A coal-fired circulating fluidized bed boiler system co-firing biomass and sludge

Abstract

The present application relates to the technical field of coal-fired circulating fluidized bed boiler, and particularly relates to a coal-fired circulating fluidized bed boiler system for blending biomass and oil sludge, which comprises a biomass pretreatment system, an oil sludge pretreatment system, a biomass synthesis gas generation system and a circulating fluidized bed boiler, wherein the biomass pretreatment system, the oil sludge pretreatment system and the biomass synthesis gas generation system are respectively in communication with the inside of the circulating fluidized bed boiler; the biomass pretreatment system is used for dividing biomass into coarse biomass material and fine biomass material; the oil sludge pretreatment system is used for dividing oil sludge into dry oil sludge and wet oil sludge; and the biomass synthesis gas generation system takes the fine biomass material as input and is used for generating synthesis gas by reacting the fine biomass material with a gasification agent; thus, the combustion effect is enhanced, the cost is reduced, and the inside of the furnace is fully combusted.

Description

Technical Field

[0001] The invention relates to the technical field of coal-fired circulating fluidized bed boilers, in particular to a coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge. Background Art

[0002] Oilfield chemical companies often generate a large amount of oil sludge during production operations. Oil sludge is a hazardous waste that requires specialized treatment, which increases the burden on the company. Incineration is the most thorough method for sludge treatment, offering advantages such as rapid processing speed, high reduction, and resource reuse.

[0003] As a "zero-carbon" fuel, biomass can play a huge role in energy utilization. At present, many biomass power plants compress and thermoform biomass to make biomass into pellets for use. Although this method can increase the density and calorific value of biomass and facilitate the transportation and utilization of biomass, it has the following problems: (1) The compression and thermoforming of biomass will increase costs; (2) Biomass contains a large amount of alkali metals and alkaline earth metals. When burned and utilized, they will enter the gas phase and cause ash and slagging on the boiler heat exchange surface, seriously affecting the life of the boiler. These problems restrict the direct combustion and use of biomass. When biomass is gasified, some alkali metals remain in the coke, and the amount of precipitated into the gas phase is reduced, which can greatly alleviate the above problems. In addition, the utilization of syngas has good flexibility and excellent prospects.

[0004] Prior art CN110791347A discloses a sludge and biomass blending and processing system, comprising a feeding module, a sludge processing module, a solvent circulation module, a pellet forming module, and a control module; the feeding module is used to load biomass material and blend it with the sludge; the sludge processing module is used to dissolve the sludge to dilute it; the solvent circulation module is used to recover the solvent used in the sludge processing process; the pellet forming module is used to hot-press the mixture of sludge and biomass; and the control module is used to monitor and control the materials in the feeding module and the sludge processing module. The above system processes the sludge and biomass by hot-pressing the biomass and sludge to form pellet fuel, which is then fed into a circulating fluidized bed boiler for combustion. The hot-pressing operation increases costs, and the above system does not gasify the biomass. Feeding the pellet fuel into the circulating fluidized bed boiler for combustion may result in insufficient combustion or uneven combustion distribution in the circulating fluidized bed boiler.

[0005] Therefore, there is an urgent need to provide a coal-fired circulating fluidized bed boiler system that burns biomass and oil sludge. Compared with the existing technology, it can solve the problems of insufficient or uneven combustion of circulating fluidized bed boilers, as well as the problems of safety, environmental protection and high cost in oil sludge treatment. Summary of the Invention

[0006] The present invention solves the technical problems existing in the prior art and provides a coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A coal-fired circulating fluidized bed boiler system for co-firing biomass and oil sludge comprises a biomass pretreatment system, an oil sludge pretreatment system, a biomass synthesis gas generation system, and a circulating fluidized bed boiler, wherein the biomass pretreatment system, the oil sludge pretreatment system, and the biomass synthesis gas generation system are respectively connected to the interior of the circulating fluidized bed boiler;

[0009] The biomass pretreatment system is used to separate biomass into coarse biomass material and fine biomass material;

[0010] The oil sludge pretreatment system is used to separate the oil sludge into dry oil sludge and wet oil sludge;

[0011] The biomass synthesis gas generation system takes fine biomass as input and is used to react the fine biomass with a gasifying agent to generate synthesis gas.

[0012] Furthermore, the biomass syngas generation system includes a syngas generation furnace, a biomass char collection box and an electric heating area, wherein the biomass char collection box is provided at the lower end of the syngas generation furnace, and the electric heating area is located inside the syngas generation furnace;

[0013] A fine biomass inlet is provided at the syngas generator corresponding to the electric heating area, and the fine biomass inlet is connected to the biomass pretreatment system. A gasifying agent inlet is provided at the lower end of the side wall of the syngas generator, and the gasifying agent inlet is connected to the induced draft fan outlet. A syngas outlet is provided at the upper end of the syngas generator, and the syngas outlet is connected to the circulating fluidized bed boiler.

[0014] Furthermore, fine grates and coarse grates are sequentially arranged inside the synthesis gas generating furnace from bottom to top, and the fine grates and the coarse grates are arranged between the electric heating area and the biomass char collecting box.

[0015] Furthermore, two pipelines are connected between the fine biomass material inlet and the biomass pretreatment system, namely a main pipeline and a secondary pipeline. The main pipeline and the secondary pipeline are arranged in parallel. A fine material inlet electric valve is connected in series on the main pipeline, and a fine material inlet bypass manual valve and a fine material inlet bypass electric valve are connected in series on the secondary pipeline.

[0016] Furthermore, two pipelines are connected between the gasification agent inlet and the induced draft fan outlet, namely a main pipeline and a secondary pipeline. The main pipeline and the secondary pipeline are arranged in parallel. The main pipeline is connected in series with a gasification disturbance air outlet manual valve and a gasification disturbance air outlet electric valve, and the secondary pipeline is connected in series with a gasification disturbance air outlet bypass manual valve.

[0017] Furthermore, the aperture of the coarse grate is 100 The aperture of the fine grate is 50 .

[0018] Furthermore, the left and right walls of the circulating fluidized bed boiler furnace body are provided with gas charge inlets, which are arranged in the middle of the furnace body. The gas charge inlets are connected to the synthesis gas outlet through an annular gas supply pipe.

[0019] Furthermore, the sludge pretreatment system pretreats the sludge as follows: first, the sludge is placed in a sludge drying yard for drying, and then the sludge is divided into dry sludge and wet sludge according to the water content. The sludge with a water content less than or equal to 15% is dry sludge, and the sludge with a water content greater than 15% is wet sludge. The wet sludge is pumped into the sludge feeder through a sludge slurry pump for storage.

[0020] Furthermore, the outlet of the sludge feeder is connected to a first pipeline and a second pipeline respectively. The end of the first pipeline away from the sludge feeder is connected to the upper end of the furnace body of the circulating fluidized bed boiler, and the end of the second pipeline away from the sludge feeder is connected to the rear wall of the furnace body of the circulating fluidized bed boiler. The first pipeline is connected in series with a furnace top injection electric valve and a furnace top injection manual valve, and the second pipeline is connected in series with a furnace rear injection electric valve and a furnace rear injection manual valve.

[0021] Furthermore, the biomass pretreatment system pretreats the biomass as follows: first, the biomass is transported to the iron removal room to remove the iron blocks in the biomass, and then transported to the coarse crushing room and the fine crushing room in turn for crushing, and then the crushed biomass is divided into coarse biomass material and fine biomass material according to the size of the particle size. The particle size greater than 3 cm is coarse biomass material, and the particle size less than or equal to 3 cm is fine biomass material.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention separates oil sludge into dry oil sludge and wet oil sludge after pretreatment, separates biomass into coarse biomass material and fine biomass material after pretreatment, and then sends the fine biomass material bin into the synthesis gas generator to react with the gasifier to generate synthesis gas, and then respectively inputs the dry oil sludge, wet oil sludge, coarse biomass material and synthesis gas into the furnace for combustion. By mixing the biomass and oil sludge and reacting the biomass with the gasifier to form synthesis gas at the same time, it is beneficial to enhance the combustion effect, reduce costs, and ensure sufficient combustion inside the furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of the biomass and oil sludge pretreatment process of the present invention.

[0025] Figure 2 Schematic diagram of the biomass synthesis gas generation system of the present invention.

[0026] Figure 3 This is a schematic diagram of the biomass and oil sludge co-combustion system of the present invention.

[0027] Description of reference numerals:

[0028] 1. Coarse biomass silo; 2. Fine biomass silo; 3. Dry sludge silo; 4. Sludge slurry pump; 5. Sludge feeder; 6. Fine material inlet bypass manual valve; 7. Fine material inlet bypass electric valve; 8. Fine material inlet electric valve; 9. Electric heating area; 10. Coarse grate; 11. Fine grate; 12. Biomass char collection box; 13. Gasification disturbance air outlet manual valve; 14. Gasification disturbance air outlet electric valve; 15. Gasification disturbance air outlet bypass manual valve; 16. Synthesis gas storage tank; 17. Storage tank outlet valve; 18. Synthesis gas injection solenoid valve; 19. Top injection electric valve; 20. Top injection manual valve; 21. Back-furnace injection electric valve; 22. Back-furnace injection manual valve; 23. Synthesis gas outlet; 24. Coal drop pipe; 25. Air hood; 26. Return material air hood. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It should be noted that the orientation or position relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", etc. is based on the orientation or position relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0030] The present invention provides a coal-fired circulating fluidized bed boiler system for co-burning biomass and oil sludge, comprising a biomass pretreatment system, an oil sludge pretreatment system, a biomass synthesis gas generation system and a circulating fluidized bed boiler. The output ends of the biomass pretreatment system, the oil sludge pretreatment system and the biomass synthesis gas generation system are all connected to the circulating fluidized bed boiler. The biomass pretreatment system is used to distinguish between coarse biomass materials and fine biomass materials, the oil sludge pretreatment system is used to distinguish between wet oil sludge and dry oil sludge, the biomass synthesis gas generation system is used to generate biomass synthesis gas required for combustion in a combustion treatment system, and the circulating fluidized bed boiler is used to perform combustion treatment on the oil sludge, coarse biomass materials and the biomass synthesis gas.

[0031] Furthermore, the standard for the biomass pretreatment system to distinguish between coarse biomass and fine biomass is: particles with a diameter greater than 3 cm are coarse biomass, and particles with a diameter less than or equal to 3 cm are fine biomass; the standard for the sludge pretreatment system to distinguish between wet sludge and dry sludge is: particles with a moisture content greater than 15% are considered wet sludge, and particles with a moisture content less than or equal to 15% are considered dry sludge.

[0032] like Figure 1 As shown, the biomass pretreatment system will simply dry the biomass (corn stalks, cotton stalks, etc.) collected from the surrounding areas and then enter the iron removal room, coarse crushing room and fine crushing room in sequence for biomass processing. According to the particle size (diameter), the processed biomass enters the coarse biomass silo 1 and the fine biomass silo 2 respectively. Particles with a diameter greater than 3 cm are considered coarse biomass and enter the coarse biomass silo 1; particles with a diameter less than or equal to 3 cm are considered fine biomass and enter the fine biomass silo 2.

[0033] The biomass first passes through the iron removal room to remove iron from the material. This has two purposes: first, iron entering the coarse biomass silo 1 and entering the furnace through the belt coal feeder may scratch the belt, or even cut it in serious cases; second, iron entering the fine biomass silo 2 may clog or damage the syngas generator grate. The biomass then passes through the coarse crushing room and the fine crushing room for crushing.

[0034] The sludge pretreatment system first places sludge in a sludge drying yard for airing. Wet sludge is then separated into dry sludge based on its moisture content. Wet sludge with a moisture content greater than 15% is considered wet and is sent to a wet sludge silo. Sludge slurry pump 4 then pumps the wet sludge from the silo into sludge feeder 5 for storage. Sludge with a moisture content of 15% or less is considered dry and is sent to dry sludge silo 3. Petrochemical companies generate large amounts of sludge during their production processes. This sludge is collected and placed in a drying yard for treatment. Unlike the coal sludge and sewage sludge currently used in many power plants, oil sludge is much more viscous than coal sludge and therefore cannot be used as a reference for coal sludge (moisture content ≤30%, fed into the furnace via the coal sludge system).

[0035] like Figure 2As shown, the biomass syngas generation system includes a syngas generation furnace, a coarse grate 10, a fine grate 11, a biomass char collection box 12 and an electric heating area 9. A fine biomass material inlet is provided on the side wall of the syngas generation furnace. The fine biomass material inlet end is connected to the fine biomass material silo 2. Two pipelines are connected between the fine biomass material inlet and the fine biomass material silo 2, one of which is a main pipeline and the other is a secondary pipeline. The main pipeline and the secondary pipeline are arranged in parallel. A fine material inlet electric valve 8 is connected in series to the main pipeline, and a fine material inlet bypass manual valve 6 and a fine material inlet bypass electric valve 7 are connected in series to the secondary pipeline. The secondary pipeline is operated when the main pipeline fails or is under maintenance; the syngas generation furnace A biomass char collection box 12 is located at the lower end of the syngas generator. Inside the syngas generator, from bottom to top, are a fine grate 11, a coarse grate 10, and an electric heating area 9. The fine grate 11 is located above the biomass char collection box 12. Two gasifying agent inlets are located at the lower end of the syngas generator, opposite each other and located between the fine grate 11 and the coarse grate 10. The syngas generator operates on the principle of biomass gasification. Biomass is gasified at high temperatures with a gasifying agent (carbon dioxide, water vapor, and air) to produce a syngas with a high calorific value. The main components of the syngas are carbon monoxide, methane, and hydrogen. The gasifying agent is sourced from the induced draft fan outlet. This is because the exhaust gas at the induced draft fan outlet has been desulfurized and denitrified, and its main components are carbon dioxide, water vapor, and a small amount of air. Relevant research has shown that when carbon dioxide and water vapor are used as biomass gasifying agents, the syngas contains higher levels of carbon monoxide and hydrogen, and has a higher calorific value. After passing through the filter, the gasifying agent is fed into the syngas generator. Two pipelines connect the induced draft fan outlet to the syngas generator: a main pipeline and a secondary pipeline. The main and secondary pipelines are arranged in parallel, with the secondary pipeline's gasifying agent output end joining the main pipeline's gasifying agent output end. The main pipeline's gasifying agent output end is connected to the two gasifying agent inlets of the syngas generator. A manual gasification disturbance air outlet valve 13 and an electric gasification disturbance air outlet valve 14 are connected in series to the main pipeline, while a manual gasification disturbance air outlet bypass valve 15 is connected in series to the secondary pipeline. The secondary pipeline is used in the event of a main pipeline failure or maintenance. Several syngas outlets 23 are provided at the top of the syngas generator, connecting the syngas generator to a syngas storage tank 16 via these outlets.

[0036] The gasifying agent is introduced into the syngas generator through the bottom of the furnace. Two layers of grates are arranged inside the furnace: fine grate 11 has a pore size of 50 μm, and coarse grate 10 has a pore size of 100 μm. After biomass gasification, biochar (particle size <50 μm) that meets the required particle size is collected in a biochar collection box 12. The gasifying agent enters the syngas generator from the bottom, which not only ensures thorough mixing of the biomass and the gasifying agent but also provides a certain degree of agitation, causing repeated collisions between the biomass and between the biomass and the grates. This further exposes the biomass's interior and allows for wider contact with the gasifying agent. This results in a biochar with a better specific surface area and pore structure. Biochar, also known as biochar, is a material with a large specific surface area and a fine pore structure. After modification and activation under certain conditions, it can be used to adsorb heavy metals and other substances in soil, making it economically valuable. The electric heating area 9 is the reaction area of ​​the biomass and the gasifying agent, and is heated by electric heating, and its power supply can be taken from a 6KV plant transformer.

[0037] like Figure 3 As shown, a circulating fluidized bed boiler includes a furnace body, a coal feeder, an air preheater, a desulfurization tower, and a bag filter. A solid charge inlet is located slightly below the sidewall of the furnace body, and a gas charge inlet is located in the middle of the sidewall. The solid charge inlet is connected to the coal feeder via a coal drop pipe 24. A dry sludge silo 3, a coal silo, and a coarse biomass silo 1 are located above the feeder tracks. The solid charge introduced into the furnace body includes dry sludge, coal, and coarse biomass. A pipeline connects the upper end of the furnace body to the sludge feeder 5, which is located above the furnace body. Its outlet is divided into two pipelines. The first pipeline connects to the top of the furnace body, and is connected in series with a top injection electric valve 19 and a top injection manual valve 20. The second pipeline connects to the rear wall of the furnace, and is connected in series with a back-injection electric valve 21 and a back-injection manual valve 22. Because sludge is easily combustible, it has low pyrolysis temperature, initial combustion temperature, and burnout temperature, and the time required for complete combustion is also short. Oil sludge contains a high water content. When burned in the furnace, this water evaporates, removing some heat from the fuel bed (directly affecting the bed temperature). This change can affect boiler stability. Furthermore, changes in flue gas volume and fly ash concentration after co-firing oil sludge can alter heat transfer, ash accumulation, and wear on the convection heating surfaces in the tail flue. Therefore, when co-firing oil sludge and biomass in a circulating fluidized bed boiler, the co-firing amount must be appropriately allocated based on the fuel properties.

[0038] The left and right walls of the central section of the furnace are each equipped with a syngas injection solenoid valve 18. Both inlets are supplied with gas through an annular gas supply pipe that runs around the furnace. The inlet ends of the annular gas supply pipe are connected to a syngas storage tank 16, and the pipe connecting the syngas storage tank 16 and the annular gas supply pipe is connected in series with a tank outlet valve 17. Syngas is delivered to the dilute phase of the circulating fluidized bed boiler for combustion. This is because most circulating fluidized bed boilers have platen superheaters and reheaters located at the front of the furnace. If syngas were injected through holes in the front wall of the furnace, the structure would be too compact and could easily overheat the platen heating surfaces. Therefore, gas inlets are provided on the left and right walls of the furnace, each equipped with a syngas injection solenoid valve 18. Gas is supplied by an annular gas supply pipe that runs around the furnace, and the amount of gas supplied is determined by the temperature distribution in the dilute phase of the furnace.

[0039] A water-cooled air chamber is provided at the lower end of the furnace body, and a hood 25 is provided at the upper end of the water-cooled air chamber. The furnace body is also connected to the cyclone separator, and a return hood 26 is provided at the lower end of the cyclone separator. The gas after combustion inside the furnace body passes through the cyclone separator, air preheater, and desulfurization tower in sequence and enters the bag dust collector. Finally, the gas is discharged into the atmosphere through a chimney connected to the bag dust collector, and the solid enters the ash bin through the bag dust collector.

[0040] The working principle of the coal-fired circulating fluidized bed boiler system for co-firing biomass and oil sludge provided by the present invention is as follows: the oil sludge is pre-treated and divided into dry oil sludge and wet oil sludge, and the biomass is then pre-treated and divided into coarse biomass material and fine biomass material, and the fine biomass material is then sent into a synthesis gas generator to react with a gasifying agent to generate synthesis gas, and then the dry oil sludge, wet oil sludge, coarse biomass material and synthesis gas are respectively input into the furnace for combustion. By co-firing biomass and oil sludge and simultaneously converting the biomass into synthesis gas, it is beneficial to enhance the combustion effect, reduce costs, and ensure sufficient combustion inside the furnace.

[0041] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A coal-fired circulating fluidized bed boiler system for burning biomass and oil sludge, characterized in that: It includes a biomass pretreatment system, an oil sludge pretreatment system, a biomass synthesis gas generation system and a circulating fluidized bed boiler, wherein the biomass pretreatment system, the oil sludge pretreatment system and the biomass synthesis gas generation system are respectively connected to the interior of the circulating fluidized bed boiler; The biomass pretreatment system is used to separate biomass into coarse biomass material and fine biomass material; The oil sludge pretreatment system is used to separate the oil sludge into dry oil sludge and wet oil sludge; The biomass synthesis gas generation system takes fine biomass as input and is used to react the fine biomass with a gasifying agent to generate synthesis gas; The crude biomass, dry oil sludge and coal are fed into the lower part of the circulating fluidized bed boiler for combustion; the wet oil sludge is fed into the upper part of the circulating fluidized bed boiler for combustion; and the generated synthesis gas is fed into the inner part of the circulating fluidized bed boiler for combustion.

2. The coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge according to claim 1, characterized in that: The biomass syngas generation system includes a syngas generation furnace, a biomass char collection box and an electric heating area. The biomass char collection box is provided at the lower end of the syngas generation furnace, and the electric heating area is located inside the syngas generation furnace. A fine biomass inlet is provided at the syngas generator corresponding to the electric heating area, and the fine biomass inlet is connected to the biomass pretreatment system. A gasifying agent inlet is provided at the lower end of the side wall of the syngas generator, and the gasifying agent inlet is connected to the induced draft fan outlet. A syngas outlet is provided at the upper end of the syngas generator, and the syngas outlet is connected to the circulating fluidized bed boiler.

3. The coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge according to claim 2, characterized in that: A fine grate and a coarse grate are sequentially arranged inside the synthesis gas generating furnace from bottom to top, and the fine grate and the coarse grate are arranged between the electric heating area and the biomass char collecting box.

4. The coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge according to claim 3, characterized in that: Two pipelines are connected between the fine biomass inlet and the biomass pretreatment system, namely a main pipeline and a secondary pipeline. The main pipeline and the secondary pipeline are arranged in parallel. A fine material inlet electric valve is connected in series on the main pipeline, and a fine material inlet bypass manual valve and a fine material inlet bypass electric valve are connected in series on the secondary pipeline.

5. The coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge according to claim 3, characterized in that: Two pipelines are connected between the gasifying agent inlet and the induced draft fan outlet, namely a main pipeline and a secondary pipeline. The main pipeline and the secondary pipeline are arranged in parallel. A gasification disturbance air outlet manual valve and a gasification disturbance air outlet electric valve are connected in series on the main pipeline, and a gasification disturbance air outlet bypass manual valve is connected in series on the secondary pipeline.

6. The coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge according to claim 3, characterized in that: The aperture of the coarse grate is 100 The aperture of the fine grate is 50 .

7. The coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge according to claim 2, characterized in that: The left and right walls of the circulating fluidized bed boiler furnace body are both provided with gas charge inlets, which are arranged in the middle of the furnace body. The gas charge inlets are connected to the synthesis gas outlet through an annular gas supply pipe.

8. The coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge according to claim 1, characterized in that: The sludge pretreatment system pre-treats the sludge as follows: first place the sludge in the sludge drying yard for drying, and then separate the sludge into dry sludge and wet sludge according to the water content. The sludge with a water content of less than or equal to 15% is dry sludge, and the sludge with a water content of more than 15% is wet sludge. The wet sludge is pumped into the sludge feeder through the sludge slurry pump for storage.

9. The coal-fired circulating fluidized bed boiler system for mixing biomass and oil sludge according to claim 8, characterized in that: The outlet of the sludge feeder is connected to the first pipeline and the second pipeline respectively. The end of the first pipeline away from the sludge feeder is connected to the upper end of the circulating fluidized bed boiler furnace body, and the end of the second pipeline away from the sludge feeder is connected to the rear wall of the furnace body of the circulating fluidized bed boiler. The first pipeline is connected in series with the furnace top injection electric valve and the furnace top injection manual valve, and the second pipeline is connected in series with the furnace rear injection electric valve and the furnace rear injection manual valve.

10. The coal-fired circulating fluidized bed boiler system for co-firing biomass and oil sludge according to claim 1, characterized in that: The biomass pretreatment system pretreats biomass as follows: first, the biomass is transported to the iron removal room to remove the iron blocks in the biomass, and then transported to the coarse crushing room and the fine crushing room in sequence for crushing. The crushed biomass is then divided into coarse biomass and fine biomass according to the size of the particle size. The particle size greater than 3 cm is coarse biomass, and the particle size less than or equal to 3 cm is fine biomass.

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