Low-load combustion device of coal-fired unit
By designing a mixing component and a gas guide block buffer structure in the coal-fired unit, the problems of combustion instability and internal wall impact during low-load operation were solved, thus achieving combustion stability and boiler protection.
Patent Information
- Application Number
- CN202520014120.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-04
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2035-01-04
AI Technical Summary
When existing coal-fired power units operate at low loads, the combustion of pulverized coal in the boiler is unstable, making it prone to flameout. Furthermore, the high-temperature gas severely impacts the inner wall of the boiler, indicating that existing stable combustion technology has shortcomings.
A low-load combustion device for a coal-fired unit was designed, including a coal mill, a gasifier, and a boiler. The high-temperature gas is mixed with unburned ultrafine coal powder by a mixing component and then fed into the boiler. The coal powder is ignited by a high-energy igniter, and the gas flow is buffered by a gas guide block and a transition chamber to reduce the impact on the inner wall of the boiler.
This achieves complete combustion of pulverized coal in the boiler and reduces the impact on the boiler's inner wall, thereby improving combustion stability and extending the boiler's service life.
Smart Images
Figure CN223726335U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to coal -fired machine technical field especially relates to a coal -fired unit low load combustion device. BACKGROUND
[0002] Coal -fired power plant is the main source of carbon dioxide emissions, under the pressure of carbon emission reduction, the construction of the new type electric power system with renewable energy as the main body is the strategic decision of the country. But wind power, solar power generation exists intermittency, volatility, random characteristics, and the peak valley ratio of power generation is huge, and the stability of power grid is poor, and solving the large proportion of new energy consumption is the urgent problem that electric power system needs to solve. Coal -fired unit has the characteristics of wide load operation and flexible start-stop, therefore, the flexible reconstruction of thermal power, and the peak regulation of coal -fired unit is the inevitable requirement to guarantee the stable supply of electric power.
[0003] When coal -fired unit is in deep peak regulation low load operation, the coal powder in the boiler is greatly reduced, the air coal ratio increases greatly, and the relative coal combustion heat is greatly reduced, which can cause the furnace temperature to reduce, the flame burning stability to reduce, and the boiler to be prone to fireout. It is difficult to maintain stable combustion by adjusting the operation parameters of the boiler. At present, the low load combustion auxiliary technology of coal -fired boiler mainly includes auxiliary fuel oil, gas combustion stabilization technology, plasma combustion stabilization technology, oxygen-enriched combustion stabilization technology and air preheating combustion stabilization technology.
[0004] In most of the low load combustion devices of the existing coal -fired unit, the high-temperature gas of the gasification furnace and the superfine coal powder are directly injected into the boiler, which is easy to cause impact on the inner wall of the boiler, and the oxygen content of the injected gas is low, which is not conducive to combustion. UTILITY MODEL CONTENTS
[0005] The utility model discloses a low load combustion device of coal -fired unit to solve the defects in the prior art.
[0006] In order to realize the above-mentioned purpose, the utility model adopts the following technical scheme:
[0007] A low load combustion device of coal -fired unit, including the coal mill, gasification furnace and boiler that are sequentially arranged, the coal mill is connected with gasification furnace through the fourth pipe, the gasification furnace is connected with the mixing assembly through the first pipe, the mixing assembly is fixedly connected on the boiler and communicates with the inside of the boiler, and the second pipe is also arranged on the mixing assembly, the mixing assembly includes the outer tube, the outer tube is provided with the gas guide block at the middle position, the gas guide block is provided with the conversion cavity, the conversion cavity communicates with the second pipe, and the side wall of the conversion cavity is provided with the gas outlet.
[0008] Further, the outer tube interior includes a transition cavity and a combination cavity, the inner diameter of the transition cavity gradually increases from one side of the first pipe to the other side; the air guide block near one side of the first pipe is a circular truncated cone structure, and the circular truncated cone side of the air guide block is arranged in the transition cavity.
[0009] Further, the fifth pipe is arranged on the coal mill, the fifth pipe is used for air inlet, a filter cavity is arranged on the fifth pipe, a mounting hole is formed on the filter cavity, a mounting frame is detachably arranged on the mounting hole, and a filter plate is fixedly connected to the mounting frame.
[0010] Further, the gasification furnace is provided with a combination cavity on the top, the combination cavity is provided with a fourth pipe and a third pipe, and the air inlet direction of the fourth pipe is perpendicular to the air inlet direction of the third pipe.
[0011] Further, the hole channel of the air outlet hole is obliquely arranged, and the oblique direction of the hole channel is opposite to the air inlet direction of the first pipe.
[0012] Beneficial effects
[0013] Compared with the prior art, the beneficial effects of the present application are that the coal-fired unit low-load combustion device provided by the present application can make the high-temperature combustion gas carrying unburned ultrafine coal powder fully mix with the air passing through and then enter the boiler, so as to fully burn the coal powder, and can also buffer the high-temperature combustion gas carrying unburned ultrafine coal powder, so as to slow down the impact on the inner wall of the boiler. BRIEF DESCRIPTION OF DRAWINGS
[0014] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation on the present application.
[0015] Figure 1 It is a whole structure schematic view of the coal-fired unit low-load combustion device.
[0016] Figure 2 It is a structure schematic view of the mixing assembly.
[0017] Figure 3 It is a structure schematic view of the filter cavity.
[0018] In the drawings: 1, boiler; 2, mixing assembly; 3, first pipe; 4, second pipe; 5, gasification furnace; 6, third pipe; 7, fourth pipe; 8, coal mill; 9, fifth pipe;
[0019] 21, transition cavity; 22, air guide block; 23, conversion cavity; 24, air outlet hole;
[0020] 91, mounting frame; 92, filter plate; 93, filter cavity. DETAILED DESCRIPTION
[0021] The technical solutions in the embodiments of the utility model will be apparently and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments.
[0022] In the description of the utility model, it needs to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as limiting the utility model in indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model.
[0023] Reference Figure 1 - Figure 3 A kind of coal-fired unit low load combustion device, including sequentially arranged coal mill 8, gasification furnace 5 and boiler 1;Coal mill 8 is connected with gasification furnace 5 by fourth pipeline 7, gasification furnace 5 is connected with mixing assembly 2 by first pipeline 3, mixing assembly 2 is fixedly connected on boiler 1, and with the inside of boiler 1 intercommunication, second pipeline 4 is also provided on mixing assembly 2;Mixing assembly 2 includes outer tube, outer tube is provided with guide block 22 at middle position, guide block 22 is provided with conversion cavity 23, conversion cavity 23 is communicated with second pipeline 4, and the side wall of conversion cavity 23 is provided with gas outlet 24.
[0024] In work, raw coal is sent into coal mill 8, and raw coal is ground into superfine coal powder by the mechanism in coal mill 8, air is adjusted to carry superfine coal powder from the fourth pipeline 7 at the top of superfine coal mill 8 into gasification furnace 5, high-pressure air is introduced into the bottom of coal mill 8 to carry superfine coal powder from the top of gasification furnace 5 into gasification furnace 5, and high-energy igniter is used to ignite superfine coal powder after being introduced;High-temperature water vapor and air mixture is introduced into third pipeline 6, the temperature of gasification furnace 5 is controlled, partial gasification reaction occurs between coal powder, oxygen and water vapor, and high-temperature fuel gas rich in CO is generated;Finally, high-temperature fuel gas carries unburned superfine coal powder and sprays into the hearth of boiler 1 through mixing assembly 2, to complete stable coal powder combustion in boiler 1.
[0025] Through the mixing pipe, on the one hand, high-temperature fuel gas carrying unburned superfine coal powder and air passing through can be fully introduced into boiler 1, so as to fully burn coal powder, and on the other hand, high-temperature fuel gas carrying unburned superfine coal powder can be buffered to slow down the impact on the inner wall of boiler 1.
[0026] In other preferred embodiments, the gasification furnace 5 is provided with a combination chamber at the top, the fourth pipeline 7 and the third pipeline 6 are arranged on the combination chamber, and the air inlet direction of the fourth pipeline 7 is perpendicular to the air inlet direction of the third pipeline 6. The ultrafine coal powder and the mixed gas are preliminarily combined through the combination chamber, and then the ultrafine coal powder is ignited by using a high-energy igniter, so as to ensure the uniformity of the reaction.
[0027] In other preferred embodiments, the outer tube comprises a transition chamber 21 and a combination chamber, the inner diameter of the transition chamber 21 gradually increases from one side of the first pipeline 3 to the other side, and the guide block 22 adjacent to one side of the first pipeline 3 is in a circular table structure, and the circular table side of the guide block 22 is arranged in the transition chamber 21. The high-temperature combustion gas is diffused from the center to the periphery by the guide block 22, and is fully combined with the gas led out of the second pipeline 4.
[0028] In other preferred embodiments, the fifth pipeline 9 is arranged on the coal mill 8, the fifth pipeline 9 is used for introducing air, the fifth pipeline 9 is provided with a filter chamber 93, the filter chamber 93 is provided with a mounting hole, the mounting hole is detachably provided with a mounting frame 91, and the mounting frame 91 is fixedly connected with a filter plate 92. The filter plate 92 can remove impurities from the entering air, so as to avoid dust from entering the inside of the coal mill 8 and affecting the quality of the coal powder.
[0029] In other preferred embodiments, the hole channel of the air outlet hole 24 is obliquely arranged, and the oblique direction of the hole channel is opposite to the air inlet direction of the first pipeline 3. Through the arrangement of the structure, the gas can flow in opposite directions, which can increase the combination effect and also provide a buffer for the high-temperature combustion gas in the first pipeline 3.
[0030] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.
Claims
1. A low load combustion device for a coal-fired unit, characterized by, The utility model relates to a coal gasification system, including coal mill, gasification furnace and boiler arranged in sequence, the coal mill is connected with gasification furnace through the fourth pipeline, the gasification furnace is connected with mixed component through the first pipeline, the mixed component is fixedly connected on the boiler and is communicated with the inside of boiler, still be provided with the second pipeline on the mixed component, the mixed component includes outer tube, the transition cavity and the combination cavity are included in the inside of outer tube, the inside diameter of transition cavity gradually increases from one side of the first pipeline to the other side, the side of the transition cavity is provided with the air outlet hole.
2. The low load combustion device for coal-fired units according to claim 1, characterized in that, The utility model relates to a coal gasification system, including coal mill, gasification furnace and boiler arranged in sequence, the coal mill is connected with gasification furnace through the fourth pipeline, the gasification furnace is connected with mixed component through the first pipeline, the mixed component is fixedly connected on the boiler and is communicated with the inside of boiler, still be provided with the second pipeline on the mixed component, the mixed component includes outer tube, the transition cavity and the combination cavity are included in the inside of outer tube, the inside diameter of transition cavity gradually increases from one side of the first pipeline to the other side, the side of the transition cavity is provided with the air outlet hole.
3. The low load combustion device for coal-fired units according to claim 1, characterized in that, The utility model relates to a coal gasification system, including coal mill, gasification furnace and boiler arranged in sequence, the coal mill is connected with gasification furnace through the fourth pipeline, the gasification furnace is connected with mixed component through the first pipeline, the mixed component is fixedly connected on the boiler and is communicated with the inside of boiler, still be provided with the second pipeline on the mixed component, the mixed component includes outer tube, the transition cavity and the combination cavity are included in the inside of outer tube, the inside diameter of transition cavity gradually increases from one side of the first pipeline to the other side, the side of the transition cavity is provided with the air outlet hole.
4. The low load combustion device of a coal-fired unit according to claim 1, characterized in that, The utility model relates to a coal gasification system, including coal mill, gasification furnace and boiler arranged in sequence, the coal mill is connected with gasification furnace through the fourth pipeline, the gasification furnace is connected with mixed component through the first pipeline, the mixed component is fixedly connected on the boiler and is communicated with the inside of boiler, still be provided with the second pipeline on the mixed component, the mixed component includes outer tube, the transition cavity and the combination cavity are included in the inside of outer tube, the inside diameter of transition cavity gradually increases from one side of the first pipeline to the other side, the side of the transition cavity is provided with the air outlet hole.
5. The low load combustion device of a coal-fired unit according to claim 1, characterized in that, The utility model relates to a coal gasification system, including coal mill, gasification furnace and boiler arranged in sequence, the coal mill is connected with gasification furnace through the fourth pipeline, the gasification furnace is connected with mixed component through the first pipeline, the mixed component is fixedly connected on the boiler and is communicated with the inside of boiler, still be provided with the second pipeline on the mixed component, the mixed component includes outer tube, the transition cavity and the combination cavity are included in the inside of outer tube, the inside diameter of transition cavity gradually increases from one side of the first pipeline to the other side, the side of the transition cavity is provided with the air outlet hole.