All-solid-state microwave plasma torch coal powder boiler ignition apparatus, boiler and method

Abstract

The application discloses full-solid-state microwave plasma torch coal powder boiler ignition equipment, a boiler and a method, solves the problem that the microwave torch in the prior art is mostly vertical and cannot meet the coal powder boiler horizontal deep position ignition and has poor operation stability, has the beneficial effects of meeting the coal powder boiler horizontal deep position ignition requirement, improving the start-stop reliability and continuous operation stability, and specifically has the following scheme: the full-solid-state microwave plasma torch coal powder boiler ignition equipment comprises a full-solid-state microwave source, the full-solid-state microwave source is connected with a plasma generator through a waveguide transmission assembly and a waveguide directional section, a torch head is arranged at the end of the plasma generator, the torch head can be located in a coal powder-air mixing area of a boiler hearth to concentrate high-temperature plasma energy on the coal powder-air mixing area, the torch head is sequentially provided with an isolation and load absorption component and an automatic tuner along the waveguide transmission assembly, the automatic tuner is connected with the waveguide directional section so that the torch generated by the torch head is output along the radial direction of the boiler hearth.

Description

Technical Field

[0001] This invention relates to the field of boiler clean ignition technology, and in particular to ignition equipment, boiler and method for all-solid-state microwave plasma torch pulverized coal boilers. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Pulverized coal boilers are core thermal equipment in industries such as power, metallurgy, and chemicals. During start-up, shutdown, and low-load phases, they typically rely on heavy oil or natural gas for ignition and stable combustion, resulting in problems such as high fuel costs, concentrated emissions during start-up and shutdown, and system complexity. DC electrode plasma ignition can achieve oil-free ignition to some extent, but electrode erosion and slagging can cause output drift, frequent maintenance, and limited lifespan. At the same time, dust, high temperatures, and strong airflow disturbances in the furnace can further accelerate electrode wear and affect flare stability.

[0004] Microwave plasma ignition devices have great potential due to their electrode-free nature and fast response. However, applying microwave plasma ignition devices to boilers faces the following difficulties: The boiler has a relatively small ignition port. Existing microwave plasma ignition devices have a relatively high structure and cannot be adapted to the small ignition port. Moreover, the boiler ignition area is usually located downstream of the burner nozzle. This area is distributed radially along the furnace and is not located near the furnace wall. With the traditional vertical torch structure, the plasma is mainly released in the vertical direction, which makes it difficult to penetrate the primary air and pulverized coal jet. It is also difficult to stably arrange the high-temperature active zone in the core reaction zone where the pulverized coal concentration and oxygen content are matched. The torch energy is easily dissipated near the furnace wall, resulting in ignition delay, local overheating, flame miss, and reduced combustion stability. In addition, traditional microwave torches have relatively low power levels, resulting in poor operational stability during continuous high-power operation. They are also prone to matching difficulties and insufficient heat dissipation, failing to meet the engineering requirements for long-cycle operation and multi-condition adaptive operation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide an all-solid-state microwave plasma torch ignition system for pulverized coal boilers, which is a high-power microwave plasma ignition device capable of stable coupling under varying load conditions, directional torch output, and complete thermal management and online closed-loop control.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: The all-solid-state microwave plasma torch ignition equipment for pulverized coal boilers includes an all-solid-state microwave source, which is connected to a plasma generator via a waveguide transmission component and a waveguide directional section. A torch head is installed at the end of the plasma generator, with the central axis of the torch head parallel to the main body of the waveguide transmission component. The torch head and part of the waveguide transmission component can pass through the boiler's ignition port. The torch head is located in the pulverized coal-air mixing zone of the boiler furnace to concentrate high-temperature plasma energy in the pulverized coal-air mixing zone. Isolation and load absorption components and an automatic tuner are sequentially installed in the waveguide transmission component. The automatic tuner is connected to the waveguide directional section so that the torch generated by the torch head is output along the radial direction of the boiler furnace. The all-solid-state microwave source, plasma generator, and waveguide transmission component are each individually connected to a control unit.

[0007] In the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment described above, the ignition point generated by the torch head is located on the central axis of the boiler furnace.

[0008] As described above, the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment includes a waveguide directional section comprising a straight waveguide and a bent waveguide, which are connected together. The bent waveguide is bent at 90° and connected to an extended coupling section, which is connected to the plasma generator. The extended coupling section is used to make the plasma generator higher than the waveguide transmission component.

[0009] As described above, in the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment, the isolation and load absorption component is a conversion waveguide used to introduce the reflected power into the water load for absorption in the event of reflected waves or abnormal mismatch. The dual directional coupler is used to acquire incident power and reflected power signals respectively; the automatic tuner uses an adjustable matching structure to dynamically adjust the waveguide equivalent impedance.

[0010] The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment described above also includes a gas supply mechanism, which is connected to the control unit and the plasma generator. The plasma generator is provided with a tangential gas supply channel to tangentially introduce working gas into the plasma generator to form a swirling stable field.

[0011] The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment described above also includes a cooling mechanism, which includes a cooling circuit located at the all-solid-state microwave source, and a water-cooling structure located on the waveguide directional section and the outer wall of the plasma generator.

[0012] The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment described above also includes a real-time monitoring unit. The real-time monitoring unit includes a first temperature sensor located on the side wall of the plasma generator, a second temperature sensor, a flow sensor, and a pressure sensor located at the inlet and outlet pipes of the cooling mechanism, and each sensor is connected to the control unit. The real-time monitoring unit also includes a power meter or a dual-directional coupler, which is connected to the control unit and between the automatic tuner and the isolation and load absorption components. The power meter or dual-directional coupler collects the incident / reflected power in real time and sends the collected incident / reflected power to the control unit. The control unit compares the collected incident / reflected power with a set threshold. When the control unit determines that the reflected power deviates from the set threshold, the real-time monitoring unit drives the automatic tuner to perform optimization matching, thereby reducing the reflected power.

[0013] Secondly, the present invention provides a high-power all-solid-state microwave plasma torch pulverized coal boiler. An ignition port is provided on the side wall of the boiler furnace. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment is installed through the ignition port. The distance between the plasma generator and the waveguide directional section in the ignition equipment is adapted to the height of the ignition port. The all-solid-state microwave source is placed outside the boiler furnace through the ground. The torch head and the waveguide directional section pass through the ignition port and are located inside the boiler furnace.

[0014] The high-power all-solid-state microwave plasma torch pulverized coal boiler described above uses a support frame to support the waveguide transmission component.

[0015] Thirdly, the present invention also provides an ignition method for a pulverized coal boiler, employing an all-solid-state microwave plasma torch pulverized coal boiler ignition device, comprising the following: The all-solid-state microwave source is placed on the outside of the boiler furnace via the ground, the torch head and waveguide directional section pass through the ignition port and are located inside the boiler furnace, and the outlet end of the plasma generator is set close to the ignition point. Turn on the all-solid-state microwave source, the load absorption component in the waveguide transmission assembly, the dual directional coupler and the automatic tuner. The all-solid-state microwave source serves as the energy input end, outputting continuous wave microwave power that can be adjusted within a preset range. The microwave energy is coupled to the plasma generator through the waveguide transmission assembly. The plasma generator is turned on to stimulate the plasma, and impedance matching is achieved through the automatic tuner to form a stable horizontal directional plasma torch and align it with the ignition area of ​​the boiler furnace. Ignition and stable combustion are carried out under the condition of air-assisted coal feeding. After ignition, the power of the all-solid-state microwave source is gradually reduced or shut down according to the boiler furnace temperature and load requirements.

[0016] The beneficial effects of the present invention are as follows: The ignition equipment of this invention is adaptable to the size of the boiler ignition port, allowing it to pass through the ignition port and enter the boiler interior. The entire system includes a solid-state microwave source, which is connected to a plasma generator via a waveguide transmission assembly and a waveguide directional section. The waveguide transmission assembly contains an isolation and load absorption component and an automatic tuner. The isolation and load absorption component directs reflected power into a water load for absorption in case of reflected waves or abnormal mismatches. The automatic tuner dynamically adjusts the waveguide's equivalent impedance. The waveguide transmission assembly maintains stable coupling as the discharge load changes with operating conditions, reducing the impact of reflected power on the solid-state microwave source and improving start-up and shutdown reliability. Continued operational stability; a torch head is installed at the end of the plasma generator, which can be located in the coal-air mixing zone of the boiler furnace to concentrate the high-temperature plasma energy on the coal-air mixing zone, realizing horizontal directional output of the torch. In other words, by setting up the plasma generator and the waveguide directional section, the torch action area can be arranged at the target ignition position in the furnace, so that the ignition point is arranged in the core area of ​​the coal-air mixing flow in the furnace, so that the high-temperature plasma zone, the active particle zone and the dense phase zone of the coal powder coincide, thereby improving ignition reliability, shortening ignition response time and enhancing resistance to airflow disturbance, effectively improving the adaptability of ignition position and the flexibility of modification. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of an all-solid-state microwave plasma torch pulverized coal boiler ignition device according to one or more embodiments of the present invention.

[0019] Figure 2 This is a front view of the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to one or more embodiments of the present invention.

[0020] Figure 3 This is a top view of the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to one or more embodiments of the present invention.

[0021] Figure 4 This is a schematic diagram of the plasma generator in the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to one or more embodiments of the present invention.

[0022] Figure 5 This is a partial cross-sectional schematic diagram of the plasma generator in the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to one or more embodiments of the present invention.

[0023] Figure 6 This is a schematic diagram of an all-solid-state microwave plasma torch pulverized coal boiler according to one or more embodiments of the present invention.

[0024] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0025] The components are: 1. Microwave power supply cabinet, 2. All-solid-state microwave source, 3. Isolator, 4. Conversion waveguide, 5. Dual directional coupler, 6. Automatic tuner, 7. Bent waveguide, 8. Straight waveguide, 9. Plasma generator, 10. Boiler furnace, 11. Support base, 12. Support frame, 13. Extended coupling section, 14. Directional torch outlet, 15. Inlet pipe, 16. Gas inlet, 17. Ignition point, 18. Air compressor, 19. Water cooling mechanism, 20. Ignition port, 21. Dielectric tube, 22. Water cooling section, 23. Plasma generation chamber, 24. Inlet component, 25. Guide section, 26. Exciter. Detailed Implementation

[0026] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. As introduced in the background section, existing microwave torches are mostly vertical torches, which cannot meet the problems of lateral deep ignition and poor operational stability of pulverized coal boilers. In order to solve the above technical problems, this invention proposes an all-solid-state microwave plasma torch ignition device for pulverized coal boilers.

[0028] Example 1 In a typical embodiment of the present invention, reference is made to Figure 1 , Figure 2 and Figure 3As shown, the all-solid-state microwave plasma torch ignition equipment for pulverized coal boiler includes an all-solid-state microwave source 2. The all-solid-state microwave source 2 is connected to a plasma generator 9 through a waveguide transmission component and a waveguide directional section. A torch head is provided at the end of the plasma generator 9. The central axis of the torch head is parallel to the main body of the waveguide transmission component. The torch head and part of the waveguide transmission component can pass through the ignition port of the boiler. The torch head is located in the pulverized coal-air mixing zone of the boiler furnace to concentrate the high-temperature plasma energy on the pulverized coal-air mixing zone. An isolation and load absorption component and an automatic tuner 6 are arranged sequentially in the waveguide transmission component. The automatic tuner 6 is connected to the waveguide directional section so that the torch generated by the torch head is output along the radial direction of the boiler furnace 10. The all-solid-state microwave source 2, the plasma generator 9, and the waveguide transmission component are each connected to a control unit separately.

[0029] The equipment provided in this embodiment uses an all-solid-state microwave source 2 as the energy input terminal, outputs continuous wave microwave power and adjusts it within a preset range; the microwave energy is coupled to the plasma generator 9 through the waveguide transmission component, and a stable microwave plasma torch is excited under electrode-free conditions to achieve rapid ignition and stable combustion support for the coal powder / primary air mixed flow.

[0030] It should be noted that, in order to ensure link safety and energy utilization under high power conditions, isolation and load absorption components 4, dual directional couplers 5 and automatic tuners 6 are sequentially installed in the waveguide transmission assembly between the all-solid-state microwave source 2 and the plasma generator 9. The three are connected in sequence. Specifically, each component has a flange structure at its end, and the connection between adjacent components is achieved through the flange structure. Among them, the isolation and load absorption components are used to introduce the reflected power into the water load for absorption when there is a reflected wave or abnormal mismatch, so as to avoid the reflected energy backflow and damage to the all-solid-state microwave source. The isolation and load absorption components specifically adopt isolator 3 and conversion waveguide 4. The conversion waveguide 4 adopts BJ22-BJ26 (Huiyan Microwave full series) conversion waveguide. The dual directional coupler 5 is also a component of the real-time detection unit. The dual directional coupler 5 is used to collect the incident power and reflected power signals respectively and output them to the real-time monitoring unit. The automatic tuner 6 adopts an adjustable matching structure (such as a three-pin tuner or an equivalent adjustable short-circuit / capacitor structure) to dynamically adjust the waveguide equivalent impedance to achieve impedance matching between the all-solid-state microwave source, waveguide, and reactor. Through the setting of the waveguide transmission components, the equipment provided in this embodiment can maintain stable coupling when the discharge load changes with the operating conditions, reduce the impact of reflected power on the microwave source, and improve start-up and shutdown reliability and continuous operation stability.

[0031] It should be noted that the dual directional coupler 5 can also be replaced by a power meter. The power meter or dual directional coupler 5 is connected to the control unit to collect incident / reflected power in real time. The power meter or dual directional coupler 5 sends the collected incident / reflected power to the control unit. The control unit compares the collected incident / reflected power with a set threshold. When the control unit determines that the reflected power deviates from the set threshold, the real-time monitoring unit drives the automatic tuner 6 to perform optimization matching (using existing step scan or gradient optimization strategies) to reduce the reflected power to a safe range.

[0032] To meet the injection attitude and penetration depth required for boiler furnace ignition, this equipment is equipped with a waveguide directional section and an extended coupling section 13 at the torch end. The waveguide directional section and the extended coupling section 13 are connected. The waveguide directional section includes a straight waveguide 8 and a bent waveguide 7 connected in sequence. The ends of the straight waveguide 8 and the bent waveguide 7 are also equipped with flange structures to achieve the connection between the two. One end of the straight waveguide 8 is connected to one end of the automatic tuner 6, and the bent waveguide 7 achieves a 90° bend. Of course, the waveguide directional section can also adopt other equivalent steering structures.

[0033] It should be explained that the extended coupling section 13 has a set length. Specifically, the extended coupling section 13 is an extended tube. The shape of the transverse cross section of the extended coupling section 13 is the same as or different from the shape of the longitudinal cross section of the straight waveguide 8. The extended coupling section 13 raises the height of the plasma generator 9. A support base 11 is provided at the end of the extended coupling section 13 to support the plasma generator 9. The bottom of the support base is connected to the extended coupling section 13 through a flange structure. The top of the support base 11 is a ring structure to support the plasma generator. An opening is provided at the bottom of the ring structure of the support base to communicate with the plasma generator.

[0034] The plasma torch is converted from a vertical torch to a horizontal directional jet by the waveguide directional section, and can be used with the extended coupling section to achieve directional ignition of the torch deep into the furnace. The extended coupling section 13 makes the outlet of the plasma generator 9 a "directional torch outlet 14", which is used to concentrate the high-temperature plasma energy onto the coal powder-air (or coal powder-primary air) mixing zone, igniting the coal powder to form an ignition point 17. The distance between the ignition point 17 and the boiler side wall is determined according to the boiler structure, which effectively improves the ignition reliability and shortens the ignition response time. The torch action area is arranged at the target ignition position in the furnace, improving the adaptability of the ignition position and the flexibility of modification.

[0035] In this embodiment, the real-time monitoring unit includes a first temperature sensor located on the side wall of the plasma generator 9, a second temperature sensor, a flow sensor, and a pressure sensor located at the cooling water inlet pipe and the cooling water outlet pipe. Each sensor is connected to the control unit. The real-time monitoring unit sends the collected data to the control unit, which is a PLC controller or other type of controller. Regarding the discharge gas supply, the gas supply mechanism is connected to the control unit. Specifically, the gas supply mechanism can be an air compressor 18. The gas supply mechanism is connected to the plasma generator 9 through an air inlet pipe 15. The air inlet pipe 15 is set to fit the straight waveguide 8, the bent waveguide 7, and the extended coupling section 13. The plasma generator 9 has multiple gas inlets 16, which form multiple tangential gas supply channels to tangentially introduce working gas into the plasma generator 9 to form a swirling stable field, so that the plasma column is radially away from the pipe wall and maintains axial stability, thereby improving discharge stability and reducing the risk of local ablation and fouling. The flow rate of the working gas and the ratio of the gas introduced into the multiple tangential gas supply channels are adjusted in real time by the control unit or linked with the boiler operation signal to adapt to the needs of ignition, stable combustion, and load change stages.

[0036] To achieve thermal management for high-power continuous operation, this equipment is equipped with cooling mechanisms for the all-solid-state microwave source 1, waveguide transmission components, and plasma generator 9. Specifically, a water-cooling mechanism 19 is selected. Independent cooling circuits are configured for the all-solid-state microwave source and key high-heat components. Existing annular jackets or spiral water-cooling structures are installed on the waveguide directional section, the extended coupling section 13, and the outer wall of the plasma generator 9 to reduce temperature rise and improve long-term operational stability. The cooling mechanism reduces the thermal load on key components, improving lifespan and safety margin under high-power continuous operation conditions. The real-time monitoring unit performs closed-loop monitoring of cooling water temperature, flow rate, pressure, and temperature of key components. When the cooling capacity is insufficient, the temperature exceeds the limit, or the water circuit is abnormal, the all-solid-state microwave source is triggered to reduce power / shutdown interlock, ensuring safe and reliable operation of the equipment under high-power conditions.

[0037] refer to Figure 4 and Figure 5 As shown, the plasma generator 9 includes an exciter 26, which is connected to a guide tube 25. The guide tube 25 is connected to a dielectric tube 21, which is a quartz tube. An air intake component 24 is arranged circumferentially at one end of the dielectric tube 21 near the guide tube 25. The air intake component 24 is an annular structure with multiple air inlets 16. The air intake component 24 is connected to the interior of the dielectric tube 21. The dielectric tube 21 is supported by a support base 11, which is connected to the interior of the dielectric tube. A plasma generating chamber 23 is formed at the connection between the dielectric tube 21 and the support base. A cooling component 22 is arranged circumferentially on both sides of the support base. The cooling component is specifically an annular jacket or a spiral water-cooling structure.

[0038] It should be explained that the working gas in the plasma generator 9 can be air, nitrogen, or an inert gas (such as argon), and can be selected or switched according to the boiler ignition and stable combustion requirements. When air is used as the working gas, the gas supply mechanism can be simplified and engineering applications can be facilitated. When an inert gas is used as the working gas, the discharge stability can be improved and the low-load ignition window can be expanded.

[0039] Compared with the magnetron microwave ignition device, the all-solid-state microwave source 1 provided in this embodiment has higher output controllability under frequent start-stop and load fluctuation conditions. Combined with closed-loop tuning of reflected power, it effectively reduces the probability of mismatch triggering protection shutdown. Compared with DC electrode plasma ignition, the equipment in this embodiment has an electrodeless structure, which effectively reduces electrode ablation and replacement maintenance workload, and is suitable for long-cycle operation scenarios.

[0040] In this embodiment, through the setting of the real-time monitoring unit, the control unit establishes interlocking control logic based on incident power, reflected power, etc. When the reflected power ratio exceeds the set value, the control unit prioritizes driving the automatic tuner to perform impedance matching; if the limit is still exceeded after matching, the output power of the all-solid-state microwave source is reduced; when the dual directional coupler 5 or the power meter detects that the reflected power continues to exceed the limit, the second temperature sensor detects that the temperature at the inlet pipe or outlet pipe of the cooling mechanism is too high, or the key parameters exceed the limit, the control unit triggers the safety interlock, links the all-solid-state microwave source to reduce the microwave output power or quickly shuts down the all-solid-state microwave source, while maintaining the cooling mechanism to protect the equipment and avoid the risk of backfire in the furnace.

[0041] Example 2 This embodiment provides a high-power all-solid-state microwave plasma torch pulverized coal boiler, referenced... Figure 4 As shown, an ignition port 20 is provided on the side wall of the boiler furnace. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment described in Embodiment 1 is installed through the opening. The distance between the plasma generator and the waveguide directional section in the ignition equipment is adapted to the height of the ignition port to facilitate entry into the boiler ignition port and easy exit after ignition. The all-solid-state microwave source is placed on the outside of the boiler furnace 10 through the ground. The torch head and the waveguide directional section pass through the ignition port 20 and are located inside the boiler furnace 10. Moreover, the ignition point 11 generated by the torch head is located on the central axis of the boiler furnace 10, realizing lateral deep ignition. With the tangential swirl gas supply, the stability and anti-airflow disturbance capability of the plasma torch are improved, and the risk of torch swaying and arc extinction is reduced. It is suitable for furnace dust and strong disturbance conditions. During the ignition and stable combustion stages, it can reduce or replace the consumption of ignition oil (gas), which helps to reduce emissions and operation and maintenance costs during start-up and shutdown.

[0042] Specifically, the waveguide transmission assembly is supported by support frame 12, as referenced. Figure 4 As shown, the support frame 12 includes two layers of horizontal supports, with vertical supports at the ends of the horizontal supports. The two vertical supports are spaced apart and connected to the horizontal supports. The top of the vertical supports supports the waveguide transmission assembly. The bottom horizontal supports are supported by the ground. The top of the vertical supports is provided with a support plate or directly supports the waveguide transmission assembly to ensure the stability of the structure.

[0043] Example 3 This embodiment provides an ignition method for a pulverized coal boiler, which uses the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment from Embodiment 1, including the following components: The all-solid-state microwave source is placed on the outside of the boiler furnace via the ground, the torch head and waveguide directional section pass through the ignition port 20 and are located inside the boiler furnace, and the outlet end of the plasma generator is set close to the ignition point. Turn on the water cooling system, start each cooling circuit, and confirm that the flow rate and temperature are normal. Turn on the air compressor in the air supply mechanism, adjust the air pressure to 0.5 MPa, start the tangential air supply, and select the appropriate air flow rate by adjusting the flow meter to establish a swirling stable field; Turn on the power of the all-solid-state microwave source, adjust the parameters, specify the output frequency and power, and set the temperature and reflected power thresholds. The power will be automatically cut off if the thresholds are exceeded. At the same time, the power and temperature will be monitored in real time through the real-time monitoring unit, and the real-time values ​​can be viewed through the control unit. The plasma generator is remotely activated, and impedance matching is achieved through an automatic tuner to form a stable horizontally oriented plasma torch and align it with the furnace ignition area. Ignition and stable combustion are carried out under the condition of air-powdered powder. After ignition, the microwave power is gradually reduced or the machine is shut down according to the furnace temperature and load requirements.

[0044] The incident / reflected power was recorded over time using a power meter to evaluate the matching stability; the reactor wall temperature and the characteristic temperature of the flare area were monitored using thermocouple / infrared thermometry or spectroscopy to evaluate the thermal management effect; and the applicability of the equipment to the project was comprehensively evaluated using indicators such as ignition time, stable combustion duration, number of start-ups and shutdowns, and maintenance intervals.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An all-solid-state microwave plasma torch pulverized coal boiler ignition equipment, characterized in that, The system includes an all-solid-state microwave source, which is connected to a plasma generator via a waveguide transmission component and a waveguide directional section. A torch head is installed at the end of the plasma generator, with the central axis of the torch head parallel to the main body of the waveguide transmission component. The torch head and part of the waveguide transmission component can pass through the boiler's ignition port. The torch head is located in the pulverized coal-air mixing zone of the boiler furnace to concentrate the high-temperature plasma energy in the pulverized coal-air mixing zone. Isolation and load absorption components and an automatic tuner are sequentially installed along the waveguide transmission component in the torch head. The automatic tuner is connected to the waveguide directional section so that the torch generated by the torch head is output along the radial direction of the boiler furnace. The all-solid-state microwave source, plasma generator, and waveguide transmission component are each individually connected to a control unit.

2. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to claim 1, characterized in that, The ignition point generated by the torch head is located on the central axis of the boiler furnace.

3. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to claim 1, characterized in that, The waveguide orientation section includes a straight waveguide and a bent waveguide, which are connected. The bent waveguide is bent at 90° and connected to an extended coupling section. The extended coupling section is connected to the plasma generator. The extended coupling section is used to make the plasma generator higher than the waveguide transmission component.

4. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to claim 1, characterized in that, The isolation and load absorption component is a conversion waveguide used to introduce reflected power into the water load for absorption in the event of reflected waves or abnormal mismatch; The automatic tuner employs an adjustable matching structure to dynamically adjust the waveguide equivalent impedance.

5. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to claim 1, characterized in that, It also includes a gas supply mechanism, which is connected to the control unit and the plasma generator. The plasma generator is provided with a tangential gas supply channel to tangentially introduce working gas into the plasma generator to form a swirling stable field.

6. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to claim 1, characterized in that, It also includes a cooling mechanism, which includes a cooling circuit located at the all-solid-state microwave source, and a water-cooling structure located on the waveguide directional section and the outer wall of the plasma generator.

7. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment according to claim 6, characterized in that, It also includes a real-time monitoring unit, which includes a first temperature sensor located on the side wall of the plasma generator, a second temperature sensor, a flow sensor, and a pressure sensor located at the water inlet and water outlet pipes of the cooling mechanism, and each sensor is connected to the control unit. The real-time monitoring unit also includes a power meter or a dual-directional coupler, which is connected to the control unit and between the automatic tuner and the isolation and load absorption components. The power meter or dual-directional coupler collects the incident / reflected power in real time and sends the collected incident / reflected power to the control unit. The control unit compares the collected incident / reflected power with a set threshold. When the control unit determines that the reflected power deviates from the set threshold, the real-time monitoring unit drives the automatic tuner to perform optimization matching, thereby reducing the reflected power.

8. A pulverized coal boiler, characterized in that, An ignition port is provided on the side wall of the boiler furnace. The all-solid-state microwave plasma torch pulverized coal boiler ignition equipment as described in any one of claims 1-7 is installed through the ignition port. The distance between the plasma generator and the waveguide directional section in the ignition equipment is adapted to the height of the ignition port. The all-solid-state microwave source is placed outside the boiler furnace through the ground. The torch head and the waveguide directional section pass through the ignition port and are located inside the boiler furnace.

9. A high-power all-solid-state microwave plasma torch pulverized coal boiler according to claim 8, characterized in that, The waveguide transmission component is supported by a support frame.

10. An ignition method for a pulverized coal boiler, employing the all-solid-state microwave plasma torch pulverized coal boiler ignition equipment as described in any one of claims 1-7, characterized in that, Includes the following: The all-solid-state microwave source is placed on the outside of the boiler furnace via the ground, the torch head and waveguide directional section pass through the ignition port and are located inside the boiler furnace, and the outlet end of the plasma generator is set close to the ignition point. Turn on the all-solid-state microwave source, the load absorption component in the waveguide transmission assembly, the dual directional coupler and the automatic tuner. The all-solid-state microwave source serves as the energy input end, outputting continuous wave microwave power that can be adjusted within a preset range. The microwave energy is coupled to the plasma generator through the waveguide transmission assembly. The plasma generator is turned on to stimulate the plasma, and impedance matching is achieved through the automatic tuner to form a stable horizontal directional plasma torch and align it with the ignition area of ​​the boiler furnace. Ignition and stable combustion are carried out under the condition of air-assisted coal feeding. After ignition, the power of the all-solid-state microwave source is gradually reduced or shut down according to the boiler furnace temperature and load requirements.

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