Coupled photo-thermal ammonia decomposition hydrogen production system

Abstract

The invention discloses a coupling photo-thermal ammonia decomposition hydrogen production system which comprises an ammonia decomposition reactor, a liquid ammonia storage tank, an ammonia gas heating device and a hydrogen storage tank, the ammonia gas heating device comprises a liquid ammonia water bath box, a first heat exchanger and a second heat exchanger, and a reaction gas pipeline of the first heat exchanger is connected with a reaction gas outlet of the ammonia decomposition reactor; and the second heat exchanger is connected with the fused salt high-temperature storage tank. According to the system, before ammonia gas enters the ammonia decomposition reactor, the ammonia gas is subjected to heat exchange twice through high-temperature gas after reaction in the first heat exchanger and high-temperature fused salt in the second heat exchanger, so that the temperature of the ammonia gas is close to the reaction temperature, the reaction rate of the ammonia decomposition reactor is increased, the system can enter a stable production state as soon as possible, and the production efficiency is improved. The light splitting filter distributes light waves with proper wave bands to the solar heat collector and the photovoltaic power generation equipment, electric energy is provided for the electrochemical energy storage device while molten salt is heated, and energy supply of the system is green, environment-friendly and energy-saving.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production equipment, and in particular to a coupled photothermal ammonia decomposition hydrogen production system. Background Art

[0002] Ammonia decomposition to produce hydrogen is a reversible reaction with strong endothermic volume expansion. High temperature and low pressure favor the forward reaction, resulting in pollution-free nitrogen and hydrogen as the reaction products. Furthermore, the higher the gas temperature before entering the reactor, the faster the reaction, the less heat required to replenish the system, and a more uniform temperature field within the reactor. Currently, industrially used ammonia decomposition reactors primarily rely on electrical heating to heat the reactor's exterior. However, due to the relatively low temperature in the reactor's center and the endothermic nature of the reaction, the internal temperature of the reactor remains relatively low, resulting in low conversion rates. Furthermore, the equipment consumes a lot of energy and is expensive to manufacture. Summary of the Invention

[0003] The purpose of the present invention is to provide a coupled photothermal ammonia decomposition hydrogen production system, in which the ammonia is subjected to two heat exchanges before entering the ammonia decomposition reactor, through the high-temperature gas after the reaction in the first heat exchanger and the high-temperature molten salt in the second heat exchanger, so that the temperature of the ammonia is close to the reaction temperature, the reaction rate of the ammonia decomposition reactor is accelerated, and the system can enter a stable production state as soon as possible, thereby improving production efficiency.

[0004] To achieve the above object, the technical solution adopted by the present invention is: A coupled photothermal ammonia decomposition hydrogen production system comprises an ammonia decomposition reactor, a liquid ammonia storage tank, an ammonia heating device, and a hydrogen storage tank. The ammonia heating device comprises a liquid ammonia water bath, a first heat exchanger, and a second heat exchanger. The ammonia pipeline inlet of the liquid ammonia water bath is connected to the liquid ammonia storage tank, the ammonia pipeline outlet of the liquid ammonia water bath is connected in series with the ammonia pipelines of the first heat exchanger and the second heat exchanger, the ammonia channel in the second heat exchanger is connected to the ammonia inlet of the ammonia decomposition reactor, the reaction gas outlet of the ammonia decomposition reactor is connected to the air inlet of the post-reaction gas channel of the first heat exchanger, the air outlet of the post-reaction gas channel of the first heat exchanger is connected to the air inlet of the post-reaction gas channel of a cooler, the air outlet of the post-reaction gas channel of the cooler is connected in series with a drying tank and an adsorption device, and the hydrogen outlet of the adsorption device is connected to the hydrogen storage tank; the cooling medium channel inlet of the cooler is connected to a cooling water source; The molten salt channel inlet of the second heat exchanger is connected to the outlet of the molten salt high-temperature storage tank, the molten salt channel outlet of the second heat exchanger is connected to the inlet of the molten salt low-temperature storage tank, and the outlet of the molten salt low-temperature storage tank is connected in series with the solar collector and the molten salt high-temperature storage tank in sequence; The ammonia decomposition reactor is connected to the electrochemical energy storage device, and the electrochemical energy storage device is connected to the power supply unit.

[0005] Preferably, the solar thermal collector is connected to a spectroscopic filter, and the spectroscopic filter is connected to a photovoltaic power generation device.

[0006] Preferably, the power supply unit includes a photovoltaic power generation device, the photovoltaic power generation device is connected to a photovoltaic inverter, the photovoltaic inverter is connected to an electrochemical energy storage device, and the input end of the electrochemical energy storage device is also connected to the energy control device.

[0007] Preferably, the power supply unit includes a wind turbine generator set, the wind turbine generator set is connected to a wind power converter, the wind power converter is connected to an electrochemical energy storage device, and the input end of the electrochemical energy storage device is also connected to the energy control device.

[0008] Preferably, the heat medium pipeline of the liquid ammonia water bath is connected to the lower end of the cooling medium pipeline of the cooler, and the upper end of the medium pipeline of the cold zone of the cooler is connected to the cooling water source.

[0009] Preferably, the ammonia decomposition reactor includes a cylinder and a cylinder cover connected to each other, a cylindrical inner liner is installed in the inner cavity of the cylinder, the bottom of the inner liner is connected to the inner liner support seat installed on the bottom wall of the cylinder, and several electric heating rods parallel to the inner liner are evenly distributed on the outside of the inner liner. A preheating coil is provided on the outside of the electric heating rod, the upper end of the preheating coil is connected to the ammonia inlet, the lower end of the preheating coil is connected to the inlet of a U-shaped coil pipe, the outlet of the coil pipe extends to the bottom of the inner liner, the top of the inner liner is connected to the reaction gas outlet, the lower part of the ammonia inlet, the lower part of the reaction gas outlet and the top of the electric heating rod all pass through the cylinder cover, and the electric heating rod is connected to the electrochemical energy storage device.

[0010] Preferably, the top of the inner liner is sequentially installed with a gas outlet grid plate and an inner liner upper cover from bottom to top, and the inner liner upper cover is connected to the bottom of the reaction gas outlet; the bottom of the inner liner is sequentially installed with a gas inlet grid plate and an inner liner lower cover from top to bottom, and the outlet end of the coil pipe passes through the inner liner lower cover and extends to the bottom of the gas inlet grid plate.

[0011] Preferably, an electromagnetic induction heater is provided at the center of the inner container, and the upper portion of the electromagnetic induction heater passes through the inner container upper cover and the cylinder upper cover and is connected to the electrochemical energy storage device.

[0012] The working process of the present invention is: The liquid ammonia in the liquid ammonia storage tank is vaporized in the liquid ammonia water bath and enters the ammonia pipelines of the first heat exchanger and the second heat exchanger. The low-temperature ammonia in the second heat exchanger undergoes heat exchange with the high-temperature molten salt, and the ammonia temperature rises. The ammonia enters the ammonia decomposition reactor. After the decomposition reaction, the ammonia is decomposed into hydrogen and nitrogen. The high-temperature reaction gas enters the first heat exchanger through the reaction gas outlet. The high-temperature reaction gas undergoes the first heat exchange with the low-temperature ammonia in the first heat exchanger and then enters the cooler. After the second heat exchange with the cooling water in the cooler, it enters the drying tank for dehumidification and residual ammonia removal. After the nitrogen is discharged through the adsorption device, the hydrogen is collected and stored in the hydrogen storage tank.

[0013] In the system described in the present invention, the power supply method includes: (1) the spectroscopic filter filters the sunlight and selects appropriate light waves to transmit them to the solar collector and the photovoltaic power generation equipment respectively; the photovoltaic power generation equipment stores the electric energy in the electrochemical energy storage device through the photovoltaic inverter to provide power for the ammonia decomposition reactor; the solar collector heats the low-temperature molten salt; (2) the electrochemical energy storage device is also connected to the wind turbine, and the wind turbine provides power for the electrochemical energy storage device.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The system of the present invention performs two heat exchanges on ammonia before it enters the ammonia decomposition reactor, using the high-temperature gas after the reaction in the first heat exchanger and the high-temperature molten salt in the second heat exchanger. This allows the temperature of the ammonia to approach the reaction temperature, accelerates the reaction rate of the ammonia decomposition reactor, enables the system to enter a stable production state as quickly as possible, and improves production efficiency.

[0015] The present invention distributes sunlight to light waves of appropriate wavelengths through a spectroscopic filter to a solar collector and a photovoltaic power generation device, thereby improving the utilization of solar energy. At the same time, the solar collector heats the molten salt and supplies it to a second heat exchanger, and the photovoltaic power generation device provides electrical energy to an electrochemical energy storage device, thereby ensuring the power supply requirements of the ammonia decomposition reactor. The energy supply is green, environmentally friendly, and energy-saving.

[0016] The heat medium channel in the liquid ammonia water bath is connected to the lower end of the cooling medium pipe of the cooler. The ammonia gas with a lower temperature after vaporization and the cooling water with a slightly higher temperature in the cooling medium pipe of the cooler can initially exchange heat, thereby improving the quality and vaporization speed of the ammonia gas and efficiently utilizing the heat source.

[0017] In order to ensure the temperature of the ammonia decomposition reaction in the ammonia decomposition reactor, a preheating coil is set on the outside of the inner tank, and an electric heating rod is installed between the preheating coil and the inner tank. The electric heating rod can preheat the ammonia decomposition reactor and can quickly start the ammonia decomposition reactor. At the same time, the ammonia gas after secondary heat exchange runs in the coil to further ensure the heat required for the reaction of the ammonia decomposition reactor, thereby improving the performance of the product.

[0018] An electromagnetic induction heater connected to an electrochemical energy storage device is set at the center of the ammonia decomposition reactor. When the reaction temperature is not high enough, the electrochemical energy storage device can be used for heating, ensuring the smooth operation of the system.

[0019] The inner tank of the ammonia decomposition reactor is filled with catalyst, and grid plates are used as supports at both ends of the inner tank to facilitate gas inflow and outflow.

[0020] The reactor liner is placed separately in the cylinder to facilitate later maintenance and replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of this system; Figure 2 is a schematic structural diagram of an ammonia decomposition reactor; Figure 3 This is a schematic diagram of the structure of the inner tank, electric heating rod, and preheating coil inside the ammonia decomposition reactor; Figure 4 It is a schematic diagram of the structure of the inner tank of the ammonia decomposition reactor; Figure 1: Spectroscopic filter, 2. Photovoltaic power generation equipment, 3. Solar collector, 4. Molten salt high-temperature storage tank, 5. Molten salt low-temperature storage tank, 6. Liquid ammonia storage tank, 7. Molten salt pump, 8. Liquid ammonia bath, 9. First heat exchanger, 10. Second heat exchanger, 11. Ammonia decomposition reactor, 11.1. Cylinder cover, 11.2. Cylinder, 11.3. Ammonia inlet, 11.4. Reaction gas outlet, 11.5. Electric heating rod, 11.6. Preheating coil, 11.7. Coil Take over, 11.8, liner support base, 11.9, electromagnetic induction heater, 11.10, liner upper cover, 11.11, gas outlet grid plate, 11.12, liner, 11.13, gas inlet grid plate, 11.14, liner lower cover, 12, electrochemical energy storage device, 13, energy control valve, 14, cooler, 15, drying tank, 16, adsorption device, 17, wind power converter, 18, photovoltaic inverter, 19, wind turbine, 20, hydrogen storage tank. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings.

[0023] like Figures 1 to 4The coupled photothermal ammonia decomposition hydrogen production system shown includes an ammonia decomposition reactor 11, a liquid ammonia storage tank 6, an ammonia heating device, and a hydrogen storage tank 20. The ammonia heating device includes a liquid ammonia water bath 8, a first heat exchanger 9, and a second heat exchanger 10. The ammonia pipeline inlet of the liquid ammonia water bath 8 is connected to the liquid ammonia storage tank 6, and the ammonia pipeline outlet of the liquid ammonia water bath 8 is connected in series with the ammonia pipelines of the first heat exchanger 9 and the second heat exchanger 10 in sequence. The ammonia channel in the second heat exchanger 10 is connected to the ammonia inlet 1 of the ammonia decomposition reactor 11. 1.3, the reaction gas outlet 11.4 of the ammonia decomposition reactor 11 is connected to the air inlet of the post-reaction gas channel of the first heat exchanger 9, the air outlet of the post-reaction gas channel of the first heat exchanger 9 is connected to the air inlet of the post-reaction gas channel of the cooler 14, the air outlet of the post-reaction gas channel of the cooler 14 is connected in series with the drying tank 15 and the adsorption device 16, the hydrogen outlet of the adsorption device 16 is connected to the hydrogen storage tank 20; the cooling medium channel inlet of the cooler 14 is connected to the cooling water source; The molten salt channel inlet of the second heat exchanger 10 is connected to the outlet of the molten salt high-temperature storage tank 4, and the molten salt channel outlet of the second heat exchanger 10 is connected to the inlet of the molten salt low-temperature storage tank 5. The outlet of the molten salt low-temperature storage tank 5 is connected in series with the solar collector 3 and the molten salt high-temperature storage tank 4 in sequence; The ammonia decomposition reactor 11 is connected to the electrochemical energy storage device 12 , and the electrochemical energy storage device 12 is connected to the power supply unit.

[0024] The solar thermal collector 3 is connected to the spectroscopic filter 1 , and the spectroscopic filter 1 is connected to the photovoltaic power generation device 2 .

[0025] The power supply unit includes a photovoltaic power generation device 2 , which is connected to a photovoltaic inverter 18 , which is connected to an electrochemical energy storage device 12 , and an input end of the electrochemical energy storage device 12 is also connected to an energy control device 13 .

[0026] The power supply unit includes a wind turbine 19 , which is connected to a wind power converter 17 , which is connected to an electrochemical energy storage device 12 , and an input end of the electrochemical energy storage device 12 is also connected to an energy control device 13 .

[0027] The heat medium pipeline of the liquid ammonia water bath tank 8 is connected to the lower end of the cooling medium pipeline of the cooler 14, and the upper end of the cold zone medium pipeline is connected to the cooling water source.

[0028] The ammonia decomposition reactor 11 comprises a cylinder 11.2 and a cylinder cover 11.1 which are connected to each other. A cylindrical inner liner 11.12 is installed in the inner cavity of the cylinder 11.2. The bottom of the inner liner 11.12 is connected to an inner liner support 11.8 installed on the bottom wall of the cylinder 11.2. Several electric heating rods 11.5 are evenly distributed on the outer side of the inner liner 11.12 and are parallel to the inner liner 11.12. A preheating coil 11.6 is installed on the outer side of the electric heating rod 11.5. The upper end of the preheating coil 11.6 is connected to the inner liner support 11.8. The ammonia inlet 11.3 is connected, the lower end of the preheating coil 11.6 is connected to the inlet of the U-shaped coil pipe 11.7, the outlet of the coil pipe 11.7 extends to the bottom of the inner liner 11.12, and the top of the inner liner 11.12 is connected to the reaction gas outlet 11.4. The lower part of the ammonia inlet 11.3, the lower part of the reaction gas outlet 11.4 and the top of the electric heating rod 11.5 all pass through the cylinder cover 11.1, and the electric heating rod 11.5 is connected to the electrochemical energy storage device 12.

[0029] The top of the inner liner 11.12 is installed with a gas outlet grid plate 11.11 and an inner liner upper cover 11.10 from bottom to top, and the inner liner upper cover 11.10 is connected to the bottom of the reaction gas outlet 11.4; the bottom of the inner liner 11.12 is installed with a gas inlet grid plate 11.13 and an inner liner lower cover 11.14 from top to bottom, and the outlet end of the coil pipe 11.7 passes through the inner liner lower cover 11.14 and extends to the bottom of the gas inlet grid plate 11.13.

[0030] An electromagnetic induction heater 11.9 is provided at the center of the inner liner 11.12. The upper portion of the electromagnetic induction heater 11.9 passes through the inner liner upper cover 11.10 and the cylinder upper cover 11.1 and is connected to the electrochemical energy storage device 12.

[0031] The working process of the present invention is: Liquid ammonia is vaporized to undergo a decomposition reaction: The liquid ammonia in the liquid ammonia storage tank 6 is vaporized in the liquid ammonia water bath 8 and then enters the ammonia pipelines of the first heat exchanger 9 and the second heat exchanger 10. The low-temperature ammonia in the second heat exchanger 10 undergoes heat exchange with the high-temperature molten salt, raising the ammonia temperature. The ammonia enters the ammonia decomposition reactor 11. After the decomposition reaction, the ammonia decomposes into hydrogen and nitrogen. The high-temperature reaction gas enters the first heat exchanger 9 through the reaction gas outlet 11.4. The high-temperature reaction gas undergoes a first heat exchange with the low-temperature ammonia in the first heat exchanger 9 and then enters the cooler 14. After a second heat exchange with the cooling water in the cooler 14, the high-temperature reaction gas enters the drying tank 15 for dehumidification and residual ammonia removal. After the nitrogen is discharged through the adsorption device 16, the hydrogen is collected and stored in the hydrogen storage tank 20. Power supply: The spectroscopic filter 1 filters the sunlight and selects appropriate light waves to transmit to the solar collector 3 and the photovoltaic power generation device 2 respectively; the solar collector 3 heats the low-temperature molten salt; the photovoltaic power generation device 2 stores the electrical energy in the electrochemical energy storage device 12 through the photovoltaic inverter 18, providing power for the ammonia decomposition reactor 11; the electrochemical energy storage device 12 is also connected to the wind turbine 19, which provides power for the electrochemical energy storage device 12.

[0032] The system of the present invention performs two heat exchanges on ammonia before it enters the ammonia decomposition reactor, using the high-temperature gas after the reaction in the first heat exchanger and the high-temperature molten salt in the second heat exchanger. This allows the temperature of the ammonia to approach the reaction temperature, accelerates the reaction rate of the ammonia decomposition reactor, enables the system to enter a stable production state as quickly as possible, and improves production efficiency.

[0033] The above are only preferred embodiments of the present invention. It should be noted that those skilled in the art can make other equivalent variations and improvements based on the technical enlightenment provided by the present invention, which should also be considered as the scope of protection of the present invention.

Claims

1. A coupled photothermal ammonia decomposition hydrogen production system, characterized by: The invention comprises an ammonia decomposition reactor (11), a liquid ammonia storage tank (6), an ammonia heating device, and a hydrogen storage tank (20). The ammonia heating device comprises a liquid ammonia water bath (8), a first heat exchanger (9), and a second heat exchanger (10). The ammonia pipeline air inlet of the liquid ammonia water bath (8) is connected to the liquid ammonia storage tank (6). The ammonia pipeline air outlet of the liquid ammonia water bath (8) is connected in series with the ammonia pipelines of the first heat exchanger (9) and the second heat exchanger (10). The ammonia channel in the second heat exchanger (10) is connected to the ammonia inlet (11.3) of the ammonia decomposition reactor (11). The reaction gas outlet (11.4) of the ammonia decomposition reactor (11) is connected to the air inlet of the reaction gas channel of the first heat exchanger (9), the air outlet of the reaction gas channel of the first heat exchanger (9) is connected to the air inlet of the reaction gas channel of the cooler (14), the air outlet of the reaction gas channel of the cooler (14) is connected in series with the drying tank (15) and the adsorption device (16), and the hydrogen outlet of the adsorption device (16) is connected to the hydrogen storage tank (20); the cooling medium channel inlet of the cooler (14) is connected to a cooling water source; The inlet of the molten salt channel of the second heat exchanger (10) is connected to the outlet of the molten salt high-temperature storage tank (4), the outlet of the molten salt channel of the second heat exchanger (10) is connected to the inlet of the molten salt low-temperature storage tank (5), and the outlet of the molten salt low-temperature storage tank (5) is connected in series with the solar collector (3) and the molten salt high-temperature storage tank (4) in sequence; The ammonia decomposition reactor (11) is connected to the electrochemical energy storage device (12), and the electrochemical energy storage device (12) is connected to the power supply unit.

2. The coupled photothermal ammonia decomposition hydrogen production system according to claim 1 is characterized by: The solar thermal collector (3) is connected to the spectroscopic filter (1), and the spectroscopic filter (1) is connected to the photovoltaic power generation equipment (2).

3. The coupled photothermal ammonia decomposition hydrogen production system according to claim 1 or 2, characterized in that: The power supply unit comprises a photovoltaic power generation device (2), the photovoltaic power generation device (2) is connected to a photovoltaic inverter (18), the photovoltaic inverter (18) is connected to an electrochemical energy storage device (12), and the input end of the electrochemical energy storage device (12) is also connected to an energy control device (13).

4. The coupled photothermal ammonia decomposition method for hydrogen production according to claim 1, characterized in that: The power supply unit comprises a wind turbine set (19), the wind turbine set (19) is connected to a wind power converter (17), the wind power converter (17) is connected to an electrochemical energy storage device (12), and the input end of the electrochemical energy storage device (12) is also connected to an energy control device (13).

5. The coupled photothermal ammonia decomposition hydrogen production system according to claim 1 is characterized by: The hot medium pipeline of the liquid ammonia water bath (8) is connected to the lower end of the cooling medium pipeline of the cooler (14), and the upper end of the cold zone medium pipeline is connected to a cooling water source.

6. The coupled photothermal ammonia decomposition hydrogen production system according to claim 1, characterized in that: The ammonia decomposition reactor (11) comprises a cylinder (11.2) and a cylinder upper cover (11.1) which are connected to each other. A cylindrical inner liner (11.12) is installed in the inner cavity of the cylinder (11.2). The bottom of the inner liner (11.12) is connected to an inner liner support seat (11.8) installed on the bottom wall of the cylinder (11.2). A plurality of electric heating rods (11.5) parallel to the inner liner (11.12) are evenly distributed on the outer side of the inner liner (11.12). A preheating coil (11.6) is arranged on the outer side of the electric heating rod (11.5). The upper side of the preheating coil (11.6) The end is connected to the ammonia inlet (11.3), the lower end of the preheating coil (11.6) is connected to the inlet of the U-shaped coil pipe connection (11.7), the outlet of the coil pipe connection (11.7) extends to the bottom of the inner tank (11.12), the top of the inner tank (11.12) is connected to the reaction gas outlet (11.4), the lower part of the ammonia inlet (11.3), the lower part of the reaction gas outlet (11.4) and the top of the electric heating rod (11.5) all penetrate the cylinder upper cover (11.1), and the electric heating rod (11.5) is connected to the electrochemical energy storage device (12).

7. The coupled photothermal ammonia decomposition hydrogen production system according to claim 6, characterized in that: The top of the inner liner (11.12) is provided with a gas outlet grid plate (11.11) and an inner liner upper cover (11.10) in sequence from bottom to top, and the inner liner upper cover (11.10) is connected to the bottom of the reaction gas outlet (11.4); the bottom of the inner liner (11.12) is provided with a gas inlet grid plate (11.13) and an inner liner lower cover (11.14) in sequence from top to bottom, and the outlet end of the coil pipe (11.7) passes through the inner liner lower cover (11.14) and extends to the bottom of the gas inlet grid plate (11.13).

8. The coupled photothermal ammonia decomposition hydrogen production system according to claim 6 or 7, characterized in that: An electromagnetic induction heater (11.9) is arranged at the center of the inner tank (11.12), and the upper part of the electromagnetic induction heater (11.9) penetrates the inner tank upper cover (11.10) and the cylinder upper cover (11.1) to be connected to the electrochemical energy storage device (12).

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