A waste gas purification system with intelligent temperature control and pressure monitoring

Abstract

The present application relates to the technical field of waste gas purification control, and specifically discloses a waste gas purification system with intelligent temperature control and pressure monitoring, which analyzes the temperature variation of waste gas in the waste gas conveying pipeline during the fluctuation overlapping period, evaluates whether there is a lag phenomenon between the waste gas temperature fluctuation and the waste gas pressure fluctuation, determines the fluctuation lag period, constructs a temperature-pressure lag fitting line if there is a lag phenomenon between the waste gas temperature fluctuation and the waste gas pressure fluctuation, analyzes the temperature-pressure lag fitting line, evaluates whether the temperature lag is superimposed, and according to the lag superimposition rule, the change trend of temperature and pressure is predicted in advance, and when the pressure starts to rise, the real temperature of waste gas in the waste gas conveying pipeline can be obtained, and temperature adjustment operation is performed according to the real temperature of waste gas, so as to avoid the decrease of purification efficiency caused by the superimposition of temperature and pressure changes.

Description

Technical Field

[0001] This invention relates to the field of waste gas purification and control technology, specifically to a waste gas purification system with intelligent temperature control and pressure monitoring. Background Technology

[0002] With the rapid development of industry, the amount of waste gas emitted from various industrial production activities is increasing day by day. The types and concentrations of pollutants contained in the waste gas are also becoming increasingly complex and diverse, causing serious pollution and damage to the atmospheric environment, and thus threatening human health and ecological balance. Therefore, waste gas purification and treatment has become an indispensable key link in industrial production. How to achieve efficient and precise waste gas purification to meet increasingly stringent environmental standards has become an important problem that urgently needs to be solved in the current industrial field.

[0003] In practical waste gas purification scenarios, especially in the waste gas treatment processes of industries such as chemical, pharmaceutical, and coating, the gas pressure and velocity in waste gas delivery pipelines often fluctuate frequently and irregularly due to the complexity and instability of production processes. This fluctuation further leads to fluctuations in waste gas temperature, and there is often a lag between waste gas temperature fluctuations and waste gas pressure fluctuations. Traditional systems can only simply monitor real-time temperature and pressure values, making it difficult to accurately determine the existence of this temperature and pressure lag, let alone the specific degree and pattern of change. Consequently, during actual operation, the system cannot perform precise temperature control based on the actual temperature conditions, easily resulting in either delayed or premature temperature control.

[0004] Therefore, the present invention provides an exhaust gas purification system with intelligent temperature control and pressure monitoring. Summary of the Invention

[0005] The purpose of this invention is to provide an exhaust gas purification system with intelligent temperature control and pressure monitoring to solve the aforementioned background problems.

[0006] The objective of this invention can be achieved through the following technical solutions: An exhaust gas purification system with intelligent temperature control and pressure monitoring includes the following modules: Air pressure fluctuation monitoring module: Set the exhaust gas purification monitoring cycle, monitor the air pressure in the exhaust gas conveying pipeline during the exhaust gas purification monitoring period, and determine the period of air pressure fluctuation; Fluctuation Cause Analysis Module: Obtain the gas delivery rate at the gas delivery pipeline inlet during each waste gas purification monitoring period, perform gas velocity fluctuation analysis, screen out gas velocity fluctuation periods, and compare them with gas pressure fluctuation periods to determine the fluctuation overlap periods. Fluctuation lag analysis module: During the fluctuation overlap period, the fluctuation analysis of the temperature change of the exhaust gas in the exhaust gas conveying pipeline is performed, and the existence of lag between the exhaust gas temperature fluctuation and the exhaust gas pressure fluctuation is evaluated to obtain the fluctuation lag period. The hysteresis superposition evaluation module constructs a temperature-pressure hysteresis fitting line if there is a hysteresis between exhaust gas temperature fluctuations and exhaust gas pressure fluctuations, and analyzes the temperature-pressure hysteresis fitting line to evaluate whether the temperature hysteresis is superimposed. Real-time acquisition module: If the temperature assessment is lagging, the unit lag superposition amount is determined, and the change analysis of the unit lag superposition amount is performed. Based on the change of the analyzed unit lag superposition amount, the real temperature acquisition time point when the current exhaust gas pressure fluctuates is determined.

[0007] As a further aspect of the present invention, the process for determining the period of air pressure fluctuation is as follows: The period of exhaust gas purification monitoring is divided into several exhaust gas purification monitoring points. The pressure change curve of the period is constructed based on the single-point air pressure monitoring value of each exhaust gas purification monitoring point. Select all pressure peaks and troughs on the pressure change curve over a period of time, and obtain the distance between adjacent pressure peaks and troughs as the pressure peak and trough change values. The average and standard deviation of all pressure peak and valley changes are calculated separately to obtain the average and standard deviation of pressure peak and valley changes. The coefficient of variation is then used to calculate the pressure fluctuation value for a period. If the pressure fluctuation value for a period is greater than or equal to the pressure fluctuation threshold for that period, it is marked as a period of pressure fluctuation.

[0008] A further aspect of this invention is as follows: The gas velocity fluctuation periods are selected and compared with the gas pressure fluctuation periods. The process for determining the overlapping fluctuation periods is as follows: The waste gas delivery volume at the waste gas purification monitoring point at the inlet of the waste gas delivery pipeline is obtained. The waste gas delivery volume corresponding to the adjacent waste gas purification monitoring point is subtracted, and the absolute value is taken. The ratio of the absolute value to the time between the adjacent waste gas purification monitoring points is calculated to obtain the unit gas velocity value. The standard deviation of all unit gas velocity values ​​is calculated to obtain the time period gas velocity analysis value. If the gas velocity analysis value for a given period is greater than the gas velocity analysis threshold for that period, it indicates that the gas delivery rate fluctuates significantly during the gas purification monitoring period, which is a period of fluctuating gas velocity. Extract all gas velocity fluctuation periods and all gas pressure fluctuation periods within the waste gas purification monitoring cycle. Compare the gas velocity fluctuation periods with the gas pressure fluctuation periods and identify the gas velocity fluctuation periods that overlap with the gas pressure fluctuation periods as the fluctuation overlap periods.

[0009] As a further aspect of the present invention, the process of evaluating whether there is a hysteresis phenomenon between exhaust gas temperature fluctuations and exhaust gas pressure fluctuations from the perspective of hysteresis quantity is as follows: Based on the exhaust gas temperature at each exhaust gas purification monitoring point during the overlapping fluctuation period, an overlapping fluctuating exhaust gas temperature curve is constructed. Temperature peak coordinates that lag behind the pressure peak and temperature trough coordinates that lag behind the pressure trough in the time dimension are extracted and denoted as temperature peak lag coordinates and temperature trough lag coordinates. The number of temperature peak lag coordinates and temperature trough lag coordinates are counted, summed, and then the ratio is calculated with the total number of temperature peak coordinates and temperature trough coordinates on the overlapping fluctuating exhaust gas temperature curve to obtain the temperature peak lag ratio.

[0010] As a further aspect of the present invention, the process of evaluating whether there is a hysteresis phenomenon between exhaust gas temperature fluctuations and exhaust gas pressure fluctuations from the perspective of hysteresis degree is as follows: The distance between the lagging coordinate point of the temperature peak and the peak point of the pressure wave on the X-axis is obtained, and the ratio is calculated with the duration of the overlapping period of the fluctuation. Then, the summation and mean are calculated to obtain the mean time interval of the temperature and pressure wave peaks. The distance between the temperature trough lag point and the pressure trough point on the X-axis is obtained, and the ratio is calculated with the duration of the overlapping period of the fluctuation. The average value is then calculated to obtain the average temperature and pressure trough interval. The mean time intervals of temperature and pressure peaks and the mean time intervals of temperature and pressure troughs are summed to obtain the lag time analysis value.

[0011] As a further aspect of the present invention, the process for determining the fluctuation lag period is as follows: The lag time analysis value is summed with the ratio of temperature wave lag quantity to obtain the temperature and pressure lag assessment value. If the temperature and pressure hysteresis assessment value is greater than the temperature and pressure hysteresis assessment threshold, it will be displayed as a temperature wave hysteresis pressure wave signal, and the analyzed fluctuation overlap period will be marked as the fluctuation hysteresis period.

[0012] As a further aspect of the present invention, the process for constructing the temperature-pressure hysteresis fitting line is as follows: Within the lag period of the fluctuation, all continuous lag time analysis values ​​in the time dimension are extracted to construct a temperature-pressure lag fitting line. On the temperature-pressure lag curve, two coordinate points are arbitrarily selected as two fitting coordinate points. These two fitting coordinate points are connected by a straight line, and the line is extended to both ends of the temperature-pressure lag curve (the starting and ending coordinates of the temperature-pressure lag curve). The temperature-pressure lag fitting equation is then constructed as follows: ,in, This is expressed as the slope of the temperature-pressure hysteresis fitting. It is represented as a constant.

[0013] As a further aspect of the present invention, the process of analyzing the temperature-pressure hysteresis fitting line and evaluating whether the temperature hysteresis is superimposed is as follows: The distance between the starting point Y coordinate of the temperature-pressure hysteresis fitting line and the starting point Y coordinate of the temperature-pressure hysteresis change curve is obtained as the fitting Y difference value. The mean of all fitted Y differences is calculated to obtain the fitted matching value. The temperature-pressure hysteresis fitting line corresponding to the smallest fitted matching value is selected as the temperature-pressure hysteresis analysis line, and the corresponding temperature-pressure hysteresis fitting equation is used as the temperature-pressure hysteresis analysis equation. ,in, As the slope of the temperature-pressure hysteresis analysis Represented as a constant; Extracting the temperature-pressure hysteresis slope from the temperature-pressure hysteresis equation If the slope of the temperature-pressure hysteresis analysis If the value is positive, it will be displayed as a hysteresis superposition signal.

[0014] As a further aspect of the present invention, the process of determining the unit hysteresis superposition amount and performing change analysis on the unit hysteresis superposition amount is as follows: Within the lag period of fluctuation, all continuous lag time analysis values ​​in the time dimension are extracted and sorted according to the order of the obtained time to obtain the lag time series. The difference between adjacent lag time analysis values ​​in the lag time series is obtained to obtain the unit lag superposition amount. The standard deviation of the lag stacking values ​​of all units is calculated to obtain the lag stacking change value.

[0015] As a further aspect of the present invention, the process for determining the actual temperature acquisition time point when the current exhaust gas pressure fluctuates is as follows: If the lag superposition change value is greater than the lag superposition change threshold, the sum of the maximum unit lag superposition amount and the minimum unit lag superposition amount is selected to calculate the average value and obtain the reference temperature lag time. If the lag superposition value is less than or equal to the lag superposition change threshold, then the unit lag superposition amount is used as the reference temperature lag time. The waste gas purification monitoring point at the time of the current waste gas pressure fluctuation is obtained, and the actual temperature acquisition time point at the time of the current waste gas pressure fluctuation is determined by combining the reference temperature lag time.

[0016] The beneficial effects of this invention are as follows: 1. This invention sets a waste gas purification monitoring cycle. During the waste gas purification monitoring period, the air pressure in the waste gas conveying pipeline is monitored to determine the air pressure fluctuation period. The air delivery rate at the inlet of the waste gas conveying pipeline is obtained for each waste gas purification monitoring period, and air velocity fluctuation analysis is performed to screen out the air velocity fluctuation period. This period is then compared with the air pressure fluctuation period to determine the fluctuation overlap period. Since temperature, air pressure, and air velocity are interrelated in the intelligent temperature control and pressure monitoring system, when the waste gas delivery rate at the inlet of the waste gas conveying pipeline fluctuates, the waste gas pressure in the waste gas conveying pipeline fluctuates, which in turn causes the waste gas temperature to fluctuate. However, because the waste gas temperature fluctuation lags behind the waste gas pressure, the temperature obtained by the temperature sensor has a lag, thus it cannot provide data support for temperature control and reduces the accuracy of temperature control.

[0017] 2. This invention performs fluctuation analysis on the temperature change of exhaust gas in the exhaust gas conveying pipeline during the overlapping period of fluctuations, and assesses whether there is a lag between the temperature fluctuation and the pressure fluctuation of exhaust gas, determining the lag period. If there is a lag between the temperature fluctuation and the pressure fluctuation, a temperature-pressure lag fitting line is constructed, and the temperature-pressure lag fitting line is analyzed to assess whether the temperature lag is superimposed. Based on the law of lag superposition, the trend of temperature and pressure change can be predicted in advance. When the pressure begins to rise, the actual temperature of the exhaust gas in the exhaust gas conveying pipeline can be obtained, and temperature adjustment operations can be performed based on the actual temperature of the exhaust gas, avoiding a decrease in purification efficiency due to the superposition of temperature and pressure changes.

[0018] 3. If the present invention assesses temperature lag, it determines the unit lag superposition amount and performs change analysis on the unit lag superposition amount. Based on the changes in the analyzed unit lag superposition amount, it determines the time point for obtaining the real air temperature when the current exhaust gas pressure fluctuates. By determining the time point for obtaining the real air temperature, it is possible to obtain the real exhaust gas temperature in the current exhaust gas conveying pipeline. This not only provides data support for subsequent adjustment of exhaust gas temperature, but also improves the accuracy of exhaust gas temperature adjustment and reduces the impact of temperature fluctuations on purification quality. Attached Figure Description

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] Figure 1 This is a functional module diagram of an exhaust gas purification system with intelligent temperature control and pressure monitoring according to the present invention. Figure 2 This is a flowchart of the steps of an exhaust gas purification system with intelligent temperature control and pressure monitoring in this invention. Figure 3 This is a flowchart illustrating the judgment process of an exhaust gas purification system with intelligent temperature control and pressure monitoring, as described in this invention. Detailed Implementation

[0021] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0022] Example 1 like Figure 1 - Figure 3 As shown, this embodiment of the invention provides a waste gas purification system with intelligent temperature control and pressure monitoring, comprising: Air pressure fluctuation monitoring module: Set the exhaust gas purification monitoring cycle, monitor the air pressure in the exhaust gas conveying pipeline during the exhaust gas purification monitoring period, and determine the period of air pressure fluctuation; In some embodiments, the exhaust gas purification monitoring cycle is equally divided into several exhaust gas purification monitoring periods, wherein the duration of each exhaust gas purification monitoring period is equal. The period of waste gas purification monitoring is divided into several waste gas purification monitoring points, and the interval between adjacent waste gas purification monitoring points is equal. The exhaust gas pressure in the exhaust gas conveying pipeline at each exhaust gas purification monitoring point is taken as the single-point air pressure monitoring value. The single-point air pressure monitoring values ​​of each exhaust gas purification monitoring point during the exhaust gas purification monitoring period are substituted into the two-dimensional coordinate system in chronological order to construct the air pressure change curve for the period, where the X-axis represents time and the Y-axis represents air pressure. It should be noted that each period of exhaust gas purification monitoring corresponds to a pressure change curve for that period. Select all pressure peaks and troughs on the pressure change curve over a period of time, and obtain the distance between adjacent pressure peaks and troughs as the pressure peak and trough change values. The average value of the peak and valley pressure changes is obtained by summing all the peak and valley pressure changes. The standard deviation of all pressure peak and valley variations is calculated to obtain the standard deviation of pressure peak and valley variations. The coefficient of variation is calculated by taking the standard deviation of the peak and valley changes and the mean of the peak and valley changes of air pressure to obtain the air pressure fluctuation value over a period of time. It is understandable that the meaning of the time period air pressure fluctuation value is: it comprehensively considers the average amplitude of air pressure fluctuation (mean of air pressure peak and valley changes) and the dispersion of the fluctuation amplitude (standard deviation) during the waste gas purification monitoring period. It is a comprehensive indicator that fully reflects the air pressure fluctuation characteristics during the waste gas purification monitoring period. Specifically, if the time period air pressure fluctuation value is large, it indicates that the air pressure fluctuation in the waste gas transmission pipeline is relatively severe during the analyzed waste gas purification monitoring period. If the time period air pressure fluctuation value is small, it indicates that the air pressure fluctuation in the waste gas transmission pipeline is relatively gentle during the analyzed waste gas purification monitoring period. If the air pressure fluctuation value during a period is greater than or equal to the air pressure fluctuation threshold during that period, it indicates that the air pressure fluctuation in the exhaust gas transmission pipeline is relatively severe during the analyzed exhaust gas purification monitoring period, and the analyzed exhaust gas purification monitoring period is marked as the air pressure fluctuation period. If the air pressure fluctuation value during a period is less than the air pressure fluctuation threshold during a period, it indicates that the air pressure fluctuation in the exhaust gas transmission pipeline is relatively gentle during the analyzed exhaust gas purification monitoring period, and the analyzed exhaust gas purification monitoring period is marked as a non-fluctuating air pressure period. It should be noted that determining the period of air pressure fluctuation is beneficial in several ways: Firstly, after determining the period of air pressure fluctuation, the system can adjust the operating parameters of the equipment for different periods. During periods of severe air pressure fluctuation, the fan power can be increased or the valve opening can be adjusted to stabilize the air pressure in the pipeline, ensure that the equipment operates under stable conditions, reduce equipment wear and failure caused by air pressure fluctuation, and extend the service life of the equipment. On the other hand, it can provide data support for real-time monitoring and adjustment of purification, avoid some exhaust gas being discharged without sufficient purification due to air pressure fluctuations, and ensure that the purification effect can meet the expected standard throughout the entire exhaust gas purification monitoring cycle, which helps to ensure the uniformity and stability of the exhaust gas purification effect.

[0023] Fluctuation Cause Analysis Module: Obtain the gas delivery rate at the gas delivery pipeline inlet during each waste gas purification monitoring period, perform gas velocity fluctuation analysis, screen out gas velocity fluctuation periods, and compare them with gas pressure fluctuation periods to determine the fluctuation overlap periods. In some embodiments, the amount of waste gas transported at the waste gas purification monitoring point at the inlet of the waste gas transport pipeline is obtained; The difference between the exhaust gas delivery volume corresponding to adjacent exhaust gas purification monitoring points is calculated, and the absolute value is then used to calculate the ratio with the duration between adjacent exhaust gas purification monitoring points to obtain the unit gas velocity value. The standard deviation of all unit gas velocity values ​​is then calculated to obtain the time period gas velocity analysis value. If the gas velocity analysis value for a given period is greater than the gas velocity analysis threshold for that period, it indicates that the gas delivery rate fluctuates significantly during the gas purification monitoring period, which is a period of fluctuating gas velocity. If the gas velocity analysis value for a given period is less than or equal to the gas velocity analysis threshold for that period, it indicates that the fluctuation in the gas delivery rate is relatively small during the gas purification monitoring period. Extract all gas velocity fluctuation periods and all gas pressure fluctuation periods within the waste gas purification monitoring cycle. Compare the gas velocity fluctuation periods with the gas pressure fluctuation periods and take the gas velocity fluctuation periods that overlap with the gas pressure fluctuation periods as the fluctuation overlap periods. The specific solution of this invention is as follows: A waste gas purification monitoring cycle is set. During the waste gas purification monitoring period, the gas pressure in the waste gas delivery pipeline is monitored to determine the gas pressure fluctuation period. The gas delivery rate at the inlet of the waste gas delivery pipeline is obtained for each waste gas purification monitoring period, and gas velocity fluctuation analysis is performed. The gas velocity fluctuation period is screened out and compared with the gas pressure fluctuation period to determine the fluctuation overlap period. Since temperature, gas pressure, and gas velocity are interrelated in the intelligent temperature control and pressure monitoring system, fluctuations in the waste gas delivery rate at the inlet of the waste gas delivery pipeline cause fluctuations in the waste gas pressure within the pipeline, resulting in fluctuations in the waste gas temperature. However, because the waste gas temperature fluctuation lags behind the waste gas pressure, the temperature obtained by the temperature sensor has a lag, thus failing to provide data support for temperature control and reducing the accuracy of temperature control.

[0024] Example 2 like Figure 1 - Figure 3 As shown, this embodiment of the invention provides a waste gas purification system with intelligent temperature control and pressure monitoring, and further includes: Fluctuation lag analysis module: During the fluctuation overlap period, the fluctuation analysis of the temperature change of the exhaust gas in the exhaust gas conveying pipeline is performed, and the existence of lag between the exhaust gas temperature fluctuation and the exhaust gas pressure fluctuation is evaluated to determine the fluctuation lag period. In some embodiments, during the overlapping period of fluctuations, the exhaust gas temperature at each exhaust gas purification monitoring point is obtained using a temperature sensor, and the obtained time sequence is substituted into a two-dimensional coordinate system to construct an overlapping exhaust gas temperature curve, where the X-axis represents time and the Y-axis represents exhaust gas temperature. Extract the coordinates of the temperature peaks and troughs on the temperature curves of the fluctuating and overlapping exhaust gases, respectively. For example, temperature peak coordinates that lag behind the pressure peak and temperature trough coordinates that lag behind the pressure trough in the time dimension are extracted and denoted as temperature peak lag coordinates and temperature trough lag coordinates, respectively. The number of temperature peak lag coordinates and the number of temperature trough lag coordinates are counted, summed, and then the ratio is calculated with the total number of temperature peak coordinates and temperature trough coordinates on the fluctuating and overlapping exhaust gas temperature curve to obtain the temperature wave lag ratio. It should be noted that the temperature peak coordinate point that lags behind the pressure peak point in the time dimension refers to: for example, if the first temperature peak coordinate point on the fluctuating and overlapping exhaust gas temperature curve is later than the first pressure peak point on the pressure change curve in the time dimension, then it is the temperature peak lag coordinate point, and the number of pressure peak points and temperature peak coordinate points is the same. In the time dimension, the temperature trough coordinate point that lags behind the pressure trough point refers to: for example, the first temperature trough coordinate point on the fluctuating and overlapping exhaust gas temperature curve is later in time than the first pressure trough point on the pressure change curve of the same period. This is the temperature trough lag coordinate point, and the number of pressure trough points and temperature trough coordinate points is the same. The distance between the lagging coordinate point of the temperature peak and the peak point of the pressure wave on the X-axis is obtained, and the ratio is calculated with the duration of the overlapping period of the fluctuation. Then, the summation and mean are calculated to obtain the mean time interval of the temperature and pressure wave peaks. The distance between the temperature trough lag point and the pressure trough point on the X-axis is obtained, and the ratio is calculated with the duration of the overlapping period of the fluctuation. The average value is then calculated to obtain the average temperature and pressure trough interval. The average time interval between temperature and pressure peaks and the average time interval between temperature and pressure troughs are summed to obtain the lag time analysis value. The lag time analysis value is then summed with the ratio of temperature wave lag quantity to obtain the temperature and pressure lag assessment value. It is understandable that the temperature and pressure lag assessment value represents not only the prevalence of lag phenomena (temperature wave lag ratio) but also the average degree of lag time (period lag analysis value). Thus, it reflects the lag between exhaust gas temperature fluctuations and exhaust gas pressure fluctuations. Specifically, on the one hand, the temperature wave lag ratio reflects the proportion of temperature peaks lagging behind pressure peaks and temperature troughs lagging behind pressure troughs in the entire temperature fluctuation during the overlapping period of fluctuations. On the other hand, the lag time analysis value reflects the degree of time lag between temperature fluctuations and pressure fluctuations during the entire overlapping period of fluctuations. If the temperature and pressure lag assessment value is greater than the temperature and pressure lag assessment threshold, it indicates that the temperature fluctuation lag phenomenon occurs more frequently in the overall temperature fluctuation process, and the temperature fluctuation lags behind the pressure fluctuation in time. This is displayed as a temperature wave lags behind the pressure wave signal, and the fluctuation overlap period analyzed is marked as the fluctuation lag period. If the temperature and pressure hysteresis evaluation value is less than or equal to the temperature and pressure hysteresis evaluation threshold, it indicates that the frequency of temperature fluctuation hysteresis phenomenon is low in the overall temperature fluctuation process, and the temperature fluctuation is relatively lagging behind the pressure fluctuation in time, which is displayed as a temperature wave non-hysteresis pressure wave signal. The hysteresis superposition evaluation module constructs a temperature-pressure hysteresis fitting line if there is a hysteresis between exhaust gas temperature fluctuations and exhaust gas pressure fluctuations, and analyzes the temperature-pressure hysteresis fitting line to evaluate whether the temperature hysteresis is superimposed. In some embodiments, during the fluctuation lag period, all lag time analysis values ​​that are continuous in the time dimension are extracted and substituted into the two-dimensional coordinate system in chronological order to construct the temperature and pressure lag fitting line. For example, in the temperature-pressure hysteresis curve, arbitrarily select two coordinate points as two fitting coordinate points, connect the two fitting coordinate points with a straight line, and extend the line to both ends of the temperature-pressure hysteresis curve (the starting coordinates and the ending coordinates of the temperature-pressure hysteresis curve), constructing a temperature-pressure hysteresis fitting line. Then, the temperature-pressure hysteresis fitting equation is: ,in, This is expressed as the slope of the temperature-pressure hysteresis fitting. Represented as a constant; It should be noted that connecting the two fitted coordinate points with a straight line and extending it to both ends of the temperature-pressure hysteresis curve, that is, using the X-axis coordinates of both ends of the temperature-pressure hysteresis curve (the starting coordinates and the ending coordinates of the temperature-pressure hysteresis curve) as the reference, aligning the starting X-coordinate of the temperature-pressure hysteresis fitting line with the starting X-coordinate of the temperature-pressure hysteresis curve, and aligning the starting Y-coordinate of the temperature-pressure hysteresis fitting line with the starting Y-coordinate of the temperature-pressure hysteresis curve; For example, the distance between the starting point Y coordinate on the temperature-pressure hysteresis fitting line and the starting point Y coordinate on the temperature-pressure hysteresis change curve is obtained as the fitting Y difference value; The mean of all fitted Y differences is calculated to obtain the fitted matching value. The temperature-pressure hysteresis fitting line corresponding to the smallest fitted matching value is selected as the temperature-pressure hysteresis analysis line, and the corresponding temperature-pressure hysteresis fitting equation is used as the temperature-pressure hysteresis analysis equation. ,in, As the slope of the temperature-pressure hysteresis analysis Represented as a constant; Extracting the temperature-pressure hysteresis slope from the temperature-pressure hysteresis equation If the slope of the temperature-pressure hysteresis analysis If the value is positive, it indicates that the temperature and pressure lag curve is approximately monotonically increasing, meaning that the temperature and pressure changes are superimposed in the time dimension within the analyzed temperature and pressure lag period, and are displayed as a lag superposition signal. If the slope of the temperature and pressure hysteresis analysis If the value is 0, it means that the temperature and pressure hysteresis curve is approximately a straight line parallel to the X-axis, that is, the temperature and pressure changes are in a stable state in the time dimension during the analyzed temperature and pressure hysteresis period, which is displayed as a hysteresis stable signal. If the slope of the temperature and pressure hysteresis analysis If the value is negative, it indicates that the temperature and pressure lag curve is approximately monotonically decreasing, meaning that the temperature and pressure changes lag and decay in the time dimension during the analyzed temperature and pressure lag period, which is displayed as a lag decay signal. The specific solution in this embodiment is as follows: During the overlapping period of fluctuations, the temperature change of the exhaust gas in the exhaust gas conveying pipeline is analyzed, and it is assessed whether there is a lag between the temperature fluctuation and the pressure fluctuation. The lag period is determined. If there is a lag between the temperature fluctuation and the pressure fluctuation, a temperature-pressure lag fitting line is constructed, and the temperature-pressure lag fitting line is analyzed to assess whether the temperature lag is superimposed. Based on the law of lag superposition, the trend of temperature and pressure changes is predicted in advance. When the pressure begins to rise, the actual temperature of the exhaust gas in the exhaust gas conveying pipeline can be obtained, and temperature adjustment operations can be performed based on the actual temperature of the exhaust gas to avoid a decrease in purification efficiency due to the superposition of temperature and pressure changes.

[0025] Example 3 like Figure 1 - Figure 3 As shown, this embodiment of the invention provides a waste gas purification system with intelligent temperature control and pressure monitoring, and further includes: Real-time acquisition module: If the temperature assessment is lagging, the unit lag superposition amount is determined, and the change analysis of the unit lag superposition amount is performed. Based on the change of the analyzed unit lag superposition amount, the real temperature acquisition time point when the current exhaust gas pressure fluctuates is determined. In some embodiments, during the fluctuation lag period, all lag time analysis values ​​that are continuous in the time dimension are extracted and sorted according to the order of the acquired time to obtain the lag time series. The difference between adjacent lag time analysis values ​​within the lag time series is used to obtain the unit lag superposition amount; The standard deviation of the hysteresis stacking of all units is calculated to obtain the hysteresis stacking change value; If the value of the lag superposition change is greater than the threshold value of the lag superposition change, it indicates that the time degree of each temperature lag superposition is unstable during the fluctuation lag period. Then, the maximum unit lag superposition amount and the minimum unit lag superposition amount are selected to calculate the average value of the sum to obtain the reference temperature lag time. If the lag superposition value is less than or equal to the lag superposition change threshold, it indicates that the time degree of temperature lag superposition is stable during the fluctuation lag period. In this case, the unit lag superposition amount is used as the reference temperature lag time. The waste gas purification monitoring point at the time of the current waste gas pressure fluctuation is obtained, and the actual temperature acquisition time point at the time of the current waste gas pressure fluctuation is determined by combining the reference temperature lag time. The specific solution in this embodiment is as follows: If the temperature lag is assessed, the unit lag superposition amount is determined, and the change of the unit lag superposition amount is analyzed. Based on the change of the analyzed unit lag superposition amount, the time point for obtaining the real air temperature when the current exhaust gas pressure fluctuates is determined. By determining the time point for obtaining the real air temperature, the real exhaust gas temperature in the current exhaust gas conveying pipeline can be obtained. This not only provides data support for subsequent adjustment of exhaust gas temperature, but also improves the accuracy of exhaust gas temperature adjustment and reduces the impact of temperature fluctuations on purification quality.

[0026] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A waste gas purification system with intelligent temperature control and pressure monitoring, characterized in that: Air pressure fluctuation monitoring module: Set the exhaust gas purification monitoring cycle, monitor the air pressure in the exhaust gas conveying pipeline during the exhaust gas purification monitoring period, and determine the period of air pressure fluctuation; Fluctuation Cause Analysis Module: Obtain the gas delivery rate at the gas delivery pipeline inlet during each waste gas purification monitoring period, perform gas velocity fluctuation analysis, screen out gas velocity fluctuation periods, and compare them with gas pressure fluctuation periods to determine the fluctuation overlap periods. Fluctuation lag analysis module: During the fluctuation overlap period, the fluctuation analysis of the temperature change of the exhaust gas in the exhaust gas conveying pipeline is performed, and the existence of lag between the exhaust gas temperature fluctuation and the exhaust gas pressure fluctuation is evaluated to obtain the fluctuation lag period. The hysteresis superposition evaluation module constructs a temperature-pressure hysteresis fitting line if there is a hysteresis between exhaust gas temperature fluctuations and exhaust gas pressure fluctuations, and analyzes the temperature-pressure hysteresis fitting line to evaluate whether the temperature hysteresis is superimposed. Real-time acquisition module: If the temperature assessment is lagging, the unit lag superposition amount is determined, and the change analysis of the unit lag superposition amount is performed. Based on the change of the analyzed unit lag superposition amount, the real temperature acquisition time point when the current exhaust gas pressure fluctuates is determined.

2. The exhaust gas purification system with intelligent temperature control and pressure monitoring according to claim 1, characterized in that: The process for determining the period of air pressure fluctuation is as follows: The period of exhaust gas purification monitoring is divided into several exhaust gas purification monitoring points. The pressure change curve of the period is constructed based on the single-point air pressure monitoring value of each exhaust gas purification monitoring point. Select all pressure peaks and troughs on the pressure change curve over a period of time, and obtain the distance between adjacent pressure peaks and troughs as the pressure peak and trough change values. The average and standard deviation of all pressure peak and valley changes are calculated separately to obtain the average and standard deviation of pressure peak and valley changes. The coefficient of variation is then used to calculate the pressure fluctuation value for a period. If the pressure fluctuation value for a period is greater than or equal to the pressure fluctuation threshold for that period, it is marked as a period of pressure fluctuation.

3. The exhaust gas purification system with intelligent temperature control and pressure monitoring according to claim 1, characterized in that: Periods of air velocity fluctuation were identified and compared with periods of air pressure fluctuation. The process for determining the overlapping periods of fluctuation is as follows: The waste gas delivery volume at the waste gas purification monitoring point at the inlet of the waste gas delivery pipeline is obtained. The waste gas delivery volume corresponding to the adjacent waste gas purification monitoring point is subtracted, and the absolute value is taken. The ratio of the absolute value to the time between the adjacent waste gas purification monitoring points is calculated to obtain the unit gas velocity value. The standard deviation of all unit gas velocity values ​​is calculated to obtain the time period gas velocity analysis value. If the gas velocity analysis value for a given period is greater than the gas velocity analysis threshold for that period, it indicates that the gas delivery rate fluctuates significantly during the gas purification monitoring period, which is a period of fluctuating gas velocity. Extract all gas velocity fluctuation periods and all gas pressure fluctuation periods within the waste gas purification monitoring cycle. Compare the gas velocity fluctuation periods with the gas pressure fluctuation periods and identify the gas velocity fluctuation periods that overlap with the gas pressure fluctuation periods as the fluctuation overlap periods.

4. The exhaust gas purification system with intelligent temperature control and pressure monitoring according to claim 1, characterized in that: The process of assessing whether there is a lag between exhaust gas temperature fluctuations and exhaust gas pressure fluctuations from the perspective of lag quantity is as follows: Based on the exhaust gas temperature at each exhaust gas purification monitoring point during the overlapping fluctuation period, an overlapping fluctuating exhaust gas temperature curve is constructed. Temperature peak coordinates that lag behind the pressure peak and temperature trough coordinates that lag behind the pressure trough in the time dimension are extracted and denoted as temperature peak lag coordinates and temperature trough lag coordinates. The number of temperature peak lag coordinates and temperature trough lag coordinates are counted, summed, and then the ratio is calculated with the total number of temperature peak coordinates and temperature trough coordinates on the overlapping fluctuating exhaust gas temperature curve to obtain the temperature peak lag ratio.

5. The exhaust gas purification system with intelligent temperature control and pressure monitoring according to claim 4, characterized in that: The process of assessing whether there is a lag between exhaust gas temperature fluctuations and exhaust gas pressure fluctuations from the perspective of lag degree is as follows: The distance between the lagging coordinate point of the temperature peak and the peak point of the pressure wave on the X-axis is obtained, and the ratio is calculated with the duration of the overlapping period of the fluctuation. Then, the summation and mean are calculated to obtain the mean time interval of the temperature and pressure wave peaks. The distance between the temperature trough lag point and the pressure trough point on the X-axis is obtained, and the ratio is calculated with the duration of the overlapping period of the fluctuation. The average value is then calculated to obtain the average temperature and pressure trough interval. The mean time intervals of temperature and pressure peaks and the mean time intervals of temperature and pressure troughs are summed to obtain the lag time analysis value.

6. The exhaust gas purification system with intelligent temperature control and pressure monitoring according to claim 5, characterized in that: The process for determining the fluctuation lag period is as follows: The lag time analysis value is summed with the ratio of temperature wave lag quantity to obtain the temperature and pressure lag assessment value. If the temperature and pressure hysteresis assessment value is greater than the temperature and pressure hysteresis assessment threshold, it will be displayed as a temperature wave hysteresis pressure wave signal, and the analyzed fluctuation overlap period will be marked as the fluctuation hysteresis period.

7. The exhaust gas purification system with intelligent temperature control and pressure monitoring according to claim 1, characterized in that: The process of constructing the temperature-pressure hysteresis fitting line is as follows: Within the lag period of the fluctuation, all continuous lag time analysis values ​​in the time dimension are extracted to construct a temperature-pressure lag fitting line. On the temperature-pressure lag curve, two coordinate points are arbitrarily selected as two fitting coordinate points. These two fitting coordinate points are connected by a straight line, and the line is extended to both ends of the temperature-pressure lag curve (the starting and ending coordinates of the temperature-pressure lag curve). The temperature-pressure lag fitting equation is then constructed as follows: ,in, This is expressed as the slope of the temperature-pressure hysteresis fitting. It is represented as a constant.

8. The exhaust gas purification system with intelligent temperature control and pressure monitoring according to claim 7, characterized in that: The process of analyzing the temperature-pressure hysteresis fitting line and evaluating whether the temperature hysteresis is superimposed is as follows: The distance between the starting point Y coordinate of the temperature-pressure hysteresis fitting line and the starting point Y coordinate of the temperature-pressure hysteresis change curve is obtained as the fitting Y difference value. The mean of all fitted Y differences is calculated to obtain the fitted matching value. The temperature-pressure hysteresis fitting line corresponding to the smallest fitted matching value is selected as the temperature-pressure hysteresis analysis line, and the corresponding temperature-pressure hysteresis fitting equation is used as the temperature-pressure hysteresis analysis equation. ,in, As the slope of the temperature-pressure hysteresis analysis Represented as a constant; Extracting the temperature-pressure hysteresis slope from the temperature-pressure hysteresis equation If the slope of the temperature-pressure hysteresis analysis If the value is positive, it will be displayed as a hysteresis superposition signal.

9. The exhaust gas purification system with intelligent temperature control and pressure monitoring according to claim 1, characterized in that: The process of determining the unit hysteresis stacking amount and performing change analysis on the unit hysteresis stacking amount is as follows: Within the lag period of fluctuation, all continuous lag time analysis values ​​in the time dimension are extracted and sorted according to the order of the obtained time to obtain the lag time series. The difference between adjacent lag time analysis values ​​in the lag time series is obtained to obtain the unit lag superposition amount. The standard deviation of the lag stacking values ​​of all units is calculated to obtain the lag stacking change value.

10. A waste gas purification system with intelligent temperature control and pressure monitoring according to claim 9, characterized in that: The process for determining the actual temperature acquisition time point when the current exhaust gas pressure fluctuates is as follows: If the lag superposition change value is greater than the lag superposition change threshold, the sum of the maximum unit lag superposition amount and the minimum unit lag superposition amount is selected to calculate the average value and obtain the reference temperature lag time. If the lag superposition value is less than or equal to the lag superposition change threshold, then the unit lag superposition amount is used as the reference temperature lag time. The waste gas purification monitoring point at the time of the current waste gas pressure fluctuation is obtained, and the actual temperature acquisition time point at the time of the current waste gas pressure fluctuation is determined by combining the reference temperature lag time.

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