A new type of coal-fired boiler biomass blending system

Abstract

The utility model provides a kind of new coal-fired boiler biomass blending combustion system, including the air preheater being arranged in boiler, bypass flue is arranged on the boiler in the air preheater, the other end of bypass flue is connected biomass carbon making and crushing equipment, biomass carbon making and crushing equipment are connected with biomass raw material feed inlet, the outlet of biomass carbon making and crushing equipment is connected biomass carbon storehouse by biomass carbon conveying belt, the outlet of biomass carbon storehouse is provided coal feeder, the end of coal feeder is connected to pulverized coal burner by coal feeder falling tube, and pulverized coal burner is arranged in boiler.The utility model is made into the biomass carbon of convenient storage and transport by using power plant heat source to biomass raw material, according to boiler load requirement, by secondary air into pulverized coal burner, realize and boiler blending combustion.The utility model avoids the jam problem in the process of biomass fuel crushing and conveying, realizes coal-fired unit clean carbon reduction.The utility model can be applied in new coal-fired power station or active unit blending combustion modification.

Description

Technical Field

[0001] This utility model relates to biomass co-firing technology, specifically to a novel biomass co-firing system for coal-fired boilers, which can be applied to newly built coal-fired units and carbon reduction retrofits of existing units. Background Technology

[0002] Against the backdrop of next-generation coal-fired power technology, new requirements have been put forward for clean carbon reduction in coal-fired power units. Coal-fired units are the main source of carbon emissions, while biomass is a zero-carbon emission fuel. Blending biomass with coal is the main means of reducing carbon emissions using biomass. However, due to the wide availability of biomass sources, its long fibers, and significant differences in moisture content, blockage problems during biomass crushing and transportation lead to unsatisfactory direct combustion of biomass. Utility Model Content

[0003] The technical problem to be solved by this utility model is: how to solve the blockage problem generated during the crushing and transportation of biomass, and therefore a new biomass co-firing system for coal-fired boilers is provided.

[0004] To solve the above problems, this utility model is achieved through the following technical solution: A novel biomass co-firing system for a coal-fired boiler includes an air preheater installed inside the boiler. A bypass flue is installed on the boiler next to the air preheater. The other end of the bypass flue is connected to a biomass carbonization and crushing device. The biomass carbonization and crushing device is connected to a biomass feed inlet. The outlet of the biomass carbonization and crushing device is connected to a biomass carbon silo via a biomass carbon conveyor belt. A coal feeder is installed at the outlet of the biomass carbon silo. The end of the coal feeder is connected to a pulverized coal burner via a coal feeder drop pipe. The pulverized coal burner is installed inside the boiler.

[0005] A boiler bypass flue damper is installed on the bypass flue.

[0006] The outlet of the biomass carbon bin is connected to the coal feeder via a carbon discharge pipe, and a carbon gate is installed on the carbon discharge pipe.

[0007] The coal feeder's downpipe is connected to the secondary air duct and the pulverized coal inlet duct, respectively. The secondary air duct is connected to the secondary air main pipe, and the pulverized coal inlet duct is connected to the pulverized coal burner.

[0008] A shut-off damper and a regulating damper are installed on the secondary air duct; a biomass char quick-closing damper is installed on the char powder inlet duct.

[0009] Compared with existing technologies, this invention has the following advantages: This invention utilizes the heat source within the power plant to process biomass raw materials into easily stored and transportable biomass carbon. Based on boiler load requirements, this carbon is then fed into the pulverized coal burner via secondary air for co-firing with the boiler. This invention avoids the problems of biomass fuel crushing and clogging during transportation, achieving clean carbon reduction in coal-fired power units. This invention can be applied to newly built coal-fired power plants or the co-firing retrofitting of existing units. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the present invention. Detailed Implementation

[0011] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0012] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0013] like Figure 1 As shown, a novel biomass co-firing system for a coal-fired boiler includes an air preheater 1 installed inside a boiler 11. A bypass flue 101 is installed on the boiler next to the air preheater 1. The other end of the bypass flue 101 is connected to a biomass carbon production and crushing device 3. The biomass carbon production and crushing device 3 is connected to a biomass raw material inlet 13. The outlet of the biomass carbon production and crushing device 3 is connected to a biomass carbon bin 4 via a biomass carbon conveyor belt 102. A coal feeder 6 is installed at the outlet of the biomass carbon bin 4. The end of the coal feeder 6 is connected to a pulverized coal burner 10 via a coal feeder drop pipe 104. The pulverized coal burner 10 is installed inside the boiler 11.

[0014] The biomass carbonization and crushing equipment 3 here includes biomass carbonization equipment and crushing equipment. The biomass carbonization equipment is commercially available equipment, such as the technical solution of a high-efficiency, environmentally friendly and energy-saving biomass carbonization unit as described in CN201820974864.7. The crushing equipment is also existing equipment, such as a crusher.

[0015] Furthermore, a boiler bypass flue damper 2 is installed on the bypass flue 101.

[0016] Furthermore, the outlet of the biomass carbon bin 4 is connected to the coal feeder 6 via a carbon dropping pipe 103, and a carbon gate 5 is installed on the carbon dropping pipe 103.

[0017] Furthermore, the coal feeder's downpipe 104 is connected to the secondary air duct 105 and the pulverized coal inlet duct 106, respectively. The secondary air duct 105 is connected to the secondary air main pipe 12, and the pulverized coal inlet duct 106 is connected to the pulverized coal burner 10. More preferably, a shut-off damper 7 and a regulating damper 8 are provided on the secondary air duct 105; and a biomass pulverized coal quick-closing damper 9 is provided on the pulverized coal inlet duct 106.

[0018] The working principle and process of this utility model are as follows: Flue gas is drawn from the bypass flue 101 on one side of the boiler hollow preheater 1 to provide a heat source for the biomass carbonization and crushing equipment 3. The opening of the boiler bypass flue damper 2 is adjusted to control the heat entering the biomass carbonization and crushing equipment 3. After entering the plant, the biomass enters the biomass carbonization and crushing equipment 3, where it undergoes drying, pyrolysis, and carbonization processes within a temperature range of 300~400℃ (this varies depending on the type of biomass) to produce biomass carbon. In the biomass carbonization and crushing equipment 3, the biomass carbon is crushed to the particle size required by the boiler burner, and then transported via the biomass carbon conveyor belt 102 to the biomass carbon silo 4 for storage. According to the boiler combustion requirements, when biomass carbon needs to enter the furnace for combustion, the shut-off damper 7 on the secondary air duct 105 is opened, the opening of the regulating damper 8 is adjusted, the biomass carbon quick-closing valve 9 is opened, and the carbon gate 5 is opened. The biomass carbon falls to the coal feeder 6, and enters the furnace pulverized coal inlet pipe 106 through the coal feeder drop pipe 104. Secondary air is used as the conveying medium to transport the biomass carbon powder into the pulverized coal burner for combustion. Biomass carbon has a high calorific value, and the independent pulverized coal burner 10 is beneficial for optimizing the burner's air distribution and ensuring complete combustion.

[0019] This invention utilizes the heat source within the power plant to process biomass raw materials into biomass carbon, which is convenient for storage and transportation. Based on boiler load requirements, this carbon is then fed into a pulverized coal burner via secondary air for co-firing with the boiler. This invention avoids the problems of biomass fuel crushing and blockage during transportation, achieving clean carbon reduction in coal-fired power units. This invention can be applied to newly built coal-fired power plants or the co-firing retrofitting of existing units.

[0020] The above description is only a preferred embodiment of the present utility model. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present utility model, and these should also be considered within the protection scope of the present utility model.

Claims

1. A novel biomass co-firing system for coal-fired boilers, characterized in that: The system includes an air preheater (1) installed in a boiler (11), a bypass flue (101) installed on the boiler next to the air preheater (1), the other end of the bypass flue (101) is connected to a biomass carbon production and crushing equipment (3), the biomass carbon production and crushing equipment (3) is connected to a biomass raw material inlet (13), the outlet of the biomass carbon production and crushing equipment (3) is connected to a biomass carbon bin (4) via a biomass carbon conveyor belt (102), a coal feeder (6) is installed at the outlet of the biomass carbon bin (4), and the end of the coal feeder (6) is connected to a pulverized coal burner (10) via a coal feeder drop pipe (104), and the pulverized coal burner (10) is installed in the boiler (11).

2. The novel biomass co-firing system for a coal-fired boiler according to claim 1, characterized in that: A boiler bypass flue damper (2) is installed on the bypass flue (101).

3. The novel biomass co-firing system for a coal-fired boiler according to claim 1, characterized in that: The outlet of the biomass carbon bin (4) is connected to the coal feeder (6) through the carbon drop pipe (103), and a carbon gate (5) is installed on the carbon drop pipe (103).

4. The novel biomass co-firing system for a coal-fired boiler according to claim 1, characterized in that: The coal feeder drop pipe (104) is connected to the secondary air pipe (105) and the pulverized coal inlet pipe (106) respectively. The secondary air pipe (105) is connected to the secondary air main pipe (12), and the pulverized coal inlet pipe (106) is connected to the pulverized coal burner (10).

5. A novel biomass co-firing system for a coal-fired boiler according to claim 4, characterized in that: A shut-off valve (7) and a regulating valve (8) are installed on the secondary air duct (105); a biomass carbon quick-closing valve (9) is installed on the char powder inlet duct (106).

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