In addition to this, the amount of latent heat storage per heat absorption area may be varied.

[0112] As described above, the temperature of the battery 14 rises rapidly during takeoff and landing. The temperature of the battery 14 varies among any one battery cell 142. The temperature difference occurs within the battery module 141, which is a battery assembly. In this manner, a high output load causes a temperature distribution in the battery 14. In this embodiment, the battery module 141 is arranged with a difference in the amount of latent heat storage per heat absorption area so as to eliminate the temperature difference that occurs inside the battery module 141 during takeoff and landing. The amount of latent heat storage per heat absorption area may be adjusted by the amount of latent heat storage material 1711, or may be adjusted by the type of latent heat storage material 1711. It may be adjusted by both the amount and type of latent heat storage material 1711.

[0113] As described above, due to the high output load during takeoff and landing, current concentrates near the electrode terminals 142P, 142N of the battery cell 142. In other words, the temperature is likely to become high near the electrode terminals 142P, 142N. Therefore, the latent heat storage material 1711 may be arranged so that the amount of the latent heat storage material 1711 at a first position on the side surface 1423 of the battery cell 142 is greater than the amount of the latent heat storage material 1711 at a second position that is farther from the electrode terminals 142P, 142N than the first position.

[0114] For example, as shown in Fig. 26, the volume of the latent heat storage material 1711 arranged between the side surfaces 1423 of adjacent battery cells 142 may be varied depending on the distance to the electrode terminals 142P, 142N in the Z direction. In Fig. 26, the filling rate is kept constant and the volume of the latent heat storage material 1711 is set in four stages (four levels), with the volume of the latent heat storage material 1711 being larger closer to the electrode terminals 142P, 142N. The volume of the latent heat storage material 1711 is larger closer to the end surface 1421, and the volume of the latent heat storage material 1711 is smaller closer to the end surface 1422.

[0115] As shown in Fig. 27, the filling rate of the latent heat storage material 1711 arranged between the side surfaces 1423 may be varied depending on the distance from the electrode terminals 142P, 142N in the Z direction. In Fig. 26, the filling rate of the latent heat storage material 1711 is set in four stages with the volume kept constant, and the filling rate of the latent heat storage material 1711 is higher the closer to the electrode terminals 142P, 142N. The filling rate of the latent heat storage material 1711H is the highest, and the relationship of latent heat storage material 1711H>latent heat storage material 1711M2>latent heat storage material 1711M1>latent heat storage material 1711L is satisfied. The filling rate of the latent heat storage material 1711 is higher the closer to the end surface 1421, and the filling rate of the latent heat storage material 1711 is lower the closer to the end surface 1422.

[0116] As shown in FIG. 28, in a mixed heat storage material 1713 containing a latent heat storage material 1711 filled in capsules, the filling rate of the latent heat storage material 1711 may be varied depending on the distance from the electrode terminals 142P, 142N in the Z direction. In FIG. 28, the filling rate of the latent heat storage material 1711 in the fluid heat storage material 1712 is set in four stages, and the filling rate of the latent heat storage material 1711 is higher as it is closer to the electrode terminals 142P, 142N. The number of capsules per unit volume is greater as it is closer to the electrode terminals 142P, 142N. The filling rate of the latent heat storage material 1711 is higher as it is closer to the end surface 1421, and the filling rate of the latent heat storage material 1711 is lower as it is closer to the end surface 1422. As shown in FIG. 28, in a container that holds the fluid heat storage material 1712, the storage space of the fluid heat storage material 1712 may be divided into four.

[0117] 26 to 28 show an example in which the electrode terminals 142P and 142N are provided on the end surface 1421 side. A similar configuration can be adopted in a configuration in which the electrode terminals 142P and 142N are provided on the end surfaces 1421 and 1422, respectively. For example, as shown in FIG. 29, the volume of the latent heat storage material 1711 may be varied depending on the distance from the electrode terminals 142P and 142N in the Z direction. In FIG. 29, the volume of the latent heat storage material 1711 is set to be constant and is set in four stages as in FIG. 26. The volume of the latent heat storage material 1711 is larger as it is closer to the electrode terminals 142P and 142N. The volume of the latent heat storage material 1711 is larger as it is closer to the end surfaces 1421 and 1422, and the volume of the latent heat storage material 1711 is smaller as it is closer to the center position of the latent heat storage material 1711 in the Z direction.

[0118] As shown in Fig. 30, the filling rate of the latent heat storage material 1711 may be varied depending on the distance from the electrode terminals 142P, 142N in the Z direction. In Fig. 30, the volume is kept constant and the filling rate of the latent heat storage material 1711 is set in four stages as in Fig. 27. The filling rate of the latent heat storage material 1711 is higher closer to the electrode terminals 142P, 142N. The filling rate of the latent heat storage material 1711 is higher closer to the end faces 1421, 1422, and the filling rate of the latent heat storage material 1711 is lower closer to the center position of the latent heat storage material 1711 in the Z direction.

[0119] As shown in Fig. 31, in a mixed heat storage material 1713 containing latent heat storage material 1711 filled in capsules, the filling rate of the latent heat storage material 1711 may be varied depending on the distance from the electrode terminals 142P, 142N in the Z direction. In Fig. 31, the filling rate of the latent heat storage material 1711 in the fluid heat storage material 1712 is set in four stages as in Fig. 28. The filling rate of the latent heat storage material 1711 is higher closer to the electrode terminals 142P, 142N. The filling rate of the latent heat storage material 1711 is higher closer to the end faces 1421, 1422, and the filling rate of the latent heat storage material 1711 is lower closer to the center position of the latent heat storage material 1711 in the Z direction.

[0120] 26 to 31 are diagrams corresponding to FIG. 4. Although an example in which the volume and the filling rate of the latent heat storage material 1711 are changed in four stages has been shown, this is not limited thereto. As long as there are multiple stages, there may be two stages, three stages, or five stages or more. The volume and the filling rate may change continuously depending on the distance from the electrode terminals 142P and 142N. In the examples shown in FIG. 26, FIG. 27, FIG. 30, and FIG. 31, the fluidity storage material 1712 may be disposed as shown in the preceding embodiment. The fluidity storage material 1712 may be disposed in the empty space between the side surfaces 1423, or may be disposed on the other side surface 1423. The latent heat storage material 1711 may be divided into two layers, and the fluidity storage material 1712 may be disposed between them. 26 to 31 show an example of latent heat storage material 1711 arranged between side surfaces 1423 of adjacent battery cells 142, but the volume and filling rate may be adjusted in a similar manner in a side surface 1423 that is not opposed to another side surface 1423.

[0121] In the battery module 141 including the plurality of battery cells 142, heat dissipation proceeds from the outer periphery of the arrangement area of ​​the plurality of battery cells 142. Therefore, due to a high output load during takeoff or landing, the temperature is likely to become high near the center of the arrangement area of ​​the plurality of battery cells 142. Therefore, in the arrangement area of ​​the plurality of battery cells 142 in the battery module 141, the latent heat storage material 1711 may be arranged so that the amount of the latent heat storage material 1711 arranged at a first position is greater than the amount of the latent heat storage material 1711 arranged at a second position that is farther from the center of the arrangement area than the first position. The center of the arrangement area is, for example, the center in the stacking direction in the stacked arrangement of the plurality of battery cells 142, and is, for example, the central position of the plurality of battery cells 142 in a planar view in a staggered arrangement of the plurality of battery cells 142.

[0122] For example, as shown in Fig. 32, in a battery module 141 including a stack in which latent heat storage materials 1711 and battery cells 142 are alternately arranged, the volume of the latent heat storage material 1711 may be varied depending on the distance from the center in the stacking direction. In Fig. 32, the filling rate is kept constant and the volume of the latent heat storage material 1711 is set in four stages (four levels), and the volume of the latent heat storage material 1711 is larger the closer it is to the center of the multiple battery cells 142 in the stacking direction.

[0123] As shown in Fig. 33, in a battery module 141 including a stack in which latent heat storage materials 1711 and battery cells 142 are alternately arranged, the filling rate of the latent heat storage material 1711 may be varied according to the distance from the center in the stacking direction. In Fig. 33, the filling rate of the latent heat storage material 1711 is set in five stages (five levels) with the volume kept constant, and the filling rate of the latent heat storage material 1711 is higher the closer to the center of the battery cells 142 in the stacking direction. The filling rate of the latent heat storage material 1711H is the highest, and the relationship of latent heat storage material 1711H>latent heat storage material 1711M3>latent heat storage material 1711M2>latent heat storage material 1711M1>latent heat storage material 1711L is satisfied.

[0124] The volume and the number of stages of the packing rate of the latent heat storage material 1711 are not limited to the examples shown in Fig. 32 and Fig. 33. The volume and the packing rate may change continuously according to the distance from the center. In the examples shown in Fig. 32 and Fig. 33, the fluid heat storage material 1712 may be arranged as shown in the preceding embodiment.

[0125] <Summary of the Fourth Embodiment> According to this embodiment, in order to eliminate the temperature difference occurring inside the battery module 141 (battery assembly), the latent heat storage material 1711 is arranged in the battery module 141 with a difference in the amount of latent heat storage per heat absorption area for the battery module 141. This makes it possible to equalize the temperature distribution in the battery cells 142 and the battery module 141 that becomes apparent due to the high output load during takeoff and landing. This makes it possible to prevent localized overheating and suppress the acceleration of battery deterioration.

[0126] The amount of latent heat storage material, for example, the volume or filling rate may be varied to provide a difference in the amount of latent heat storage per heat absorption area. By changing the type of latent heat storage material 1711, the amount of latent heat storage per heat absorption area may be varied.

[0127] The amount of latent heat storage material 1711 arranged on the side surface 1423 of the battery cell 142 may be greater at a first position on the side surface 1423 than at a second position that is farther away from the electrode terminals 142P, 142N than the first position. By increasing the amount of latent heat storage in the side surface portion close to the electrode terminals 142P, 142N of the battery cell 142, which is prone to localized temperature increases due to high output loads during takeoff and landing, it is possible to more easily uniform the temperature distribution.

[0128] In an arrangement region of a plurality of battery cells 142 in a battery module 141, the amount of latent heat storage material 1711 arranged at a first position may be greater than the amount of latent heat storage material 1711 arranged at a second position that is farther from the center of the arrangement region than the first position. By increasing the amount of latent heat storage near the center of the arrangement region of the battery cells 142, where the temperature is likely to rise locally due to high output loads during takeoff and landing, it is possible to more easily uniform the temperature distribution.

[0129] The configuration described in this embodiment can be combined with any of the configurations shown in the preceding embodiments.

[0130] Fifth embodiment This embodiment is a modified example based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, a configuration in which the battery is cooled by an internal cooling device is shown. In addition to this, a configuration in which cooling by an external cooling device is possible may be used.

[0131] FIG. 34 shows the cooling device 17 and the cooling system 50 according to this embodiment. FIG. 34 corresponds to FIG. 22. As shown in FIG. 34, the cooling device 17 includes a fluid heat storage material 1712, which is a fluid medium, and a joint 18 for connecting to an external cooling device (EC) 40 on the ground. Hereinafter, the cooling device 17 may be referred to as an on-board cooling device. The joint 18 connects a flow mechanism 172 of the on-board cooling device 17 to the external cooling device 40. The pipes of the cooling device 17 and the external cooling device 40 are connected to each other via the joint 18. The joint 18 may be separate from the cooling device 17. The joint 18 may be integrated with the airframe.

[0132] The off-board cooling device 40 includes a heat exchanger, a pump, piping, and the like (not shown). The off-board cooling device 40 is connected to the joint 18 on the ground. The off-board cooling device 40 causes the fluid heat storage material 1712 to flow through the joint 18. The off-board cooling device 40 may circulate the fluid heat storage material 1712, for example. The cooled fluid heat storage material 1712 is returned to the aircraft by heat exchange in the off-board cooling device 40, and the latent heat storage material 1711 and the battery 14 are also cooled. The cooling system 50 includes the on-board cooling device 17 arranged on the eVTOL 10, and the off-board cooling device 40. The cooling system 50 that cools the battery 14 has a part of its functions arranged on the aircraft and another part of its functions arranged outside the aircraft.

[0133] Fig. 35 shows the relationship between the cooling system and other devices. The BMS 16 acquires information on the battery cells 142 from the battery modules 141. As shown in Fig. 35, the BMS 16 may have a function of monitoring the cooling device 17 and a function of controlling the cooling device 17 (flow mechanism 172). The function of monitoring the cooling device 17 and the function of controlling the cooling device 17 (flow mechanism 172) may be provided separately from the BMS 16.

[0134] The operation control device (OCD) 60 is connected to the BMS 16, the external cooling device 40, and the charging device (CD) 70 so as to be able to communicate with them. Some of the functions of the operation control device 60 may be arranged inside the aircraft, and other parts of the functions may be arranged outside the aircraft. As described above, the functions of the operation control device 60 may be arranged only inside the aircraft, or only outside the aircraft. The functions of the BMS 16, the operation control device 60, and the cooling device 17 may be appropriately shared. The external cooling device 40 and the charging device 70 may be provided separately as shown in FIG. 35, or may be integrated. The external cooling device 40 may cool the fluid heat storage material 1712, the latent heat storage material 1711, and the battery 14 at the timing of charging the battery 14 by the charging device 70. The dashed lines shown in FIG. 35 indicate power lines.

[0135] 34 and 35 show an example of the fluid heat storage material 1712 as the fluid medium, but the fluid medium is not limited to this. The mixed heat storage material 1713 may be applied to the cooling device 17 and the cooling system 50 having the joint 18.

[0136] <Summary of the Fifth Embodiment> According to this embodiment, the cooling device 17 includes a joint 18 for connecting the fluid medium to the off-board cooling device 40 on the ground. The cooling device 17 and the off-board cooling device 40 form a cooling system 50. The off-board cooling device 40 cools the heat storage material 171 and the battery 14 by fluidizing the fluid medium. This makes it possible to adjust the battery temperature and the heat storage state of the latent heat storage material 1711 to a state that allows the next flight. Forced cooling by the off-board cooling device 40 makes it possible to absorb heat from the battery cells 142 and the latent heat storage material 1711 that has stored heat in a short period of time.

[0137] <Modification> Although an example has been shown in which the external cooling device 40 is connected to the cooling device 17 including the fluid heat storage material 1712 as the heat storage material 171, the present invention is not limited to this. For example, as shown in FIG. 36, the external cooling device 40 may be connected to the cooling device 17 including only the latent heat storage material 1711 as the heat storage material 171. The cooling device 17 has, for example, a cooler 1721 and a pipe 1723 connecting the cooler 1721 and a joint 18. The external cooling device 40 causes the fluid heat storage material 1712 to flow through the joint 18, the internal pipe 1723, and the cooler 1721, and cools the latent heat storage material 1711 and the battery 14.

[0138] Although not shown in the drawings, the external cooling device 40 may be connected to a cooling device 17 that includes the flowable heat storage material 1712 but does not include the pump 1722 for causing the flow of the flowable heat storage material 1712 .

[0139] The configuration described in this embodiment can be combined with any of the configurations shown in the preceding embodiments.

[0140] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure includes the exemplified embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes the omission of parts and / or elements of the embodiments. The disclosure includes the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

[0141] The disclosure in the specification and drawings is not limited by the claims. The disclosure in the specification and drawings includes the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification and drawings without being bound by the claims.

[0142] When an element or layer is referred to as being "on," "coupled," "connected," or "bonded," it may be directly coupled, connected, or bonded to another element or layer, and intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly coupled," "directly connected," or "directly bonded" to another element or layer, there are no intervening elements or layers. Other words used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0143] The various flowcharts shown in this disclosure are all examples, and the number of steps constituting the flowcharts and the order of execution of the processes can be changed as appropriate. In addition, the apparatus, system, and method thereof described in this disclosure may be realized by a dedicated computer comprising a processor programmed to execute one or more functions embodied in a computer program. The apparatus and method described in this disclosure may be realized using a dedicated hardware logic circuit. Furthermore, the apparatus and method described in this disclosure may be realized by one or more dedicated computers configured by a combination of a processor executing a computer program and one or more hardware logic circuits.

[0144] For example, some or all of the functions of processor 201 may be realized as hardware. A form in which a certain function is realized as hardware includes a form in which it is realized using one or a plurality of ICs. As the processor (computation core), a CPU, MPU, GPU, DFP, etc. can be adopted. CPU is an abbreviation for Central Processing Unit. MPU is an abbreviation for Micro-Processing Unit. GPU is an abbreviation for Graphics Processing Unit. DFP is an abbreviation for Data Flow Processor.

[0145] Some or all of the functions of the processor 201 may be realized by combining a plurality of types of arithmetic processing devices. Some or all of the functions of the processor 201 may be realized by using an SoC, an ASIC, an FPGA, or the like. SoC is an abbreviation for System on Chip. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field-Programmable Gate Array. The same applies to the processor 311.

[0146] The computer program may be stored in a computer-readable non-transitory tangible storage medium as instructions executed by a computer. A HDD, SSD, flash memory, etc. may be used as a storage medium for the program. HDD is an abbreviation for Hard-disk Drive. SSD is an abbreviation for Solid State Drive. The scope of the present disclosure also includes forms such as a program for causing a computer to function as a control device or control system, and a non-transitory tangible storage medium such as a semiconductor memory on which the program is recorded.

[0147] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple dependent claims. Some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. Furthermore, some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. The claims described in these multiple dependent forms define multiple technical ideas.

[0148] <Technical philosophy 1> A cooling device mounted on an electric flying object (10) and cooling a battery (14) of the electric flying object, comprising: one or more types of heat storage material (171) that absorbs heat from the battery; The cooling device includes, as the latent heat storage material (1711), a first latent heat storage material (1711A) whose phase transition temperature is set to absorb the heat generated by the battery during takeoff and the heat generated by the battery during landing, and / or a second latent heat storage material (1711B) whose phase transition temperature is set to absorb the heat generated by the battery during takeoff and the heat generated by the battery during landing.

[0149] <Technical philosophy 2> The cooling device described in technical idea 1, wherein the heat storage material includes a fluid heat storage material (1712) thermally connected to the latent heat storage material.

[0150] <Technical philosophy 3> a mechanism (172) for flowing the fluid medium, which is the fluid heat storage material and / or a mixed heat storage material obtained by mixing the latent heat storage material and the fluid heat storage material, in the cabin of the electric flying object; The cooling device described in technical idea 2, wherein the mechanism includes a cooler (1721) filled with the fluid medium and thermally connected to the battery, a pump (1722) that controls the flow of the fluid medium, and piping (1723) that connects the cooler and the pump.

[0151] <Technical philosophy 4> The cooling device according to Technical Idea 2 or Technical Idea 3 is provided with a fitting (18) for connecting the fluid medium, which is the fluid heat storage material and / or a mixed heat storage material obtained by mixing the latent heat storage material and the fluid heat storage material, to an off-board cooling device on the ground.

[0152] <Technical philosophy 5> The cooling device according to any one of Technical Concepts 1 to 4, further comprising a heat transfer auxiliary member (173) that has a higher thermal conductivity than the heat storage material and is disposed in contact with the heat storage material.

[0153] <Technical philosophy 6> The cooling device according to Technical Idea 5, wherein the heat storage material and the heat conduction auxiliary member are dispersed and mixed.

[0154] <Technical philosophy 7> The heat conduction assistant member is a capsule, The cooling device according to Technical Idea 5, wherein the latent heat storage material is contained in the capsule.

[0155] <Technical philosophy 8> A cooling device according to any one of Technical Ideas 1 to 7, wherein the total amount of heat stored in the heat storage material for absorbing heat from the battery is set based on the amount of heat stored at the start of flight, the output load during flight, and the heat dissipation characteristics of the battery so that the battery temperature during flight is equal to or lower than the upper usage temperature.

[0156] <Technical philosophy 9> The cooling device described in Technical Idea 8, wherein the amount of the latent heat storage material is set so that the phase change of the latent heat storage material is completed by absorbing heat generated by the battery due to output load during flight.

[0157] <Technical Thought 10> The cooling device described in Technical Idea 8, wherein the amount of the latent heat storage material is set so that an incomplete phase change portion remains in the latent heat storage material due to the absorption of heat generated by the battery due to the output load during flight.

[0158] <Technical Thought 11> The battery includes a battery assembly (141) including a plurality of battery cells (142); A cooling device described in any one of Technical Ideas 1 to 10, wherein the latent heat storage material is arranged with a difference in latent heat storage amount per heat absorption area relative to the battery assembly so as to eliminate the temperature difference occurring inside the battery assembly.

[0159] <Technical Thought 12> the latent heat storage material is disposed on a side surface of the battery cell, the battery cell has electrode terminals (142P, 142N) on a surface different from the side surface; A cooling device as described in Technical Idea 11, wherein the amount of the latent heat storage material at a first position on the side surface is greater than the amount of the latent heat storage material at a second position that is farther from the electrode terminal than the first position.

[0160] <Technical Thought 13> A cooling device as described in technical idea 11, wherein in an arrangement area of ​​a plurality of the battery cells in the battery assembly, the amount of the latent heat storage material arranged at a first position is greater than the amount of the latent heat storage material arranged at a second position that is farther from the center of the arrangement area than the first position. [Explanation of symbols]

[0161] 10...eVTOL, 11...aircraft body, 12...fixed wing, 121...main wing, 122...tail, 13...rotor, 131...blade, 132...shaft, 14...battery, 141...battery module, 142...battery cell, 142N, 142P...electrode terminal, 1421, 1422...end surface, 1423...side, 15...EPU, 16...BMS, 17...cooling device (in-flight cooling device), 171...heat storage material, 1711, 1711A, 1711B...latent heat storage material, 1712...fluid heat storage material, 1713...mixed heat storage material, 172...flow mechanism, 1721... Cooler, 1722...pump, 1723...piping, 173...thermal conductive auxiliary member, 1731...thermal conductive filler, 1732...particles, 1733...capsule, 18...joint, 20...ECU, 201...processor, 202...memory, 203...storage, 203P...program, 204...communication circuit, 30...ground station, 31...server, 311...processor, 312...memory, 313...storage, 313P...program, 314...communication circuit, 40...external cooling device, 50...cooling system, 60...flight management device, 70...charging device< / evtol>

Claims

1. A cooling device mounted on an electric flying object (10) for cooling a battery (14) of the electric flying object, comprising: One or more types of heat storage materials (171) that absorb heat from the battery; The cooling device includes, as the latent heat storage material (1711), a first latent heat storage material (1711A) whose phase transition temperature is set to absorb the heat generated by the battery during takeoff and the heat generated by the battery during landing, and / or a second latent heat storage material (1711B) whose phase transition temperature is set to absorb the heat generated by the battery during takeoff and the heat generated by the battery during landing.

2. The cooling device of claim 1 , wherein the thermal storage material includes a flowable thermal storage material (1712) that is flowable and thermally connected to the latent heat storage material.

3. 3. The cooling device according to claim 1, further comprising a heat conduction assistant member (173) having a higher thermal conductivity than the heat storage material and arranged in contact with the heat storage material.

4. The heat conductive auxiliary member is a heat conductive filler (1731), The cooling device according to claim 3 , wherein the heat storage material and the thermally conductive filler are dispersed and mixed.

5. The heat conduction auxiliary member is a capsule (1733), The cooling device according to claim 3 , wherein the latent heat storage material is contained in the capsule.

6. 3. The cooling device according to claim 1 or 2, wherein a total amount of heat stored in the heat storage material for absorbing heat from the battery is set based on the amount of heat stored at the start of flight, the output load during flight, and the heat dissipation characteristics of the battery, so that the battery temperature during flight is equal to or lower than an upper usage temperature limit.

7. 7. The cooling device according to claim 6, wherein the amount of the latent heat storage material is set so that a phase change of the latent heat storage material is completed by absorbing heat generated by the battery due to an output load during flight.

8. 7. The cooling device according to claim 6, wherein the amount of the latent heat storage material is set so that an incomplete phase change portion remains in the latent heat storage material due to absorption of heat generated by the battery due to output load during flight.

9. The battery includes a battery assembly (141) including a plurality of battery cells (142); 3. The cooling device according to claim 1, wherein the latent heat storage material is arranged with a difference in latent heat storage amount per heat absorption area relative to the battery assembly so as to eliminate a temperature difference occurring inside the battery assembly.

10. the latent heat storage material is disposed on a side surface of the battery cell, The battery cell has electrode terminals (142P, 142N) on a surface different from the side surface, The cooling device according to claim 9 , wherein an amount of the latent heat storage material at a first position on the side surface is greater than an amount of the latent heat storage material at a second position that is farther away from the electrode terminal than the first position.

11. 10. The cooling device of claim 9, wherein in an arrangement area of ​​the plurality of battery cells in the battery assembly, an amount of the latent heat storage material arranged at a first position is greater than an amount of the latent heat storage material arranged at a second position that is farther from the center of the arrangement area than the first position.

12. A mechanism (172) is provided inside the electric flying object to flow the fluid medium, which is the fluid heat storage material and / or a mixed heat storage material obtained by mixing the latent heat storage material and the fluid heat storage material; The cooling device of claim 2, wherein the mechanism includes a cooler (1721) filled with the fluid medium and thermally connected to the battery, a pump (1722) for controlling the flow of the fluid medium, and piping (1723) connecting the cooler and the pump.

13. The cooling device according to claim 2 or claim 12, further comprising a fitting (18) for connecting the fluid heat storage material and / or a fluid medium which is a mixed heat storage material obtained by mixing the latent heat storage material and the fluid heat storage material to an off-board cooling device on the ground.

14. an on-board cooling device (17) mounted on the electric flying object (10) and configured to cool a battery (14) of the electric flying object using one or more types of heat storage materials (171); an external cooling device (40) for cooling the battery on the ground; Equipped with The heat storage material includes, as a latent heat storage material (1711), a first latent heat storage material (1711A) whose phase transition temperature is set so as to absorb heat generated by the battery during takeoff and heat generated by the battery during landing, and / or a second latent heat storage material (1711B) whose phase transition temperature is set so as to absorb heat generated by the battery during landing, The external cooling device is a cooling system that cools the heat storage material and the battery by flowing a fluid medium.

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