An intelligent combustion control method for coal-fired boilers based on deep peak regulation

Abstract

The present invention belongs to the field of coal-fired boiler combustion, and specifically relates to an intelligent combustion control method for a coal-fired boiler based on deep peak regulation. The method divides a day into electricity consumption periods, and constructs an electricity consumption change curve, a combustion consumption change curve, and a combustion efficiency change curve based on the electricity consumption log of the power system and the combustion record of the coal-fired boiler. The comparison results of the three curves are then used to identify the electricity consumption period that requires combustion control, thereby achieving accurate capture of the combustion control period based on historical data, so that the peak electricity consumption period is no longer limited to a fixed period, which is more in line with actual control needs. At the same time, after identifying the electricity consumption period that requires combustion control, the feasibility of combustion temperature control is analyzed by combining the normal operating temperature range of the coal-fired boiler equipment and the ideal combustion temperature of the fuel, thereby achieving reasonable control of the combustion temperature, which is beneficial to maintaining power generation stability on the basis of ensuring normal operation of the equipment.

Description

Technical Field

[0001] The present invention belongs to the field of coal-fired boiler combustion, and in particular relates to an intelligent combustion control method for a coal-fired boiler based on deep peak regulation. Background Art

[0002] Coal-fired boiler power generation with coal as the main fuel has relatively low cost and can provide stable load power. Compared with renewable energy such as wind and solar energy, coal-fired power generation is not restricted by weather conditions and can provide electricity stably, ensuring the stability and reliability of the power grid, which makes it competitive in the power market in the long term.

[0003] Since coal-fired boilers release a large amount of pollutants when burning coal, especially when it is not completely burned, these pollutants have a negative impact on air quality. With the continuous growth of demand for electricity in modern society, fuel consumption has also increased. The resulting environmental problems cannot be underestimated. Therefore, when using coal-fired boilers for power generation, precise combustion control is required to ensure complete combustion of the fuel, improve combustion efficiency, and thus minimize energy consumption.

[0004] As we all know, low fuel efficiency usually occurs during peak electricity consumption. This is because the electricity load increases during peak electricity consumption, and more fuel is needed. At this time, if the combustion temperature and combustion time are not adjusted accordingly, it will affect the complete combustion of the fuel, thereby producing more carbon monoxide and unburned carbon, and reducing the combustion efficiency. In this case, the combustion control of coal-fired boilers is usually concentrated on the peak electricity consumption. On this basis, the combustion control of the existing technology generally selects fixed peak time periods for combustion control in order to improve the control efficiency. It does not take into account that the peak electricity consumption periods in different regions are different, and the peak electricity consumption periods in the same region have dynamic fluctuations. On the one hand, this fixed-time combustion control is difficult to capture the time periods when there is a real control demand, resulting in the inability to meet the control demand. On the other hand, it is easy to spend a lot of time and resources in the time periods when the control demand is not high, resulting in wasting resources while failing to improve the control effect.

[0005] In addition, the commonly used method to improve combustion efficiency is to increase the combustion temperature. However, the existing technology ignores the normal operating temperature of coal-fired boiler equipment when controlling the combustion temperature. Simply increasing the combustion temperature may exceed the normal operating temperature of the coal-fired boiler equipment, which will invisibly accelerate the wear and aging of the equipment, thereby significantly reducing the service life of the equipment and increasing maintenance costs and downtime. Summary of the invention

[0006] To this end, one purpose of an embodiment of the present application is to provide an intelligent combustion control method for a coal-fired boiler based on deep peak regulation, which effectively solves the problems mentioned in the background technology.

[0007] The purpose of the present invention can be achieved through the following technical solutions: A method for intelligent combustion control of coal-fired boilers based on deep peak regulation, comprising the following steps: selecting a historical monitoring period, and dividing the duration of each monitoring day in the historical monitoring period according to a set time interval to obtain a number of electricity consumption periods corresponding to each monitoring day.

[0008] The power consumption of each power consumption period on each monitoring day is extracted from the power consumption log of the power system, and the fuel consumption and combustion efficiency of each power consumption period on each monitoring day are extracted from the combustion records of the coal-fired boiler.

[0009] The distribution difference of electricity consumption in the same electricity consumption period on each monitoring day is analyzed to determine the effective electricity consumption in each electricity consumption period. Similarly, the distribution difference analysis of fuel consumption and combustion efficiency is performed to obtain the effective fuel consumption and effective combustion efficiency in each electricity consumption period.

[0010] A two-dimensional coordinate system is constructed with the electricity consumption period as the horizontal axis and the electricity consumption as the vertical axis. Several points are marked in the constructed two-dimensional coordinate system for the effective electricity consumption in each electricity consumption period to form an electricity consumption change curve. Similarly, a two-dimensional coordinate system is constructed with the electricity consumption period as the horizontal axis and the fuel consumption and combustion efficiency as the vertical axis to form a fuel consumption change curve and a combustion efficiency change curve for the effective fuel consumption and effective combustion efficiency in each electricity consumption period.

[0011] The power consumption change curve, the fuel consumption change curve, and the combustion efficiency change curve are identified for abnormalities, and the power consumption period that requires combustion control is identified and recorded as the target period.

[0012] The combustion temperature of each monitoring day during the target period is extracted from the combustion record of the coal-fired boiler, and the normal operating temperature range of the coal-fired boiler equipment is obtained, thereby determining the demand combustion control method of the coal-fired boiler during the target period.

[0013] When the adaptive combustion control mode of the coal-fired boiler in the target period is to increase the combustion temperature, the air-fuel ratio of each monitoring day in the target period is extracted from the combustion record of the coal-fired boiler, thereby determining the adaptive execution mode of increasing the combustion temperature.

[0014] In combination with all the above-mentioned technical solutions, the positive effects of the present invention are as follows: 1. The present invention divides the length of a day into electricity consumption periods, and constructs electricity consumption change curves, fuel consumption change curves, and combustion efficiency change curves based on the electricity consumption logs of the power system and the combustion records of coal-fired boilers, and then uses the comparison results of the three curves to identify the electricity consumption periods that require combustion control, thereby achieving accurate capture of combustion control periods based on historical data, so that peak electricity consumption periods are no longer limited to fixed periods, which is more in line with actual control needs. At the same time, by concentrating resources and time to perform combustion control in periods where there is a real need for control, resource waste is avoided to the greatest extent possible.

[0015] 2. After identifying the power consumption period that requires combustion control, the present invention analyzes the feasibility of combustion temperature control by combining the normal operating temperature range of the coal-fired boiler equipment and the ideal combustion temperature of the fuel, thereby achieving reasonable control of the combustion temperature. It can avoid, to a certain extent, the combustion exceeding the normal operating temperature of the coal-fired boiler equipment, which is beneficial to maintaining power generation stability on the basis of ensuring the normal operation of the equipment and prolonging the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0017] Figure 1 The present invention is a flowchart of the steps for implementing the method. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1 As shown, the present invention proposes an intelligent combustion control method for a coal-fired boiler based on deep peak regulation, comprising the following steps: selecting a historical monitoring period, and dividing the duration of each monitoring day in the historical monitoring period according to a set time interval to obtain a number of electricity consumption periods corresponding to each monitoring day.

[0020] Applied to the above embodiment, the historical monitoring period can be 6 months or one year to avoid the situation where the electricity consumption logs and combustion records extracted are too small and unrepresentative, making it difficult to establish accurate electricity consumption change curves and fuel consumption and efficiency change curves. At the same time, the historical monitoring period must be limited to the current time to avoid the situation where the electricity consumption logs and combustion records extracted are too old and cannot reflect the current control needs.

[0021] In the preferred implementation of the above scheme, the duration of a single monitoring day is 24 hours. A moment can be selected as the starting moment of the time interval, and the moment 24 hours after the starting moment is used as the ending moment. The starting moment and the ending moment constitute the time interval. For example, the starting moment is 6:00, and the set time interval is 1 hour. The divided electricity consumption time periods can be 6:00-7:00, 7:00-8:00, 8:00-9:00, 9:00-10:00, 10:00-11:00, etc.

[0022] It should be understood that the shorter the time interval is set, the more detailed the division of electricity consumption periods is, which can provide precise identification for subsequent identification of electricity consumption periods that require combustion control, which is conducive to ensuring identification accuracy.

[0023] The power consumption of each power consumption period on each monitoring day is extracted from the power consumption log of the power system, and the fuel consumption and combustion efficiency of each power consumption period on each monitoring day are extracted from the combustion records of the coal-fired boiler.

[0024] It is important to know that the power consumption log of a power system is usually a form of record that records and tracks various important parameters in the power system, among which the most important parameter is the power consumption.

[0025] Once again, it is important to know that the combustion record of a coal-fired boiler is a log that records the key parameters and operating conditions of the coal-fired boiler during its combustion process. For example, the combustion record records fuel consumption, type of fuel used, combustion time, combustion temperature, air-fuel ratio, combustion efficiency, etc., where combustion efficiency refers to the proportion of fuel converted into usable heat energy during the combustion process, and is usually evaluated by measuring the main emission gases (such as CO, CO2, NOx, etc.) through flue gas analysis instruments.

[0026] The distribution difference of electricity consumption in the same electricity consumption period on each monitoring day is analyzed to determine the effective electricity consumption in each electricity consumption period. Similarly, the distribution difference analysis of fuel consumption and combustion efficiency is performed to obtain the effective fuel consumption and effective combustion efficiency in each electricity consumption period.

[0027] As a preferred implementation of the above scheme, the distribution difference analysis of the electricity consumption in the same electricity consumption period on each monitoring day is carried out as shown in the following process: the electricity consumption in the same electricity consumption period on each monitoring day is compared, and the highest and lowest electricity consumption are selected.

[0028] The power consumption of the same power consumption period on each monitoring day is averaged to obtain the average power consumption of each power consumption period.

[0029] The maximum power consumption in each power consumption period is subtracted from the average power consumption to obtain the maximum-average power consumption difference, and the average power consumption is subtracted from the minimum power consumption to obtain the minimum-average power consumption difference.

[0030] The difference between the highest and average electricity consumption in each electricity consumption period is subtracted from the difference between the lowest and average electricity consumption, and the absolute value of the difference result is divided by the sum of the highest and lowest electricity consumption to obtain the difference in electricity consumption distribution in each electricity consumption period. When the difference between the maximum value and the average value is larger than the difference between the minimum value and the average value, it usually reflects the non-concentration of data distribution or the large degree of dispersion of distribution.

[0031] Further preferably, the effective power consumption of each power consumption period is determined as follows: the power consumption distribution difference of each power consumption period is compared with the set allowable difference. Exemplarily, the allowable difference is 0.3, where the allowable difference is initially set. The setting purpose is to assist in the selection of effective power consumption, effective fuel consumption, and effective combustion efficiency. If the power consumption distribution difference of a certain power consumption period is greater than the allowable difference, then the median power consumption of this power consumption period in each monitoring day is taken as the effective power consumption of this power consumption period; otherwise, the average power consumption of this power consumption period is taken as the effective power consumption of this power consumption period.

[0032] The present invention analyzes the distribution differences of electricity consumption in the same electricity consumption period on each monitoring day based on the existence of extreme values ​​and abnormal values, which makes the electricity consumption distribution in the same electricity consumption period on each monitoring day not present an ideal concentrated distribution. In this case, directly using the mean to represent the effective electricity consumption will have applicability limitations and will not be representative in reality.

[0033] A two-dimensional coordinate system is constructed with the electricity consumption period as the horizontal axis and the electricity consumption as the vertical axis. Several points are marked in the constructed two-dimensional coordinate system for the effective electricity consumption in each electricity consumption period to form an electricity consumption change curve. Similarly, a two-dimensional coordinate system is constructed with the electricity consumption period as the horizontal axis and the fuel consumption and combustion efficiency as the vertical axis to form a fuel consumption change curve and a combustion efficiency change curve for the effective fuel consumption and effective combustion efficiency in each electricity consumption period.

[0034] The power consumption change curve, the fuel consumption change curve, and the combustion efficiency change curve are identified for abnormalities, and the power consumption period that requires combustion control is identified and recorded as the target period.

[0035] In an optional manner, the abnormal identification of the power consumption change curve, the fuel consumption change curve, and the combustion efficiency change curve is implemented as follows: the points in the power consumption change curve and the fuel consumption change curve are mapped to obtain point groups corresponding to each power consumption period.

[0036] It should be noted that since the electricity consumption change curve and the fuel consumption change curve are constructed based on the same coordinate horizontal axis, the points on the above curves have consistent horizontal coordinates, so the points on the electricity consumption change curve and the fuel consumption change curve can be mapped through the horizontal coordinates.

[0037] The slope sign of each electricity consumption period at the midpoint of the electricity consumption change curve is compared with the slope sign of the midpoint of the fuel consumption change curve, and the electricity consumption period corresponding to the point where the slope sign is positive is selected as the same increase period.

[0038] It should be explained that since combustion control usually needs to be implemented during peak electricity consumption, and peak electricity consumption occurs during the stage of increasing electricity consumption, selecting the same increase period can narrow the time period range for identifying the electricity consumption period that needs combustion control, which is more focused and conducive to improving identification efficiency.

[0039] Compare the slope of the midpoint of the electricity consumption change curve during the same increase period with the slope of the midpoint of the fuel consumption change curve, and calculate the growth rate difference corresponding to each period of same increase. The specific calculation formula is λ=|k q -k c |, where k q , k c They respectively represent the slope of the midpoint of the electricity consumption change curve and the slope of the midpoint of the fuel consumption change curve during the same increase period.

[0040] It should be understood that as electricity consumption increases, fuel consumption will inevitably increase. Under normal circumstances, the increase in electricity consumption and the increase in fuel consumption tend to increase in proportion, that is, the difference in growth rate tends to 0. However, when the equipment load does not match (for example, under low load conditions, the equipment may find it difficult to maintain efficient combustion, resulting in an increase in fuel consumption per unit of electricity or heat), the combustion efficiency is too low, etc., the fuel consumption based on the proportional increase will be difficult to meet the increase in electricity consumption. At this time, additional fuel will be required to meet the increase in electricity consumption, and excessive fuel consumption will occur. This excessive fuel consumption is particularly evident when electricity consumption is close to a peak. Specifically, when electricity consumption remains unchanged or grows slowly, the growth rate difference can still maintain a value close to 0. When electricity consumption continues to grow until it reaches its peak, the maintained growth rate difference begins to be broken.

[0041] The growth amplitude difference corresponding to each same-increase period is compared with the normal growth amplitude difference, and the same-increase period with a larger growth amplitude difference than the normal growth amplitude difference is extracted as the asynchronous period.

[0042] It should be added that the normal growth amplitude difference mentioned above is the growth amplitude difference that can be maintained normally in the electricity consumption change curve and the fuel consumption change curve. Specifically, the growth amplitude difference corresponding to the same growth period when the growth amplitude is smaller can be used for regular analysis, and the regular growth amplitude difference can be extracted as the normal growth amplitude difference.

[0043] Extract the slope of the asynchronous period from the combustion efficiency change curve and identify the model The recognition result of whether the asynchronous period is abnormal is obtained. In the model, R=1 indicates that there is an abnormality, and R=0 indicates that there is no abnormality. η It represents the slope of the asynchronous period in the combustion efficiency change curve, k0 represents the set zero slope, ∧, ∨, They represent AND, OR, and NOT respectively. For example, k0=0.4.

[0044] In a further optional manner, identifying the power usage period that requires combustion control specifically includes: selecting an asynchronous period with abnormalities from the identification results of whether the asynchronous period is abnormal as the power usage period that requires combustion control.

[0045] From the above identification model, it can be seen that when the slope of the point where the asynchronous period is located is less than 0 or the slope is close to 0, it indicates that the combustion efficiency decreases or remains the same when the electricity consumption increases. This reflects to a certain extent that the combustion efficiency has not kept pace with the increase in electricity consumption, resulting in excessive fuel consumption.

[0046] It is important to understand that as electricity consumption increases, the system requires more energy to meet the electricity demand. If the combustion efficiency is low, the same amount of fuel may not provide enough heat or power, resulting in insufficient energy supply and system stability issues. Therefore, when electricity consumption increases, it is necessary to ensure that the combustion efficiency keeps pace, so as to ensure that more energy is provided with less fuel consumption.

[0047] What needs to be further understood is that since the combustion efficiency does not grow infinitely, the combustion efficiency has an upper limit. When judging whether the combustion efficiency keeps pace based on the flat slope of the point in the asynchronous period in the combustion efficiency change curve, it is necessary to consider whether the combustion efficiency has reached its upper limit. When the combustion efficiency reaches the upper limit, the slope cannot be kept flat to judge that the combustion efficiency has not kept pace. In general, the upper limit combustion efficiency of the fuel can usually be found in the technical manual of the boiler equipment or the relevant equipment specification documents.

[0048] The present invention compares the electricity consumption change curve with the fuel consumption change curve to identify the time period with excessive increase in fuel consumption, and finds the combustion efficiency of the corresponding time period from the combustion efficiency change curve to analyze whether it is reduced or flat. This analysis method takes into account that the reasons causing excessive fuel consumption are not only caused by combustion efficiency, but also by other reasons. By further analyzing the combustion efficiency in the period of excessive increase in fuel consumption, excessive fuel consumption due to other reasons can be eliminated, thereby ensuring that subsequent combustion control is based on combustion control under combustion efficiency.

[0049] The combustion temperature of each monitoring day during the target period is extracted from the combustion record of the coal-fired boiler, and the normal operating temperature range of the coal-fired boiler equipment is obtained, thereby determining the required combustion control method of the coal-fired boiler during the target period, which is specifically determined as follows: the type of fuel used in the coal-fired boiler is extracted from the combustion record, and the combustion temperature of the fuel in a fully burned state is obtained as the ideal combustion temperature.

[0050] It should be pointed out that the analysis of the ideal combustion temperature in the present invention is based on the premise that the fuel type used in the combustion record is the same fuel.

[0051] The ideal combustion temperature that needs to be supplemented is usually a fixed value for different fuels under complete combustion conditions. For most common fuels, their ideal combustion temperatures are known constants that can be found in references, data provided by fuel suppliers, or combustion engineering manuals. For example, the ideal combustion temperature of coal is approximately 1300°C.

[0052] The upper limit operating temperature is extracted from the normal operating temperature range of the coal-fired boiler equipment, wherein the normal operating temperature range of the coal-fired boiler equipment can be obtained from the operating instructions based on the model specifications of the coal-fired boiler equipment, and then the ideal combustion temperature is compared with the upper limit operating temperature, and the required combustion temperature is selected therefrom. Specifically, the ideal combustion temperature is compared with the upper limit operating temperature. If the ideal combustion temperature is higher than the upper limit operating temperature, the upper limit operating temperature is used as the required combustion temperature, otherwise the ideal combustion temperature is used as the required combustion temperature.

[0053] The combustion temperature of the coal-fired boiler during the target period of each monitoring day is compared with the required combustion temperature, and the expression Calculate the combustion temperature control margin of coal-fired boilers during the target period Where T i It represents the combustion temperature of the coal-fired boiler in the target period of the i-th monitoring day, i represents the monitoring day number, i=1,2,......,n, n represents the number of monitoring days in the historical monitoring period, T0 represents the required combustion temperature, e represents a natural constant, wherein the lower the combustion temperature is than the required combustion temperature, the greater the redundancy of the combustion temperature control is, and the more the combustion efficiency can be improved by increasing the combustion temperature.

[0054] The combustion temperature control margin of the coal-fired boiler in the target time period is compared with the set effective control margin. For example, the effective control margin is 0.8. If the combustion temperature control margin of the coal-fired boiler in a certain target time period is greater than the effective control margin, then the required combustion control method of the coal-fired boiler in the target time period is to increase the combustion temperature. Otherwise, it indicates that the combustion temperature is close to the required combustion temperature. At this time, it is difficult to meet the demand by increasing the combustion temperature to improve the combustion efficiency. Then the required combustion control method of the coal-fired boiler in the target time period is to extend the combustion time. This allows the fuel to burn for a longer time, which helps to improve the degree of complete combustion of the fuel, which can reduce the generation of incomplete combustion products, thereby improving combustion efficiency.

[0055] When the adaptive combustion control method of the coal-fired boiler in the target period is to increase the combustion temperature, the air-fuel ratio of each monitoring day in the target period is extracted from the combustion record of the coal-fired boiler, thereby determining the adaptive execution method for increasing the combustion temperature, which is as follows: the ideal air-fuel ratio is obtained based on the type of fuel used in the coal-fired boiler.

[0056] It is important to know that the air-fuel ratio refers to the mass or volume ratio of air and fuel during the combustion process. It is used to describe the ratio of oxygen and fuel in the fuel-air mixture. The ideal air-fuel ratio of the fuel depends on the chemical properties of the fuel and usually refers to the optimal amount of air that can make the fuel burn completely. For different types of fuels (such as gasoline, diesel, natural gas, etc.), their ideal air-fuel ratios may be different because of their different chemical compositions and reaction characteristics.

[0057] It is further important to know that the air-fuel ratio of the fuel is of great help in increasing the combustion temperature. This is because the fuel needs sufficient oxygen to burn completely when burning. Ensuring that the fuel can get enough oxygen is the key to increasing the combustion temperature.

[0058] The air-fuel ratio of the coal-fired boiler in the target period of each monitoring day is compared with the ideal air-fuel ratio to judge whether it is feasible to increase the combustion temperature by controlling the air-fuel ratio. The specific judgment is as follows: the air-fuel ratio of the coal-fired boiler in the target period of each monitoring day is compared with the ideal air-fuel ratio. Similarly, the air-fuel ratio control margin of the coal-fired boiler in the target period is calculated by referring to the combustion temperature control margin calculation method.

[0059] The air-fuel ratio control margin of the coal-fired boiler in the target period is compared with the set effective control margin. If the air-fuel ratio control margin of the coal-fired boiler in a certain target period is greater than the effective control margin, it is judged that it is feasible to increase the combustion temperature by controlling the air-fuel ratio. Otherwise, it is judged that it is not feasible to increase the combustion temperature by controlling the air-fuel ratio.

[0060] When it is judged that it is feasible to increase the combustion temperature by controlling the air-fuel ratio, the air-fuel ratio of the coal-fired boiler in the target period of each monitoring day is averaged and compared with the ideal air-fuel ratio. If the calculated result is less than the ideal air-fuel ratio, it usually means that the amount of air used for fuel combustion during the combustion process is insufficient. At this time, the adaptive execution method for increasing the combustion temperature is determined to be increasing the air supply. Otherwise, it means that the fuel used for fuel combustion during the combustion process is insufficient. At this time, the adaptive execution method for increasing the combustion temperature is determined to be reducing the fuel input. However, under normal circumstances, the air-fuel ratio will not be higher than the ideal air-fuel ratio. This is because the fuel input needs to meet the electricity demand, and thus the fuel input is usually sufficient.

[0061] Furthermore, it is determined that the adaptive execution method for increasing the combustion temperature is to optimize the air supply in combination with the fuel input density when increasing the air supply. The specific implementation is as follows: the volume of the furnace space of the coal-fired boiler is obtained, and the fuel input density is calculated in combination with the fuel input amount, and compared with the pre-configured limit input density. If the fuel input density is less than the limit input density, air supply is directly carried out, indicating that there is excess space for air supply. If the fuel input density is greater than or equal to the limit input density, it indicates that there is no excess space for air supply, and auxiliary air supply is performed at this time.

[0062] An exemplary auxiliary air supply may be to adjust the operating speed of a fan or a compressor, thereby improving the air-fuel ratio by increasing the flow rate and pressure of the air.

[0063] As another example, the auxiliary air supply may introduce an auxiliary oxidant (such as air preheated in an air preheater) to increase the oxygen content in the combustion chamber, thereby increasing the air-fuel ratio.

[0064] The present invention combines the fuel input density to operate when increasing the air supply to ensure the air-fuel ratio, so that the air supply can be increased more reasonably and in line with the actual situation, which is beneficial to improving the air supply effect.

[0065] In the innovative implementation of the above scheme, when it is judged that it is not feasible to increase the combustion temperature by controlling the air-fuel ratio, more efficient fuels can be used or the combustion performance of the fuel can be improved to increase the combustion temperature. For example, using dried fuel or adjusting the particle size and shape of the fuel can help improve its combustion efficiency and release more heat energy.

[0066] In another example of the above scheme, the mixing method of fuel and air can also be improved to increase the surface area of ​​contact between fuel and air, improve combustion efficiency and combustion temperature, and specifically optimize the fuel injection system or increase the premixed combustion area.

[0067] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the present invention, they should all fall within the protection scope of the present invention.

Claims

1. An intelligent combustion control method for a coal-fired boiler based on deep peak load regulation, characterized in that: The following steps are involved: Select a historical monitoring period, and divide the duration of each monitoring day in the historical monitoring period according to a set time interval to obtain a number of power consumption periods corresponding to each monitoring day; Extract the power consumption of each power consumption period on each monitoring day from the power consumption log of the power system, and extract the fuel consumption and combustion efficiency of each power consumption period on each monitoring day from the combustion records of the coal-fired boiler; The distribution difference analysis of the electricity consumption in the same electricity consumption period on each monitoring day is carried out to determine the effective electricity consumption in each electricity consumption period. Similarly, the distribution difference analysis of fuel consumption and combustion efficiency is carried out to obtain the effective fuel consumption and effective combustion efficiency in each electricity consumption period. A two-dimensional coordinate system is constructed with the power consumption period as the horizontal axis and the power consumption as the vertical axis, and a number of points are marked in the constructed two-dimensional coordinate system for the effective power consumption in each power consumption period to form a power consumption change curve. Similarly, a two-dimensional coordinate system is constructed with the power consumption period as the horizontal axis and the fuel consumption and combustion efficiency as the vertical axis, and a fuel consumption change curve and a combustion efficiency change curve are formed for the effective fuel consumption and effective combustion efficiency in each power consumption period; The power consumption change curve, the fuel consumption change curve, and the combustion efficiency change curve are used to identify abnormalities, and the power consumption period that requires combustion control is identified and recorded as the target period; Extract the combustion temperature during the target period of each monitoring day from the combustion records of the coal-fired boiler. And obtain the normal operating temperature range of the coal-fired boiler equipment, thereby determining the demand combustion control method of the coal-fired boiler in the target period; When the adaptive combustion control mode of the coal-fired boiler in the target period is to increase the combustion temperature, the air-fuel ratio of each monitoring day in the target period is extracted from the combustion record of the coal-fired boiler, thereby determining the adaptive execution mode of increasing the combustion temperature; The abnormal identification of the power consumption change curve, the fuel consumption change curve, and the combustion efficiency change curve is implemented as follows: Map the points in the power consumption change curve and the fuel consumption change curve to obtain the point group corresponding to each power consumption period; Compare the slope sign of the midpoint of the power consumption change curve of each power consumption period with the slope sign of the midpoint of the fuel consumption change curve, and select the same increase period; Compare the slope of the midpoint of the electricity consumption change curve during the same increase period with the slope of the midpoint of the fuel consumption change curve, and calculate the difference in growth rate corresponding to each period of same increase; Compare the growth rate difference corresponding to each period of same increase with the normal growth rate difference, and extract the period of same increase with a greater growth rate difference than the normal growth rate difference as the asynchronous period; The slope of the asynchronous period is extracted from the combustion efficiency change curve, and the identification model is , get the recognition result of whether the asynchronous period is abnormal, in the model Indicates an abnormality. Indicates that there is no abnormality. Indicates the slope of the asynchronous period in the combustion efficiency change curve. Indicates the set zero slope, , , Respectively represent and, or, and not; The identifying of the power consumption period that needs combustion control is specifically: selecting the asynchronous period with abnormality as the power consumption period that needs combustion control from the identification result of whether the asynchronous period is abnormal; The method for determining the demand combustion control of the coal-fired boiler in the target period is as follows: Extract the type of fuel used in the coal-fired boiler from the combustion record, and obtain the combustion temperature of the fuel in a complete combustion state as the ideal combustion temperature; Extract the upper limit operating temperature from the normal operating temperature range of the coal-fired boiler equipment, then compare the ideal combustion temperature with the upper limit operating temperature, and select the required combustion temperature; The combustion temperature of the coal-fired boiler during the target period of each monitoring day is compared with the required combustion temperature, and the expression , calculate the combustion temperature control margin of the coal-fired boiler during the target period , where Indicates that the coal-fired boiler Monitor combustion temperature during target periods during the day, Indicates the monitoring day number, , Indicates the number of monitoring days in the historical monitoring period. Indicates the required combustion temperature, represents a natural constant; Compare the combustion temperature control margin of the coal-fired boiler in the target period with the set effective control margin. If the combustion temperature control margin of the coal-fired boiler in a certain target period is greater than the effective control margin, the demand combustion control method of the coal-fired boiler in this target period is to increase the combustion temperature. Otherwise, the demand combustion control method of the coal-fired boiler in this target period is to extend the combustion time.

2. The method for intelligent combustion control of a coal-fired boiler based on deep peak load regulation according to claim 1, characterized in that: The distribution difference analysis of the power consumption in the same power consumption period on each monitoring day is shown in the following process: Compare the power consumption during the same power consumption period on each monitoring day, and select the highest and lowest power consumption; The power consumption of the same power consumption period on each monitoring day is averaged to obtain the average power consumption of each power consumption period; The maximum power consumption in each power consumption period is subtracted from the average power consumption to obtain the maximum-average power consumption difference, and the average power consumption is subtracted from the minimum power consumption to obtain the minimum-average power consumption difference; The difference between the highest and average power consumption in each power consumption period is subtracted from the difference between the lowest and average power consumption, and the absolute value of the difference result is divided by the sum of the highest power consumption and the lowest power consumption to obtain the power consumption distribution difference in each power consumption period.

3. The method for intelligent combustion control of a coal-fired boiler based on deep peak load regulation according to claim 2, characterized in that: The process of determining the effective power consumption in each power consumption period is as follows: The power consumption distribution difference of each power consumption period is compared with the set allowable difference. If the power consumption distribution difference of a certain power consumption period is greater than the allowable difference, the median power consumption of this power consumption period in each monitoring day is taken as the effective power consumption of this power consumption period; otherwise, the average power consumption of this power consumption period is taken as the effective power consumption of this power consumption period.

4. The method for intelligent combustion control of a coal-fired boiler based on deep peak load regulation according to claim 1, characterized in that: The required combustion temperature is selected as follows: The ideal combustion temperature is compared with the upper limit operating temperature. If the ideal combustion temperature is higher than the upper limit operating temperature, the upper limit operating temperature is used as the required combustion temperature. Otherwise, the ideal combustion temperature is used as the required combustion temperature.

5. The method for intelligent combustion control of a coal-fired boiler based on deep peak load regulation according to claim 1, characterized in that: The adaptive execution mode of determining the increase in combustion temperature is as follows: Get the ideal air-fuel ratio based on the type of fuel used in the coal-fired boiler; Compare the air-fuel ratio of the coal-fired boiler during the target period of each monitoring day with the ideal air-fuel ratio to determine whether it is feasible to increase the combustion temperature by controlling the air-fuel ratio; When it is judged that it is feasible to increase the combustion temperature by controlling the air-fuel ratio, the air-fuel ratio of the coal-fired boiler in the target period of each monitoring day is averaged and the calculated result is compared with the ideal air-fuel ratio. If the calculated result is less than the ideal air-fuel ratio, the adaptive execution method for increasing the combustion temperature is determined to be increasing the air supply; otherwise, the adaptive execution method for increasing the combustion temperature is determined to be reducing the fuel input.

6. The method for intelligent combustion control of a coal-fired boiler based on deep peak load regulation according to claim 5, characterized in that: The judgment of whether it is feasible to increase the combustion temperature by controlling the air-fuel ratio is as follows: Compare the air-fuel ratio of the coal-fired boiler during the target period of each monitoring day with the ideal air-fuel ratio, and similarly calculate the air-fuel ratio control margin of the coal-fired boiler during the target period; The air-fuel ratio control margin of the coal-fired boiler in the target period is compared with the set effective control margin. If the air-fuel ratio control margin of the coal-fired boiler in a certain target period is greater than the effective control margin, it is judged that it is feasible to increase the combustion temperature by controlling the air-fuel ratio. Otherwise, it is judged that it is not feasible to increase the combustion temperature by controlling the air-fuel ratio.

7. The method for intelligent combustion control of a coal-fired boiler based on deep peak load regulation according to claim 5, characterized in that: The adaptive execution mode of determining to increase the combustion temperature is to optimize the air supply in combination with the fuel input density when increasing the air supply, which is specifically performed as follows: The volume of the furnace space of the coal-fired boiler is obtained, and the fuel input density is calculated based on the fuel input amount, and compared with the pre-configured limit input density. If the fuel input density is less than the limit input density, air is directly supplied. If the fuel input density is greater than or equal to the limit input density, auxiliary air is supplied.

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