Synthetic ammonia coupling system

Abstract

The utility model discloses a synthetic ammonia coupling system. The system comprises a liquid air energy storage subsystem, a synthesis ammonia subsystem and an SOEC hydrogen production subsystem, the liquid air energy storage subsystem comprises an air separation unit and a power generation unit, a nitrogen outlet of the air separation unit is communicated with a nitrogen inlet of the power generation unit, a nitrogen outlet of the air separation unit is communicated with a nitrogen inlet of the synthesis ammonia subsystem, and a nitrogen outlet of the power generation unit is communicated with a nitrogen inlet of the synthesis ammonia subsystem; the electric energy output end of the power generation unit is electrically connected with the electric energy input ends of the ammonia synthesis subsystem and the SOEC hydrogen production subsystem respectively; a compressed air outlet of the air separation unit is communicated with a compressed air inlet of the SOEC hydrogen production subsystem; and the ammonia synthesis heat output end of the ammonia synthesis subsystem is communicated with the ammonia synthesis heat input end of the power generation unit. According to the embodiment of the invention, coupling of a liquid air energy storage technology, a solid oxide electrolytic tank technology and an ammonia gas synthesis technology can be enhanced, and the energy efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of synthetic ammonia, in particular to a synthetic ammonia coupling system. BACKGROUND

[0002] Under the global trend of low-carbon and green energy transformation, the traditional energy system is facing remolding, and the fusion innovation of new energy technology has become the key to breaking through the situation.

[0003] At present, a coupling system of liquid air energy storage technology (LAES), solid oxide electrolysis cell technology (SOEC) and ammonia synthesis technology has emerged. However, the energy efficiency in the prior art is low. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a synthetic ammonia coupling system to strengthen the coupling of liquid air energy storage technology, solid oxide electrolysis cell technology and ammonia synthesis technology, and improve energy efficiency.

[0005] According to an aspect of the present application, a synthetic ammonia coupling system is provided, comprising: a liquid air energy storage subsystem, a synthetic ammonia subsystem and a SOEC hydrogen production subsystem;

[0006] The liquid air energy storage subsystem comprises an air separation unit and a power generation unit, a nitrogen gas outlet of the air separation unit is in communication with a nitrogen gas inlet of the power generation unit, and a nitrogen gas outlet of the air separation unit is in communication with a nitrogen gas inlet of the synthetic ammonia subsystem, and a nitrogen gas outlet of the power generation unit is in communication with a nitrogen gas inlet of the synthetic ammonia subsystem; an electric energy output end of the power generation unit is electrically connected with an electric energy input end of the synthetic ammonia subsystem and the SOEC hydrogen production subsystem, respectively;

[0007] A compressed air outlet of the air separation unit is in communication with a compressed air inlet of the SOEC hydrogen production subsystem; a hydrogen gas outlet of the SOEC hydrogen production subsystem is in communication with a hydrogen gas inlet of the synthetic ammonia subsystem;

[0008] An ammonia gas synthesis heat output end of the synthetic ammonia subsystem is in communication with an ammonia gas synthesis heat input end of the power generation unit.

[0009] Optionally, the air separation unit comprises an air compressor and an air separation device;

[0010] The compressed air outlet of the air compressor is in communication with the compressed air inlet of the air separation device, and the nitrogen gas outlet of the air separation device is in communication with the nitrogen gas inlet of the power generation unit and the nitrogen gas inlet of the synthetic ammonia subsystem, respectively;

[0011] The compressed air outlet of the air compressor is in communication with the compressed air inlet of the SOEC hydrogen production subsystem.

[0012] Optionally, the power generation unit comprises a nitrogen compressor, an oil tank, a liquid nitrogen storage tank, an expander, a turbine and a generator;

[0013] The nitrogen inlet of the nitrogen compressor is in communication with the nitrogen outlet of the air separation device, the heat output end of the nitrogen compressor is in communication with the heat input end of the oil tank, and the liquid nitrogen outlet of the nitrogen compressor is in communication with the liquid nitrogen inlet of the liquid nitrogen storage tank;

[0014] The liquid nitrogen outlet of the liquid nitrogen storage tank is in communication with one end of the expander, the other end of the expander is in communication with one end of the turbine, and the other end of the turbine is in communication with the generator;

[0015] Optionally, the heat output end of the oil tank is gated with the heated end of the expander.

[0016] Optionally, the synthetic ammonia subsystem comprises a gas mixing tank, a mixed gas compressor, a first heat exchanger, a first heating device and a reaction tower which are sequentially in communication;

[0017] The nitrogen inlet of the gas mixing tank is gated with the nitrogen outlet of the air separation unit, and the nitrogen inlet of the gas mixing tank is gated with the nitrogen output end of the turbine;

[0018] The synthetic ammonia subsystem further comprises a first separation tank and an ammonia tank which are in communication;

[0019] One end of the first heat exchanger is in communication with the ammonia outlet of the reaction tower, and the other end of the first heat exchanger is in communication with the ammonia inlet of the first separation tank.

[0020] Optionally, the ammonia synthesis heat output end of the reaction tower is gated with the heated end of the expander.

[0021] Optionally, the SOEC hydrogen production subsystem comprises a first gas inlet pipeline, a second gas inlet pipeline, a first gas outlet pipeline, a second gas outlet pipeline and a water electrolysis reaction tank;

[0022] The air outlet of the first gas inlet pipeline is in communication with the air inlet of the water electrolysis reaction tank, the water vapor outlet of the second gas inlet pipeline is in communication with the water vapor inlet of the water electrolysis reaction tank; the oxygen outlet of the water electrolysis reaction tank is in communication with the inlet of the first gas outlet pipeline, and the hydrogen outlet of the water electrolysis reaction tank is in communication with the inlet of the second gas outlet pipeline.

[0023] Optionally, the first gas inlet pipeline comprises a second heat exchanger and a second heating device;

[0024] The compressed air outlet of the air separation unit is in communication with the compressed air inlet of the second heat exchanger, the compressed air outlet of the second heat exchanger is in communication with the compressed air inlet of the second heating device, and the compressed air outlet of the second heating device is in communication with the air outlet of the first gas outlet pipeline.

[0025] Optionally, the first gas outlet pipeline comprises a second heat exchanger;

[0026] The oxygen inlet of the second heat exchanger is in communication with the inlet of the first gas outlet pipeline, and the oxygen outlet of the second heat exchanger is in communication with the outlet of the first gas outlet pipeline.

[0027] Optionally, the second gas inlet pipeline comprises a water tank, a peristaltic pump, a water vapor generator, a hydrogen tank and a third heat exchanger;

[0028] The outlet of the water tank is in communication with the inlet of the peristaltic pump, and the outlet of the peristaltic pump is in communication with the liquid inlet of the water vapor generator;

[0029] The outlet of the hydrogen tank is in communication with the first hydrogen inlet of the third heat exchanger, and the first hydrogen outlet of the third heat exchanger is in communication with the gas inlet of the water vapor generator;

[0030] The gas outlet of the water vapor generator is in communication with the water vapor outlet of the second gas inlet pipeline.

[0031] Optionally, the second gas outlet pipeline comprises a third heat exchanger and a second separation tank;

[0032] The second hydrogen inlet of the third heat exchanger is in communication with the inlet of the second gas outlet pipeline, and the second hydrogen outlet of the third heat exchanger is in communication with the inlet of the second separation tank;

[0033] The outlet of the second separation tank is in communication with the hydrogen inlet of the synthetic ammonia subsystem.

[0034] The synthetic ammonia coupling system provided by the embodiments of the present application, the air separation unit is shared by the liquid air energy storage subsystem, the synthetic ammonia subsystem and the SOEC hydrogen production subsystem, which can effectively reduce the equipment cost of the coupling system. The power generation unit in the liquid air energy storage subsystem can adjust the storage and release of the electric energy generated by thermal expansion in combination with the power supply condition of the external electric energy source, meet the electric energy demand of the normal operation of the synthetic ammonia subsystem and the SOEC hydrogen production subsystem, save the electricity cost; the product of the liquid air energy storage subsystem can also be used as the nitrogen source required by the synthetic ammonia subsystem, and the green hydrogen produced by electrolysis of the SOEC hydrogen production subsystem can be used as the hydrogen source required by the synthetic ammonia subsystem to meet the raw material demand of the synthetic ammonia subsystem for synthesizing ammonia gas. Moreover, the ammonia synthesis heat generated by the synthetic ammonia subsystem during the ammonia gas synthesis process can be fully utilized by the power generation unit in the liquid air energy storage subsystem to generate electricity, thereby effectively improving the power generation efficiency. The synthetic ammonia coupling system thus arranged can realize the complementary advantages of the liquid air energy storage subsystem, the synthetic ammonia subsystem and the SOEC hydrogen production subsystem, and effectively improve the energy efficiency.

[0035] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0037] Figure 1 is a structural schematic diagram of a synthetic ammonia coupling system according to an embodiment of the present application;

[0038] Figure 2 is a structural schematic diagram of another synthetic ammonia coupling system according to an embodiment of the present application;

[0039] Figure 3 is a structural schematic diagram of another synthetic ammonia coupling system according to an embodiment of the present application;

[0040] Figure 4 is a structural schematic diagram of another synthetic ammonia coupling system according to an embodiment of the present application. DETAILED DESCRIPTION

[0041] In the following, the technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort should fall within the protection scope of the present application.

[0042] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units need not be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0043] As described in the background, with the rapid growth of intermittent renewable energy such as solar and wind power, the intermittent and volatile power generation shortcoming is highlighted, and the combination of LAES technology and renewable energy power generation system is just a high-quality energy storage means. When the renewable energy power generation system is in the power generation peak period, i.e. power surplus, nitrogen is efficiently compressed and liquefied for storage to realize power storage; when the renewable energy power generation system is in the power generation trough period, i.e. power shortage, liquid nitrogen gasifies and expands to generate power, accurately balances power supply and demand, and eliminates energy fluctuations. At the same time, hydrogen energy is highly regarded due to its clean and efficient characteristics, so SOEC technology is on the rise. Green hydrogen is not only a key driver of energy transformation, but also a potential stock of chemical raw materials. In the field of ammonia synthesis, traditional processes rely on fossil fuels to synthesize ammonia, so carbon emissions are large. Therefore, related technologies use green hydrogen derived from renewable energy to carry out green ammonia synthesis with nitrogen, which is in line with the trend of carbon reduction. And ammonia has high energy density and is easy to liquefy, store and transport, which is an ideal hydrogen carrier and energy storage medium. However, the coupling application of related technologies for LAES technology, SOEC technology and ammonia synthesis technology needs to be improved.

[0044] Based on the above technical problems, the embodiments of the present application provide the following technical solutions:

[0045] The embodiments of the present application provide a synthetic ammonia coupling system. Figure 1 A structural schematic diagram of a synthetic ammonia coupling system provided by the embodiments of the present application is shown in FIG. 1. Figure 1As shown, the synthetic ammonia coupling system 000 includes: a liquid air energy storage subsystem 100, a synthetic ammonia subsystem 200, and a SOEC hydrogen production subsystem 300.

[0046] The liquid air energy storage subsystem 100 includes an air separation unit 110 and a power generation unit 121, a nitrogen gas outlet of the air separation unit 110 is in communication with a nitrogen gas inlet of the power generation unit 121, and the nitrogen gas outlet of the air separation unit 110 is in communication with a nitrogen gas inlet of the synthetic ammonia subsystem 200, and a nitrogen gas outlet of the power generation unit 121 is in communication with the nitrogen gas inlet of the synthetic ammonia subsystem 200; and an electric energy output end of the power generation unit 121 is electrically connected with an electric energy input end of the synthetic ammonia subsystem 200 and the SOEC hydrogen production subsystem 300, respectively.

[0047] A compressed air outlet of the air separation unit 110 is in communication with a compressed air inlet of the SOEC hydrogen production subsystem 300; and a hydrogen gas outlet of the SOEC hydrogen production subsystem 300 is in communication with a hydrogen gas inlet of the synthetic ammonia subsystem 200.

[0048] An ammonia gas synthesis heat output end of the synthetic ammonia subsystem 200 is in communication with an ammonia gas synthesis heat input end of the power generation unit 121.

[0049] Specifically, the liquid air energy storage subsystem 100 in the synthetic ammonia coupling system 000 is used to combine the power supply of an external electric energy source, utilize expansion heat generation at the same time, and adjust the storage or release of electric power in different power supply periods of the external electric energy source. Exemplarily, the external electric energy source can include electric power generated by a renewable energy power generation system such as solar energy and wind energy. The SOEC hydrogen production subsystem 300 is used to generate hydrogen gas, i.e., green hydrogen, by utilizing water vapor electrolysis based on the principle of high-temperature water electrolysis. The synthetic ammonia subsystem 200 is used to mix nitrogen gas and hydrogen gas and synthesize ammonia gas at high temperature by obtaining nitrogen gas and hydrogen gas, so as to achieve the final purpose of generating ammonia gas by the synthetic ammonia coupling system 000, and effectively store the obtained ammonia gas product. In the process of generating ammonia gas by the synthetic ammonia subsystem 200, a certain amount of ammonia gas synthesis heat is generated.

[0050] The liquid air energy storage subsystem 100 is provided with an air separation unit 110 and a power generation unit 121. The air separation unit 110 is used for compressing and separating air to separate nitrogen from the air, so as to facilitate the power generation unit 121 to generate power by using the heat released in the liquefaction process of the nitrogen. The air separation unit 110 can also deliver the nitrogen separated from the air to the synthetic ammonia subsystem 200 as one of the nitrogen sources of the synthetic ammonia subsystem 200; and the air separation unit 110 can also provide compressed air for the SOEC hydrogen production subsystem 300 to drive the oxygen generated in the water electrolysis reaction process to flow. Therefore, the liquid air energy storage subsystem 100, the synthetic ammonia subsystem 200 and the SOEC hydrogen production subsystem 300 share the air separation unit 110, so that the equipment cost of the synthetic ammonia coupling system 000 can be effectively reduced.

[0051] To improve the coupling application of the synthetic ammonia coupling system 000, in the synthetic ammonia coupling system 000 provided by the embodiment of the present application, the liquid air energy storage subsystem 100 can combine the electric energy provided by the external electric energy source including the renewable energy power generation system to allocate the electric energy generated by thermal expansion, so as to effectively balance the power supply while meeting the electric energy demand of the normal operation of the synthetic ammonia subsystem 200 and the SOEC hydrogen production subsystem 300, and guarantee the stable operation of the synthetic ammonia subsystem 200 and the SOEC hydrogen production subsystem 300. The green hydrogen product generated by the operation of the SOEC hydrogen production subsystem 300 can be used as one of the raw materials for synthesizing ammonia gas in the synthetic ammonia subsystem 200, and the products in the synthetic ammonia coupling system 000 can be fully utilized to reduce the purchase demand of hydrogen raw materials required for synthesizing ammonia gas, which is conducive to reducing the production cost. In addition, the synthetic ammonia subsystem 200 can include different nitrogen sources under different conditions. For example, the nitrogen required by the synthetic ammonia subsystem 200 can be obtained by air separation, or can be obtained by the liquid air energy storage subsystem 100, which is not limited herein. In addition, the synthetic ammonia coupling system 000 can also perform unified heat management. The waste heat generated in the operation process of the utilization subsystem, i.e., the ammonia synthesis heat generated in the operation process of the synthetic ammonia subsystem 200, is applied to the thermal expansion process of the power generation unit 121 in the liquid air energy storage subsystem 100. In this way, the tail gas waste heat can be fully utilized, the heat management effect can be improved, and the power generation efficiency of the liquid air energy storage subsystem 100 can also be improved, so as to achieve the effect of synergistic effect. The synthetic ammonia coupling system 000 thus arranged can realize the complementary advantages among the liquid air energy storage subsystem 100, the synthetic ammonia subsystem 200 and the SOEC hydrogen production subsystem 300, and effectively improve the energy efficiency.

[0052] The synthetic ammonia coupling system provided by the embodiments of the present application is provided. The air separation unit is shared by the liquid air energy storage subsystem, the synthetic ammonia subsystem and the SOEC hydrogen production subsystem, which can effectively reduce the equipment cost of the coupling system. The power generation unit in the liquid air energy storage subsystem can be combined with the power supply condition of the external power source to adjust the storage and release of the electric energy generated by thermal expansion, so as to meet the electric energy demand of the normal operation of the synthetic ammonia subsystem and the SOEC hydrogen production subsystem, and save the electricity cost. The product of the liquid air energy storage subsystem can also be used as the nitrogen source required by the synthetic ammonia subsystem, and the green hydrogen produced by the electrolysis of the SOEC hydrogen production subsystem can be used as the hydrogen source required by the synthetic ammonia subsystem, so as to meet the raw material demand of the synthetic ammonia subsystem for synthesizing ammonia gas. In addition, the ammonia synthesis heat generated by the synthetic ammonia subsystem during the ammonia synthesis process can be fully utilized by the power generation unit in the liquid air energy storage subsystem to generate electricity, so as to effectively improve the power generation efficiency. The synthetic ammonia coupling system thus arranged can realize the complementary advantages of the liquid air energy storage subsystem, the synthetic ammonia subsystem and the SOEC hydrogen production subsystem, and effectively improve the energy efficiency.

[0053] On the basis of the above-mentioned embodiments, Figure 2 is a structural schematic diagram of another synthetic ammonia coupling system provided by the embodiments of the present application. Referring to Figure 2 Optionally, the air separation unit 110 comprises an air compressor 111 and an air separation device 112.

[0054] The compressed air outlet of the air compressor 111 is in communication with the compressed air inlet of the air separation device 112, and the nitrogen gas outlet of the air separation device 112 is in communication with the nitrogen gas inlet of the power generation unit 121 and the nitrogen gas inlet of the synthetic ammonia subsystem 200, respectively.

[0055] The compressed air outlet of the air compressor 111 is in communication with the compressed air inlet of the SOEC hydrogen production subsystem 300.

[0056] Specifically, the air compressor 111 is used for compressing air and delivering the compressed air to the air separation device 112. The air separation device 112 is used for separating nitrogen gas from the compressed air and delivering the nitrogen gas to the power generation unit 121 of the liquid air energy storage subsystem 100 for power generation and to the synthetic ammonia subsystem 200 as a nitrogen source. The air side of the SOEC hydrogen production subsystem 300 needs to inject air, so the SOEC hydrogen production subsystem 300 is in communication with the air compressor 111 to obtain air. Therefore, the air separation device 112 is shared by the liquid air energy storage subsystem 100 and the synthetic ammonia subsystem 200, and the air compressor 111 is shared by the liquid air energy storage subsystem 100, the synthetic ammonia subsystem 200 and the SOEC hydrogen production subsystem 300. In this way, part of the equipment is shared by the corresponding subsystems, which can effectively reduce the equipment cost of the synthetic ammonia coupling system 000.

[0057] It should be noted that, for the nitrogen required by the liquid air energy storage subsystem 100 and the ammonia synthesis subsystem 200, in the embodiment of the present application, the nitrogen is obtained by first compressing and separating the air, and then transmitting the pure nitrogen to the corresponding devices of the liquid air energy storage subsystem 100 and the ammonia synthesis subsystem 200. Compared with the air separation to obtain nitrogen in a certain intermediate step in the coupling system in the related art, the embodiment of the present application can reduce the energy loss caused by the complex gas composition, effectively improve the energy conversion efficiency; and the nitrogen is transported as an inert gas in the coupling system, which can prevent the gas from reacting with the devices in the coupling system, such as oxidation, has less corrosion to the devices, is beneficial to prolong the service life of the devices, and reduces the maintenance cost; in addition, the pure nitrogen is introduced, so that the liquefaction or gasification process in the coupling system only involves a single gas. Since the boiling point of the single gas is fixed, the phase change process is easier to control when the gas is cooled or heated, so that the operation stability and controllability of the coupling system are relatively high.

[0058] On the basis of the above embodiments, Figure 3 is another structure schematic diagram of the ammonia synthesis coupling system provided by the embodiment of the present application, Figure 4 is another structure schematic diagram of the ammonia synthesis coupling system provided by the embodiment of the present application. Referring to Figures 2 to 4 Optionally, the power generation unit 121 includes a nitrogen compressor 120, an oil tank 130, a liquid nitrogen storage tank 140, an expander 150, a turbine 160, and a generator 170.

[0059] The nitrogen inlet of the nitrogen compressor 120 is in communication with the nitrogen outlet of the air separation device 112, the heat output end of the nitrogen compressor 120 is in communication with the heat input end of the oil tank 130, and the liquid nitrogen outlet of the nitrogen compressor 120 is in communication with the liquid nitrogen inlet of the liquid nitrogen storage tank 140.

[0060] The liquid nitrogen outlet of the liquid nitrogen storage tank 140 is in communication with one end of the expander 150, the other end of the expander 150 is in communication with one end of the turbine 160, and the other end of the turbine 160 is in communication with the generator 170.

[0061] The heat output end of the oil tank 130 is selected to be in communication with the heated end of the expander 150.

[0062] Specifically, in the power generation unit 121 of the liquid air energy storage subsystem 100, the nitrogen compressor 120, the liquid nitrogen storage tank 140, the expander 150, the turbine 160, and the generator 170 are sequentially communicated and connected downstream of the air separation device 112, so that the compression heat generated in the process of forming liquid nitrogen by compressing nitrogen is used to realize power generation through the expander 150, the turbine 160, and the generator 170.

[0063] The oil tank 130 is connected downstream of the nitrogen compressor 120, and the oil tank 130 and the expander 150 can be selectively connected under different external power supply conditions to ensure the electricity required for normal operation of the synthetic ammonia subsystem 200 and the SOEC hydrogen production subsystem 300. Among them, different external power supply conditions can include the case of excess external power supply and the case of insufficient external power supply.

[0064] Exemplarily, Figure 3 The structure schematic diagram of the synthetic ammonia coupling system during the period of excess external power supply is shown. As Figure 3 As shown, during the period of excess power generated by the renewable energy power generation system, the nitrogen separated by the air separation device 112 enters the nitrogen compressor 120, and the compressed and cooled nitrogen is stored in the liquid nitrogen storage tank 140. Because during the period of excess green electricity provided by the external power generation system, the synthetic ammonia coupling system 000 can use green electricity to keep each subsystem stable, and does not need to generate more electricity to supply each subsystem, therefore, the heat generated during the compression of nitrogen in the nitrogen compressor 120 can be transmitted to the oil tank 130, the heat generated by the compressed nitrogen is stored in the oil tank 130 by heating the oil to obtain hot oil, and the nitrogen stored in the liquid nitrogen storage tank 140 does not continue to transmit to the expander 150, the turbine 160 and the generator 170 to generate electricity, so that the liquid air energy storage subsystem 100 realizes power storage during the period of excess external power supply. Therefore, during the period of excess external power supply, the oil tank 130 and the expander 150 are not connected.

[0065] Exemplarily, Figure 4 The structure schematic diagram of the synthetic ammonia coupling system during the period of insufficient external power supply is shown. As Figure 4As shown, during the period when the electric energy generated by the renewable energy power generation system is insufficient, the electric energy demand of each subsystem cannot be met by the external electric energy alone, and therefore, the oil tank 130 is communicated with the expander 150 during the period when the external power supply is insufficient. At this time, the heat of the hot oil stored in the oil tank 130 during the period when the external power supply is excessive can be transmitted to the expander 150 through the heated end of the expander 150; at the same time, the liquid nitrogen stored in the liquid nitrogen storage tank 140 is also delivered to the expander 150, and the ammonia synthesis heat generated in the process of synthesizing ammonia gas by the ammonia synthesis subsystem 200 is also delivered to the expander 150, so as to expand and then enter the turbine 160 and the generator 170 to generate electric energy. The generated electric energy can be transmitted to the ammonia synthesis subsystem 200 and the SOEC hydrogen production subsystem 300, so as to fully utilize the waste heat and ensure the stable operation of the ammonia synthesis subsystem 200 and the SOEC hydrogen production subsystem 300 during the period when the electric energy generated by the renewable energy power generation system is insufficient, thereby relieving the pressure of the external heat supply demand of the liquid air energy storage subsystem 100; at the same time, if the electric energy generated by the external power supply and the liquid air energy storage subsystem 100 is still excessive after being applied to the ammonia synthesis subsystem 200 and the SOEC hydrogen production subsystem 300, the surplus electric energy can be integrated into the power grid, thereby further reducing the electricity cost. In this way, the liquid air energy storage subsystem 100 can be flexibly arranged for power allocation, effectively ensuring the normal operation of the ammonia synthesis subsystem 200 and the SOEC hydrogen production subsystem 300 during the period when the electric energy generated by the renewable energy power generation system is insufficient, and effectively saving the electricity cost.

[0066] On the basis of the above-mentioned embodiments, continuing to refer to Figure 3 and Figure 4 Optionally, the ammonia synthesis subsystem 200 comprises, in sequence, a gas mixing tank 210, a mixed gas compressor 220, a first heat exchanger 230, a first heating device 240 and a reaction tower 250.

[0067] The nitrogen gas inlet of the gas mixing tank 210 is selected to be communicated with the nitrogen gas outlet of the air separation unit 110, and the nitrogen gas inlet of the gas mixing tank 210 is selected to be communicated with the nitrogen gas output end of the turbine 160.

[0068] The ammonia synthesis subsystem 200 further comprises a first separation tank 260 and an ammonia gas tank 270 which are communicated; one end of the first heat exchanger 230 is communicated with the ammonia gas outlet of the reaction tower 250, and the other end of the first heat exchanger 230 is communicated with the ammonia gas inlet of the first separation tank 260.

[0069] Specifically, the gas mixing tank 210 is used to mix the obtained nitrogen and hydrogen obtained by the SOEC hydrogen production subsystem 300, and then the mixed nitrogen and hydrogen are compressed by the mixed gas compressor 220, and then the temperature of the mixed nitrogen and hydrogen is balanced by the first heat exchanger 230, and then the mixed nitrogen and hydrogen are delivered to the first heating device 240 for heating, and finally enter the reaction tower 250 for ammonia synthesis reaction to generate ammonia. For different power consumption periods, the nitrogen source of the gas mixing tank 210 is different. For example, during the period of excess external power supply, referring to Figure 3 , the gas mixing tank 210 is in communication with the air separation device 112 to compress the separated nitrogen in the compressed air as the nitrogen source; during the period of insufficient external power supply, referring to Figure 4 , the gas mixing tank 210 is in communication with the turbine 160 in the liquid air energy storage subsystem 100, and after the power generation unit 121 generates electricity, the nitrogen released by the turbine 160 is used as the nitrogen source. In this way, the products of the subsystem can be fully utilized, and the storage and transportation cost of the ammonia synthesis raw materials is reduced.

[0070] After the ammonia gas is generated by the ammonia synthesis reaction in the reaction tower 250, the ammonia gas is delivered to the first heat exchanger 230 for cooling, and then the ammonia gas is transmitted to the first separation tank 260 to separate part of the nitrogen and / or hydrogen raw materials mixed in the generated ammonia gas, and high-purity ammonia gas is obtained; and then the high-purity ammonia gas is delivered to the ammonia tank 270 for storage and transportation.

[0071] Based on the above embodiments, referring to Figure 4 , optionally, the ammonia synthesis heat output end of the reaction tower 250 is selected to communicate with the heated end of the expander 150.

[0072] Specifically, ammonia synthesis heat is generated during the ammonia synthesis reaction in the reaction tower 250. During the period of insufficient external power supply, by communicating the reaction tower 250 with the expander 150, the ammonia synthesis heat generated in the ammonia synthesis reaction is delivered from the reaction tower 250 to the expander 150 of the liquid air energy storage subsystem 100, so as to fully utilize the waste heat of the ammonia synthesis subsystem 200 to generate electricity through the turbine 160 and the generator 170, so as to ensure the required power for the normal operation of the ammonia synthesis coupled system 000. During the period of excess external power supply, the liquid air energy storage subsystem 100 does not need to utilize the waste heat to generate electricity to maintain the normal operation of other subsystems, and therefore, the reaction tower 250 and the expander 150 are not in communication. By selectively communicating the reaction tower 250 and the expander 150, the ammonia synthesis heat can be fully utilized to ensure the normal operation of the ammonia synthesis coupled system 000.

[0073] Based on the above embodiments, referring to Figure 3Optionally, the SOEC hydrogen production subsystem 300 comprises a first air inlet pipeline, a second air inlet pipeline, a first gas outlet pipeline, a second gas outlet pipeline and an electrolytic water reaction tank 330.

[0074] The air outlet of the first air inlet pipeline is in communication with the air inlet of the electrolytic water reaction tank 330, and the water vapor outlet of the second air inlet pipeline is in communication with the water vapor inlet of the electrolytic water reaction tank 330; the oxygen outlet of the electrolytic water reaction tank 330 is in communication with the inlet of the first gas outlet pipeline, and the hydrogen outlet of the electrolytic water reaction tank 330 is in communication with the inlet of the second gas outlet pipeline.

[0075] Specifically, the air side of the electrolytic water reaction tank 330 is in communication with the first air inlet pipeline and the first gas outlet pipeline. The first air inlet pipeline is used to input air into the electrolytic water reaction tank 330; the first gas outlet pipeline is used to make the oxygen generated in the electrolytic water process flow with the air and be discharged from the oxygen outlet of the electrolytic water reaction tank 330. The fuel side of the electrolytic water reaction tank 330 is in communication with the second air inlet pipeline and the second gas outlet pipeline. The second air inlet pipeline is used to input the fuel required for electrolytic water, i.e. water vapor, into the electrolytic water reaction tank 330, so as to generate green hydrogen in the electrolytic water reaction tank 330; the second gas outlet pipeline is used to discharge the hydrogen generated in the electrolytic water reaction tank 330 from the hydrogen outlet. It should be noted that, Figure 3 and Figure 4 The first air inlet pipeline, the second air inlet pipeline, the first gas outlet pipeline and the second gas outlet pipeline are not marked and described in the above-mentioned embodiments. The specific components included in each of the first air inlet pipeline, the second air inlet pipeline, the first gas outlet pipeline and the second gas outlet pipeline are described in the following embodiments to show the gas flow direction in each gas pipeline.

[0076] Based on the above-mentioned embodiments, the following embodiments are continued to be described with reference to Figure 3 or Figure 4 Optionally, the first air inlet pipeline comprises a second heat exchanger 311 and a second heating device 312; the compressed air outlet of the air separation unit 110 is in communication with the compressed air inlet of the second heat exchanger 311, the compressed air outlet of the second heat exchanger 311 is in communication with the compressed air inlet of the second heating device 312, and the compressed air outlet of the second heating device 312 is in communication with the air outlet of the first air inlet pipeline.

[0077] Specifically, in the first air inlet pipeline on the air side of the SOEC hydrogen production subsystem 300, the air compressor 111 is in communication with the second heat exchanger 311 to deliver the compressed air to the second heat exchanger 311 for temperature balancing, and then the second heating device 312 is used to heat the compressed air, which is delivered to the electrolytic water reaction tank 330.

[0078] Based on the above-mentioned embodiments, the following embodiments are continued to be described with reference to Figure 3 orFigure 4 Optionally, the first gas outlet pipeline comprises a second heat exchanger 311.

[0079] The oxygen inlet of the second heat exchanger 311 is in communication with the inlet of the first gas outlet pipeline; the oxygen outlet of the second heat exchanger 311 is in communication with the outlet of the first gas outlet pipeline.

[0080] Specifically, in the first gas outlet pipeline on the air side of the SOEC hydrogen production sub-system 300, the oxygen outlet of the water electrolysis reaction tank 330 is in communication with the oxygen inlet of the second heat exchanger 311. The oxygen generated by the water electrolysis reaction in the water electrolysis reaction tank 330 flows out of the oxygen outlet of the water electrolysis reaction tank 330 by the air input into the water electrolysis reaction tank 330. The outflowing oxygen is cooled by the second heat exchanger 311, and then can be directly output to the external environment or reused, which is not limited herein.

[0081] Based on the above embodiments, further referring to Figure 3 or Figure 4 Optionally, the second gas inlet pipeline comprises a water tank 321, a peristaltic pump 322, a water vapor generator 323, a hydrogen tank 324 and a third heat exchanger 325.

[0082] The outlet of the water tank 321 is in communication with the inlet of the peristaltic pump 322, and the outlet of the peristaltic pump 322 is in communication with the liquid inlet of the water vapor generator 323; the outlet of the hydrogen tank 324 is in communication with the first hydrogen inlet of the third heat exchanger 325, and the first hydrogen outlet of the third heat exchanger 325 is in communication with the gas inlet of the water vapor generator 323; the gas outlet of the water vapor generator 323 is in communication with the water vapor outlet of the second gas inlet pipeline.

[0083] Specifically, in the second gas inlet pipeline on the fuel side of the SOEC hydrogen production sub-system 300, the water stored in the water tank 321 is accurately and quantitatively delivered to the water vapor generator 323 by the peristaltic pump 322 to generate water vapor in liquid form. At the same time, the hydrogen stored in the hydrogen tank 324 is transmitted in the form of a small flow of gas, and after temperature balance by the third heat exchanger 325, it is transmitted to the water vapor generator 323 to deliver the water vapor into the water electrolysis reaction tank 330 as a transmission carrier without introducing other new gas impurities; at the same time, the hydrogen transmitted into the water electrolysis reaction tank 330 also plays a role of reducing the fuel electrode, i.e., the hydrogen can inhibit the oxidation of water vapor at high temperature.

[0084] Based on the above embodiments, further referring to Figure 3 or Figure 4 Optionally, the second gas outlet pipeline comprises a third heat exchanger 325 and a second separation tank 340.

[0085] The second hydrogen inlet of the third heat exchanger 325 is in communication with the inlet of the second gas outlet pipeline, and the second hydrogen outlet of the third heat exchanger 325 is in communication with the inlet of the second separation tank 340; the outlet of the second separation tank 340 is in communication with the hydrogen inlet of the ammonia synthesis subsystem 200.

[0086] Specifically, after the water electrolysis reaction in the water electrolysis reaction tank 330 is completed to obtain hydrogen, the hydrogen is output from the water electrolysis reaction tank 330 to the third heat exchanger 325 for cooling, and then the cooled hydrogen is directly input into the second separation tank 340 to separate and purify the green hydrogen. In the ammonia synthesis coupling system 000 provided in the embodiment of the present application, the high-purity hydrogen obtained by the SOEC hydrogen production subsystem 300 is directly transported to the gas mixing tank 210 of the ammonia synthesis subsystem 200 to serve as the only hydrogen source for the ammonia synthesis reaction, thereby reducing the ammonia synthesis raw material storage and transportation cost and also solving the hydrogen storage and transportation difficulty.

[0087] The above specific embodiments do not constitute a limitation on the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A synthetic ammonia coupling system, characterized in that, include: Liquid air energy storage subsystem, ammonia synthesis subsystem, and SOEC hydrogen production subsystem; The liquid air energy storage subsystem includes an air separation unit and a power generation unit. The nitrogen outlet of the air separation unit is connected to the nitrogen inlet of the power generation unit, and the nitrogen outlet of the air separation unit is connected to the nitrogen inlet of the ammonia synthesis subsystem. The nitrogen outlet of the power generation unit is also connected to the nitrogen inlet of the ammonia synthesis subsystem. The power output terminal of the power generation unit is electrically connected to the power input terminals of the ammonia synthesis subsystem and the SOEC hydrogen production subsystem, respectively. The compressed air outlet of the air separation unit is connected to the compressed air inlet of the SOEC hydrogen production subsystem; the hydrogen outlet of the SOEC hydrogen production subsystem is connected to the hydrogen inlet of the ammonia synthesis subsystem. The ammonia synthesis heat output terminal of the ammonia synthesis subsystem is connected to the ammonia synthesis heat input terminal of the power generation unit.

2. The ammonia synthesis coupling system according to claim 1, characterized in that, The air separation unit includes an air compressor and an air separation device; The compressed air outlet of the air compressor is connected to the compressed air inlet of the air separator, and the nitrogen outlet of the air separator is connected to the nitrogen inlet of the power generation unit and the nitrogen inlet of the ammonia synthesis subsystem, respectively. The compressed air outlet of the air compressor is connected to the compressed air inlet of the SOEC hydrogen production subsystem.

3. The ammonia synthesis coupling system according to claim 2, characterized in that, The power generation unit includes a nitrogen compressor, an oil tank, a liquid nitrogen storage tank, an expander, a turbine, and a generator; The nitrogen inlet of the nitrogen compressor is connected to the nitrogen outlet of the air separator, the heat output end of the nitrogen compressor is connected to the heat input end of the oil tank, and the liquid nitrogen outlet of the nitrogen compressor is connected to the liquid nitrogen inlet of the liquid nitrogen storage tank. The liquid nitrogen outlet of the liquid nitrogen storage tank is connected to one end of the expander, the other end of the expander is connected to one end of the turbine, and the other end of the turbine is connected to the generator; The heat output end of the oil tank is connected to the heat receiving end of the expander.

4. The ammonia synthesis coupling system according to claim 3, characterized in that, The ammonia synthesis subsystem includes a gas mixing tank, a mixed gas compressor, a first heat exchanger, a first heating device, and a reaction tower connected in sequence. The nitrogen inlet of the mixing tank is connected to the nitrogen outlet of the air separation unit, and the nitrogen inlet of the mixing tank is connected to the nitrogen output end of the turbine. The ammonia synthesis subsystem also includes a first separation tank and an ammonia tank connected together. One end of the first heat exchanger is connected to the ammonia outlet of the reaction tower, and the other end of the first heat exchanger is connected to the ammonia inlet of the first separation tank.

5. The ammonia synthesis coupling system according to claim 4, characterized in that, The ammonia synthesis heat output end of the reaction tower is connected to the heating end of the expander.

6. The ammonia synthesis coupling system according to claim 1, characterized in that, The SOEC hydrogen production subsystem includes a first inlet pipeline, a second inlet pipeline, a first outlet pipeline, a second outlet pipeline, and a water electrolysis reactor. The air outlet of the first air inlet pipe is connected to the air inlet of the water electrolysis reactor, and the water vapor outlet of the second air inlet pipe is connected to the water vapor inlet of the water electrolysis reactor; the oxygen outlet of the water electrolysis reactor is connected to the inlet of the first air outlet pipe, and the hydrogen outlet of the water electrolysis reactor is connected to the inlet of the second air outlet pipe.

7. The ammonia synthesis coupling system according to claim 6, characterized in that, The first intake pipe includes a second heat exchanger and a second heating device; The compressed air outlet of the air separation unit is connected to the compressed air inlet of the second heat exchanger, the compressed air outlet of the second heat exchanger is connected to the compressed air inlet of the second heating device, and the compressed air outlet of the second heating device is connected to the air outlet of the first air inlet pipe.

8. The ammonia synthesis coupling system according to claim 6, characterized in that, The first outlet pipeline includes a second heat exchanger; The oxygen inlet of the second heat exchanger is connected to the inlet of the first outlet pipeline; the oxygen outlet of the second heat exchanger is connected to the outlet of the first outlet pipeline.

9. The ammonia synthesis coupling system according to claim 8, characterized in that, The second intake pipeline includes a water tank, a peristaltic pump, a steam generator, a hydrogen tank, and a third heat exchanger; The outlet of the water tank is connected to the inlet of the peristaltic pump, and the outlet of the peristaltic pump is connected to the liquid inlet of the steam generator. The outlet of the hydrogen tank is connected to the first hydrogen inlet of the third heat exchanger, and the first hydrogen outlet of the third heat exchanger is connected to the gas inlet of the steam generator. The gas outlet of the steam generator is connected to the steam outlet of the second air inlet pipe.

10. The ammonia synthesis coupling system according to claim 9, characterized in that, The second outlet pipeline includes a third heat exchanger and a second separator. The second hydrogen inlet of the third heat exchanger is connected to the inlet of the second outlet pipeline, and the second hydrogen outlet of the third heat exchanger is connected to the inlet of the second separator. The outlet of the second separator is connected to the hydrogen inlet of the ammonia synthesis subsystem.

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