Hydrogen fuel system

Abstract

A hydrogen fuel system for a work machine is disclosed. The hydrogen fuel system comprises a hydrogen storage tank containing hydrogen, and the hydrogen is at least one of liquid hydrogen or gaseous hydrogen; a hydrogen power unit configured to consume hydrogen from the hydrogen storage tank, the hydrogen power unit including at least one of a plurality of fuel cells or hydrogen combustion engines; a vaporization pressure relief valve in fluid communication with the hydrogen storage tank; and a canister pressure sensor in communication with the vaporization pressure relief valve. The vaporization pressure relief valve is configured to discharge gaseous hydrogen to a vaporization fuel line fluidly connected to the hydrogen power unit when the tank pressure sensor detects that the pressure within the hydrogen storage tank exceeds a vaporization pressure threshold.

Description

Technical Field

[0001] The present invention relates generally to hydrogen fuel systems, and more particularly to hydrogen powered fuel systems having improved fuel economy. Background Art

[0002] Hydrogen ("H2") power units such as fuel cells, hydrogen fueled internal combustion engines and their associated fuel storage systems play an important role in the pursuit of clean and efficient energy solutions. Liquid hydrogen storage, also known as cryogenic hydrogen storage or cryogenic compression storage, is a method of hydrogen storage and preservation for hydrogen-powered applications. Hydrogen fuel cells are electrochemical devices that convert the chemical energy stored in hydrogen fuel into electricity, with water as a byproduct. Fuel cells operate through a redox reaction between hydrogen and oxygen, typically using a proton exchange membrane (PEM) or an alkaline electrolyte. On the other hand, hydrogen internal combustion engines operate similarly to conventional internal combustion engines, but use hydrogen as a fuel instead of gasoline or diesel.

[0003] Liquid hydrogen storage involves cooling hydrogen gas to very low temperatures (-253°C or 20K) to convert it into a liquid state that is more energy dense than gaseous hydrogen, allowing more hydrogen to be stored in a given volume. Liquid hydrogen is typically stored in specialized cryogenic tanks with insulation to minimize heat transfer and evaporation. Cryogenic tanks may be vacuum insulated to minimize evaporation losses and contain a decompression device as a safety precaution to prevent over-pressurization and avoid explosion.

[0004] When hydrogen fuel is not being drawn from the storage tank, such as when the machine is not operating or in sleep mode, evaporation of the liquid hydrogen occurs due to ambient conditions, causing pressure to build up inside the tank. The pressure inside the tank is usually released by venting the gaseous hydrogen to the atmosphere, resulting in a waste of hydrogen fuel.

[0005] Others have attempted to develop systems that consume gaseous hydrogen fuel, but have not disclosed methods for conserving hydrogen when the machine is inactive. For example, Korean application KR100969009 (hereinafter referred to as the "'009 reference") discloses a battery charging device for a fuel cell vehicle that stores hydrogen supplied to generate electricity. The battery charging device is configured to activate the fuel cell to discharge vaporized hydrogen to be consumed when a pressure sensor reaches a pressure threshold. However, the '009 reference does not provide a system for conserving hydrogen fuel when the machine is inactive, in a sleep mode, and stopped or in a sleep state for an extended period of time (e.g., greater than 3 days) at night.

[0006] It can therefore be seen that it is necessary to preserve the gaseous hydrogen formed when liquid hydrogen evaporates in the hydrogen storage tank of the hydrogen fuel system. Summary of the invention

[0007] According to one aspect of the present invention, a hydrogen fuel system for a working machine is disclosed. The hydrogen fuel system includes a hydrogen storage tank containing hydrogen, the hydrogen being at least one of liquid hydrogen and gaseous hydrogen; a hydrogen power unit configured to consume liquid hydrogen and gaseous hydrogen from the hydrogen storage tank, the hydrogen power unit being selected from one of a plurality of fuel cells and hydrogen combustion engines; a vaporization pressure relief valve in fluid communication with the hydrogen storage tank; and a tank pressure sensor in communication with the vaporization pressure relief valve. The vaporization pressure relief valve is configured to discharge gaseous hydrogen to a vaporization fuel line hydraulically connected to the hydrogen power unit when the tank pressure sensor detects that the pressure within the hydrogen storage tank exceeds a vaporization pressure threshold.

[0008] According to another aspect of the present invention, a working machine is disclosed. The working machine includes a frame; a ground engaging element supporting the frame; a battery supported by the frame; a plurality of machine operating systems, each having a plurality of system batteries; and a hydrogen fuel conservation system. The hydrogen fuel conservation system includes: a hydrogen storage tank mounted in the frame and containing hydrogen, the hydrogen being at least one of liquid hydrogen and gaseous hydrogen; a hydrogen power unit mounted in the frame and in fluid connection with the hydrogen storage tank and configured to consume liquid hydrogen and gaseous hydrogen, the hydrogen power unit being selected from one of a plurality of fuel cells and a hydrogen combustion engine; a tank pressure sensor within the hydrogen storage tank; a controller in communication with the tank pressure sensor and a plurality of machine operating systems; and a vaporization pressure relief valve in fluid communication with the hydrogen storage tank and in electrical communication with the tank pressure sensor. The vaporization pressure relief valve is configured to discharge gaseous hydrogen to a vaporization fuel line hydraulically connected to the hydrogen power unit when the tank pressure sensor detects that the pressure within the hydrogen storage tank exceeds a vaporization pressure threshold. The vaporized fuel line is configured to deliver the gaseous hydrogen to the hydrogen power unit for consumption of the gaseous hydrogen to generate electrical energy for powering and recharging the battery and the plurality of system batteries.

[0009] According to another aspect of the present invention, a method for storing hydrogen fuel in a hydrogen fuel system of a working machine is disclosed. The method comprises the following steps: providing a hydrogen storage tank connected to a hydrogen power unit fluid, the hydrogen power unit being selected from one of a fuel cell and a hydrogen internal combustion engine, the hydrogen storage tank containing at least one of liquid hydrogen and gaseous hydrogen; installing a vaporization pressure relief valve connected to the hydrogen storage tank, the vaporization pressure relief valve being configured to discharge gaseous hydrogen to a vaporization fuel pipeline connected to the vaporization pressure relief valve and the hydrogen power unit fluid, for releasing the pressure in the hydrogen storage tank; and when the working machine is in an inactive state or an operating state, transmitting gaseous hydrogen to the hydrogen power unit via the vaporization fuel pipeline for hydrogen fuel consumption and electricity production by the hydrogen power unit.

[0010] These and other aspects and features of the present invention will be better understood when the following detailed description is read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a perspective view of a working machine according to an embodiment of the present invention.

[0012] Figure 2 is a perspective cross-sectional view of an H2 storage tank for a working machine according to an embodiment of the present invention.

[0013] Figure 3 is connected to a hydrogen power unit according to an embodiment of the present invention Figure 2 Schematic diagram of the H2 storage tank.

[0014] Figure 4 According to an embodiment of the present invention Figure 1 Schematic diagram of the H2 fuel system in the working machine.

[0015] Figure 5 is a schematic diagram of a second H2 fuel system according to another embodiment of the present invention.

[0016] Figure 6 is a schematic diagram of a third H2 fuel system according to another embodiment of the present invention.

[0017] Figure 7 is a flow chart of the operation of an H 2 fuel system according to an embodiment of the present invention.

[0018] Figure 8 According to an embodiment of the present invention Figure 1 Flow chart of a method for storing hydrogen in an H2 fuel system of an operating machine.

[0019] The accompanying drawings depict one embodiment of the disclosed content presented for the purpose of illustration only. Those skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods shown herein may be employed without departing from the principles described herein. DETAILED DESCRIPTION

[0020] Referring now to the drawings, and with particular reference to the depicted example, there is shown a work machine 100, which is illustrated as an exemplary excavator. An excavator is a heavy mobile device designed to move earthen material from the ground or landscape at an excavation site in the construction and agricultural industries. Although the following detailed description describes exemplary aspects related to an excavator, it should be understood that the description is equally applicable to the use of the present invention in other mobile and stationary work machines, including but not limited to generators, backhoes, front-end loaders, shovels, draglines, skid steers, wheel loaders, and tractors.

[0021] Reference now Figure 1, the work machine 100 includes a ground engaging element 102, illustrated as a continuous crawler supporting a frame 104. It is contemplated that the ground engaging element 102 may be any other type of ground engaging element 102, such as wheels, etc. The work machine 100 also includes an H2 power unit 106, a battery 108, and an H2 storage tank 110 mounted on the frame 104. The machine may include a work implement 112 extending from the frame 104 for performing work, such as digging terrain or otherwise moving dirt, soil, or other materials at a digging site. The frame 104 may have an upper rotating body common to excavators and work machines in the agricultural and construction industries. The H2 power unit 106 may be provided as a plurality of fuel cells, a fuel cell stack, or as an H2 combustion engine, as is generally known in the art. The H2 storage tank 110 may be disposed in or on the frame 104 for storing liquid hydrogen, cryogenic compressed hydrogen, or cryogenic hydrogen fuel for the work machine 100.

[0022] Reference now Figure 2 , showing a perspective cross-sectional view of an H2 storage tank 110 according to one embodiment of the present invention. The H2 storage tank 110 may be constructed of high-strength materials, such as stainless steel, carbon fiber reinforced composite materials, or aluminum alloys, which provide sufficient strength and insulation properties. The H2 storage tank 110 may include a high-pressure vessel 200, which may be made of carbon fiber, steel, or other suitable high-strength materials capable of high-pressure storage, as is known in the art.

[0023] The H2 storage tank 110 may also include a shell 202, which may form a double-walled structure around the high-pressure vessel 200, with an annular space 204 in the double-walled structure. The shell 202 may be made of a high-strength material, such as stainless steel, to provide the necessary strength and insulation properties. The H2 storage tank 110 may also include a valve 206, a gaseous H2 outlet line 208 for releasing H2 gas, and a liquid H2 filling line 210 for filling liquid hydrogen into the H2 storage tank 110. A cryogenic pump designed to transfer liquid hydrogen from a storage filling tank to the H2 storage tank 110 may be used to prevent hydrogen from vaporizing during the transfer process.

[0024] Reference now Figure 3 , according to one embodiment of the present invention, a schematic diagram showing a schematic diagram of a power unit 106 connected to the H2 power unit 106. Figure 2Schematic diagram of H2 storage tank 110. H2 storage tank 110 includes liquid hydrogen 300, which may also be cryogenic hydrogen fuel or cryogenic compressed hydrogen. In some cases, due to changing pressure, temperature and environmental conditions, liquid hydrogen 300 has a tendency to vaporize into liquid-gaseous hydrogen phase 302 and gaseous hydrogen 304. H2 storage tank 110 may include a vaporization pressure release valve 306 for releasing a certain amount of gaseous hydrogen 304 when the volume of gaseous hydrogen 304 increases and the pressure in H2 storage tank 110 exceeds a vaporization pressure safety threshold.

[0025] When the liquid hydrogen 300 changes to gaseous hydrogen 304 due to the changing pressure, temperature, and ambient conditions of the working machine 100, the liquid hydrogen 300 vaporizes into gaseous hydrogen 304. The vaporization pressure relief valve 306 is fluidly connected to the H2 power unit 106 via a vaporization fuel line 308. The H2 power unit 106 consumes the gaseous hydrogen 304 received from the vaporization fuel line 308 to prevent waste of hydrogen fuel from a vaporization condition.

[0026] During normal operation of the work machine 100, the H2 storage tank 110 provides liquid hydrogen 300 to the H2 power unit 106 via a liquid fuel line 310. The liquid fuel line 310 may be fluidly or hydraulically connected to the H2 power unit 106 to consume the liquid hydrogen 300 stored in the H2 storage tank 110.

[0027] If the pressure within the H2 storage tank 110 exceeds the emergency pressure release threshold, the H2 storage tank 110 may also have a second pressure relief valve 312 for emergency pressure release of the gaseous hydrogen 304 to the atmosphere. The vaporized fuel line 308 may optionally include a hydrogen condenser 314 to liquefy the gaseous hydrogen 304 before the gaseous hydrogen 304 is provided to the H2 power unit 106, for a higher density energy form of hydrogen and more efficient consumption of the vaporized gaseous hydrogen 304. For the case where the liquid hydrogen 300 leaves the H2 storage tank 110 via the liquid fuel line 310, a vaporizer 318 may also be provided on the H2 storage tank 110. In addition, the vaporizer 318 may be used to warm the gas from the near-cryogenic temperature within the H2 storage tank 110 and be provided on the vaporized fuel line 304.

[0028] The annular space 204 may contain insulating material 316 between the shell 202 and the high pressure vessel 200. Providing insulating material 316 in the annular space 204 reduces heat transfer and evaporation of cryogenic hydrogen. The insulation in the annular space 204 may include multiple layers of high performance insulation materials, including aerogel felts and vacuum sealing panels, or vacuum insulation configured in double wall H2 storage tanks to minimize heat transfer and improve preservation, as is generally known in the art.

[0029] When the working machine 100 is inactive or in a sleep state, the liquid hydrogen 300 may change state to gaseous hydrogen 304 in large quantities. The boil-off pressure relief valve 306 may be configured to discharge the gaseous hydrogen 304 to the boil-off fuel line 308 for consumption by the H2 power unit 106 to avoid wasting the gaseous hydrogen 304 when the working machine 100 is inactive, in a sleep mode, or shut down. When the working machine 100 is inactive, the H2 power unit 106 may be activated when a boil-off pressure threshold for consuming the gaseous hydrogen 304 provided via the boil-off fuel line 308 is exceeded to generate electrical energy by discharging the gaseous hydrogen 304 via the second pressure relief valve 312 without wasting potential electrical energy.

[0030] Reference now Figure 4 , a schematic diagram of an H2 fuel system 400 according to one embodiment of the present invention is shown. The H2 fuel system 400 may include an H2 power unit 106, an H2 storage tank 110, a power distribution unit 402 ("PDU 402"), and a controller 404. The H2 power unit 106 may be hydraulically connected to the H2 storage tank 110 for consuming liquid hydrogen 300 and gaseous hydrogen 304. The H2 power unit 106 converts hydrogen fuel into electrical energy and provides the electrical energy to the PDU 402.

[0031] The PDU 402 is also connected to the battery 108 and the machine operating system 406. There may be a first power converter 408 that converts the electrical energy to a desired form or specific load before providing the electrical energy to the PDU 402 and / or a specific operating system in the work machine 100. The power generated by the H2 power unit 106 may be transmitted to the power distribution unit 402 and may be used to recharge the battery 108, power the machine operating system 406 and / or power other systems of the work machine 100. The power converter 408 may be a high voltage to low voltage power converter. Additionally, the low voltage setting may be set to the system voltage, typically 12V or 24V, as desired.

[0032] The PDU 402 may be a basic, metered, monitored, switched, ATS, frame mounted, modular, or high density power distribution unit, selected for specific power distribution and management needs in various applications. The PDU 402 may include features such as multiple outlets, metering capabilities, remote monitoring and control, redundancy, rack compatibility, customization, and high outlet density to suit different equipment and environmental requirements. The machine operating systems 406 may each be powered by a plurality of system batteries (not shown), which may be rechargeable batteries, as is generally known in the art.

[0033] The controller 404 in the work machine 100 can control a machine operating system 406 associated with the work machine 100. The machine operating system 406 can be one of many operating systems present in the work machine 100, such as an ignition system, a fuel injection system, a fuel delivery system, a transmission, a throttle system, a power system, a braking system, a cooling system, a navigation system, a lighting system, an alarm system, a battery system, and / or an engine or other propulsion system, as generally known in the art. These systems may also include one or more hydraulic, mechanical, electronic, and software-based components, wherein the controller 404 can communicate with and control these components, as is known in the art. The controller 404 may be embodied as a single microprocessor or multiple microprocessors including devices for controlling various operations in the work machine 100. The microprocessor may be configured to perform the functions of the controller 404. The controller 404 may be embodied as a general-purpose machine microprocessor capable of controlling a variety of machine functions. The controller 404 may include a memory, an auxiliary storage device, a processor, and any other components for running applications and storing a collection of received data and signals.

[0034] The H2 storage tank 110 may include a fuel level sensor 410 for measuring the amount of hydrogen fuel remaining in the H2 storage tank 110, a tank pressure sensor 412 for measuring the pressure in the H2 storage tank 110, and a tank temperature sensor 414 for monitoring the temperature in the H2 storage tank 110. The fuel level sensor 410 may be a fuel float sensor, which may utilize a floating device or float that moves up and down with the level of liquid fuel in the H2 storage tank 110. As the fuel level sensor 410 moves, it may transmit a fuel level signal to the controller 404 indicating the fuel level of liquid H2 remaining over time.

[0035] As is known in the art, the H2 storage tank 110 may be connected to an active cooling system 416, an emergency shutdown system 418, and / or a leak detector system 420. The active cooling system 416 may employ active cooling techniques to maintain the cryogenic temperatures required for liquid hydrogen storage, as is known in the art. The emergency shutdown system 418 may automatically isolate the cryogenic fluid supply in the H2 storage tank 110 and may activate a fire extinguishing system upon detection of a fire or abnormal operating condition, as is known in the art.

[0036] The controller 404 may be connected to an off-machine network 422. The controller 404 and the off-machine network 422 may be in communication with each other, whereby a remote controller 424 may be connected to the off-machine network 422 to remotely control the machine operating system 406. The remote controller 424 may be a computer, laptop, mobile phone, tablet computer, etc., which may access the off-machine network 422 via a website, URL, app, etc., as is known in the art. The remote controller 424 may be used to communicate with the controller 404 via the off-machine network 422 to control, activate, or deactivate the machine operating system 406 within the work machine 100. The controller 404 may also have a digital interface that allows integration with various monitoring and control systems in the work machine 100, and may also be operated via the remote controller 424.

[0037] External device 426 may be connected to work machine 100, such as a vehicle, another work machine, an electrical grid, or any device that requires charging. The electrical energy generated by H2 power unit 106 may be used to charge one or more batteries associated with other machines 428, to charge a battery-based energy storage system 430, or to power electrical grid 432.

[0038] Reference now Figure 5 , a schematic diagram of a second H2 fuel system 500 according to another embodiment of the present invention is shown. The second H2 fuel system 500 can provide the H2 power unit 106 as a fuel cell 502, which converts hydrogen fuel into electrical energy and supplies the electrical energy to the PDU 402. The fuel cell 502 can be hydraulically connected to the H2 storage tank 110 for consuming liquid hydrogen 300 through the liquid fuel line 310 and gaseous hydrogen 304 through the vaporized fuel line 308 to generate electrical energy. The electrical energy is then distributed to the second power converter 504 to convert the electrical energy into a desired form or specific load before transmitting the electrical energy to the PDU 402 for energy distribution in the work machine 100.

[0039] Fuel cell 502 can be one or more electromechanical devices that generate electricity through electrochemical processes using hydrogen as a fuel source, as is known in the art. Fuel cell 502 can include multiple electrochemical cells that directly convert chemical energy stored as fuel in liquid hydrogen 300 and gaseous hydrogen 304 into electrical energy, with water as the main byproduct. Fuel cell 502 can be composed of an anode, a cathode, an electrolyte, and a catalyst, as is generally known in the art. The anode is where hydrogen is supplied to the fuel cell. At the anode, hydrogen molecules split into protons (H+) and electrons (e-). The cathode is where oxygen in the air combines with electrons and protons to form water, and the electrons and protons pass through an external circuit. The electrolyte is a special material that allows ions and / or charged particles to migrate while preventing hydrogen and oxygen from mixing. Protons can move through the electrolyte, while electrons flow through the external circuit, generating an electric current. Catalysts are provided to promote the electrochemical reactions that occur at the anode and cathode. Platinum can be used as a catalyst in a hydrogen fuel cell. When gaseous hydrogen 304 is supplied to the anode of fuel cell 502 via vaporized fuel line 308, it undergoes oxidation, releasing electrons. The protons produced in the process travel through the electrolyte to the cathode, while the electrons take an external path, producing an electrical energy current that can be used to power various devices. At the cathode, oxygen from the air combines with the protons and electrons to form water as a byproduct. The fuel cell 502 can be a 250-500V fuel cell.

[0040] The PDU 402 may then distribute the electrical energy to the battery 108 and the machine operating system 406. Based on the battery voltage versus the bus voltage, a third power converter 506 may be provided between the battery 108 and the PDU 402. Based on the bus voltage versus the BTMS voltage (battery thermal management system), a fourth power converter 508 may be provided between the PDU 402 and electrically connected to the cab heater 510 and the HVAC compressor 512.

[0041] The first, second, third and fourth power converters 408, 504, 506, 508 may be electromechanical devices, such as AC to DC converters, DC to DC converters, etc., which convert a current source (e.g., direct current (DC)) from one voltage level to another voltage level, as is generally known in the art. The first, second, third and fourth power converters 408, 504, 506, 508 may be electromechanical power converters, such as circuits that change electrical energy from one form of electrical energy to a desired form of electrical energy optimized for a specific load, and may be used to increase or decrease the amplitude of an input voltage, reverse polarity, or generate a number of output voltages having the same polarity, a different polarity, or a mixed polarity as the input. The power level may range from a low level of a small battery to a very high level of high voltage power transmission. The first, second, third and fourth power converters 408, 504, 506, 508 may convert the received current to at least 24V. In one embodiment, each of the first, second, third and fourth power converters 408, 504, 506, 508 may be a DC to DC converter.

[0042] The PDU 402 may also distribute electrical energy to an inverter 514 to provide electrical energy to a traction motor 516 and an implement motor 518 in the work machine 100. The PDU 402 may also distribute electrical energy to a machine operating system 406, which may include a lead-acid battery 520, a cooling fan 522, a water pump 524, an oil pump 526, a machine engine control module 528, a fuel cell 530 with a maximum of 100A, and a battery thermal management system 532, each with a dedicated battery.

[0043] A battery charging system 534 may be provided in the H2 fuel system 500 electrically connected to the PDU 402. The battery charging system 534 may include a charging port 536 and an onboard battery charger 538 to condition the battery 108 during long sleep states and extreme temperatures. Long sleep states typically occur between jobs, when there is a significant risk of any stored cryogenic hydrogen in the work machine 100 being vaporized due to exhaust, thereby causing waste. Additionally, the extra charge from the battery charging system 534 may be used for cell conditioning / balancing of the battery 108, as is generally known in the battery art.

[0044] Reference now Figure 6, a schematic diagram of a third H2 fuel system 600 according to another embodiment of the present invention is shown. The third H2 fuel system 600 may provide an H2 power unit 106 as a hydrogen internal combustion engine 602 ("H2 ICE 602"), which converts hydrogen fuel into electrical energy and provides the electrical energy to the PDU 402. The H2 ICE 602 may be hydraulically connected to the H2 storage tank 110 for consuming liquid hydrogen 300 via a liquid fuel line 310 and consuming gaseous hydrogen 304 via a vaporized fuel line 308 to generate electricity supplied to a generator 604. The generator 604 may be connected to a second inverter 606, which may be further connected to the PDU 402. The second inverter 606 may be connected to a traction motor 608 of the working machine 100. The generator 604 may include or be connected to a hydrogen pump 610.

[0045] The H2 ICE 602 may include a cylinder into which gaseous hydrogen 304 may be injected along with air. The hydrogen-air mixture may be ignited by a spark plug, causing a controlled explosion that drives a piston and produces mechanical energy, as is generally known in the art. The mechanical energy may then be converted into useful work, such as by turning a crankshaft. The exhaust from the H2 ICE contains water vapor as a primary emission.

[0046] The H2 fuel system 400, the second H2 fuel system 500, and the third H2 fuel system 600 may be active while the work machine 100 is inactive or inoperable to avoid waste of boiling gaseous hydrogen 304 into the atmosphere. When the tank pressure sensor 412 detects a pressure exceeding the boil-off pressure threshold, the H2 power unit 106 may be activated by the controller 404 while the work machine 100 is inactive, such that the gaseous hydrogen 304 is transferred to the H2 power unit 106 for consumption to generate electrical energy and to avoid waste of hydrogen fuel.

[0047] Industrial Applicability

[0048] In operation, the present invention may be applied to many industries, including but not limited to the automotive, construction, earthmoving, mining and agricultural industries. Specifically, the systems, machines and methods of the present invention may be used in hydrogen energy systems of other working machines, including but not limited to excavators, backhoes, rope shovels, skid loaders, wheel loaders, tractors, automobiles, trucks, cars and similar machines. Although the foregoing detailed description is made with specific reference to excavators, it should be understood that its teachings may also be applied to other working machines.

[0049] Reference now Figure 7, shows an H2 fuel saving operation 700 of the H2 fuel system 400 according to one embodiment of the present invention. The H2 fuel saving operation 700 may also be used with the second H2 fuel system 500 and the third H2 fuel system 600. In operation 702, the work machine 100 may be in a sleep state or an inactive state. In operation 704, the controller 404 determines whether the pressure in the H2 storage tank 110 is lower than the boil-off pressure threshold in the H2 storage tank 110 based on the signal received from the tank pressure sensor 412. In operation 704, the tank pressure sensor 412 may be in communication with the controller 404 and the boil-off pressure relief valve 306 to release or discharge the gaseous hydrogen 304 to the H2 power unit 106 when the pressure exceeds the boil-off pressure threshold.

[0050] In operation 706, if the pressure is below the target of the vaporization pressure threshold, the work machine 100 may remain in the sleep state or shut down. In operation 708, if the pressure is above the vaporization pressure threshold in operation 704, the controller 404 may determine whether the remaining power in the battery 108 is below the battery threshold. In operation 710, when the battery 108 or multiple system batteries of the machine operating system 406 is below the battery threshold, the H2 power unit 106 begins charging the battery 108 or multiple system batteries of the machine operating system 406. The battery threshold may be a maximum battery capacity.

[0051] When the battery 108 is above the battery threshold, in operation 712, the controller 404 determines whether the work machine 100 is further connected to any external device 426 that requires battery recharging. If there is an external device 426 electrically connected to the work machine 100, then in operation 714, the controller 404 determines whether the external load of the external device 426 is below the external load target. If the external load is below the load target, the H2 power unit 106 begins charging the battery 108 by consuming liquid hydrogen 300 and / or gaseous hydrogen 304 in operation 710. If the external load of the external device 426 is above the external load target, the work machine 100 is placed in a sleep state or shut down, as in operation 706. The external device 426 can be connected to the work machine 100, such as a vehicle, another work machine, an electrical grid, or any device that requires charging. The generated electrical energy may be used to power one or more machine operating systems 406 of the work machine 100, to recharge the battery 108 of the work machine 100, to charge one or more batteries 428 associated with other machines, to charge a battery-based energy storage system 430, or to power an electrical grid 432. The generated electrical energy may recharge the internal high-voltage and low-voltage batteries of other machines 428, provide a DC power connection to external devices 426, such as recharging batteries of a light tower, car, truck, and be used to power components of other machines 428 that require power. The generated electrical energy may provide AC power to the electrical grid 432, which may require additional hardware components to be located inside or outside the work machine 100, as is known in the art.

[0052] In operation 712, if the work machine 100 is not electrically connected to an external device, the gaseous hydrogen 304 may be released or vented to the atmosphere via the second pressure relief valve 312 when the pressure exceeds the emergency pressure threshold to avoid an explosion in operation 716. The gaseous hydrogen 304 may be vented to the atmosphere only when the battery 108 and the plurality of system batteries are at maximum capacity, the work machine 100 is not connected to any external device or the external device is at maximum battery capacity, and / or the pressure is below the emergency pressure threshold to allow the gaseous hydrogen 304 to be stored for future use.

[0053] Reference now Figure 8 , shows a method 800 for storing hydrogen in an H2 fuel system 400 according to one embodiment of the present invention. In step 802, an H2 storage tank 110 is provided in fluid connection with an H2 power unit 106. The H2 power unit 106 can be selected from one of a fuel cell and a hydrogen internal combustion engine. The H2 storage tank 110 containing liquid hydrogen 300 and / or gaseous hydrogen 304 is provided, or it can be provided as cryogenic compressed hydrogen.

[0054] In step 804, the boil-off pressure relief valve 306 is installed in fluid communication with the H2 storage tank 110 and is configured to discharge the gaseous hydrogen 304 to the boil-off fuel line 308 for releasing the pressure within the H2 storage tank 110. In step 806, the gaseous hydrogen 304 is transmitted to the H2 power unit 106 via the boil-off fuel line 308 for hydrogen fuel consumption and generation of electrical energy by the H2 power unit 106.

[0055] When the batteries for the machine operating system 406 have load capacity to be charged, the electrical energy generated from the gaseous hydrogen 304 may be transmitted to recharge the batteries for the machine operating system 406, such as the lead-acid battery 520, the cooling fan 522, the water pump 524, the oil pump 526, the machine engine control module 528, the fuel cell with a maximum of 100A, and the battery thermal management system 532. If all batteries of the machine operating system 406 are at maximum capacity, the gaseous hydrogen 304 may alternatively be vented to the atmosphere via the second pressure relief valve 312 if the pressure exceeds the emergency pressure threshold.

[0056] As can be seen from the foregoing, the technology disclosed herein has industrial applicability in a variety of settings, such as, but not limited to, the automotive, agricultural, construction, energy production and mining industries, which utilize work machines such as automobiles, cars, trucks, generators, excavators, backhoes, rope shovels, skid steers, wheel loaders, tractors and similar work machines having power packs or engines that use hydrogen as a fuel.

Claims

1. A hydrogen fuel system for a working machine, comprising: a hydrogen storage tank containing hydrogen, the hydrogen being at least one of liquid hydrogen or gaseous hydrogen; a hydrogen power unit configured to consume hydrogen from the hydrogen storage tank, the hydrogen power unit comprising at least one of a plurality of fuels or a hydrogen combustion engine; a boil-off pressure relief valve in fluid communication with the hydrogen storage tank; and A tank pressure sensor is in communication with the boil-off pressure relief valve, the boil-off pressure relief valve being configured to discharge the gaseous hydrogen to a boil-off fuel line fluidly connected to the hydrogen power unit when the tank pressure sensor detects a first pressure within the hydrogen storage tank exceeding a boil-off pressure threshold.

2. The hydrogen fuel system of claim 1 , wherein the vaporized fuel line is configured to transmit the gaseous hydrogen to the hydrogen power unit for consumption of the gaseous hydrogen to generate electrical energy for at least one of: powering one or more machine operating systems of the work machine, recharging a battery of the work machine, charging one or more batteries associated with other machines, charging a battery-based energy storage system, or powering a power grid.

3. The hydrogen fuel system according to claim 2, wherein the electrical energy is a first electrical energy, further comprising: a power converter connected to the hydrogen power unit, the power converter being configured to convert the electrical energy into second electrical energy; as well as A power distribution unit is connected to the power converter, wherein the power distribution unit transmits electric power to the one or more machine operating systems based on the second electrical energy.

4. The hydrogen fuel system according to claim 1, wherein the hydrogen storage tank comprises an inner tank containing the hydrogen, an outer tank surrounding the inner tank and forming an annular space between the inner tank and the outer tank, and at least one of the following: a second pressure relief valve located on the hydrogen storage tank, the second pressure relief valve being used to discharge a portion of the gaseous hydrogen to the atmosphere when the tank pressure sensor detects that a second pressure within the hydrogen storage tank exceeds an emergency pressure threshold that is greater than the boil-off pressure threshold; The inner tank is made of a material selected from high-strength steel, high-strength carbon fiber and high-strength aluminum alloy; The outer tank is made of a material selected from high-strength steel, high-strength carbon fiber and high-strength aluminum alloy; Insulation material disposed in the annular space and being one of a multi-layer high performance insulation material, an aerogel felt, and a vacuum sealed panel; a level sensor positioned within the inner tank and configured to monitor and provide real-time feedback regarding the volume of cryogenic fluid stored within the inner tank; an active cooling device integrated with the outer tank and configured to extract heat from the hydrogen storage tank and maintain the temperature of the inner tank at a cryogenic level to avoid excess gaseous hydrogen; or An integrated safety system, which includes temperature sensors, leak detectors and an emergency shut-off mechanism, is configured to ensure safe operation.

5. A working machine comprising: frame; ground engaging elements supporting the frame; a battery supported by the frame; a plurality of machine operating systems associated with a plurality of system batteries; The hydrogen fuel system according to claim 5, further comprising: a hydrogen storage tank mounted in the frame; a hydrogen power unit mounted in the frame; Tank pressure sensor in hydrogen storage tank; a controller in communication with the tank pressure sensor and the plurality of machine operating systems; and a boil-off pressure relief valve in fluid communication with the hydrogen storage tank and in electrical communication with the tank pressure sensor, the boil-off pressure relief valve being configured to discharge the gaseous hydrogen to a boil-off fuel line fluidly connected to the hydrogen power unit when the tank pressure sensor detects that the pressure within the hydrogen storage tank exceeds a boil-off pressure threshold, wherein the boil-off fuel line is configured to transmit the gaseous hydrogen to the hydrogen power unit for consumption of the gaseous hydrogen to generate electrical energy for charging the battery or at least one of the plurality of system batteries.

6. The working machine according to claim 5, wherein the hydrogen fuel system further comprises: a liquid fuel line fluidly connected to the hydrogen storage tank and the hydrogen power unit to transport the liquid hydrogen for fuel consumption by the hydrogen power unit; a power converter connected to the hydrogen power unit, the power converter being configured to convert the electrical energy into second electrical energy; as well as A power distribution unit is connected to the hydrogen power unit, wherein the power distribution unit transfers power from the second electrical energy source to the plurality of system batteries of the plurality of machine operating systems.

7. The work machine according to claim 6, wherein: The gaseous hydrogen is discharged to the plurality of fuel cells via the vaporization pressure relief valve, the plurality of fuel cells consume the gaseous hydrogen to generate electrical energy, the electrical energy is subsequently converted by the power converter into the second electrical energy, and the second electrical energy is delivered for at least one of: powering one or more machine operating systems of a working machine, recharging a battery of a working machine, charging one or more batteries associated with other machines, charging a battery-based energy storage system, or powering a power grid.

8. The work machine of claim 7, wherein the work machine is one of an excavator, a truck, a backhoe, a rope shovel, a skid steer loader, a wheel loader, a tractor, or a generator.

9. The work machine of claim 8, wherein a first machine operating system of the plurality of machine operating systems is one selected from the group consisting of an ignition system, a fuel injection system, an oil delivery system, a transmission, a throttle system, a power system, a brake system, a cooling system, a navigation system, a lighting system, an alarm system, a battery system, a lead-acid battery, a cooling fan, a water pump, an oil pump, a machine engine control module, a fuel cell, and a battery thermal management system.

10. A method for preserving hydrogen fuel in a hydrogen fuel system for a working machine, the method comprising: providing a hydrogen storage tank fluidly connected to a hydrogen power unit, the hydrogen power unit comprising at least one of a fuel cell or a hydrogen internal combustion engine, the hydrogen storage tank containing at least one of liquid hydrogen or gaseous hydrogen, wherein a boil-off pressure relief valve is in communication with the hydrogen storage tank and is configured to discharge gaseous hydrogen to a boil-off fuel line, the gaseous hydrogen being used to release pressure within the hydrogen storage tank, the boil-off fuel line being in fluid communication between the boil-off pressure relief valve and the hydrogen power unit; and When the working machine is in an inactive state, the gaseous hydrogen is transmitted to the hydrogen power unit via the vaporized fuel line for hydrogen fuel consumption and electricity production by the hydrogen power unit.

11. The method according to claim 10, further comprising: monitoring pressure in the hydrogen storage tank via a tank pressure sensor in the hydrogen storage tank in communication with the controller and the vapor pressure relief valve; When the controller receives a pressure signal from the tank pressure sensor indicating that the pressure in the hydrogen storage tank exceeds a boil-off pressure threshold, discharging the gaseous hydrogen through the boil-off pressure relief valve; consuming the gaseous hydrogen via the hydrogen power unit to generate electrical energy; transmitting said electrical energy from said hydrogen power unit to a power converter; converting the form of the electrical energy into second electrical energy via the power converter; and The second electrical energy is transmitted to a power distribution unit in communication with a plurality of machine operating systems of the work machine for at least one of: charging one or more batteries in the work machine or powering the plurality of machine operating systems.

12. The method according to claim 11, wherein the hydrogen storage tank further comprises an inner tank containing the hydrogen, and an outer tank surrounding the inner tank and forming an annular space between the inner tank and the outer tank, the method further comprising: integrating a cryogenic cooling device with the outer tank, the cryogenic cooling device being configured to extract heat from the hydrogen storage tank and maintain the temperature of the inner tank at a cryogenic level to mitigate vaporization of the cryogenic fluid; installing a second pressure relief valve on the hydrogen storage tank, the second pressure relief valve being used to discharge gaseous hydrogen into the atmosphere when the tank pressure sensor detects that the pressure in the hydrogen storage tank exceeds an emergency pressure threshold greater than the vaporization pressure threshold; Incorporating within the annular space an insulation system comprising high performance insulation material, the insulation system being designed to minimize heat transfer into the inner tank and mitigate cryogenic fluid boil-off; Implementing an integrated safety system that includes temperature sensors, leak detectors, and emergency shutoff mechanisms to ensure safe operation of the hydrogen fuel system by automatically isolating the hydrogen and activating the fire suppression system when a fire or abnormal operating condition is detected; configuring the work machine to be one of an excavator, a truck, a backhoe, a rope shovel, a skid steer loader, a wheel loader, a tractor, or a generator; and The plurality of machine operating systems are selected from the group consisting of an ignition system, a fuel injection system, a fuel delivery system, a transmission, a throttle system, a power system, a brake system, a cooling system, a navigation system, a lighting system, an alarm system, a battery system, a lead-acid battery, a cooling fan, a water pump, an oil pump, a machine engine control module, a fuel cell, and a battery thermal management system.

Images