Ash clogging monitoring system and method for air preheater

Abstract

The invention provides an air pre-heater ash clogging monitoring system and method, and relates to the technical field of air pre-heaters, and the system comprises a real-time monitoring module which is used for obtaining real-time working parameters of an air pre-heater, and judging whether the ash clogging condition exists or not at present; and the ash clogging prediction module is used for performing ash clogging prediction according to the historical working parameters of the air preheater. The permissible fluctuation range of the flue gas pressure difference is updated regularly according to the real-time working parameters of the air preheater, flue gas emission can be more accurately controlled, accidental shutdown of the air preheater caused by improper parameter setting can be reduced, and therefore the stability and safety of operation of the whole device are improved, and the service life of the whole device is prolonged. When the flue gas pressure difference is changed abnormally, ash blocking prediction is carried out, prevention measures are taken before actual occurrence of ash blocking, actual occurrence of ash blocking is avoided, and stable operation of the air preheater is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of air preheaters, and in particular to an air preheater ash blockage monitoring system and method. Background Art

[0002] The air preheater is a heat exchange device that uses the heat of the flue gas at the tail of the boiler to heat the air required for fuel combustion to improve the efficiency of the boiler. However, during operation, the air preheater often has the problem of ash blockage (ash blockage), which affects the boiler efficiency and the benefits of the power plant.

[0003] The existing air preheater ash blockage monitoring system lacks the prediction of ash blockage and cannot take targeted preventive measures in advance to prevent the occurrence of ash blockage. Summary of the invention

[0004] The present invention provides an air preheater ash blockage monitoring system and method, which are used to solve the defects in the prior art that there is a lack of prediction of ash blockage and it is impossible to take targeted preventive measures to prevent the occurrence of ash blockage before ash blockage occurs.

[0005] In one aspect, the present invention provides an air preheater ash blocking monitoring system, comprising:

[0006] Real-time monitoring module, used to obtain the real-time working parameters of the air preheater and determine whether there is ash blockage at present;

[0007] The ash blockage prediction module is used to predict ash blockage based on the historical operating parameters of the air preheater.

[0008] Preferably, the operation monitoring module includes:

[0009] A data acquisition unit, used to obtain real-time operating parameters of the air preheater, the operating parameters including the flue gas pressure at the inlet and outlet of the air preheater, the flue gas temperature at the inlet of the air preheater, and the flue gas flow rate;

[0010] Detection and monitoring unit, used to regularly determine the operating status of the monitoring system of each working parameter;

[0011] A range setting unit, used to set the allowable fluctuation range of the flue gas pressure difference according to the design parameters and real-time working parameters of the air preheater, the flue gas pressure difference being the difference in flue gas pressure at the inlet and outlet of the air preheater;

[0012] The judgment unit determines that there is currently ash blockage when the actual flue gas pressure difference of the air preheater exceeds the allowable fluctuation range of the flue gas pressure difference, otherwise it determines that there is currently no ash blockage.

[0013] Preferably, the equipment monitoring unit comprises:

[0014] A parameter acquisition subunit, used for periodically acquiring all original detection data of the detection device within a first time range;

[0015] A data screening subunit, used for screening out normal data from the original detection data;

[0016] The status judgment subunit is used to calculate the status judgment parameter of the monitoring system corresponding to each working parameter and judge the operating status of the monitoring system;

[0017] Among them, A i M is the state judgment parameter of the monitoring system corresponding to the i-th working parameter; i is the total number of detection devices of the monitoring system corresponding to the i-th working parameter; S is the preset operation judgment threshold; Z ij N is the total number of normal data of the jth detection device of the monitoring system corresponding to the i-th working parameter; ij is the total number of original detection data of the jth detection device of the monitoring system corresponding to the i-th working parameter; is the rounding symbol;

[0018] When the state judgment parameter of the monitoring system is higher than the preset first judgment threshold, the operation state of the monitoring system is judged to be normal, otherwise the operation state of the monitoring system is judged to be faulty;

[0019] The alarm subunit will sound an alarm when any of the monitoring systems fails in operation.

[0020] Preferably, the range setting unit includes:

[0021] The upper limit adjustment subunit is used to calculate the allowable upper limit value of the flue gas pressure difference;

[0022] Among them, P max is the upper limit of the allowable flue gas pressure difference; P m0 is the maximum allowable flue gas pressure difference of the air preheater under design conditions; α and β are the influence coefficients of flue gas temperature and flue gas flow rate on the upper limit of the allowable flue gas pressure difference respectively; T rs is the actual flue gas temperature at the inlet of the air preheater; T rb is the standard flue gas temperature in the design condition at the inlet of the air preheater; Q rs is the actual flue gas flow rate at the inlet of the air preheater; Q rb is the standard flue gas flow rate in the design condition at the inlet of the air preheater;

[0023] The lower limit adjustment subunit is used to calculate the allowable lower limit value of the flue gas pressure difference;

[0024] P min =Pmax -P c ; Among them, P min P is the lower limit of the flue gas pressure difference; max P is the upper limit of the flue gas pressure difference; c It is the maximum allowable fluctuation value of the preset flue gas pressure difference;

[0025] The range setting subunit is used to generate an allowable fluctuation range of the flue gas pressure difference according to the allowable upper limit value and the allowable lower limit value of the flue gas pressure difference.

[0026] Preferably, the ash blockage prediction module includes:

[0027] The abnormal monitoring unit is used to monitor the changes in flue gas pressure difference. When the flue gas pressure difference changes abnormally, ash blockage prediction is performed;

[0028] The probability prediction unit is used to calculate the probability of ash blockage and determine whether ash blockage will occur. If the result of the determination is that ash blockage will occur, the predicted time of ash blockage is predicted.

[0029] A time prediction unit, used to predict the occurrence time of ash blockage;

[0030] The result output unit is used to give an alarm and output the predicted time of ash blockage when the judgment result of ash blockage prediction is that ash blockage will occur.

[0031] Preferably, the abnormal change of flue gas pressure difference includes: trend increase and abnormal fluctuation, and the abnormal monitoring unit includes:

[0032] The data calling subunit is used to call several groups of latest historical data of flue gas pressure difference;

[0033] The data sampling subunit is used to uniformly extract several groups of analysis data from the historical data of flue gas pressure difference;

[0034] A trend fitting subunit, used for drawing a scatter plot of pressure difference changes based on the analysis data and obtaining a pressure difference change trend line through fitting;

[0035] The trend judgment subunit determines that when the slope of any point on the pressure difference change trend line is greater than a preset slope threshold, it is determined that there is a trend increase, otherwise it is determined that there is no trend increase;

[0036] The fluctuation judgment subunit determines that abnormal fluctuation occurs when the difference between any two sets of adjacent analysis data is greater than a preset fluctuation threshold, otherwise it determines that abnormal fluctuation does not occur.

[0037] Preferably, the probability prediction unit includes:

[0038] The parameter acquisition subunit is used to obtain the ash blocking influencing parameters, which include: flue gas composition at the inlet of the air preheater, flue gas flow, flue gas temperature, flue gas pressure, and flue gas humidity;

[0039] The probability calculation subunit is used to calculate the probability of ash blockage;

[0040] Where D is the probability of ash blockage; e is a natural constant; ln is a logarithmic function with e as the base; C S is the sulfur content in flue gas; C S0 is the preset standard value of flue gas sulfur content; C A is the ash content in the flue gas; C A0 is the preset standard value of flue gas ash content; U s is the actual service life of the air preheater; U b Q is the design service life of the air preheater; rs is the actual flue gas flow rate at the inlet of the air preheater; Q rb is the standard flue gas flow rate under design conditions at the inlet of the air preheater; k 1 , k 2 , k 3 are the weighted coefficients of flue gas temperature, flue gas pressure and flue gas humidity at the inlet of air preheater; T rs is the actual flue gas temperature at the air preheater inlet; T 0 is the unit temperature; P r is the actual flue gas pressure at the inlet of the air preheater; P 0 is the unit pressure; H r is the actual flue gas humidity at the inlet of the air preheater; H rb is the standard flue gas humidity in the design condition at the inlet of the air preheater; H 0 is the unit humidity; P S is the current actual flue gas pressure difference; P max is the upper limit of the allowable flue gas pressure difference;

[0041] The ash blocking judgment subunit determines that ash blocking may occur when the probability of ash blocking is greater than a preset ash blocking judgment threshold, otherwise the judgment result is that ash blocking will not occur.

[0042] Preferably, the time prediction unit predicts the occurrence time of ash blockage based on the following formula:

[0043] Among them, t is the predicted occurrence time of ash blockage; P b is the preset dangerous smoke pressure difference threshold; P s is the current actual flue gas pressure difference; Q rs is the actual flue gas flow rate at the inlet of the air preheater; is the average flue gas flow rate of the analysis data; T rs is the actual flue gas temperature at the inlet of the air preheater; P r is the actual flue gas pressure at the inlet of the air preheater; H r is the actual flue gas humidity at the air preheater inlet; is the average flue gas temperature of the analyzed data; is the average flue gas pressure of the analyzed data; is the average smoke humidity of the analyzed data; W e It is the flue gas pressure difference change rate obtained according to the pressure difference change trend line.

[0044] On the other hand, the present invention further provides an air preheater ash blockage monitoring method, which is applied to the above-mentioned air preheater ash blockage monitoring system, comprising:

[0045] Step 1: Obtain the real-time flue gas pressure difference of the air preheater to determine whether there is ash blockage in the current air preheater;

[0046] Step 2: Regularly check the operating status of the reaming equipment;

[0047] Step 3: Regularly adjust the allowable fluctuation range of flue gas pressure difference;

[0048] Step 4: Conduct real-time detection of flue gas pressure difference. When the flue gas pressure difference changes abnormally, make ash blockage prediction;

[0049] Step 5: When the ash blockage prediction result indicates that ash blockage will occur, preventive measures are implemented within the predicted time of ash blockage.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] By regularly updating the allowable fluctuation range of the flue gas pressure difference according to the real-time operating parameters of the air preheater, it is helpful to control flue gas emissions more accurately and reduce unexpected shutdowns of the air preheater due to improper parameter settings, thereby improving the stability and safety of the overall equipment operation. When the flue gas pressure difference changes abnormally, by predicting ash blockage and taking preventive measures before ash blockage actually occurs, the actual occurrence of ash blockage can be avoided, thereby ensuring the stable operation of the air preheater. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 It is a structural schematic diagram of the air preheater ash blockage monitoring system of the present invention. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0055] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0056] Example 1

[0057] An embodiment of the present invention provides an air preheater ash blocking monitoring system, comprising:

[0058] Real-time monitoring module, used to obtain the real-time working parameters of the air preheater and determine whether there is ash blockage at present;

[0059] The ash blockage prediction module is used to predict ash blockage based on the historical operating parameters of the air preheater.

[0060] Preferably, the operation monitoring module includes:

[0061] A data acquisition unit, used to obtain real-time operating parameters of the air preheater, the operating parameters including the flue gas pressure at the inlet and outlet of the air preheater, the flue gas temperature at the inlet of the air preheater, and the flue gas flow rate;

[0062] Detection and monitoring unit, used to regularly determine the operating status of the monitoring system of each working parameter;

[0063] A range setting unit, used to set the allowable fluctuation range of the flue gas pressure difference according to the design parameters and real-time working parameters of the air preheater, the flue gas pressure difference being the difference in flue gas pressure at the inlet and outlet of the air preheater;

[0064] The judgment unit determines that there is currently ash blockage when the actual flue gas pressure difference of the air preheater exceeds the allowable fluctuation range of the flue gas pressure difference, otherwise it determines that there is currently no ash blockage.

[0065] Preferably, the equipment monitoring unit comprises:

[0066] A parameter acquisition subunit, used for periodically acquiring all original detection data of the detection device within a first time range;

[0067] A data screening subunit, used for screening out normal data from the original detection data;

[0068] The status judgment subunit is used to calculate the status judgment parameter of the monitoring system corresponding to each working parameter and judge the operating status of the monitoring system;

[0069] Among them, A i M is the state judgment parameter of the monitoring system corresponding to the i-th working parameter; i is the total number of detection devices of the monitoring system corresponding to the i-th working parameter; S is the preset operation judgment threshold; Z ij N is the total number of normal data of the jth detection device of the monitoring system corresponding to the i-th working parameter; ij is the total number of original detection data of the jth detection device of the monitoring system corresponding to the i-th working parameter; is the rounding symbol;

[0070] When the state judgment parameter of the monitoring system is higher than the preset first judgment threshold, the operation state of the monitoring system is judged to be normal, otherwise the operation state of the monitoring system is judged to be faulty;

[0071] The alarm subunit will sound an alarm when any of the monitoring systems fails in operation.

[0072] Preferably, the range setting unit includes:

[0073] The upper limit adjustment subunit is used to calculate the allowable upper limit value of the flue gas pressure difference;

[0074] Among them, P max P is the upper limit of the flue gas pressure difference; m0 is the maximum allowable flue gas pressure difference of the air preheater under design conditions; α and β are the influence coefficients of flue gas temperature and flue gas flow rate on the upper limit of the allowable flue gas pressure difference respectively; T rs is the actual flue gas temperature at the air preheater inlet; T rb is the standard flue gas temperature in the design condition at the inlet of the air preheater; Q rsis the actual flue gas flow rate at the inlet of the air preheater; Q rb is the standard flue gas flow rate in the design condition at the inlet of the air preheater;

[0075] The lower limit adjustment subunit is used to calculate the allowable lower limit value of the flue gas pressure difference;

[0076] P min =P max -P c ; Among them, P min P is the lower limit of the flue gas pressure difference; max is the upper limit of the allowable flue gas pressure difference; P c It is the maximum allowable fluctuation value of the preset flue gas pressure difference;

[0077] The range setting subunit is used to generate an allowable fluctuation range of the flue gas pressure difference according to the allowable upper limit value and the allowable lower limit value of the flue gas pressure difference.

[0078] In this embodiment, the first time range is the time range from a specified time length before the sampling time point to the sampling time point, such as the time range from five minutes before the sampling time point to the sampling time point, and the sampling time point is the time point for obtaining the original detection data.

[0079] In this embodiment, the original detection data refers to the most initial digital sample data obtained based on the sampling technology. It is the most basic and fundamental data without any modification, compilation or calculation.

[0080] In this embodiment, the detection system of the working parameters is a system composed of detection devices used to obtain the working parameters. For example, the detection system corresponding to the flue gas temperature is a temperature sensor group, and the detection device is a temperature sensor.

[0081] In this embodiment, normal data refers to data that conforms to expected behaviors, patterns, or standards in a specific data set or application scenario.

[0082] In this embodiment, the operation judgment threshold is a threshold set for judging whether the detection device is operating normally. When the proportion of normal data in the original detection data acquired by the detection device is greater than the operation judgment threshold, the detection device is judged to be operating normally.

[0083] In this embodiment, the influence coefficients of the flue gas temperature and the flue gas flow rate on the upper limit of the allowable flue gas pressure difference are obtained through simulation experiments.

[0084] The beneficial effects of the above technical solution are:

[0085] Regularly updating the allowable fluctuation range of flue gas pressure difference according to the real-time operating parameters of the air preheater helps to control flue gas emissions more accurately. By ensuring that the monitoring equipment operates under more accurate parameters, the deviation of monitoring data caused by equipment errors or improper parameter settings can be reduced. This helps to reduce unexpected shutdowns of air preheaters caused by improper parameter settings, thereby improving the stability and safety of overall equipment operation.

[0086] By regularly judging the operating status of the monitoring system, the stable operation of the monitoring system can be ensured. This can ensure that the monitoring system can provide sufficient monitoring data for the flue gas monitoring system, thereby ensuring the reliability of the monitoring data, and further ensuring the rationality of the adjustment of the allowable fluctuation range of the flue gas pressure difference, ultimately improving the operating stability of the flue gas monitoring system.

[0087] Example 2

[0088] Based on Example 1, the ash blocking prediction module includes:

[0089] The abnormal monitoring unit is used to monitor the changes in flue gas pressure difference. When the flue gas pressure difference changes abnormally, ash blockage prediction is performed;

[0090] The probability prediction unit is used to calculate the probability of ash blockage and determine whether ash blockage will occur. If the result of the determination is that ash blockage will occur, the predicted time of ash blockage is predicted.

[0091] A time prediction unit, used to predict the occurrence time of ash blockage;

[0092] The result output unit is used to give an alarm and output the predicted time of ash blockage when the judgment result of ash blockage prediction is that ash blockage will occur.

[0093] Preferably, the abnormal change of flue gas pressure difference includes: trend increase and abnormal fluctuation, and the abnormal monitoring unit includes:

[0094] The data calling subunit is used to call several groups of latest historical data of flue gas pressure difference;

[0095] The data sampling subunit is used to uniformly extract several groups of analysis data from the historical data of flue gas pressure difference;

[0096] A trend fitting subunit, used for drawing a scatter plot of pressure difference changes based on the analysis data and obtaining a pressure difference change trend line through fitting;

[0097] The trend judgment subunit determines that when the slope of any point on the pressure difference change trend line is greater than a preset slope threshold, it is determined that there is a trend increase, otherwise it is determined that there is no trend increase;

[0098] The fluctuation judgment subunit determines that abnormal fluctuation occurs when the difference between any two sets of adjacent analysis data is greater than a preset fluctuation threshold, otherwise it determines that abnormal fluctuation does not occur.

[0099] Preferably, the probability prediction unit includes:

[0100] The parameter acquisition subunit is used to obtain the ash blocking influencing parameters, which include: flue gas composition at the inlet of the air preheater, flue gas flow, flue gas temperature, flue gas pressure, and flue gas humidity;

[0101] The probability calculation subunit is used to calculate the probability of ash blockage;

[0102] Where D is the probability of ash blockage; e is a natural constant; ln is a logarithmic function with e as the base; C S is the sulfur content in flue gas; C S0 is the preset standard value of flue gas sulfur content; C A is the ash content in the flue gas; C A0 is the preset standard value of flue gas ash content; U s is the actual service life of the air preheater; U b Q is the design service life of the air preheater; rs is the actual flue gas flow rate at the inlet of the air preheater; Q rb is the standard flue gas flow rate under design conditions at the inlet of the air preheater; k 1 , k 2 , k 3 are the weighted coefficients of flue gas temperature, flue gas pressure and flue gas humidity at the inlet of air preheater; T rs is the actual flue gas temperature at the inlet of the air preheater; T 0 is the unit temperature; P r is the actual flue gas pressure at the inlet of the air preheater; P 0 is the unit pressure; H r is the actual flue gas humidity at the inlet of the air preheater; H rb is the standard flue gas humidity in the design condition at the inlet of the air preheater; H 0 is the unit humidity; P S is the current actual flue gas pressure difference; P max is the upper limit of the allowable flue gas pressure difference;

[0103] The ash blocking judgment subunit determines that ash blocking may occur when the probability of ash blocking is greater than a preset ash blocking judgment threshold, otherwise the judgment result is that ash blocking will not occur.

[0104] Preferably, the time prediction unit predicts the occurrence time of ash blockage based on the following formula:

[0105] Among them, t is the predicted occurrence time of ash blockage; P b is the preset dangerous smoke pressure difference threshold; P s is the current actual flue gas pressure difference; Q rs is the actual flue gas flow rate at the inlet of the air preheater; is the average flue gas flow rate of the analysis data; T rs is the actual flue gas temperature at the inlet of the air preheater; P r is the actual flue gas pressure at the inlet of the air preheater; H r is the actual flue gas humidity at the air preheater inlet; is the average flue gas temperature of the analyzed data; is the average flue gas pressure of the analyzed data; is the average smoke humidity of the analyzed data; W e It is the flue gas pressure difference change rate obtained according to the pressure difference change trend line.

[0106] In this embodiment, the ash blocking judgment threshold refers to a judgment threshold for judging whether ash blocking will occur. When the probability of ash blocking is higher than the ash blocking judgment threshold, the judgment result is that ash blocking will occur, otherwise the judgment result is that ash blocking will not occur.

[0107] In this embodiment, the standard value of the sulfur content in the flue gas is a theoretical value of the sulfur content in the flue gas entering the air preheater according to the design standard of the flue gas treatment system.

[0108] In this embodiment, the standard value of the flue gas ash content is a theoretical value of the ash content in the flue gas entering the air preheater according to the design standard of the flue gas treatment system.

[0109] In this embodiment, the influence weighting coefficients of the flue gas temperature, flue gas pressure and flue gas humidity at the air preheater inlet are obtained by fitting the simulation experimental data.

[0110] In this embodiment, the average flue gas pressure difference change speed is the slope at the end point of the pressure difference change trend line.

[0111] In this embodiment, the predicted occurrence time of ash blockage refers to the length of time until ash blockage occurs. For example, if the predicted occurrence time of ash blockage is 35 minutes, it means that ash blockage is expected to occur in 35 minutes.

[0112] The beneficial effects of the above technical solution are:

[0113] By monitoring the changes in flue gas pressure difference, when the flue gas pressure difference changes abnormally, the probability of ash blockage is calculated to determine whether ash blockage will occur in the future. When it is determined that ash blockage will occur in the future, the predicted time of ash blockage is predicted to ensure that timely measures are taken before ash blockage actually occurs to avoid the actual occurrence of ash blockage.

[0114] By calling the historical data of flue gas pressure difference and evenly extracting several groups of analysis data from the historical data, the amount of data processing is reduced, thereby improving the data processing speed. The pressure difference change trend line is obtained by fitting, so that the trend of pressure difference change can be more intuitively displayed. When the slope at any point of the pressure difference change trend line is greater than the preset slope threshold, it means that the rate of increase of the pressure difference is too large, which means that the air preheater may be blocked by ash. When the pressure difference fluctuates too much, it means that there is an unstable ash blockage inside the equipment, which also means that the air preheater may be blocked by ash.

[0115] When calculating the probability of ash blockage, the actual flue gas pressure difference is used to judge the current degree of unobstructedness inside the air preheater, so as to obtain the basic value of the probability of ash blockage. Then, the basic value of the probability of ash blockage is corrected by the flue gas properties at the inlet of the air preheater (including flue gas composition, flue gas flow, flue gas temperature, flue gas pressure, flue gas humidity) and the aging degree of the air preheater (the aging degree of the air preheater is inferred by the use time of the air preheater), so as to obtain the final probability of ash blockage, which improves the accuracy of the result of the probability of ash blockage. When the sulfur content in the flue gas is higher than the standard value, it will aggravate the dew point increase and condensation of sulfuric acid vapor, thereby increasing the probability of ash blockage. When the ash content in the flue gas is higher than the standard value, the ash will undergo complex chemical changes after absorbing sulfuric acid vapor, causing the ash layer to become hard and dense, which is more likely to cause ash blockage. When the flue gas flow rate increases, it will increase. The smoke content passing through the air preheater per unit time increases, thereby increasing the probability of ash blockage. When the flue gas temperature, flue gas pressure and flue gas humidity increase, it will cause the smoke to adhere more easily to the inside of the air preheater, thereby increasing the probability of ash blockage. By setting the ash blockage judgment threshold, it is determined whether ash blockage will occur, thereby providing an intuitive judgment basis for whether to predict the occurrence time of ash blockage. When it is determined that ash blockage will occur, the predicted occurrence time of ash blockage is predicted based on the analysis data. The difference between the current actual flue gas pressure difference and the flue gas pressure difference threshold corresponding to the occurrence of ash blockage is calculated, and then the change rate of the flue gas pressure difference corrected by the flue gas temperature, flue gas pressure and flue gas humidity is calculated to obtain the predicted occurrence time of ash blockage, thereby determining the executable time for executing the treatment measures, thereby ensuring that measures are taken in time before ash blockage actually occurs to avoid the actual occurrence of ash blockage.

[0116] Example 3

[0117] The embodiment of the present invention further provides an air preheater ash blockage monitoring method, comprising:

[0118] Step 1: Obtain the real-time flue gas pressure difference of the air preheater to determine whether there is ash blockage in the current air preheater;

[0119] Step 2: Regularly check the operating status of the reaming equipment;

[0120] Step 3: Regularly adjust the allowable fluctuation range of flue gas pressure difference;

[0121] Step 4: Conduct real-time detection of flue gas pressure difference. When the flue gas pressure difference changes abnormally, make ash blockage prediction;

[0122] Step 5: When the ash blockage prediction result indicates that ash blockage will occur, preventive measures are implemented within the predicted time of ash blockage.

[0123] The beneficial effects of the above technical solution are:

[0124] By regularly updating the allowable fluctuation range of the flue gas pressure difference according to the real-time operating parameters of the air preheater, it is helpful to control flue gas emissions more accurately and reduce unexpected shutdowns of the air preheater due to improper parameter settings, thereby improving the stability and safety of the overall equipment operation. When the flue gas pressure difference changes abnormally, by predicting ash blockage and taking preventive measures before ash blockage actually occurs, the actual occurrence of ash blockage can be avoided, thereby ensuring the stable operation of the air preheater.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An air preheater ash blocking monitoring system, characterized in that: include: Real-time monitoring module, used to obtain the real-time working parameters of the air preheater and determine whether there is ash blockage at present; The ash blockage prediction module is used to predict ash blockage based on the historical operating parameters of the air preheater.

2. The air preheater ash blockage monitoring system and method according to claim 1, characterized in that: The operation monitoring module includes: A data acquisition unit, used to obtain real-time operating parameters of the air preheater, the operating parameters including the flue gas pressure at the inlet and outlet of the air preheater, the flue gas temperature at the inlet of the air preheater, and the flue gas flow rate; Detection and monitoring unit, used to regularly determine the operating status of the monitoring system of each working parameter; A range setting unit, used to set the allowable fluctuation range of the flue gas pressure difference according to the design parameters and real-time working parameters of the air preheater, the flue gas pressure difference being the difference in flue gas pressure at the inlet and outlet of the air preheater; The judgment unit determines that there is currently ash blockage when the actual flue gas pressure difference of the air preheater exceeds the allowable fluctuation range of the flue gas pressure difference, otherwise it determines that there is currently no ash blockage.

3. The air preheater ash blockage monitoring system and method according to claim 2, characterized in that: The equipment monitoring unit includes: A parameter acquisition subunit, used for periodically acquiring all original detection data of the detection device within a first time range; A data screening subunit, used for screening out normal data from the original detection data; The status judgment subunit is used to calculate the status judgment parameter of the monitoring system corresponding to each working parameter and judge the operating status of the monitoring system; Among them, A i M is the state judgment parameter of the monitoring system corresponding to the i-th working parameter; i is the total number of detection devices of the monitoring system corresponding to the i-th working parameter; S is the preset operation judgment threshold; Z ij N is the total number of normal data of the jth detection device of the monitoring system corresponding to the i-th working parameter; ij is the total number of original detection data of the jth detection device of the monitoring system corresponding to the i-th working parameter; is the rounding symbol; When the state judgment parameter of the monitoring system is higher than the preset first judgment threshold, the operation state of the monitoring system is judged to be normal, otherwise the operation state of the monitoring system is judged to be faulty; The alarm subunit will sound an alarm when any of the monitoring systems fails in operation.

4. The air preheater ash blockage monitoring system and method according to claim 2, characterized in that: The scope setting unit includes: The upper limit adjustment subunit is used to calculate the allowable upper limit value of the flue gas pressure difference; Among them, P max is the upper limit of the allowable flue gas pressure difference; P m0 is the maximum allowable flue gas pressure difference of the air preheater under design conditions; α and β are the influence coefficients of flue gas temperature and flue gas flow rate on the upper limit of the allowable flue gas pressure difference respectively; T rs is the actual flue gas temperature at the inlet of the air preheater; T rb is the standard flue gas temperature in the design condition at the inlet of the air preheater; Q rs is the actual flue gas flow rate at the inlet of the air preheater; Q rb is the standard flue gas flow rate in the design condition at the inlet of the air preheater; The lower limit adjustment subunit is used to calculate the allowable lower limit value of the flue gas pressure difference; P min =P max -P c ; Among them, P min is the lower limit of the flue gas pressure difference; P max is the upper limit of the allowable flue gas pressure difference; P c It is the maximum allowable fluctuation value of the preset flue gas pressure difference; The range setting subunit is used to generate an allowable fluctuation range of the flue gas pressure difference according to the allowable upper limit value and the allowable lower limit value of the flue gas pressure difference.

5. The air preheater ash blockage monitoring system and method according to claim 1, characterized in that: The ash blockage prediction module includes: The abnormal monitoring unit is used to monitor the changes in flue gas pressure difference. When the flue gas pressure difference changes abnormally, ash blockage prediction is performed; The probability prediction unit is used to calculate the probability of ash blockage and determine whether ash blockage will occur. If the result of the determination is that ash blockage will occur, the predicted time of ash blockage is predicted. A time prediction unit, used to predict the occurrence time of ash blockage; The result output unit is used to give an alarm and output the predicted time of ash blockage when the judgment result of ash blockage prediction is that ash blockage will occur.

6. The air preheater ash blockage monitoring system and method according to claim 5, characterized in that: Abnormal changes in flue gas pressure difference include: trend increase and abnormal fluctuation. The abnormal monitoring units include: The data calling subunit is used to call several groups of latest historical data of flue gas pressure difference; The data sampling subunit is used to uniformly extract several groups of analysis data from the historical data of flue gas pressure difference; A trend fitting subunit, used for drawing a scatter plot of pressure difference changes based on the analysis data and obtaining a pressure difference change trend line through fitting; The trend judgment subunit determines that when the slope of any point on the pressure difference change trend line is greater than a preset slope threshold, it is determined that there is a trend increase, otherwise it is determined that there is no trend increase; The fluctuation judgment subunit determines that abnormal fluctuation occurs when the difference between any two sets of adjacent analysis data is greater than a preset fluctuation threshold, otherwise it determines that abnormal fluctuation does not occur.

7. The air preheater ash blockage monitoring system and method according to claim 5, characterized in that: The probability prediction unit includes: The parameter acquisition subunit is used to obtain the ash blocking influencing parameters, which include: flue gas composition at the inlet of the air preheater, flue gas flow, flue gas temperature, flue gas pressure, and flue gas humidity; The probability calculation subunit is used to calculate the probability of ash blockage; Where D is the probability of ash blockage; e is a natural constant; ln is a logarithmic function with e as the base; C S is the sulfur content in flue gas; C S0 is the preset standard value of flue gas sulfur content; C A is the ash content in the flue gas; C A0 is the preset standard value of flue gas ash content; U s is the actual service life of the air preheater; U b Q is the design service life of the air preheater; rs is the actual flue gas flow rate at the inlet of the air preheater; Q rb is the standard flue gas flow rate in the design conditions at the inlet of the air preheater; k1, k2, k3 are the weighted coefficients of the flue gas temperature, flue gas pressure and flue gas humidity at the inlet of the air preheater respectively; T rs is the actual flue gas temperature at the inlet of the air preheater; T0 is the unit temperature; P r is the actual flue gas pressure at the inlet of the air preheater; P0 is the unit pressure; H r is the actual flue gas humidity at the inlet of the air preheater; H rb is the standard flue gas humidity in the design conditions at the inlet of the air preheater; H0 is the unit humidity; P S is the current actual flue gas pressure difference; P max is the upper limit of the allowable flue gas pressure difference; The ash blocking judgment subunit determines that ash blocking may occur when the probability of ash blocking is greater than a preset ash blocking judgment threshold, otherwise the judgment result is that ash blocking will not occur.

8. The air preheater ash blockage monitoring system and method according to claim 5, characterized in that: The time prediction unit predicts the occurrence time of ash blockage based on the following formula: Among them, t is the predicted occurrence time of ash blockage; P b is the preset dangerous smoke pressure difference threshold; P s is the current actual flue gas pressure difference; Q rs is the actual flue gas flow rate at the inlet of the air preheater; is the average flue gas flow rate of the analysis data; T rs is the actual flue gas temperature at the inlet of the air preheater; P r is the actual flue gas pressure at the inlet of the air preheater; H r is the actual flue gas humidity at the air preheater inlet; is the average flue gas temperature of the analyzed data; is the average flue gas pressure of the analyzed data; is the average smoke humidity of the analyzed data; W e It is the flue gas pressure difference change rate obtained according to the pressure difference change trend line.

9. An air preheater ash blockage monitoring method, applied to an air preheater ash blockage monitoring system as claimed in any one of claims 1 to 8, characterized in that: include: Step 1: Obtain the real-time flue gas pressure difference of the air preheater to determine whether there is ash blockage in the current air preheater; Step 2: Regularly check the operating status of the reaming equipment; Step 3: Regularly adjust the allowable fluctuation range of flue gas pressure difference; Step 4: Conduct real-time detection of flue gas pressure difference. When the flue gas pressure difference changes abnormally, make ash blockage prediction; Step 5: When the ash blockage prediction result indicates that ash blockage will occur, preventive measures are implemented within the predicted time of ash blockage.

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