W furnace pulverized coal combustion heat source input device

Abstract

The application discloses a W furnace pulverized coal combustion heat source input device and belongs to the field of boiler combustion equipment. The device comprises an eccentric reducer, a pulverized coal concentration distribution device, a primary combustion chamber, an input heat source device, a multi-stage combustion chamber, a final mixing chamber and a combustion auxiliary air passage. The wind-pulverized coal mixture is accelerated into the pulverized coal concentration distribution device through the eccentric reducer and is separated into low-concentration wind-pulverized coal mixture and high-concentration wind-pulverized coal mixture. The low-concentration wind-pulverized coal mixture is directly sent into the W furnace hearth, and the high-concentration wind-pulverized coal mixture is ignited in the primary combustion chamber through the input heat source, is mixed and combusted with another high-concentration wind-pulverized coal and auxiliary air in the multi-stage combustion chamber, and is finally sent into the W furnace hearth in a uniform manner through the final mixing chamber, so that most of the pulverized coal reaches a pre-combustion state before entering the furnace hearth. The device can significantly improve the ignition stability of low-volatile pulverized coal under low load and avoid extinguishing.

Description

Technical Field

[0001] This invention belongs to the technical field of boiler combustion equipment, specifically relating to a W-type pulverized coal combustion heat source input device. Background Technology

[0002] With the emergence of deep peak shaving and spot trading operations in China, "W"-type flame boilers (W-type boilers) are prone to flameout under deep peak shaving conditions, making it difficult to meet safe operation requirements. W-type boilers typically burn anthracite or lean coal, which has low volatile matter content, high ignition temperature, and is extremely difficult to ignite. Under high load conditions, the furnace temperature is high, allowing pulverized coal to achieve self-sustaining combustion; however, under low load conditions, the furnace temperature drops significantly, making it difficult to achieve the heat required for initial ignition of such coal, easily leading to incomplete combustion of pulverized coal within the furnace and subsequent unit flameout. Therefore, a measure is needed to initially ignite such coal to avoid the problem of pulverized coal failing to burn in the furnace and forcing unit shutdown.

[0003] In existing technologies, methods to improve the ignition stability of low-volatile pulverized coal include increasing the temperature of the primary air-coal mixture, adding auxiliary fuel oil or gas ignition guns, and optimizing the burner structure. However, these methods have limitations under deep peak-shaving conditions. Increasing the primary air temperature is limited by the upper limit of hot air temperature and the safety of the pulverizing system, resulting in a limited adjustment range. Furthermore, when the furnace temperature is too low, even increasing the air temperature may not be enough to meet the heat absorption required for ignition. While adding an auxiliary fuel ignition device can provide localized high temperatures, the consumption of auxiliary fuel is high under extremely low loads, leading to poor economic efficiency. Moreover, the flame stability of the ignition device itself is affected by the furnace negative pressure and low-temperature environment, posing a risk of flameout. Optimizing the burner structure (such as changing the nozzle angle or adding stabilizing teeth) has limited effect on improving the quality of extremely low-volatile coal and cannot fundamentally solve the problem of difficult ignition at low furnace temperatures.

[0004] Furthermore, the W-shaped flame of the W-type furnace has a relatively long travel distance, resulting in a longer residence time of pulverized coal within the furnace. However, under low furnace temperatures, the pulverized coal flow may extinguish due to excessive heat loss before reaching the ignition temperature. In actual operation, it has also been found that simply adjusting the secondary air distribution or changing the pulverizer configuration is insufficient to maintain a stable flame center under deep peak-shaving conditions. Attempts have been made to introduce external high-temperature heat sources (such as plasma igniters or small oil guns) directly onto the primary air-coal mixture. However, due to uneven mixing of the heat source and the pulverized coal flow, and the short duration of the heat source's effect, only a localized portion of the pulverized coal is often ignited. The ignited pulverized coal is prone to extinguishing again due to the low ambient temperature before entering the main combustion zone of the furnace. Increasing the external heat source continuously would lead to fuel waste and burner overheating. How to provide a reliable and economical external heat source for the W-type furnace to ignite low-volatile pulverized coal over a wide load range, especially under deep peak-shaving low-load conditions, while avoiding excessive reliance on auxiliary fuels and insufficient heat source coverage or energy waste, remains a long-standing technical challenge for those skilled in the art. Existing methods of introducing a single heat source (such as simply adding an ignition gun or plasma generator) suffer from several problems, including inflexible heat source intensity adjustment, poor mixing with pulverized coal, and the inability of the heat source to continuously act on subsequent pulverized coal. These issues make it difficult to ensure that the pulverized coal reaches a stable, self-sustaining combustion state before entering the main combustion zone of the furnace. Summary of the Invention

[0005] This invention provides a W-type pulverized coal combustion heat source input device, which can concentrate the air-coal mixture in stages through a pulverized coal concentration distribution device, and use the input heat source device to ignite the high-concentration pulverized coal in stages. In conjunction with a flame status feedback device and a remote intelligent control system, it dynamically adjusts the separation ratio, heat source supply and auxiliary air velocity, thereby achieving stable ignition of low-volatile pulverized coal under deep peak shaving and low load conditions, reducing auxiliary fuel consumption and avoiding boiler flameout.

[0006] To achieve these objectives and other advantages of the present invention, the present invention provides a W-type pulverized coal combustion heat source input device, comprising: An eccentric reducer, the inlet of which is used to receive the air-coal mixture output from the air-coal system; A pulverized coal concentration distribution device, the inlet of which is connected to the outlet of the eccentric reducer, the pulverized coal concentration distribution device having a high-concentration air-coal mixture outlet and a low-concentration air-coal mixture outlet, the low-concentration air-coal mixture outlet being used to connect to the furnace of the W furnace; A primary combustion chamber has a primary chamber first inlet, a primary chamber second inlet, and a primary chamber outlet, wherein the primary chamber first inlet is connected to the high-concentration air-coal mixture outlet of the pulverized coal concentration distribution device; An input heat source device is provided, the output of which is connected to the second inlet of the primary chamber, for providing a high-temperature heat source to the primary combustion chamber. A multi-stage combustion chamber has a first inlet, a second inlet, a third inlet, and an outlet. The first inlet is connected to the outlet of the primary chamber, and the second inlet is connected to the outlet of the high-concentration air-coal mixture of the pulverized coal concentration distribution device. The final mixing chamber has a mixing chamber inlet and a mixing chamber outlet, the mixing chamber inlet being connected to the multi-stage chamber outlet and the mixing chamber outlet being connected to the furnace of the W furnace; The combustion auxiliary air duct has its outlet connected to the third inlet of the multi-stage chamber.

[0007] Preferably, the pulverized coal concentration distribution device is a centrifugal separator with adjustable distribution blades inside. The air-powder mixture accelerated by the eccentric reducer enters the pulverized coal concentration distribution device, whereby the pulverized coal is separated along the directional flow direction of the adjustable distribution blades under centrifugal force. The pulverized coal concentration distribution device separates 50% of the total air and 10%-15% of the total pulverized coal in the air-powder mixture into the low-concentration air-powder mixture, and separates the remaining 50% of the air and 85%-90% of the pulverized coal into the high-concentration air-powder mixture.

[0008] Preferably, it also includes a flame status feedback device, which includes: a photosensitive signal sensor, an infrared sensor, and a temperature sensor; at least one of the photosensitive signal sensors and at least one of the infrared sensors are respectively installed inside the primary combustion chamber, the multi-stage combustion chamber, or the final mixing chamber to collect flame light intensity signals and flame infrared radiation signals; at least one temperature sensor is respectively installed inside the primary combustion chamber, the multi-stage combustion chamber, the final mixing chamber, or the furnace chamber of the W furnace to collect temperature signals; It also includes a pulverized coal concentration sensor, which is installed at the inlet of the pulverized coal concentration distribution device or on the flow pipe of the high-concentration air-coal mixture, for collecting pulverized coal concentration signals; The flame status feedback device and the pulverized coal concentration sensor output the collected signals to the remote intelligent control system.

[0009] Preferably, the pulverized coal concentration distribution device is equipped with a remote control mechanism; the remote control mechanism and the boiler control system are respectively communicatively connected to the remote intelligent control system; The remote intelligent control system reads the unit operating load signal and coal quality characteristics data from the boiler control system, and generates control commands based on the read data and the signals collected by the flame status feedback device, and sends them to the remote control mechanism; the remote control mechanism controls the adjustable distribution blades to change their deflection angle according to the received control commands, so as to dynamically adjust the distribution ratio of the high-concentration air-coal mixture and the low-concentration air-coal mixture. The remote intelligent control system is configured to: when the signal collected by the flame status feedback device indicates that the combustion is unstable, the remote control mechanism is activated first to adjust the deflection angle of the adjustable distribution blades, so as to maintain stable combustion by increasing the coal powder concentration. Under low-load conditions, the coal powder concentration of the high-concentration air-coal mixture is adjusted to 0.85-1.0 kg coal powder / kg air, and the coal powder fineness R90 ≤ 6%.

[0010] Preferably, the input heat source device includes an input heat source main chemical agent inlet, an input heat source auxiliary chemical agent inlet, and an input heat source enhancing reactant inlet; the input heat source main chemical agent is at least one of hydrogen, natural gas, ammonia, Brown gas, or fuel oil, used to provide initial ignition energy; the input heat source auxiliary chemical agent is air, oxygen, or compressed air, used to physically disperse the input heat source main chemical agent and provide initial reaction conditions; the input heat source enhancing reactant is air, oxygen, or compressed air, used to enhance the reaction intensity of the input heat source main chemical agent and prevent nozzle burn-out.

[0011] Preferably, the remote intelligent control system is also communicatively connected to the chemical inlet valves of the input heat source device and the wind speed regulating device of the combustion auxiliary air; the remote intelligent control system automatically adjusts the input heat source supply, the coal powder separation ratio and the wind speed of the combustion auxiliary air according to the real-time monitored temperature, coal powder concentration and flame intensity of the primary combustion chamber, the multi-stage combustion chamber and the final mixing chamber, so as to achieve on-demand supply.

[0012] Preferably, the multi-stage combustion chamber is provided with a staged adjustment device on its exterior. The staged adjustment device includes at least one set of rotatable baffles. The baffles extend into the interior of the multi-stage combustion chamber, and each baffle is rotatably arranged around its own rotation axis, which is perpendicular to the axis of the multi-stage combustion chamber. The deflection angle of the baffles is adjustable in the range of 0° to 60°. By changing the deflection angle, the projected area of ​​the baffles in the airflow direction is adjusted, thereby selectively blocking or opening part of the combustion passage of the multi-stage combustion chamber and applying a turbulence effect to the internal airflow.

[0013] Preferably, the combustion auxiliary air duct is located on the periphery of the multi-stage combustion chamber, and the wind speed and volume of the combustion auxiliary air are controlled independently of the high-concentration air-coal mixture; the combustion auxiliary air forms an air-coil flame structure on the outside of the multi-stage combustion chamber to provide air support for the complete combustion of pulverized coal in the W furnace.

[0014] Preferably, the output end of the input heat source device extends into the interior of the primary combustion chamber in a downward direction.

[0015] Preferably, the amount of the main chemical agent used in the input heat source is controlled by gradually increasing the amount in stages at proportions of 20%, 40%, 60%, 80%, and 100%.

[0016] The present invention has at least the following beneficial effects: First, the device of this invention, through the combination of an eccentric reducer, a pulverized coal concentration distribution device, a primary combustion chamber, an input heat source device, a multi-stage combustion chamber, a final mixing chamber, and combustion auxiliary air, achieves the following: the air-pulverized coal mixture is first concentrated and separated, and then the high-concentration portion is mixed and burned with the input heat source multiple times, progressively increasing the temperature of the pulverized coal, so that most of the pulverized coal reaches a preliminary pre-combustion state before entering the W-type furnace. This structure effectively solves the problem of pulverized coal being difficult to ignite under low furnace temperature conditions, avoids unit flameout caused by the inability of pulverized coal to burn in the furnace, and improves the operational reliability of the W-type furnace under deep peak-shaving conditions. Simultaneously, the multi-stage combustion chamber design allows the heat source to continuously act on subsequent pulverized coal, overcoming the shortcomings of a single heat source, such as short action time and uneven mixing.

[0017] Secondly, by employing a centrifugal separator with adjustable distribution blades inside, combined with the accelerating effect of an eccentric reducer, this device can efficiently separate pulverized coal from the air-coal mixture at a specific ratio (85%-90% concentrated on the high-concentration side), significantly increasing the pulverized coal concentration in the high-concentration air-coal mixture. The high concentration of pulverized coal reduces the external heat absorption required for ignition, making it easier to ignite at the same furnace temperature. Simultaneously, the low-concentration air-coal mixture (containing 10%-15% pulverized coal) is directly fed into the furnace, avoiding energy waste. The adjustable distribution blades provide the structural basis for subsequent dynamic adjustment of the separation ratio, enabling the device to adapt to different operating conditions.

[0018] Third, by installing photosensitive signal sensors, infrared sensors, and temperature sensors in the primary combustion chamber, multi-stage combustion chamber, final mixing chamber, and W-furnace, as well as a pulverized coal concentration sensor at the inlet of the pulverized coal concentration distribution device or on the high-concentration pipeline, this device can collect multi-parameter signals such as flame intensity, infrared radiation, temperature, and pulverized coal concentration in real time. These signals are output to the remote intelligent control system, providing data support for accurate judgment of the combustion state. Compared with traditional methods that rely solely on manual observation or single-parameter monitoring, this device achieves comprehensive perception of the combustion process, enabling timely detection of early signs of combustion instability and providing a reliable basis for subsequent automatic adjustments.

[0019] Fourth, by configuring a remote control mechanism for the pulverized coal concentration distribution device and communicating with the remote intelligent control system and boiler control system, this device can dynamically adjust the deflection angle of the adjustable distribution blades according to the unit's operating load, the characteristics of the coal used, and the flame status feedback signal, thereby changing the distribution ratio of the high- and low-concentration air-coal mixture. Specifically, when combustion instability is detected, the system prioritizes maintaining stable combustion by increasing the pulverized coal concentration, rather than immediately increasing the input of an external heat source, thus reducing auxiliary fuel consumption. Under low-load conditions, the high-concentration side pulverized coal concentration can be adjusted to 0.85-1.0 kg pulverized coal / kg air with a pulverized coal fineness R90 ≤ 6%. This parameter range has been verified to reduce the ignition temperature and achieve stable combustion under low load.

[0020] Fifth, by setting the input heat source device to three independent inlets (main chemical agent, auxiliary chemical agent, and enhancing reactant), this device can flexibly adjust the intensity, dispersion, and reaction intensity of the heat source. The main chemical agent provides initial ignition energy and can use various fuels such as hydrogen and natural gas; the auxiliary chemical agent (air, oxygen, or compressed air) physically disperses the main chemical agent, avoiding local overheating and providing the oxidant required for the initial reaction; the enhancing reactant further intensifies the reaction and, by increasing the flow rate, cools the nozzles to prevent burn-out. This three-agent separation structure allows the heat source device to output both a gentle diffusion flame and a strong high-temperature jet, adapting to the ignition requirements of different coal qualities and operating conditions. By communicating with the remote intelligent control system and the inlet valves of each chemical agent and the wind speed adjustment device of the combustion auxiliary air of the input heat source device, this device can automatically adjust the input heat source supply, coal powder separation ratio, and combustion auxiliary air speed based on the real-time monitored temperature, coal powder concentration, and flame intensity of the primary combustion chamber, multi-stage combustion chamber, and final mixing chamber. This three-parameter linkage feedback control mechanism achieves "on-demand supply": when combustion is stable, the heat source input is reduced to save energy; when the pulverized coal concentration is low, the separation ratio is adjusted first; and when the flame intensity is insufficient, the heat source intensity is increased. Compared with manual or independent adjustment, this device significantly improves the accuracy and energy efficiency of combustion control and avoids excessive consumption of auxiliary fuel.

[0021] Sixth, by installing a staged adjustment device with rotatable baffle blades on the outside of the multi-stage combustion chamber, and with the deflection angle of the baffle blades adjustable within the range of 0° to 60°, this device can selectively shield or open some combustion channels of the multi-stage combustion chamber according to load requirements. At low loads, the blade deflection angle can be increased to shield some channels, reducing heat dissipation area and heat loss, and concentrating heat to maintain the core flame; at high loads, the blades can be reduced or brought to zero to open all channels, reducing flow resistance. Simultaneously, the baffle blades exert a turbulent effect on the internal airflow, enhancing the mixing of pulverized coal and high-temperature flue gas, and promoting the combustion reaction. This structure achieves staged combustion and rational energy utilization, improving the device's adaptability to variable load conditions.

[0022] Seventh, by controlling the amount of main chemical agent used in the input heat source in stages of 20%, 40%, 60%, 80%, and 100%, this device avoids the energy waste and local overheating caused by traditional one-time full-volume input. In the initial ignition stage, 20% of the main chemical agent is initially added, working with auxiliary chemicals and enhancing reactants to form a small flame, igniting the high concentration of pulverized coal in the primary combustion chamber. Once the temperature in the primary combustion chamber rises and the flame stabilizes, the input ratio is gradually increased until it reaches 100%. This staged input method ensures the safety of the initial burner (preventing deflagration or backfire) while reducing the consumption of the main chemical agent, thus improving economic efficiency. Especially under deep peak-shaving conditions, the input stage can be flexibly selected according to the actual furnace temperature to achieve precise ignition.

[0023] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the W-furnace pulverized coal combustion heat source input device of the present invention; Figure 2 This is a schematic diagram of the primary combustion chamber and multi-stage combustion chamber in the W-type pulverized coal combustion heat source input device of the present invention; Figure 3 This is a schematic diagram of one side of the W-furnace pulverized coal combustion heat source input device of the present invention; Figure 4 This is a schematic diagram showing the relationship between the various control components in the W-type pulverized coal combustion heat source input device of the present invention. Detailed Implementation

[0025] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0026] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0027] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the reagents and materials mentioned are commercially available. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They 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, and therefore should not be construed as a limitation of this invention.

[0028] like Figures 1-4 As shown, the present invention provides a W-type pulverized coal combustion heat source input device, comprising: An eccentric reducer 16 has an inlet for receiving the air-coal mixture 4 output from the air-coal system; The pulverized coal concentration distribution device 5 has its inlet connected to the outlet of the eccentric reducer 16. The pulverized coal concentration distribution device 5 has a high-concentration air-coal mixture 2 outlet and a low-concentration air-coal mixture 6 outlet. The low-concentration air-coal mixture 6 outlet is used to connect to the furnace 3 of the W furnace. The primary combustion chamber 10 has a primary chamber first inlet, a primary chamber second inlet and a primary chamber outlet, wherein the primary chamber first inlet is connected to the outlet of the high-concentration air-coal mixture 2 of the pulverized coal concentration distribution device 5; An input heat source device 1 is provided, the output end of which is connected to the second inlet of the primary chamber, for providing a high-temperature heat source to the primary combustion chamber 10; wherein the output end of the input heat source device 1 extends into the interior of the primary combustion chamber 10 at an angle downward. The multi-stage combustion chamber 11 has a first inlet, a second inlet, a third inlet, and an outlet. The first inlet is connected to the outlet of the primary chamber, and the second inlet is connected to the outlet of the high-concentration air-coal mixture 2 of the pulverized coal concentration distribution device 5. The final mixing chamber 12 has a mixing chamber inlet and a mixing chamber outlet, the mixing chamber inlet being connected to the multi-stage chamber outlet and the mixing chamber outlet being connected to the furnace 3 of the W furnace; The combustion auxiliary air duct 7 has its outlet connected to the third inlet of the multi-stage chamber.

[0029] In the above technical solution, the air-coal mixture 4 from the air-coal system is first received through an eccentric reducer 16. The inlet and outlet centers of this eccentric reducer are not on the same axis; utilizing the abrupt change in its cross-sectional shape, it can accelerate and turbulent the incoming air-coal mixture, providing power for the subsequent separation process. The accelerated air-coal mixture enters a pulverized coal concentration distribution device 5. The main function of this pulverized coal concentration distribution device 5 is to separate the air-coal mixture into two paths: one is a high-concentration air-coal mixture 2, and the other is a low-concentration air-coal mixture 6. The low-concentration air-coal mixture 6 is designed to be directly fed into the furnace 3 of the W furnace for combustion.

[0030] The high-concentration air-coal mixture 2 obtained after separation is divided into two paths, each interacting with an input heat source. The first path of the high-concentration air-coal mixture 2 enters the primary combustion chamber 10. This primary combustion chamber 10 is equipped with an input heat source device 1, the output of which is connected to the primary combustion chamber 10 to provide a high-temperature heat source to the chamber. The output of the input heat source device 1 extends into the primary combustion chamber 10 at a downward angle. The term "downward angle" means that the nozzle or pipe of the input heat source device 1 is not inserted horizontally or vertically, but rather at a certain angle (e.g., 30° to 60°) to the horizontal plane and points downward into the primary combustion chamber 10. Inside the primary combustion chamber 10, the chemical agents (including main chemical agents, auxiliary chemical agents, etc.) supplied by the input heat source device 1 undergo initial mixing and combustion with a portion of the high-concentration air-coal mixture 2 that has entered the chamber. This combustion is not intended to completely burn the coal powder, but rather to act as an "ignition seed," using an external heat source to ignite this portion of high-concentration coal powder, transforming it into a stable and continuous high-temperature heat source capable of further igniting more coal powder. Then, the high-temperature flue gas already in combustion state output from the primary combustion chamber 10, along with the unburned high-concentration air-coal mixture 2, enters the multi-stage combustion chamber 11. Simultaneously, a second high-concentration air-coal mixture 2, separated by the pulverized coal concentration distribution device 5, is also directly introduced into the multi-stage combustion chamber 11. Specifically, the high-concentration mixture outlet is divided into two paths, connecting the primary combustion chamber and the multi-stage combustion chamber respectively. In this way, the high-temperature flame generated by the primary combustion chamber 10 and the fresh high-concentration air-coal mixture 2 undergo intense mixing and combustion reactions within the multi-stage combustion chamber 11, causing the flame to be progressively amplified and strengthened, ensuring that most of the pulverized coal is successfully ignited at this stage. Outside the multi-stage combustion chamber 11, a combustion auxiliary air channel 7 is also provided, forming a "wind-wrapped flame" structure around the flame within the multi-stage combustion chamber 11. This auxiliary air is typically controlled to be injected at a high speed, its function being to provide sufficient oxygen to the already ignited pulverized coal, supporting its continued combustion, and preparing for subsequent complete combustion in the furnace 3, without directly impacting the core flame and ensuring combustion stability.

[0031] Finally, the gas stream from the multi-stage combustion chamber 11, containing already burned high-temperature flue gas, burning coke, and unburned pulverized coal, enters the final mixing chamber 12. In this mixing chamber, the gas stream undergoes intense turbulent diffusion, homogenizing the temperature and concentration fields and ensuring that all combustibles are fully heated and reach a stable combustion state. The gas stream, after being processed by the final mixing chamber 12, is ultimately sent to the main furnace 3 of the W furnace through its outlet. At this point, what enters the furnace 3 is no longer the difficult-to-ignite raw pulverized coal, but a high-temperature flame product in a stable combustion or about-to-sustain combustion state, thus significantly reducing the risk of fire extinguishing within the furnace 3.

[0032] Compared to existing technologies, this new method significantly reduces the ignition difficulty of low-volatile coal powder under low-load conditions by using a coal powder concentration distribution device 5 to concentrate the air-coal mixture in stages, and by utilizing a multi-stage combustion chamber structure 11 to mix and ignite the external heat source with high-concentration coal powder in stages and segments. This "dense-phase staged ignition" method effectively solves the problem of traditional single heat sources igniting and then extinguishing due to short action time and uneven mixing with coal powder, significantly improving the ignition stability and combustion efficiency of coal powder airflow under low furnace temperature conditions. Secondly, through the stepped combustion organization of "primary combustion chamber - multi-stage combustion chamber - final mixing chamber," the energy of the external heat source is efficiently used to ignite a portion of the coal powder, and then the heat released from the combustion of this portion of coal powder is used to ignite more coal powder, forming an energy-amplified chain reaction. This design significantly reduces the continuous reliance on expensive auxiliary fuels (such as oil and natural gas). Even under extremely low load conditions like deep peak shaving, only a brief or small-dose external heat source is needed to maintain the stability of the entire combustion process, resulting in significant energy-saving and economic advantages. Furthermore, by guiding most of the pulverized coal (high-concentration side) through a multi-stage combustion process, while directly feeding a small portion (low-concentration side) into furnace 3, "quality-based distribution" of the air-coal mixture is achieved. The high-concentration portion is preferentially used to construct a stable and controllable "ignition torch," while the low-concentration portion is directly fed into the furnace as "base" fuel, avoiding energy waste. Meanwhile, the clever arrangement of the combustion auxiliary air forms a "wind-enveloping-flame" structure, which not only provides the necessary oxygen to the core combustion zone, but also isolates the low-temperature flue gas in furnace 3. This effectively prevents the newly ignited pulverized coal flame from extinguishing due to excessive heat loss before entering the main combustion zone of furnace 3. Thus, it significantly reduces the risk of boiler flameout throughout the entire wide load regulation range, especially under extreme conditions of deep peak shaving of the unit, and ensures the safe, stable and economical operation of the unit.

[0033] In another technical solution, the pulverized coal concentration distribution device 5 is a centrifugal separator with adjustable distribution blades inside. The air-powder mixture accelerated by the eccentric reducer enters the pulverized coal concentration distribution device 5, causing the pulverized coal to separate along the directional flow direction of the adjustable distribution blades under the action of centrifugal force. The pulverized coal concentration distribution device 5 separates 50% of the total air and 10%-15% of the total pulverized coal in the air-powder mixture into the low-concentration air-powder mixture 6, and separates the remaining 50% of the air and 85%-90% of the pulverized coal into the high-concentration air-powder mixture 2.

[0034] In the above technical solution, the specific type of the pulverized coal concentration distribution device 5 is defined as a centrifugal separator, and adjustable distribution blades are installed inside the device. The working principle of the centrifugal separator is to use the centrifugal force generated by the rotating airflow to throw larger pulverized coal particles toward the wall, while smaller air particles tend toward the center. The adjustable distribution blades act like a set of guide plates that can change angle, guiding the rotation intensity and direction of the airflow, thereby changing the efficiency of pulverized coal being thrown out. In actual implementation, the pulverized coal concentration distribution device 5 is usually designed as a volute or cyclone separator structure, with the adjustable distribution blades installed at the inlet or in the internal guide area. The deflection angle of the blades refers to the angle between the blade plane and the main airflow direction of the air-powder mixture (or the tangential direction of the separator shell). When the deflection angle is small, the blade plane is close to parallel to the airflow, the guiding effect on the airflow is weak, the airflow rotation intensity is low, and the separation effect is relatively mild. When the deflection angle increases, the blade's blocking and guiding effect on the airflow is enhanced, the airflow rotation is more violent, the centrifugal separation effect is more thorough, and more coal powder can be thrown to the high concentration side.

[0035] Before entering the pulverized coal concentration distribution device 5, the air-powder mixture is accelerated by an eccentric reducer. Because the inlet and outlet centers of the eccentric reducer are not on the same straight line, an asymmetrical contraction effect is generated, significantly increasing the airflow velocity and creating a certain swirling inertia, providing initial momentum for subsequent centrifugal separation. The accelerated air-powder mixture enters the pulverized coal concentration distribution device 5 tangentially or spirally. Under centrifugal force, the pulverized coal particles move along the directional flow trajectory set by the adjustable distribution blades. The denser pulverized coal is guided to the high-concentration outlet side, while the less dense air and extremely fine pulverized coal flow to the low-concentration outlet side. By adjusting the angle of the distribution blades, the degree of pulverized coal deflection can be controlled, thus achieving flexible adjustment of the separation ratio. This device separates approximately half of the total air volume (about 50%) and 10% to 15% of the total pulverized coal volume from the incoming air-powder mixture, forming a low-concentration air-powder mixture 6; the remaining approximately half of the air volume (about 50%) and 85% to 90% of the pulverized coal form a high-concentration air-powder mixture 2. It should be noted that 10%-15% is an optional reference range, which can be optimized according to the coal quality characteristics in actual operation. For example, for anthracite with extremely low volatile matter, 12% of the pulverized coal can be sent to the low-concentration side and 88% to the high-concentration side to further enhance ignition energy. For lean coal with slightly higher volatile matter, the proportion of low-concentration coal can be appropriately increased to about 14% to balance combustion efficiency. The optimal value is usually recommended to be 12% pulverized coal on the low-concentration side and 88% on the high-concentration side. This ensures that the high-concentration side has good ignition characteristics while preventing incomplete combustion of the low-concentration side in furnace 3 due to insufficient pulverized coal. It should be noted that the phrase "separating 50% of the total air volume in the coal powder mixture into a low-concentration coal powder mixture 6" does not mean that the coal powder concentration distribution device 5 can precisely separate air molecules in a 50%:50 ratio like a sieve. Rather, it means that by rationally designing the flow cross-sectional area of ​​the two outlets of the separation device and the resistance of the subsequent pipelines, the gas flow through the low-concentration outlet and the high-concentration outlet is approximately equal, each accounting for about half of the total air volume. In engineering practice, this ratio is allowed to fluctuate within a certain range (e.g., 45% to 55%), with 50% being an optimal design target value. The air volume distribution can be fine-tuned by adjusting the deflection angle of the distribution blades, but maintaining a basic balance between the two air volumes mainly relies on the optimized design of the outlet structure. Therefore, the "50% of the total air volume" should be understood as "approximately half of the total air volume," rather than an absolutely precise 50%.

[0036] Compared to traditional pulverized coal distribution methods using ordinary baffles or static distributors, this technical solution, through a combination of centrifugal separation and adjustable blades, significantly improves the separation efficiency and concentration adjustment flexibility of pulverized coal, resulting in a substantial increase in the pulverized coal concentration on the high-concentration side, thereby effectively reducing the ignition temperature of the pulverized coal gas flow. Simultaneously, by concentrating most of the pulverized coal on the high-concentration side for staged ignition, and only sending a small amount directly into the furnace 3, it ensures energy density in the initial ignition stage while avoiding energy waste, greatly improving the W furnace's adaptability to low-volatile pulverized coal under low-load conditions.

[0037] In another technical solution, a flame status feedback device 14 is also included. The flame status feedback device 14 includes a photosensitive signal sensor, an infrared sensor, and a temperature sensor. At least one photosensitive signal sensor and at least one infrared sensor are respectively installed inside the primary combustion chamber 10, the multi-stage combustion chamber 11, or the final mixing chamber 12 to collect flame light intensity signals and flame infrared radiation signals. At least one temperature sensor is respectively installed inside the primary combustion chamber 10, the multi-stage combustion chamber 11, the final mixing chamber 12, or the furnace 3 of the W furnace to collect temperature signals. It also includes a pulverized coal concentration sensor, which is installed at the inlet of the pulverized coal concentration distribution device 5 or on the flow pipe of the high-concentration air-pulverized coal mixture 2, for collecting pulverized coal concentration signals; The flame status feedback device 14 and the pulverized coal concentration sensor output the collected signals to the remote intelligent control system.

[0038] In the above technical solution, a flame status feedback device 14 is introduced, which consists of three types of sensors: a photosensitive signal sensor, an infrared sensor, and a temperature sensor. The photosensitive signal sensor is used to sense the intensity of visible light emitted by the flame, which can determine the presence of the flame and the intensity of combustion. The infrared sensor is more sensitive to the infrared radiation of the flame and can penetrate some smoke interference, more accurately reflecting the temperature distribution and combustion stability inside the flame. The temperature sensor directly measures the temperature of the medium, providing the most intuitive thermal state parameters. In actual installation, the photosensitive signal sensor and the infrared sensor are usually installed in pairs or individually on the internal walls of the primary combustion chamber 10, the multi-stage combustion chamber 11, and the final mixing chamber 12. For example, they can be installed through openings in the side walls of each combustion chamber, with the sensor probes facing the center of the combustion chamber to avoid being blocked by ash accumulation. The temperature sensor can be in the form of a thermocouple or a resistance temperature detector (RTD). In addition to being installed in the three combustion chambers mentioned above, it can also be arranged in multiple representative locations (such as the front wall, rear wall, and arch area) within the W furnace 3.

[0039] This technical solution also includes a pulverized coal concentration sensor. This sensor can be installed on the inlet pipe of the pulverized coal concentration distribution device 5 or on the flow pipe of the high-concentration air-coal mixture 2, for real-time acquisition of the pulverized coal concentration signal in the mixture. The pulverized coal concentration sensor can employ principles such as electrostatic induction, microwave attenuation, or optical transmission. For example, an electrostatic sensor detects the charge signal generated by the friction of pulverized coal particles to infer the concentration, offering advantages such as fast response and non-contact operation. The signal output by this pulverized coal concentration sensor is also sent to the remote intelligent control system.

[0040] The flame status feedback device 14 (including photosensitive, infrared, and temperature sensors) and the pulverized coal concentration sensor output their respective collected signals (flame intensity, infrared radiation, temperature, and pulverized coal concentration) to the remote intelligent control system. This remote intelligent control system is typically deployed in a central control room or local control cabinet and has data acquisition, storage, and analysis functions. By comprehensively analyzing these multi-source signals, the system can determine whether the current combustion state is normal, whether the flame is stable, and whether the pulverized coal concentration is within a reasonable range, thus providing a basis for subsequent automatic adjustment and control decisions. For example, when the photosensitive signal fluctuates drastically and the infrared radiation remains persistently low, the system can determine this as an early sign that the flame is about to extinguish.

[0041] Compared to traditional combustion monitoring methods that rely solely on manual observation or single parameters (such as furnace negative pressure or flue gas temperature), this technical solution integrates four types of sensor signals—photosensitive, infrared, temperature, and pulverized coal concentration—to achieve comprehensive and multi-dimensional perception of the combustion process. This integrated sensing capability enables the system to identify early and accurate signs of combustion instability, greatly improving its responsiveness to changes in complex operating conditions and laying a solid data foundation for subsequent intelligent automatic control.

[0042] In another technical solution, the pulverized coal concentration distribution device 5 is equipped with a remote control mechanism; the remote control mechanism and the boiler control system are respectively communicatively connected to the remote intelligent control system; The remote intelligent control system reads the unit operating load signal and coal quality characteristics data from the boiler control system, and generates control commands based on the read data and the signals collected by the flame status feedback device 14 and sends them to the remote control mechanism. The remote control mechanism controls the adjustable distribution blades to change their deflection angle according to the received control commands, so as to dynamically adjust the distribution ratio of the high-concentration air-coal mixture 2 and the low-concentration air-coal mixture 6. The remote intelligent control system is configured to: when the signal collected by the flame status feedback device 14 indicates that the combustion is unstable, the remote control mechanism is activated first to adjust the deflection angle of the adjustable distribution blades so as to maintain stable combustion by increasing the coal powder concentration. Under low-load conditions, the coal powder concentration of the high-concentration air-coal mixture 2 is adjusted to 0.85-1.0 kg coal powder / kg air, and the coal powder fineness R90≤6%.

[0043] In the above technical solution, the pulverized coal concentration distribution device 5 is equipped with a remote control mechanism. This mechanism typically consists of an electric or pneumatic actuator and a transmission rod, capable of driving the adjustable distribution blades to rotate and change their deflection angle based on received electrical signals. This remote control mechanism communicates with a remote intelligent control system, which in turn communicates with the boiler's existing control system (i.e., the boiler control system). The boiler control system typically includes the unit's current load command, actual power output, and industrial and elemental analysis data of the coal fed into the boiler (such as volatile matter, ash content, and calorific value). The remote intelligent control system can periodically or irregularly read these unit operating load signals and coal quality characteristic data from the boiler control system; specifically, it reads the coal quality setpoints or real-time online analyzer data from the boiler control system via a communication interface.

[0044] The remote intelligent control system integrates the unit load and coal quality data it reads with signals collected by the flame status feedback device 14 (such as flame intensity, infrared radiation, and temperature) to generate control commands. These commands are then sent to the remote control mechanism of the pulverized coal concentration distribution device 5, which in turn drives the adjustable distribution blades to change their deflection angle, thereby dynamically adjusting the distribution ratio of the high-concentration air-coal mixture 2 and the low-concentration air-coal mixture 6. For example, when the unit load drops from full load to 40% of its normal load, the system detects a significant decrease in flame temperature and instructs the distribution blades to increase their deflection angle, causing more pulverized coal to be thrown towards the high-concentration side, further increasing the pulverized coal concentration on the high-concentration side from its normal value. The system is specifically configured to prioritize adjusting the distribution blades by activating the remote control mechanism when the flame status feedback signal indicates unstable combustion (such as light intensity fluctuations exceeding a preset threshold or temperature falling below a safety limit), rather than first increasing the supply of the input heat source. This strategy aims to maximize reliance on the "intrinsic" means of increasing pulverized coal concentration to maintain stable combustion, thereby reducing dependence on external auxiliary fuels.

[0045] Under low-load conditions, this technical solution provides a preferred adjustment target parameter: the coal powder concentration of the high-concentration air-coal mixture 2 is adjusted to contain 0.85 to 1.0 kg of coal powder per kg of air (i.e., 0.85-1.0 kg coal powder / kg air), while the coal powder fineness requirement R90 does not exceed 6% (R90 refers to the percentage of coal powder mass passing through a 90-micron sieve; the smaller the value, the finer the coal powder). The coal powder concentration of 0.85-1.0 is a reference range, which can be finely adjusted according to the volatile matter content of the coal type during actual operation. For example, for ultra-low volatile matter anthracite with less than 10% volatile matter, the optimal value can be 0.95 coal powder / kg air; for lean coal with about 15% volatile matter, 0.88 coal powder / kg air can be used. A coal powder fineness R90 ≤ 6% is a prerequisite for ensuring rapid ignition of the high-concentration coal powder; this requirement should be ensured during operation through regular sampling and testing or online particle size monitoring.

[0046] Compared to traditional pulverized coal burners with a fixed separation ratio, this technical solution achieves dynamic adaptive adjustment of the separation ratio based on changes in unit load and coal quality through the linkage of a remote intelligent control system and adjustable distribution blades. When combustion is unstable, the strategy of prioritizing increased pulverized coal concentration rather than adding external heat sources allows the system to significantly reduce auxiliary fuel consumption under low loads, thereby significantly improving operational economy. Simultaneously, precisely controlling the pulverized coal concentration at 0.85-1.0 pulverized coal / kg air under low loads, coupled with high fineness requirements, effectively lowers the ignition temperature limit of the pulverized coal, enabling the W boiler to maintain stable combustion even under deep peak-shaving conditions, greatly expanding the boiler's low-load operating range.

[0047] In another technical solution, the input heat source device 1 includes an input heat source main chemical agent inlet 8, an input heat source auxiliary chemical agent inlet 13, and an input heat source enhancing reactant inlet 9; the input heat source main chemical agent is at least one of hydrogen, natural gas, ammonia, Brown gas, or fuel oil, used to provide initial ignition energy; the input heat source auxiliary chemical agent is air, oxygen, or compressed air, used to physically disperse the input heat source main chemical agent and provide initial reaction conditions; the input heat source enhancing reactant is air, oxygen, or compressed air, used to enhance the reaction intensity of the input heat source main chemical agent and prevent nozzle burn-out.

[0048] In the above technical solution, the input heat source device 1 includes three independent chemical agent inlets: the main chemical agent inlet 8, the auxiliary chemical agent inlet 13, and the reaction enhancer inlet 9. The main chemical agent is the primary fuel providing initial ignition energy and can be at least one of hydrogen, natural gas, ammonia, Brown gas (a hydrogen-oxygen mixture), or fuel oil. In practical applications, to balance environmental protection and performance, hydrogen or Brown gas is preferred because its combustion product is water vapor, with no carbon emissions; natural gas or fuel oil are also common choices considering cost and safety. The auxiliary chemical agent uses air, oxygen, or compressed air, and its main functions are twofold: first, to disperse and physically disperse the main chemical agent stream through high-speed injection, forming a more uniform flame front and avoiding localized high temperatures or incomplete combustion; second, to provide the oxidant required for the initial reaction, especially when the main chemical agent is hydrogen or natural gas, the oxygen in the auxiliary chemical agent supports its initial combustion. The reinforcing agent also uses air, oxygen, or compressed air, but its purpose is different: it is used to inject additional oxidant into the root of the flame after combustion has been established, thereby enhancing the reaction intensity of the main chemical agent and making the flame temperature higher and more stable; at the same time, by increasing the flow rate of the reinforcing agent, a cooling gas film can be formed at the nozzle outlet to prevent the nozzle metal material from being burned by high-temperature flame backfire.

[0049] The control valves for the three inlets are typically solenoid valves or regulating valves, with flow rates independently adjusted by a remote intelligent control system. During operation, the auxiliary chemical agent (such as compressed air) is first activated, followed by the main chemical agent in a tiered manner. Once the flame stabilizes, the enhancing reactant is gradually added. For example, in the initial ignition stage, the auxiliary chemical agent flow rate is set to 30% of the total flow rate, 20% of the main chemical agent is added, and the enhancing reactant is not added initially, resulting in a gentle small flame. Once the temperature within the primary combustion chamber rises, the main chemical agent and enhancing reactant are added simultaneously to intensify the flame.

[0050] Compared to traditional ignition methods that use only a single fuel nozzle (such as an oil nozzle or a natural gas nozzle), this technical solution achieves flexible adjustment of flame intensity, dispersion, and cooling effect by independently controlling the heat source in three paths: the main chemical agent, the auxiliary chemical agent, and the enhancing reactant. This structure effectively avoids localized overheating or nozzle burnout, significantly improving the service life and safety of the input heat source device 1. Simultaneously, through the physical dispersion effect of the auxiliary chemical agent, the mixing uniformity of the main chemical agent and high-concentration pulverized coal is significantly improved, greatly enhancing the success rate and stability of pulverized coal ignition.

[0051] In another technical solution, the remote intelligent control system is also communicatively connected to each chemical inlet valve of the input heat source device 1 and the wind speed regulating device of the combustion auxiliary air; the remote intelligent control system automatically adjusts the input heat source supply, coal powder separation ratio and combustion auxiliary air speed according to the real-time monitored temperature, coal powder concentration and flame intensity of the primary combustion chamber 10, the multi-stage combustion chamber 11 and the final mixing chamber 12, so as to achieve on-demand supply.

[0052] In the above technical solution, the remote intelligent control system can not only control the blades of the pulverized coal concentration distribution device 5, but also independently control the flow valves of the main chemical agent, auxiliary chemical agent, and enhancing reactant, as well as adjust the wind speed of the combustion auxiliary air (e.g., through a variable frequency fan or regulating baffle). These communication connections typically use industrial fieldbuses (such as Profibus, Modbus TCP / IP) to achieve real-time data exchange.

[0053] The remote intelligent control system monitors the temperature, pulverized coal concentration, and flame intensity of the primary combustion chamber 10, multi-stage combustion chamber 11, and final mixing chamber 12 in real time. These parameters are obtained from various sensors: temperature sensors provide the actual temperature values ​​of each chamber, pulverized coal concentration sensors provide the concentration signal from the high-concentration pipeline, and flame intensity is comprehensively evaluated by photosensitive and infrared sensors. The remote intelligent control system compares these real-time data with preset target values.

[0054] The remote intelligent control system automatically adjusts the input heat source supply (by adjusting the valve openings of the main chemical agent, auxiliary chemical agent, and enhancing reactant), the pulverized coal separation ratio (by adjusting the angle of the distribution blades), and the combustion auxiliary air velocity based on the comparison results to achieve on-demand supply. In specific implementation, closed-loop PID control or a more advanced fuzzy logic control strategy can be adopted. For example, when the flame intensity in the multi-stage combustion chamber 11 is detected to be weak but the pulverized coal concentration is normal, the input heat source supply is increased first; if the pulverized coal concentration is low, the separation ratio is adjusted first to increase the concentration; if the combustion chamber temperature is too high, the auxiliary air is appropriately increased or the main chemical agent is reduced. These three sets of parameters are adjusted in a coordinated manner to achieve stable combustion while minimizing energy consumption.

[0055] Compared to traditional manual or semi-automatic adjustment methods, this technical solution achieves coordinated and precise control of the input heat source, pulverized coal distribution, and combustion auxiliary air through a three-parameter linkage feedback control system of temperature, concentration, and flame. This "on-demand" intelligent adjustment method can significantly reduce the waste of auxiliary fuel and electricity. At the same time, due to its fast response speed and accurate adjustment, it can effectively suppress the amplitude of combustion fluctuations, enabling the W boiler to maintain flame stability even when the load changes frequently, greatly improving the operational reliability and economy under deep peak shaving conditions.

[0056] In another technical solution, a staged adjustment device 15 is provided on the outside of the multi-stage combustion chamber 11. The staged adjustment device 15 includes at least one set of rotatable baffles. The baffles extend into the interior of the multi-stage combustion chamber 11. Each baffle is rotatably arranged around its own rotation axis, and the rotation axis is perpendicular to the axis of the multi-stage combustion chamber 11. The deflection angle of the baffles is adjustable in the range of 0° to 60°. By changing the deflection angle, the projected area of ​​the baffles in the airflow direction is adjusted, thereby selectively shielding or opening part of the combustion passage of the multi-stage combustion chamber 11 and applying a turbulent effect to the internal airflow.

[0057] In the above technical solution, a staged adjustment device 15 is provided on the outside of the multi-stage combustion chamber 11. This staged adjustment device 15 includes at least one set of rotatable baffles that extend into the interior of the multi-stage combustion chamber 11. The rotation axis of the blades is perpendicular to the axis of the multi-stage combustion chamber 11, meaning that the blades can deflect left and right or up and down within the airflow channel like small doors, rather than rotating parallel to the axis like guide vanes. In actual structures, multiple baffles are typically arranged circumferentially along the multi-stage combustion chamber 11, forming a ring of adjustable louver-like structures.

[0058] The deflection angle of the spoiler blades is adjustable within the range of 0° to 60°. 0° represents the blade plane being parallel to the airflow direction, producing almost no obstruction; 60° represents the blade deflecting to its maximum angle with the airflow direction, creating significant obstruction and turbulence. By changing the deflection angle, the projected area of ​​the blades in the airflow direction can be adjusted, i.e., the effective blocking area of ​​the blades facing the airflow. When the blade angle increases, the projected area increases, more airflow channels are blocked, and strong vortices and turbulence are generated when the airflow passes over the blade edges. Conversely, when the angle decreases, the channels open, and the flow resistance decreases. In specific implementation, the graded adjustment device 15 can be equipped with an electric actuator to automatically adjust the angle according to the load command. For example, at a low load of 30%, the blade deflection angle is adjusted to 45° to block most of the combustion channels, reduce the heat dissipation area, and concentrate heat to maintain the core flame; at a high load of 80%, the blades are adjusted to 10°, almost fully open to reduce resistance. The optimal commonly used angle is 30°, which balances a certain amount of turbulence mixing effect and moderate flow capacity.

[0059] The function of the staged adjustment device 15 is to selectively shield or open part of the combustion passages of the multi-stage combustion chamber 11 and to apply turbulence to the internal airflow. Shielding the passages reduces heat exchange between the high-temperature flue gas and the relatively low-temperature outer wall of the combustion chamber, thus reducing heat loss; simultaneously, the turbulence disrupts the airflow organization, allowing unburned pulverized coal to mix more thoroughly with the high-temperature flue gas, accelerating the combustion reaction. This staged adjustment allows the multi-stage combustion chamber 11 to flexibly adjust the combustion intensity and heat dissipation loss according to load requirements.

[0060] Compared to traditional non-adjustable multi-stage combustion chambers 11, this technical solution utilizes rotatable turbulence blades to allow the combustion chamber to adjust its effective flow area and turbulence intensity under different loads. At low loads, the partially shielded channels significantly reduce heat loss, improve the core flame's sustaining ability, and effectively prevent flameout. At high loads, the fully open channels ensure sufficient gas flow and low resistance. Simultaneously, the turbulence promotes mixing of pulverized coal and high-temperature flue gas, resulting in a significant improvement in combustion efficiency and expanding the stable operating load range of the unit.

[0061] In another technical solution, the combustion auxiliary air channel 7 is located on the periphery of the multi-stage combustion chamber 11, and the wind speed and air volume of the combustion auxiliary air are controlled independently of the high-concentration air-coal mixture 2; the combustion auxiliary air forms an air-coil flame structure on the outside of the multi-stage combustion chamber 11 to provide air support for the complete combustion of pulverized coal in the W furnace 3.

[0062] In the above technical solution, the combustion auxiliary air duct 7 is positioned around the periphery of the multi-stage combustion chamber 11. "Periphery" refers to the auxiliary air duct surrounding the outside of the multi-stage combustion chamber 11, typically in the form of an annular sleeve structure or multiple branches evenly distributed circumferentially. This arrangement ensures that the auxiliary air is not injected from the center, but rather from the periphery towards the center or along the wall. The velocity and volume of the combustion auxiliary air can be controlled independently of the high-concentration air-coal mixture 2; that is, they have independent regulating valves or fan frequency converters and are unaffected by changes in the air volume delivered by the high-concentration air-coal mixture 2.

[0063] The auxiliary combustion air forms a flame-enveloping structure on the outside of the multi-stage combustion chamber 11. A flame-enveloping structure refers to the auxiliary air being ejected at high speed from the periphery, forming an air curtain or rotating ring around the flame column, thus enveloping the central flame. This structure serves two purposes: first, the high-speed airflow on the periphery compresses and stabilizes the central flame, preventing it from detaching or dissipating; second, oxygen in the auxiliary air gradually enters the core flame region through diffusion and turbulent mixing, rather than directly impacting the flame root and causing cooling and extinguishing. In actual operation, the auxiliary air velocity is typically set to 1.2 to 1.5 times the velocity of the high-concentration air-powder mixture 2 to achieve an effective enveloping effect.

[0064] The combustion auxiliary air is used to provide air support for the complete combustion of pulverized coal in the W furnace furnace 3. This means that in the multi-stage combustion chamber 11, the auxiliary air mainly plays the role of flame stabilization and premixing oxygen, while most of the final oxygen required for combustion still needs to be supplied in the W furnace furnace 3 through secondary air and other means. However, the air-coil flame structure formed in the multi-stage combustion chamber 11 ensures that the flame leaving the final mixing chamber 12 and entering the furnace 3 already has a relatively high temperature and a certain oxygen content, which is conducive to rapid mixing with the secondary air in the furnace 3 to complete the final combustion.

[0065] Compared to traditional methods that directly supply auxiliary air from the center or simply from the side, this technical solution creates a unique wind-wrapped flame structure through an outer annular air duct and independent wind speed control. This structure significantly improves the rigidity and disturbance resistance of the flame, making it less susceptible to being extinguished by negative pressure fluctuations or low-temperature airflow within the furnace. Simultaneously, because the auxiliary air does not directly impact the flame root, it avoids the incomplete combustion or flameout problems caused by cooling effects in traditional methods, thereby greatly improving the stability and burnout rate of pulverized coal combustion under low loads.

[0066] In another technical solution, the amount of the main chemical agent used in the input heat source is controlled by gradually increasing it in stages at proportions of 20%, 40%, 60%, 80%, and 100%.

[0067] In the aforementioned technical solution, the amount of main chemical agent used in the input heat source is controlled by gradually increasing it in five stages: 20%, 40%, 60%, 80%, and 100%. "Gradually increasing" means that during ignition or load adjustment, the main chemical agent flow rate is not increased to the target value all at once, but rather gradually increased according to the aforementioned percentages. A certain time interval should be maintained between each stage, typically 5 to 15 seconds, to allow the temperature and flame state in the combustion chamber to reach a new equilibrium before proceeding to the next stage.

[0068] In actual operation, when it is necessary to start the input heat source device 1 or increase its output, the remote intelligent control system first turns on the auxiliary chemical agent (such as air). After the flow rate stabilizes, the main chemical agent valve is opened to 20% of the target flow rate. At this time, a small flame is formed in the primary combustion chamber 10. Due to the very low heat load, even if the high concentration of high-concentration coal powder is high, deflagration or backfire will not occur. The system monitors whether the flame is burning stably through the flame status feedback device 14. After confirming stability, the flow rate is increased to 40%, and so on. Before each increase, the status of the previous level must be confirmed to be normal. If flame fluctuations or abnormal temperature drops occur in a certain stage, the system can pause the increase, maintain the current stage, or reduce the stage, and try to increase again after stabilization. When reducing the load or stopping the input heat source, the decrease can also be performed step by step in the reverse order. This step-by-step control is also applicable to the switching of the main chemical agent type. For example, when switching from natural gas to hydrogen, the transition can be smooth by gradually mixing in the main chemical agent.

[0069] Compared to the traditional method of adding the main chemical agent all at once, this technical solution effectively avoids deflagration, backfire, or localized overheating caused by the instantaneous accumulation of fuel in the early stages of combustion through stepwise, controlled addition. This significantly improves the safety of the input heat source device 1. Simultaneously, this refined addition method allows the amount of main chemical agent to be precisely matched to the actual required ignition energy, significantly reducing auxiliary fuel waste while ensuring reliable ignition. Especially under deep peak-shaving conditions, the system can select to add only a lower step (e.g., 40% or 60%) based on the actual temperature of the furnace 3 to maintain self-sustaining combustion of pulverized coal, thereby achieving significant energy-saving effects.

[0070] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0071] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A W-type pulverized coal combustion heat source input device, characterized in that, include: An eccentric reducer, the inlet of which is used to receive the air-coal mixture output from the air-coal system; A pulverized coal concentration distribution device, the inlet of which is connected to the outlet of the eccentric reducer, the pulverized coal concentration distribution device having a high-concentration air-coal mixture outlet and a low-concentration air-coal mixture outlet, the low-concentration air-coal mixture outlet being used to connect to the furnace of the W furnace; A primary combustion chamber has a primary chamber first inlet, a primary chamber second inlet, and a primary chamber outlet, wherein the primary chamber first inlet is connected to the high-concentration air-coal mixture outlet of the pulverized coal concentration distribution device; An input heat source device is provided, the output of which is connected to the second inlet of the primary chamber, for providing a high-temperature heat source to the primary combustion chamber. A multi-stage combustion chamber has a first inlet, a second inlet, a third inlet, and an outlet. The first inlet is connected to the outlet of the primary chamber, and the second inlet is connected to the outlet of the high-concentration air-coal mixture of the pulverized coal concentration distribution device. The final mixing chamber has a mixing chamber inlet and a mixing chamber outlet, the mixing chamber inlet being connected to the multi-stage chamber outlet and the mixing chamber outlet being connected to the furnace of the W furnace; The combustion auxiliary air duct has its outlet connected to the third inlet of the multi-stage chamber.

2. The W-furnace pulverized coal combustion heat source input device as described in claim 1, characterized in that, The pulverized coal concentration distribution device is a centrifugal separator with adjustable distribution blades inside. The air-powder mixture accelerated by the eccentric reducer enters the pulverized coal concentration distribution device, where the pulverized coal is separated along the directional flow direction of the adjustable distribution blades under centrifugal force. The pulverized coal concentration distribution device separates 50% of the total air and 10%-15% of the total pulverized coal in the air-powder mixture into the low-concentration air-powder mixture, and separates the remaining 50% of the air and 85%-90% of the pulverized coal into the high-concentration air-powder mixture.

3. The W-type pulverized coal combustion heat source input device as described in claim 2, characterized in that, It also includes a flame status feedback device, which comprises: a photosensitive signal sensor, an infrared sensor, and a temperature sensor; at least one of the photosensitive signal sensors and at least one of the infrared sensors are respectively installed inside the primary combustion chamber, the multi-stage combustion chamber, or the final mixing chamber to collect flame light intensity signals and flame infrared radiation signals; at least one temperature sensor is respectively installed inside the primary combustion chamber, the multi-stage combustion chamber, the final mixing chamber, or the furnace chamber of the W furnace to collect temperature signals; It also includes a pulverized coal concentration sensor, which is installed at the inlet of the pulverized coal concentration distribution device or on the flow pipe of the high-concentration air-coal mixture, for collecting pulverized coal concentration signals; The flame status feedback device and the pulverized coal concentration sensor output the collected signals to the remote intelligent control system.

4. The W-type pulverized coal combustion heat source input device as described in claim 3, characterized in that, The pulverized coal concentration distribution device is equipped with a remote control mechanism; the remote control mechanism and the boiler control system are respectively connected to the remote intelligent control system. The remote intelligent control system reads the unit operating load signal and coal quality characteristics data from the boiler control system, and generates control commands based on the read data and the signals collected by the flame status feedback device, and sends them to the remote control mechanism. The remote control mechanism controls the adjustable distribution blades to change their deflection angle according to the received control commands, so as to dynamically adjust the distribution ratio of the high-concentration air-powder mixture and the low-concentration air-powder mixture. The remote intelligent control system is configured to: when the signal collected by the flame status feedback device indicates that the combustion is unstable, the remote control mechanism is activated first to adjust the deflection angle of the adjustable distribution blades, so as to maintain stable combustion by increasing the coal powder concentration. Under low-load conditions, the coal powder concentration of the high-concentration air-coal mixture is adjusted to 0.85-1.0 kg coal powder / kg air, and the coal powder fineness R90≤6%.

5. The W-type pulverized coal combustion heat source input device as described in claim 3, characterized in that, The input heat source device includes an input heat source main chemical agent inlet, an input heat source auxiliary chemical agent inlet, and an input heat source enhancing reactant inlet; the input heat source main chemical agent is at least one of hydrogen, natural gas, ammonia, Brown gas, or fuel oil, used to provide initial ignition energy; the input heat source auxiliary chemical agent is air, oxygen, or compressed air, used to physically disperse the input heat source main chemical agent and provide initial reaction conditions; the input heat source enhancing reactant is air, oxygen, or compressed air, used to enhance the reaction intensity of the input heat source main chemical agent and prevent nozzle burn-out.

6. The W-type pulverized coal combustion heat source input device as described in claim 5, characterized in that, The remote intelligent control system is also connected to the chemical inlet valves of the input heat source device and the wind speed adjustment device of the combustion auxiliary air. The remote intelligent control system automatically adjusts the input heat source supply, coal powder separation ratio and combustion auxiliary air speed according to the temperature, coal powder concentration and flame intensity of the primary combustion chamber, the multi-stage combustion chamber and the final mixing chamber monitored in real time, so as to achieve on-demand supply.

7. The W-type pulverized coal combustion heat source input device as described in claim 1, characterized in that, The multi-stage combustion chamber is provided with a staged adjustment device on its exterior. The staged adjustment device includes at least one set of rotatable baffles. The baffles extend into the interior of the multi-stage combustion chamber. Each baffle is rotatably arranged around its own rotation axis, and the rotation axis is perpendicular to the axis of the multi-stage combustion chamber. The deflection angle of the deflection blades is adjustable within the range of 0° to 60°. By changing the deflection angle, the projected area of ​​the deflection blades in the airflow direction can be adjusted, thereby selectively blocking or opening part of the combustion passage of the multi-stage combustion chamber and applying a turbulence effect to the internal airflow.

8. The W-type pulverized coal combustion heat source input device as described in claim 1, characterized in that, The combustion auxiliary air duct is located on the periphery of the multi-stage combustion chamber, and the wind speed and volume of the combustion auxiliary air are controlled independently of the high-concentration air-coal mixture. The combustion auxiliary air forms an air-coil flame structure on the outside of the multi-stage combustion chamber to provide air support for the complete combustion of pulverized coal in the W furnace.

9. The W-type pulverized coal combustion heat source input device as described in claim 5, characterized in that, The output end of the input heat source device extends into the interior of the primary combustion chamber at an angle downwards.

10. The W-type pulverized coal combustion heat source input device as described in claim 1, characterized in that, The amount of the main chemical agent used in the input heat source is controlled by gradually increasing the input in stages at proportions of 20%, 40%, 60%, 80%, and 100%.

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