阅读说明：本技术 火电厂空分储能耦合富氧燃烧碳捕集一体化集成系统及方法 (Air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system and method for thermal power plant ) 是由 姬海民 薛宁 徐党旗 敬小磊 张知翔 于 2021-01-18 设计创作，主要内容包括：本发明公开了火电厂空分储能耦合富氧燃烧碳捕集一体化集成系统及方法,锅炉连接透平,透平连接发电机；发电机的输出端分为两路,一路能够与电网连接,一路与空分装置连接；空分装置与氧气储存罐以及防爆增压风机连接,空分装置与氧气储存罐的连接管路上以及空分装置与防爆增压风机连接的管路上分别设有第一防爆调节阀和第二防爆调节阀,氧气储存罐的出口与防爆增压风机连接且连接管路上设有第三防爆调节阀；送风机锅炉的氧气入口连接,防爆增压风机的出口与送风机出口连通；烟气处理系统与锅炉的烟气出口连接,尾气分离回收系统与烟气处理系统出口连接。本发明结构简单,即解决了深度调峰,又实现了碳减排且效果佳,整体经济效益较好。(The invention discloses an integrated system and a method for air separation energy storage coupling oxygen-enriched combustion carbon capture in a thermal power plant, wherein a boiler is connected with a turbine, and the turbine is connected with a generator; the output end of the generator is divided into two paths, one path can be connected with a power grid, and the other path is connected with an air separation device; the air separation device is connected with the oxygen storage tank and the explosion-proof booster fan, a first explosion-proof regulating valve and a second explosion-proof regulating valve are respectively arranged on a connecting pipeline of the air separation device and the oxygen storage tank and a pipeline of the air separation device connected with the explosion-proof booster fan, an outlet of the oxygen storage tank is connected with the explosion-proof booster fan, and a third explosion-proof regulating valve is arranged on the connecting pipeline; the oxygen inlet of the blower boiler is connected, and the outlet of the explosion-proof booster fan is communicated with the outlet of the blower; the flue gas treatment system is connected with a flue gas outlet of the boiler, and the tail gas separation and recovery system is connected with an outlet of the flue gas treatment system. The invention has simple structure, solves the problem of deep peak regulation, realizes carbon emission reduction, and has good effect and better overall economic benefit.)

1. An integrated system for air separation energy storage coupling oxygen-enriched combustion carbon capture in a thermal power plant is characterized by comprising a boiler (1), a turbine (2), a generator (3), an air separation device (9), an oxygen storage tank (11), an explosion-proof booster fan (12), a blower (13), a flue gas treatment system and a tail gas separation and recovery system, wherein the boiler (1) is connected with the turbine (2), and the turbine (2) is connected with the generator (3); the output end of the generator (3) is divided into two paths, one path can be connected with a power grid (6), and the other path is connected with an air separation device (9); the air separation device (9) is connected with the oxygen storage tank (11) and the explosion-proof booster fan (12), a first explosion-proof regulating valve (20) and a second explosion-proof regulating valve (23) are respectively arranged on a connecting pipeline of the air separation device (9) and the oxygen storage tank (11) and a pipeline of the air separation device (9) connected with the explosion-proof booster fan (12), an outlet of the oxygen storage tank (11) is connected with the explosion-proof booster fan (12), and a third explosion-proof regulating valve (22) is arranged on the connecting pipeline; an oxygen inlet of the boiler (1) of the blower (13) is connected, and an outlet of the explosion-proof booster fan (12) is communicated with an outlet of the blower (13); the flue gas treatment system is connected with a flue gas outlet of the boiler (1), the tail gas separation and recovery system is connected with an outlet of the flue gas treatment system, and the tail gas separation and recovery system is also connected with the generator (3).

2. The integrated system for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant according to claim 1, characterized in that a first inverter (4) and a first power switch (5) are arranged on one circuit of which the output end of the generator (3) can be connected with a power grid (6); and a second inverter (7) and a second power switch (8) are arranged on a line connecting the generator (3) and the air separation device (9).

3. The integrated system for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant as claimed in claim 1, wherein the outlet of the oxygen storage tank (11) is further provided with a pipeline connected with an oxygen user, and the pipeline is provided with a fourth explosion-proof regulating valve (21).

4. The integrated system for the air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant as claimed in claim 1, wherein the air separation plant (9) is further connected with a nitrogen storage tank (10), and a fifth explosion-proof regulating valve (18) is arranged on a pipeline connecting the air separation plant (9) and the nitrogen storage tank (10).

5. The thermal power plant air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system as claimed in claim 4, wherein the outlet of the nitrogen storage tank (10) is provided with a pipeline connected with a nitrogen user, and the pipeline is provided with a sixth explosion-proof regulating valve (19).

6. The thermal power plant air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system as claimed in claim 5, wherein the flue gas treatment system comprises a condenser (14), a dust removal device (15) and an integrated pollutant removal device (16), an inlet of the condenser (14) is connected with a flue gas outlet of the boiler (1), an inlet of the dust removal device (15) is connected with a gas outlet of the condenser (14), and a gas outlet of the dust removal device (15) is connected with a gas inlet of the integrated pollutant removal device (16).

7. The thermal power plant air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system is characterized in that the air separation device (9) comprises an air compressor, a heat exchanger, an expansion machine (28) and a first cryogenic distillation tower (29), the air compressor is connected with the heat exchanger, the heat exchanger is connected with the expansion machine (28), the expansion machine (28) is connected with the first cryogenic distillation tower (29), the air compressor is further connected with a generator (3), and a nitrogen outlet of the first cryogenic distillation tower (29) is connected with a nitrogen storage tank (10).

8. The thermal power plant air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system as claimed in claim 7, wherein the tail gas separation and recovery system comprises CO₂A compressor (17) and a second cryogenic distillation tower (30), wherein the inlet of the second cryogenic distillation tower (30) is connected with the gas outlet of the integrated pollutant removing device (16), and the second cryogenic distillation tower (30) is provided with a nitrogen outlet and CO₂The nitrogen outlet of the second cryogenic distillation tower (30) is connected with the nitrogen storage tank (10) to CO of the second cryogenic distillation tower (30)₂Outlet and CO₂Inlet connection of compressor (17), CO₂The compressor (17) is also connected with the generator (3) and the expander (28) respectively.

9. The integrated method for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant is implemented by the integrated system for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant according to any one of claims 1 to 8, and comprises the following processes:

connecting the output end of the generator (3) with a power grid;

when the thermal power generating unit needs deep peak shaving, the air separation unit (9) is enabled to work, the first explosion-proof regulating valve (20) and the second explosion-proof regulating valve (23) are opened, one part of oxygen obtained by the air separation unit (9) is stored in the oxygen storage tank (11), and the other part of oxygen is sent to the inlet of the explosion-proof booster fan (12); after being pressurized by an explosion-proof booster fan (12), oxygen is mixed at the outlet of a blower (13) and is sent to a boiler (1) together for eutrophication combustion;

when the power generation and supply requirements of the thermal power generating unit are increased, the air separation unit (9) stops working, the first explosion-proof regulating valve (20) and the second explosion-proof regulating valve (23) are closed, the third explosion-proof regulating valve (22) is opened, and oxygen in the oxygen storage tank (11) is sent to the inlet of the explosion-proof booster fan (12); after being pressurized by an explosion-proof booster fan (12), oxygen is mixed at the outlet of a blower (13) and is sent to a boiler (1) together for eutrophication combustion;

in the working process of the boiler (1), the tail gas of the boiler (1) is purified and decontaminated by a flue gas treatment system to obtain pure CO₂Mixed gas with nitrogen, pure CO₂And separating and recovering the mixed gas with the nitrogen by a tail gas separation and recovery system.

10. The integrated method for air separation energy storage coupling oxygen-enriched combustion carbon capture in the thermal power plant is characterized in that the air separation device (9) comprises an air compressor, a heat exchanger, an expansion machine (28) and a first cryogenic distillation tower (29), the air compressor is connected with the heat exchanger, the heat exchanger is connected with the expansion machine (28), the expansion machine (28) is connected with the first cryogenic distillation tower (29), and a nitrogen outlet of the first cryogenic distillation tower (29) is connected with a nitrogen storage tank (10); the tail gas separation and recovery system comprises CO₂A compressor (17) and a second cryogenic distillation tower (30), wherein the inlet of the second cryogenic distillation tower (30) is connected with the gas outlet of the integrated pollutant removing device (16), and the second cryogenic distillation tower (30) is provided with a nitrogen outlet and CO₂The nitrogen outlet of the second cryogenic distillation tower (30) is connected with the nitrogen storage tank (10) to CO of the second cryogenic distillation tower (30)₂Outlet and CO₂Inlet connection of compressor (17), CO₂The compressor (17) is also connected with the generator (3) and the expander (28) respectively;

when the thermal power generating unit needs deep peak shaving, the air compressor compresses air and utilizes the compressed airThe heat exchanger exchanges heat to ensure that the temperature of the compressed air reaches the working temperature of the expander (28), the expander (28) sends the compressed air into the first cryogenic distillation tower (29), the first cryogenic distillation tower (29) separates oxygen and nitrogen from the air, and the nitrogen enters the nitrogen storage tank (10); expander (28) driven CO₂The compressor (17) is operated; the second cryogenic distillation tower (30) feeds the separated nitrogen gas into a nitrogen storage tank (10) and separates CO₂Feeding CO₂The compressor (17) compresses and recovers;

when the power generation and supply demand of the thermal power generating unit increases, the expander (28) stops driving CO₂The compressor (17) is operated and the generator (3) drives CO₂The compressor (17) is operated; the second cryogenic distillation tower (30) feeds the separated nitrogen gas into a nitrogen storage tank (10) and separates CO₂Feeding CO₂The compressor (17) compresses and recovers the refrigerant.

Technical Field

The invention belongs to the field of deep peak regulation of a thermal power plant, and relates to an integrated system and method for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant.

Background

Aiming at the key policy requirements of carbon emission reduction proposed at present, the thermal power generating unit is the most important object for controlling carbon emission, and carbon emission reduction cannot be realized by using the traditional technology. With the change of national power policy in recent years, the main functions of the thermal power plant are changed at the same time, and the main power of power supply is changed into the main power of power supply to participate in the deep peak regulation in cooperation with a power grid. Meanwhile, the policy of subsidizing the electricity price of the advanced peak regulation of the national platform greatly stimulates the enthusiasm of the thermal power plant for carrying out the advanced peak regulation reconstruction of the unit. At present, thermal power faces the risk of excess of productivity and structurality, and new energy faces great consumption pressure. The thermal power is bound to give way for new energy development. Thermal power generating units are subject to deep peaking. For the 'three north' area, the wind-fire contradiction of the heating period is particularly prominent, the period with the best wind power resource is the winter heating period, in addition, the proportion of the provincial thermoelectric units is too high, peak-shaving power sources of other categories are relatively deficient, the continuously increased heating demand and the continuously increased clean energy installation are caused, and the peak-shaving space is very limited. Particularly, in northeast regions, most thermal power is combined heat and power generation units, the peak regulation capacity is only 10%, new energy storage consumption and new energy increment development are influenced, and a hard gap of the peak regulation capacity causes severe electricity limitation of new energy in partial regions, so that the thermoelectric units can realize deep peak regulation only through transformation.

At present, a unit participating in deep peak shaving runs for a long time deviating from a design value, so that the safety and the economy of the unit are reduced. However, the existing technical route which gives consideration to deep peak regulation and carbon emission reduction of the thermal power generating unit is still in an exploration stage, and an economical and feasible technical route is not provided.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system and method for a thermal power plant.

The technical scheme adopted by the invention is as follows:

the integrated system comprises a boiler, a turbine, a generator, an air separation device, an oxygen storage tank, an explosion-proof booster fan, a blower, a flue gas treatment system and a tail gas separation and recovery system, wherein the boiler is connected with the turbine which is connected with the generator; the output end of the generator is divided into two paths, one path can be connected with a power grid, and the other path is connected with an air separation device; the air separation device is connected with the oxygen storage tank and the explosion-proof booster fan, a first explosion-proof regulating valve and a second explosion-proof regulating valve are respectively arranged on a connecting pipeline of the air separation device and the oxygen storage tank and a pipeline of the air separation device connected with the explosion-proof booster fan, an outlet of the oxygen storage tank is connected with the explosion-proof booster fan, and a third explosion-proof regulating valve is arranged on the connecting pipeline; the oxygen inlet of the blower boiler is connected, and the outlet of the explosion-proof booster fan is communicated with the outlet of the blower; the flue gas treatment system is connected with a flue gas outlet of the boiler, the tail gas separation and recovery system is connected with an outlet of the flue gas treatment system, and the tail gas separation and recovery system is further connected with the generator.

Preferably, a first inverter and a first power switch are arranged on one path of line of the output end of the generator, which can be connected with a power grid.

Preferably, a second inverter and a second power switch are arranged on a line connecting the generator and the air separation unit.

Preferably, the outlet of the oxygen storage tank is also provided with a pipeline connected with an oxygen user, and the pipeline is provided with a fourth explosion-proof regulating valve.

Preferably, the air separation plant is further connected with a nitrogen storage tank, and a fifth explosion-proof regulating valve is arranged on a pipeline connecting the air separation plant and the nitrogen storage tank.

Preferably, the outlet of the nitrogen storage tank is provided with a pipeline connected with a nitrogen user, and the pipeline is provided with a sixth explosion-proof regulating valve.

Preferably, the flue gas treatment system comprises a condenser, a dust removal device and an integrated pollutant removal device, wherein an inlet of the condenser is connected with a flue gas outlet of the boiler, an inlet of the dust removal device is connected with a gas outlet of the condenser, and a gas outlet of the dust removal device is connected with a gas inlet of the integrated pollutant removal device.

Preferably, the air separation device comprises an air compressor, a heat exchanger, an expander and a first cryogenic distillation tower, the air compressor is connected with the heat exchanger, the heat exchanger is connected with the expander, the expander is connected with the first cryogenic distillation tower, the air compressor is further connected with a generator, and a nitrogen outlet of the first cryogenic distillation tower is connected with a nitrogen storage tank.

Preferably, the tail gas separation and recovery system comprises CO₂A compressor and a second cryogenic distillation tower, the inlet of the second cryogenic distillation tower is connected with the gas outlet of the integrated pollutant removal device, the second cryogenic distillation tower is provided with a nitrogen outlet and CO₂The outlet of the second cryogenic distillation tower is connected with the nitrogen storage tank and the CO of the second cryogenic distillation tower₂Outlet and CO₂Compressor inlet connection, CO₂The compressor is also connected with the generator and the expander respectively.

The invention also provides an integrated method for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant, which is implemented by the integrated system for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant, and comprises the following processes:

connecting the output end of the generator with a power grid;

when the thermal power generating unit needs deep peak shaving, the air separation unit is enabled to work, the first explosion-proof regulating valve and the second explosion-proof regulating valve are opened, one part of oxygen obtained by the air separation unit is stored in the oxygen storage tank, and the other part of oxygen is sent to the inlet of the explosion-proof booster fan; pressurizing oxygen by an explosion-proof booster fan, mixing the oxygen at the outlet of a blower, and feeding the oxygen and the air to a boiler for eutrophication combustion;

when the power generation and supply requirements of the thermal power generating unit are increased, the air separation unit stops working, the first explosion-proof regulating valve and the second explosion-proof regulating valve are closed, the third explosion-proof regulating valve is opened, and oxygen in the oxygen storage tank is sent into an inlet of the explosion-proof booster fan; pressurizing oxygen by an explosion-proof booster fan, mixing the oxygen at the outlet of a blower, and feeding the oxygen and the air to a boiler for eutrophication combustion;

in the working process of the boiler, the tail gas of the boiler is purified and decontaminated by a flue gas treatment system to obtain pure CO₂Mixed gas with nitrogen, pure CO₂And separating and recovering the mixed gas with the nitrogen by a tail gas separation and recovery system.

Preferably, the integrated method for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant further comprises a process of supplying redundant oxygen stored in the oxygen storage tank to an oxygen client;

the method also comprises a process of separating nitrogen by an air separation device and supplying the separated nitrogen to a nitrogen user.

Preferably, when the thermal power generating unit needs deep peak regulation, the air compressor compresses air and exchanges heat by using the heat exchanger, so that the temperature of the compressed air reaches the working temperature of the expansion machine, the expansion machine sends the compressed air into the first low-temperature distillation tower, the first low-temperature distillation tower separates oxygen and nitrogen from the air, and the nitrogen enters the nitrogen storage tank; expander driven CO₂The compressor works; the second cryogenic distillation tower feeds the separated nitrogen into a nitrogen storage tank, and the separated CO is fed into a nitrogen storage tank₂Feeding CO₂The compressor compresses and recovers;

when the power generation and supply demand of the thermal power generating unit increases, the expander stops driving CO₂The compressor is operated and the generator drives CO₂The compressor works; the second cryogenic distillation tower feeds the separated nitrogen into a nitrogen storage tank, and the separated CO is fed into a nitrogen storage tank₂Feeding CO₂The compressor compresses and recovers.

The invention has the following beneficial effects:

according to the integrated system for the thermal power plant air separation energy storage coupling oxygen-enriched combustion carbon capture, the air separation device is arranged, when the unit needs to carry out deep peak regulation, part of generated energy is absorbed by the air separation device, the air can be separated by using the air separation device, oxygen with high practical value is obtained, part of obtained oxygen can be stored by arranging the oxygen storage tank, and the air separation device can be stored by arranging the explosion-proof booster fan and the air feederAnd a part of sample gas obtained by separation is sent into the boiler for oxygen-enriched combustion, so that the boiler efficiency is improved, the pollutant emission is reduced, the carbon emission is reduced, and the overall economic benefit is high. When the unit needs the generated energy, steerable air separation plant stop work, can send the oxygen of storing in the oxygen storage tank into the boiler through explosion-proof booster fan and forced draught blower and carry out the oxygen boosting burning this moment, improve boiler efficiency, reduce the pollutant and discharge, reduce carbon and discharge, whole economic benefits is than. In conclusion, the air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system for the thermal power plant can perform oxygen-enriched combustion in both deep peak shaving and power generation demand, so that the utilization rate of fuel and the efficiency of the boiler are improved. In addition, the flue gas treatment system and the tail gas separation and recovery system can purify the boiler flue gas and nitrogen and CO in the boiler flue gas₂Is recovered so that CO produced by combustion₂The method can be used for trapping and sealing, reduces carbon emission, simultaneously recovers nitrogen brought by air during combustion, can be used for other purposes, improves the utilization rate of energy and reduces the waste of resources. In conclusion, the air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system for the thermal power plant can improve the boiler efficiency, reduce pollutant emission and carbon emission, has the characteristics of simple system, high energy utilization efficiency, large deep peak regulation potential and good carbon emission reduction and capture effects, and is high in safety and economical efficiency.

The method for integrating air separation energy storage coupling oxygen-enriched combustion and carbon capture in the thermal power plant can enable the boiler to carry out oxygen-enriched combustion when the thermal power unit needs deep peak shaving and when the power generation and supply requirements of the thermal power unit are increased, thereby improving the boiler efficiency, reducing the pollutant emission, and simultaneously carrying out CO treatment on the smoke₂The method has the advantages that the carbon emission is reduced by recycling, and simultaneously, nitrogen brought by air during combustion is recycled and can be used for other purposes, so that the utilization rate of energy is improved, and the overall economic benefit is better.

Drawings

FIG. 1 is a schematic structural diagram of an integrated system for air separation energy storage coupling oxygen-enriched combustion carbon capture in a thermal power plant.

FIG. 2 is a schematic view of the structure of an air separation plant according to the present invention.

Wherein, 1 is a boiler, 2 is a turbine, 3 is a generator, 4 is a first inverter, 5 is a first power switch, 6 is a power grid, 7 is a second inverter, 8 is a second power switch, 9 is an air separation device, 10 is a nitrogen storage tank, 11 is an oxygen storage tank, 12 is an explosion-proof booster fan, 13 is a blower, 14 is a condenser, 15 is a dust removal device, 16 is an integrated pollutant removal device, 17 is CO₂The system comprises a compressor, a fifth explosion-proof regulating valve 18, a sixth explosion-proof regulating valve 19, a first explosion-proof regulating valve 20, a fourth explosion-proof regulating valve 21, a third explosion-proof regulating valve 22, a second explosion-proof regulating valve 23, an air low-pressure compressor 24, a low-temperature heat exchanger 25, an air high-pressure compressor 26, a high-temperature heat exchanger 27, an expander 28, a first low-temperature distillation tower 29 and a second low-temperature distillation tower 30.

Detailed Description

The invention is further described below with reference to the figures and examples.

Referring to fig. 1, the air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system of the thermal power plant comprises a boiler 1, a turbine 2, a generator 3, an air separation device 9, an oxygen storage tank 11, an explosion-proof booster fan 12, a blower 13, a flue gas treatment system and a tail gas separation and recovery system, wherein the boiler 1 is connected with the turbine 2, and the turbine 2 is connected with the generator 3; the output end of the generator 3 is divided into two paths, one path can be connected with the power grid 6, and the other path is connected with the air separation device 9; the air separation device 9 is connected with the oxygen storage tank 11 and the explosion-proof booster fan 12, a first explosion-proof regulating valve 20 and a second explosion-proof regulating valve 23 are respectively arranged on a connecting pipeline of the air separation device 9 and the oxygen storage tank 11 and a pipeline of the air separation device 9 connected with the explosion-proof booster fan 12, an outlet of the oxygen storage tank 11 is connected with the explosion-proof booster fan 12, and a third explosion-proof regulating valve 22 is arranged on the connecting pipeline; the oxygen inlet of the boiler 1 is connected with a blower 13, and the outlet of the explosion-proof booster fan 12 is communicated with the outlet of the blower 13; the flue gas treatment system is connected with a flue gas outlet of the boiler 1, the tail gas separation and recovery system is connected with an outlet of the flue gas treatment system, and the tail gas separation and recovery system is also connected with the generator 3.

As a preferred embodiment of the present invention, a first inverter 4 and a first power switch 5 are provided on a line on which the output end of the generator 3 can be connected to the grid 6, and the on/off between the generator 3 and the grid 6 can be controlled by the first power switch 5.

As a preferred embodiment of the present invention, a second inverter 7 and a second power switch 8 are provided on a line connecting the generator 3 and the air separation unit 9, and the second inverter 7 and the second power switch 8 can supply power to the air separation unit 9 by the generator 3, so that the air separation unit 9 operates without additionally supplying power to the air separation unit 9, and the on/off circuit between the generator 3 and the air separation unit 9 can be controlled by the second power switch 8, and the air separation unit 9 is operated when the operation is required, and is stopped when the operation is not required.

As a preferred embodiment of the present invention, the outlet of the oxygen storage tank 11 is further provided with a pipeline connected to an oxygen user, the pipeline is provided with a fourth explosion-proof regulating valve 21, and excess oxygen stored in the oxygen storage tank 11 can be reasonably utilized through the pipeline and the fourth explosion-proof regulating valve 21, so that the cost is saved and a certain economic benefit can be created.

In a preferred embodiment of the present invention, the air separation unit 9 is further connected to a nitrogen storage tank 10, a fifth explosion-proof regulating valve 18 is arranged on a pipeline connecting the air separation unit 9 and the nitrogen storage tank 10, and the nitrogen separated from the air separation unit 9 can be stored by using the nitrogen storage tank 10 and then be used or sold, so that the cost can be saved and some economic benefits can be created.

As a preferred embodiment of the present invention, the outlet of the nitrogen storage tank 10 is provided with a pipeline connected to a nitrogen user, and the pipeline is provided with the sixth explosion-proof regulating valve 19, so that the nitrogen in the nitrogen storage tank 10 can be directly provided to the nitrogen user, creating a certain economic benefit.

As a preferred embodiment of the invention, the flue gas treatment system comprises a condenser 14, a dust removal device 15 and an integrated pollutant removal device 16, wherein the inlet of the condenser 14 is connected with the flue gas outlet of the boiler 1, the inlet of the dust removal device 15 is connected with the gas outlet of the condenser 14, and the gas outlet of the dust removal device 15 is connected with the gas inlet of the integrated pollutant removal device 16A port connection; can be with the aqueous vapor separation in the boiler flue gas and cool down the flue gas through condenser 14, can get rid of particulate matter in the flue gas after the cooling through dust collector 15, moisture, dust and pollutant desorption in the flue gas after the integration pollutant removal device can will remove dust, obtain pure CO₂And the tail gas separation and recovery system can separate pure CO obtained by treatment₂Is recycled for other use, realizes CO₂Emission reduction of (2) and simultaneous recovery of pure CO₂And certain economic benefit can be further generated, and the harm is changed into treasure.

As a preferred embodiment of the present invention, the air separation unit 9 comprises an air compressor, a heat exchanger, an expander 28 and a first cryogenic distillation tower 29, the air compressor is connected to the heat exchanger, the heat exchanger is connected to the expander 28, the expander 28 is connected to the first cryogenic distillation tower 29, the air compressor is further connected to the power generator 3, and a nitrogen outlet of the first cryogenic distillation tower 29 is connected to the nitrogen storage tank 10.

As a preferred embodiment of the present invention, the air separation plant 9 may be provided with a multi-stage air compressor and a heat exchanger, which are exemplified by a two-stage air compressor and a heat exchanger, wherein the two-stage air compressor and the heat exchanger include an air low-pressure compressor 24, a low-temperature heat exchanger 25, an air high-pressure compressor 26 and a high-temperature heat exchanger 27, the air low-pressure compressor 24, the low-temperature heat exchanger 25, the air high-pressure compressor 26 and the high-temperature heat exchanger 27 are sequentially connected, the high-temperature heat exchanger 27 is connected with an expander 28, a low-temperature distillation tower 29 is provided with a gas outlet, and both the air low-pressure compressor 24 and the air. The low-temperature heat exchanger 25 and the warm heat exchanger 27 can be arranged to cool the compressed air, so that the temperature of the compressed air meets the working requirement of the expansion machine, and meanwhile, the heat energy in the compressed air can be recycled through the refrigerants in the low-temperature heat exchanger 25 and the warm heat exchanger 27, so that energy conservation, emission reduction and effective utilization of energy are realized.

As a preferred embodiment of the present invention, the tail gas separation and recovery system comprises CO₂A compressor 17 and a second cryogenic distillation tower 30, the inlet of the second cryogenic distillation tower 30 and the gas outlet of the integrated pollutant removal device 16Connected, the second cryogenic distillation column 30 has a nitrogen outlet and CO₂An outlet, a nitrogen outlet of the second cryogenic distillation tower 30 and the nitrogen storage tank 10 are connected with the CO of the second cryogenic distillation tower 30₂Outlet and CO₂Compressor 17 inlet connection, CO₂The compressor 17 is also connected to the generator 3 and the expander 28, respectively.

The invention also provides an integrated method for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant, which is implemented by the integrated system for air separation energy storage coupling oxygen-enriched combustion carbon capture of the thermal power plant, and comprises the following processes:

connecting the output end of the generator 3 with a power grid;

when the thermal power generating unit needs deep peak shaving, the air separation unit 9 is enabled to work, the first explosion-proof regulating valve 20 and the second explosion-proof regulating valve 23 are opened, one part of oxygen obtained by the air separation unit 9 is stored in the oxygen storage tank 11, and the other part of oxygen is sent to the inlet of the explosion-proof booster fan 12; after being pressurized by an explosion-proof booster fan 12, oxygen is mixed at the outlet of a blower 13 and is sent to the boiler 1 together for eutrophication combustion;

when the power generation and supply requirements of the thermal power generating unit are increased, the air separation unit 9 stops working, the first explosion-proof regulating valve 20 and the second explosion-proof regulating valve 23 are closed, the third explosion-proof regulating valve 22 is opened, and oxygen in the oxygen storage tank 11 is sent to the inlet of the explosion-proof booster fan 12; after being pressurized by an explosion-proof booster fan 12, oxygen is mixed at the outlet of a blower 13 and is sent to the boiler 1 together for eutrophication combustion;

in the working process of the boiler 1, the tail gas of the boiler 1 is purified and decontaminated by a flue gas treatment system to obtain pure CO₂Mixed gas with nitrogen, pure CO₂And separating and recovering the mixed gas with the nitrogen by a tail gas separation and recovery system.

As a preferred embodiment of the present invention, when the air separation plant 9 and the off-gas separation and recovery system described above are employed in the present invention, that is, the air separation plant 9 comprises an air compressor, a heat exchanger, an expander 28 and a first cryogenic distillation column 29, the air compressor is connected to the heat exchanger, the heat exchanger is connected to the expander 28, the expander 28 is connected to the first cryogenic distillation column 29, and the first cryogenic distillation column 29 is connected to the first cryogenic distillation columnThe nitrogen outlet of the distillation tower 29 is connected with the nitrogen storage tank 10; the tail gas separation and recovery system comprises CO₂A compressor 17 and a second cryogenic distillation tower 30, wherein the inlet of the second cryogenic distillation tower 30 is connected with the gas outlet of the integrated pollutant removing device 16, and the second cryogenic distillation tower 30 is provided with a nitrogen outlet and a CO outlet₂An outlet, a nitrogen outlet of the second cryogenic distillation tower 30 and the nitrogen storage tank 10 are connected with the CO of the second cryogenic distillation tower 30₂Outlet and CO₂Compressor 17 inlet connection, CO₂The compressor 17 is also connected to the generator 3 and the expander 28, respectively;

when the thermal power generating unit needs deep peak shaving, the air compressor compresses air and exchanges heat by using the heat exchanger, so that the temperature of the compressed air reaches the working temperature of the expansion machine 28, the expansion machine 28 sends the compressed air into the first low-temperature distillation tower 29, the first low-temperature distillation tower 29 separates oxygen and nitrogen from the air, and the nitrogen enters the nitrogen storage tank 10; expander 28 driven CO₂The compressor 17 is operated; the second cryogenic distillation tower 30 feeds the separated nitrogen gas into the nitrogen storage tank 10 and the separated CO₂Feeding CO₂The compressor 17 compresses and recovers the refrigerant. In this embodiment, the expander can use the heat in the compressed air to perform external work to drive the CO₂The compressor 17 works, so that redundant energy in the air separation process can be fully utilized, and energy conservation and consumption reduction can be further realized.

When the power generation and supply demand of the thermal power generating unit increases, the expander 28 stops driving the CO₂The compressor 17 is operated and the generator 3 drives the CO₂The compressor 17 is operated; the second cryogenic distillation tower 30 feeds the separated nitrogen gas into the nitrogen storage tank 10 and the separated CO₂Feeding CO₂The compressor 17 compresses and recovers the refrigerant.

In the above embodiment, the CO in the treated pure off-gas can be removed by providing the second cryogenic distillation tower 30₂Separating with nitrogen to obtain CO₂Can be treated with CO₂The compressor 17 compresses the gas to be supplemented and utilized, and the obtained nitrogen can be stored and utilized by the nitrogen storage tank 10, so that the invention can also be used for storing and utilizing CO with higher purity in the tail gas₂And nitrogen gasAnd the complementary collection and resource utilization are carried out, so that the waste of resources is further reduced.

Examples

The integrated system for air separation energy storage coupling oxygen-enriched combustion carbon capture in the thermal power plant comprises a boiler 1, a turbine 2, a generator 3, a first inverter 4, a first power switch 5, a second inverter 7, a second power switch 8, an air separation device 9, a nitrogen storage tank 10, an oxygen storage tank 11, an explosion-proof booster fan 12, a blower 13, a condenser 14, a dust removal device 15, an integrated pollutant removal device 16, a CO (carbon monoxide) capture device₂A compressor 17, a second cryogenic distillation column 30 and a plurality of explosion-proof regulating valves; the boiler 1 is connected with a turbine 2, and the turbine 2 is connected with a generator 3. The generator 3 is divided into two paths, one path is connected with the rest power grid 6, and a first inverter 4 and a first power switch 5 are arranged on a connecting line between the generator 3 and the power grid 6; the other path of the generator 3 is connected with an air separation unit 9, and a second inverter 7 and a second power switch 8 are arranged on a line connected between the generator 3 and the air separation unit 9. The flue gas outlet of the boiler 1 is sequentially provided with condensed gas 14, a condenser 14, a dust removal device 15, an integrated pollutant removal device 16, a second low-temperature distillation tower 30 and CO along the flue gas flow direction₂A compressor 17, a nitrogen outlet of the second cryogenic distillation tower 30 and the nitrogen storage tank 10 are connected with the CO of the second cryogenic distillation tower 30₂Outlet and CO₂The compressor 17 is connected at the inlet. The outlet of the air separation device 9 is divided into three paths, and one path is connected with a fifth explosion-proof regulating valve 18, a nitrogen storage tank 10 and a sixth explosion-proof regulating valve 19 in sequence to a user; the second path is connected with a first explosion-proof regulating valve 20, an oxygen storage tank 11 and a fourth explosion-proof regulating valve 21 to a user in sequence; and the last path is connected with a second explosion-proof regulating valve 23 and is connected to the explosion-proof booster fan 12. The oxygen storage tank 11 is divided into two paths, one path is directly connected with the explosion-proof regulating valve 21 to a user, and the other path is connected with the explosion-proof regulating valve 22 to the inlet of the booster fan. The blower 13 is connected with the boiler 1 with the explosion-proof booster fan 12 to supply the oxidant for the boiler combustion. In this embodiment, the air separation unit 9 adopts the structural form of the two-stage air compressor and the heat exchanger.

The working method of the air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system of the thermal power plant comprises the following steps:

when the thermal power generating unit needs deep peak shaving, the second power switch 8 is closed, the air separation device 9 is powered on to work, the fifth explosion-proof regulating valve 18 is opened, nitrogen is stored in the nitrogen storage tank 10, and the sixth explosion-proof regulating valve 19 is opened for a user if the user needs the nitrogen constantly. The first explosion-proof regulating valve 20 and the second explosion-proof regulating valve 23 are opened, one part of oxygen is stored in the oxygen storage tank 11, and the other part of oxygen is directly fed into the inlet of the explosion-proof booster fan 12. After being pressurized by an explosion-proof booster fan 12, the mixture is mixed at the outlet of a blower 13 and is sent to the boiler 1 together for rich combustion. If the user needs oxygen at all times, the fourth explosion-proof regulating valve 21 is opened for the user to use, and the redundant oxygen is stored in the oxygen storage tank 11. When the air separation device 9 operates, the air low-pressure compressor 24 compresses air at normal temperature and normal pressure to 2-2.5Mpa, the temperature of the compressed air at the outlet of the air low-pressure compressor 24 is 510-560 ℃, the compressed air output by the air low-pressure compressor 24 exchanges heat through the low-temperature heat exchanger 25, and the temperature is controlled to be 200-250 ℃; the compressed air output by the low temperature heat exchanger 25 then enters the air high pressure compressor 26, the air high pressure compressor 26 compresses the air to 4-4.5Mpa, the temperature of the compressed air at the outlet of the air high pressure compressor 26 is 670-; after doing work, the pressure of the outlet exhaust of the expansion machine is 0.1-0.2Mpa, the temperature is 50-100 ℃, the expansion machine 28 sends the compressed air into a first cryogenic distillation tower 29 to separate oxygen and nitrogen, the nitrogen enters a nitrogen storage tank 10, a second cryogenic distillation tower 30 sends the separated nitrogen into the nitrogen storage tank 10, and the separated CO is sent to the nitrogen storage tank 10₂Feeding CO₂The compressor 17 compresses and recovers the refrigerant.

When the power generation and supply requirements of the thermal power generating unit increase, the second power switch 8 is switched off, the air low-pressure compressor 24, the air high-pressure compressor 26 and the expander 28 do not work any more, the boiler 1 operates alone to generate power, and simultaneously CO generates power₂The power source of the compressor 17 is switched to the power supply of the generator 3. Closing the fifth explosion-proof regulating valve 18. The first and second explosion-proof regulating valves 20 and 23 open the sixth and third explosion-proof regulating valves 19 and 22, and the nitrogen gas stored in the nitrogen gas storage tank 10 is used by the user. Oxygen stored in the oxygen storage tank 11 is mixed with air through the explosion-proof booster fan 12 and is sent into the furnace 1 for eutrophication combustion. At the moment, the boiler can still be ensured to be in an oxygen-enriched combustion stage, the boiler efficiency is improved, the pollutant emission is reduced, and the carbon emission is reduced.

No matter the thermal power generating unit has large power generation demand or needs deep peak regulation, the boiler combustion system is always in the oxygen-enriched combustion stage, and the combustion product contains more than 80 percent of CO₂The flue gas passes through a condenser 14 to condense all water in the flue gas, and then passes through a dust removal device 15 and an integrated pollutant removal device 16 to condense NO in the flue gas_x、SO₂Removing to obtain pure CO₂Mixed gas with nitrogen, pure CO₂The mixed gas with nitrogen is separated and separately recovered through the second cryogenic distillation tower 30, in which CO is passed₂The compressor 17 is trapped and sealed to reduce carbon emission, and the nitrogen is sent to the nitrogen storage tank 10 for resource utilization.

In conclusion, the air separation energy storage coupling oxygen-enriched combustion carbon capture integrated system of the thermal power plant is simple in structure, not only solves deep peak regulation, but also realizes carbon emission reduction, and is good in effect and good in overall economic benefit.