Novel efficient ammonia hydrogen fuel cell system

Abstract

The utility model relates to a novel efficient ammonia-hydrogen fuel cell system which comprises a liquid ammonia tank, a vaporizer, a preheater, a membrane reactor, a turbine, a compressor and a fuel cell. The liquid ammonia tank, the vaporizer, the preheater and the membrane reactor are sequentially connected in series. The interior of the membrane reactor is divided into an ammonia decomposition area, a non-permeation area and a permeation area, the ammonia decomposition area is communicated with the non-permeation area, a hydrogen separation membrane is arranged between the non-permeation area and the permeation area, and the ammonia decomposition area is communicated with the preheater. The non-permeable area of the membrane reactor is connected with the turbine, the permeable area is connected with the compressor, the turbine is coaxially communicated with the compressor, and the compressor is connected with the fuel cell. Through the design of the membrane reactor, hydrogen moves towards the permeation zone, the hydrogen concentration of the reactor is reduced, the catalyst efficiency is improved, the catalyst dosage is reduced, and the cost is reduced. Meanwhile, the hydrogen pressure on the permeation side is increased by utilizing the internal energy of decomposed gas on the non-permeation side, the inlet pressure requirement of the fuel cell is met, the compression power consumption is saved, and the energy efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen energy power generation equipment technology, specifically to an ammonia-hydrogen fuel cell micro-engine system that uses ammonia as fuel and is coupled with a burner. Background Technology

[0002] Hydrogen is a clean secondary energy source with excellent characteristics such as high calorific value, good combustion performance, environmental friendliness, and recyclability. Its reaction with oxygen produces only water as a byproduct. However, hydrogen is flammable and explosive, and its low bulk density makes it difficult to store and transport, thus keeping the end-use cost of hydrogen energy consistently high. Ammonia, on the other hand, is stable, and its production process is mature, allowing for easy acquisition, transportation, and storage. Using ammonia as a carrier to obtain hydrogen through ammonia decomposition and coupling it with a hydrogen fuel cell has become an effective way to utilize hydrogen energy. However, existing ammonia decomposition fuel cell systems suffer from drawbacks such as large catalyst loading, large volume, and high reaction temperature in the ammonia decomposition reactor, resulting in low energy utilization efficiency. Utility Model Content

[0003] To address the shortcomings of existing fuel cell systems coupled with ammonia decomposition, such as high catalyst requirements, large reactor volume, high energy consumption, and low energy utilization, this paper proposes an ammonia-hydrogen fuel cell system with a micro-engine that features high ammonia decomposition efficiency, high system energy utilization, and low energy consumption.

[0004] The technical solution adopted by this utility model to solve its technical problem is: a novel high-efficiency ammonia-hydrogen fuel cell system, including a liquid ammonia tank, a vaporizer, a preheater, a membrane reactor, a turbine, a compressor, and a fuel cell; the liquid ammonia tank, vaporizer, preheater, and membrane reactor are connected in series in sequence; the membrane reactor is divided into an ammonia decomposition zone, a non-permeable zone, and a permeable zone; the ammonia decomposition zone is connected to the non-permeable zone, and a hydrogen separation membrane is set between the non-permeable zone and the permeable zone; the ammonia decomposition zone is connected to the preheater; the non-permeable zone of the membrane reactor is connected to the turbine, and the permeable zone of the membrane reactor is connected to the compressor, with the turbine and compressor coaxially connected; the compressor is then connected to the fuel cell.

[0005] Furthermore, the ammonia decomposition zone is filled with an ammonia decomposition catalyst, which is either a ruthenium-based or nickel-based catalyst. The ammonia decomposition zone is a closed structure, and the outside of the ammonia decomposition zone is covered with insulation cotton.

[0006] Furthermore, it also includes an air compressor, which is connected to the fuel cell.

[0007] Furthermore, a heating device is connected to the outside of the ammonia decomposition zone. The heating device can be an electric heating device or a flue gas duct. The heating device is used to heat the ammonia gas in the ammonia decomposition zone.

[0008] Furthermore, it also includes a burner, a heating device that is a flue gas duct, and the anode outlet and cathode outlet of the fuel cell are simultaneously connected to the burner; the combustion outlet of the burner is connected to the heating device, and the heating device is then connected in sequence to the preheater and the vaporizer.

[0009] Furthermore, the turbine is connected to the burner.

[0010] Furthermore, a burner is installed between the non-permeable zone of the membrane reactor and the turbine, and the burner is also connected to the anode outlet and cathode outlet of the fuel cell.

[0011] Furthermore, a second turbine is connected to the outlet of the turbine, and the second turbine is then connected to a heating device on the membrane reactor; the heating device is connected in sequence to the preheater and the vaporizer.

[0012] The novel high-efficiency ammonia-hydrogen fuel cell system described in this invention features a process where, during ammonia decomposition, the decomposed hydrogen continuously moves towards the permeate zone, resulting in a lower hydrogen concentration in the reactor. This leads to improved catalyst efficiency at the reactor's downstream end and a more complete reaction. Consequently, the membrane reactor can reduce the amount of catalyst used, thereby lowering catalyst costs. Furthermore, utilizing the internal energy of the decomposed gas on the non-permeate side of the membrane reactor to increase the hydrogen pressure on the permeate side can meet the fuel cell's inlet pressure requirements, saving compression power consumption and improving energy efficiency. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model, the accompanying drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of a novel high-efficiency ammonia-hydrogen fuel cell system according to the present invention;

[0015] Figure 2 This is a schematic diagram of another novel high-efficiency ammonia-hydrogen fuel cell system described in this utility model. Detailed Implementation

[0016] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0017] like Figure 1As shown, the present invention discloses a novel high-efficiency ammonia-hydrogen fuel cell system, comprising a liquid ammonia tank 1, a vaporizer 2, a preheater 3, a membrane reactor 4, a turbine 5, a compressor 6, and a fuel cell 7.

[0018] The liquid ammonia tank 1, the vaporizer 2, the preheater 3, and the membrane reactor 4 are connected in series. The membrane reactor 4 is internally divided into an ammonia decomposition zone, a non-permeable zone, and a permeable zone. The ammonia decomposition zone is connected to the non-permeable zone, and a hydrogen separation membrane is provided between the non-permeable zone and the permeable zone. The ammonia decomposition zone is connected to the preheater 3.

[0019] The non-permeable zone of the membrane reactor 4 is connected to the turbine 5, and the permeable zone of the membrane reactor is connected to the compressor 6. The turbine 5 and the compressor 6 are coaxially connected. The compressor 6 is then connected to the fuel cell 7.

[0020] like Figure 1 As shown, the liquid ammonia tank 1 is connected to the vaporizer 2, and the vaporizer 2 is connected to the preheater 3. The vaporizer 2 can heat the liquid ammonia introduced into the liquid ammonia tank 1, raise the temperature of the liquid ammonia and evaporate it into ammonia gas. The evaporated ammonia gas is then introduced into the preheater 3 for further preheating, so as to increase the amount of ammonia gas entering the membrane reactor 4. This allows the ammonia gas to undergo decomposition reaction more quickly, thereby improving the ammonia decomposition efficiency in the membrane reactor 4.

[0021] The membrane reactor 4 includes an ammonia decomposition zone, a non-permeable zone, and a permeable zone. The ammonia decomposition zone is connected to the non-permeable zone, and the non-permeable zone is connected to the permeable zone. The ammonia decomposition zone is connected to the preheater 3. A heating device is connected to the outside of the ammonia decomposition zone. Specifically, the heating device is an electric heating device or a flue gas duct. When the heating device is an electric heating device, it is fixed inside the ammonia decomposition zone and in direct contact with the gas inside the ammonia decomposition zone. When the heating device is a flue gas duct, it is attached to the outer surface of the ammonia decomposition zone. The heating device can heat the ammonia gas inside the ammonia decomposition zone to provide heat for the ammonia decomposition reaction. Preferably, the ammonia decomposition zone is filled with an ammonia decomposition catalyst, which is a ruthenium-based catalyst or a nickel-based catalyst. The ammonia decomposition catalyst can reduce the chemical energy required for the ammonia decomposition reaction, allowing the ammonia gas to decompose more quickly and generate hydrogen and nitrogen. The ammonia decomposition zone is a closed structure, and the outside of the ammonia decomposition zone is covered with insulation cotton to prevent heat loss during operation.

[0022] The ammonia decomposition zone and the non-permeable zone are separated by a partition with multiple through holes. These through holes allow hydrogen and nitrogen produced in the ammonia decomposition zone to enter the non-permeable zone. The non-permeable zone then communicates with the permeable zone, which is separated by a hydrogen separation membrane. One side of the hydrogen separation membrane is the non-permeable zone, and the other side is the permeable zone. The hydrogen separation membrane is a hydrogen-selective permeable membrane, such as a palladium membrane. Due to the selective permeability of the hydrogen separation membrane, hydrogen is enriched in the permeable zone, while nitrogen and unreacted ammonia remain in the non-permeable zone.

[0023] The outlet of the permeation zone is connected to the compressor 6, and the outlet of the non-permeation zone is connected to the turbine 5. The hydrogen separated in the permeation zone enters the compressor 6 for compression, while the high-temperature, high-pressure gas separated in the non-permeation zone, along with high-temperature, high-pressure nitrogen and a small amount of unreacted ammonia, enters the turbine 5, using its own heat and pressure to drive the turbine 5 to do work. The turbine 5 is then coaxially connected to the compressor 6. When the turbine 5 is driven by the high-temperature, high-pressure nitrogen and a small amount of unreacted ammonia, it can synchronously drive the coaxially connected compressor 6 to rotate, thereby completing the compression of the hydrogen entering the compressor 6. This achieves simultaneous and effective utilization of the hydrogen and separated nitrogen during the separation process, improving system operating efficiency and reducing the system's demand for external power, thus reducing system energy consumption. The compressed hydrogen directly enters the anode inlet of the fuel cell 7.

[0024] Preferably, in order to increase the flow rate of gas entering the fuel cell 7 and improve the power generation effect of the fuel cell 7, the cathode inlet of the fuel cell 7 is connected to the air compressor 9, which can compress air and then enter the fuel cell 7. The fuel cell 7 converts the chemical energy of hydrogen compressed from the compressor 6 and air introduced from the air compressor 9 into electrical energy, thus completing the power generation of the system.

[0025] The novel high-efficiency ammonia-hydrogen fuel cell system also includes a burner 8. The anode outlet and cathode outlet of the fuel cell 7 are simultaneously connected to the burner 8. The exhaust gas discharged after the fuel cell 7 generates electricity, including water vapor, a small amount of hydrogen, and oxygen from the air, can enter the burner 8 for combustion. In order to more effectively improve the combustion effect of the burner 8 and more effectively utilize the gas and its energy generated during system operation, preferably, the turbine 5 is also connected to the burner 8. The nitrogen gas and a small amount of unreacted ammonia gas after the turbine 5 has done work enter the burner 8 to improve the combustion effect of the burner 8. The combustion gas produced by the burner 8 after combustion has a high temperature.

[0026] To effectively utilize the gas produced by the burner 8, preferably, the combustion outlet of the burner 8 is connected to a heating device on the ammonia decomposition zone. The heating device is a flue gas duct, allowing the gas produced by the burner 8 to enter the heating device and heat the ammonia gas inside the ammonia decomposition zone. Compared to electric heating, this reduces the heat source required for ammonia decomposition, thus reducing system energy consumption and effectively improving system energy utilization. The flue gas duct on the ammonia decomposition zone is connected to the preheater 3, which is in turn connected to the vaporizer 2. After the gas from the burner 8 has heated the ammonia gas in the ammonia decomposition zone, the combustion gas... The gas then passes sequentially through the preheater 3 and the vaporizer 2, respectively, to provide heat for heating the preheater 3 and the vaporizer 2; this achieves the reuse of heat generated by the combustion of the burner 8 and improves the heating effect of the preheater 3 and the vaporizer 2, reducing the energy consumption of the system and helping to increase the temperature of the ammonia entering the membrane reactor 4; the heated gas is directly discharged from the vaporizer 2. Since the burner 8 uses the gas discharged from the fuel cell 7 and the gas after ammonia decomposition discharged from the membrane reactor 4 as fuel, the main products of the combustion gas are water vapor and nitrogen; this greatly reduces the risk of greenhouse gases or harmful gases being directly released into the air.

[0027] like Figure 2 As shown, a burner 8 is provided between the non-permeable zone of the membrane reactor 4 and the turbine 5. The burner 8 is connected to both the anode outlet and the cathode outlet of the fuel cell 7. The burner 8 can mix and burn the gas discharged from the fuel cell 7. The gas discharged from the non-permeable zone of the membrane reactor 4, namely high-temperature and high-pressure nitrogen and unreacted ammonia, is introduced into the burner 8 to increase the temperature required for combustion. The gas after combustion then enters the turbine 5 to drive the turbine 5 to do work and drive the coaxially linked compressor 6 to compress the hydrogen gas separated from the permeable zone of the membrane reactor 4. The compressed hydrogen gas then enters the fuel cell 7 to generate electricity.

[0028] exist Figure 2In this system, the outlet of turbine 5 is also connected to a second turbine 51. The high-temperature and high-pressure gas that has done work in turbine 5 drives the second turbine 51 to generate electricity again, increasing the electrical energy generated in the system. The high-temperature and high-pressure gas that has done work in the second turbine 51 to generate electricity is discharged from the second turbine 51 and then enters the heating device outside the ammonia decomposition zone of the membrane reactor 4. The heating device is a flue gas pipe. After the high-temperature and high-pressure gas discharged from the second turbine 51 enters the flue gas pipe, it heats the ammonia in the ammonia decomposition zone, promoting the decomposition of ammonia. After being heated, it is discharged from the flue gas pipe and flows sequentially through the preheater 3 and the vaporizer 2, continuing to provide heat to the preheater 3 and the vaporizer 2 and heating the ammonia therein. The heated gas is then discharged through the vaporizer 2.

[0029] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A novel high-efficiency ammonia-hydrogen fuel cell system, comprising a liquid ammonia tank, a vaporizer, a preheater, a membrane reactor, a turbine, a compressor, and a fuel cell; characterized in that: The liquid ammonia tank, the vaporizer, the preheater, and the membrane reactor are connected in series. The membrane reactor is internally divided into an ammonia decomposition zone, a non-permeable zone, and a permeable zone. The ammonia decomposition zone is connected to the non-permeable zone, and a hydrogen separation membrane is provided between the non-permeable zone and the permeable zone. The ammonia decomposition zone is connected to the preheater. The non-permeable zone of the membrane reactor is connected to the turbine, the permeable zone of the membrane reactor is connected to the compressor, and the turbine and the compressor are coaxially connected; the compressor is then connected to the fuel cell.

2. The novel high-efficiency ammonia-hydrogen fuel cell system according to claim 1, characterized in that: The ammonia decomposition zone is filled with an ammonia decomposition catalyst, which is a ruthenium-based catalyst or a nickel-based catalyst. The ammonia decomposition zone is a closed structure, and the outside of the ammonia decomposition zone is covered with thermal insulation cotton.

3. The novel high-efficiency ammonia-hydrogen fuel cell system according to claim 1, characterized in that: It also includes an air compressor, which is connected to the fuel cell.

4. The novel high-efficiency ammonia-hydrogen fuel cell system according to claim 1, characterized in that: The ammonia decomposition zone is externally connected to a heating device, which can be an electric heating device or a flue gas duct; the heating device is used to heat the ammonia gas in the ammonia decomposition zone.

5. A novel high-efficiency ammonia-hydrogen fuel cell system according to claim 4, characterized in that: It also includes a burner, the heating device being a flue gas duct, and the anode outlet and cathode outlet of the fuel cell being connected to the burner simultaneously; the combustion outlet of the burner is connected to the heating device, and the heating device is then connected in sequence to the preheater and the vaporizer.

6. A novel high-efficiency ammonia-hydrogen fuel cell system according to claim 5, characterized in that: The turbine is connected to the burner.

7. A novel high-efficiency ammonia-hydrogen fuel cell system according to claim 4, characterized in that: A burner is disposed between the non-permeable zone of the membrane reactor and the turbine, and the burner is also connected to the anode outlet and cathode outlet of the fuel cell.

8. A novel high-efficiency ammonia-hydrogen fuel cell system according to claim 7, characterized in that: A second turbine is connected to the outlet of the turbine, and the second turbine is then connected to a heating device on the membrane reactor; the heating device is sequentially connected to the preheater and the vaporizer.

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