Boiler powder feeding system for optimizing pressure distribution of air powder mixer

Abstract

The invention provides a boiler powder feeding system for optimizing pressure distribution of an air-powder mixer, which comprises a powder bin, a vertical pipe, the air-powder mixer, an air supply system, a measuring system and an automatic control system, the powder bin is communicated with the air-powder mixer through the vertical pipe, the powder bin is of a structure with a cone, the side wall of the cone is provided with a fluidizing air inlet, the vertical pipe is provided with a coal pulling air system, and the air supply system is provided with an air inlet. The wind-powder mixer is composed of a flow guide cylinder, a flow guide plate and a wind-shielding break angle, the wind-powder mixer is provided with a horizontal airflow inlet and a top powder inlet, the wind-shielding break angle is located on the lower portion of the top powder inlet, and the pressure distribution optimization area is located behind the wind-shielding break angle on the middle section of the wind-powder mixer; and the automatic control system is connected with the powder bin, the vertical pipe and an air supply system of the air-powder mixer. The vertical pipe powder blockage is effectively avoided, air and powder are prevented from being mixed unevenly, the pressure distribution uniformity of the middle section of the air and powder mixer is improved, the controllability and stability of the powder flow rate of an outlet of the air and powder mixer are improved, and the safety and reliability of boiler combustion are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of safe operation of boilers, and in particular relates to a boiler powder feeding system for optimizing the pressure distribution of an air-powder mixer. Background Art

[0002] The boiler pulverized coal feeding system is an indispensable component of modern coal-fired boilers. It is mainly used to transport pulverized coal (coal powder) to the boiler furnace or burner for combustion. With the widespread application of coal-fired power generation and industrial boilers, pulverized coal combustion technology has become the core part of boiler technology, and the design and optimization of the pulverized coal feeding system directly affects the boiler's combustion efficiency, environmental emissions, operational stability and economy.

[0003] The main function of the boiler pulverized coal feeding system is to deliver pulverized coal from the storage, pulverizing or storage system to the boiler combustion area by pneumatic conveying. This process is not just a simple conveying process, but an extremely complex process that requires precise control. The uniformity of pulverized coal distribution during combustion is crucial to combustion efficiency, furnace temperature distribution and emission control. When the boiler adjusts the load, the pulverized coal feeding amount needs to be adjusted dynamically. The pulverized coal feeding system must be able to respond quickly to load changes, adjust the pulverized coal delivery amount, and ensure the stability and efficiency of combustion. The particle characteristics, moisture content, calorific value, ash content, etc. of the pulverized coal will affect the conveying effect of the pulverized coal feeding system, so it is necessary to have a flexible adjustment function to adapt to changes in coal quality.

[0004] First, how to ensure the uniform transportation of pulverized coal and avoid problems such as blockage and wear during transportation is still a difficult point in the design. Secondly, since the pulverized coal transportation system needs to operate at high load for a long time, its stability and reliability are particularly important. The maintenance and maintenance of the equipment should be considered during the design to reduce system failures and extend the life of the equipment. The boiler system needs to have flexible load adjustment capabilities, especially when the load changes frequently, the pulverized coal feeding system should be able to respond quickly to ensure the combustion stability and thermal efficiency of the boiler. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a boiler powder feeding system for optimizing the pressure distribution of an air-powder mixer, which adjusts the quantity of powder to be fed to the boiler in real time to achieve uniform delivery, improves the controllability and stability of the powder flow rate at the outlet of the air-powder mixer, and enhances the safety and reliability of boiler combustion.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: a boiler powder feeding system for optimizing the pressure distribution of an air-powder mixer, comprising a powder bin, a riser, an air-powder mixer, an air supply system, and an automatic control system; the powder bin is connected to the air-powder mixer through the riser, and the air supply system is connected to the air-powder mixer; a measuring system is installed in the air-powder mixer for real-time monitoring of the pressure and temperature of each pipeline and internal equipment of the boiler powder feeding system; the automatic control system is respectively connected to the powder bin, the riser, the air-powder mixer, and the air supply system, the automatic control system monitors the operating status of the boiler in real time, and quantitatively adjusts the airflow of the powder bin, the riser, the air-powder mixer, and the air supply system according to the operating status of the boiler.

[0007] Furthermore, the aforementioned air-powder mixer includes: a powder inlet, a guide cylinder, and a wind shield angle. The guide cylinder is arranged at the bottom of the air-powder mixer on the side close to the air supply system, and the wind shield angle is arranged below the powder inlet. When the air supply system outputs airflow to the air-powder mixer, the uniformity of the pressure distribution of the air-powder mixer can be improved by changing the airflow direction through the guide cylinder and the wind shield angle.

[0008] Furthermore, the aforementioned air-powder mixer also includes a guide plate, which is arranged in the middle section of the air-powder mixer and parallel to the gas flow direction of the air inlet, and the circular through holes evenly distributed on the guide plate are used to improve the air flow velocity in the air-powder mixer.

[0009] Furthermore, the upper part of the powder inlet of the aforementioned air-powder mixer is connected to a square-to-circular pipe and a curved pipe in sequence, and the curved pipe is connected to the end section of the vertical pipe, so as to improve the controllability of the powder falling from the vertical pipe into the air-powder mixer.

[0010] Furthermore, the aforementioned measurement system includes a sensor P1 and a sensor P2, wherein the sensor P1 is arranged in the rear area of ​​the bend, and the sensor P2 is arranged in the rear area of ​​the windshield corner, and the sensor P1 and the sensor P2 are used to measure the pressure gradient of the corresponding setting area to realize dynamic optimization and adjustment of the powder feeding.

[0011] Furthermore, the aforementioned air supply system comprises: an air filter, an air dryer, an air compressor, and an air storage tank connected in sequence through a gas pipeline; the air filter is used as the input end of the air supply system; a pressure regulating valve is installed on the gas pipeline between the air compressor and the inlet of the air storage tank; a safety valve and a flow meter are installed in sequence after the outlet of the air storage tank; the output end of the flow meter serves as the output end of the air supply system;

[0012] The pressure regulating valve, the safety valve and the flow meter are respectively connected to an automatic control system, and the automatic control system realizes automatic control of the air system according to the monitoring values ​​of the regulating valve, the safety valve and the flow meter.

[0013] Furthermore, the aforementioned powder bin is a cone structure, and the side wall of the cone has a fluidizing air inlet for achieving self-regulation of the fluidity and uniformity of the powder.

[0014] Furthermore, the aforementioned riser has a coal extraction air system, which can avoid blockage when powder is transported into the riser.

[0015] Furthermore, the aforementioned automatic control system adopts a fuzzy control algorithm or a PID control algorithm to achieve optimal regulation of powder feed.

[0016] Furthermore, the aforementioned powder bin is provided with temperature, humidity, and pressure sensors connected to an automatic control system for real-time monitoring of the storage environment of the powder to ensure the quality of the powder.

[0017] Compared with the prior art, the beneficial technical effects of the present invention using the above technical solution are as follows:

[0018] The present invention effectively avoids the blockage of powder in the riser, prevents the uneven mixing of air and powder in the air-powder mixer, improves the uniformity of the pressure distribution in the middle section of the air-powder mixer, improves the controllability and stability of the powder flow rate at the outlet of the air-powder mixer, and enhances the safety and reliability of boiler combustion. The present invention can ensure the uniform transportation of coal powder, and avoid problems such as blockage and wear during transportation. When the coal powder transportation system needs to operate at high load for a long time, the present invention can improve stability and reliability, while reducing system failures and extending equipment life. In particular, the present invention can achieve rapid response of the powder feeding system in the case of frequent load changes to ensure the combustion stability and thermal efficiency of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a block diagram of a boiler powder feeding system for optimizing the pressure distribution of an air-powder mixer.

[0020] Figure 2 It is a structural diagram of the air-powder mixer of the present invention.

[0021] In the figure, 1-powder bin, 2-vertical pipe, 3-air-powder mixer, 4-air supply system, 5-air filter, 6-air dryer, 7-air compressor, 8-pressure regulating valve, 9-air storage tank, 10-safety valve, 11-flow meter, 12-guide cylinder, 13-wind shield angle, 14-guide plate, 15-powder inlet, 16-square to circular pipe, 17-elbow pipe. DETAILED DESCRIPTION

[0022] In order to better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0023] Various aspects of the invention are described herein with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the invention are not limited to those described in the accompanying drawings. It should be understood that the invention is implemented by any of the various concepts and embodiments described above, as well as the concepts and embodiments described in detail below, because the concepts and embodiments disclosed in the invention are not limited to any implementation. In addition, some aspects disclosed in the invention may be used alone or in any appropriate combination with other aspects disclosed in the invention.

[0024] refer to Figure 1 and Figure 2 The present invention provides a boiler powder feeding system for optimizing the pressure distribution of an air-powder mixer, comprising: a powder bin 1, a riser 2, an air-powder mixer 3, an air supply system 4, and an automatic control system; the powder bin 1 is connected to the air-powder mixer 3 through the riser 2, and the air supply system 4 is connected to the air-powder mixer 3; a measuring system is installed in the air-powder mixer 3 for real-time monitoring of the pressure and temperature of each pipeline and internal equipment of the boiler powder feeding system; the automatic control system is respectively connected to the powder bin 1, the riser 2, the air-powder mixer 3, and the air supply system 4, the automatic control system monitors the operating status of the boiler in real time, and quantitatively adjusts the airflow of the powder bin 1, the riser 2, the air-powder mixer 3, and the air supply system 4 according to the operating status of the boiler.

[0025] like Figure 2 As shown, the pressure sensors P1 and P2 of the measuring system are located in the area behind the bend 17 and the windshield corner 13, and measure the pressure gradient in this area to achieve dynamic optimization adjustment of the powder feeding.

[0026] The powder bin 1 is a cone-shaped structure, and the side wall of the cone has a fluidizing air inlet. It is also provided with temperature, humidity and pressure sensors for real-time monitoring of the storage environment of the powder, ensuring the quality of the powder, and realizing self-regulation of the fluidity and uniformity of the powder. The riser 2 has a coal extraction air system, which can effectively avoid the blockage of the powder conveying riser when the coal powder enters the riser 2 from the powder bin 1. The air-powder mixer 3 is composed of a guide cylinder 12, a wind shield angle 13 and a guide plate 14. The air-powder mixer 3 has a horizontal air flow inlet and a powder inlet 15. The top of the powder inlet 15 is connected to a square rotating circular pipe 16 and a bend 17 in sequence. The bend 17 is connected to the end of the riser 2 to improve the controllability of the powder falling into the air-powder mixer 3. The guide cylinder 12 is located at the bottom of the front section of the air-powder mixer 3, the wind shield angle 13 is located below the middle section powder inlet 15, the guide plate 14 is located in the middle section of the air-powder mixer 3 and is parallel to the gas flow direction of the air flow inlet, and circular through holes are evenly distributed in a part of the guide plate 14. The front section of the air-powder mixer 3 has a reduced diameter feature, and the rear section has an expanded diameter feature. The overall structure can improve the uniformity of the pressure distribution of the air-powder mixer 3. The air supply system 4 includes an air filter 5, an air dryer 6, an air compressor 7, an air storage tank 9 and a gas delivery pipeline interconnected between these devices. A pressure regulating valve 8, a safety valve 10 and a flow meter 11 are installed on the gas pipeline.

[0027] The automatic control system is connected to the powder bin 1, the vertical pipe 2 and the air supply system 4 of the air-powder mixer 3 to achieve quantitative regulation of the inlet air flow. The automatic control system adopts a fuzzy control algorithm or a PID control algorithm to achieve optimal regulation of the powder feed.

[0028] The above-mentioned principle of optimizing the pressure distribution of the air-powder mixer in the boiler powder feeding system to improve the pressure distribution is as follows:

[0029] like Figure 2 As shown, first, the setting of the guide cylinder 12 plays the role of guiding and preliminary acceleration, allowing more gas to pass over the guide plate 14; secondly, a local nozzle structure is formed between the wind shield angle 13 and the guide plate 14, generating an accelerated airflow, thereby forming a low-pressure area behind the wind shield angle 13 to promote coal powder feeding; in addition, the optimized structure produces a larger cross-sectional velocity gradient in the area behind the wind shield angle 13, which is more conducive to coal powder dispersion. Finally, optimizing the position of the guide plate 14 can reduce structural resistance. The optimized structure produces a stable and controllable positive pressure gradient between the pressure measuring points P1 and P2, which is conducive to the stability and uniformity of material feeding.

[0030] Although the present invention has been described above with preferred embodiments, it is not intended to limit the present invention. A person skilled in the art of the present invention may make various modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the definition of the claims.

Claims

1. A boiler powder feeding system for optimizing the pressure distribution of an air-powder mixer, comprising a powder bin (1), a vertical pipe (2), an air-powder mixer (3), an air supply system (4), and an automatic control system; the powder bin (1) is connected to the air-powder mixer (3) via the vertical pipe (2), and the air supply system (4) is connected to the air-powder mixer (3); characterized in that: The air-powder mixer (3) is provided with a measuring system for real-time monitoring of the pressure and temperature of each pipeline and internal equipment of the boiler powder feeding system; the automatic control system is respectively connected to the powder bin (1), the riser (2), the air-powder mixer (3), and the gas supply system (4); the automatic control system monitors the boiler operating status in real time, and quantitatively adjusts the airflow of the powder bin (1), the riser (2), the air-powder mixer (3), and the gas supply system (4) according to the boiler operating status.

2. A boiler powder feeding system for optimizing the pressure distribution of the air-powder mixer according to claim 1, characterized in that: The air-powder mixer (3) comprises: a powder inlet (15), a flow guide cylinder (12), and a wind shield angle (13). The flow guide cylinder (12) is arranged at the bottom of the air-powder mixer (3) on the side close to the air supply system, and the wind shield angle (13) is arranged below the powder inlet (15). When the air supply system outputs airflow to the air-powder mixer (3), the direction of the airflow is changed by the flow guide cylinder (12) and the wind shield angle (13), thereby improving the uniformity of the pressure distribution of the air-powder mixer.

3. A boiler powder feeding system for optimizing the pressure distribution of the air-powder mixer according to claim 2, characterized in that: The air-powder mixer (3) further comprises a guide plate (14), which is arranged in the middle section of the air-powder mixer (3) and parallel to the gas flow direction of the air inlet, and the guide plate (14) has circular through holes evenly distributed thereon, which are used to improve the air flow velocity in the air-powder mixer (3).

4. A boiler powder feeding system for optimizing the pressure distribution of the air-powder mixer according to claim 2, characterized in that: The upper part of the powder inlet (15) of the air-powder mixer is connected to a square-to-circular pipe (16) and a curved pipe (17) in sequence, and the curved pipe (17) is connected to the end of the vertical pipe (2) to improve the controllability of the powder falling from the vertical pipe (2) into the air-powder mixer (3).

5. A boiler powder feeding system for optimizing the pressure distribution of the air-powder mixer according to claim 4, characterized in that: The measuring system comprises a sensor P1 and a sensor P2, wherein the sensor P1 is arranged in a rear area of ​​the curved pipe (17), and the sensor P2 is arranged in a rear area of ​​the windshield corner (13), and the sensor P1 and the sensor P2 are used to measure the pressure gradient of the corresponding arrangement area, so as to realize dynamic optimization and adjustment of the powder feeding.

6. A boiler powder feeding system for optimizing the pressure distribution of the air-powder mixer according to claim 1, characterized in that: The gas supply system comprises: an air filter (5), an air dryer (6), an air compressor (7), and a gas storage tank (9) which are connected in sequence through a gas pipeline; the air filter (5) serves as the input end of the gas supply system; a pressure regulating valve (8) is installed on the gas pipeline between the air compressor (7) and the inlet of the gas storage tank (9); a safety valve (10) and a flow meter (11) are installed in sequence after the outlet of the gas storage tank (9); and the output end of the flow meter serves as the output end of the gas supply system; The pressure regulating valve (8), the safety valve (10) and the flow meter (11) are respectively connected to an automatic control system, and the automatic control system realizes automatic control of the air system according to the monitoring values ​​of the regulating valve (8), the safety valve (10) and the flow meter (11).

7. A boiler powder feeding system for optimizing the pressure distribution of the air-powder mixer according to claim 1, characterized in that: The powder bin (1) is of a cone structure, and the side wall of the cone is provided with a fluidizing air inlet for realizing self-regulation of the fluidity and uniformity of the powder.

8. A boiler powder feeding system for optimizing the pressure distribution of an air-powder mixer according to claim 1, characterized in that: The riser (2) is provided with a coal extraction air system, which can avoid blockage when powder materials are transported into the riser (2).

9. A boiler powder feeding system for optimizing the pressure distribution of the air-powder mixer according to claim 1, characterized in that: The automatic control system adopts fuzzy control algorithm or PID control algorithm to achieve optimal regulation of powder feeding.

10. A boiler powder feeding system for optimizing the pressure distribution of an air-powder mixer according to claim 1, characterized in that: The powder bin (1) is provided with temperature, humidity and pressure sensors connected to an automatic control system, which are used to monitor the storage environment of the powder in real time and ensure the quality of the powder.

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