Heating systems for work machines, cabs, and methods for heating cabs

Abstract

This invention provides a work machine that can efficiently heat the inside of the cab by utilizing a heater core installed in the cab. [Solution] The work machine comprises fuel cell related components, a heater core installed in the cab, an electric heater, and piping having an electromagnetic switching valve and through which liquid flows. The piping is selectively configured as a first circulation path and a second circulation path by switching the electromagnetic switching valve. The first circulation path is configured so that the liquid circulates only through the electric heater and fuel cell related components, and through the heater core. The second circulation path is configured so that the liquid circulates only through the fuel cell related components and through the heater core.

Description

Technical Field

[0001] The present disclosure relates to a work machine, a cab heating system, and a cab heating method.

Background Art

[0002] Conventionally, work machines equipped with fuel cells are known. For example, Japanese Patent Application Laid-Open No. 2014-065376 (Patent Document 1) discloses a forklift in which a fuel cell system having a fuel cell is disposed in a storage chamber adjacent to a driver's cab (hereinafter referred to as a cab).

[0003] In this forklift, the storage chamber is disposed under the floor of the cab. Further, a supply flow path is formed in the forklift to guide the heat radiation air of a radiator that cools the coolant of the fuel cell to the cab. An air outlet for blowing out the heat radiation air flowing through the supply flow path into the cab is provided in the floor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] There is a demand for efficiently heating the interior of a cab by using a heater core provided in the cab. The present disclosure provides a work machine, a cab heating system, and a cab heating method capable of efficiently heating the interior of a cab by using a heater core provided in the cab.

Means for Solving the Problems

[0006] In accordance with a certain aspect of this disclosure, the working machine comprises fuel cell-related components, a heater core installed in a cab, an electric heater, and piping having an electromagnetic switching valve and through which liquid flows. The piping is selectively configured as a first circulation path and a second circulation path by switching the electromagnetic switching valve. The first circulation path is configured such that the liquid circulates only through the electric heater and the fuel cell-related components, and through the heater core. The second circulation path is configured such that the liquid circulates only through the fuel cell-related components and through the heater core. [Effects of the Invention]

[0007] With this configuration, it becomes possible to efficiently heat the inside of the cab using the heater core installed in the cab. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view illustrating the general structure of the shovel. [Figure 2] This is a diagram illustrating the internal structure of the rotating body. [Figure 3] This is a diagram illustrating the surrounding structure of the heater core. [Figure 4] This is a diagram illustrating the circulation path of liquid within a pipe. [Figure 5] This is a diagram illustrating other circulation paths for liquid within a pipe. [Figure 6] This is a flowchart illustrating the process of warming the inside of the cab. [Figure 7] This is a diagram showing the heating system in the cab. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described below with reference to the drawings. In the specification and drawings, the same or corresponding components are denoted by the same reference numerals, and redundant descriptions are avoided. Also, in the drawings, some components may be omitted or simplified for the sake of clarity.

[0010] In the following explanation, "up," "down," "front," "rear," "left," and "right" refer to directions relative to the operator seated in the cab (driver's compartment). Therefore, the front-rear direction refers to the direction in which the boom 16 extends between its base and tip when viewed from above. The left-right direction refers to the direction perpendicular to the front-rear direction when viewed from above. The up-down direction refers to the direction perpendicular to the plane that includes the mutually perpendicular front-rear and left-right directions.

[0011] The work machine described herein is a fuel cell vehicle (FCV). In the following description, an excavator will be used as an example of such a fuel cell vehicle. However, the fuel cell vehicle is not limited to an excavator and may also be a bulldozer, wheel loader, motor grader, forklift, etc.

[0012] <Overall structure of an excavator> Figure 1 is a schematic side view showing the configuration of a shovel in one embodiment of the present disclosure.

[0013] As shown in Figure 1, the shovel 1 comprises a main body 11 and a hydraulically operated work implement 12. The main body 11 includes a slewing body 13 and a traveling body 15.

[0014] The vehicle 15 has a pair of left and right tracks 15Cr and a drive motor 15M. The shovel 1 can move by the rotation of the tracks 15Cr. The drive motor 15M is provided as the drive source for the vehicle 15. The drive motor 15M may be a hydraulic motor or an electric motor.

[0015] The revolving body 13 is disposed on the traveling body 15 and supported by the traveling body 15. The revolving body 13 is rotatable with respect to the traveling body 15 about a rotation axis RX by a rotation motor (not shown). The rotation axis RX is an imaginary straight line that serves as the center of rotation of the revolving body 13. The rotation motor may be a hydraulic motor or an electric motor.

[0016] The revolving body 13 has a cab 14. Inside the cab 14, a driver's seat 14S on which an operator sits is provided. The operator can sit on the driver's seat 14S and operate the work implement 12, rotate the revolving body 13 with respect to the traveling body 15, and operate the traveling of the excavator 1 by the traveling body 15.

[0017] The work implement 12 is supported by the revolving body 13. The work implement 12 has a boom 16, an arm 17, and a bucket 18. The work implement 12 further has a boom cylinder 19a, an arm cylinder 19b, and a bucket cylinder 19c. Each of the cylinders 19a, 19b, 19c may be a hydraulic cylinder or may be driven by an electric motor.

[0018] The boom 16 is rotatably connected to the main body 11. Specifically, the base end portion of the boom 16 is rotatably connected to the revolving body 13 with a boom foot pin BF as a fulcrum. The base end portion of the boom 16 is disposed in the left-right direction of the cab 14. The arm 17 is rotatably connected to the boom 16. Specifically, the base end portion of the arm 17 is rotatably connected to the tip end portion of the boom 16 with a boom top pin BT as a fulcrum. The bucket 18 is rotatably connected to the arm 17. Specifically, the base end portion of the bucket 18 is rotatably connected to the tip end portion of the arm 17 with an arm top pin AT as a fulcrum.

[0019] The revolving body 13 further has an exterior panel OP surrounding the machine room, a hydrogen tank 21, and a fuel cell module 30. Inside the machine room of the revolving body 13, the hydrogen tank 21, the fuel cell module 30, etc. are disposed. The surroundings of the hydrogen tank 21, the fuel cell module 30, etc. are covered by the exterior panel OP.

[0020] The fuel cell module 30 includes a fuel cell stack 31, auxiliary equipment 32 for the fuel cell stack 31, a cooling circuit (not shown) for cooling the fuel cell stack 31, and a cooling circuit (Figure 2) for cooling the auxiliary equipment 32. The fuel cell stack 31 and the auxiliary equipment 32 are cooled by different cooling circuits. The type of liquid (refrigerant) for cooling the fuel cell stack 31 is different from the type of liquid (refrigerant) for cooling the auxiliary equipment 32. Details of the cooling circuit for the auxiliary equipment 32 will be described later.

[0021] The hydrogen tank 21 supplies hydrogen to the fuel cell stack 31. The excavator 1 has, for example, two hydrogen tanks 21, but the number of hydrogen tanks 21 mounted on the excavator 1 is not limited to two.

[0022] The fuel cell stack 31 is formed by connecting and stacking a plurality of fuel cells in series. The fuel cell stack 31 generates electricity (electrical energy) by chemically reacting hydrogen and oxygen. The generated electrical energy drives a hydraulic pump (not shown) via an electric motor. The hydraulic oil discharged from the hydraulic pump by driving the hydraulic pump actuates each hydraulic actuator (swing motor, travel motor, each hydraulic cylinder).

[0023] When an electric motor is used instead of each hydraulic actuator, the generated electrical energy is directly supplied to each electric motor. In this example, the excavator 1 has one fuel cell stack 31, but the number of fuel cell stacks 31 mounted on the excavator 1 is not limited to one and may be plural.

[0024] The auxiliary equipment 32 operates the fuel cell stack 31 as the main unit. The auxiliary equipment 32 includes a compressor, piping, a controller, a DC-DC converter, etc. (not shown). The compressor supplies air to the fuel cell stack 31. The controller controls the compressor and communicates with external devices of the fuel cell module 30. The auxiliary equipment 32 generates heat when operating the fuel cell stack 31. For example, the compressor, controller, etc. generate heat. Note that the auxiliary equipment 32 is an example of the "fuel cell related components" in this disclosure.

[0025] <Internal structure> Figure 2 is a diagram illustrating the internal structure of the rotating body 13.

[0026] As shown in Figure 2, the slewing body 13, in addition to the cab 14 and auxiliary equipment 32, further comprises piping 100, an electric heater 210, a radiator 220, pumps 230 and 240, a temperature sensor 250, a controller 310, a switch 320, and a heater core 603. The heater core 603 is installed inside the cab 14. The electric heater 210 has a heating element 211.

[0027] The piping 100 includes a first piping section 110, a second piping section 120, a third piping section 130, a fourth piping section 140, and solenoid valves 150 and 160. The first piping section 110, the second piping section 120, the third piping section 130, and the fourth piping section 140 are connected to the solenoid valves 150 and 160. The piping 100 is filled with liquid (refrigerant). Pumps 230 and 240 circulate the liquid within the piping 100.

[0028] The solenoid valves 150 and 160 are four-way control valves. The solenoid valve 150 has ports 151 to 154. The solenoid valve 160 has ports 161 to 164. The solenoid valves 150 and 160 are connected to the radiator 220 via piping 100. A heater core 603 is positioned between the solenoid valves 150 and 160.

[0029] The first piping section 110 is positioned between the solenoid valve 150 and the solenoid valve 160, with the heater core 603 in between. The first piping section 110 is connected to port 154 of the solenoid valve 150 and port 162 of the solenoid valve 160.

[0030] The second piping section 120 has the heating element 211 of the electric heater 210 located inside and is positioned between the electromagnetic switching valve 150 and the electromagnetic switching valve 160. The second piping section 120 is connected to the port 151 of the electromagnetic switching valve 150 and the port 161 of the electromagnetic switching valve 160.

[0031] The third piping section 130 is positioned between the solenoid valve 150 and the solenoid valve 160, with the radiator 220 in between, and is in direct contact with the auxiliary equipment 32 or via a heat conductive material (not shown). The third piping section 130 is connected to port 153 of the solenoid valve 150 and port 163 of the solenoid valve 160.

[0032] The fourth piping section 140 is a bypass piping section. The fourth piping section 140 is connected to port 152 of the solenoid valve 150 and port 164 of the solenoid valve 160.

[0033] Pump 230 is installed in the second piping section 120. Pump 230 is installed in the second piping section 120 between the heating element 211 and the solenoid valve 150. Pump 230 pumps liquid in the second piping section 120 toward the solenoid valve 150. The operation of pump 230 is controlled by controller 310.

[0034] Pump 240 is installed in the third piping section 130. Pump 240 is installed in the third piping section 130 between the radiator 220 and the solenoid valve 150. Pump 240 is installed in the third piping section 130 between the radiator 220 and the auxiliary equipment 32. Pump 240 pumps liquid in the third piping section 130 toward the solenoid valve 150. The operation of pump 240 is controlled by controller 310 or another controller (not shown).

[0035] The radiator 220 is installed in the third piping section 130 between the solenoid valve 160 and the pump 240. Liquid flows inside the radiator 220. As a result, the radiator 220 cools the liquid flowing through the third piping section 130.

[0036] Auxiliary unit 32 is installed between the radiator 220 and the solenoid valve 150. Auxiliary unit 32 is in contact with the area between the radiator 220 and the solenoid valve 150 in the third piping section 130. Auxiliary unit 32 is installed between the pump 240 and the solenoid valve 150. Auxiliary unit 32 is in contact with the area between the pump 240 and the solenoid valve 150 in the third piping section 130. Auxiliary unit 32 is cooled by the liquid flowing through the third piping section 130. Auxiliary unit 32 is cooled by heat exchange with the liquid cooled by the radiator 220.

[0037] In this example, the temperature sensor 250 is installed in the third piping section 130. The temperature sensor 250 is installed in the third piping section 130 between the auxiliary equipment 32 and the solenoid valve 150. The temperature sensor 250 comes into contact with the liquid flowing through the third piping section 130 and detects the temperature of the liquid. The temperature sensor 250 measures the temperature of the liquid heated by heat exchange with the auxiliary equipment 32. The temperature sensor 250 sends the detection result to the controller 310.

[0038] The controller 310 includes a processor, main memory, and storage. The processor is, for example, a CPU (Central Processing Unit). The main memory includes non-volatile memory such as ROM (Read Only Memory) and volatile memory such as RAM (Random Access Memory).

[0039] The controller 310 is electrically connected to the temperature sensor 250, the switch 320, and the solenoid valves 150 and 160. The controller 310 receives the temperature detected by the temperature sensor 250 as input. The controller 310 switches the solenoid valves 150 and 160. The controller 310 sends a command (signal) to the solenoid valves 150 and 160 to switch the flow path of the liquid.

[0040] When the temperature detected by the temperature sensor 250 exceeds a predetermined temperature (hereinafter also referred to as the "threshold"), the controller 310 outputs a command to the electromagnetic switching valves 150 and 160. The command continues to be output until the temperature detected by the temperature sensor 250 falls below the threshold. In this example, the command is a signal (current) of a predetermined voltage. In this example, the threshold is a constant temperature between 55°C and 60°C (for example, 60°C).

[0041] In this example, when the controller 310 is not outputting commands to the electromagnetic switching valve 150, ports 151 and 154 of the electromagnetic switching valve 150 are in communication, and ports 152 and 153 are in communication. When the controller 310 is continuously outputting commands to the electromagnetic switching valve 150, ports 151 and 152 of the electromagnetic switching valve 150 are in communication, and ports 153 and 154 are in communication.

[0042] Similarly, when the controller 310 is not outputting commands to the electromagnetic switching valve 160, ports 161 and 162 of the electromagnetic switching valve 160 are in communication, and ports 163 and 164 are in communication. When the controller 310 is continuously outputting commands to the electromagnetic switching valve 160, ports 161 and 164 of the electromagnetic switching valve 160 are in communication, and ports 162 and 163 are in communication.

[0043] Switch 320 is an operating switch for turning the air conditioner on and off. When the operator turns on switch 320, an on signal is input from switch 320 to controller 310. When the operator turns off switch 320, the signal input to controller 310 stops.

[0044] Figure 3 is a diagram illustrating the surrounding structure of the heater core 603. As shown in Figure 3, the cab 14 comprises a housing 400 through which air flows. The housing 400 includes dampers 411-415 for air conditioning and a chamber 420. The housing 400 has an air intake 491, air conditioner air outlets 492, 493 and a defroster outlet 494. The air outlets 492 are located around the instrument panel. The air outlets 492 include a left air outlet 492L, a central air outlet 492C, and a left air outlet 492R. The air outlets 493 are located at the operator's feet.

[0045] The slewing body 13 further comprises motors 511 to 513. Motor 511 drives damper 411. Motor 512 drives damper 412. Motor 513 drives dampers 413 to 415. Motors 511 to 513 are controlled by controller 310 or other controllers (not shown).

[0046] Inside the enclosure 400 are a blower fan 601, an evaporator 602, and a heater core 603. A pipe 620 that supplies refrigerant to the evaporator 602 is connected to the evaporator 602. As mentioned above, the first piping section 110 is connected to the heater core 603. As mentioned above, the first piping section 110 is connected to solenoid valves 150 and 160.

[0047] The damper 411 controls whether indoor air or outdoor air is drawn into the housing 400. The blower fan 601 draws air into the housing 400 from the intake port 491, as shown by arrow 901. The drawn-in air is sent to the evaporator 602, as shown by arrow 902. The air is cooled as it passes through the gaps in the evaporator 602.

[0048] The damper 412 controls the airflow that has passed through the evaporator 602. The damper 412 has the function of mixing cold air and warm air. When the damper 412 is in the position shown in Figure 3, as indicated by arrow 903, all the air that has passed through the evaporator 602 is heated by passing through the gap in the heater core 603.

[0049] When the damper 412 rotates clockwise around the pivot center 412c from the state shown in Figure 3, some or all of the air is sent to the chamber 420 without passing through the heater core 603, depending on the rotation angle. As a result, the warm air that has passed through the heater core 603 and the cold air that has not passed through the heater core 603 are mixed in the chamber 420. The temperature of the air conditioner is adjusted by this air mix.

[0050] In Figure 3, dampers 413 and 414 are in the closed position, and damper 415 is in the open position. As a result, the air heated by the heater core 603 is blown out towards the operator's feet through the chamber 420 and the air outlet 493, as shown by arrow 904.

[0051] When damper 414 is closed and dampers 413 and 415 are open, the air heated by the heater core 603 is blown out through the chamber 420 and air outlets 492 and 493 towards the operator's upper body and feet. In this way, the inside of the cab 14 (especially the operator's space) is heated.

[0052] In the following description, we assume that damper 412 is in the state shown in Figure 3, and damper 414 is in the closed state. Furthermore, we assume that at least one of dampers 413 and 415 is in the open state.

[0053] <Circulation channel> Figures 4 and 5 are diagrams illustrating the circulation path of the liquid within the piping 100. Specifically, Figure 4 is a diagram illustrating the circulation path in a state where the controller 310 is not outputting the aforementioned commands to the solenoid valves 150 and 160 (hereinafter also referred to as the "command stop state"). Figure 5 is a diagram illustrating the circulation path in a state where the controller 310 is continuously outputting the aforementioned commands to the solenoid valves 150 and 160 (hereinafter also referred to as the "command output state").

[0054] As shown in Figure 4, in the command stop state, circulation path R1 and circulation path R3 are configured. Specifically, when the temperature detected by the temperature sensor 250 is below the threshold, circulation path R1 and circulation path R3 are configured in the piping 100. Circulation path R1 is composed of the first piping section 110 and the second piping section 120. Circulation path R3 is composed of the third piping section 130 and the bypass fourth piping section 140.

[0055] For example, immediately after the auxiliary equipment 32 starts up, the heat dissipated by the auxiliary equipment 32 is small, so the temperature of the liquid in the third piping section 130 does not reach the threshold. In such a situation, the piping 100 is configured with a circulation path R1 and a circulation path R3 as described above.

[0056] In the command-stop state, pumps 230 and 240 operate. Therefore, the liquid in piping 100 circulates through circulation path R1 and circulation path R3. More specifically, a portion of the liquid circulates through circulation path R1, and the remainder circulates through circulation path R3.

[0057] The circulation channel R1 is configured such that the liquid circulates only through the electric heater 210 and the heater core 603, among the electric heater 210 and the auxiliary equipment 32. In the circulation channel R1, the liquid is heated by the electric heater 210, and the liquid heated by the electric heater 210 circulates only through the electromagnetic switching valves 150, 160 and the heater core 603, among the electromagnetic switching valves 150, 160, the heater core 603 and the radiator 220. Thus, in the circulation channel R1, the liquid does not pass through the radiator 220. More specifically, in the circulation channel R1, the liquid heated by the electric heater 210 flows through the pump 230, port 151, port 154, heater core 603, port 162, and port 161 in that order.

[0058] In the circulation path R3, the liquid cooled by the radiator 220 flows through the pump 240, port 153, port 152, port 164, and port 163 in that order. In the circulation path R3, the liquid cooled by the radiator 220 is used to cool the auxiliary equipment 32. The liquid, heated by heat exchange with the auxiliary equipment 32, is returned to the radiator 220 without passing through the heater core 603. The circulation path R3 corresponds to the cooling circuit that cools the auxiliary equipment 32.

[0059] As shown in Figure 5, in the command output state, the circulation path R2 is configured. In the command output state, the circulation path R2 is configured instead of the circulation paths R1 and R3. Specifically, when the temperature detected by the temperature sensor 250 is above a threshold, the circulation path R2 is configured in the piping 100. The circulation path R2 is composed of the first piping section 110 and the third piping section 130.

[0060] More specifically, once sufficient time has elapsed since the auxiliary equipment 32 started, the amount of heat generated by the auxiliary equipment 32 increases, causing the temperature of the liquid in the third piping section 130 to reach a threshold. In this situation, a circulation path R2 is formed in the piping 100 as described above. Furthermore, once the circulation path R2 is formed, the controller 310 turns off the electric heater 210.

[0061] In the command output state, only pump 240 operates out of pumps 230 and 240. In the command output state, the controller 310 stops the operation of pump 230. Therefore, the liquid in piping 100 circulates only through the circulation path R2.

[0062] The circulation channel R2 is configured such that the liquid circulates only through the auxiliary equipment 32 of the electric heater 210 and through the heater core 603. In the circulation channel R2, the liquid is heated by heat exchange with the auxiliary equipment 32, and the liquid heated by this heat exchange circulates through the electromagnetic switching valve 150, the heater core 603, the electromagnetic switching valve 160, and the radiator 220. In the circulation channel R2, the liquid heated by heat exchange circulates in the following order: port 153, port 154, heater core 603, port 162, port 163, radiator 220, and pump 240. In the circulation channel R2, as in the circulation channel R3, the liquid cooled by the radiator 220 is used to cool the auxiliary equipment 32. Note that the circulation channel R2, like the circulation channel R3, corresponds to a cooling circuit that cools the auxiliary equipment 32.

[0063] In the command output state, a flow path is formed by the second piping section 120 and the bypass fourth piping section 140. However, in the command output state, the controller 310 stops the pump 230, so no liquid circulates in this flow path.

[0064] <Control Structure> Figure 6 is a flowchart illustrating the process of warming the inside of the cab 14.

[0065] As shown in Figure 6, when switch 320 is pressed, in step S1, controller 310 activates electric heater 210. At this point, the piping 100 consists of circulation path R1 and circulation path R3 as shown in Figure 4.

[0066] In step S2, the controller 310 determines whether the temperature detected by the temperature sensor 250 is above a threshold. If the detected temperature is above the threshold (YES in step S2), in step S3, the controller 310 outputs the above-mentioned command to each of the electromagnetic switching valves 150 and 160. As a result, in the piping 100, the circulation path R2 shown in Figure 5 is configured instead of the circulation paths R1 and R3. If the detected temperature is below the threshold (NO in step S2), the controller 310 proceeds to step S8. In step S4, the controller 310 turns off the electric heater 210.

[0067] In step S5, the controller 310 determines whether the temperature detected by the temperature sensor 250 is below a threshold. If the detected temperature is below the threshold (YES in step S5), in step S6, the controller 310 operates the electric heater 210. In step S7, the controller 310 stops outputting the command described above. As a result, in the piping 100, the circulation paths R1 and R3 shown in Figure 4 are reconfigured instead of the circulation path R2. If the detected temperature is not below the threshold (NO in step S5), the controller 310 proceeds to step S9.

[0068] In step S8, the controller 310 determines whether the switch 320 has received an operation to stop the air conditioner. If it is determined that the operation to stop the air conditioner has been received (YES in step S8), the controller 310 terminates the series of processes. If it is determined that the operation to stop the air conditioner has not been received (NO in step S8), the controller 310 proceeds to step S2.

[0069] In step S9, similar to step S8, the controller 310 determines whether the switch 320 has received an operation to stop the air conditioner. If it is determined that the operation to stop the air conditioner has been received (YES in step S9), the controller 310 stops outputting the command described above. As a result, in the piping 100, the circulation paths R1 and R3 shown in Figure 4 are reconfigured instead of the circulation path R2. This completes the series of processes. If it is determined that the operation to stop the air conditioner has not been received (NO in step S9), the controller 310 proceeds to step S5.

[0070] <Summary> In summary, Shovel 1 can be described as follows:

[0071] (1) The excavator 1 comprises an auxiliary machine 32, a heater core 603 installed inside the cab 14, an electric heater 210, and a pipe 100 through which liquid flows, having electromagnetic switching valves 150 and 160. The pipe 100 is selectively configured as a circulation path R1 (Figure 4) and a circulation path R2 (Figure 5) by switching the electromagnetic switching valves 150 and 160. The circulation path R1 is configured so that the liquid circulates only through the electric heater 210 of the electric heater 210 and the auxiliary machine 32, and through the heater core 603. The circulation path R2 is configured so that the liquid circulates only through the auxiliary machine 32 of the electric heater 210 and the auxiliary machine 32, and through the heater core 603.

[0072] With this configuration, by configuring the circulation path R1 with the electromagnetic switching valves 150 and 160, the liquid via the electric heater 210 can be sent to the heater core 603. This allows the inside of the cab 14 to be heated. Furthermore, by configuring the circulation path R2 with the electromagnetic switching valves 150 and 160, the liquid via the auxiliary equipment 32 can be sent to the heater core 603. This also allows the inside of the cab 14 to be heated.

[0073] Thus, in the Shovel 1, liquid can be selectively supplied to the heater core 603 via the electric heater 210 and liquid via the auxiliary device 32. Therefore, compared to a configuration in which only liquid supplied to the heater core 603 via the electric heater 210, or a configuration in which only liquid supplied to the heater core 603 via the auxiliary device 32, it is possible to efficiently heat the inside of the cab 14 (more specifically, the air inside the cab 14). In this way, the Shovel 1 makes it possible to efficiently heat the inside of the cab 14 by utilizing the heater core 603 provided in the cab 14.

[0074] (2) In circulation channel R1, the liquid is heated by the electric heater 210, and in circulation channel R2, the liquid is heated by heat exchange with the auxiliary equipment 32. With this configuration, in circulation channel R1, the liquid heated by the electric heater 210 can be sent to the heater core 603. This allows the inside of the cab 14 to be heated. In circulation channel R2, the liquid heated by the waste heat of the auxiliary equipment 32 can be sent to the heater core 603.

[0075] (3) The shovel 1 further comprises a radiator 220 connected to the piping 100. The circulation path R1 is configured such that the liquid heated by the electric heater 210 circulates only through the electromagnetic switching valves 150, 160 and the heater core 603 among the electromagnetic switching valves 150, 160 and the heater core 603 and the radiator 220. The circulation path R2 is configured such that the liquid heated by heat exchange circulates through the electromagnetic switching valves 150, 160, the heater core 603 and the radiator 220.

[0076] With this configuration, the liquid heated by the waste heat from the auxiliary equipment 32 can be cooled by the radiator. Therefore, it is possible to continue cooling the auxiliary equipment 32 in the circulation path R2.

[0077] (4) The shovel 1 is further equipped with a temperature sensor 250 for measuring the temperature of the liquid heated by heat exchange with the auxiliary equipment 32. The heater core 603 is located between the solenoid valve 150 and the solenoid valve 160. The controller 310 switches the solenoid valves 150 and 160 so that a circulation path R1 (Figure 4) is configured when the temperature of the liquid heated by heat exchange is below a threshold. The controller 310 switches the solenoid valves 150 and 160 so that a circulation path R2 (Figure 5) is configured when the temperature of the liquid heated by heat exchange is above a threshold.

[0078] With this configuration, if the heat discharged by the auxiliary equipment 32 is large, the temperature of the liquid heated by heat exchange with the auxiliary equipment 32 will exceed a threshold, making it possible to use the heat discharged by the auxiliary equipment 32 to warm the inside of the cab 14. Therefore, electricity consumption can be reduced compared to a configuration that uses only the electric heater 210 to warm the inside of the cab 14. In particular, since the shovel 1 is a fuel cell vehicle, the driving range can be extended compared to a configuration that uses only the electric heater 210 to warm the inside of the cab 14.

[0079] On the other hand, when the heat generated by the auxiliary engine 32 is small, such as when starting the shovel 1, the electric heater 210 can be used to warm the inside of the cab 14. Therefore, the shovel 1 offers superior rapid heating compared to a configuration that uses only the heat generated by the auxiliary engine 32 to warm the inside of the cab 14.

[0080] (5) The controller 310 turns off the electric heater 210 if the temperature of the liquid heated by heat exchange with the auxiliary equipment 32 is above a threshold.

[0081] With this configuration, electricity consumption can be reduced compared to a configuration in which the electric heater 210 is kept on when the temperature of the liquid heated by heat exchange with the auxiliary device 32 is above a threshold.

[0082] (6) The piping 100 includes a first piping section 110, a second piping section 120, and a third piping section 130, each connected to the solenoid valves 150 and 160. The first piping section 110 is located between the solenoid valves 150 and 160, with the heater core 603 in between. The second piping section 120 has the heating element 211 of the electric heater 210 located inside and is located between the solenoid valves 150 and 160. The third piping section 130 is located between the solenoid valves 150 and 160, with the radiator 220 in between, and is in direct contact with the auxiliary equipment 32 or in contact with a heat conductive material.

[0083] The circulation channel R1 (Figure 4) is composed of the first piping section 110 and the second piping section 120. The circulation channel R2 (Figure 5) is composed of the first piping section 110 and the third piping section 130.

[0084] With this configuration, circulation path R1 and circulation path R2 share a portion of the first piping section. Therefore, the heater core 603 can be selectively supplied with liquid heated by the electric heater 210 and liquid heated by heat exchange with the auxiliary equipment 32.

[0085] (7) The solenoid valves 150 and 160 are four-way solenoid valves. The piping 100 further includes a fourth bypass piping section 140 connected to the solenoid valves 150 and 160. When the circulation path R1 (Figure 4) is configured, the third piping section 130 and the fourth piping section 140 form a circulation path R3 (Figure 4) through which the liquid heated by heat exchange with the auxiliary equipment 32 circulates.

[0086] With this configuration, even if the circulation channel R1 is configured, the auxiliary equipment 32 can continue to be cooled by the circulation channel R3.

[0087] (8) The liquid heated by heat exchange with the auxiliary unit 32 circulates through the solenoid valve 150, the heater core 603, the solenoid valve 160, and the radiator 220 in that order. The auxiliary unit 32 is installed between the radiator 220 and the solenoid valve 150. The temperature sensor 250 is installed between the auxiliary unit 32 and the solenoid valve 150.

[0088] With this configuration, the temperature sensor 250 can measure the temperature of the liquid that has been heated by heat exchange with the auxiliary equipment 32 after passing through the radiator 220, and before passing through the electromagnetic switching valve 150. The liquid that has passed through the electromagnetic switching valve 150 is supplied to the heater core 603 before passing through the radiator 220.

[0089] In this way, the temperature sensor 250 can measure a temperature close to the temperature of the liquid when it is supplied to the heater core 603. Therefore, compared to measuring the temperature of the liquid immediately after it has passed through the radiator 220, or after it has passed through the heater core 603 but before it is supplied to the radiator 220, the controller 310 can accurately determine the temperature of the liquid supplied to the heater core 603.

[0090] <Variation> (1) In the above description, the example given was that circulation paths R1 and R3 are configured when the controller 310 does not output commands to the solenoid valves 150 and 160, and circulation path R2 is configured when the controller 310 continues to output commands. However, the configuration is not limited to the selection of circulation paths R1 and R3 and circulation path R2 depending on whether or not a command is output. For example, the shovel 1 may be configured such that when the controller 310 outputs a first command to the solenoid valves 150 and 160, circulation paths R1 and R3 are configured, and when the controller 310 outputs a second command to the solenoid valves 150 and 160, circulation path R2 is configured instead of circulation paths R1 and R3.

[0091] (2) In the circulation channel R2, the liquid is heated by heat exchange with the auxiliary equipment 32, but is not limited to this. The circulation channel R2 may be configured so that the liquid is heated by heat exchange with the fuel cell stack 31. With such a configuration, it is possible to efficiently heat the inside of the cab 14 using the heater core 603 provided in the cab 14. In this case, the fuel cell stack 31 is an example of the "fuel cell related component" in this disclosure.

[0092] Furthermore, the circulation path R2 may be configured such that the cooling path for the auxiliary equipment 32 and the cooling path for the fuel cell stack 31 are the same. In this case, the liquid in the circulation path R2 is heated by heat exchange with the auxiliary equipment 32 and with the fuel cell stack 31. With this configuration as well, it is possible to efficiently heat the inside of the cab 14 using the heater core 603 provided in the cab 14.

[0093] (3) Excavator 1, separate from the fuel cell stack 31 and auxiliary equipment 32, has a DC-DC converter, an inverter, the aforementioned electric motor, a battery thermal management system, etc. These four electrical components are included in the power source of Excavator 1. The current output from the DC-DC converter is supplied to the electric motor via the inverter. The DC-DC converter, inverter, electric motor, and battery thermal management system are connected in series. The battery thermal management system manages the temperature of an auxiliary power source (for example, a lithium battery) that is different from the fuel cell stack 31. The battery thermal management system cools or heats the auxiliary power source so that its temperature remains constant.

[0094] The circulation channel R2 may be configured such that the liquid is heated by heat exchange with at least one of the four electrical components described above. With such a configuration, it is possible to efficiently heat the inside of the cab 14 using the heater core 603 provided in the cab 14. In this case, the electrical components described above are examples of "fuel cell related components" as disclosed herein.

[0095] (4) In the above description, an example was given in which a controller 310 (Figure 2, etc.) inside the shovel 1 transmits a command (signal) to the electromagnetic switching valves 150 and 160 to switch the flow path of the liquid. However, the description is not limited to this.

[0096] Figure 7 shows the heating system of cab 14. As shown in Figure 7, the heating system 1000 includes the shovel 1 and an external controller 700. The external controller 700 is a remote control device. The external controller 700 includes a processor, main memory, storage, display, communication interface, etc.

[0097] In such a system configuration, a communication interface may be provided within the excavator 1 instead of the controller 310, and the external controller 700 may transmit commands to the electromagnetic switching valves 150 and 160 to switch the flow path of the liquid via the communication interface.

[0098] In this case, the external controller 700 acquires temperature information detected by the temperature sensor 250 via the communication interface. Furthermore, it is preferable to provide the external controller 700 with functions similar to those of the switch 320. For example, it is preferable to configure the external controller 700 so that its processor displays an object (selectable image) on the external controller 700's display that performs the same functions as the switch 320.

[0099] Even with this system configuration, it is possible to efficiently heat the inside of the cab 14 by utilizing the heater core 603 provided in the cab 14.

[0100] <Note> [Configuration 1] Fuel cell related parts, The heater core installed inside the cab, Electric heater and, It comprises a solenoid valve and piping through which liquid flows, The aforementioned piping is configured to selectively consist of a first circulation path and a second circulation path by switching the solenoid valve. The first circulation channel is configured such that the liquid circulates only through the electric heater among the electric heater and the fuel cell related components, and through the heater core. A working machine wherein the second circulation channel is configured to circulate the liquid only through the fuel cell-related components among the electric heater and the fuel cell-related components, and through the heater core. [Configuration 2] In the first circulation channel, the liquid is heated by the electric heater. In the second circulation channel, the liquid is heated by heat exchange with the fuel cell-related components, as described in Configuration 1 of the working machine. [Configuration 3] The system further includes a radiator connected to the aforementioned piping, The first circulation path is configured such that the liquid heated by the electric heater circulates only through the electromagnetic switching valve and the heater core among the electromagnetic switching valve, the heater core and the radiator. The working machine according to configuration 2, wherein the second circulation channel is configured such that the liquid heated by the heat exchange circulates through the electromagnetic switching valve, the heater core, and the radiator. [Structure 4] The system further includes a controller for switching the aforementioned electromagnetic switching valve, The system further includes a sensor for measuring the temperature of the liquid heated by the aforementioned heat exchange, The solenoid switching valve includes a first and a second solenoid switching valve, The heater core is positioned between the first electromagnetic switching valve and the second electromagnetic switching valve. The aforementioned controller, If the temperature of the liquid heated by the heat exchange is below a predetermined temperature, the first and second solenoid valves are switched so that the first circulation path is configured. The working machine according to configuration 3, wherein the first and second electromagnetic switching valves are switched so that the second circulation path is configured when the temperature of the liquid heated by the heat exchange is equal to or greater than the predetermined temperature. [Composition 5] The working machine according to configuration 4, wherein the controller turns off the electric heater when the temperature of the liquid heated by the heat exchange is above a predetermined temperature. [Composition 6] The piping includes first to third piping sections, each connected to the first and second solenoid valves, The first piping section is positioned between the first electromagnetic switching valve and the second electromagnetic switching valve, with the heater core in between. The second piping section has the heating element of the electric heater located inside and is positioned between the first electromagnetic switching valve and the second electromagnetic switching valve. The third piping section is positioned between the first and second solenoid valves, with the radiator in between, and is in direct contact with the fuel cell-related components or in contact with a heat conductive material. The first circulation channel is composed of the first piping section and the second piping section, The working machine according to configuration 4 or 5, wherein the second circulation channel is composed of the first piping section and the third piping section. [Composition 7] The first and second electromagnetic switching valves are four-way electromagnetic switching valves. The piping further includes a fourth bypass piping section connected to the first and second solenoid valves, The working machine according to configuration 6, wherein when the first circulation channel is configured, the third piping section and the fourth piping section constitute a third circulation channel through which the liquid heated by the heat exchange circulates. [Structure 8] The liquid heated by the heat exchange circulates through the first electromagnetic switching valve, the heater core, the second electromagnetic switching valve, and the radiator in that order. The fuel cell-related components are installed between the radiator and the first electromagnetic switching valve. The working machine according to configuration 6 or 7, wherein the sensor is installed between the fuel cell-related component and the first electromagnetic switching valve. [Composition 9] The aforementioned predetermined temperature is a constant temperature of 55°C or higher and 60°C or lower, as described in configuration 4 of the work machine. [Configuration 10] Equipped with an additional fuel cell stack, The fuel cell-related component is an auxiliary machine for the fuel cell stack, as described in any one of items 1 to 9. [Composition 11] Fuel cell related parts, The heater core installed inside the cab of the work machine, Electric heater and, It comprises a solenoid valve and piping through which liquid flows, The aforementioned piping is configured to selectively consist of a first circulation path and a second circulation path by switching the solenoid valve. The first circulation channel is configured such that the liquid circulates only through the electric heater among the electric heater and the fuel cell related components, and through the heater core. A heating system for a cab, wherein the second circulation channel is configured to circulate the liquid only through the fuel cell-related components among the electric heater and the fuel cell-related components, and through the heater core. [Composition 12] The system further includes a radiator connected to the aforementioned piping, In the first circulation channel, the liquid is heated by the electric heater. In the second circulation channel, the liquid is heated by heat exchange with the fuel cell-related components. The first circulation path is configured such that the liquid heated by the electric heater circulates only through the electromagnetic switching valve and the heater core among the electromagnetic switching valve, the heater core and the radiator. The cab heating system according to configuration 11, wherein the second circulation path is configured such that the liquid heated by the heat exchange circulates through the electromagnetic switching valve, the heater core, and the radiator. [Composition 13] The system further includes a controller for switching the aforementioned electromagnetic switching valve, The system further includes a sensor for measuring the temperature of the liquid heated by the aforementioned heat exchange, The solenoid switching valve includes a first and a second solenoid switching valve, The heater core is positioned between the first electromagnetic switching valve and the second electromagnetic switching valve. The aforementioned controller, If the temperature of the liquid heated by the heat exchange is below a predetermined temperature, the first and second solenoid valves are switched so that the first circulation path is configured. A heating system for a cab according to configuration 12, wherein the first and second electromagnetic switching valves are switched so that the second circulation path is configured when the temperature of the liquid heated by the heat exchange is equal to or greater than the predetermined temperature. [Composition 14] The heating system for the cab described in configuration 13, wherein the predetermined temperature is a constant temperature of 55°C or higher and 60°C or lower. [Composition 15] Equipped with an additional fuel cell stack, The fuel cell-related components are auxiliary components of the fuel cell stack, which are a heating system for the cab according to any one of configurations 11 to 14. [Composition 16] The steps include: switching an electromagnetic switching valve contained in a pipe through which liquid flows, thereby selectively configuring the pipe into a first circulation path and a second circulation path; In the first circulation channel, the steps include heating the liquid with an electric heater, The second circulation channel comprises the step of heating the liquid by heat exchange with fuel cell-related components, The first circulation channel is configured such that the liquid heated by the electric heater circulates through only the electric heater among the electric heater and the fuel cell related components, and through a heater core installed in the cab. A method for heating a cab, wherein the second circulation channel is configured to circulate only through the fuel cell-related components among the electric heater and the fuel cell-related components, and through the heater core, the liquid heated by the heat exchange circulates. [Composition 17] The first circulation path is configured such that the liquid heated by the electric heater circulates only through the electromagnetic switching valve and the heater core among the electromagnetic switching valve, the heater core and the radiator connected to the piping, The method for heating a cab according to configuration 16, wherein the second circulation path is configured such that the liquid heated by the heat exchange circulates through the electromagnetic switching valve, the heater core, and the radiator. [Composition 18] Each of the heater cores is positioned between the first solenoid valve and the second solenoid valve, which each serves as a solenoid switching valve. If the temperature of the liquid heated by the heat exchange is below a predetermined temperature, the controller switches the first and second solenoid valves so that the first circulation path is configured. A method for heating a cab according to configuration 17, further comprising the step of the controller switching the first and second solenoid valves so that the second circulation path is configured when the liquid heated by the heat exchange is above the predetermined temperature. [Composition 19] The heating method for the cab described in configuration 18, wherein the predetermined temperature is 55°C or higher and 60°C or lower. [Configuration 20] The aforementioned fuel cell-related components are auxiliary equipment for the fuel cell stack, and the method for heating a cab according to any one of configurations 16 to 19.

[0101] The embodiments disclosed herein are illustrative and not limited to those described above. The scope of the present invention is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of Symbols]

[0102] 1 Shovel, 11 Main body, 12 Working equipment, 13 Slewing body, 14 Cab, 14S Driver's seat, 15 Running body, 15Cr Tracks, 15M Travel motor, 16 Boom, 17 Arm, 18 Bucket, 19a Cylinder, 19a Boom cylinder, 19b Arm cylinder, 19c Bucket cylinder, 21 Hydrogen tank, 30 Fuel cell module, 31 Fuel cell stack, 32 Auxiliary equipment, 100, 620 Piping, 110 First piping section, 120 Second piping section, 130 Third piping section, 140 Fourth piping section, 150, 160 Solenoid switching valve, 151, 152, 153, 154, 161, 162, 163, 164 Port, 210 Electric heater, 211 Heating section, 220 Radiator, 230, 240 Pump, 250 Temperature sensor, 310 Controller, 320 Switch, 400 Housing, 411, 412, 413, 414, 415 Dampers, 420 Chamber, 491 Intake port, 492, 492C, 492L, 492R, 493 Air outlet, 494 Defroster outlet, 511, 512, 513 Motor, 601 Blower fan, 602 Evaporator, 603 Heater core, 700 External controller, 1000 Heating system, AT Arm top pin, BF Boom foot pin, BT Boom top pin, OP Exterior panel, R1, R2, R3 Circulation channel, RX Swivel axis.

Claims

1. Fuel cell related parts, The heater core installed inside the cab, Electric heater and, It comprises a solenoid valve and piping through which liquid flows, The aforementioned piping is configured to selectively consist of a first circulation path and a second circulation path by switching the solenoid valve. The first circulation channel is configured such that the liquid circulates only through the electric heater among the electric heater and the fuel cell related components, and through the heater core. A working machine in which the second circulation channel is configured to circulate the liquid via only the fuel cell-related components among the electric heater and the fuel cell-related components, and via the heater core.

2. In the first circulation channel, the liquid is heated by the electric heater. The working machine according to claim 1, wherein in the second circulation channel, the liquid is heated by heat exchange with the fuel cell-related components.

3. The system further includes a radiator connected to the aforementioned piping, The first circulation path is configured such that the liquid heated by the electric heater circulates only through the electromagnetic switching valve and the heater core among the electromagnetic switching valve, the heater core and the radiator. The working machine according to claim 2, wherein the second circulation channel is configured such that the liquid heated by the heat exchange circulates through the electromagnetic switching valve, the heater core, and the radiator.

4. The system further includes a controller for switching the aforementioned electromagnetic switching valve, The system further includes a sensor for measuring the temperature of the liquid heated by the aforementioned heat exchange, The solenoid switching valve includes a first and a second solenoid switching valve, The heater core is positioned between the first electromagnetic switching valve and the second electromagnetic switching valve. The aforementioned controller, If the temperature of the liquid heated by the heat exchange is below a predetermined temperature, the first and second electromagnetic switching valves are switched so that the first circulation path is configured. The working machine according to claim 3, wherein the first and second electromagnetic switching valves are switched so that the second circulation path is configured when the temperature of the liquid heated by the heat exchange is equal to or greater than the predetermined temperature.

5. The work machine according to claim 4, wherein the controller turns off the electric heater when the temperature of the liquid heated by the heat exchange is above a predetermined temperature.

6. The piping includes first to third piping sections, each connected to the first and second solenoid valves, The first piping section is positioned between the first electromagnetic switching valve and the second electromagnetic switching valve, with the heater core in between. The second piping section has the heating element of the electric heater located inside and is positioned between the first electromagnetic switching valve and the second electromagnetic switching valve. The third piping section is positioned between the first and second solenoid valves, with the radiator in between, and is in direct contact with the fuel cell-related components or in contact with a heat conductive material. The first circulation channel is composed of a first piping section and a second piping section. The working machine according to claim 4, wherein the second circulation channel is composed of the first piping section and the third piping section.

7. The first and second electromagnetic switching valves are four-way electromagnetic switching valves. The piping further includes a fourth bypass piping section connected to the first and second solenoid valves, The working machine according to claim 6, wherein when the first circulation channel is configured, the third piping section and the fourth piping section constitute a third circulation channel through which the liquid heated by the heat exchange circulates.

8. The liquid heated by the heat exchange circulates through the first electromagnetic switching valve, the heater core, the second electromagnetic switching valve, and the radiator in that order. The fuel cell-related components are installed between the radiator and the first electromagnetic switching valve. The work machine according to claim 6, wherein the sensor is installed between the fuel cell-related component and the first electromagnetic switching valve.

9. The work machine according to claim 4, wherein the predetermined temperature is a constant temperature of 55°C or more and 60°C or less.

10. The system further comprises a fuel cell stack and auxiliary equipment for the fuel cell stack, The fuel cell-related component is the auxiliary equipment, as described in any one of claims 1 to 9.

11. Fuel cell related parts, The heater core installed inside the cab of the work machine, Electric heater and, It comprises a solenoid valve and piping through which liquid flows, The aforementioned piping is configured to selectively consist of a first circulation path and a second circulation path by switching the solenoid valve. The first circulation channel is configured such that the liquid circulates only through the electric heater among the electric heater and the fuel cell related components, and through the heater core. A heating system for a cab, wherein the second circulation channel is configured to circulate the liquid via only the fuel cell-related components among the electric heater and the fuel cell-related components, and via the heater core.

12. The system further includes a radiator connected to the aforementioned piping, In the first circulation channel, the liquid is heated by the electric heater. In the second circulation channel, the liquid is heated by heat exchange with the fuel cell-related components. The first circulation path is configured such that the liquid heated by the electric heater circulates only through the electromagnetic switching valve and the heater core among the electromagnetic switching valve, the heater core and the radiator. The cab heating system according to claim 11, wherein the second circulation path is configured such that the liquid heated by the heat exchange circulates through the electromagnetic switching valve, the heater core, and the radiator.

13. The system further includes a controller for switching the aforementioned electromagnetic switching valve, The system further includes a sensor for measuring the temperature of the liquid heated by the aforementioned heat exchange, The solenoid switching valve includes a first and a second solenoid switching valve, The heater core is positioned between the first electromagnetic switching valve and the second electromagnetic switching valve. The aforementioned controller, If the temperature of the liquid heated by the heat exchange is below a predetermined temperature, the first and second electromagnetic switching valves are switched so that the first circulation path is configured. A heating system for a cab according to claim 12, wherein the first and second electromagnetic switching valves are switched so that the second circulation path is configured when the temperature of the liquid heated by the heat exchange is equal to or greater than the predetermined temperature.

14. The heating system for a cab according to claim 13, wherein the predetermined temperature is a constant temperature of 55°C or more and 60°C or less.

15. The system further comprises a fuel cell stack and auxiliary equipment for the fuel cell stack, The fuel cell-related component is the auxiliary equipment, as described in any one of claims 11 to 14, for the cab heating system.

16. The steps include: switching an electromagnetic switching valve contained in a pipe through which liquid flows, thereby selectively configuring the pipe into a first circulation path and a second circulation path; In the first circulation channel, the steps include heating the liquid with an electric heater, The second circulation channel comprises the step of heating the liquid by heat exchange with fuel cell-related components, The first circulation channel is configured such that the liquid heated by the electric heater circulates through only the electric heater among the electric heater and the fuel cell related components, and through a heater core installed in the cab. A method for heating a cab, wherein the second circulation channel is configured to circulate only through the fuel cell-related components among the electric heater and the fuel cell-related components, and through the heater core, the liquid heated by the heat exchange circulates.

17. The first circulation path is configured such that the liquid heated by the electric heater circulates only through the electromagnetic switching valve and the heater core among the electromagnetic switching valve, the heater core and the radiator connected to the piping, The method for heating a cab according to claim 16, wherein the second circulation path is configured such that the liquid heated by the heat exchange circulates through the electromagnetic switching valve, the heater core, and the radiator.

18. Each of the heater cores is positioned between the first solenoid valve and the second solenoid valve, which serve as the electromagnetic switching valves. If the temperature of the liquid heated by the heat exchange is below a predetermined temperature, the controller switches the first and second solenoid valves so that the first circulation path is configured. A method for heating a cab according to claim 17, further comprising the step of the controller switching the first and second solenoid valves so that the second circulation path is configured when the liquid heated by the heat exchange is above the predetermined temperature.

19. The method for heating a cab according to claim 18, wherein the predetermined temperature is 55°C or higher and 60°C or lower.

20. The method for heating a cab according to any one of claims 16 to 19, wherein the fuel cell-related component is an auxiliary component of the fuel cell stack.

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