A method for controlling water addition of industrial boilers

Abstract

This invention relates to the field of industrial boiler technology, specifically to an industrial boiler water injection control method and system, comprising: responding to a liquid level warning command sent by a liquid level warning device, sending a first feeding command to a control terminal to cause the fuel storage hopper to inject additional redundant fuel into the combustion chamber; finding the corresponding first water injection rate, first water injection duration, and second water injection pressure threshold in an operating parameter lookup table based on an upward trend; continuously injecting water into the heating furnace through a water pump based on the first water injection rate and first water injection duration; during this period, monitoring the pressure value at the outlet of the heating furnace in real time through a pressure gauge; reducing the water injection rate to maintain the pressure at the outlet of the heating furnace within a preset range; and adjusting the water injection rate and duration in advance by monitoring and predicting the high-pressure steam pressure value trend in real time during water injection to ensure that the pressure value of the high-pressure steam provided by the heating furnace is always maintained within the preset threshold range, thereby improving the pressure supply stability of the industrial boiler.

Description

Technical Field

[0001] The invention relates to the technical field of industrial boilers, and in particular to an industrial boiler water adding control method. Background Art

[0002] In the process of boiling water to produce high-pressure steam, existing industrial boilers need to regularly add fresh water to the heating furnace to compensate for the loss of high-pressure steam during energy conversion. Currently, water addition compensation for industrial boilers usually uses a single signal reference source, such as a liquid level meter for detecting the water level in the heating furnace. By real-time monitoring the value of the liquid level meter, when the preset water addition level is reached, water is directly injected according to the preset water addition speed until it is filled to the normal working water level.

[0003] However, for some high-precision industrial boilers, the pressure value of the high-pressure steam they provide needs to be maintained within a preset threshold range. However, the temperature of the injected water and the water temperature in the heating furnace are quite different. During the continuous large-scale water injection process, the pressure value of the high-pressure steam may drop below the threshold range, thereby causing the output pressure value of the high-pressure steam to be unstable. Summary of the invention

[0004] The purpose of the present invention is to provide an industrial boiler water addition control method and system to improve the above-mentioned problem. However, for some high-precision industrial boilers, the pressure value of the high-pressure steam provided by them needs to be maintained within a preset threshold range at all times. However, the temperature of the injected water and the water temperature in the heating furnace are quite different. During the continuous large-scale water injection process, the pressure value of the high-pressure steam may drop below the threshold range, thereby causing the output pressure value of the high-pressure steam to be unstable.

[0005] In order to achieve the above objectives, the present application provides the following technical solutions:

[0006] On the one hand, an embodiment of the present application provides an industrial boiler water supply control method, which is applicable to an industrial boiler water supply control system, wherein the system includes a liquid level alarm device for detecting the liquid level and a pressure gauge for detecting the pressure at the pressure relief port of the heating furnace, and the method includes:

[0007] In response to the liquid level warning instruction sent by the liquid level warning device, a first fuel adding instruction is sent to the control terminal, so that the fuel storage bucket adds additional redundant fuel to the combustion chamber, thereby increasing the fire in the combustion chamber, and when the pressure value of the pressure gauge reaches the first water injection pressure threshold, the pressure value rising trend is calculated based on the pressure value fluctuation curve in the most recent first time period, and the corresponding first water injection speed, first water injection duration and second water injection pressure threshold are found in the operation parameter comparison table based on the rising trend;

[0008] When the pressure value of the pressure gauge reaches the second water injection pressure threshold, water is continuously injected into the heating furnace through the water pump based on the first water injection speed and the first water injection time. During this period, the pressure value at the outlet of the heating furnace is monitored in real time through the pressure gauge, and when the pressure value decreases at a rate greater than the first threshold, the water injection speed is reduced to maintain the pressure at the outlet of the heating furnace within a preset range;

[0009] The step of calculating the pressure value rising trend based on the pressure value fluctuation curve in the most recent first time period includes:

[0010] The pressure value fluctuation curve is sliced ​​based on the time series, thereby obtaining pressure value fluctuation line segments within multiple unit times;

[0011] Calculate the slope of each pressure value fluctuation line segment in turn, and remove the pressure value fluctuation line segments with a slope lower than a first preset slope, thereby obtaining multiple valid slopes, and calculate the average slope based on the multiple valid slopes, wherein the average slope is used to characterize the rising trend of the pressure value;

[0012] Wherein, when the pressure value decreasing rate is greater than the first threshold value, the water injection speed is reduced so that the pressure at the outlet of the heating furnace is maintained within a preset range, including:

[0013] The second pressure value fluctuation curve in the most recent second time period is intercepted in real time, and the second slope corresponding to the second pressure value fluctuation curve is calculated. When the second slope is less than the second threshold value, it indicates that the pressure value decreases too quickly. The water injection speed of the water pump is reduced based on the difference between the second slope and the second threshold value, and the water injection completion time node is corrected based on the reduced water injection speed. The second pressure value fluctuation curve before the water injection completion time node is predicted through the Kalman filter algorithm, and the current water injection speed is fine-tuned multiple times based on the second pressure value fluctuation curve.

[0014] Optionally, after fine-tuning the current water injection speed multiple times based on the second pressure value fluctuation curve, the method further includes:

[0015] When the water injection speed reaches the minimum water injection threshold after multiple fine-tunings, and the second slope is still less than the second threshold, the infrared image composite flame detector disposed in the combustion chamber detects the heat distribution diagram in the current combustion chamber;

[0016] Determine whether there is a non-combustion area in the heat distribution map based on a preset color threshold, and calculate the first area corresponding to the plurality of non-combustion areas, and send a first cleaning instruction when the first area is greater than a first cleaning area threshold, so that the operator performs a cleaning operation to remove the fuel waste residue in the combustion chamber;

[0017] If the first area is smaller than a first cleaning area threshold, the color uniformity corresponding to the heat distribution diagram is calculated, and when the color uniformity is smaller than a first uniformity threshold, a combustion chamber fan power compensation amount is calculated based on a difference between the color uniformity and the first uniformity threshold, thereby increasing the ventilation volume of the combustion chamber;

[0018] If the color uniformity is greater than the first uniformity threshold, the water injection operation is stopped and a troubleshooting request is sent to the control console so that the operator can manually troubleshoot the industrial boiler fault.

[0019] Optionally, calculating the color uniformity corresponding to the heat distribution map includes:

[0020] Construct multiple different uniformity detection area mapping frameworks based on the distribution of combustion chamber air ducts;

[0021] Overlaying the uniformity detection area mapping frame onto the heat distribution map, and intercepting the corresponding heat distribution sub-maps in multiple frames;

[0022] The heat distribution sub-graph is used to extract the color information in the heat distribution sub-graph through the HSV color model, and the number of pixels corresponding to each color level is counted, thereby obtaining the color histogram corresponding to the heat distribution sub-graph;

[0023] The color uniformity is calculated based on the color histogram using the standard deviation.

[0024] In a second aspect, this embodiment provides.

[0025] The beneficial effects of the present invention are:

[0026] The present invention provides an industrial boiler water addition control method and system, which monitors and predicts the trend of high-pressure steam pressure value in real time during water injection and adjusts the water injection speed and duration in advance, so that the pressure value of the high-pressure steam provided by the heating furnace is always maintained within a preset threshold range, thereby improving the pressure supply stability of the industrial boiler.

[0027] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a flow chart of an industrial boiler water addition control method described in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] It should be noted that similar reference numerals or letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0032] Example 1

[0033] like Figure 1 As shown, this embodiment provides an industrial boiler water supply control method, which is applicable to an industrial boiler water supply control system. The system includes a liquid level alarm arranged in a heating furnace for detecting the liquid level and a pressure gauge for detecting the pressure at a pressure relief port of the heating furnace. The method includes step S100 and step S200.

[0034] Step S100, in response to the liquid level warning instruction sent by the liquid level alarm device, a first charging instruction is sent to the control terminal, so that the fuel storage bucket adds additional redundant fuel to the combustion chamber, thereby increasing the fire in the combustion chamber, and when the pressure value of the pressure gauge reaches the first water injection pressure threshold, the pressure value rising trend is calculated based on the pressure value fluctuation curve in the most recent first time period, and the corresponding first water injection speed, first water injection duration and second water injection pressure threshold are found in the operation parameter comparison table based on the rising trend;

[0035] Step S200: When the pressure value of the pressure gauge reaches the second water injection pressure threshold, water is continuously injected into the heating furnace through the water pump based on the first water injection speed and the first water injection time, during which the pressure value at the outlet of the heating furnace is monitored in real time through the pressure gauge, and when the pressure value decreases at a rate greater than the first threshold, the water injection speed is reduced to maintain the pressure at the outlet of the heating furnace within a preset range;

[0036] The step S100 of calculating the pressure value rising trend based on the pressure value fluctuation curve in the most recent first time period includes:

[0037] Step S110, slicing the pressure value fluctuation curve based on the time series to obtain pressure value fluctuation line segments within a plurality of unit times;

[0038] Step S120, calculating the slope of each pressure value fluctuation line segment in turn, and eliminating the pressure value fluctuation line segments with a slope lower than a first preset slope, thereby obtaining a plurality of valid slopes, and calculating a mean slope based on the plurality of valid slopes, wherein the mean slope is used to characterize the rising trend of the pressure value;

[0039] Wherein, in step S200, when the pressure value decreasing rate is greater than the first threshold value, the water injection speed is reduced so that the pressure at the outlet of the heating furnace is maintained within a preset range, including:

[0040] Step S210, intercepting the second pressure value fluctuation curve in the most recent second time period in real time, and calculating the second slope corresponding to the second pressure value fluctuation curve. When the second slope is less than the second threshold value, it indicates that the pressure value decreases too quickly. Based on the difference between the second slope and the second threshold value, the water injection speed of the water pump is reduced, and the water injection completion time node is corrected based on the reduced water injection speed. The second pressure value fluctuation curve before the water injection completion time node is predicted through the Kalman filter algorithm, and the current water injection speed is fine-tuned multiple times based on the second pressure value fluctuation curve.

[0041] Secondly, after the current water injection speed is fine-tuned multiple times based on the second pressure value fluctuation curve in step S210 of this embodiment, the following steps are also included:

[0042] Step S220: when the water injection speed reaches the minimum water injection threshold after multiple fine-tunings, and the second slope is still less than the second threshold, the infrared image composite flame detector provided in the combustion chamber detects the heat distribution diagram in the current combustion chamber;

[0043] Step S230: determining whether there is a non-combustion zone in the heat distribution map based on a preset color threshold, and calculating first areas corresponding to a plurality of non-combustion zones; and sending a first cleaning instruction when the first area is greater than a first cleaning area threshold, so that an operator performs a cleaning operation to remove fuel waste residue in the combustion chamber;

[0044] Step S240: if the first area is smaller than the first cleaning area threshold, the color uniformity corresponding to the heat distribution diagram is calculated, and when the color uniformity is smaller than the first uniformity threshold, the combustion chamber fan power compensation amount is calculated based on the difference between the color uniformity and the first uniformity threshold, thereby increasing the ventilation volume of the combustion chamber;

[0045] Step S250: If the color uniformity is greater than the first uniformity threshold, the water injection operation is stopped, and a troubleshooting request is sent to the control console so that the operator can manually troubleshoot the industrial boiler fault.

[0046] The present embodiment provides an industrial boiler water addition control method, which adjusts the water injection speed and duration in advance by real-time monitoring and predicting the trend of the high-pressure steam pressure value during the water injection period, so that the pressure value of the high-pressure steam provided by the heating furnace is always maintained within a preset threshold range, thereby improving the pressure supply stability of the industrial boiler.

[0047] Secondly, in step S240, the specific implementation method of calculating the color uniformity corresponding to the heat distribution map can be:

[0048] Step S241, constructing a plurality of different uniformity detection area mapping frameworks based on the distribution of the combustion chamber air duct;

[0049] Step S242, overlaying the uniformity detection area mapping frame onto the heat distribution map, and intercepting corresponding heat distribution sub-maps in multiple frames;

[0050] Step S243, extracting color information from the heat distribution sub-graph through the HSV color model, and counting the number of pixels corresponding to each color level, thereby obtaining a color histogram corresponding to the heat distribution sub-graph;

[0051] Step S244: Calculate the corresponding color uniformity based on the color histogram through the standard deviation.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An industrial boiler water supply control method, applicable to an industrial boiler water supply control system, the system comprising a liquid level alarm device for detecting the liquid level in a heating furnace and a pressure gauge for detecting the pressure at a pressure relief port of the heating furnace, characterized in that: The method comprises: In response to the liquid level warning instruction sent by the liquid level warning device, a first fuel adding instruction is sent to the control terminal, so that the fuel storage bucket adds additional redundant fuel to the combustion chamber, thereby increasing the fire in the combustion chamber, and when the pressure value of the pressure gauge reaches the first water injection pressure threshold, the pressure value rising trend is calculated based on the pressure value fluctuation curve in the most recent first time period, and the corresponding first water injection speed, first water injection duration and second water injection pressure threshold are found in the operation parameter comparison table based on the rising trend; When the pressure value of the pressure gauge reaches the second water injection pressure threshold, water is continuously injected into the heating furnace through the water pump based on the first water injection speed and the first water injection time. During this period, the pressure value at the outlet of the heating furnace is monitored in real time through the pressure gauge, and when the pressure value decreases at a rate greater than the first threshold, the water injection speed is reduced to maintain the pressure at the outlet of the heating furnace within a preset range; The step of calculating the pressure value rising trend based on the pressure value fluctuation curve in the most recent first time period includes: The pressure value fluctuation curve is sliced ​​based on the time series, thereby obtaining pressure value fluctuation line segments within multiple unit times; Calculate the slope of each pressure value fluctuation line segment in turn, and remove the pressure value fluctuation line segments with a slope lower than a first preset slope, thereby obtaining multiple valid slopes, and calculate the average slope based on the multiple valid slopes, wherein the average slope is used to characterize the rising trend of the pressure value; Wherein, when the pressure value decreasing rate is greater than the first threshold value, the water injection speed is reduced so that the pressure at the outlet of the heating furnace is maintained within a preset range, including: The second pressure value fluctuation curve in the most recent second time period is intercepted in real time, and the second slope corresponding to the second pressure value fluctuation curve is calculated. When the second slope is less than the second threshold value, it indicates that the pressure value decreases too quickly. The water injection speed of the water pump is reduced based on the difference between the second slope and the second threshold value, and the water injection completion time node is corrected based on the reduced water injection speed. The second pressure value fluctuation curve before the water injection completion time node is predicted through the Kalman filter algorithm, and the current water injection speed is fine-tuned multiple times based on the second pressure value fluctuation curve.

2. The industrial boiler water supply control method according to claim 1, characterized in that: After the current water injection speed is fine-tuned multiple times based on the second pressure value fluctuation curve, the method further includes: When the water injection speed reaches the minimum water injection threshold after multiple fine-tunings, and the second slope is still less than the second threshold, the infrared image composite flame detector disposed in the combustion chamber detects the heat distribution diagram in the current combustion chamber; Determine whether there is a non-combustion area in the heat distribution map based on a preset color threshold, and calculate the first area corresponding to the plurality of non-combustion areas, and send a first cleaning instruction when the first area is greater than a first cleaning area threshold, so that the operator performs a cleaning operation to remove the fuel waste residue in the combustion chamber; If the first area is smaller than a first cleaning area threshold, the color uniformity corresponding to the heat distribution diagram is calculated, and when the color uniformity is smaller than a first uniformity threshold, a combustion chamber fan power compensation amount is calculated based on a difference between the color uniformity and the first uniformity threshold, thereby increasing the ventilation volume of the combustion chamber; If the color uniformity is greater than the first uniformity threshold, the water injection operation is stopped and a troubleshooting request is sent to the control console so that the operator can manually troubleshoot the industrial boiler fault.

3. The industrial boiler water supply control method according to claim 2, characterized in that: The calculating the color uniformity corresponding to the heat distribution map includes: Construct multiple different uniformity detection area mapping frameworks based on the distribution of combustion chamber air ducts; Overlaying the uniformity detection area mapping frame onto the heat distribution map, and intercepting the corresponding heat distribution sub-maps in multiple frames; The heat distribution sub-graph is used to extract the color information in the heat distribution sub-graph through the HSV color model, and the number of pixels corresponding to each color level is counted, thereby obtaining the color histogram corresponding to the heat distribution sub-graph; The color uniformity is calculated based on the color histogram using the standard deviation.

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