A multi-power system based on hydrogen-ammonia engine and ammonia fuel cell

Abstract

The present invention discloses a multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell, comprising: a liquid ammonia gasification device; an ammonia tank, an air inlet of which is connected to the air outlet of the liquid ammonia gasification device; an ammonia online cracking hydrogen production device, an air inlet of which is connected to the air outlet of the liquid ammonia gasification device; an air inlet of a gas separation device is connected to the air outlet of the ammonia online cracking hydrogen production device; an ammonia inlet of the hydrogen-ammonia engine is connected to the air outlet of the ammonia tank, and a hydrogen inlet is connected to the hydrogen outlet; a transmission device, an input end of which is selectively connected to or separated from the power output end of the hydrogen-ammonia engine; an ammonia solid oxide fuel cell, an air inlet of which is connected to the air outlet of the ammonia tank; a power battery, an input end of which is connected to the output end of the ammonia solid oxide fuel cell; a motor, a power input end of which is connected to the output end of the power battery and / or the output end of the ammonia solid oxide fuel cell; and a torque coupler, an input end of which is simultaneously connected to the output end of the motor and the output end of the transmission device.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobile power systems, and in particular relates to a multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell. Background Art

[0002] In 2020, carbon emissions from the transportation sector accounted for approximately 10% of my country's annual carbon emissions, with urban transportation emissions becoming the fastest-growing sector. In this context, the development of low-carbon vehicles is a key strategic imperative for green development in my country and ultimately in human society. Therefore, the use of zero-carbon fuels such as ammonia and hydrogen is currently one of the core technologies of greatest interest to the automotive industry.

[0003] Pure hydrogen faces high costs due to difficulties in storage, transportation, and refueling. Ammonia, as a hydrogen carrier, suffers from slow combustion, high ignition energy, and a narrow flammability range. Fuel cells offer high energy efficiency, but their dynamic response is slow, making them unable to meet the power demands of extreme operating conditions such as frequent starts and stops, rapid acceleration and deceleration, and hill climbing. Summary of the Invention

[0004] The purpose of the present invention is to address the defects of the existing technology and provide a multi-power system of a hydrogen-ammonia engine and an ammonia fuel cell. The hybrid structure of the hydrogen-ammonia engine system and the ammonia solid oxide fuel cell system is adopted, which can achieve efficient and stable operation of the power system under different working conditions.

[0005] The technical solution provided by the present invention is:

[0006] A multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell, comprising:

[0007] Liquid ammonia tank;

[0008] a liquid ammonia gasification device, the liquid inlet of which is connected to the liquid outlet of the liquid ammonia tank;

[0009] an ammonia tank, the air inlet of which is connected to the air outlet of the liquid ammonia gasification device;

[0010] an ammonia online cracking hydrogen production device, the gas inlet of which is connected to the gas outlet of the liquid ammonia gasification device;

[0011] A gas separation device is provided with an air inlet, an ammonia outlet, a hydrogen outlet and a nitrogen outlet; the air inlet of the gas separation device is connected to the air outlet of the ammonia online cracking hydrogen production device;

[0012] Wherein, the ammonia outlet is connected to the air inlet of the ammonia tank;

[0013] A hydrogen-ammonia engine having an ammonia inlet and a hydrogen inlet, wherein the ammonia inlet is connected to the gas outlet of the ammonia tank, and the hydrogen inlet is connected to the hydrogen outlet;

[0014] a transmission device, the input end of which is selectively connected to or disconnected from the power output end of the hydrogen-ammonia engine;

[0015] an ammonia solid oxide fuel cell, the air inlet of which is in communication with the air outlet of the ammonia tank;

[0016] a power battery, the input end of which is connected to the power output end of the ammonia solid oxide fuel cell;

[0017] a motor, the power input end of which is connected to the output end of the power battery and / or the power output end of the ammonia solid oxide fuel cell;

[0018] The power input end of the torque coupler is connected to the power output end of the motor and the power output end of the transmission device at the same time, and the power output end of the torque coupler transmits power to the vehicle drive system.

[0019] Preferably, the multi-power system based on the hydrogen-ammonia engine and the ammonia fuel cell further comprises:

[0020] An ammonia SCR post-treatment device has an inlet that is simultaneously connected to the exhaust outlet of the hydrogen-ammonia engine and the gas outlet of the ammonia tank.

[0021] Preferably, the multi-power system based on the hydrogen-ammonia engine and the ammonia fuel cell further comprises:

[0022] A waste heat recovery device, the inlet of which is connected to the outlet of the ammonia SCR post-treatment device, and the outlet of the waste heat recovery device is connected to the ammonia online cracking hydrogen production device, for providing heat to the ammonia online cracking hydrogen production device.

[0023] Preferably, the output end of the power battery is connected to the ammonia online cracking hydrogen production device.

[0024] Preferably, the multi-power system based on the hydrogen-ammonia engine and the ammonia fuel cell further comprises:

[0025] A DC / DC inverter has one end connected to the power output end of the ammonia solid oxide fuel cell, and the other end connected to both the power battery and the motor.

[0026] Preferably, a clutch is provided between the input end of the transmission device and the power output end of the hydrogen-ammonia engine.

[0027] Preferably, the multi-power system based on the hydrogen-ammonia engine and the ammonia fuel cell further comprises:

[0028] a transmission connected to a power output end of the torque coupler; and

[0029] A final reducer is connected to the transmission.

[0030] Preferably, the nitrogen outlet is in communication with an external environment of the multi-element power system.

[0031] Preferably, the injection mode of the hydrogen-ammonia engine is direct injection or compound injection.

[0032] The beneficial effects of the present invention are:

[0033] The multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell provided by the present invention uses hydrogen as a combustion aid for ammonia and employs an ammonia solid oxide fuel cell. Combining the advantages of the hydrogen-ammonia engine and the ammonia solid oxide fuel cell, the engine is used as the main power source in operating conditions such as start-stop, rapid acceleration and deceleration, low-speed driving, and climbing. Under normal operating conditions, the fuel cell system is switched as the main power source, thereby achieving high-efficiency, stable operation and near-zero emissions of the entire vehicle under different operating conditions.

[0034] The multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell provided by the present invention uses ammonia to produce hydrogen through online cracking, thus avoiding problems such as hydrogen storage, transportation, and refueling; and uses ammonia to catalytically reduce nitrogen oxides in the engine and in the after-treatment system, thus avoiding the crystallization, blockage, and in-use compliance problems caused by the use of urea in traditional automotive SCR devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the overall structure of the multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell according to the present invention.

[0036] Figure 2 Schematic diagram of the control process of the multi-power system based on hydrogen-ammonia engine and ammonia fuel cell according to the present invention. DETAILED DESCRIPTION

[0037] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0038] like Figure 1 As shown, the present invention provides a multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell, which mainly includes: a liquid ammonia tank, a liquid ammonia gasification device, an ammonia tank, an ammonia online cracking hydrogen production device, a gas separation device, a hydrogen-ammonia engine, an ammonia SCR post-treatment device, an ammonia solid oxide fuel cell, a waste heat recovery device, a power battery, a DC / DC inverter, a motor, a clutch, a transmission device, a torque coupler, a transmission and a final reducer.

[0039] The liquid ammonia tank is used to store liquid ammonia. The liquid inlet of the liquid ammonia gasification device is connected to the liquid outlet of the liquid ammonia tank. The liquid ammonia gasification device converts liquid ammonia into ammonia gas.

[0040] The air inlet of the ammonia online cracking hydrogen production device is connected to the air outlet of the liquid ammonia gasification device, and is used to decompose the ammonia discharged from the liquid ammonia gasification device. The gas discharged by the ammonia online cracking hydrogen production device is a mixed gas of ammonia, hydrogen and nitrogen.

[0041] The gas separation device has an inlet and three outlets, and the three outlets of the gas separation device are: an ammonia outlet, a hydrogen outlet, and a nitrogen outlet. The air inlet (inlet) of the gas separation device is connected to the air outlet of the ammonia online cracking hydrogen production device. After the mixed gas discharged from the ammonia online cracking hydrogen production device enters the gas separation device through the air inlet of the gas separation device, it is separated into ammonia, hydrogen, and nitrogen in the gas separation device and discharged through the ammonia outlet, hydrogen outlet, and nitrogen outlet, respectively. Among them, the nitrogen outlet is connected to the external environment of the multi-power system, and the nitrogen separated in the gas separation device is discharged into the air through the nitrogen outlet.

[0042] In this embodiment, the ammonia tank has two inlets (a first air inlet and a second air inlet) and three outlets (a first air outlet, a second air outlet and a third air outlet). The first air inlet (inlet) is connected to the air outlet of the liquid ammonia gasification device, and the second air inlet (inlet) is connected to the ammonia outlet of the gas separation device. The gas separation device pressurizes the separated ammonia and sends it into the ammonia tank.

[0043] The hydrogen-ammonia engine has an ammonia inlet and a hydrogen inlet, wherein the ammonia inlet is connected to the first outlet of the ammonia tank, and the hydrogen inlet is connected to the hydrogen outlet of the gas separation device. The injection method of the hydrogen-ammonia engine can be direct injection or combined injection.

[0044] The input end of the transmission device selectively connects or disconnects with the power output end of the hydrogen-ammonia engine. In this embodiment, a clutch is provided between the input end of the transmission device and the power output end of the hydrogen-ammonia engine, and the clutch connects or disconnects the input end of the transmission device and the power output end of the hydrogen-ammonia engine.

[0045] The air inlet of the ammonia solid oxide fuel cell is communicated with the second air outlet of the ammonia tank, and the ammonia solid oxide fuel cell generates electrical energy by utilizing ammonia.

[0046] The power output of the ammonia solid oxide fuel cell is connected to one end of a DC / DC inverter, the other end of which is connected to both the power battery and the motor. The electricity generated by the ammonia solid oxide fuel cell is stored in the power battery as direct current through the DC / DC inverter or fed into the motor, which then operates by outputting direct current through the DC / DC inverter. The power input of the motor is connected to the output of the power battery, which in turn is connected to the online ammonia cracking hydrogen production device, providing power to the device.

[0047] The torque coupler has a power input connected to both the motor's power output and the transmission's power output. The torque coupler's power output is connected to the transmission, which in turn is connected to the final drive. The transmission and motor are connected in parallel, supplying energy to the torque coupler. The transmission and final drive then match the powertrain's torque to the vehicle's operating requirements.

[0048] In this embodiment, the ammonia SCR post-treatment device has two inlets and one outlet. The first inlet is connected to the exhaust outlet of the hydrogen-ammonia engine, and the second inlet is connected to the third outlet of the ammonia tank. Exhaust gas containing nitrogen oxides generated by combustion in the hydrogen-ammonia engine is fed into the ammonia SCR post-treatment device. Ammonia provided by the ammonia tank reduces nitrogen oxides in the exhaust gas to produce nitrogen and water.

[0049] The outlet of the ammonia SCR post-treatment unit is connected to the inlet of the waste heat recovery unit. The outlet of the waste heat recovery unit is connected to the ammonia online cracking hydrogen production unit, which uses the waste heat generated by the engine and fuel cell to heat the ammonia.

[0050] The following is a further description of the multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell provided by the present invention in conjunction with a specific workflow:

[0051] Liquid ammonia in the liquid ammonia tank is converted into ammonia gas through a liquid ammonia vaporization unit. Part of the ammonia gas enters the ammonia tank, while the remaining part enters the online ammonia cracking hydrogen production unit. The online ammonia cracking hydrogen production unit breaks the ammonia gas into nitrogen and hydrogen. The resulting mixed gas enters a gas separation unit, where it separates the mixed gas into nitrogen, ammonia, and hydrogen. The ammonia gas discharged from the gas separation unit is pressurized and enters the ammonia tank. The hydrogen enters the hydrogen-ammonia engine, while the nitrogen is exhausted to the atmosphere. Some of the ammonia gas in the ammonia tank enters the hydrogen-ammonia engine through the first outlet, where it undergoes hydrogen-assisted combustion. The combustion products enter the ammonia SCR post-treatment unit. Some of the ammonia gas in the ammonia tank enters the SCR post-treatment unit through the third outlet, where it reduces nitrogen oxides in the combustion products. The gas discharged from the SCR post-treatment unit enters the inlet of the waste heat recovery unit. The mechanical energy generated by the hydrogen-ammonia engine is transmitted to the transmission via a clutch. Ammonia gas from the ammonia tank enters the ammonia solid oxide fuel cell through the tank's second outlet. The generated electricity is stored in the power battery as direct current through a DC / DC inverter or fed into the motor. The power battery simultaneously supplies power to the motor and ammonia cracker. The transmission and motor, connected in parallel, feed energy to the torque coupler, which then passes through the transmission and final drive to match the powertrain's torque to the vehicle's operating requirements.

[0052] In this embodiment, the hydrogen-ammonia engine uses direct injection, with hydrogen fuel supporting the combustion of ammonia fuel to provide power. The fuel cell utilizes an ammonia solid oxide fuel cell. Ammonia enters the anode and decomposes into nitrogen and hydrogen. The hydrogen protons then pass through the electrolyte layer and react with oxygen on the cathode side to form water. The ammonia post-treatment SCR unit directly uses ammonia to reduce nitrogen oxides in the hydrogen-ammonia engine's exhaust.

[0053] During a cold start, the vehicle can be powered by a hydrogen-ammonia engine. This power is supplied to the ammonia cracker as needed for acceleration, deceleration, cornering, uphill and downhill driving, and parking. This generates and separates hydrogen, which is then used to support ammonia combustion in the hydrogen-ammonia engine. A portion of the remaining ammonia, after being supplied for combustion, enters the ammonia post-processing SCR unit to reduce nitrogen oxides, while the remaining portion (ammonia) enters the ammonia solid oxide fuel cell, where it is converted into electricity and stored in the power battery. Under normal speed conditions, the fuel cell system serves as the primary power source, improving energy efficiency. Under high speed and high load conditions, the hydrogen-ammonia engine serves as a supplementary power source, compensating for the fuel cell system's power deficit.

[0054] In this embodiment, the specific control idea is as follows: Figure 2As shown in the figure, after inputting the traction power command and the braking power command, the ECU calculates the indicated power P. The indicated power P is then evaluated. If it is less than 0, the power system brakes; if it is greater than 0, the power system engages traction and makes further evaluations. When the commanded power P exceeds the upper limit P2 of the power battery output power, hybrid traction is used. When the indicated power is within the power battery output power range P1-P2, electric motor traction is used. When the indicated power is less than the lower limit P1 of the power battery output, hydrogen-ammonia engine traction is used. When the electric motor system is used, the power battery state of charge (SOC) is further evaluated. When the power battery is within the reasonable SOC range of 20%-80%, the power battery and fuel cell jointly provide the required power. When the power battery charge exceeds 80%, the power battery discharges, and only the power battery is used to output the required power. When the power battery charge is less than 20%, the fuel cell outputs the required power while simultaneously charging the power battery.

[0055] When only the hydrogen-ammonia engine is used for traction, the hydrogen-ammonia engine power Pe is P, which alone provides power to the power system.

[0056] When only the fuel cell system is used for traction, the hydrogen-ammonia engine power Pe is 0 and the power battery SOC is lower than 20%. In addition to providing the power P required by the power system, the fuel cell also charges the power battery. The power battery charging power Pbc is the fuel cell rated power P3-P; when the power battery SOC is higher than 80%, the fuel cell stops working, the fuel cell power Pf=0, and the power battery provides the power P required by the power system; when the power battery SOC is in the reasonable range of 20%-80%, the sum of the fuel cell power Pf and the power battery power Pb is P.

[0057] When a hybrid power system is used, the hydrogen-ammonia engine power Pe is the indicated power P minus the power battery output upper limit power P2. When the power battery SOC is lower than 20%, the fuel cell not only provides the power battery upper limit power P2 but also charges the power battery. The power battery charging power Pbc is the fuel cell rated power P3 minus the power battery upper limit power P2. When the power battery SOC is higher than 80%, the fuel cell stops working, the fuel cell power Pf=0, and the power battery provides the power system upper limit power P2. When the power battery SOC is in the reasonable range of 20% to 80%, the sum of the fuel cell power Pf and the power battery power Pb is P2.

[0058] The multi-power system architecture provided by the present invention adopts hybrid power, and uses a hydrogen-ammonia engine and a fuel cell system as power sources. Hydrogen is used as it is produced, which avoids the storage and transportation problems of hydrogen and simplifies the structure. The system is based on hydrogen-ammonia fuel, and the two fuels complement each other to achieve zero carbon emissions. The use of ammonia for post-treatment gets rid of the dependence of traditional post-treatment devices on urea and achieves near-zero emissions of nitrogen oxides. This invention effectively reduces the use of fossil fuels. At the same time, ammonia as a hydrogen carrier has a mature supply chain, high energy density, and is easy to store and transport, and has broad application prospects.

[0059] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell, characterized in that: include: Liquid ammonia tank; a liquid ammonia gasification device, the liquid inlet of which is connected to the liquid outlet of the liquid ammonia tank; an ammonia tank, the air inlet of which is connected to the air outlet of the liquid ammonia gasification device; an ammonia online cracking hydrogen production device, the gas inlet of which is connected to the gas outlet of the liquid ammonia gasification device; A gas separation device is provided with an air inlet, an ammonia outlet, a hydrogen outlet and a nitrogen outlet; the air inlet of the gas separation device is connected to the air outlet of the ammonia online cracking hydrogen production device; Wherein, the ammonia outlet is connected to the air inlet of the ammonia tank; A hydrogen-ammonia engine having an ammonia inlet and a hydrogen inlet, wherein the ammonia inlet is connected to the gas outlet of the ammonia tank, and the hydrogen inlet is connected to the hydrogen outlet; Wherein, the injection mode of the hydrogen-ammonia engine is direct injection or compound injection; a transmission device, the input end of which is selectively connected to or disconnected from the power output end of the hydrogen-ammonia engine; an ammonia solid oxide fuel cell, the air inlet of which is in communication with the air outlet of the ammonia tank; a power battery, the input end of which is connected to the power output end of the ammonia solid oxide fuel cell; a motor, the power input end of which is connected to the output end of the power battery and / or the power output end of the ammonia solid oxide fuel cell; The power input end of the torque coupler is connected to the power output end of the motor and the power output end of the transmission device at the same time, and the power output end of the torque coupler transmits power to the vehicle drive system.

2. The multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell according to claim 1, characterized in that: Also includes: An ammonia SCR post-treatment device has an inlet that is simultaneously connected to the exhaust outlet of the hydrogen-ammonia engine and the gas outlet of the ammonia tank.

3. The multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell according to claim 2, characterized in that: Also includes: A waste heat recovery device, the inlet of which is connected to the outlet of the ammonia SCR post-treatment device, and the outlet of the waste heat recovery device is connected to the ammonia online cracking hydrogen production device, for providing heat to the ammonia online cracking hydrogen production device.

4. The multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell according to claim 3, characterized in that: The output end of the power battery is connected to the ammonia online cracking hydrogen production device.

5. The multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell according to claim 3 or 4, characterized in that: Also includes: A DC / DC inverter has one end connected to the power output end of the ammonia solid oxide fuel cell, and the other end connected to both the power battery and the motor.

6. The multi-power system based on a hydrogen-ammonia engine and an ammonia fuel cell according to claim 5, characterized in that: A clutch is provided between the input end of the transmission device and the power output end of the hydrogen-ammonia engine.

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