A boiler warning method under low load conditions

Abstract

A boiler warning method under low-load conditions disclosed in this application relates to the technical field of power plant equipment management, including analyzing flue gas components at different times to generate several corresponding component groups; constructing an air volume change curve for the real-time air volume of different air ducts, generating a pulverized coal change curve for the real-time pulverized coal injection volume, associating the corresponding time nodes of the component groups with the air volume change curve and the pulverized coal change curve, intercepting the air volume change characteristic segments and pulverized coal change characteristic segments before and after the time nodes, and using the component groups as the retrieval object to determine the standard air volume change characteristics and pulverized coal standard change characteristics in the preset combustion quality judgment rules, and respectively comparing and analyzing them with the air volume change characteristic segments and pulverized coal change characteristic segments, so as to determine the state of the combustion situation in the boiler.

Description

Technical Field

[0001] The present invention relates to the technical field of power plant equipment management, and particularly to a boiler warning method under low load conditions. Background Art

[0002] Conventional power plants are all equipped with boilers. The boiler is the steam-water system of the boiler, which consists of a economizer, water wall, superheater and reheater. Its main task is to make water absorb heat and evaporate, and finally become qualified superheated steam with certain parameters. The process is as follows: Feed water is pumped to the economizer by a feed water pump, gradually heated up, separated into steam and water and then enters the steam drum, enters the water wall through the downcomer and lower header, and continues to circulate and absorb heat in the water wall to become a steam-water mixture. The steam separated by the steam separator continues to pass through the roof tube superheater, wall superheater, low-temperature superheater, platen superheater and high-temperature superheater to become qualified superheated steam with certain pressure and temperature, and is sent to the steam turbine; After the high-pressure superheated steam does work in the high-pressure cylinder of the steam turbine, it is sent to the boiler reheater through the steam guide pipe for reheating, and then enters the intermediate and low-pressure cylinders of the steam turbine to continue to do work.

[0003] When the boiler enters the low load operating state, due to a certain degree of wear of some burners, and the previously introduced combustion air volume cannot accurately match the combustion intensity, which leads to combustion disturbance and unstable combustion of the burner combustion condition. In this case, since the combustion flame is in an unstable state, it will cause damage to other components in the boiler. In order to avoid the above problems, there is an urgent need for a warning method for the boiler to avoid damage to the boiler. Summary of the Invention

[0004] The purpose of the present invention is to provide a warning method for the boiler under low load conditions.

[0005] Therefore, the present invention discloses a boiler warning method under low load conditions, including:

[0006] Obtain the flue gas discharged by the boiler in real time, analyze the components in the flue gas at different times, and generate several corresponding groups of components;

[0007] Obtain the real-time combustion air volume injection information, and determine the real-time air volume of different air ducts of the burner according to the real-time combustion air volume injection information, and construct an air volume change curve for different air ducts of the burner according to the real-time air volume. The ordinate of the air volume change curve is the real-time air volume, and the abscissa is time;

[0008] Obtain the real-time pulverized coal injection amount, and generate a pulverized coal change curve according to the real-time pulverized coal injection amount. The ordinate of the pulverized coal change curve is the real-time pulverized coal injection amount, and the abscissa is time;

[0009] Associate the corresponding component groups with the corresponding time nodes in the air volume change curve and the pulverized coal change curve, and intercept the characteristic segments before and after the time nodes on the air volume change curve and the pulverized coal change curve to generate an air volume change characteristic segment and a pulverized coal change characteristic segment respectively;

[0010] Analyze the corresponding component groups according to the preset combustion quality judgment rules to determine the standard air volume change characteristics and the standard pulverized coal change characteristics;

[0011] Compare and analyze the marked air volume change characteristics with the air volume change characteristic segment, and determine the first risk assessment factor according to the difference characteristics;

[0012] Compare and analyze the standard pulverized coal change characteristics with the pulverized coal change characteristic segment, and determine the second risk assessment factor according to the difference characteristics;

[0013] Classify and alarm the operating state of the boiler according to the first risk assessment factor and the second risk assessment factor.

[0014] In some embodiments of the present application, in order to be able to determine the marked air volume change characteristics and the standard pulverized coal change characteristics, the content of the preset combustion quality judgment rules is disclosed. The content of the preset combustion quality judgment rules includes: several preset component corresponding groups, the preset component corresponding groups include the content of all components in the flue gas at the same moment, and each preset component corresponding group corresponds to specific standard pulverized coal change characteristics and standard air volume change characteristics.

[0015] In some embodiments of the present application, in order to be able to analyze the corresponding component groups, a method of applying the preset combustion quality judgment rules is disclosed. The method of analyzing the corresponding component groups according to the preset combustion quality judgment rules includes:

[0016] Compare and analyze the corresponding component groups with several preset component corresponding groups in the preset combustion quality judgment rules to determine the preset component corresponding group with the lowest degree of difference;

[0017] According to the determined preset component corresponding group, determine the corresponding standard pulverized coal change characteristics and standard air volume change characteristics in the preset combustion quality judgment rules.

[0018] In some embodiments of the present application, in order to be able to determine the required standard pulverized coal change characteristics and standard air volume change characteristics in the preset combustion quality judgment rules, a method of determining the preset component corresponding group with the lowest degree of difference from the corresponding component groups is disclosed. The method of determining the preset component corresponding group with the lowest degree of difference includes:

[0019] Calculate the content difference of the corresponding components in the component corresponding group and the preset component corresponding group. If there is no content difference greater than the preset value, sum up the absolute values of the content differences to obtain the corresponding value of the degree of difference;

[0020] The expression for determining the corresponding value of the degree of difference is:

[0021]

[0022] where Y is the corresponding value of the degree of difference, n is the serial number corresponding to different components, a n is the content value of the component with serial number n in the component corresponding group, and b n is the content value of the component with serial number n in the preset component corresponding group.

[0023] In some embodiments of the present application, the specific content of the air volume change characteristics is disclosed. The air volume change characteristics include: several air duct change characteristic groups. The air duct change characteristic group is a set of air volume records for a single air duct, and the air duct change characteristic group includes several first preset air volumes separated by a first preset time interval.

[0024] In some embodiments of the present application, in order to determine the first risk assessment factor, a method for determining the first risk assessment factor is disclosed. The method for determining the first risk assessment factor includes:

[0025] Extract several first real-time air volumes from the air volume change characteristic segment at the first preset time interval, and compare and analyze the first real-time air volumes with the first preset air volumes;

[0026] If the difference between one of the first real-time air volumes and one of the first preset air volumes is greater than the preset value, it is determined that the air volume change is abnormal;

[0027] The corresponding value of the first risk assessment factor is the number of abnormal air volume changes.

[0028] In some embodiments of the present application, the specific content of the pulverized coal change characteristics is disclosed. The pulverized coal change characteristics include several first preset pulverized coal injection amounts separated by a second preset time interval.

[0029] In some embodiments of the present application, in order to determine the second risk assessment factor, a method for determining the second risk assessment factor is disclosed. The method for determining the second risk assessment factor includes:

[0030] Extract several first real-time pulverized coal injection amounts from the pulverized coal change characteristic segment at the second preset time interval, and compare and analyze the first real-time pulverized coal injection amounts with the first preset pulverized coal injection amounts;

[0031] If the difference between a first real-time pulverized coal injection amount and a first preset pulverized coal injection amount is greater than a preset value, it is determined that there is an abnormality in one-time pulverized coal injection;

[0032] The corresponding value of the second risk assessment factor is the number of times of abnormal pulverized coal injection.

[0033] In some embodiments of the present application, in order to be able to perform hierarchical alarm on a boiler, a specific method for performing hierarchical alarm on a boiler is disclosed. The method for performing hierarchical alarm on a boiler includes:

[0034] Establish an alarm level correspondence table, where the alarm level correspondence table includes several alarm levels, and each alarm level corresponds to a specific first risk assessment factor range and a specific second risk assessment factor range;

[0035] Obtain the first risk assessment factor and the second risk assessment factor, and compare and analyze the first risk assessment factor and the second risk assessment factor with the content of the alarm level correspondence table to determine the first risk assessment factor range to which the first risk assessment factor belongs and the second risk assessment factor range to which the second risk assessment factor belongs, and then determine the corresponding alarm level.

[0036] The present application discloses a boiler early warning method under low load conditions. The benefits of applying the early warning method of the present application are as follows:

[0037] 1. Analyze the flue gas components at different times to generate several component corresponding groups; for the real-time air volume of different air ducts, construct an air volume change curve, and for the real-time pulverized coal injection amount, generate a pulverized coal change curve. Associate the time nodes corresponding to the component corresponding groups, the air volume change curve, and the pulverized coal change curve, and intercept the air volume change characteristic section and the pulverized coal change characteristic section before and after the time node. Take the component corresponding group as the retrieval object, determine the air volume standard change characteristic and the pulverized coal standard change characteristic in the preset combustion quality judgment rule, and compare and analyze them with the air volume change characteristic section and the pulverized coal change characteristic section respectively, and then determine the state of the combustion situation in the boiler.

[0038] 2. Based on the analysis results of the air volume change characteristic section and the pulverized coal change characteristic section, determine the first risk assessment factor and the second risk assessment factor, and determine the internal combustion state of the boiler through the information expressed by the two risk assessment factors, and then perform hierarchical alarm on the boiler state.

[0039] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0040] Figure 1This is a method step diagram of a boiler warning method under low load conditions in an embodiment of the present application. Detailed implementation manners

[0041] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and should not be construed as limiting the protection scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments according to the content of the present invention below. In the present invention, unless otherwise clearly defined and limited, the technical terms used in this application should be the common meanings understood by those skilled in the art of the present invention. Terms such as "connected", "connected", "fixed", "set", etc. should be understood in a broad sense. It can be a fixed connection, a detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium; it can be a mechanical connection or an electrical connection. Unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature being "above" or "over" or "on" the second feature can be directly above or obliquely above the second feature, or merely indicate that the first feature has a higher horizontal height than the second feature. The first feature being "under" or "below" or "beneath" the second feature can be directly below or obliquely below the second feature, or merely indicate that the first feature has a lower horizontal height than the second feature. Relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0043] Embodiment:

[0044] The purpose of the present invention is to provide a warning method under the low load state of a boiler.

[0045] Therefore, the present invention discloses a boiler warning method under low load conditions. Refer to Figure 1 , including:

[0046] Step S100: Obtain the flue gas discharged by the boiler in real time, analyze the components in the flue gas at different times, and generate several corresponding groups of components.

[0047] Step S200: Obtain real-time combustion air injection information, determine the real-time air volume of different air ducts of the burner according to the real-time combustion air injection information, and construct an air volume change curve for different air ducts of the burner according to the real-time air volume. The ordinate of the air volume change curve is the real-time air volume, and the abscissa is time.

[0048] It should be understood that the real-time combustion air injection information includes the injection air volume provided to each air duct of the burner. Specifically, it is the operating power of the fan corresponding to different air ducts.

[0049] Step S300: Obtain the real-time pulverized coal injection amount, and generate a pulverized coal change curve according to the real-time pulverized coal injection amount. The ordinate of the pulverized coal change curve is the real-time pulverized coal injection amount, and the abscissa is time.

[0050] It should be understood that the real-time pulverized coal injection amount is the injection amount of pulverized coal fed into the burner.

[0051] Step S400: Associate the component corresponding group with the corresponding time nodes in the air volume change curve and the pulverized coal change curve, and intercept the characteristic segments before and after the time nodes on the air volume change curve and the pulverized coal change curve to generate an air volume change characteristic segment and a pulverized coal change characteristic segment respectively.

[0052] Step S500: Analyze the component corresponding group according to the preset combustion quality judgment rule to determine the standard air volume change characteristic and the standard pulverized coal change characteristic.

[0053] It should be understood that the preset combustion quality judgment rule is a judgment rule for the combustion situation of the burner in the boiler established for the flue gas components. Specifically, under the condition that the burner is not worn and there is no abnormality in the combustion in the boiler, the ideal values of the air outlet situation and the pulverized coal input situation of the burner are determined for the same flue gas component. The specific corresponding relationship can be obtained by experts through calculation.

[0054] Step S600: Compare and analyze the air volume standard change characteristic with the air volume change characteristic segment, and determine the first risk evaluation factor according to the difference characteristics.

[0055] Step S700: Compare and analyze the pulverized coal standard change characteristic with the pulverized coal change characteristic segment, and determine the second risk evaluation factor according to the difference characteristics.

[0056] Step S800: Classify and alarm the operating state of the boiler according to the first risk evaluation factor and the second risk evaluation factor.

[0057] In some embodiments of the present application, in order to be able to determine the variation characteristics of the air volume label and the variation characteristics of the pulverized coal standard, the content of the preset combustion quality judgment rule is disclosed. The content of the preset combustion quality judgment rule includes: several preset component corresponding groups, and each preset component corresponding group includes the content of all components in the flue gas at the same moment. Each preset component corresponding group corresponds to a specific pulverized coal standard variation characteristic and an air volume standard variation characteristic.

[0058] In some embodiments of the present application, in order to be able to analyze the component corresponding group, a method of applying the preset combustion quality judgment rule is disclosed. The method of analyzing the component corresponding group according to the preset combustion quality judgment rule includes:

[0059] First step, compare and analyze the component corresponding group with several preset component corresponding groups in the preset combustion quality judgment rule to determine the preset component corresponding group with the lowest degree of difference.

[0060] Second step, according to the determined preset component corresponding group, determine the corresponding pulverized coal standard variation characteristic and air volume standard variation characteristic in the preset combustion quality judgment rule.

[0061] In some embodiments of the present application, in order to be able to determine the required pulverized coal standard variation characteristic and air volume standard variation characteristic in the preset combustion quality judgment rule, a method of determining the preset component corresponding group with the lowest degree of difference from the component corresponding group is disclosed. The method of determining the preset component corresponding group with the lowest degree of difference includes: calculate the content difference of the corresponding components in the component corresponding group and the preset component corresponding group. If there is no content difference greater than the preset value, then accumulate and sum the absolute values of the content differences to obtain the corresponding value of the degree of difference;

[0062] It should be understood that if there is a situation where a certain content difference is greater than the preset value, it is considered that there may be two situations of positive and negative for the corresponding content differences in the component corresponding group and the preset component corresponding group, which may lead to a certain content difference being greater than the preset value. This situation obviously belongs to the excessive difference in the component content between the component corresponding group and the preset component corresponding group and should be excluded.

[0063] The expression for determining the corresponding value of the degree of difference is:

[0064]

[0065] where Y is the corresponding value of the degree of difference, n is the serial number corresponding to different components, a n is the content value of the component with serial number n in the component corresponding group, b nIt is the content value of the component with the serial number n in the corresponding group of the preset components.

[0066] In some embodiments of the present application, the specific content of the air volume change characteristics is disclosed. The air volume change characteristics include: several air duct change characteristic groups. The air duct change characteristic group is a set of air volume records for a single air duct, and the air duct change characteristic group includes several first preset air volumes separated by a first preset time interval.

[0067] In some embodiments of the present application, in order to be able to determine the first risk assessment factor, a method for determining the first risk assessment factor is disclosed. The method for determining the first risk assessment factor includes:

[0068] In the first step, several first real-time air volumes are intercepted from the air volume change characteristic segment at the first preset time interval, and the first real-time air volumes are compared and analyzed with the first preset air volumes.

[0069] In the second step, if the difference between one of the first real-time air volumes and one of the first preset air volumes is greater than the preset value, it is determined that there is an abnormal air volume change once.

[0070] In the third step, the corresponding value of the first risk assessment factor is the number of abnormal air volume changes.

[0071] In some embodiments of the present application, the specific content of the pulverized coal change characteristics is disclosed. The pulverized coal change characteristics include several first preset pulverized coal injection amounts separated by a second preset time interval.

[0072] In some embodiments of the present application, in order to be able to determine the second risk assessment factor, a method for determining the second risk assessment factor is disclosed. The method for determining the second risk assessment factor includes:

[0073] In the first step, several first real-time pulverized coal injection amounts are intercepted from the pulverized coal change characteristic segment at the second preset time interval, and the first real-time pulverized coal injection amounts are compared and analyzed with the first preset pulverized coal injection amounts.

[0074] In the second step, if the difference between one of the first real-time pulverized coal injection amounts and one of the first preset pulverized coal injection amounts is greater than the preset value, it is determined that there is an abnormal pulverized coal injection once.

[0075] The corresponding value of the second risk assessment factor is the number of abnormal pulverized coal injections.

[0076] In some embodiments of the present application, in order to be able to perform hierarchical alarm on the boiler, a specific method for performing hierarchical alarm on the boiler is disclosed. The method for performing hierarchical alarm on the boiler includes:

[0077] First step, establish an alarm level correspondence table, where the alarm level correspondence table includes several alarm levels, and each alarm level corresponds to a specific first risk assessment factor range and a specific second risk assessment factor range.

[0078] Second step, obtain the first risk assessment factor and the second risk assessment factor, and compare and analyze the first risk assessment factor and the second risk assessment factor with the content of the alarm level correspondence table to determine the first risk assessment factor range to which the first risk assessment factor belongs and the second risk assessment factor range to which the second risk assessment factor belongs, and then determine the corresponding alarm level.

[0079] This application discloses a boiler early warning method under low load conditions. The benefits of applying the early warning method of this application are as follows:

[0080] 1. Analyze the flue gas components at different times to generate several component corresponding groups; construct an air volume change curve for the real-time air volume of different air ducts, generate a pulverized coal change curve for the real-time pulverized coal injection volume, associate the time nodes corresponding to the component corresponding groups, the air volume change curve, and the pulverized coal change curve, intercept the air volume change characteristic segments and pulverized coal change characteristic segments before and after the time nodes, and use the component corresponding groups as the retrieval object to determine the standard air volume change characteristics and pulverized coal standard change characteristics in the preset combustion quality judgment rules, and compare and analyze them with the air volume change characteristic segments and pulverized coal change characteristic segments respectively, and then determine the state of the combustion situation in the boiler.

[0081] 2. Determine the first risk assessment factor and the second risk assessment factor based on the analysis results of the air volume change characteristic segments and the pulverized coal change characteristic segments, and determine the internal combustion state of the boiler through the information expressed by the two risk assessment factors, and then classify and alarm the boiler state.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A boiler warning method under low load conditions, characterized in that, Including: Obtain the flue gas discharged by the boiler in real time, analyze the components in the flue gas at different times, and generate several corresponding groups of components; Obtain the real-time combustion air volume injection information, determine the real-time air volume of different air ducts of the burner according to the real-time combustion air volume injection information, and construct an air volume change curve for different air ducts of the burner according to the real-time air volume. The ordinate of the air volume change curve is the real-time air volume, and the abscissa is time; Obtain the real-time pulverized coal injection volume, and generate a pulverized coal change curve according to the real-time pulverized coal injection volume. The ordinate of the pulverized coal change curve is the real-time pulverized coal injection volume, and the abscissa is time; Associate the corresponding group of components with the corresponding time nodes in the air volume change curve and the pulverized coal change curve, and intercept the characteristic segments before and after the time nodes on the air volume change curve and the pulverized coal change curve to generate an air volume change characteristic segment and a pulverized coal change characteristic segment respectively; Analyze the corresponding group of components according to the preset combustion quality judgment rule to determine the standard air volume change characteristic and the standard pulverized coal change characteristic; Compare and analyze the marked air volume change characteristic with the air volume change characteristic segment, and determine the first risk evaluation factor according to the difference characteristic; Compare and analyze the standard pulverized coal change characteristic with the pulverized coal change characteristic segment, and determine the second risk evaluation factor according to the difference characteristic; Perform hierarchical alarm on the operation state of the boiler according to the first risk evaluation factor and the second risk evaluation factor; The content of the preset combustion quality judgment rule includes: several preset corresponding groups of components, the preset corresponding groups of components include the content of all components in the flue gas at the same moment, and each preset corresponding group of components corresponds to a specific standard pulverized coal change characteristic and a standard air volume change characteristic; The method for analyzing the corresponding group of components according to the preset combustion quality judgment rule includes: Compare and analyze the corresponding group of components with several preset corresponding groups of components in the preset combustion quality judgment rule to determine the preset corresponding group of components with the lowest degree of difference; According to the determined preset corresponding group of components, determine the corresponding standard pulverized coal change characteristic and standard air volume change characteristic in the preset combustion quality judgment rule; The air volume change characteristic includes: several air duct change characteristic groups, the air duct change characteristic group is a set of air volume records for a single air duct, and the air duct change characteristic group includes several first preset air volumes separated by a first preset time interval; The method for determining the first risk evaluation factor includes: Intercept several first real-time air volumes from the air volume change characteristic segment at the first preset time interval, and compare and analyze the first real-time air volumes with the first preset air volumes; If the difference between one of the first real-time air volumes and one of the first preset air volumes is greater than the preset value, it is determined that the air volume change is abnormal once; The corresponding value of the first risk evaluation factor is the number of abnormal air volume changes; The pulverized coal change characteristic includes several first preset pulverized coal injection volumes separated by a second preset time interval; The method for determining the second risk evaluation factor includes: Extract a number of first real-time pulverized coal injection amounts from the pulverized coal change characteristic section at the second preset time interval, and compare and analyze the first real-time pulverized coal injection amounts with the first preset pulverized coal injection amounts; If the difference between one of the first real-time pulverized coal injection amounts and one of the first preset pulverized coal injection amounts is greater than the preset value, it is determined as an abnormal pulverized coal injection; The corresponding value of the second risk assessment factor is the number of abnormal pulverized coal injections.

2. The boiler warning method under low load conditions according to claim 1, wherein The method for determining the preset component corresponding group with the lowest degree of difference includes: Calculate the content difference of the corresponding components in the component corresponding group and the preset component corresponding group. If there is no content difference greater than the preset value, sum up the absolute values of the content differences to obtain the corresponding value of the degree of difference; The expression for determining the corresponding value of the degree of difference is: Among them, Y is the corresponding value of the degree of difference, n is the serial number corresponding to different components, and a n is the content value of the component b with the serial number n in the corresponding group of the component, and is the content value of the component with the serial number n in the corresponding group of the preset component. n ​ 3. A boiler warning method under low load conditions according to claim 1, characterized in that, The method for grading and alarming the boiler includes: Establish an alarm level correspondence table, which includes several alarm levels, and each alarm level corresponds to a specific first risk assessment factor range and a specific second risk assessment factor range; Obtain the first risk assessment factor and the second risk assessment factor, and compare and analyze the first risk assessment factor and the second risk assessment factor with the content of the alarm level correspondence table to determine the first risk assessment factor range to which the first risk assessment factor belongs and the second risk assessment factor range to which the second risk assessment factor belongs, and then determine the corresponding alarm level.

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