Biomass powder ignition stable combustion device and method for coal-fired power plant boiler

Abstract

The invention provides a biomass powder ignition stable combustion device and method for a coal-fired power plant boiler. A biomass powder ignition stable combustion device for a coal-fired power plant boiler comprises a barrel used for conveying biomass powder airflow, a high-energy igniter, an inner barrel used for conveying combustion-supporting hot air and a concentration cone section used for enabling the biomass powder airflow to generate a gas-solid separation phenomenon, and the inner barrel and the concentration cone section are both fixedly installed in the barrel. Gaps are formed between the barrel and the inner barrel and between the high-energy igniter and the inner barrel, the concentration cone section is adjacent to one end of the barrel, and the high-energy igniter is installed in the inner barrel in a sliding mode. And biomass is adopted as an ignition stable combustion medium, so that the carbon emission of the unit can be reduced, and the cost is low. The biomass powder ignition stable combustion device can continuously and economically operate under the lowest stable combustion load and continuously and economically operate in parallel with the main combustor under the full load so as to increase the peak capacity of the unit, and the lowest stable combustion load is put into operation at the rising load stage so as to increase the variable load rate of the unit, so that the flexibility of the unit is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ignition and combustion stabilization devices for coal-fired power station boilers, and in particular to a biomass powder ignition and combustion stabilization device and method for coal-fired power station boilers. Background Art

[0002] Related goals promote the transition of coal-fired power generation towards low-carbon and flexible operation, requiring coal-fired power units to frequently participate in deep peak-shaving operations and even increase the number of starts and stops. During startup ignition and low-load stabilization, coal-fired power units consume significant amounts of fuel oil or electricity, reducing unit economics and increasing carbon emissions. Considering the high volatility, excellent ignition characteristics, and unit price per kilowatt-hour of renewable energy, biomass powder is a viable option for igniting and stabilizing the pulverized coal flow in power plant boiler burners. This approach offers low operating costs and is environmentally friendly and low-carbon.

[0003] Biomass, a renewable energy source, produces virtually no carbon emissions during combustion and power generation. Therefore, incorporating biomass into coal-fired power plants not only significantly reduces carbon emissions but also represents a key path to low-carbon transformation in the thermal power industry. Extensive research and application of biomass integration into large coal-fired power plant boilers has been conducted abroad, with some units successfully operating on 100% biomass fuel. Some domestic power plants have also conducted biomass integration trials or retrofits, but at relatively low levels, and have established biomass supply systems around the power plants.

[0004] The above applications generally achieve biomass co-combustion by coupling the powder delivery pipeline, modifying the existing pulverized coal burner, adding a dedicated biomass burner, etc., but the ignition and combustion stabilization device of the original pulverized coal main burner still uses the original conventional ignition and combustion stabilization medium or electricity, and the internal structure and function of the original ignition and combustion stabilization device are not designed and modified in a targeted manner. The existing patent "CN118935372A" discloses a biomass direct co-combustion combustion device for a tangentially tangentially coal-fired boiler, "CN220689059U" discloses a biomass burner for a coal-fired boiler, and "CN117091135A" discloses a three-purpose burner for biomass powder, oil, and gas. The above existing patents only involve functional improvements to the boiler main burner to achieve co-combustion of biomass, and do not involve improvements to the burner ignition scheme.

[0005] Existing large-scale coal-fired power plant boilers generally use conventional large oil guns, micro-oil ignition devices, or plasma ignition devices for startup ignition or low-load stable combustion. Conventional large oil guns or micro-oil ignition devices both use fuel oil as the ignition and stable combustion medium. The former uses a high-energy igniter to ignite a large amount of atomized oil droplets and then ignite the coal powder airflow outside the device. The latter is generally inserted into the main burner and uses a small amount of ignited fuel oil flame to ignite the coal powder airflow inside the main burner. Plasma ignition and stable combustion devices use a plasma generator inserted into the main burner to form a high-temperature arc and ignite the coal powder airflow inside the main burner. The plasma ignition and stable combustion device uses a plasma generator inserted into the main burner to form a high-temperature arc and ignite the coal powder airflow inside the main burner, and gradually expands the combustion to sufficient thermal power to ignite the coal powder airflow outside the device. The above ignition and stable combustion methods all use fuel oil or a high-temperature arc as a medium to ignite or stabilize the coal powder airflow outside the ignition device.

[0006] Existing ignition and combustion stabilization systems for coal-fired power plant boilers primarily use fuel oil or electricity as a medium to provide a high-temperature heat source to the pulverized coal stream during startup or low-load conditions. The former consumes expensive fossil energy, while the latter converts high-quality coal into thermal energy. Both systems have the disadvantages of high costs and carbon emissions. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a biomass powder ignition and stabilization combustion device and method for coal-fired power station boilers in response to the deficiencies of the existing technology.

[0008] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A biomass powder ignition and stabilization combustion device for a coal-fired power station boiler comprises: a cylinder for conveying a biomass powder airflow, a high-energy igniter, an inner cylinder for conveying combustion-supporting hot air, and a concentrating cone section for causing the biomass powder airflow to produce a gas-solid separation phenomenon. The inner cylinder and the concentrating cone section are both fixedly installed in the cylinder, and there are gaps between the cylinder and the inner cylinder and between the high-energy igniter and the inner cylinder. The concentrating cone section is adjacent to one end of the cylinder, and the high-energy igniter is slidably installed in the inner cylinder.

[0009] The beneficial effects of the technical solution of the present invention are as follows: the biomass powder airflow enters the cylinder and flows, where it is affected by the concentrating cone to produce a gas-solid separation phenomenon: due to its large inertia, the biomass powder particles concentrate toward the center of one end of the cylinder, while the airflow flows approximately evenly at that end. As a result, the biomass powder airflow forms a dense phase of biomass powder at the end of the high-energy igniter, which is conducive to ignition and stable combustion. The combustion-supporting hot air enters the inner cylinder and flows inside. By heating the inner cylinder, it preheats the outer biomass powder airflow to reduce the difficulty of ignition and provides a heat source and oxidant for the dense phase of biomass powder at the end of the high-energy igniter. The dense phase of biomass powder near the end of the high-energy igniter mixes with the combustion-supporting hot air from the inner cylinder and rapidly precipitates volatiles. During the ignition phase, the end of the extended high-energy igniter generates a high-temperature arc and ignites the volatiles, ultimately forming a stable flame. Using biomass as the ignition and stable combustion medium can effectively reduce the unit's carbon emissions and is relatively low in cost. The ignition and stabilization combustion device using biomass powder can operate continuously and economically at the lowest stable combustion load, operate continuously and economically in parallel with the main burner at full load to increase the peak capacity of the unit, and increase the unit's variable load rate when put into operation in the rising load stage at the lowest stable combustion load, thereby improving the unit's flexibility.

[0010] Furthermore, an inlet for inputting biomass powder airflow is provided on the side wall of the cylinder, an outlet for outputting biomass powder airflow is provided at one end of the cylinder, an inlet for inputting combustion-supporting hot air is provided at the other end of the inner cylinder, and an outlet for outputting combustion-supporting hot air is provided at one end of the inner cylinder; the inner cylinder is coaxially arranged with the cylinder.

[0011] The beneficial effects of this further technical solution are as follows: combustion-supporting hot air is introduced into the inner barrel to provide ignition heat and oxidant. The combustion-supporting hot air can be connected to the boiler's primary or secondary air mains. As it flows within the inner barrel, the combustion-supporting hot air preheats the external biomass powder airflow, reducing ignition time. The biomass powder airflow enters the barrel at the inlet, turns, and flows toward the outlet. The concentrating cone acts to produce gas-solid separation: Due to its large inertia, the biomass powder particles concentrate toward the center of the barrel's outlet, while the airflow maintains a nearly uniform flow across the outlet cross-section. This results in a dense phase of biomass powder at the end of the high-energy igniter, which facilitates stable ignition. The combustion-supporting hot air enters the inner barrel and flows toward the outlet. By heating the inner barrel, it preheats the external biomass powder flow, reducing ignition difficulty and providing a heat source and oxidant for the dense phase of biomass powder at the device outlet. The dense phase of biomass powder near the end of the high-energy igniter at the device outlet mixes with the combustion-supporting hot air at the inner barrel outlet, rapidly releasing volatiles.

[0012] Furthermore, the inlet of the inner tube is connected to the boiler hot primary air or hot secondary air main pipe.

[0013] The beneficial effect of adopting the above further technical solution is: the combustion-supporting hot air is introduced into the inner tube to provide an ignition heat source and an oxidant, and the combustion-supporting hot air can be connected to the boiler hot primary air or hot secondary air main pipe.

[0014] Furthermore, a conical cavity is provided in the concentrating cone section, an end of the concentrating cone section with a smaller opening faces one end of the cylinder, and an end of the concentrating cone section with a larger opening faces the other end of the cylinder.

[0015] The beneficial effect of adopting the above-mentioned further technical solution is that the biomass powder airflow enters the cylinder from the inlet of the cylinder, turns and flows toward the outlet of the cylinder, and produces a gas-solid separation phenomenon under the action of the concentration cone section: the biomass powder particles are concentrated toward the center of the outlet of the cylinder due to their large inertia, and the airflow flows approximately uniformly on the outlet cross-section of the cylinder, so the biomass powder flow forms a biomass powder dense phase at the end of the high-energy igniter, which is conducive to ignition and stable combustion.

[0016] Furthermore, a flame stabilizing fixture for stabilizing combustion is fixedly mounted on one end of the cylinder, one end of the inner cylinder is fixedly connected to the flame stabilizing fixture, and the flame stabilizing fixture is a cross-shaped structure.

[0017] The beneficial effect of adopting this further technical solution is that the flame-stabilizing fixture is heated by the flame to form a high-temperature component, which has a certain heat storage and heat transfer capacity, which helps stabilize the biomass powder and achieve stable combustion. The flame-stabilizing fixture has a cross-shaped structure, which facilitates the output of the biomass powder airflow at one end of the cylinder.

[0018] Furthermore, the high-energy igniter is connected to a high-energy igniter telescopic mechanism, and the high-energy igniter telescopic mechanism is installed at the other end of the cylinder.

[0019] The beneficial effects of adopting the above-mentioned further technical solution are: during the ignition stage, the end of the extended high-energy igniter generates a high-temperature arc and ignites the volatile matter, eventually forming a stable flame; after the ignition is completed, the high-energy igniter retreats to the inside of the cylinder under the action of the high-energy igniter telescopic mechanism, away from the center of the flame and protected by the combustion-supporting air to prevent backfire and burning.

[0020] Furthermore, a mounting portion is installed on the outer side wall of the cylinder.

[0021] The beneficial effect of adopting the above-mentioned further technical solution is that the biomass powder ignition and combustion stabilization device for coal-fired power station boiler is conveniently fixed through the mounting part to the original installation position of the micro-oil ignition or plasma ignition and combustion stabilization device of the bottom burner of the boiler or the original installation position of the large oil gun ignition and combustion stabilization device of other layers of burner.

[0022] Furthermore, the low calorific value of the biomass powder is not less than 3000 kCal / kg, the moisture content of the biomass powder is not more than 20%, and the average particle size of the biomass is not more than 0.3 mm.

[0023] The beneficial effect of adopting the above-mentioned further technical solution is: by restricting the quality indicators of biomass powder, the ignition performance of biomass powder is enhanced, and the ignition and stable combustion effects are guaranteed.

[0024] In addition, the present invention also provides a method for igniting and stabilizing combustion of biomass powder for coal-fired power station boilers. Based on the above-mentioned device for igniting and stabilizing combustion of biomass powder for coal-fired power station boilers, the method for igniting and stabilizing combustion of biomass powder for coal-fired power station boilers includes: S1, introducing a biomass powder airflow into the cylinder, and introducing combustion-supporting hot air into the inner cylinder; S2, causing the biomass powder airflow to produce gas-solid separation through the conical section, so that the biomass powder airflow device forms a biomass powder near the end of the high-energy igniter that is conducive to ignition and stable combustion. The inner cylinder is heated by the combustion-supporting hot air, and the biomass powder airflow outside the inner cylinder is preheated to reduce the difficulty of ignition, and provide a heat source and oxidant for the dense phase biomass powder at one end of the cylinder; S3, the dense phase biomass powder near the end of the high-energy igniter is mixed with the combustion-supporting hot air to precipitate volatile matter; S4, the high-energy igniter is slided so that the high-energy igniter extends out of one end of the cylinder, and the volatile matter is ignited by the high-energy igniter to form a stable flame; S5, the high-energy igniter is slided so that the high-energy igniter is retracted to the inside of the cylinder.

[0025] The beneficial effects of the technical solution of the present invention are as follows: the biomass powder airflow enters the cylinder and flows, where it is affected by the concentrating cone to produce a gas-solid separation phenomenon: due to its large inertia, the biomass powder particles concentrate toward the center of one end of the cylinder, while the airflow flows approximately evenly at that end. As a result, the biomass powder airflow forms a dense phase of biomass powder at the end of the high-energy igniter, which is conducive to ignition and stable combustion. The combustion-supporting hot air enters the inner cylinder and flows inside. By heating the inner cylinder, it preheats the outer biomass powder airflow to reduce the difficulty of ignition and provides a heat source and oxidant for the dense phase of biomass powder at the end of the high-energy igniter. The dense phase of biomass powder near the end of the high-energy igniter mixes with the combustion-supporting hot air from the inner cylinder and rapidly precipitates volatiles. During the ignition phase, the end of the extended high-energy igniter generates a high-temperature arc and ignites the volatiles, ultimately forming a stable flame. Using biomass as the ignition and stable combustion medium can effectively reduce the unit's carbon emissions and is relatively low in cost. The ignition and stabilization combustion device using biomass powder can operate continuously and economically at the lowest stable combustion load, operate continuously and economically in parallel with the main burner at full load to increase the peak capacity of the unit, and increase the unit's variable load rate when put into operation in the rising load stage at the lowest stable combustion load, thereby improving the unit's flexibility.

[0026] Furthermore, in step S4 and step S5, the high-energy igniter is slid through the high-energy igniter telescopic mechanism; in step S4, a high-temperature arc is generated by the high-energy igniter to ignite volatile matter, and the heat storage and heat transfer capacity of the flame stabilizing fixture is used to promote the stability of the biomass powder.

[0027] The beneficial effects of this further technical solution include: the high-energy igniter is slidable via its retractable mechanism, improving automation and facilitating its extension and retraction. The heat storage and heat transfer capabilities of the flame stabilizing fixture promote biomass powder stability. The flame stabilizing fixture, heated by the flame to form a high-temperature component, possesses a certain heat storage and heat transfer capacity that contributes to biomass powder stability and achieves stable combustion.

[0028] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of a biomass powder ignition and combustion stabilization device for a coal-fired power station boiler provided by an embodiment of the present invention.

[0030] Figure 2 for Figure 1 Side view of the structure shown.

[0031] Figure 3 A schematic flow chart of a method for igniting and stabilizing biomass powder in a coal-fired power station boiler provided in an embodiment of the present invention.

[0032] Explanation of the accompanying figures: 1. Cylinder; 2. High-energy igniter; 3. High-energy igniter telescopic mechanism; 4. Flame stabilizing fixing device; 5. Inner cylinder; 6. Concentrating cone section; 7. Mounting part. DETAILED DESCRIPTION

[0033] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0034] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a biomass powder ignition and stabilization combustion device for a coal-fired power station boiler, comprising: a cylinder 1 for conveying a biomass powder airflow, a high-energy igniter 2, an inner cylinder 5 for conveying combustion-supporting hot air, and a concentrating cone section 6 for causing the biomass powder airflow to produce a gas-solid separation phenomenon. The inner cylinder 5 and the concentrating cone section 6 are both fixedly installed in the cylinder 1, and there are gaps between the cylinder 1 and the inner cylinder 5, and between the high-energy igniter 2 and the inner cylinder 5. The concentrating cone section 6 is adjacent to one end of the cylinder 1, and the high-energy igniter 2 is slidably installed in the inner cylinder 5.

[0035] The beneficial effects of the technical solution of the present invention are as follows: the biomass powder airflow enters the cylinder and flows, where it is affected by the concentrating cone to produce a gas-solid separation phenomenon: due to its large inertia, the biomass powder particles concentrate toward the center of one end of the cylinder, while the airflow flows approximately evenly at that end. As a result, the biomass powder airflow forms a dense phase of biomass powder at the end of the high-energy igniter, which is conducive to ignition and stable combustion. The combustion-supporting hot air enters the inner cylinder and flows inside. By heating the inner cylinder, it preheats the outer biomass powder airflow to reduce the difficulty of ignition and provides a heat source and oxidant for the dense phase of biomass powder at the end of the high-energy igniter. The dense phase of biomass powder near the end of the high-energy igniter mixes with the combustion-supporting hot air from the inner cylinder and rapidly precipitates volatiles. During the ignition phase, the end of the extended high-energy igniter generates a high-temperature arc and ignites the volatiles, ultimately forming a stable flame. Using biomass as the ignition and stable combustion medium can effectively reduce the unit's carbon emissions and is relatively low in cost. The ignition and stabilization combustion device using biomass powder can operate continuously and economically at the lowest stable combustion load, operate continuously and economically in parallel with the main burner at full load to increase the peak capacity of the unit, and increase the unit's variable load rate when put into operation in the rising load stage at the lowest stable combustion load, thereby improving the unit's flexibility.

[0036] Existing ignition and combustion stabilization devices for coal-fired power plant boilers primarily use fuel oil or electricity as a medium to provide a high-temperature heat source to the pulverized coal flow during startup or low-load conditions. The former consumes expensive fossil fuels, while the latter converts high-grade coal into thermal energy. Both are associated with high costs and carbon emissions. Due to the high cost of these media, coal-fired power plants only operate ignition and combustion stabilization devices when they meet the safety requirements of startup ignition and low-load stable combustion. This restricts unit operation to below the minimum stable combustion load and at peak load, limiting the unit's flexibility.

[0037] In recent years, with the widespread adoption of direct-combustion biomass in coal-fired power plants, some coal-fired power plants have fostered a surrounding biomass supply market and established a unit-calorie biomass price equivalent to or lower than that of thermal coal. When measured by the total heat required for ignition and stable combustion, biomass offers significant price competitiveness compared to fuel oil or electricity. Biomass is a renewable energy source that produces virtually no carbon emissions during combustion, so using biomass as an ignition and stable combustion medium can effectively reduce the unit's carbon emissions. Furthermore, a new ignition and stable combustion device using biomass powder (for coal-fired power plant boilers) can operate continuously and economically at the lowest stable combustion load, operate continuously and economically in parallel with the main burner at full load to increase the unit's peak capacity, and increase the unit's variable load rate when put into operation during the rising load phase at the lowest stable combustion load, thereby improving the unit's flexibility.

[0038] In response to the shortcomings of existing technologies such as high operating costs and high carbon emission intensity, an embodiment of the present invention provides a biomass powder ignition and combustion stabilization device for coal-fired power station boilers. It can be a new type of ignition and combustion stabilization device that uses biomass as an energy carrier, is low-carbon, economical, and flexible in operation.

[0039] (1) In the embodiment of the present invention, biomass powder is used as the ignition and combustion stabilization medium (energy carrier).

[0040] (2) The embodiment of the present invention has the following combined structural features or combined technologies to ensure the realization of the ignition and stable combustion functions: a concentration cone section 6 is provided to form a dense phase of biomass powder at the center of the device outlet to reduce the difficulty of ignition, the inner cylinder 5 introduces combustion-supporting hot air to provide an ignition heat source and oxidant, the combustion-supporting hot air preheats the external biomass powder airflow to reduce the ignition time, and a flame stabilizing fixing device 4 is provided for stable combustion.

[0041] (3) The embodiments of the present invention put forward the following requirements for biomass powder used for ignition and stable combustion: the low calorific value of biomass powder should not be lower than 3000kCal / kg (preferably 3500kCal / kg), the moisture content should not exceed 20% (preferably 10%), and the average particle size of biomass should not exceed 0.3mm (preferably 0.1mm).

[0042] (4) In addition to being applied to the start-up ignition and low-load stable combustion of pulverized coal boilers, the embodiments of the present invention can be used to operate in parallel with pulverized coal burners at full load to increase the boiler's thermal power output, thereby improving the unit's peak capacity.

[0043] The embodiment of the present invention utilizes renewable energy biomass to replace fuel oil and coal-fired power as an ignition and combustion stabilization medium, generates almost no carbon emissions during use, and can reduce carbon emissions during the startup of pulverized coal boilers and low-load stable combustion.

[0044] In addition to the characteristics of biomass such as high volatile matter content and low ignition temperature, the embodiments of the present invention adopt a series of combined technologies and restrict biomass powder quality indicators to enhance the ignition performance of biomass powder. The embodiments of the present invention can achieve good ignition and stable combustion effects.

[0045] This embodiment of the present invention uses biomass, whose unit calorific value is similar to that of thermal coal, as an ignition and combustion medium, improving the ignition and combustion economy during unit startup and low-load stable combustion. This embodiment of the present invention can operate continuously below the boiler's minimum stable combustion load and at peak full load, expanding the unit's peak load regulation range. Furthermore, this embodiment of the present invention can be put into operation during load ramp-up phases above the unit's minimum stable combustion load, accelerating the unit's load change rate. Therefore, this embodiment of the present invention improves the unit's peak load regulation flexibility.

[0046] like Figure 1 and Figure 2 As shown, further, an inlet for inputting biomass powder airflow is provided on the side wall of the cylinder 1, an outlet for outputting biomass powder airflow is provided at one end of the cylinder 1, an inlet for inputting combustion-supporting hot air is provided at the other end of the inner cylinder 5, and an outlet for outputting combustion-supporting hot air is provided at one end of the inner cylinder 5; the inner cylinder 5 is coaxially arranged with the cylinder 1.

[0047] The beneficial effects of this further technical solution are as follows: combustion-supporting hot air is introduced into the inner barrel to provide ignition heat and oxidant. The combustion-supporting hot air can be connected to the boiler's primary or secondary air mains. As it flows within the inner barrel, the combustion-supporting hot air preheats the external biomass powder airflow, reducing ignition time. The biomass powder airflow enters the barrel at the inlet, turns, and flows toward the outlet. The concentrating cone acts to produce gas-solid separation: Due to its large inertia, the biomass powder particles concentrate toward the center of the barrel's outlet, while the airflow maintains a nearly uniform flow across the outlet cross-section. This results in a dense phase of biomass powder at the end of the high-energy igniter, which facilitates stable ignition. The combustion-supporting hot air enters the inner barrel and flows toward the outlet. By heating the inner barrel, it preheats the external biomass powder flow, reducing ignition difficulty and providing a heat source and oxidant for the dense phase of biomass powder at the device outlet. The dense phase of biomass powder near the end of the high-energy igniter at the device outlet mixes with the combustion-supporting hot air at the inner barrel outlet, rapidly releasing volatiles.

[0048] The high-energy igniter 2 and the inner cylinder 5 can be coaxially arranged to facilitate uniform dispersion of the combustion-supporting hot air.

[0049] Furthermore, the inlet of the inner tube 5 is connected to the boiler hot primary air or hot secondary air main pipe.

[0050] The beneficial effect of adopting the above further technical solution is: the combustion-supporting hot air is introduced into the inner tube to provide an ignition heat source and an oxidant, and the combustion-supporting hot air can be connected to the boiler hot primary air or hot secondary air main pipe.

[0051] like Figure 1 and Figure 2 As shown, further, a conical cavity is provided in the concentrating cone section 6 , the end of the concentrating cone section 6 with a smaller opening faces one end of the cylinder 1 , and the end of the concentrating cone section 6 with a larger opening faces the other end of the cylinder 1 .

[0052] The beneficial effect of adopting the above-mentioned further technical solution is that the biomass powder airflow enters the cylinder from the inlet of the cylinder, turns and flows toward the outlet of the cylinder, and produces a gas-solid separation phenomenon under the action of the concentration cone section: the biomass powder particles are concentrated toward the center of the outlet of the cylinder due to their large inertia, and the airflow flows approximately uniformly on the outlet cross-section of the cylinder, so the biomass powder flow forms a biomass powder dense phase at the end of the high-energy igniter, which is conducive to ignition and stable combustion.

[0053] like Figure 1 and Figure 2 As shown, further, a flame stabilizing fixture 4 for stabilizing combustion is fixedly installed at one end of the cylinder 1, and one end of the inner cylinder 5 is fixedly connected to the flame stabilizing fixture 4, and the flame stabilizing fixture 4 is a cross-shaped structure.

[0054] The beneficial effect of adopting this further technical solution is that the flame-stabilizing fixture is heated by the flame to form a high-temperature component, which has a certain heat storage and heat transfer capacity, which helps stabilize the biomass powder and achieve stable combustion. The flame-stabilizing fixture has a cross-shaped structure, which facilitates the output of the biomass powder airflow at one end of the cylinder.

[0055] A through hole is provided in the middle of the flame stabilizing fixing device 4 , and one end of the inner cylinder 5 is installed in the through hole of the flame stabilizing fixing device 4 .

[0056] like Figure 1 and Figure 2 As shown, further, the high-energy igniter 2 is connected to a high-energy igniter telescopic mechanism 3, and the high-energy igniter telescopic mechanism 3 is installed at the other end of the cylinder 1.

[0057] The beneficial effects of adopting the above-mentioned further technical solution are: during the ignition stage, the end of the extended high-energy igniter generates a high-temperature arc and ignites the volatile matter, eventually forming a stable flame; after the ignition is completed, the high-energy igniter retreats to the inside of the cylinder under the action of the high-energy igniter telescopic mechanism, away from the center of the flame and protected by the combustion-supporting air to prevent backfire and burning.

[0058] The high-energy igniter telescopic mechanism 3 includes but is not limited to an electric push rod, a hydraulic cylinder or a pneumatic cylinder with a telescopic function.

[0059] like Figure 1 and Figure 2 As shown, further, a mounting portion 7 is installed on the outer side wall of the cylinder 1.

[0060] The beneficial effect of adopting the above-mentioned further technical solution is that the biomass powder ignition and combustion stabilization device for coal-fired power station boiler is conveniently fixed through the mounting part to the original installation position of the micro-oil ignition or plasma ignition and combustion stabilization device of the bottom burner of the boiler or the original installation position of the large oil gun ignition and combustion stabilization device of other layers of burner.

[0061] The mounting portion 7 may be a flange, which is provided with a mounting hole, and a fixing bolt is installed in the mounting hole.

[0062] Furthermore, the low calorific value of the biomass powder is not less than 3000 kCal / kg, the moisture content of the biomass powder is not more than 20%, and the average particle size of the biomass is not more than 0.3 mm.

[0063] The beneficial effect of adopting the above-mentioned further technical solution is: by restricting the quality indicators of biomass powder, the ignition performance of biomass powder is enhanced, and the ignition and stable combustion effects are guaranteed.

[0064] The biomass powder ignition and combustion stabilization device for a coal-fired power station boiler provided in an embodiment of the present invention can be an ignition and combustion stabilization device, including: a cylinder 1, a high-energy igniter 2, a high-energy igniter telescopic mechanism 3, a flame stabilization fixing device 4, an inner cylinder 5, a concentration cone section 6 and a mounting portion 7.

[0065] The biomass powder airflow enters the cylinder 1 from the inlet of the cylinder 1, turns and flows toward the outlet of the cylinder 1, and is affected by the concentration cone section 6 to produce gas-solid separation phenomenon: due to the large inertia, the biomass powder particles are concentrated toward the center of the outlet of the cylinder 1 (that is, the end of the high-energy igniter 2), and the airflow flows approximately uniformly on the outlet cross-section of the cylinder 1. Therefore, the biomass powder flow (biomass powder airflow) forms a biomass powder dense phase at the end of the high-energy igniter 2, which is conducive to ignition and stable combustion.

[0066] The combustion-supporting hot air enters the inner tube 5 and flows toward the outlet. By heating the inner tube 5, the outer biomass powder flow can be preheated to reduce the difficulty of ignition, and provide a heat source and oxidant for the dense phase biomass powder at the outlet of the device (a biomass powder ignition and stabilization device for coal-fired power station boilers).

[0067] Dense biomass powder near the end of the high-energy igniter 2 at the outlet of the device (a biomass powder ignition and stabilization device for coal-fired power plant boilers) mixes with the combustion-supporting hot air from the outlet of the inner cylinder 5, rapidly releasing volatiles. During the ignition phase, the extended end of the high-energy igniter 2 generates a high-temperature arc, igniting the volatiles and ultimately forming a stable flame. After ignition is complete, the high-energy igniter 2, guided by the high-energy igniter retraction mechanism 3, retracts into the interior of the cylinder 1, away from the center of the flame and protected by the combustion-supporting air to prevent flashback and burns.

[0068] The device (a biomass powder ignition and stabilization device for coal-fired power station boilers) is fixed via the mounting portion 7 to the original mounting position of the micro-oil ignition or plasma ignition and stabilization device of the bottom burner of the boiler or the original mounting position of the large oil gun ignition and stabilization device of other burners.

[0069] In order to ensure the ignition and stable combustion effects, the embodiments of the present invention require that: (1) the low calorific value of biomass powder should not be lower than 3000 kCal / kg (preferably 3500 kCal / kg), the moisture content should not exceed 20% (preferably 10%), and the average particle size of biomass should not exceed 0.3 mm (preferably 0.1 mm); (2) the air-to-powder mass ratio of the inlet biomass powder airflow should not exceed 1:1.5 (preferably 1:2); (3) a concentrating cone section 6 is provided to make the biomass powder form a dense phase at the center of the device outlet to reduce the difficulty of ignition; (4) the inner tube 5 introduces combustion-supporting hot air to provide an ignition heat source and an oxidant, and the combustion-supporting hot air can be connected to the boiler hot primary air or hot secondary air main pipe; (5) the combustion-supporting hot air can preheat the external biomass powder airflow when flowing inside the inner tube 5 to reduce the ignition time; (6) the flame stabilizing fixing device 4 (cross-shaped) is heated by the flame to form a high-temperature component, and has a certain heat storage and heat transfer capacity, which is beneficial to the stability of the biomass powder.

[0070] like Figure 3 As shown, in addition, the present invention also provides a biomass powder ignition and stabilization method for coal-fired power station boilers. Based on the above-mentioned biomass powder ignition and stabilization device for coal-fired power station boilers, the biomass powder ignition and stabilization method for coal-fired power station boilers includes: S1, introducing biomass powder airflow into the cylinder, and introducing combustion-supporting hot air into the inner cylinder; S2, causing the biomass powder airflow to produce gas-solid separation through the conical section, so that the biomass powder airflow device forms a gas-solid separation near the end of the high-energy igniter that is conducive to ignition and stabilization. Dense phase of biomass powder; the inner cylinder is heated by combustion-supporting hot air, and the biomass powder airflow outside the inner cylinder is preheated to reduce the difficulty of ignition, and provide a heat source and oxidant for the dense phase biomass powder at one end of the cylinder; S3, the dense phase biomass powder near the end of the high-energy igniter is mixed with the combustion-supporting hot air to precipitate volatile matter; S4, the high-energy igniter is slided so that the high-energy igniter extends out of one end of the cylinder, and the volatile matter is ignited by the high-energy igniter to form a stable flame; S5, the high-energy igniter is slided so that the high-energy igniter is retracted to the inside of the cylinder.

[0071] The beneficial effects of the technical solution of the present invention are as follows: the biomass powder airflow enters the cylinder and flows, where it is affected by the concentrating cone to produce a gas-solid separation phenomenon: due to its large inertia, the biomass powder particles concentrate toward the center of one end of the cylinder, while the airflow flows approximately evenly at that end. As a result, the biomass powder airflow forms a dense phase of biomass powder at the end of the high-energy igniter, which is conducive to ignition and stable combustion. The combustion-supporting hot air enters the inner cylinder and flows inside. By heating the inner cylinder, it preheats the outer biomass powder airflow to reduce the difficulty of ignition and provides a heat source and oxidant for the dense phase of biomass powder at the end of the high-energy igniter. The dense phase of biomass powder near the end of the high-energy igniter mixes with the combustion-supporting hot air from the inner cylinder and rapidly precipitates volatiles. During the ignition phase, the end of the extended high-energy igniter generates a high-temperature arc and ignites the volatiles, ultimately forming a stable flame. Using biomass as the ignition and stable combustion medium can effectively reduce the unit's carbon emissions and is relatively low in cost. The ignition and stabilization combustion device using biomass powder can operate continuously and economically at the lowest stable combustion load, operate continuously and economically in parallel with the main burner at full load to increase the peak capacity of the unit, and increase the unit's variable load rate when put into operation in the rising load stage at the lowest stable combustion load, thereby improving the unit's flexibility.

[0072] Furthermore, in step S4 and step S5, the high-energy igniter is slid through the high-energy igniter telescopic mechanism; in step S4, a high-temperature arc is generated by the high-energy igniter to ignite volatile matter, and the heat storage and heat transfer capacity of the flame stabilizing fixture is used to promote the stability of the biomass powder.

[0073] The beneficial effects of this further technical solution include: the high-energy igniter is slidable via its retractable mechanism, improving automation and facilitating its extension and retraction. The heat storage and heat transfer capabilities of the flame stabilizing fixture promote biomass powder stability. The flame stabilizing fixture, heated by the flame to form a high-temperature component, possesses a certain heat storage and heat transfer capacity that contributes to biomass powder stability and achieves stable combustion.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A biomass powder ignition and combustion stabilization device for coal-fired power station boilers, characterized in that: include: A cylinder (1) for conveying a biomass powder airflow, a high-energy igniter (2), an inner cylinder (5) for conveying combustion-supporting hot air, and a concentrating cone section (6) for causing the biomass powder airflow to produce a gas-solid separation phenomenon, wherein the inner cylinder (5) and the concentrating cone section (6) are both fixedly installed in the cylinder (1), and there are gaps between the cylinder (1) and the inner cylinder (5) and between the high-energy igniter (2) and the inner cylinder (5), the concentrating cone section (6) is adjacent to one end of the cylinder (1), and the high-energy igniter (2) is slidably installed in the inner cylinder (5).

2. The biomass powder ignition and combustion stabilization device for a coal-fired power station boiler according to claim 1, characterized in that: An inlet for inputting a biomass powder airflow is provided on the side wall of the cylinder (1), an outlet for outputting a biomass powder airflow is provided at one end of the cylinder (1), an inlet for inputting a combustion-supporting hot air is provided at the other end of the inner cylinder (5), and an outlet for outputting a combustion-supporting hot air is provided at one end of the inner cylinder (5); the inner cylinder (5) is coaxially arranged with the cylinder (1).

3. The biomass powder ignition and combustion stabilization device for a coal-fired power station boiler according to claim 2, characterized in that: The inlet of the inner cylinder (5) is connected to the boiler hot primary air or hot secondary air main pipe.

4. The biomass powder ignition and combustion stabilization device for a coal-fired power station boiler according to claim 1, characterized in that: A conical cavity is provided in the conical section (6), the end of the conical section (6) with a smaller opening faces one end of the cylinder (1), and the end of the conical section (6) with a larger opening faces the other end of the cylinder (1).

5. The biomass powder ignition and combustion stabilization device for coal-fired power station boilers according to claim 1, characterized in that: A flame stabilizing fixture (4) for stabilizing combustion is fixedly mounted on one end of the cylinder (1), and one end of the inner cylinder (5) is fixedly connected to the flame stabilizing fixture (4), wherein the flame stabilizing fixture (4) is a cross-shaped structure.

6. The biomass powder ignition and combustion stabilization device for coal-fired power station boilers according to claim 1, characterized in that: The high-energy igniter (2) is connected to a high-energy igniter telescopic mechanism (3), and the high-energy igniter telescopic mechanism (3) is installed at the other end of the cylinder (1).

7. The biomass powder ignition and combustion stabilization device for a coal-fired power station boiler according to claim 1, characterized in that: A mounting portion (7) is mounted on the outer side wall of the cylinder (1).

8. A biomass powder ignition and combustion stabilization device for a coal-fired power station boiler according to any one of claims 1 to 7, characterized in that: The low calorific value of the biomass powder is not less than 3000kCal / kg, the moisture content of the biomass powder is not more than 20%, and the average particle size of the biomass is not more than 0.3mm.

9. A method for igniting and stabilizing the combustion of biomass powder for coal-fired power station boilers, characterized in that: Based on the biomass powder ignition and stabilization combustion device for a coal-fired power station boiler according to any one of claims 1 to 8, the biomass powder ignition and stabilization combustion method for a coal-fired power station boiler comprises: S1, introduce biomass powder airflow into the cylinder, and introduce combustion-supporting hot air into the inner cylinder; S2. The biomass powder airflow is subjected to gas-solid separation through the concentrating cone section, so that a dense phase of biomass powder is formed near the end of the high-energy igniter, which is conducive to ignition and stable combustion. The inner cylinder is heated by the combustion-supporting hot air, and the biomass powder airflow outside the inner cylinder is preheated to reduce the difficulty of ignition, and a heat source and oxidant are provided for the dense phase of biomass powder at one end of the cylinder. S3, the dense phase biomass powder near the end of the high-energy igniter is mixed with the combustion-supporting hot air to separate out volatile matter; S4. Slide the high-energy igniter so that it extends out of one end of the cylinder, and ignite the volatile matter through the high-energy igniter to form a stable flame; S5. Slide the high-energy igniter so that it returns to the inside of the cylinder.

10. The method for igniting and stabilizing combustion of biomass powder for coal-fired power station boilers according to claim 9, characterized in that: In step S4 and step S5, the high-energy igniter is slid through the high-energy igniter telescopic mechanism; in step S4, a high-temperature arc is generated by the high-energy igniter to ignite volatile matter, and the heat storage and heat transfer capacity of the flame stabilizing fixture promotes the stability of the biomass powder.

Images