Chemical looping system coupled with high-capacity thermal power generating unit
By introducing a coupled chemical chain system into a large-capacity thermal power unit, the chemical chain reaction is used to enrich CO2 and recover waste heat, the problem of high CO2 emissions of thermal power units is solved, and the effect of reducing carbon emissions and recovering waste heat is achieved without affecting the normal operation of the unit.
Patent Information
- Application Number
- CN202411641316.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-18
- Publication Date
- 2025-03-07
AI Technical Summary
The CO2 emissions of large-capacity thermal power units are huge, the existing post-combustion capture technology is costly, and the chemical chain combustion technology has not yet been implemented for engineering applications, making it difficult to reduce the carbon emissions of thermal power units.
A chemical chain system coupled with a large capacity thermal power unit is proposed, including an air reactor, a fuel reactor, a CO2 purification device, etc., which enriches high concentration of CO2 through chemical chain reaction, and recovers the waste heat of the chemical chain into the condensate system of the thermal power unit.
High concentration of CO2 is achieved, reducing carbon emissions of thermal power units; by recovering waste heat from the chemical chain, the unit coal consumption is not increased; and the normal operation of thermal power units does not affect the thermal power units.
Smart Images
Figure CN119573045A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of carbon emission reduction, and specifically relates to a chemical chain system coupled with a large-capacity thermal power unit. Background Art
[0002] At present, CO2 emissions from my country's power industry account for a high proportion of the country's total emissions, among which thermal power generation accounts for the bulk of the country's total power generation. Reducing CO2 emissions from thermal power units is of great significance to the power industry.
[0003] Large-capacity thermal power units have huge CO2 emissions, with a single unit emitting millions of tons of CO2 per year. Conventional thermal power units mainly use suspended combustion, fluidized bed combustion, and fixed bed combustion. Suspended combustion and fluidized bed combustion are the main combustion methods for large-capacity thermal power units. At present, some large-capacity thermal power units in service or under construction in China need to reduce a certain amount of CO2 emissions. Most power plants use post-combustion capture technology and add a CO2 capture system at the tail of the boiler. Due to the low concentration of CO2 in the flue gas, the carbon capture cost of this system is relatively high. Chemical chaining is a new type of combustion technology, which mainly includes an air reactor and a fuel reactor. In the air reactor, the oxygen carrier reacts with oxygen in the air to generate a high-valent oxygen carrier. Through the transportation of the oxygen carrier, the oxygen element is sent to the fuel reactor. In the fuel reactor, the fuel reacts with oxygen in the high-valent oxygen carrier to generate a low-valent oxygen carrier, CO2 and H2O. The low-valent oxygen carrier is sent back to the air reactor, and the flue gas is condensed to obtain a high-concentration CO2.
[0004] In theory, chemical chain combustion technology can be used to replace the existing large-capacity unit suspension combustion or fluidized bed combustion technology to enrich CO2 while producing high-parameter steam. However, chemical chain combustion technology has not yet been applied in engineering, and it is extremely difficult to build a new large-capacity chemical chain combustion thermal power unit. Therefore, this application proposes a chemical chain system solution for coupling large-capacity thermal power units, which can reduce the carbon emissions of thermal power units without affecting the operation of thermal power units. Summary of the invention
[0005] In order to reduce the CO2 emissions of large-capacity thermal power units, this application provides a chemical chain system coupled with large-capacity thermal power units. This application can enrich high-concentration CO2 and reduce the carbon emissions of thermal power units; the waste heat of the chemical chain can be recovered through the unit condensate system without increasing the coal consumption of the unit; whether the chemical chain is put into operation or not does not affect the normal operation of the thermal power unit.
[0006] The purpose of this application is achieved through the following technical solutions:
[0007] A chemical chain system coupled with a large-capacity thermal power unit comprises an air reactor, wherein the upper part of the air reactor is connected to a first gas-solid separator, the lower part of the first gas-solid separator is connected to a first material return device, the first material return device is connected to a fuel reactor, the fuel reactor is connected to an overflow pipe, the overflow pipe is connected to the lower part of the air reactor, the air reactor and the fuel reactor are filled with oxygen carriers; and the upper part of the fuel reactor is connected to a CO2 purification device.
[0008] Furthermore, it also includes a condenser and a low-pressure cylinder, the low-pressure cylinder is connected to the low-pressure cylinder steam extraction pipeline, the low-pressure cylinder steam extraction pipeline is connected to the low-pressure heater, the condenser is respectively connected to the condensate outlet pipe and the low-pressure heater, the condensate outlet pipe is connected to the first branch pipe, the first branch pipe is provided with a first regulating valve, and the first branch pipe is connected to the condensate inlet pipe through the condensate channel of the air reactor.
[0009] Furthermore, a steam regulating valve is provided on the low-pressure cylinder steam extraction pipeline, and the condensate inlet pipe is connected to the low-pressure heater and the water pump.
[0010] Furthermore, the upper part of the fuel reactor is connected to the second gas-solid separator, the lower part of the second gas-solid separator is connected to the second material return device, the second material return device is connected to the fuel reactor, the upper part of the second gas-solid separator is connected to the second heat exchanger, the second heat exchanger is connected to the second flue gas purification device, and the second flue gas purification device is connected to the CO2 purification device.
[0011] Furthermore, the condensate outlet pipe is connected to a third branch pipe, a third regulating valve is provided on the third branch pipe, and the third branch pipe is connected to the condensate inlet pipe through a condensate channel of the second heat exchanger.
[0012] Furthermore, the upper portion of the first gas-solid separator is connected to the first heat exchanger, the first heat exchanger is connected to the first flue gas purification device, and the first flue gas purification device is connected to the chimney.
[0013] Furthermore, the condensate outlet pipe is connected to a second branch pipe, a second regulating valve is provided on the second branch pipe, and the second branch pipe is connected to the condensate inlet pipe through a condensate channel of the first heat exchanger.
[0014] Furthermore, the air reactor adopts a water-cooled membrane wall structure, and the internal temperature does not exceed 1100°C; the fuel reactor adopts an insulating structure, and the internal temperature is not lower than 800°C.
[0015] Furthermore, a casting material is laid inside the air reactor, and the casting material is made of high silicon carbide material.
[0016] Furthermore, when the air reactor and fuel reactor of the chemical chain unit are shut down, the condenser and low-pressure cylinder of the thermal power unit operate in normal mode; when the air reactor and fuel reactor of the chemical chain unit are operating, part of the condensate of the condenser of the thermal power unit is heated by the chemical chain unit, and the steam extraction amount of the low-pressure cylinder is reduced by adjusting the steam regulating valve, so as to control the condensate temperature at the outlet of the low-pressure heater to be maintained at the same level as when operating in normal mode.
[0017] Beneficial effects of this application:
[0018] 1. It can enrich high-concentration CO2 and reduce carbon emissions from thermal power units.
[0019] 2. The waste heat of the chemical chain can be recovered through the unit's condensing water system without increasing the unit's coal consumption.
[0020] 3. Whether the chemical chain is put into operation or not will not affect the normal operation of the thermal power unit.
[0021] The aforementioned main scheme of the present application and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection in the present application; and in the present application, (non-conflicting options) can also be freely combined with each other and with other options. After understanding the scheme of the present application, those skilled in the art can understand that there are many combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present application, and they are not exhaustively listed here. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a schematic diagram of the structure of this application.
[0023] In the figure: 1-air reactor, 2-first gas-solid separator, 3-first return device, 4-fuel reactor, 5-overflow pipe, 51-oxygen carrier, 6-second gas-solid separator, 7-second return device, 8-condenser, 9-low-pressure cylinder, 10-low-pressure heater, 11-condensate outlet pipe, 12-first branch pipe, 13-second branch pipe, 14-third branch pipe, 15-condensate inlet pipe, 16-low-pressure cylinder steam extraction pipeline, 21-first regulating valve, 22-second regulating valve, 23-third regulating valve, 24-steam regulating valve, 31-first heat exchanger, 32-first flue gas purification device, 33-chimney, 41-second heat exchanger, 42-second flue gas purification device, 43-CO2 purification device. DETAILED DESCRIPTION
[0024] The following non-limiting examples are provided to illustrate the present application.
[0025] Example 1
[0026] refer to Figure 1As shown, a chemical chain system coupled with a large-capacity thermal power unit includes an air reactor 1, a first gas-solid separator 2, a first return device 3, a fuel reactor 4, an overflow pipe 5, an oxygen carrier 51, a second gas-solid separator 6, a second return device 7, a condenser 8, a low-pressure cylinder 9, a low-pressure heater 10, a condensate outlet pipe 11, a first branch pipe 12, a second branch pipe 13, a third branch pipe 14, a condensate inlet pipe 15, a low-pressure cylinder steam extraction pipeline 16, a first regulating valve 21, a second regulating valve 22, a third regulating valve 23, a steam regulating valve 24, a first heat exchanger 31, a first flue gas purification device 32, a chimney 33, a second heat exchanger 41, a second flue gas purification device 42 and a CO2 purification device.
[0027] The upper part of the air reactor 1 is connected to the first gas-solid separator 2, the first gas-solid separator 2 is a cyclone separator, the lower part of the first gas-solid separator 2 is connected to the first return device 3, the first return device 3 is connected to the fuel reactor 4, the fuel reactor 4 is connected to the overflow pipe 5, the overflow pipe 5 is connected to the lower part of the air reactor 1, the air reactor 1 and the fuel reactor 4 are filled with oxygen carriers 51, and the above components constitute a circulation loop of the oxygen carrier 51 of the chemical chain unit.
[0028] The oxygen carrier in the air reactor 1 is oxidized to release a large amount of heat, and the main reaction formula is: Me x O y +O2→Me x O y+1 Therefore, the air reactor 1 adopts a water-cooled membrane wall structure to control the temperature of the air reactor to not exceed 1100°C. The oxygen carrier in the fuel reactor 4 is reduced by the fuel, and the overall reaction is endothermic. The main reaction formula is: Me x O y+1 +C m H n →Me x O y +CO2+H2O, so the fuel reactor 4 adopts an insulating structure, and the temperature of the fuel reactor 4 is not less than 800°C. In order to avoid the wear of the oxygen carrier 51 on the air reactor 1, a 20-70mm thick castable is laid inside the air reactor 1. The castable is made of high silicon carbide material with a thermal conductivity of 0.5-20W / m·K.
[0029] The upper part of the fuel reactor 4 is connected to the second gas-solid separator 6, which is a cyclone separator, and the lower part of the second gas-solid separator 6 is connected to the second material return device 7, which is connected to the fuel reactor 4. The first gas-solid separator 2 and the second gas-solid separator 6 perform gas-solid separation on the exhausted flue gas, the oxygen carrier sinks to be recycled, and the flue gas rises and is discharged for the next step of utilization.
[0030] The condenser 8 and the low-pressure cylinder 9 are thermal power units. The low-pressure cylinder 9 is connected to the low-pressure cylinder steam extraction pipeline 16, and the low-pressure cylinder steam extraction pipeline 16 is connected to the low-pressure heater 10. The condenser 8 is respectively connected to the condensate outlet pipe 11 and the low-pressure heater 10. The low-pressure cylinder steam extraction pipeline 16 is provided with a steam regulating valve 24 for controlling the steam extraction amount of the low-pressure cylinder.
[0031] The condensate outlet pipe 11 is connected to the first branch pipe 12, the second branch pipe 13, and the third branch pipe 14 respectively. The first branch pipe 12 is provided with a first regulating valve 21. The first branch pipe 12 is connected to the condensate inlet pipe 15 through the condensate channel of the air reactor 1 to absorb the heat of the air reactor 1.
[0032] The upper part of the first gas-solid separator 2 is connected to the first heat exchanger 31, the first heat exchanger 31 is connected to the first flue gas purification device 32, and the first flue gas purification device 32 is connected to the chimney 33. The condensate outlet pipe 11 is connected to the second branch pipe 13, and the second branch pipe 13 is provided with a second regulating valve 22. The second branch pipe 13 is connected to the condensate inlet pipe 15 through the condensate channel of the first heat exchanger 31 to cool the flue gas at the outlet of the air reactor 1.
[0033] The upper part of the second gas-solid separator 6 is connected to the second heat exchanger 41, the second heat exchanger 41 is connected to the second flue gas purification device 42, and the second flue gas purification device 42 is connected to the CO2 purification device 43. The condensate outlet pipe 11 is connected to the third branch pipe 14, and the third branch pipe 14 is provided with a third regulating valve 23. The third branch pipe 14 is connected to the condensate inlet pipe 15 through the condensate channel of the second heat exchanger 41 to cool the flue gas at the outlet of the fuel reactor 4.
[0034] The condensed water inlet pipe 15 is connected to the water pump after merging with the low-pressure heater 10. After the condensed water in the three-way branch pipe is heated, it is collected in the condensed water inlet pipe 15, which is connected to the outlet pipe of the low-pressure heater 10, and the merged condensed water is sent to the water pump.
[0035] The first branch pipe 12 is provided with a first regulating valve 21, the second branch pipe 13 is provided with a second regulating valve 22, and the third branch pipe 14 is provided with a third regulating valve 23, which are used to regulate the flow of condensed water entering each branch. By controlling the flow of condensed water in each branch pipe, the temperature of the condensed water after heating in each branch pipe is made lower than the saturation temperature by more than 20°C.
[0036] When the air reactor 1 and the fuel reactor 4 of the chemical chain unit are shut down, the condenser 8 and the low-pressure cylinder 9 of the thermal power unit operate in the normal mode; when the air reactor 1 and the fuel reactor 4 of the chemical chain unit are operating, part of the condensate of the condenser 8 of the thermal power unit is heated by the chemical chain unit, and the steam extraction amount of the low-pressure cylinder 9 is reduced by adjusting the steam regulating valve 24, and the condensate temperature at the outlet of the low-pressure heater 10 is controlled to be maintained at the same level as when operating in the normal mode.
[0037] Example 2
[0038] refer to Figure 1 As shown, a chemical chain system coupled with a large-capacity thermal power unit includes an air reactor 1, a first gas-solid separator 2, a first return device 3, a fuel reactor 4, an overflow pipe 5, an oxygen carrier 51, a second gas-solid separator 6, a second return device 7, a condenser 8, a low-pressure cylinder 9, a low-pressure heater 10, a condensate outlet pipe 11, a first branch pipe 12, a second branch pipe 13, a third branch pipe 14, a condensate inlet pipe 15, a low-pressure cylinder steam extraction pipeline 16, a first regulating valve 21, a second regulating valve 22, a third regulating valve 23, a steam regulating valve 24, a first heat exchanger 31, a first flue gas purification device 32, a chimney 33, a second heat exchanger 41, a second flue gas purification device 42 and a CO2 purification device.
[0039] The upper part of the air reactor 1 is connected to the first gas-solid separator 2, the first gas-solid separator 2 is a cyclone separator, the lower part of the first gas-solid separator 2 is connected to the first return device 3, the first return device 3 is connected to the fuel reactor 4, the fuel reactor 4 is connected to the overflow pipe 5, the overflow pipe 5 is connected to the lower part of the air reactor 1, the air reactor 1 and the fuel reactor 4 are filled with oxygen carriers 51, and the above components constitute a circulation loop of the oxygen carrier 51 of the chemical chain unit.
[0040] The oxygen carrier in the air reactor 1 is oxidized to release a large amount of heat, and the main reaction formula is: Me x O y +O2→Me x O y+1 Therefore, the air reactor 1 adopts a water-cooled membrane wall structure to control the temperature of the air reactor to not exceed 1100°C. The oxygen carrier in the fuel reactor 4 is reduced by the fuel, and the overall reaction is endothermic. The main reaction formula is: Me x O y+1 +C m H n →Me x O y +CO2+H2O, so the fuel reactor 4 adopts an insulating structure and the temperature of the fuel reactor 4 is not lower than 800°C.
[0041] To prevent the oxygen carrier 51 from wearing the air reactor 1, a 25-35 mm thick casting material is laid inside the air reactor 1, preferably 25 mm thick. The casting material is made of high silicon carbide material with a thermal conductivity of 1.5-7.5 W / m·K, preferably 3 W / m·K.
[0042] The upper part of the fuel reactor 4 is connected to the second gas-solid separator 6, which is a cyclone separator, and the lower part of the second gas-solid separator 6 is connected to the second material return device 7, which is connected to the fuel reactor 4. The first gas-solid separator 2 and the second gas-solid separator 6 perform gas-solid separation on the exhausted flue gas, the oxygen carrier sinks to be recycled, and the flue gas rises and is discharged for the next step of utilization.
[0043] The condenser 8 and the low-pressure cylinder 9 are thermal power units. The low-pressure cylinder 9 is connected to the low-pressure cylinder steam extraction pipeline 16, and the low-pressure cylinder steam extraction pipeline 16 is connected to the low-pressure heater 10. The condenser 8 is respectively connected to the condensate outlet pipe 11 and the low-pressure heater 10. The low-pressure cylinder steam extraction pipeline 16 is provided with a steam regulating valve 24 for controlling the steam extraction amount of the low-pressure cylinder.
[0044] The condensate outlet pipe 11 is connected to the first branch pipe 12, the second branch pipe 13, and the third branch pipe 14 respectively. The first branch pipe 12 is provided with a first regulating valve 21. The first branch pipe 12 is connected to the condensate inlet pipe 15 through the condensate channel of the air reactor 1 to absorb the heat of the air reactor 1.
[0045] The upper part of the first gas-solid separator 2 is connected to the first heat exchanger 31, the first heat exchanger 31 is connected to the first flue gas purification device 32, and the first flue gas purification device 32 is connected to the chimney 33. The condensate outlet pipe 11 is connected to the second branch pipe 13, and the second branch pipe 13 is provided with a second regulating valve 22. The second branch pipe 13 is connected to the condensate inlet pipe 15 through the condensate channel of the first heat exchanger 31 to cool the flue gas at the outlet of the air reactor 1.
[0046] The upper part of the second gas-solid separator 6 is connected to the second heat exchanger 41, the second heat exchanger 41 is connected to the second flue gas purification device 42, and the second flue gas purification device 42 is connected to the CO2 purification device 43. The condensate outlet pipe 11 is connected to the third branch pipe 14, and the third branch pipe 14 is provided with a third regulating valve 23. The third branch pipe 14 is connected to the condensate inlet pipe 15 through the condensate channel of the second heat exchanger 41 to cool the flue gas at the outlet of the fuel reactor 4.
[0047] The condensed water inlet pipe 15 is connected to the water pump by merging with the low-pressure heater 10. After the condensed water in the three-way branch pipe is heated, it is collected in the condensed water inlet pipe 15, which is connected to the outlet pipe of the low-pressure heater 10, and the merged condensed water is sent to the water pump.
[0048] The first branch pipe 12 is provided with a first regulating valve 21, the second branch pipe 13 is provided with a second regulating valve 22, and the third branch pipe 14 is provided with a third regulating valve 23, which are used to regulate the flow of condensed water entering each branch. By controlling the flow of condensed water in each branch pipe, the temperature of the condensed water after heating in each branch pipe is made lower than the saturation temperature by more than 20°C.
[0049] When the air reactor 1 and the fuel reactor 4 of the chemical chain unit are shut down, the condenser 8 and the low-pressure cylinder 9 of the thermal power unit operate in the normal mode; when the air reactor 1 and the fuel reactor 4 of the chemical chain unit are operating, part of the condensate of the condenser 8 of the thermal power unit is heated by the chemical chain unit, and the steam extraction amount of the low-pressure cylinder 9 is reduced by adjusting the steam regulating valve 24, and the condensate temperature at the outlet of the low-pressure heater 10 is controlled to be maintained at the same level as when operating in the normal mode.
[0050] The aforementioned basic examples and their further selected examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed for protection in this application. In the scheme of this application, each selected example can be arbitrarily combined with any other basic examples and selected examples.
[0051] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims
1. A chemical chain system coupled to a large-capacity thermal power unit, comprising an air reactor (1), characterized in that: The upper part of the air reactor (1) is connected to the first gas-solid separator (2), the lower part of the first gas-solid separator (2) is connected to the first return material device (3), the first return material device (3) is connected to the fuel reactor (4), the fuel reactor (4) is connected to the overflow pipe (5), the overflow pipe (5) is connected to the lower part of the air reactor (1), the air reactor (1) and the fuel reactor (4) are filled with oxygen carriers (51); the upper part of the fuel reactor (4) is connected to the CO2 purification device (43).
2. The chemical chaining system for coupling large-capacity thermal power units according to claim 1 is characterized in that: The invention also includes a condenser (8) and a low-pressure cylinder (9), wherein the low-pressure cylinder (9) is connected to a low-pressure cylinder extraction pipeline (16), and the low-pressure cylinder extraction pipeline (16) is connected to a low-pressure heater (10). The condenser (8) is respectively connected to a condensate outlet pipe (11) and a low-pressure heater (10), and the condensate outlet pipe (11) is connected to a first branch pipe (12). A first regulating valve (21) is provided on the first branch pipe (12), and the first branch pipe (12) is connected to a condensate inlet pipe (15) through a condensate channel of an air reactor (1).
3. The chemical chaining system for coupling large-capacity thermal power units according to claim 2 is characterized in that: The low-pressure cylinder steam extraction pipeline (16) is provided with a steam regulating valve (24), and the condensate introduction pipe (15) is connected to the low-pressure heater (10) and the water pump.
4. The chemical chaining system for coupling large-capacity thermal power units according to claim 1 or 2, characterized in that: The upper part of the fuel reactor (4) is connected to the second gas-solid separator (6), the lower part of the second gas-solid separator (6) is connected to the second return material (7), the second return material (7) is connected to the fuel reactor (4), the upper part of the second gas-solid separator (6) is connected to the second heat exchanger (41), the second heat exchanger (41) is connected to the second flue gas purification device (42), and the second flue gas purification device (42) is connected to the CO2 purification device (43).
5. The chemical chaining system for coupling large-capacity thermal power units according to claim 2 is characterized in that: The condensate outlet pipe (11) is connected to the third branch pipe (14), a third regulating valve (23) is provided on the third branch pipe (14), and the third branch pipe (14) is connected to the condensate inlet pipe (15) through the condensate channel of the second heat exchanger (41).
6. The chemical chaining system for coupling large-capacity thermal power units according to claim 1 or 2, characterized in that: The upper part of the first gas-solid separator (2) is connected to the first heat exchanger (31), the first heat exchanger (31) is connected to the first flue gas purification device (32), and the first flue gas purification device (32) is connected to the chimney (33).
7. The chemical chaining system for coupling large-capacity thermal power units according to claim 2 is characterized in that: The condensate outlet pipe (11) is connected to the second branch pipe (13), a second regulating valve (22) is provided on the second branch pipe (13), and the second branch pipe (13) is connected to the condensate inlet pipe (15) through the condensate channel of the first heat exchanger (31).
8. The chemical chaining system for coupling large-capacity thermal power units according to claim 1 is characterized by: The air reactor (1) adopts a water-cooled membrane wall structure, and the internal temperature does not exceed 1100°C; the fuel reactor (4) adopts an insulating structure, and the internal temperature is not lower than 800°C.
9. The chemical chaining system for coupling large-capacity thermal power units according to claim 1 or 8, characterized in that: The air reactor (1) is internally provided with a casting material, and the casting material is made of high silicon carbide material.
10. The chemical chaining system for coupling large-capacity thermal power units according to claim 1 is characterized in that: When the air reactor (1) and the fuel reactor (4) of the chemical chain unit are shut down, the condenser (8) and the low-pressure cylinder (9) of the thermal power unit operate in a normal mode; when the air reactor (1) and the fuel reactor (4) of the chemical chain unit are in operation, part of the condensate of the condenser (8) of the thermal power unit is heated by the chemical chain unit, and the steam extraction amount of the low-pressure cylinder (9) is reduced by adjusting the steam regulating valve (24), and the condensate temperature at the outlet of the low-pressure heater (10) is controlled to be maintained at the same level as when operating in the normal mode.