Wind, light and fire storage integrated energy system with ammonia electricity production and carbon capture functions

Abstract

The invention relates to the technical field of energy systems, and provides a wind-light-fire storage integrated energy system with ammonia electricity production and carbon capture functions, which comprises a photovoltaic wind power generation system, a liquid air energy storage system, an electrolyzed water system, an ammonia synthesis system, a heat reservoir and a pure oxygen coal-fired power generation system. The photovoltaic and wind power generation system can integrate photovoltaic, wind power generation, liquid air energy storage, water electrolysis hydrogen production, ammonia synthesis and carbon capture technologies, can operate in three modes of sufficient power generation, insufficient power generation and power failure of the photovoltaic and wind power generation system, and improves the utilization rate and operation efficiency of equipment.

Description

Integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture capabilities Technical Field

[0001] This invention relates to the field of energy system technology, and in particular to an integrated wind, solar, thermal and energy storage system with ammonia power generation and carbon capture functions. Background Technology

[0002] With the intensification of global climate change, the development of clean energy has become a global consensus. Wind and solar energy, with their advantages of being clean, sustainable, widely distributed, and technologically mature, have become core drivers of my country's energy transition. However, influenced by natural factors and user electricity consumption behavior, the power system experiences significant random fluctuations in supply and demand on both the power generation and demand sides, posing a severe challenge to the effective utilization of power resources and the stable operation of the power grid. Energy storage technology, as one of the key technologies for solving the problem of random fluctuations, has broken through the bottleneck of real-time balance in traditional power systems and is an important means to achieve multi-energy integration and cross-energy network collaborative optimization.

[0003] Existing energy storage technologies are mainly classified into five categories: mechanical energy storage (liquid air energy storage, pumped hydro energy storage), electrical energy storage (supercapacitors), electrochemical energy storage (batteries), thermal energy storage (molten salt energy storage), and chemical energy storage (hydrogen energy storage). Among them, liquid air energy storage (LAES) and hydrogen energy storage are large-scale, environmentally friendly, and highly scalable, capable of meeting long-term energy storage needs and have the potential for widespread application in clean energy systems. However, both technologies have certain limitations: due to the small mass, low density, and high heat capacity of air, liquid air energy storage has a low energy density. In addition, the energy storage process involves multiple energy conversion stages, including compression, liquefaction, storage, regasification, and energy release, resulting in a slow response speed. Hydrogen energy storage, on the other hand, produces hydrogen through water electrolysis, using hydrogen as an energy carrier for storage and transportation, which is costly and challenging. Combining liquid air energy storage with hydrogen energy storage, using ammonia synthesis technology to convert hydrogen into ammonia for storage and transportation, can effectively reduce costs. Furthermore, the use of ammonia gas turbines and oxygen obtained through air separation and water electrolysis for pure oxy-fuel coal-fired power generation improves the system's energy density and stability. Finally, carbon capture and recovery of carbon dioxide generated during pure oxy-fuel coal-fired power generation reduces emissions and enables integrated wind, solar, thermal, and energy storage operations, ensuring power system stability while improving the utilization rate of renewable energy.

[0004] Existing energy storage technologies can be divided into three categories: the first category is standalone hydrogen energy storage or liquid air energy storage technology; the second category is a coupled system of hydrogen energy storage and liquid air energy storage; and the third category is a synthetic ammonia energy storage system based on hybrid hydrogen production and air separation.

[0005] The first type of energy storage technology, for standalone hydrogen energy storage systems, faces challenges due to the low density of hydrogen at normal temperature and pressure. Compressing hydrogen to high pressure or converting it into a liquid state for storage is necessary, but high-pressure energy storage equipment is costly and requires significant energy consumption. Furthermore, hydrogen as an energy carrier presents significant storage and transportation difficulties and high costs. Standalone liquid air energy storage involves multiple energy conversion processes, including compression, liquefaction, storage, regasification, and energy release. However, liquid air energy storage suffers from slow response and low energy density.

[0006] The second type of energy storage technology involves a coupled system of hydrogen and liquid air energy storage. This system utilizes hydrogen power generation to increase the system's energy density, leading to increased hydrogen demand, increased hydrogen storage capacity, and increased material costs and cooling requirements for liquefied hydrogen. While hydrogen power generation (fuel cells, gas turbines) improves system energy density, it also places higher demands on hydrogen storage, increasing storage costs. Furthermore, the industrial cooling source required for liquefied hydrogen storage also imposes certain limitations on system site selection.

[0007] The third type of energy storage technology solution is the synthetic ammonia energy storage system based on hybrid hydrogen production and air separation. Since synthetic ammonia and hydrogen production equipment require a stable power supply, additional energy storage devices are needed to balance the fluctuations in wind and solar power generation. Adding small energy storage devices such as batteries cannot achieve long-term energy storage, while adding large energy storage devices, such as pumped hydro storage or fuel cells, increases system complexity. Without energy storage devices, the system relies on the power grid to meet stable power demand, making it unsuitable for isolated areas or other off-grid locations. Synthetic ammonia systems and hydrogen production typically depend on a stable power supply, requiring additional energy storage devices to balance the fluctuations in wind and solar power generation and ensure power supply stability. This increases costs and system complexity, and also limits the applicability due to the inability to achieve long-term energy storage. Summary of the Invention

[0008] This invention mainly addresses the aforementioned technical problems of the three existing energy storage technologies, and proposes an integrated wind-solar-thermal-storage energy system with ammonia-electricity production and carbon capture functions. It integrates photovoltaic, wind power generation, liquid air energy storage, water electrolysis for hydrogen production, ammonia synthesis, and carbon capture technologies, and can operate in three modes: sufficient power generation, insufficient power generation, and power outage, thereby improving the utilization rate and operating efficiency of the equipment.

[0009] This invention provides an integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions, comprising: a photovoltaic wind power generation system, a liquid air energy storage system, a water electrolysis system, a synthetic ammonia system, a thermal storage device, and a pure oxygen coal-fired power generation system;

[0010] The liquid air energy storage system includes a cryogenic air separation subsystem and an energy release subsystem; the cryogenic air separation subsystem includes an air purification unit, an air compression unit, and an air separation unit.

[0011] The cryogenic air separation subsystem separates and liquefies nitrogen and oxygen in the air, storing them in the liquid oxygen storage tank and liquid nitrogen storage tank of the energy release subsystem, respectively. The heat generated by multi-stage compression is stored in the heat storage tank.

[0012] The energy release subsystem includes an energy release subsystem liquid nitrogen storage tank, an energy release subsystem liquid oxygen storage tank, an energy release subsystem pump, an energy release subsystem heat exchanger, and a turbine; the energy release subsystem liquid nitrogen and liquid oxygen storage tanks, the energy release subsystem pump, the energy release subsystem heat exchanger, and the turbine are connected in sequence.

[0013] Preferably, the photovoltaic wind power generation system includes multiple sets of photovoltaic power generation devices and / or multiple sets of wind power generation devices.

[0014] Preferably, the air purification unit includes a first molecular sieve adsorption tower T-301A and a second molecular sieve adsorption tower T-301B;

[0015] The input ends of the first molecular sieve adsorption tower T-301A and the second molecular sieve adsorption tower T-301B are connected to the bottom switching valve group V-101, and the output ends are connected to the top switching valve group V-102; the bottom switching valve group V-101 is connected to the atmospheric environment.

[0016] Preferably, the air compression unit includes a main circuit and a loop;

[0017] The main circuit includes a first compressor C-101, a second compressor C-102, a third compressor C-103, a first intermediate heat exchanger E-101, a second intermediate heat exchanger E-102, and a third intermediate heat exchanger E-103; the first compressor C-101, the first intermediate heat exchanger E-101, the second main circuit compressor C-102, the second intermediate heat exchanger E-102, the third compressor C-103, and the third intermediate heat exchanger E-103 are connected in sequence; the first compressor C-101 is connected to the tower top switching valve group V-102 of the air purification unit; and the outlet of the third intermediate heat exchanger E-103 is connected to the diversion valve V-103 of the air separation unit.

[0018] The circuit includes a fourth compressor C-104, a fourth heat exchanger E-104, a first circulating fan P-101, a diverter valve V-105, and a confluence valve V-106;

[0019] The confluence valve V-106, the fourth compressor C-104, the fourth heat exchanger E-104, the first circulating fan P-101, and the diversion valve V-105 are connected in sequence. The diversion valve V-105 is connected to the first intermediate heat exchanger E-101, the second intermediate heat exchanger E-102, and the third intermediate heat exchanger E-103. The first intermediate heat exchanger E-101, the second intermediate heat exchanger E-102, and the third intermediate heat exchanger E-103 are connected to the confluence valve V-106.

[0020] A first intermediate pressure point B-101 is provided between the first compressor C-101 and the first heat exchanger E-101; a second intermediate pressure point B-102 is provided between the second compressor C-102 and the second heat exchanger E-102; and a third intermediate pressure point B-103 is provided between the third compressor C-103 and the third heat exchanger E-103.

[0021] Preferably, the air separation unit includes a regulating valve V-103, a first expander C-201, a second expander C-202, a main heat exchanger E-201, a high-pressure distillation column T-201, a low-pressure distillation column T-202, a condenser-reboiler E-202, and an argon distillation column T-203;

[0022] The inlet end of the regulating valve V-103 is connected to the high-pressure, ambient-temperature air outlet of the air compression section heat exchanger E-103. The outlet end is divided into three paths. The first path is connected to the first expander C-201 and the second expander C-202 for two-stage expansion before entering the low-pressure distillation tower T-202.

[0023] The second path connects to the main heat exchanger E-201, where liquid nitrogen and liquid oxygen provide cooling. After cooling the high-pressure air, it enters the expander C-202 for expansion, depressurization, and cooling, and is then fed into the low-pressure distillation column T-202.

[0024] The third line connects to the main heat exchanger E-201 for cryogenic cooling, and then flows into the high-pressure distillation column T-201.

[0025] Preferably, the water electrolysis system includes a water electrolysis unit, a compressor, a hydrogen storage tank for the water electrolysis system, and an oxygen storage tank for the water electrolysis system.

[0026] Preferably, the ammonia synthesis system adopts the HB ammonia synthesis process, and the ammonia synthesis system includes an ammonia synthesis reactor, an ammonia storage tank, a liquid ammonia pump, a heat exchanger for the ammonia synthesis system, and an ammonia gas turbine.

[0027] Preferably, the heat storage device includes a phase change material or a thermal oil tank, and the input end of the heat storage device is connected to the air cryogenic separation subsystem, the HB ammonia synthesis system, and the water electrolysis system, respectively.

[0028] Preferably, the pure oxygen coal-fired power generation system includes a boiler and a carbon capture device; oxygen from the oxygen storage tank of the water electrolysis system and treated coal powder are introduced into the boiler; the boiler's outlet is connected to the carbon capture device, and the generated carbon dioxide is recovered by the carbon capture device.

[0029] Preferably, the integrated wind-solar-thermal-storage energy system with ammonia power generation and carbon capture functions has three operating modes: sufficient photovoltaic and wind power generation, insufficient power generation, and power outage.

[0030] When the photovoltaic and wind power generation system generates sufficient electricity, it supplies power to the cryogenic air separation subsystem and the water electrolysis system. The cryogenic air separation subsystem separates air into liquid nitrogen and liquid oxygen through air purification, air compression, and air separation, and stores them. The water electrolysis system produces hydrogen and oxygen, which are stored in the hydrogen storage tank and oxygen storage tank of the water electrolysis system, respectively. The heat generated by the multi-stage compression of the cryogenic air separation subsystem, the ammonia synthesis system, and the water electrolysis system is stored in a heat storage tank. After the liquid nitrogen is pressurized by the pump of the energy release subsystem, it absorbs the heat in the heat storage tank and is converted into a high-temperature and high-pressure gas, which enters the HB ammonia synthesis reactor with the hydrogen produced by the water electrolysis to produce liquid ammonia.

[0031] When the photovoltaic and wind power generation systems generate insufficient power, they only supply power to the cryogenic air separation subsystem and the water electrolysis system. The remaining power is supplied by liquid air energy storage, a pure oxygen coal-fired power generation system, an ammonia gas turbine, or the power grid. The cryogenic air separation subsystem separates air into liquid nitrogen and liquid oxygen and stores them. Electrolysis of water produces hydrogen and oxygen and stores them. The heat generated by the multi-stage compression of the cryogenic air separation subsystem, ammonia synthesis, and the water electrolysis system is stored in a thermal storage tank. After the liquid nitrogen and liquid oxygen are pressurized by a pump, they absorb the heat generated by the thermal storage tank or the ammonia synthesis system and are converted into high-temperature and high-pressure gases to drive an expander to generate electricity, meeting the electricity needs of the cryogenic air separation subsystem, the water electrolysis system, and users. The nitrogen after expansion and depressurization and the hydrogen produced by water electrolysis are used to synthesize ammonia, which generates electricity through an ammonia gas turbine. After the oxygen is expanded and depressurized, it is combined with the oxygen produced by the water electrolysis system for pure oxygen combustion to generate electricity. The carbon dioxide produced is collected and utilized by a carbon capture device.

[0032] When the photovoltaic and wind power generation systems lose power, the cryogenic air separation subsystem stops working. The water electrolysis system is powered by liquid air energy storage, a pure oxygen coal-fired power generation system, an ammonia gas turbine, or the power grid. The heat generated by the water electrolysis and ammonia synthesis systems is stored in a thermal storage tank. The liquid nitrogen and liquid oxygen in the storage tank are pressurized by a pump and then absorb the heat generated by the thermal storage tank or the ammonia synthesis system, converting them into high-temperature and high-pressure gases to drive an expander to generate electricity, meeting the electricity needs of the water electrolysis system and users. After the nitrogen expands and depressurizes, it enters the ammonia synthesis reactor with the hydrogen generated by the water electrolysis system to produce liquid ammonia, which generates electricity through an ammonia gas turbine. After the oxygen expands and depressurizes, it undergoes pure oxygen combustion with the oxygen generated by the water electrolysis system to generate electricity. The carbon dioxide produced is collected and utilized by a carbon capture device.

[0033] This invention provides an integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions. Addressing the random fluctuations in photovoltaic and wind power generation as well as user electricity consumption, and combining liquefied air, hydrogen energy storage, synthetic ammonia, and carbon capture technologies, it offers the following advantages:

[0034] 1. High-efficiency utilization of renewable energy: This system integrates photovoltaic, wind power generation, liquefied gas energy storage, water electrolysis for hydrogen production, ammonia synthesis, and carbon capture technologies. Under the random fluctuations of photovoltaic and wind power generation and user electricity consumption, the system can operate in three modes: sufficient power generation, insufficient power generation, and power outage, according to the priority principle of the system operation design. It can be connected to the grid or operate independently of the grid, which improves the utilization rate and operating efficiency of the equipment.

[0035] 2. Long-term energy storage: Liquid air energy storage enables long-term power storage, solving the problem of limited battery energy storage time.

[0036] 3. High energy density and response speed: When wind and photovoltaic power generation is insufficient or completely cut off, the system couples three power supply modes: liquid air energy storage, pure oxygen coal combustion, and ammonia gas turbine. Even when the system is off-grid, it still has high energy density and response speed.

[0037] 4. Low cost: By using synthetic ammonia technology and liquid air energy storage liquid, hydrogen generated by water electrolysis is converted into ammonia for storage and transportation. This reduces costs while enabling long-term energy storage and improves the system's economic efficiency.

[0038] 5. Low energy dissipation: The system is equipped with a separate heat storage device to recover the heat generated by the ASU multi-stage compression, ammonia synthesis, and water electrolysis system, which is used for heating and vaporizing liquid nitrogen and liquid oxygen, thus reducing the system's energy dissipation.

[0039] 6. Environmental protection: The system integrates carbon capture technology, which not only makes efficient use of renewable energy, but also further reduces carbon emissions. Attached Figure Description

[0040] Figure 1 is a schematic diagram of the integrated wind, solar, thermal and energy storage energy system with ammonia power generation and carbon capture functions provided by the present invention.

[0041] Figure 2 is a schematic diagram of the air cryogenic separation subsystem provided by the present invention;

[0042] Figure 3 is a diagram of the system operation mode when the photovoltaic and wind power generation system generates sufficient electricity;

[0043] Figure 4 is a diagram of the system operation mode when the photovoltaic and wind power generation systems are underpowered.

[0044] Figure 5 shows the system operation mode when the photovoltaic and wind power generation system experiences a power outage. Detailed Implementation

[0045] To make the technical problems solved by this invention, the technical solutions adopted, and the technical effects achieved clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings, not all of them.

[0046] As shown in Figure 1, the integrated wind-solar-thermal-storage energy system with ammonia-electricity production and carbon capture functions provided in this embodiment of the invention includes: a photovoltaic wind power generation system, a liquid air energy storage system, a water electrolysis system, a synthetic ammonia system, a thermal storage device, and a pure oxygen coal-fired power generation system.

[0047] The photovoltaic-wind power generation system includes multiple sets of photovoltaic power generation devices and / or multiple sets of wind power generation devices. The photovoltaic power generation devices convert solar energy into electrical energy and can be connected to the grid or operate independently. The wind power generation devices convert wind energy into electrical energy and can be connected to the grid or operate independently.

[0048] The liquid air energy storage system includes an air cryogenic separation subsystem (ASU) and an energy release subsystem.

[0049] The air cryogenic separation subsystem comprises three units: an air purification unit, an air compression unit, and an air separation unit.

[0050] As shown in Figure 2, the air purification unit includes a first molecular sieve adsorption tower T-301A and a second molecular sieve adsorption tower T-301B. The two adsorption towers operate alternately, with one adsorbing online and the other regenerating offline. The input ends of the first molecular sieve adsorption tower T-301A and the second molecular sieve adsorption tower T-301B are connected to the bottom switching valve group V-101, and the output ends are connected to the top switching valve group V-102. The bottom switching valve group V-101 is connected to the atmospheric environment. The air purification unit is used to adsorb water vapor, carbon dioxide, and trace hydrocarbon impurities in the air.

[0051] The air compression unit includes a main circuit and a secondary circuit. The main circuit includes a first compressor C-101, a second compressor C-102, a third compressor C-103, a first intermediate heat exchanger E-101, a second intermediate heat exchanger E-102, and a third intermediate heat exchanger E-103. These components are connected sequentially. The first compressor C-101 is connected to the top switching valve group V-102 of the air purification unit, and the outlet of the third intermediate heat exchanger E-103 is connected to the diversion valve V-103 of the air separation unit. The main circuit compresses and cools the air output from the air purification unit through multiple stages to produce high-pressure, room-temperature gas for air separation.

[0052] The circuit includes a fourth compressor C-104, a fourth heat exchanger E-104, a first circulating fan P-101, a diverter valve V-105, and a confluence valve V-106. The confluence valve V-106, the fourth compressor C-104, the fourth heat exchanger E-104, the first circulating fan P-101, and the diversion valve V-105 are connected in sequence. The diversion valve V-105 is connected to the first intermediate heat exchanger E-101, the second intermediate heat exchanger E-102, and the third intermediate heat exchanger E-103. The first intermediate heat exchanger E-101, the second intermediate heat exchanger E-102, and the third intermediate heat exchanger E-103 are connected to the confluence valve V-106. A first intermediate pressure point B-101 is set between the first compressor C-101 and the first heat exchanger E-101. A second intermediate pressure point B-102 is set between the second compressor C-102 and the second heat exchanger E-102. A third intermediate pressure point B-103 is set between the third compressor C-103 and the third heat exchanger E-103.

[0053] Air is drawn from the intermediate pressure point of the main circuit, compressed and cooled, and then returned to the main circuit. This is used to maintain the minimum safe flow of the compressor under low load and transient conditions, prevent surge, and ensure stable operation of the unit.

[0054] The air separation unit includes a regulating valve V-103, a first expander C-201, a second expander C-202, a main heat exchanger E-201, a high-pressure distillation column T-201, a low-pressure distillation column T-202, a condenser-reboiler E-202, and an argon distillation column T-203. The inlet of the regulating valve V-103 is connected to the outlet of the air compression section heat exchanger E-103, where high-pressure, ambient-temperature air is supplied. The outlet is divided into three paths: the first path connects to the first expander C-201 and the second expander C-202, where the air undergoes two stages of expansion before entering the low-pressure distillation column T-202. The second path connects to the main heat exchanger E-201, where liquid nitrogen and liquid oxygen provide cooling to the high-pressure air before it enters the expander C-202 for expansion, depressurization, and cooling before being introduced into the low-pressure distillation column T-202. The third path connects to the main heat exchanger E-201 for cryogenic cooling before being introduced into the high-pressure distillation column T-201. The high-pressure distillation column T-201 performs coarse separation of air, with a nitrogen-rich zone at the top and an oxygen-rich liquid zone (containing argon) at the bottom. The low-pressure distillation column T-201 performs fine separation of the oxygen-rich liquid from the high-pressure column, with high-purity liquid oxygen at the bottom and high-purity nitrogen at the top. The oxygen-rich liquid (containing argon) flowing from the bottom of the high-pressure distillation column T-201 and the nitrogen-rich gas at the top exchange heat with the high-purity nitrogen at the top of the low-pressure distillation column T-202 in the condenser-evaporator E-202, where the high-purity nitrogen condenses into liquid nitrogen. The nitrogen-rich gas from the high-pressure distillation column T-201, after heat exchange, is throttled by the throttling valve PV-201 and then introduced into the low-pressure distillation column T-202 for purification. The oxygen-enriched liquid (containing argon) from the bottom of the high-pressure distillation column T-201 undergoes heat exchange, and after being throttled by the throttling valve PV-202, it is connected to the argon distillation column T-203. After argon purification, the top nitrogen-enriched zone is connected to the top of the low-pressure distillation column T-202, and the bottom oxygen-enriched liquid zone is connected to the bottom of the low-pressure distillation column T-202. Purification is carried out in the low-pressure distillation column T-202 to produce high-purity liquid oxygen output.

[0055] The cryogenic air separation subsystem separates and liquefies nitrogen and oxygen in the air, storing them respectively in the liquid oxygen storage tank and the liquid nitrogen storage tank of the energy release subsystem. The heat generated by multi-stage compression is stored in the heat storage tank.

[0056] The energy release subsystem includes an energy release subsystem liquid nitrogen storage tank, an energy release subsystem liquid oxygen storage tank, an energy release subsystem pump, an energy release subsystem heat exchanger, and a turbine; the energy release subsystem liquid nitrogen storage tank, energy release subsystem pump, energy release subsystem heat exchanger, and turbine are connected in sequence.

[0057] The energy release subsystem utilizes pumps to increase the pressure of liquid nitrogen and liquid oxygen, absorbing heat from the thermal storage tank in the heat exchanger of the energy release subsystem to generate high-temperature, high-pressure gas. This gas drives an expander to generate electricity, which is used to meet the electricity needs of ASU, water electrolysis, and users when photovoltaic and wind power generation are insufficient. The nitrogen generated after power generation is used to synthesize ammonia, and the oxygen is used for pure oxygen combustion power generation, or sold to improve the system's economic efficiency.

[0058] The water electrolysis system employs technologies such as alkaline tanks, ion exchange membranes (PEM), or solid oxide electrolysis (SOEC).

[0059] The water electrolysis system includes an electrolysis unit, a compressor, a hydrogen storage tank, and an oxygen storage tank. Purified water enters the electrolysis unit, where it is electrolyzed into hydrogen and oxygen using electricity provided by a photovoltaic power generation device, wind power generation device, liquid air energy storage, ammonia gas turbine, pure oxygen coal-fired power generation, or the power grid. The hydrogen is compressed by the compressor and stored in the hydrogen storage tank, while the oxygen is stored in the oxygen storage tank. The hydrogen is used to synthesize ammonia, and the oxygen is used for pure oxygen combustion power generation or sold directly.

[0060] The ammonia synthesis system employs the HB (Haber-Bosch process) ammonia synthesis technology. The system includes an ammonia synthesis reactor, an ammonia storage tank, a liquid ammonia pump, a heat exchanger for the ammonia synthesis system, and an ammonia gas turbine. Nitrogen from the energy release subsystem generated by the turbine and hydrogen from the hydrogen storage tank in the water electrolysis system are fed into the ammonia synthesis reactor to generate liquid ammonia. This liquid ammonia can be used as a hydrogen carrier and economically stored in the liquid ammonia tank to meet other industrial needs. Alternatively, the liquid ammonia can be pressurized by the pump and heated in the ammonia synthesis system heat exchanger by absorbing heat from the ammonia gas turbine exhaust or the heat storage tank, then fed into the ammonia gas turbine to generate electricity.

[0061] The heat storage device includes a phase change material or a thermal oil tank, and its input end is connected to the air cryogenic separation subsystem (ASU), the HB ammonia synthesis system, and the water electrolysis system, respectively. The heat storage device is used to recover heat generated by the multi-stage compression of the air cryogenic separation subsystem (ASU), the heat generated by the HB ammonia synthesis system, and the heat generated by the water electrolysis system.

[0062] The pure oxygen coal-fired power generation system includes a boiler and a carbon capture device. Oxygen from the oxygen storage tank of the water electrolysis system and treated coal powder are fed into the boiler. The generated electricity is used to meet the electricity needs of the ASU (autonomous unit), water electrolysis, and users when photovoltaic and wind power generation are insufficient. The boiler's outlet is connected to the carbon capture device, and the generated carbon dioxide is recovered by the carbon capture device.

[0063] The present invention provides an integrated wind, solar, thermal and energy storage energy system with ammonia power generation and carbon capture functions. It has three operating modes: sufficient power generation, insufficient power generation and power outage. It is also designed to be flexible and can be connected to the power grid or operate independently of the power grid.

[0064] I. When the photovoltaic and wind power generation system generates sufficient electricity, as shown in Figure 3, the system supplies power to the air cryogenic separation subsystem (ASU) and the water electrolysis system. The ASU processes air through air purification, compression, and separation, separating air into liquid nitrogen and liquid oxygen, which are then stored. The water electrolysis system produces hydrogen and oxygen, which are stored in the hydrogen storage tank and oxygen storage tank, respectively. The heat generated by the ASU multi-stage compression, the ammonia synthesis system, and the water electrolysis system is stored in a thermal storage tank. Liquid nitrogen, after being pressurized by a pump in the energy release subsystem, absorbs heat from the thermal storage tank and is converted into a high-temperature, high-pressure gas. This gas, along with the hydrogen produced from water electrolysis, enters the HB ammonia synthesis reactor to produce liquid ammonia, which is then economically stored and transported to meet other industrial needs. Furthermore, the oxygen produced from water electrolysis is sold, improving the system's economic efficiency. In this mode, if the system is off-grid, the surplus electricity generated by the solar photovoltaic and wind power generation, after meeting user needs, is stored in the form of liquid nitrogen, liquid oxygen, and liquid ammonia. If the system is in grid-connected mode, the remaining electricity can be stored by the system or fed into the grid to support other industrial electricity consumption.

[0065] II. When the photovoltaic and wind power generation system generates insufficient power, as shown in Figure 4, the system only supplies power to the ASU (Air Supply Unit) and the water electrolysis system. The remaining power is supplied by liquid air storage, a pure oxygen coal-fired power generation system, an ammonia gas turbine, or the power grid. The ASU separates air into liquid nitrogen and liquid oxygen and stores them. Water electrolysis produces hydrogen and oxygen, which are stored in separate containers. The heat generated by the ASU multi-stage compression, ammonia synthesis, and water electrolysis system is stored in a thermal storage tank. After the liquid nitrogen and liquid oxygen are pressurized by a pump, they absorb heat from the thermal storage tank or the ammonia synthesis system, converting them into high-temperature, high-pressure gases to drive an expander for power generation, meeting the electricity needs of the ASU, the water electrolysis system, and users. The nitrogen, after expansion and depressurization, and the hydrogen produced by water electrolysis are used to synthesize ammonia, which then generates electricity through an ammonia gas turbine, improving the system's energy density and response speed. The oxygen, after expansion and depressurization, is used for pure oxygen combustion power generation with the oxygen produced by the water electrolysis system. The resulting carbon dioxide is collected and utilized by a carbon capture device, preventing environmental pollution. In this mode, if the system is off-grid, it generates electricity through liquid nitrogen and liquid oxygen release, ammonia gas turbines, and pure oxygen combustion, compensating for the insufficient power generation of solar photovoltaic and wind power, and meeting the system's operation and user needs. If the system is grid-connected, in addition to the system's energy release, it can also be powered by the grid, enhancing the reliability of the system's power supply.

[0066] III. When the photovoltaic and wind power generation system experiences a power outage, as shown in Figure 5, the ASU (Air Supply Unit) ceases operation. The water electrolysis system is powered by liquid air energy storage, a pure oxygen coal-fired power generation system, an ammonia gas turbine, or the power grid. The heat generated by the water electrolysis and ammonia synthesis systems is stored in a thermal storage tank. Liquid nitrogen and liquid oxygen in the storage tank are pressurized by pumps, absorbing heat from the thermal storage tank or the ammonia synthesis system, and converted into high-temperature, high-pressure gas. This gas drives an expander to generate electricity, meeting the power needs of the water electrolysis system and users. After nitrogen expands and depressurizes, it reacts with hydrogen produced from water electrolysis to enter the ammonia synthesis reactor, producing liquid ammonia, which generates electricity through an ammonia gas turbine, improving the system's energy density and response speed. After oxygen expands and depressurizes, it reacts with oxygen produced from the water electrolysis system for pure oxygen combustion power generation. The resulting carbon dioxide is collected and utilized by a carbon capture device, preventing environmental pollution. In this mode, if the system is off-grid, it only releases energy through liquid nitrogen and liquid oxygen, and generates electricity through the ammonia gas turbine and pure oxygen combustion to meet system operation and user needs. If the system is grid-connected, in addition to system energy release, it can also be powered by the grid, enhancing the reliability of the power supply.

[0067] This invention provides an integrated wind-solar-thermal-storage energy system with ammonia-electricity production and carbon capture functions. It combines photovoltaic, wind power generation, liquefied gas storage, water electrolysis for hydrogen production, ammonia synthesis, and carbon capture technologies, creating a clean energy system that integrates ammonia, electricity production, and carbon capture. This system utilizes liquid air storage for long-term electricity storage, enabling continuous operation during photovoltaic and wind power generation and power outages. It can be connected to the grid or operate independently, solving the intermittency problem in renewable energy utilization and improving equipment utilization and operational efficiency. Furthermore, the hydrogen produced by water electrolysis and the nitrogen generated during the cryogenic separation of air in the liquefied gas storage process are used to generate liquid ammonia using ammonia synthesis technology, reducing hydrogen storage costs and improving the system's economics. The generated ammonia can be used to output electricity through a gas turbine, while the oxygen generated during cryogenic air separation is used for pure oxygen-fired coal-fired boiler power generation, effectively improving the system's energy density and response speed. Finally, carbon capture is used to recover carbon dioxide generated from pure oxygen-fired coal combustion to reduce emissions. The coordinated operation and complementary advantages of each part of the system effectively improve the utilization efficiency of renewable energy and ensure efficient energy storage and conversion.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions for some or all of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated wind-solar-thermal-storage energy system with ammonia power generation and carbon capture functions, characterized in that, include: The system comprises a photovoltaic wind power generation system, a liquid air energy storage system, a water electrolysis system, a synthetic ammonia system, a thermal energy storage device, and a pure oxygen coal-fired power generation system. The liquid air energy storage system includes a cryogenic air separation subsystem and an energy release subsystem. The cryogenic air separation subsystem includes an air purification unit, an air compression unit, and an air separation unit. The cryogenic air separation subsystem separates and liquefies nitrogen and oxygen from the air, storing them respectively in a liquid oxygen storage tank and a liquid nitrogen storage tank within the energy release subsystem. The heat generated by multi-stage compression is stored in the thermal energy storage device. The energy release subsystem includes a liquid nitrogen storage tank, a liquid oxygen storage tank, a pump, a heat exchanger, and a turbine. The liquid nitrogen and liquid oxygen storage tanks, the pump, the heat exchanger, and the turbine are connected sequentially.

2. The integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions as described in claim 1, characterized in that, The photovoltaic wind power generation system includes multiple sets of photovoltaic power generation devices and / or multiple sets of wind power generation devices.

3. The integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions as described in claim 1, characterized in that, The air purification unit includes a first molecular sieve adsorption tower T-301A and a second molecular sieve adsorption tower T-301B; the input ends of the first molecular sieve adsorption tower T-301A and the second molecular sieve adsorption tower T-301B are connected to the bottom switching valve group V-101, and the output ends are connected to the top switching valve group V-102; the bottom switching valve group V-101 is connected to the atmospheric environment.

4. The integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions according to claim 3, characterized in that, The air compression unit includes a main circuit and a loop. The main circuit includes a first compressor C-101, a second compressor C-102, a third compressor C-103, a first intermediate heat exchanger E-101, a second intermediate heat exchanger E-102, and a third intermediate heat exchanger E-103. The first compressor C-101, the first intermediate heat exchanger E-101, the second main circuit compressor C-102, the second intermediate heat exchanger E-102, the third compressor C-103, and the third intermediate heat exchanger E-103 are connected in sequence. The first compressor C-101 is connected to the tower top switching valve group V-102 of the air purification unit, and the outlet of the third intermediate heat exchanger E-103 is connected to the diversion valve V-103 of the air separation unit. The loop includes a fourth compressor C-104, a fourth heat exchanger E-104, a first circulating fan P-101, and a diversion valve V-105. A confluence valve V-106 is provided. The confluence valve V-106, the fourth compressor C-104, the fourth heat exchanger E-104, the first circulating fan P-101, and the diverter valve V-105 are connected in sequence. The diverter valve V-105 is connected to the first intermediate heat exchanger E-101, the second intermediate heat exchanger E-102, and the third intermediate heat exchanger E-103. The first intermediate heat exchanger E-101, the second intermediate heat exchanger E-102, and the third intermediate heat exchanger E-103 are connected to the confluence valve V-106. A first intermediate pressure point B-101 is provided between the first compressor C-101 and the first heat exchanger E-101. A second intermediate pressure point B-102 is provided between the second compressor C-102 and the second heat exchanger E-102. A third intermediate pressure point B-103 is provided between the third compressor C-103 and the third heat exchanger E-103.

5. The integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions according to claim 4, characterized in that, The air separation unit includes a regulating valve V-103, a first expander C-201, a second expander C-202, a main heat exchanger E-201, a high-pressure distillation column T-201, a low-pressure distillation column T-202, a condenser-reboiler E-202, and an argon distillation column T-203. The inlet of the regulating valve V-103 is connected to the outlet of the air compression section heat exchanger E-103, where high-pressure and ambient temperature air is supplied. The outlet is divided into three paths: the first path connects to the first expander C-201 and the second expander C-202 for two-stage expansion before entering the low-pressure distillation column T-202; the second path connects to the main heat exchanger E-201, where liquid nitrogen and liquid oxygen provide cooling to the high-pressure air before it enters the expander C-202 for expansion, depressurization, and cooling before being introduced into the low-pressure distillation column T-202; and the third path connects to the main heat exchanger E-201 for cryogenic cooling before being introduced into the high-pressure distillation column T-201.

6. The integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions according to claim 1, characterized in that, The water electrolysis system includes an water electrolysis unit, a compressor, a hydrogen storage tank for the water electrolysis system, and an oxygen storage tank for the water electrolysis system.

7. The integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions as described in claim 1, characterized in that, The ammonia synthesis system adopts the HB ammonia synthesis process, and the ammonia synthesis system includes an ammonia synthesis reactor, an ammonia storage tank, a liquid ammonia pump, an ammonia synthesis system heat exchanger, and an ammonia gas turbine.

8. The integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions according to claim 1, characterized in that, The heat storage device includes a phase change material or a thermal oil tank, and the input end of the heat storage device is connected to the air cryogenic separation subsystem, the HB ammonia synthesis system, and the water electrolysis system, respectively.

9. The integrated wind, solar, thermal, and energy storage system with ammonia power generation and carbon capture functions according to claim 1, characterized in that, The pure oxygen coal-fired power generation system includes a boiler and a carbon capture device; oxygen from the oxygen storage tank of the electrolysis water system and treated coal powder are fed into the boiler; the boiler's outlet is connected to the carbon capture device, and the generated carbon dioxide is recovered by the carbon capture device.

10. The integrated wind-solar-thermal-storage energy system with ammonia power generation and carbon capture functions according to any one of claims 1-9, characterized in that, The integrated wind-solar-thermal-storage energy system with ammonia power generation and carbon capture functions has three operating modes: sufficient power generation, insufficient power generation, and power outage. When the photovoltaic-wind power generation system generates sufficient power, it supplies power to the air cryogenic separation subsystem and the water electrolysis system. The cryogenic air separation subsystem separates air into liquid nitrogen and liquid oxygen through air purification, air compression, and air separation, and stores them; the water electrolysis system produces hydrogen and oxygen, which are stored in the hydrogen storage tank and oxygen storage tank of the water electrolysis system, respectively. The heat generated by the multi-stage compression of the air cryogenic separation subsystem, the ammonia synthesis system, and the water electrolysis system is stored in a thermal storage tank. After the liquid nitrogen is pressurized by the pump of the energy release subsystem, it absorbs the heat in the thermal storage tank and is converted into a high-temperature and high-pressure gas. This gas, along with the hydrogen produced by water electrolysis, enters the HB ammonia synthesis reactor to produce liquid ammonia. When the photovoltaic and wind power generation system generates insufficient power, it only supplies power to the air cryogenic separation subsystem and the water electrolysis system. The insufficient power is supplied by liquid air energy storage, pure oxygen coal-fired power generation system, ammonia gas turbine, or the power grid. The cryogenic air separation subsystem separates air into liquid nitrogen and liquid oxygen, which are then stored. Water electrolysis produces and stores hydrogen and oxygen. Heat generated by the multi-stage compression, ammonia synthesis, and water electrolysis systems within the cryogenic air separation subsystem is stored in a thermal storage tank. Liquid nitrogen and liquid oxygen, after being pressurized by a pump, absorb heat from the thermal storage tank or ammonia synthesis system, transforming into high-temperature, high-pressure gases to drive an expander for power generation, meeting the electricity needs of the cryogenic air separation subsystem, the water electrolysis system, and users. The nitrogen, after expansion and depressurization, and the hydrogen produced from water electrolysis are used to synthesize ammonia, which then generates electricity through an ammonia gas turbine. Oxygen, after expansion and depressurization, is combined with oxygen produced by the water electrolysis system for pure oxygen combustion power generation; the resulting carbon dioxide is collected and utilized by a carbon capture device. When photovoltaic... When the wind power generation system loses power, the cryogenic air separation subsystem stops working. The water electrolysis system is powered by liquid air energy storage, a pure oxygen coal-fired power generation system, an ammonia gas turbine, or the power grid. The heat generated by the water electrolysis and ammonia synthesis systems is stored in a thermal storage tank. The liquid nitrogen and liquid oxygen in the storage tank are pressurized by a pump and then absorb the heat generated by the thermal storage tank or the ammonia synthesis system, converting them into high-temperature and high-pressure gases to drive an expander to generate electricity, meeting the electricity needs of the water electrolysis system and users. After the nitrogen expands and depressurizes, it enters the ammonia synthesis reactor with the hydrogen generated by the water electrolysis system to produce liquid ammonia, which generates electricity through an ammonia gas turbine. After the oxygen expands and depressurizes, it undergoes pure oxygen combustion with the oxygen generated by the water electrolysis system to generate electricity. The carbon dioxide produced is collected and utilized by a carbon capture device.

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