Zero carbon emission system and method for deep peak regulation by coal gasification coupled with power station boiler

Abstract

Embodiments of the present invention provide a zero carbon emission system and method for deep peak regulation by coal gasification coupled with a power station boiler. The zero carbon emission system comprises a coal gasifier, a power station boiler, a carbon dioxide storage tank, and a gasification agent mixer. A first gasification gas nozzle of the coal gasifier is communicated with a main burning zone of a boiler body of the power station boiler, a second gasification gas nozzle of the coal gasifier is communicated with a reburning zone of the boiler body of the power station boiler, and an outlet of the boiler body of the power station boiler is communicated with the carbon dioxide storage tank, so as to collect carbon dioxide. The carbon dioxide storage tank is further communicated with the gasification agent mixer, and the gasification agent mixer is communicated with the coal gasifier. The gasification agent mixer is used for mixing extracted steam from a steam turbine and part of carbon dioxide in the carbon dioxide storage tank, so as to generate a gasification agent for supply to the coal gasifier to realize deep peak regulation. According to the zero carbon emission system in the embodiments of the present invention, the coal gasifier is deeply coupled with the power station boiler, so that low-load stable combustion under deep peak regulation of the power station boiler and zero carbon emissions of the entire system are realized.

Description

Zero-carbon emission system and method for deep peak regulation of coal gasification-coupled power plant boilers Technical Field

[0001] The embodiments of the present invention belong to the technical field of deep peak regulation of power plant boilers, and specifically relate to a zero-carbon emission system and method for deep peak regulation of coal gasification coupled with power plant boilers. Background Art

[0002] In recent years, my country's installed capacity of wind and photovoltaic power generation has continued to rise, but this has been accompanied by a surge in curtailed solar and wind power. While the share of thermal power generation capacity has been declining in recent years, its share of electricity generation still exceeds 60%, demonstrating that thermal power still plays a crucial role in my country's energy mix. Therefore, as my country's energy landscape continues to evolve, it requires deep peak load regulation for thermal power units.

[0003] In areas with large installed capacity of renewable energy generation but significant wind and solar curtailment, thermal power generators still need to operate at high loads during peak electricity demand periods. This requires thermal power generators to implement deep peak-shaving and mitigate the impact of renewable energy generation on the grid during periods of low electricity demand. However, low-rank coal reserves currently account for over 45% of my country's proven coal reserves. Due to its low degree of coalification, low-rank coal is difficult to burn directly in power plant boilers, especially for low-load stable combustion during deep peak-shaving. Furthermore, due to the high carbon emissions of thermal power generators, they also pose a significant threat to the environment.

[0004] Summary of the Invention

[0005] The embodiments of the present invention aim to solve at least one of the technical problems existing in the prior art and provide a zero-carbon emission system and method for deep peak regulation of coal gasification coupled power plant boilers.

[0006] In one aspect, an embodiment of the present invention provides a zero-carbon emission system for deep peak shaving of coal gasification coupled with a power plant boiler, the zero-carbon emission system comprising a coal gasifier, a power plant boiler, a carbon dioxide storage tank, and a gasifying agent mixer;

[0007] The first gasification gas nozzle of the coal gasifier is connected to the main combustion zone of the boiler body of the power station boiler, the second gasification gas nozzle of the coal gasifier is connected to the reburning zone of the boiler body of the power station boiler, and the boiler body outlet of the power station boiler is connected to the carbon dioxide storage tank to collect carbon dioxide;

[0008] The carbon dioxide storage tank is also connected to the gasifying agent mixer, and the gasifying agent mixer is connected to the coal gasifier; wherein,

[0009] The gasifying agent mixer is used to mix the steam extracted from the steam turbine and part of the carbon dioxide in the carbon dioxide storage tank to generate a gasifying agent to be supplied to the coal gasifier to achieve deep peak regulation.

[0010] Optionally, the zero-carbon emission system further includes a coke storage device and a coal mill;

[0011] The coke storage device is connected to the coke outlet of the coal gasifier, and the coke storage device is also connected to the inlet of the coal mill, and the outlet of the coal mill is connected to the main combustion zone of the boiler body of the power station boiler; wherein,

[0012] The coal mill is used to grind coke into fine coke and transport the fine coke to the main combustion zone of the boiler body of the power station boiler.

[0013] Optionally, the coal mill outlet includes a first fine coke nozzle and a second fine coke nozzle;

[0014] The first and second fine coke nozzles are connected to the main combustion zone of the boiler body of the power station boiler, and the first and second fine coke nozzles are located between the first and second gasification gas nozzles.

[0015] Optionally, the boiler body of the power station boiler is sequentially arranged with the main combustion zone, the reburning zone and the burnout zone from bottom to top.

[0016] Optionally, the zero-carbon emission system further includes an electrolytic water tank, an oxygen storage tank, a gas mixer and a first blower;

[0017] The electrolytic water tank generates oxygen through new energy generation, and the oxygen enters the oxygen storage tank, which is connected to the gas mixer, and the gas mixer is also connected to the carbon dioxide storage tank; wherein,

[0018] The gas mixer is used to mix the oxygen in the oxygen storage tank and part of the carbon dioxide in the carbon dioxide storage tank to generate primary air, secondary air and burnout air;

[0019] The first fan is used to transport the primary air, secondary air and overburned air into the boiler body of the power station boiler.

[0020] Optionally, the zero-carbon emission system further includes a first heat exchanger, a second heat exchanger, and an air preheater disposed in the boiler body;

[0021] The first heat exchanger is connected to the gas mixer, and is used to transport the primary air to the first fan, and then transport the primary air to the air preheater through the first fan;

[0022] The second heat exchanger is connected to the first heat exchanger, and is used to transport the secondary air and the overburned air to the first fan, and then transport the secondary air and the overburned air to the air preheater through the first fan.

[0023] Optionally, the heat required for heat exchange in the first heat exchanger and the second heat exchanger is the dry quenching waste heat brought out by the inert gas in the coke storage device.

[0024] Optionally, the zero-carbon emission system further comprises an air carbon dioxide capture device;

[0025] The air-to-carbon dioxide capture device captures carbon dioxide by generating electricity using new energy, and transports the carbon dioxide to the carbon dioxide storage tank.

[0026] Optionally, the zero-carbon emission system further includes a flue gas dust collector and a second fan;

[0027] The flue gas dust collector and the second fan are sequentially arranged between the boiler body outlet of the power station boiler and the carbon dioxide storage tank; and the carbon dioxide discharged from the boiler body outlet of the power station boiler enters the carbon dioxide storage tank via the flue gas dust collector and the second fan in sequence.

[0028] In another aspect, an embodiment of the present invention provides a zero-carbon emission method for deep peak shaving of coal gasification coupled to a power plant boiler, using the zero-carbon emission system described above. The method includes:

[0029] When there is excess electricity generation from renewable energy, it will power the water electrolysis tank and the air capture carbon dioxide system respectively, and the generated hydrogen, oxygen and carbon dioxide will be stored in hydrogen storage tanks, oxygen storage tanks and carbon dioxide storage tanks respectively;

[0030] A portion of the carbon dioxide in the carbon dioxide storage tank and a portion of the steam extracted from the turbine are mixed in a gasifying agent mixer to serve as a gasifying agent;

[0031] Part of the hydrogen in the hydrogen storage tank is used to prepare ammonia, and the other part is prepared as liquid hydrogen and passed into the liquid hydrogen storage tank for storage;

[0032] The oxygen in the oxygen storage tank and the carbon dioxide in the carbon dioxide storage tank are introduced into a gas mixer for thorough mixing to obtain an oxygen / carbon dioxide mixed gas as primary air, secondary air and burnout air;

[0033] Under the action of the gasifying agent and coal, the coal gasifier produces gasification gas, tar, and coke; wherein the gasification gas is respectively fed into the main combustion zone and the reburning zone of the boiler body through the first gasification gas nozzle and the second gasification gas nozzle as combustion-supporting fuel and reburning fuel; the coke is first collected in the coke storage device, the large coke particles are collected as chemical products, and the small coke particles are crushed into fine coke in the coal mill and then fed into the main combustion zone of the boiler body for combustion;

[0034] The primary air is preheated in the first heat exchanger, and the secondary air and the burnt air are preheated in stages in the first heat exchanger and the second heat exchanger; the heat required for preheating is the residual heat of the dry quenching of the coke carried out by the inert gas in the coke storage device;

[0035] The tail flue gas passes through a flue gas dust collector and a fan and is then sent into the carbon dioxide storage tank for storage.

[0036] The zero-carbon emission system and method for deep peak regulation of coal gasification coupled with power plant boilers in the embodiments of the present invention can achieve low-load stable combustion, chemical polygeneration, and zero-carbon emission of the entire industrial system under deep peak regulation of power plant boilers through the deep coupling of the provided coal gasifier, power plant boiler, carbon dioxide storage tank, and gasifying agent mixer. In addition, the interaction of energy and matter in the coal gasifier and power plant boiler also realizes high efficiency and low NOx of the power plant boiler. x Combustion has promoted the development of low-grade coal applications in my country, and ultimately achieved an increase in the production efficiency of industrial systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG1 is an overall schematic diagram of a zero-carbon emission system for coal gasification coupled with deep peak regulation of power plant boilers according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0039] my country's coal gasification technology has made significant progress in recent years, reaching internationally advanced levels in both process and product quality. Low-rank coal gasification produces gasification gas, tar, and coke, all of which can be collected as chemical products. Gasification gas is also a high-quality fuel gas composed of combustible gases such as CO, CH₄, and H₂. This demonstrates that combining coal gasification technology with coal-fired power plant boilers is advantageous for achieving deep peak load regulation in power plant boilers.

[0040] Since the Paris Agreement, countries around the world have paid particular attention to climate change caused by carbon emissions. my country, as a major energy producer and consumer, has proposed a dual carbon strategy: achieving carbon peak by 2030 and carbon neutrality by 2060. Thermal power generation units have high carbon emissions. If O2 / CO2 combustion is performed in power plant boilers, flue gas containing over 95% CO2 will be captured, facilitating carbon sequestration and reducing carbon emissions from thermal power generation. Furthermore, significant progress has been made in air capture of carbon dioxide (DAC) technology, which can also be used to absorb excess wind and photovoltaic power generation, reducing the impact on the power grid.

[0041] In view of this, the inventor proposed a zero-carbon emission system and method for coal gasification coupled with deep peak regulation of power plant boilers, which can realize the combination of coal gasification technology and deep peak regulation of coal-fired power plant boilers. It not only stabilizes the power supply load of the power grid, but also optimizes my country's energy structure. The entire industrial system has zero carbon emissions, which will help my country achieve its dual carbon strategy.

[0042] As shown in Figure 1, a zero-carbon emission system 100 for deep peak shaving of coal gasification coupled with a utility boiler is shown. The zero-carbon emission system 100 includes a coal gasifier 110, a utility boiler 120, a carbon dioxide storage tank 130, and a gasifying agent mixer 140. A first gasification gas nozzle 111 of the coal gasifier 110 is connected to the main combustion zone of the boiler body of the utility boiler 120. A second gasification gas nozzle 112 of the coal gasifier 110 is connected to the reburning zone of the boiler body of the utility boiler 120. The boiler body outlet of the utility boiler 120 is connected to the carbon dioxide storage tank 130 to collect carbon dioxide.

[0043] The carbon dioxide storage tank 130 is also connected to the gasifying agent mixer 140, which is in communication with the coal gasifier 110. The gasifying agent mixer 140 is used to mix turbine extraction steam and a portion of the carbon dioxide in the carbon dioxide storage tank 130 to produce a gasifying agent that is supplied to the coal gasifier 110 for deep peak shaving.

[0044] Specifically, as shown in FIG1 , coal enters the coal gasifier 110 to produce three chemical products: gasification gas, tar, and coke. The gasification gas can be stored in the gasification gas storage tank 200. The gasification gas in the gasification gas storage tank 200 can be used for chemical purposes on the one hand, and can be sent to the main combustion zone and reburning zone of the boiler body of the power station boiler 120 through the first gasification gas nozzle 111 and the second gasification gas nozzle 112, respectively. By using coal gasification technology to treat low-quality coal with low volatile content, the generated gasification gas can be used for combustion support and reburning, which can achieve low-load stable combustion and low NO in the power station boiler 120. xThe boiler outlet of the power station boiler 120 is connected to the carbon dioxide storage tank 130, which is used to collect the carbon dioxide discharged from the boiler outlet to achieve zero carbon emissions in the system.

[0045] A portion of the carbon dioxide gas in the carbon dioxide storage tank 130 is transferred to the gasifying agent mixer 140, along with the turbine extraction steam. The gasifying agent mixer 140 mixes the carbon dioxide within it with the turbine extraction steam, and the resulting mixed gas is supplied as a gasifying agent to the coal gasifier 110. The gasified gas generated by the low-quality coal in the coal gasifier 110, fueled by the gasifying agent, supports the combustion of the power plant boiler 120, thereby achieving deep peak load regulation for the power plant boiler 120.

[0046] The zero-carbon emission system for deep peak regulation of coal gasification coupled with power plant boilers in the embodiment of the present invention can achieve low-load stable combustion, chemical polygeneration, and zero-carbon emission of the entire industrial system under deep peak regulation of power plant boilers through the provided coal gasification furnace, power plant boiler, carbon dioxide storage tank, and gasification agent mixer. In addition, the interaction of energy and matter in the coal gasification furnace and power plant boiler also realizes the high efficiency and low NO x Combustion has promoted the development of low-grade coal applications in my country, and ultimately achieved an increase in the production efficiency of industrial systems.

[0047] For example, as shown in FIG1 , the zero-carbon emission system 100 further includes a coke storage device 150 and a coal mill 151. The coke storage device 150 is connected to the coke outlet of the coal gasifier 110. The coke storage device 150 is also connected to the inlet of the coal mill 151. The outlet of the coal mill 151 is connected to the main combustion zone of the boiler body of the utility boiler 120. The coal mill 151 is used to grind the coke into fine coke and transport the fine coke to the main combustion zone of the boiler body of the utility boiler 120.

[0048] Specifically, as shown in Figure 1, the tar produced by coal gasifier 110 can be used for chemical production. The coke produced by coal gasifier 110 is stored in coke storage device 150. Large coke particles can be collected as chemical products, while small coke particles are transported to coal mill 151 for grinding into fine coke. The ground fine coke is then transported to the main combustion zone of the boiler body of the power station boiler 120. Using the gasification gas with a high combustible gas component produced by coal gasifier 110 to assist in the combustion of fine coke can further achieve deep peak load regulation of the power station boiler.

[0049] Furthermore, the outlet of the coal mill 151 includes a first coke powder nozzle 152 and a second coke powder nozzle 153. The first coke powder nozzle 152 and the second coke powder nozzle 153 are connected to the main combustion zone of the boiler body of the power plant boiler 120, and the first coke powder nozzle 152 and the second coke powder nozzle 153 are located between the first gasification gas nozzle 111 and the second gasification gas nozzle 112.

[0050] Specifically, as shown in Figure 1, within the main combustion zone of the boiler body of the power plant boiler 120, the first gasification gas nozzle 111 is arranged below the first fine coke nozzle 152 and the second fine coke nozzle 153. The heat generated by the gasification gas nozzle 111 assists in the combustion of fine coke, effectively achieving low-load stable combustion under deep peak regulation of the power plant boiler 120. Furthermore, the gasification gas is simultaneously delivered as reburn fuel through the second gasification gas nozzle 112 into the reburn zone of the boiler body of the power plant boiler 120, further reducing NOx during the combustion process. x As a specific example, as shown in FIG1 , the boiler body of the power station boiler 120 is sequentially arranged with the main combustion zone, the reburning zone and the burnout zone from bottom to top.

[0051] For example, as shown in FIG1 , the zero-carbon emission system 100 further includes an electrolytic water tank 160, an oxygen storage tank 161, a gas mixer 162, and a first blower 163. The electrolytic water tank 160 generates oxygen through renewable energy generation, and the oxygen enters the oxygen storage tank 161. The oxygen storage tank 161 is connected to the gas mixer 162, and the gas mixer 162 is also connected to the carbon dioxide storage tank 130. The gas mixer 162 is used to mix the oxygen in the oxygen storage tank 161 and part of the carbon dioxide in the carbon dioxide storage tank 130 to generate primary air, secondary air, and overburned air. The first blower 163 is used to transport the primary air, secondary air, and overburned air to the boiler body of the power station boiler 120.

[0052] Specifically, as shown in FIG1 , the electrolytic water tank 160 utilizes the electricity generated by photovoltaic, wind and other new energy sources that cannot be absorbed by the power grid to electrolyze water to produce hydrogen and oxygen. Hydrogen can be stored in a hydrogen storage tank 300. A portion of the hydrogen in the hydrogen storage tank 300 can be used to prepare ammonia, and the other portion can be prepared as liquid hydrogen and passed into a liquid hydrogen storage tank 400 for storage for the next step of transportation and use in the chemical industry. Oxygen can be stored in an oxygen storage tank 161. The oxygen in the oxygen storage tank 161 and a portion of the carbon dioxide in the carbon dioxide storage tank 130 are passed into a gas mixer 162 to mix into a mixed gas to generate primary air, secondary air and burnout air. The generated primary air, secondary air and burnout air are transported to the boiler body of the power station boiler 120 through the first blower 163 for combustion, which can further reduce NO in the combustion. x Amount generated.

[0053] The zero-carbon emission system for deep peak regulation of power plant boilers coupled with coal gasification in the embodiment of the present invention realizes combustion of oxygen / carbon dioxide mixed gas in power plant boilers by electrolyzing water to reduce NOx in power plant boilers compared with air combustion. x The amount of carbon generated is also conducive to carbon capture and storage.

[0054] For example, as shown in FIG1 , the zero-carbon emission system 100 further includes a first heat exchanger 170, a second heat exchanger 171, and an air preheater 172 disposed within the boiler body. The first heat exchanger 170 is connected to the gas mixer 162 and is used to deliver the primary air to the first fan 163, which then delivers the primary air to the air preheater 172 via the first fan 163. The second heat exchanger 171 is connected to the first heat exchanger 170 and is used to deliver the secondary air and overburned air to the first fan 163, which then delivers the secondary air and overburned air to the air preheater 172 via the first fan 163.

[0055] Specifically, as shown in Figure 1, the primary air, secondary air, and overburned air generated by the gas mixer 162 are preheated in stages in the first heat exchanger 170 and the second heat exchanger 171. The primary air is heated by the first heat exchanger 170 and then delivered to the air preheater 172 via the first fan 163. The air preheater 172 preheats the primary air before it is fed into the power plant boiler 120 for combustion. The secondary air and overburned air are heated by the second heat exchanger 171 and then delivered to the air preheater 172 via the first fan 163. The air preheater 172 preheats the secondary air and overburned air before they are fed into the power plant boiler 120 for combustion. It should be noted that the overburned air is fed into the burnout zone of the boiler body of the power plant boiler for combustion.

[0056] Furthermore, the heat required for heat exchange in the first heat exchanger 170 and the second heat exchanger 171 is the residual heat from dry quenching of coke carried out by the inert gas in the coke storage device 150. By using the residual heat from dry quenching of coke carried out by the inert gas to preheat the primary air, secondary air and burnout air in a stepwise manner, the combustion efficiency of the power plant boiler can be improved. In addition, the gasification gas is used as a reburning fuel to reduce NO in the combustion process. x generation, ultimately achieving high efficiency and low NOx in power station boilers x combustion.

[0057] 1 , the zero-carbon emission system 100 further includes an air-to-carbon dioxide capture device 180 . The air-to-carbon dioxide capture device 180 captures carbon dioxide through renewable energy generation and transports the carbon dioxide to the carbon dioxide storage tank 130 .

[0058] Specifically, as shown in Figure 1, CO2 is captured by an air-to-carbon capture system 180 using renewable energy sources such as photovoltaic and wind power that cannot be absorbed by the power grid. The resulting CO2 is then transported to a CO2 storage tank 130 for storage. The CO2 in the CO2 storage tank 130 is then mixed with oxygen in a gas mixer 162 to form an oxygen / CO2 mixed gas, which is then fed into the power plant boiler 120 for combustion. Both the air-to-carbon capture system and the combustion of the oxygen / CO2 mixed gas effectively capture and store carbon, ultimately enabling the entire system to achieve zero carbon emissions.

[0059] Exemplarily, the zero-carbon emission system 100 further includes a flue gas dust collector 190 and a second fan 191. The flue gas dust collector 190 and the second fan 191 are sequentially disposed between the boiler outlet of the power plant boiler 120 and the carbon dioxide storage tank 130. Carbon dioxide exhausted from the boiler outlet of the power plant boiler 120 enters the carbon dioxide storage tank 130 via the flue gas dust collector 190 and the second fan 191.

[0060] Specifically, as shown in Figure 1, the tail flue gas discharged from the boiler main body outlet of the power plant boiler 120 passes through a flue gas dust collector 190 and a second blower 191 before being sent to a carbon dioxide storage tank 130 for storage. The boiler tail flue collects flue gas containing greater than 95% carbon dioxide, enabling carbon capture and sequestration. After dust removal and other processes, the flue gas is stored in the carbon dioxide storage tank 130 along with the carbon dioxide captured by the air capture device 180.

[0061] The zero-carbon emission system for deep peak regulation of power plant boilers coupled with coal gasification in the embodiment of the present invention utilizes the increased power generation capacity of new energy sources to electrolyze water and capture carbon dioxide from air, and then performs oxygen / carbon dioxide combustion in the power plant boiler. In addition, the coal gasification technology is used to treat low-quality coal with low volatile content, and the generated gasification gas is used for combustion support and reburning, thereby achieving low-load stable combustion and low NO in power plant boilers. x This system not only stabilizes the power supply load of the power grid, but also optimizes my country's energy structure and contributes to the realization of my country's dual carbon strategy.

[0062] Renewable energy generation that cannot be absorbed by the power grid is used to produce carbon dioxide, hydrogen, and oxygen in water electrolyzers and air-to-gas CO2 capture units. Hydrogen can be used to produce chemical products such as liquid hydrogen and ammonia, while oxygen and CO2 are mixed and used as primary air, secondary air, and overburned air for oxygen / CO2 combustion in power plant boilers. Coal gasification technology is used to convert low-quality coal into chemical products such as tar, gasification gas, and coke. The gasification gas can be collected as a chemical product or burned as fuel in power plant boilers, achieving stable low-load combustion. Tar and large coke particles are collected as chemical products, while small coke particles are crushed and burned in power plant boilers. The residual heat from dry quenching of coke removed by inert gas is used to preheat the primary, secondary, and overburned air in a cascade, improving the combustion efficiency of power plant boilers. Flue gas with a CO2 content exceeding 95% is collected in the boiler tail flue. After dust removal and other processes, the flue gas is subjected to carbon capture and storage.

[0063] The zero-carbon emission system for deep peak regulation of coal gasification coupled power plant boilers of the embodiment of the present invention not only realizes deep peak regulation of power plant boilers through gasification gas combustion, but also realizes zero carbon emission through oxygen / carbon dioxide combustion, carbon capture and carbon sequestration technology. By deeply coupling the coal gasifier, power plant boiler, water electrolysis device and air carbon dioxide capture device, the goals of low-load stable combustion under deep peak regulation of power plant boilers and zero carbon emission of the entire system are achieved at the same time. In addition, the interaction of energy and matter in the coal gasifier and power plant boiler also realizes high efficiency and low NO of power plant boilers. x Combustion has driven the development of low-rank coal applications in my country, ultimately improving industrial system production efficiency. The entire system can collect chemical products such as gasification gas, tar, coke, ammonia, hydrogen, carbon dioxide, electricity, and steam, achieving chemical polygeneration by coupling multiple industrial systems.

[0064] In another aspect, embodiments of the present invention provide a zero-carbon emission method for deep peak shaving of coal gasification-coupled power plant boilers. The method utilizes the aforementioned zero-carbon emission system 100. The method includes the following steps: When excess renewable energy generation occurs, power is supplied to a water electrolysis tank 160 and an air-to-carbon dioxide capture device 180. The generated hydrogen, oxygen, and carbon dioxide are stored in a hydrogen storage tank 300, an oxygen storage tank 161, and a carbon dioxide storage tank 130, respectively. A portion of the carbon dioxide in the carbon dioxide storage tank 130 and a portion of the turbine extraction steam are mixed in a gasifying agent mixer 140 to serve as a gasifying agent.

[0065] A portion of the hydrogen in the hydrogen storage tank 300 is used to produce ammonia, while the remaining portion is converted into liquid hydrogen and then passed into the liquid hydrogen storage tank 400 for storage. The oxygen in the oxygen storage tank 161 and the carbon dioxide in the carbon dioxide storage tank 130 are passed into the gas mixer 162 for thorough mixing, producing an oxygen / carbon dioxide mixed gas as the primary air, secondary air, and burnout air.

[0066] The gasification agent reacts with coal to produce gasification gas, tar, and coke in the coal gasifier 110. The gasification gas is fed into the main combustion zone and reburning zone of the boiler body through the first gasification gas nozzle 111 and the second gasification gas nozzle 112, respectively, as combustion-supporting fuel and reburning fuel. The coke is first collected in the coke storage device 150. Large coke particles are collected as chemical products, while small coke particles are crushed into fine coke in the pulverizer 151 and then fed into the main combustion zone of the boiler body for combustion. The primary air is preheated in the first heat exchanger 170, while the secondary air and overburned air are preheated in stages in the first and second heat exchangers 170, 171. The heat required for preheating is the residual heat from the dry quenching of the coke removed by the inert gas in the coke storage device 150. The tail flue gas passes through the flue gas dust collector 190 and the second fan 191 before being fed into the carbon dioxide storage tank 130 for storage.

[0067] The zero-carbon emission method for deep peak regulation of coal gasification coupled with power plant boilers in the embodiment of the present invention achieves the goals of low-load stable combustion, chemical polygeneration, and zero-carbon emission of the entire system under deep peak regulation of power plant boilers by deeply coupling the coal gasifier, power plant boiler, water electrolysis device, and air carbon dioxide capture device. In addition, the interaction of energy and matter in the coal gasifier and power plant boiler also achieves high efficiency and low NO x Combustion has promoted the development of low-grade coal applications in my country and ultimately achieved an improvement in the production efficiency of industrial systems.

[0068] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A zero-carbon emission system for coal gasification coupled with deep peak regulation of power plant boilers, characterized by: The zero-carbon emission system includes a coal gasifier, a power plant boiler, a carbon dioxide storage tank and a gasifying agent mixer; The first gasification gas nozzle of the coal gasifier is connected to the main combustion zone of the boiler body of the power station boiler, the second gasification gas nozzle of the coal gasifier is connected to the reburning zone of the boiler body of the power station boiler, and the boiler body outlet of the power station boiler is connected to the carbon dioxide storage tank to collect carbon dioxide; The carbon dioxide storage tank is also connected to the gasifying agent mixer, and the gasifying agent mixer is connected to the coal gasifier; wherein, The gasifying agent mixer is used to mix the steam extracted from the steam turbine and part of the carbon dioxide in the carbon dioxide storage tank to generate a gasifying agent to be supplied to the coal gasifier to achieve deep peak regulation.

2. The zero carbon emission system according to claim 1, characterized in that: The zero carbon emission system also includes a coke storage device and a coal mill; The coke storage device is connected to the coke outlet of the coal gasifier, and the coke storage device is also connected to the inlet of the coal mill, and the outlet of the coal mill is connected to the main combustion zone of the boiler body of the power station boiler; wherein, The coal mill is used to grind coke into fine coke and transport the fine coke to the main combustion zone of the boiler body of the power station boiler.

3. The zero carbon emission system according to claim 2, characterized in that: The coal mill outlet includes a first fine coke nozzle and a second fine coke nozzle; The first and second fine coke nozzles are connected to the main combustion zone of the boiler body of the power station boiler, and the first and second fine coke nozzles are located between the first and second gasification gas nozzles.

4. The zero carbon emission system according to claim 3, characterized in that: The boiler body of the power station boiler is sequentially arranged with the main combustion zone, the reburning zone and the burnout zone from bottom to top.

5. The zero carbon emission system according to any one of claims 2 to 4, characterized in that: The zero-carbon emission system further includes an electrolytic water tank, an oxygen storage tank, a gas mixer and a first blower; The electrolytic water tank generates oxygen through new energy generation, and the oxygen enters the oxygen storage tank, which is connected to the gas mixer, and the gas mixer is also connected to the carbon dioxide storage tank; wherein, The gas mixer is used to mix the oxygen in the oxygen storage tank and part of the carbon dioxide in the carbon dioxide storage tank to generate primary air, secondary air and burnout air; The first fan is used to transport the primary air, secondary air and overburned air into the boiler body of the power station boiler.

6. The zero carbon emission system according to claim 5, characterized in that: The zero-carbon emission system further includes a first heat exchanger, a second heat exchanger, and an air preheater disposed in the boiler body; The first heat exchanger is connected to the gas mixer, and is used to transport the primary air to the first fan, and then transport the primary air to the air preheater through the first fan; The second heat exchanger is connected to the first heat exchanger, and is used to transport the secondary air and the overburned air to the first fan, and then transport the secondary air and the overburned air to the air preheater through the first fan.

7. The zero carbon emission system according to claim 6, characterized in that: The heat required for heat exchange in the first heat exchanger and the second heat exchanger is the dry quenching waste heat brought out by the inert gas in the coke storage device.

8. The zero carbon emission system according to claim 6, characterized in that: The zero-carbon emission system also includes an air-capture carbon dioxide device; The air-to-carbon dioxide capture device captures carbon dioxide by generating electricity using new energy, and transports the carbon dioxide to the carbon dioxide storage tank.

9. The zero carbon emission system according to any one of claims 1 to 4, characterized in that: The zero carbon emission system also includes a flue gas dust collector and a second fan; The flue gas dust collector and the second fan are sequentially arranged between the boiler body outlet of the power station boiler and the carbon dioxide storage tank; and the carbon dioxide discharged from the boiler body outlet of the power station boiler enters the carbon dioxide storage tank via the flue gas dust collector and the second fan in sequence.

10. A zero-carbon emission method for deep peak regulation of coal gasification coupled power plant boilers, characterized in that: Using the zero-carbon emission system according to any one of claims 1 to 9, the method comprises: When there is excess electricity generation from renewable energy, it will power the water electrolysis tank and the air capture carbon dioxide system respectively, and the generated hydrogen, oxygen and carbon dioxide will be stored in hydrogen storage tanks, oxygen storage tanks and carbon dioxide storage tanks respectively; A portion of the carbon dioxide in the carbon dioxide storage tank and a portion of the steam extracted from the turbine are mixed in a gasifying agent mixer to serve as a gasifying agent; Part of the hydrogen in the hydrogen storage tank is used to prepare ammonia, and the other part is prepared as liquid hydrogen and passed into the liquid hydrogen storage tank for storage; The oxygen in the oxygen storage tank and the carbon dioxide in the carbon dioxide storage tank are introduced into a gas mixer for thorough mixing to obtain an oxygen / carbon dioxide mixed gas as primary air, secondary air and burnout air; Under the action of the gasifying agent and coal, the coal gasifier produces gasification gas, tar, and coke; wherein the gasification gas is respectively fed into the main combustion zone and the reburning zone of the boiler body through the first gasification gas nozzle and the second gasification gas nozzle as combustion-supporting fuel and reburning fuel; the coke is first collected in the coke storage device, the large coke particles are collected as chemical products, and the small coke particles are crushed into fine coke in the coal mill and then fed into the main combustion zone of the boiler body for combustion; The primary air is preheated in the first heat exchanger, and the secondary air and the burnt air are preheated in stages in the first heat exchanger and the second heat exchanger; the heat required for preheating is the residual heat of the dry quenching of the coke carried out by the inert gas in the coke storage device; The tail flue gas passes through a flue gas dust collector and a fan and is then sent into the carbon dioxide storage tank for storage.

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