Full-load self-adapting ultra-low-load stable combustion fast ramping pulverized coal burner

Abstract

This application discloses a full-load adaptive ultra-low load stable combustion and rapid ramp-climbing pulverized coal burner, comprising: a primary air duct, a pulverized coal concentrator, a multi-stage pyrolysis combustion chamber, an ignition system, an oxygen supply system, a gas film cooling system, an energy storage pulverized coal silo, and an intelligent control system; the multi-stage pyrolysis combustion chamber is composed of a primary pyrolysis chamber, a secondary combustion chamber, and a tertiary stable combustion chamber connected in series; the primary pyrolysis chamber is equipped with a porous medium heat storage body, utilizing its high heat storage characteristics to achieve heat feedback stable combustion; the secondary combustion chamber has spiral cooling air grooves on its inner wall to form a rotating wall-mounted cooling gas film to prevent coking; the tertiary stable combustion chamber outlet is equipped with an adjustable flaming ring; the energy storage pulverized coal silo stores high-concentration pulverized coal, enabling instantaneous pulverized coal supply and rapid ramp-climbing. This invention can achieve stable combustion at 0% load and ultra-low load, with a load change rate of 5%-10% / minute, fuel consumption of only 3-8 kg / h, and can burn low-quality fuels such as anthracite and coal gangue, improving combustion rate and ramp-climbing ability.

Description

Technical Field

[0001] This invention relates to the field of coal-fired boiler combustion technology, specifically to a full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner. Background Technology

[0002] With the continuous increase in the proportion of renewable energy power generation, coal-fired power units are transitioning from baseload power sources to regulating power sources, placing stringent demands on the deep peak-shaving capabilities of these units. Existing pulverized coal burners have the following technical deficiencies under low-load conditions:

[0003] Stable combustion at ultra-low loads is difficult. The minimum stable combustion load for traditional burners is usually 30%-40% of the rated load. Further reduction of the load can easily cause flameout. Although pre-combustion chamber burners can achieve stable combustion at about 20% load, high-temperature molten particles can easily scour the wall surface, causing serious coking and burn-off.

[0004] The load response speed is slow. Due to the delay in warming up the grinding system, the load change rate is only 1%-2% / minute, which cannot meet the grid's rapid frequency regulation requirements.

[0005] It has poor adaptability to different types of coal and insufficient ability to ignite low-volatile anthracite and low-calorific-value coal gangue, which limits the utilization of solid waste resources.

[0006] Gas film cooling technology has not yet been applied to pulverized coal burners, making it difficult to fundamentally solve the problem of coking and burning loss during low-load stable combustion from a structural perspective. Summary of the Invention

[0007] The purpose of this invention is to propose a full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner to solve the problems mentioned in the background art.

[0008] To achieve the above-mentioned objectives, the first technical solution adopted by the present invention is: a full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner, comprising: a primary air duct, a pulverized coal concentrator, a multi-stage pyrolysis combustion chamber, an ignition system, an oxygen supply system, and an intelligent control system; The multi-stage pyrolysis combustion chamber includes a primary pyrolysis chamber, a secondary combustion chamber, and a tertiary combustion stabilization chamber, with each stage of the combustion chamber connected in series via a high-temperature resistant constriction. The primary pyrolysis chamber is equipped with a porous medium heat storage body to store high-temperature heat and radiate preheating coal powder airflow. The inner wall of the secondary combustion chamber is provided with a spiral cooling air groove, which is connected to the air film cooling system to form a rotating wall-adhering cooling air film on the inner wall of the combustion chamber. An adjustable flare-stabilizing ring is installed at the outlet of the third-stage combustion chamber; The burner is connected to an independent pulverized coal storage bin, which is used to store high-concentration pulverized coal at ultra-low loads to achieve instantaneous fuel supply during rapid ramp-up.

[0009] Furthermore, the ignition system is a composite micro-oil ignition gun with a fuel capacity of 3-8 kg / h, and the oxygen supply system includes an oxygen supply pipe. The composite micro-oil ignition gun and the oxygen supply pipe are located in the primary pyrolysis chamber.

[0010] Furthermore, the porous medium heat storage body is made of silicon carbide foam ceramic material with a porosity of 80%-90% and a thickness of 50-120mm. The front end of the porous medium heat storage body is 30-50mm away from the nozzle of the composite micro-oil ignition gun.

[0011] Furthermore, the spiral cooling air trough has a spiral angle of 30°-60°, a trough depth of 3-8mm, a trough width of 5-10mm, and a trough spacing of 10-20mm; the cooling air volume accounts for 3%-10% of the total primary air volume.

[0012] Furthermore, the adjustable flare stabilizer ring is driven by a shape memory alloy and automatically adjusts the expansion angle according to the burner wall temperature, with an adjustment range of 15°-45°.

[0013] Furthermore, the energy storage coal powder silo is connected to the burner via a pneumatic conveying pipeline, and the pneumatic conveying pipeline is equipped with a quick-opening valve with a response time of ≤2 seconds; the coal powder concentration stored in the energy storage coal powder silo is 0.8-1.2 kg coal / kg air.

[0014] Furthermore, the intelligent control system includes a load prediction module, an energy storage management module, an air film cooling control module, and a porous media regeneration module.

[0015] Furthermore, the load forecasting module predicts load change trends 30-60 seconds in advance based on grid dispatch instructions and real-time unit load.

[0016] Due to the application of the above-mentioned technical solution, the present invention has the following advantages compared with the prior art: 1. Breakthrough ultra-low load stable combustion: The minimum stable combustion load is reduced to 0% (only power supply to the plant), achieving a qualitative leap compared to existing technologies (20%-30%). The porous medium heat storage body utilizes its high specific surface area and strong radiation characteristics to rapidly store heat during micro-oil ignition. After successful ignition, it continuously radiates heat to the pulverized coal gas flow, achieving "thermal feedback" stable combustion.

[0017] 2. Revolutionary rapid ramp-up capability: Variable load rate reaches 5%-10% / minute, 5-10 times faster than traditional units. The energy storage pulverized coal silo technology solves the industry problem of response delay in pulverizing systems, with a fast-opening valve response time ≤2 seconds.

[0018] 3. Wide adaptability to various coal types: It can burn anthracite with volatile matter ≥5%, coal gangue and coal slime with calorific value ≥1200kcal / kg, realizing the resource utilization of low-calorific-value and low-quality fuels.

[0019] 4. Innovative film cooling technology: The film cooling technology of aero-engine combustion chambers is innovatively applied to pulverized coal burners. A rotating, wall-attached film is formed through spiral cooling air channels, and the wall temperature is controlled at ≤550℃, which completely solves the problem of coking and burning loss during low-load stable combustion.

[0020] 5. Intelligent adaptive control: Based on load prediction, energy storage management and film cooling control enable adaptive operation under all operating conditions, reducing the workload of operators. Attached Figure Description

[0021] Figure 1 The diagram shows the structure of the full-load adaptive ultra-low load stable combustion and rapid ramp pulverized coal burner provided in the embodiment of the present invention.

[0022] In the diagram: 1. Primary air duct, 2. Pulverized coal concentrator, 3. Multi-stage pyrolysis combustion chamber, 4. Ignition system, 5. Gas film cooling system, 6. Energy storage pulverized coal silo, 7. Adjustable flared flame stabilizer ring. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or system that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or systems.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] like Figure 1As shown, this embodiment of the invention provides a full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner, including: a primary air duct 1, a pulverized coal concentrator 2, a multi-stage pyrolysis combustion chamber 3, an ignition system 4, an oxygen supply system, and an intelligent control system. The coal pulverizer 2 is connected to one end of the multi-stage pyrolysis combustion chamber 3, and the primary air duct 1 is connected to one end of the coal pulverizer 2. The multi-stage pyrolysis combustion chamber 3 includes a first-stage pyrolysis chamber, a second-stage combustion chamber and a third-stage stable combustion chamber. The combustion chambers at each stage are connected in series through a high-temperature resistant constriction. A porous medium heat storage body is installed in the primary pyrolysis chamber to store high-temperature heat and radiate preheating coal powder gas flow. Spiral cooling air channels are provided on the inner wall of the secondary combustion chamber. The spiral cooling air channels are connected to the air film cooling system 5 to form a rotating wall-mounted cooling air film on the inner wall of the combustion chamber. An adjustable flare stabilizing ring 7 is installed at the outlet of the third-stage combustion chamber; The burner is connected to an independent pulverized coal storage bin 6, which is used to store high-concentration pulverized coal at ultra-low loads to achieve instantaneous fuel supply during rapid ramp-up.

[0027] According to an embodiment of the present invention, the ignition system 4 is a composite micro-oil ignition gun with a fuel quantity of 3-8 kg / h, and the oxygen supply system includes an oxygen supply pipe. The composite micro-oil ignition gun and the oxygen supply pipe are arranged in the primary pyrolysis chamber.

[0028] According to an embodiment of the present invention, the porous medium heat storage body is made of silicon carbide foam ceramic material with a porosity of 80%-90% and a thickness of 50-120mm. The front end face of the porous medium heat storage body is 30-50mm away from the nozzle of the composite micro-oil ignition gun.

[0029] According to an embodiment of the present invention, the spiral cooling air duct has a spiral angle of 30°-60°, a duct depth of 3-8mm, a duct width of 5-10mm, and a duct spacing of 10-20mm; the cooling air volume accounts for 3%-10% of the total primary air volume.

[0030] According to an embodiment of the present invention, the adjustable flare stabilizer ring 7 is driven by a shape memory alloy and automatically adjusts the expansion angle according to the burner wall temperature, with an adjustment range of 15°-45°.

[0031] According to an embodiment of the present invention, the energy storage coal powder silo 6 is connected to the burner through a pneumatic conveying pipeline, and the pneumatic conveying pipeline is equipped with a quick-opening valve with a response time of ≤2 seconds; the energy storage coal powder silo 6 stores coal powder with a concentration of 0.8-1.2 kg coal / kg air.

[0032] According to an embodiment of the present invention, the intelligent control system includes a load prediction module, an energy storage management module, an air film cooling control module, and a porous media regeneration module.

[0033] According to an embodiment of the present invention, the load forecasting module predicts the load change trend information 30-60 seconds in advance based on the grid dispatching instructions and the real-time load of the generating units.

[0034] In summary, the present invention has the following advantages compared with the prior art: 1. Breakthrough ultra-low load stable combustion: The minimum stable combustion load is reduced to 0% (only power supply to the plant), achieving a qualitative leap compared to existing technologies (20%-30%). The porous medium heat storage body utilizes its high specific surface area and strong radiation characteristics to rapidly store heat during micro-oil ignition. After successful ignition, it continuously radiates heat to the pulverized coal gas flow, achieving "thermal feedback" stable combustion.

[0035] 2. Revolutionary rapid ramp-up capability: Variable load rate reaches 5%-10% / minute, 5-10 times faster than traditional units. The energy storage pulverized coal silo technology solves the industry problem of response delay in pulverizing systems, with a fast-opening valve response time ≤2 seconds.

[0036] 3. Wide adaptability to various coal types: It can burn anthracite with volatile matter ≥5%, coal gangue and coal slime with calorific value ≥1200kcal / kg, realizing the resource utilization of low-calorific-value and low-quality fuels.

[0037] 4. Innovative film cooling technology: The film cooling technology of aero-engine combustion chambers is innovatively applied to pulverized coal burners. A rotating, wall-attached film is formed through spiral cooling air channels, and the wall temperature is controlled at ≤550℃, which completely solves the problem of coking and burning loss during low-load stable combustion.

[0038] 5. Intelligent adaptive control: Based on load prediction, energy storage management and film cooling control enable adaptive operation under all operating conditions, reducing the workload of operators.

[0039] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A full load adaptive ultra-low load stable combustion fast ramping pulverized coal burner, comprising: The system comprises a primary air duct, a pulverized coal concentrator, a multi-stage pyrolysis combustion chamber, an ignition system, an oxygen supply system, and an intelligent control system, characterized in that: The multi-stage pyrolysis combustion chamber includes a primary pyrolysis chamber, a secondary combustion chamber, and a tertiary combustion stabilization chamber, with each stage of the combustion chamber connected in series via a high-temperature resistant constriction. The primary pyrolysis chamber is equipped with a porous medium heat storage body to store high-temperature heat and radiate preheating coal powder airflow. The inner wall of the secondary combustion chamber is provided with a spiral cooling air groove, which is connected to the air film cooling system to form a rotating wall-adhering cooling air film on the inner wall of the combustion chamber. An adjustable flare-stabilizing ring is installed at the outlet of the third-stage combustion chamber; The burner is connected to an independent pulverized coal storage bin, which is used to store high-concentration pulverized coal at ultra-low loads to achieve instantaneous fuel supply during rapid ramp-up.

2. The full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner as described in claim 1, characterized in that, The ignition system is a composite micro-oil ignition gun with a fuel capacity of 3-8 kg / h. The oxygen supply system includes an oxygen supply pipe, and the composite micro-oil ignition gun and the oxygen supply pipe are located in the primary pyrolysis chamber.

3. The full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner as described in claim 2, characterized in that, The porous medium heat storage body is made of silicon carbide foam ceramic material with a porosity of 80%-90% and a thickness of 50-120mm. The front end of the porous medium heat storage body is 30-50mm away from the nozzle of the composite micro-oil ignition gun.

4. The full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner as described in claim 3, characterized in that, The spiral cooling air duct has a spiral angle of 30°-60°, a duct depth of 3-8mm, a duct width of 5-10mm, and a duct spacing of 10-20mm; the cooling air volume accounts for 3%-10% of the total primary air volume.

5. The full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner as described in claim 1, characterized in that, The adjustable flare stabilizer ring is driven by a shape memory alloy and automatically adjusts the expansion angle according to the burner wall temperature, with an adjustment range of 15°-45°.

6. The full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner as described in claim 1, characterized in that, The energy storage coal powder silo is connected to the burner via a pneumatic conveying pipeline. The pneumatic conveying pipeline is equipped with a quick-opening valve with a response time of ≤2 seconds. The coal powder concentration stored in the energy storage coal powder silo is 0.8-1.2 kg coal / kg air.

7. The full-load adaptive ultra-low load stable combustion and rapid ramp-up pulverized coal burner as described in claim 1, characterized in that, The intelligent control system includes a load prediction module, an energy storage management module, an air film cooling control module, and a porous media regeneration module.

8. The full-load adaptive ultra-low load stable combustion and rapid ramp-climbing pulverized coal burner as described in claim 7, characterized in that, The load forecasting module predicts load change trends 30-60 seconds in advance based on grid dispatch instructions and real-time unit load.

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