A method for automatically controlling the fire failure of the burnout chamber of a boiler

Abstract

The present invention discloses a method for automatically controlling a boiler burnout chamber fire, comprising the steps of: S1, obtaining a flame image of the boiler burnout chamber and transmitting it to a computer; S2, the computer analyzing and edge processing the obtained flame image; S3, calculating the ratio of flame pixels in the burnout chamber image to the total pixels in the image; and S4, transmitting a pixel digital quantity signal to a PLC controller, comparing the percentage of flame pixels to image pixels with a fire setting value of a host computer, and determining whether the burnout chamber has fire or not. The method of the present invention does not require manual operation, is simple and convenient to use, has high practical value, avoids coal waste, saves coal, and transmits the image to the computer for easy observation by the boiler operator, reducing the boiler operator's back-and-forth work and improving work efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler control methods, and in particular to a method for automatically controlling the fire failure of a burnout chamber of a boiler. Background Art

[0002] Domestic chain and reciprocating boiler controls are divided into manual control mode and automatic control mode. Manual control mode is to manually set the boiler motor frequency, and automatic mode is to automatically set the boiler motor frequency. At the same time, the air-coal ratio can be automatically controlled (also called self-optimization mode).

[0003] Combustion in both manual and automatic control modes can be affected by the type and quality of the coal, or by insufficient blast airflow. This can lead to incomplete combustion in the burnout chamber, causing the coal to fall into the slag discharger, resulting in coal waste. Typically, boiler operators manually adjust the boiler motor frequency based on field experience, as this cannot be automated.

[0004] During the combustion process, if the boiler operator discovers a misfire while inspecting the burnout chamber, he or she will manually adjust the boiler motor frequency (increasing the blast frequency, increasing the induced draft frequency, decreasing the grate frequency, and decreasing the coal layer frequency). If the boiler operator fails to detect this in time, a large amount of unburned coal will fall into the slag remover, wasting energy and causing unnecessary waste. Currently, chain and reciprocating boilers use this manual control mode, which is inefficient and lacks detection or automated processing capabilities. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a method for automatically controlling the fire failure of a burnout chamber of a boiler.

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0007] The present invention provides a method for automatically controlling the fire failure of a burnout chamber of a boiler, comprising the following steps:

[0008] S1. Obtain the flame image of the boiler burnout chamber and transmit it to the computer;

[0009] S2, the computer analyzes and processes the flame image;

[0010] S3, calculating the ratio of flame pixels in the burnout chamber image to the total pixels in the image;

[0011] S4, the pixel digital signal is transmitted to the PLC controller, and the percentage of flame pixels to image pixels is compared with the fire-off setting value of the host computer to determine whether the burnout chamber has fire or not;

[0012] S5. When the percentage of flame pixels in the image pixels is greater than or equal to the fire-off setting value of the host computer, it is determined that the burnout chamber has a fire; when the percentage of flame pixels in the image pixels is less than the fire-off setting value of the host computer, it is determined that the burnout chamber has not a fire;

[0013] S6. If it is determined that the burnout chamber has lost fire, the fire-loss program is executed: the AO analog module of the PLC controller is driven to control the frequency converter through the 4-20ma analog signal instruction, thereby increasing the blast frequency, increasing the induced draft frequency, decreasing the grate frequency, and decreasing the coal layer frequency. At the same time, the acquisition of the boiler burnout chamber flame image is stopped; if it is determined that the burnout chamber has not lost fire, the last boiler blast frequency, induced draft frequency, coal layer frequency, and grate frequency are automatically restored;

[0014] S7. Loop back to step S1.

[0015] Furthermore, in step S1, an industrial CCD camera is used to obtain a flame image of the boiler burnout chamber.

[0016] Furthermore, the industrial CCD cameras are installed on both sides of the boiler burnout chamber, and use a self-optimization mode to photograph the flame of the boiler burnout chamber every 1-5 minutes.

[0017] Furthermore, step S2 analyzes and processes the edge of the flame image RGB using hancon software or VB2010 software.

[0018] Furthermore, in step S4, the upper computer misfire setting value range is 80-100%.

[0019] Furthermore, the pixel digital signal of step S4 is transmitted to the PLC controller via standard MODBUS-RTU protocol communication.

[0020] Furthermore, the PLC controller in step S4 is a Siemens S7-300 PLC controller.

[0021] Furthermore, in step S6, the blast frequency is increased in the range of 1.0 Hz to 2.0 Hz, the coal seam frequency is decreased in the range of 0.5 Hz to 2.0 Hz, and the grate frequency is decreased in the range of 0.5 Hz to 3.0 Hz.

[0022] Furthermore, in step S6, the induced draft frequency is automatically controlled by setting a parameter range of -10 to -25 according to the computer pressure difference.

[0023] Compared with the existing technology, the beneficial effects of the present invention are:

[0024] The present invention automatically analyzes and processes the flame pixels of the burnout chamber. When the burnout chamber fails due to insufficient boiler medium, coal type and blast air volume, the system automatically reduces the speed of the grate, reduces the speed of the coal seam, and increases the blast frequency. No manual operation is required, so the system is simple and convenient to use and has high practical value. It avoids coal waste and saves coal. The pictures are transmitted to the computer for easy observation by the boiler operator, reducing the boiler operator's back and forth work and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural block diagram of the automatic control principle provided by an embodiment of the present invention.

[0026] Figure 2 This is a picture taken by a CCD camera in Example 1 of the present invention.

[0027] Figure 3 This is a picture processed with colors and edges according to Example 1 of the present invention.

[0028] Figure 4 This is a picture taken by a CCD camera in Example 2 of the present invention.

[0029] Figure 5 This is a picture of color and edge processing according to Example 2 of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0031] Example 1 Burnout Chamber Fire Procedure

[0032] like Figure 1 The method for automatically controlling the flame failure of the boiler burnout chamber shown in the figure uses two industrial CCD cameras installed on both sides of the boiler burnout chamber. The flame of the boiler burnout chamber is photographed every 3 minutes. After the photographed pictures are transmitted to the computer, the computer obtains the flame pictures, such as Figure 2 shown.

[0033] Use Hancon software or VB2010 software to analyze and process the flame image RGB. Automatically calculate the flame pixels and total pixels of the burnout chamber image, such as Figure 3 The pixel digital signal is sent to the Siemens S7-300 PLC controller via the standard MODBUS-RTU protocol. The S7-300 PLC controller receives the flame pixels and total pixels of the image, compares the percentage of flame pixels in the image with the flame failure setting value of the host computer, and determines whether the burnout chamber has failed or not failed.

[0034] Taking pictures of the burnout chamber and extracting pixels are divided into two parts. One part is that the total number of pixels in the picture is A, which is 200,000, and the other part is that the number of pixels of the flame in the picture is B, which is 182,300. Calculate the percentage (%) C of the number of flame pixels in the total number of pixels in the picture:

[0035] C = B / A×100

[0036] C = 182300 / 200000*100 = 91.15

[0037] The number of flame pixels accounts for 91.15% of the total number of pixels in the picture

[0038] Set the range of the percentage (%) D of the fire-off coefficient set by the host computer to 80 - 100%.

[0039] Compare C and D. When C >= D, the burnout chamber has a fire-off; when C < D, the burnout chamber does not have a fire-off.

[0040] In this embodiment, to judge the fire-off of the burnout chamber, drive the AO analog module outside the PLC controller, and through the 4 - 20ma analog signal instruction, control the frequency converter to control the increase of the air supply frequency, the decrease of the grate frequency, and the decrease of the coal layer frequency. <s

[0041] The boiler operation of the present invention adopts a self-optimizing mode control, optimizing the boiler once every 3 minutes. The optimization result controls the air supply frequency Hz of the boiler. Each time of optimization controls the increase or decrease of the air supply frequency of the boiler by (0.02 - 0.075) Hz, effectively controlling the air-to-coal ratio of the boiler. The induced draft frequency is set according to the computer differential pressure parameter (range: -10 ~ -25), and the induced draft frequency Hz is automatically controlled by PID regulation, and the boiler is in a slightly negative pressure state. Ensure the safety of the boiler.

[0042] When the burnout chamber of the boiler has a fire-off, execute the fire-off procedure once:

[0043] GF’ = GF + 1.5Hz = 25HZ + 1.5HZ = 26.5Hz;

[0044] MC’ = MC - 1.0Hz = 12HZ - 1.0HZ = 11Hz;

[0045] LP’ = LP - 2.0Hz = 24HZ - 2.0HZ = 22Hz;

[0046] GF: The current operating frequency of the boiler air supply is 25Hz;

[0047] MC: The current operating frequency of the boiler coal layer is 12Hz;

[0048] LP: The current operating frequency of the boiler grate is 24Hz;

[0049] When the boiler executes the flameout program, the boiler self-optimization stops running, and the boiler blast frequency HZ maintains the self-optimization frequency HZ.

[0050] Example 2 Combustion Chamber Non-Flameout Program

[0051] Such as Figure 1 shown, a method for automatically controlling the flameout of the boiler combustion chamber, using two industrial CCD cameras installed on both sides of the boiler combustion chamber. The flame of the boiler combustion chamber is photographed every 3 minutes, and the taken picture is transmitted to the computer. The computer obtains the flame picture, as Figure 4 shown.

[0052] Through Hancon software or VB2010 software, the flame picture R.G.B (primary colors of light) is analyzed and edge processed. Automatically calculate the flame pixels and the total pixels of the combustion chamber picture, as Figure 5 shown. This pixel digital signal is communicated through the standard MODBUS-RTU protocol and sent to the Siemens S7-300 PLC controller. The S7-300 PLC controller receives the flame pixels and the total pixels of the picture, and compares according to the percentage of the flame pixels in the picture pixels and the set value of the flameout of the upper computer to judge whether the combustion chamber has a flameout or not.

[0053] Extracting the pixels of the picture of the combustion chamber is divided into two parts. One part is that the total pixels of the picture is A, and the total pixels is 200,000. The other part is that the flame pixels of the picture is B, and the pixels is 112,300. Calculate the percentage (%) C of the flame pixels in the total pixels of the picture:

[0054] C = B / A × 100

[0055] C = 112300 / 200000 * 100 = 56.15

[0056] The flame pixels account for 56.15% of the total pixels of the picture.

[0057] Set the range of the set flameout coefficient percentage (%) D of the upper computer to 80 - 100%.

[0058] Compare C and D. When C < D, it is detected that there is no flameout of the flame pixels, and the system will automatically restore the previous boiler blast frequency, coal bed frequency, and grate frequency.

[0059] For example: In this embodiment, the previous self-optimization running frequency of the blast is 25HZ, the grate frequency is 24HZ, and the coal bed frequency is 12HZ. Then the blast is restored to 25Hz. The grate is restored to 24HZ, and the coal bed is restored to 12HZ. The system automatically restores the self-optimization mode control, and the self-optimization automatically controls the blast to perform automatic control of the air-coal ratio. The induced draft frequency is automatically controlled according to the computer differential pressure setting parameter (range -10 ~ -25), and the induced draft frequency HZ is controlled.

[0060] This cycle repeats itself, and when the flame pixel is detected to be off for the second time, the system will automatically continue to execute the off-fire procedure as in Example 1.

[0061] The present invention automatically analyzes and processes burnout chamber flame pixels. When the burnout chamber flames occur due to insufficient boiler medium, coal type, and blast air volume, the system automatically reduces the speed of the grate and coal layer, and increases the blast frequency. Manual operation is unnecessary, making the system simple and convenient to use, highly practical, and avoiding coal waste. Images are transmitted to a computer for easy observation by the stoker, reducing their back-and-forth work and improving work efficiency. The method of the present invention has been proven effective over a heating period, demonstrating promising promotional and energy-saving benefits.

[0062] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims

1. A method for automatically controlling the fire failure of a boiler burnout chamber, characterized in that: The following steps are involved: S1. Obtain the flame image of the boiler burnout chamber and transmit it to the computer; S2. The computer analyzes and processes the flame image; S3, calculating the ratio of flame pixels in the burnout chamber image to the total pixels in the image; S4. The pixel digital signal is transmitted to the PLC controller, and the percentage of flame pixels in the image pixels is compared with the upper computer's fire failure setting value to determine whether the burnout chamber has fire or not; the upper computer's fire failure setting value range is 80-100%; S5. When the percentage of flame pixels in the image pixels is greater than or equal to the fire-off setting value of the host computer, it is determined that the burnout chamber has a fire; when the percentage of flame pixels in the image pixels is less than the fire-off setting value of the host computer, it is determined that the burnout chamber has not a fire; S6. If it is determined that the burnout chamber has lost fire, the fire-loss program is executed: the PLC controller peripheral AO analog module is driven to control the frequency converter through a 4-20ma analog signal instruction, thereby increasing the blast frequency, increasing the induced draft frequency, decreasing the grate frequency, and decreasing the coal layer frequency. At the same time, the acquisition of the boiler burnout chamber flame image is stopped; the blast frequency increase range is 1.0Hz-2.0Hz, the coal layer frequency reduction range is 0.5Hz-2.0Hz, and the grate frequency reduction range is 0.5Hz-3.0Hz. The induced draft frequency is automatically controlled according to the computer pressure difference setting parameter range of -10Hz to -25Hz; if it is determined that the burnout chamber has not lost fire, the last boiler blast frequency, induced draft frequency, coal layer frequency, and grate frequency are automatically restored; S7. Loop back to step S1.

2. The method for automatically controlling the fire failure of the burnout chamber of a boiler according to claim 1, characterized in that: In step S1, an industrial CCD camera is used to obtain a flame image of the boiler burnout chamber.

3. The method for automatically controlling the fire failure of the burnout chamber of a boiler according to claim 2, characterized in that: The industrial CCD cameras are installed on both sides of the boiler burnout chamber and use a self-optimization mode to shoot the flame of the boiler burnout chamber every 1-5 minutes.

4. The method for automatically controlling the fire failure of the burnout chamber of a boiler according to claim 1, characterized in that: Step S2: Analyze and process the RGB of the flame image using Hancon software or VB2010 software.

5. The method for automatically controlling the fire failure of the burnout chamber of a boiler according to claim 1, characterized in that: The pixel digital signal in step S4 is transmitted to the PLC controller via the standard MODBUS-RTU protocol communication.

6. The method for automatically controlling the fire failure of the burnout chamber of a boiler according to claim 1, characterized in that: The PLC controller in step S4 is a Siemens S7-300 PLC controller.

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