Work machine

Abstract

To improve heat exchange efficiency in a work machine having a heat exchanger.SOLUTION: A work machine comprises: a machine frame; a fuel cell 24 mounted on the machine frame; an electric component E mounted on the machine frame; and an auxiliary heat exchanger 60 which conducts heat exchange between a first heat medium C1 which regulates a temperature of the fuel battery 24 and a second heat medium C2 which regulates a temperature of the electric component E.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a working machine.

Background Art

[0002] From the perspective of environmental protection, a working machine equipped with a fuel cell and driven by a motor rotated by the electric power generated by the fuel cell has been proposed (for example, see Patent Document 1). The working machine disclosed in Patent Document 1 is a tractor. Hydrogen is used as the fuel of the fuel cell. The tractor has electrical components such as a battery for storing the electric power generated by the fuel cell.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The tractor has a heat exchanger (radiator), and the heat exchanger exchanges heat between the heat medium passing through electrical components such as the fuel cell and the battery and the external air to cool it. If the capacity of the heat exchanger is increased, its performance will be improved. However, the enlargement of the heat exchanger is limited in relation to the mounting space. Therefore, an object of the present disclosure is to improve the heat exchange efficiency in a working machine having a heat exchanger.

Means for Solving the Problems

[0005] The working machine of the present disclosure includes a machine frame, a fuel cell mounted on the machine frame, electrical components mounted on the machine frame, and an auxiliary heat exchanger that exchanges heat between a first heat medium for adjusting the temperature of the fuel cell and a second heat medium for adjusting the temperature of the electrical components.

Effects of the Invention

[0006] According to the working machine of the present disclosure, it is possible to improve the heat exchange efficiency of the heat exchanger.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0008] <Summary of Embodiments of the Present Disclosure> Hereinafter, the summary of the embodiments of the present disclosure will be listed and described. (1) The working machine according to the embodiment of the present disclosure includes a machine frame, a fuel cell mounted on the machine frame, electrical components mounted on the machine frame, and an auxiliary heat exchanger that performs heat exchange between a first heat medium for temperature-adjusting the fuel cell and a second heat medium for temperature-adjusting the electrical components.

[0009] According to the working machine having the above configuration, for example, when the temperature of the first heat medium for temperature-adjusting the fuel cell is higher than that of the second heat medium for temperature-adjusting the electrical components, in the auxiliary heat exchanger, the temperature of the first heat medium is lowered by the second heat medium. Cooling of the fuel cell is performed using the first heat medium whose temperature has been lowered by the second heat medium. The heat exchange efficiency of the entire working machine is improved.

[0010] (2) The working machine of (1) has a first flow path through which the first heat medium passes to adjust the temperature of the fuel cell, and a second flow path through which the second heat medium passes to adjust the temperature of the electrical components. The auxiliary heat exchanger is connected to the first flow path and the second flow path. With the above configuration, a configuration in which heat exchange is performed between the first heat medium and the second heat medium by the auxiliary heat exchanger is obtained.

[0011] (3) The working machine of (2) has a first heat exchanger provided in the first flow path to adjust the temperature of the first heat medium that has passed through the fuel cell, and a second heat exchanger provided in the second flow path to adjust the temperature of the second heat medium that has passed through the electrical components. With the above configuration, the first heat exchanger can lower the temperature of the first heat medium that has passed through the fuel cell. The second heat exchanger can lower the temperature of the second heat medium that has passed through the electrical components.

[0012] (4) In the working machine of (3), the temperature of the first heat medium that has passed through the first heat exchanger is higher than the temperature of the second heat medium that has passed through the second heat exchanger. In the case of the above configuration, heat exchange is performed between the first heat medium with a high temperature and the second heat medium with a low temperature by the auxiliary heat exchanger. The fuel cell is cooled using the first heat medium whose temperature has been lowered by the second heat medium.

[0013] (5) In the working machine of (4), the first heat exchanger and the second heat exchanger have a difference in capacity with respect to the temperature decrease width due to heat exchange. For example, when the temperature decrease width of the first heat medium in the first heat exchanger is smaller than the temperature decrease width of the second heat medium in the second heat exchanger, the second heat exchanger may have relatively more capacity. In this case, the cooling of the fuel cell by the first heat medium is supplemented by the second heat medium.

[0014] (6) The working machine according to any one of (1) to (5) has a bypass flow path in which the auxiliary heat exchanger is connected in parallel to the flow path through which the second heat medium passes and through which the second heat medium flows. According to the above configuration, a part of the second heat medium passes through the auxiliary heat exchanger and heat exchange occurs between the second heat medium and the first heat medium. Another part of the second heat medium passes through the bypass flow path without passing through the auxiliary heat exchanger. That is, the above configuration is effective when it is not necessary to heat-exchange all of the second heat medium with the first heat medium in the auxiliary heat exchanger.

[0015] (7) The working machine according to (6) above has a bypass valve for adjusting the ratio of the second heat medium flowing through the bypass flow path. According to the above configuration, the amount of the second heat medium used for heat exchange in the auxiliary heat exchanger is adjusted.

[0016] (8) In any one of the working machines according to (1) to (3) above, the electrical components include a battery for storing the power generated by the fuel cell and a motor for generating driving power. At the start of operation of the working machine, it is preferable to perform a warm-up operation for the battery, which is the electrical component, and the rolling bearings of the motor. For the warm-up operation of the battery and the motor, the exhaust heat of the first heat exchanger (first heat medium) is utilized by the auxiliary heat exchanger, and the warm-up operation time of the electrical components can be shortened.

[0017] (9) The working machine according to (3) above has an air conditioner having a compressor, an expansion valve, an evaporator, and a condenser and having a cooling function using a third heat medium, and the evaporator exchanges heat between the first heat medium or the second heat medium and the third heat medium. According to the above configuration, the fuel cell or the electrical components are cooled using the first heat medium or the second heat medium whose temperature has been lowered by the third heat medium.

[0018] (10) The working machine according to (9) above has a battery and a heating unit for heating the battery using a fourth heat medium, and the condenser exchanges heat between the fourth heat medium and the third heat medium. When the temperature of the battery is low, its performance deteriorates. According to the above configuration, the fourth heat medium is heated by the exhaust heat of the air conditioner (the third heat medium), and the temperature of the battery can be efficiently increased by using the fourth heat medium.

[0019] (11) The working machine according to (9) or (10) above has a first valve for adjusting the flow rate of the first heat medium or the second heat medium passing through the evaporator. According to the above configuration, by, for example, feedback controlling the opening degree of the first valve, it is possible to adjust the auxiliary level by the third heat medium for the air conditioner.

[0020] (12) The working machine according to (10) above has a second valve for adjusting the flow rate of the fourth heat medium passing through the battery. According to the above configuration, by, for example, feedback controlling the opening degree of the second valve, it is possible to adjust the auxiliary level of the temperature increase of the battery by the third heat medium for the air conditioner.

[0021] (13) The heating unit in the working machine according to (10) above has an electric heater for heating the fourth heat medium. According to the above configuration, it is possible to quickly increase the temperature of the battery.

[0022] (14) The working machine according to the embodiment of the present disclosure includes a machine frame, a fuel cell mounted on the machine frame, electrical components mounted on the machine frame, a heat exchanger for adjusting the temperature of one or both of the fuel cell and the electrical components using a heat medium, and an air conditioner having a compressor, an expansion valve, an evaporator, and a condenser and having a cooling function using a third heat medium. The evaporator performs heat exchange between the heat medium and the third heat medium.

[0023] According to the working machine having the above configuration, for example, when the temperature of the heat medium that adjusts the temperature of one or both of the fuel cell and the electrical components is higher than that of the third heat medium for the air conditioner, in the auxiliary heat exchanger, the temperature of the heat medium is lowered by the third heat medium. Using the heat medium whose temperature has been lowered by the third heat medium, one or both of the fuel cell and the electrical components are cooled.

[0024] (15) The working machine according to (14) has a battery and a heating unit that raises the temperature of the battery using a fourth heat medium, and the condenser performs heat exchange between the fourth heat medium and the third heat medium. When the temperature of the battery is low, its performance deteriorates. According to the above configuration, the fourth heat medium is heated by the waste heat of the air conditioner (third heat medium), and it becomes possible to efficiently increase the temperature of the battery using the fourth heat medium. That is, it becomes possible to raise the temperature of the battery using the fourth heat medium whose temperature has been raised by the third heat medium.

[0025] <Details of Embodiments of the Present Disclosure> Hereinafter, with reference to the drawings, the details of the embodiments of the present disclosure will be described. Note that at least a part of the embodiments described below may be arbitrarily combined.

[0026] 〔Overall Structure of Working Machine〕 FIG. 1 is a perspective view showing an example of the overall structure of a working machine. The working machine of the present embodiment is a work vehicle used for agricultural work, specifically a tractor. The working machine is not limited to a tractor and may be a moving body such as a construction machine and a utility vehicle. Hereinafter, the case where the working machine is the work vehicle 10 will be described. FIG. 2 is a right side view of the work vehicle 10 with some exterior parts (such as the bonnet 34 and the cover 111) removed.

[0027] The work vehicle 10 has a chassis 41, a drive device 14, a driver's seat 15, a cabin 16, a bonnet 34, a cover 111, a tank unit 21, a first radiator 48, a second radiator 49, and a traveling device 12. The bonnet 34 and the cover 111 are mounted on the chassis 41 in order from the front to the rear of the work vehicle 10, and the cabin 16 is disposed behind the cover 111.

[0028] The cabin 16 has front pillars, rear pillars and a roof, and is a driver's cab partitioned by these. The work vehicle 10 may have a canopy or a rollover protective structure (ROPS) instead of the cabin 16. When the work vehicle 10 does not have the cabin 16, the tank unit 21 is disposed above the driver's seat 15 by the mounting frame 17.

[0029] As shown in FIG. 2, the second radiator 49, the fuel cell 24, and the first radiator 48 are mounted on the front portion of the chassis 41 in order from the front side to the rear side. The second radiator 49 and the fuel cell 24 are covered by the bonnet 43, and the first radiator 48 is covered by the cover 111.

[0030] The tank unit 21 has a tank 13 for storing fuel inside. The fuel stored inside is a liquid or a gas, such as hydrogen, methane, carbon monoxide (CO), etc. In this embodiment, the tank 13 stores hydrogen gas. The drive device 14 is driven by the stored fuel. The work vehicle 10 is a fuel cell vehicle (FCV: Fuel Cell Vehicle), and runs using the electric power generated by the chemical reaction of hydrogen and oxygen in the fuel cell 24 as an energy source. The fuel cell 24 may generate electric power by methane or carbon monoxide (CO).

[0031] The drive device 14 has a fuel cell 24, a battery 30, and an electric motor 31 (see FIG. 3). FIG. 3 is a perspective view showing an example of the internal structure of the work vehicle 10. The battery 30 has a battery pack 30A (see FIG. 4) for storing the output power of the fuel cell 24. FIG. 4 is a block diagram showing an example of the functional configuration of the work vehicle 10. The work vehicle 10 has a hydrogen gas pipe 22. The hydrogen gas is supplied from a filling port 52 (see FIG. 4) connected to the end of the pipe 22 and filled into the tank 13. The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the pipe 22.

[0032] The traveling device 12 is mounted on the chassis 41 and has front wheels 12A and rear wheels 12B. One or both of the front wheels 12A and the rear wheels 12B rotate by the power of the motor 31. One or both of the wheels 12A and 12B (drive wheels) that rotate by the power of the motor 31 may be crawlers (endless tracks).

[0033] 〔Internal Structure of Work Vehicle〕 The chassis 41 (see FIG. 3) is configured to have a steel frame that is long in the front-rear direction and has a front frame 32 and a gear case 33. The gear case 33 is connected to the rear part of the front frame 32. The skeleton of the work vehicle 10 is formed by the gear case 33 and the front frame 32. The chassis 41 having the front frame 32 and the gear case 33 serves as a vehicle body frame (mechanical frame) for mounting the drive device 14, the driver's seat 15, the cabin 16, etc.

[0034] A mounting frame 17 for the tank unit 21 is connected to the chassis 41. The mounting frame 17 supports the tank unit 21 above the cabin 16. The mounting frame 17 includes a substantially rectangular ceiling frame 17A whose front-rear direction is longer than the left-right direction, a plurality of pillars 17B that support the ceiling frame 17A from below, and a pair of left and right reinforcing frames 17C connected to the front end of the ceiling frame 17A. The tank unit 21 is connected to the ceiling frame 17A. The reinforcing frame 17C is a reinforcing diagonal member that inclines downward from the front end of the ceiling frame 17A to the front frame 32.

[0035] The support frame 37 is connected to the chassis 41, and the battery 30 is supported by the support frame 37. Specifically, the motor 31 is mounted on the front frame 32 of the chassis 41, and the support frame 37 is attached to the portion of the front frame 32 corresponding to the motor 31. The support frame 37 is made of, for example, a metal frame member and is attached in a cantilever state so as to protrude to the right from the front frame 32.

[0036] The gear case 33 located behind the motor 31 has a power transmission mechanism inside. The power transmission mechanism includes a transmission, a clutch, and a differential gear, and decelerates or accelerates the rotation of the output shaft of the motor 31 and transmits it to the traveling device 12. The power transmission mechanism inside the gear case 33 includes a branch mechanism that outputs a part of the power of the motor 31 to the PTO shaft 334 (see FIG. 2). The PTO shaft 334 is an output shaft that protrudes from the rear portion of the gear case 33.

[0037] The work vehicle 10 has a connecting device 43 (see FIG. 2) for connecting a work device 19 (see FIG. 4) for performing a desired agricultural work behind the work vehicle 10. The work device 19 is also called an implement. The work device 19 is, for example, a tiller and a baler. The rotational motion of the PTO shaft 334 is transmitted to the input shaft of the work device 19, for example, while the work vehicle 10 is traveling. The work vehicle 10 can drive the work device 19 by the power of the motor 31 while traveling in a field or the like.

[0038] 〔Functional Configuration of Work Vehicle〕 As shown in FIG. 4, the functional system of the work vehicle 10 includes a fuel system FS, a power system PS, and a temperature control system TS.

[0039] Components of the fuel system FS include the tank 13 and the valve unit 45. Components of the temperature control system TS include a first radiator 48, a second radiator 49, and an air conditioner (air conditioner) 80. Components of the power system PS include the fuel cell 24, the boost circuit 28, the DC / DC converter 26, the inverter 27, the battery 30, the motor 31, and the gear case 33. Hereinafter, the DC / DC converter 26 is also referred to as the "converter 26." In the present embodiment, the converter 26 has a first DC / DC converter 26A (also referred to as the "first converter 26A") and a second DC / DC converter 26B (also referred to as the "second converter 26B").

[0040] The tank 13 is connected to the first pipe 22A and the second pipe 22B via the valve unit 45. The first pipe 22A is a gas pipe that connects the filling port 52 and the valve unit 45, and guides hydrogen gas introduced into the filling port 52 to the tank 13. The second pipe 22B is a gas pipe that connects the fuel cell 24 and the valve unit 45, and guides hydrogen gas stored in the tank 13 to the fuel cell 24.

[0041] The valve unit 45 is an assembly of valves including an on-off valve and a pressure reducing valve. The valve unit 45 adjusts the flow rate of hydrogen gas in the tank 13 and outputs it to the fuel cell 24 by controlling the operation of the internal valves.

[0042] The motor 31 has a rotor and a stator having a plurality of coils, and drives an output shaft with a predetermined torque and rotational speed. In the present embodiment, only one motor 31 is mounted on the work vehicle 10, and the rotating shaft of the motor 31 is coupled to a gear case 33. The power transmission mechanism of the gear case 33 outputs a portion of the power of the motor 31 to the traveling device 12 and outputs the remainder of the power of the motor 31 to the PTO shaft 334.

[0043] The fuel cell 24 is, for example, a battery module in which a plurality of single cells each having a positive electrode and a negative electrode are arranged in parallel in a stacked state within a casing. The fuel cell 24 aggregates the electric power generated by each single cell to generate the electric power necessary for driving the electric motor 31. The fuel cell 24 is electrically connected to a boost circuit 28, and the boost circuit 28 is electrically connected to an inverter 27.

[0044] The boost circuit 28 boosts the voltage input from the fuel cell 24 and outputs it to the inverter 27. The inverter 27 is electrically connected to the motor 31. The inverter 27 converts the DC power input from the boost circuit 23 into three-phase AC power and outputs it to the motor 31. The electric power generated by the fuel cell 24 is boosted and converted into AC power and transmitted to the motor 31.

[0045] The work vehicle 10 has electrical components with a low voltage that operate at a voltage lower than that of the motor 31. For these electrical components, DC power stepped down by a step-down circuit is supplied. The electrical components with a low voltage are, for example, the battery 30, the first fan 35 of the first radiator 48, the second fan 36 of the second radiator 49, and the air conditioner 80. The step-down circuit is the converter 26, and in the case of this embodiment, the first converter 26A and the second converter 26B.

[0046] The first converter 26A steps down the DC voltage input from the boost circuit 28 and supplies it to the battery 30 and the air conditioner 80. The second converter 26B steps down the DC voltage input from the boost circuit 28 and supplies it to the first fan 35 of the first radiator 48 and the second fan 36 of the second radiator 49.

[0047] The inverter 27 and the converters 26 (the first converter 26A and the second converter 26B) are attached to the chassis 41 that serves as the vehicle body frame. The inverter 27 and the converters 26 are mounted in the vicinity of the driver's seat 15.

[0048] The battery 30 is a power storage device that temporarily stores the power supplied to the motor 31. The battery 30 has a battery pack 30A. The battery pack 30A includes at least one battery. The battery is a charge-discharge type battery such as, for example, a lithium-ion battery or a lead-acid battery.

[0049] 〔Regarding the temperature control system TS〕 FIG. 5 is an explanatory diagram showing an example of the temperature control system TS. The temperature control system TS will be described with reference to FIGS. 4 and 5. The temperature control system TS has a first radiator 48, a second radiator 49, and an air conditioner 80.

[0050] The first radiator 48 is a first heat exchanger included in a first cooling unit U1 for cooling the fuel cell 24 with a first heat medium (first coolant) C1. The second radiator 49 is a second heat exchanger included in a second cooling unit U2 for cooling electrical components E including the motor 31 and the like with a second heat medium (second coolant) C2.

[0051] A first flow path (first pipe) H1 is connected to the first radiator 48. The first flow path H1 is a circulation flow path, and the first heat medium C1 is circulated through the first flow path H1 by a pump 47. The first flow path H1 passes through the first radiator 48. The first radiator 48 exchanges heat between the first heat medium C1 and the outside air and cools the first heat medium C1. The first radiator 48 has a first fan 35 for promoting heat exchange. The object to be cooled by the first cooling unit U1 including the first radiator 48 and the flow path H1 is the fuel cell 24.

[0052] A second radiator 49 is connected to a second flow path (second pipe) H2. The second flow path H2 is a circulation flow path, and a second heat medium C2 circulates through the second flow path H2 by a pump 46. The second flow path H2 passes through the second radiator 49. The second radiator 49 exchanges heat between the second heat medium C2 and the outside air to cool the second heat medium C2. The second radiator 49 has a second fan 36 for promoting heat exchange. The object to be cooled by the second cooling unit U2 including the second radiator 49 and the flow path H2 is an electrical component E that generates heat, such as a first converter 26A, a second converter 26B, a battery 30, a motor 31, an inverter 27, and a boost circuit 28.

[0053] As described above, the temperature control system TS has a first flow path H1 that adjusts the temperature of the fuel cell 24 by allowing the first heat medium C1 to pass through it, and a second flow path H2 that adjusts the temperature of the electrical component E by allowing the second heat medium C2 to pass through it. The first radiator 48 is provided in the first flow path H1 and adjusts (cools) the temperature of the first heat medium C1 that has passed through the fuel cell 24. The second radiator 49 is provided in the second flow path H2 and adjusts (cools) the temperature of the second heat medium C2 that has passed through the electrical component E.

[0054] The temperature control system TS further has an auxiliary radiator as an auxiliary heat exchanger 60. The auxiliary heat exchanger 60 is connected to the first flow path H1 and the second flow path H2. That is, the first flow path H1 and the second flow path H2 pass through the auxiliary heat exchanger 60. The auxiliary heat exchanger 60 exchanges heat between the first heat medium C1 in the first flow path H1 and the second heat medium C2 in the second flow path H2.

[0055] In the case of this embodiment, the flow rate of the first heat medium C1 flowing through the first flow path H1 is larger than the flow rate of the second heat medium C2 flowing through the second flow path H2. The first radiator 48 and the second radiator 49 have a difference in ability regarding the temperature drop width due to heat exchange. In the case of this embodiment, as shown in FIG. 5, the temperature drop width ΔT1 of the first heat medium C1 in the first radiator 48 is smaller than the temperature drop width ΔT2 of the second heat medium C2 in the second radiator 49.

[0056] The temperature t11 of the first heat medium C1 that has passed through the first radiator 48 is higher than the temperature t21 of the second heat medium C2 that has passed through the second radiator 49. Heat exchange is performed between the first heat medium C1 with a higher temperature and the second heat medium C2 with a lower temperature by the auxiliary heat exchanger 60. In FIG. 5, it is assumed that the temperature t13 of the first heat medium C1 after passing through the fuel cell 24 and before passing through the first radiator 48 is the same as the temperature t23 of the second heat medium C2 after passing through all the electrical components E and before passing through the second radiator 49, and each temperature is illustrated.

[0057] Due to the heat exchange between the first heat medium C1 and the second heat medium C2 in the auxiliary heat exchanger 60, the temperature t22 of the second heat medium C2 after passing through the auxiliary heat exchanger 60 becomes higher than the temperature t21 of the second heat medium C2 before passing through the auxiliary heat exchanger 60. On the contrary, the temperature t12 of the first heat medium C1 after passing through the auxiliary heat exchanger 60 becomes lower than the temperature t11 of the first heat medium C1 before passing through the auxiliary heat exchanger 60.

[0058] The first heat medium C1, which has become lower in temperature due to the auxiliary heat exchanger 60, passes through the fuel cell 24. Using the first heat medium C1 whose temperature has been lowered by the second heat medium C2, the fuel cell 24 is cooled. That is, the cooling of the fuel cell 24 is supplemented by the second heat medium C2.

[0059] The second flow path H2 has a flow path 62 through which the second heat medium C2 passes through the auxiliary heat exchanger 60. A bypass flow path 61 is provided in the second flow path H2. That is, the temperature control system TS has a bypass flow path 61 that is connected in parallel with the flow path 62 and through which the second heat medium C2 flows. A part of the second heat medium C2 in the second flow path H2 passes through the auxiliary heat exchanger 60 (flow path 62), and heat exchange is performed between the second heat medium C2 and the first heat medium C1. Another part of the second heat medium C2 can circulate through the bypass flow path 61 without passing through the auxiliary heat exchanger 60 (flow path 62).

[0060] The temperature control system TS has a bypass valve 63. In the form shown in FIG. 5, the bypass valve 63 is provided in the middle of the bypass passage 61. The opening degree of the bypass valve 63 is adjusted and controlled by a control device 70 (see FIG. 4) of the work vehicle 10. The bypass valve 63 may be provided at a branch portion 64 between the second flow path H2 and the bypass flow path 61. In this case, the bypass valve 63 becomes a three-way valve.

[0061] According to the bypass passage 61, it becomes effective when it is not necessary to exchange heat between all of the second heat medium C2 and the first heat medium C1 in the auxiliary heat exchanger 60. Further, according to the bypass valve 63, the amount (flow rate) of the second heat medium C2 used for heat exchange in the auxiliary heat exchanger 60 is adjusted. The bypass valve 63 can open the valve body at a fully open, fully closed, or intermediate opening degree. By adjusting the opening degree of the bypass valve 63, the flow rate of the second heat medium C2 flowing through the bypass passage 61 is adjusted.

[0062] As will be described later, at the start of operation of the work vehicle 10, it is preferable to perform a warm-up operation for the battery 30 which is an electrical component E and the rolling bearing (not shown) of the motor 31. For the warming operation, the opening degree of the bypass valve 63 is reduced so that a relatively large amount of the second heat medium C2 flows through the auxiliary heat exchanger 60 (flow path 62). When the warming is not required or when the assistance of the first radiator 48 is not required, the opening degree of the bypass valve 63 is increased so that a relatively large amount of the second heat medium C2 flows through the bypass passage 61.

[0063] As described above, according to the bypass passage 61, the second heat medium C2 is distributed to the flow path 62 passing through the auxiliary heat exchanger 60 and the bypass passage 61. By adjusting the opening degree of the bypass valve 63, the ratio of the second heat medium C2 flowing through the bypass passage 61 is adjusted. According to the bypass valve 63, it is also possible to make the second heat medium C2 flowing through the bypass passage 61 zero. When the bypass valve 63 is provided at the branch portion 64, it is also possible to make the second heat medium C2 flowing through the auxiliary heat exchanger 60 (flow path 62) zero.

[0064] Although not shown, a valve may be provided in the flow path from the branch portion 64 to the auxiliary heat exchanger 60 side. By adjusting the opening degree of the valve, the flow rate of the second heat medium C2 flowing through the auxiliary heat exchanger 60 (flow path 62) can be adjusted, and it is also possible to set the flow rate to zero.

[0065] 〔Modification example of the temperature control system TS〕 FIG. 6 is an explanatory diagram showing a modification example of the temperature control system TS. The temperature control system TS shown in FIG. 6 has the configuration of the temperature control system TS shown in FIG. 5, and also has an air conditioner 80 and a heating unit 72. The heating unit 72 is a device that raises the temperature of the battery 30 using the fourth heat medium C4. In FIG. 6, the configuration of the temperature control system TS shown in FIG. 5 is omitted.

[0066] The air conditioner 80 has a compressor 81, an expansion valve 82, an evaporator 83, and a condenser 84, and has a cooling function using the third heat medium C3. The air conditioner 80 adjusts the temperature (cools) the inside of the cabin 16, for example, or cools a device (for example, a heat generating product such as the control device 70) of the work vehicle 10. The air conditioner 80 has a circulation pipe 85 through which the third heat medium C3 passes. The compressor 81, the expansion valve 82, the evaporator 83, and the condenser 84 are provided in each part of the circulation pipe 85. The third heat medium C3 in the evaporator 83 is lower in temperature than one or both of the first heat medium C1 and the second heat medium C2.

[0067] The evaporator 83 performs heat exchange between the third heat medium C3 and the first heat medium C1 or the second heat medium C2. That is, the first flow path H1 through which the first heat medium C1 flows passes through the evaporator 83, and heat exchange is performed between the first heat medium C1 and the third heat medium C3 in the evaporator 83. Or, the second flow path H2 through which the second heat medium C2 flows passes through the evaporator 83, and heat exchange is performed between the second heat medium C2 and the third heat medium C3 in the evaporator 83. Or, both the first flow path H1 and the second flow path H2 pass through the evaporator 83, and heat exchange may be performed between the first heat medium C1 and the third heat medium C3, and heat exchange may be performed between the second heat medium C2 and the third heat medium C3 in the evaporator 83.

[0068] In the evaporator 83, the temperature of the first heat medium C1 or the second heat medium C2 is lowered by the third heat medium C3. The fuel cell 24 is cooled by the first heat medium C1 with its temperature lowered, and the electrical components E are cooled by the second heat medium C2 with its temperature lowered. That is, according to the temperature control system TS shown in FIG. 6, the cooling of the fuel cell 24 or the electrical components E is supplemented by the third heat medium C3.

[0069] The temperature control system TS shown in FIG. 6 has a valve (first valve) 87 provided in the first flow path H1 or the second flow path H2. The valve 87 can arbitrarily change the opening degree of its valve element, and adjusts the flow rate of the first heat medium C1 or the second heat medium C2 passing through the evaporator 83. The opening degree of the valve 87 is controlled by the control device 70. The opening degree of the valve 87 is feedback-controlled based on, for example, the temperature of the first heat medium C1 or the temperature of the second heat medium C2. Thereby, it becomes possible to adjust the auxiliary level of the third heat medium C3 with respect to the first radiator 48 side or the second radiator 49 side.

[0070] As described above, the temperature control system TS shown in FIG. 6 has a heating unit 72 that raises the temperature of the battery 30 using the fourth heat medium C4. The heating unit 72 has a circulation flow path 88 that circulates the fourth heat medium C4 and a valve (second valve) 89. The heating unit 72 has an electric heater 90 that heats the fourth heat medium C4. The electric heater 90 enables the battery 30 to be quickly heated.

[0071] The fourth heat medium C4 in the condenser 84 may be lower in temperature than the third heat medium C3. In this case, the condenser 84 performs heat exchange between the fourth heat medium C4 and the third heat medium C3. Here, when the temperature of the battery 30 is low, its performance deteriorates. By performing heat exchange between the fourth heat medium C4 and the third heat medium C3 in the condenser 84, it becomes possible to raise the temperature of the fourth heat medium C4 by the waste heat of the air conditioner 80 (third heat medium C3). It becomes possible to efficiently increase the temperature of the battery 30 using the fourth heat medium C4.

[0072] Valve 89 is provided in the middle of the circulation passage 88. Valve 89 adjusts the flow rate of the fourth heat medium C4 passing through the battery 30. The opening degree of valve 89 is controlled by the control device 70. The opening degree of valve 89 is feedback-controlled based on, for example, the temperature of the battery 30. With this configuration, it becomes possible to adjust the auxiliary level by the third heat medium C3 for the heating unit 72.

[0073] 〔Work vehicle 10 of the present embodiment〕 As described above, the work vehicle 10 of the present embodiment (see FIG. 5) includes a fuel cell 24, electrical components E such as a motor 31, and an auxiliary heat exchanger 60. The auxiliary heat exchanger 60 performs heat exchange between a first heat medium C1 that adjusts the temperature (cools) the fuel cell 24 and a second heat medium C2 that adjusts the temperature (cools) each electrical component E. In the case of the present embodiment, the temperature t11 of the first heat medium C1 that has passed through the first radiator 48 after cooling the fuel cell 24 is higher than the temperature t21 of the second heat medium C2 that has passed through the second radiator 49 after cooling the electrical component E (t11 > t21).

[0074] The auxiliary heat exchanger 60 performs heat exchange between the first heat medium C1 and the second heat medium C2. That is, the first heat medium C1 with a high temperature is cooled by the second heat medium C2 with a low temperature. The fuel cell 24 is cooled by the first heat medium C1 cooled in this way. That is, the cooling of the fuel cell 24 is supplemented by the second heat medium C2. As a result, the heat exchange efficiency of the entire work vehicle 10 is improved. In particular, there is a possibility of miniaturizing the first radiator 48.

[0075] In the case of the work vehicle 10 of the present embodiment, the electrical component E includes a battery 30 that stores the electric power generated by the fuel cell 24, and a motor 31 that generates traveling power. At the start of operation of the work vehicle 10, it is preferable to perform a warm-up operation due to the battery 30, which is the electrical component E, and the rolling bearings (not shown) of the motor 31. For the warm-up operation of the battery 30 and the motor 31, the exhaust heat of the first radiator 48 (first heat medium C1) is utilized by the auxiliary heat exchanger 60, enabling the warm-up operation of the electrical component E to be shortened in time.

[0076] 〔Work vehicle 10 having another temperature control system TS〕 FIG. 7 is an explanatory diagram of the temperature control system TS of the work vehicle 10 different from the forms shown in FIGS. 5 and 6. The work vehicle 10 having the configuration shown in FIG. 7 is the same as the work vehicle 10 shown in FIG. 1 except for the temperature control system TS. That is, the work vehicle 10 has a chassis 41 that is a machine frame, a fuel cell 24 mounted on the chassis 41, and an electrical component E mounted on the chassis 41.

[0077] The temperature control system TS shown in FIG. 7 has a radiator 91 as a heat exchanger. The radiator 91 adjusts the temperature of one or both of the fuel cell 24 and the electrical component E using the heat medium C5. In the case of the form shown in FIG. 7, the temperature control system TS has a circulation flow path 92 that passes through the radiator 91, and the heat medium C5 flowing through the circulation flow path 92 passes through both the fuel cell 24 and the electrical component E and is used for temperature adjustment (cooling) of the fuel cell 24 and the electrical component E.

[0078] The temperature control system TS shown in FIG. 7 has an air conditioner 80 and a heating unit 72 that raises the temperature of the battery 30 using the fourth heat medium C4. The air conditioner 80 has a compressor 81, an expansion valve 82, an evaporator 83, and a condenser 84, and is provided with a cooling function using the third heat medium C3. The heating unit 72 raises the temperature of the battery 30 using the fourth heat medium C4. The air conditioner 80 and the heating unit 72 are the same as the air conditioner 80 and the heating unit 72 shown in FIG. 6.

[0079] The circulation passage 92 has a bypass passage 95. A valve 87 is provided in the bypass passage 95. The valve 87 can arbitrarily change the opening degree of its valve body and adjusts the flow rate of the heat medium C5 passing through the evaporator 83. Its function is the same as that of the valve 87 in the temperature control system TS shown in FIG. 6. The heating unit 72 has an electric heater 90 that heats the fourth heat medium C4. The electric heater 90 enables the battery 30 to be quickly heated up.

[0080] When the temperature of the heat medium C5 is higher than that of the third heat medium C3 for the air conditioner 80, the evaporator 83 performs heat exchange between the heat medium C5 flowing through the bypass passage 95 and the third heat medium C3. The temperature of the heat medium C5 is lowered by the third heat medium C3. Using the heat medium C5 whose temperature has been lowered by the third heat medium C3, the fuel cell 24 and the electrical components E are cooled. That is, the cooling of the fuel cell 24 and the electrical components E is supplemented by the third heat medium C3.

[0081] The condenser 84 performs heat exchange between the fourth heat medium C4 and the third heat medium C3. When the temperature of the battery 30 is low, its performance deteriorates. By performing heat exchange between the fourth heat medium C4 and the third heat medium C3 in the condenser 84, the fourth heat medium C4 is heated up by the exhaust heat of the air conditioner 80 (the third heat medium C3). Using the fourth heat medium C4, it becomes possible to efficiently increase the temperature of the battery 30.

[0082] [Others] The above embodiments are illustrative in all respects and not restrictive. The scope of the rights of the present invention is shown not by the above embodiments but by the claims, and includes all modifications within the scope equivalent to the configurations described in the claims.

Explanation of Reference Numerals

[0083] 10 Work vehicle (working machine) 24 Fuel cell 30 Battery 31 Motor 41 Chassis (mechanical frame) 48 First radiator (first heat exchanger) 49 Second radiator (first heat exchanger) 60 Auxiliary heat exchanger 61 Bypass flow path 62 Flow path 63 Bypass valve 72 Heating unit 80 Air conditioner 81 Compressor 82 Expansion valve 83 Evaporator 84 Condenser 87 Valve (first valve) 89 Valve (second valve) 90 Electric heater 91 Radiator (heat exchanger) C1 First heat medium C2 Second heat medium C3 Third heat medium C4 Fourth heat medium C5 Heat medium E Electrical components H1 First flow path H2 Second flow path

Claims

1. A machine frame, a fuel cell mounted on the machine frame, electrical components mounted on the machine frame, and an auxiliary heat exchanger that performs heat exchange between a first heat medium for temperature-adjusting the fuel cell and a second heat medium for temperature-adjusting the electrical components. A work machine having the above components.

2. A first flow path through which the first heat medium passes to adjust the temperature of the fuel cell, and a second flow path through which the second heat medium passes to adjust the temperature of the electrical components. The work machine according to claim 1, further comprising: wherein the auxiliary heat exchanger is connected to the first flow path and the second flow path. The work machine according to claim 1.

3. A first heat exchanger provided in the first flow path to adjust the temperature of the first heat medium that has passed through the fuel cell, and a second heat exchanger provided in the second flow path to adjust the temperature of the second heat medium that has passed through the electrical components. The work machine according to claim 2, further comprising:

4. The temperature of the first heat medium that has passed through the first heat exchanger is higher than the temperature of the second heat medium that has passed through the second heat exchanger. The work machine according to claim 3.

5. The first heat exchanger and the second heat exchanger have a difference in capacity with respect to the temperature decrease width due to heat exchange. The work machine according to claim 4.

6. The work machine according to claim 1 or claim 2, further comprising: a bypass flow path in which the auxiliary heat exchanger is connected in parallel with the flow path through which the second heat medium passes and through which the second heat medium flows.

7. The work machine according to claim 6, further comprising: a bypass valve that adjusts the ratio of the second heat medium flowing through the bypass flow path.

8. The electrical components include a battery that stores electric power generated by the fuel cell and a motor that generates driving power. The work machine according to claim 1.

9. An air conditioner having a compressor, an expansion valve, an evaporator, and a condenser and having a cooling function using a third heat medium, wherein the evaporator performs heat exchange between the first heat medium or the second heat medium and the third heat medium. The work machine according to claim 3.

10. A battery, and a heating unit that heats the battery using a fourth heat medium. The work machine according to claim 9, further comprising: wherein the condenser performs heat exchange between the fourth heat medium and the third heat medium. The work machine according to claim 9.

11. The work machine according to claim 9 or claim 10, further comprising: a first valve that adjusts the flow rate of the first heat medium or the second heat medium passing through the evaporator.

12. A second valve for adjusting the flow rate of the fourth heat medium passing through the battery The work machine according to claim 10.

13. The heating unit has an electric heater for heating the fourth heat medium. The work machine according to claim 10.

14. A machine frame, A fuel cell mounted on the machine frame, Electrical components mounted on the machine frame, A heat exchanger for adjusting the temperature of one or both of the fuel cell and the electrical components using a heat medium, An air conditioner having a compressor, an expansion valve, an evaporator, and a condenser and equipped with a cooling function using a third heat medium, having, The evaporator performs heat exchange between the heat medium and the third heat medium, Work machine.

15. A battery, A heating unit for raising the temperature of the battery using a fourth heat medium, having, The condenser performs heat exchange between the fourth heat medium and the third heat medium, The work machine according to claim 14.

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