Urea concentration regulation and control system and method in denitration process

Abstract

The invention discloses a urea concentration regulation and control system and method in a denitration process, and the system comprises an obtaining module which is used for setting the monitoring time interval of each boiler injection region, and obtaining the real-time operation parameters of the corresponding boiler injection region according to the monitoring time interval; the generation module is used for generating a regulation and control instruction of the urea solution in the static mixer according to the real-time operation parameters; the judgment module is used for presetting a urea requirement index, obtaining the actual urea solution concentration after the regulation and control instruction, and judging whether the actual urea solution concentration meets the urea requirement index or not; the regulation and control module is used for generating a correction instruction of regulation and control parameters in the regulation and control instruction according to the judgment result; the accurate regulation and evaluation of the urea concentration are realized, so that the regulated urea solution concentration meets the emission standard of each boiler injection area, the denitration cost is reduced, the denitration efficiency is improved, and the safe and economical operation of the boiler is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of flue gas denitrification, and in particular to a urea concentration control system and method in a denitrification process. Background Art

[0002] The regulation of urea concentration in the denitrification process mainly involves adjusting the concentration, metering and conveying the urea solution from the urea solution circulation pump and the solution storage tank through the reducing agent injection pump and the mixer. The urea solution enters the distribution system after concentration adjustment and metering, and is distributed to the spray gun area of ​​each boiler injection area by the distribution system to meet the nitrogen oxide emission standards of the corresponding boiler injection area. In order to avoid excessive emissions, the urea concentration needs to be regulated and accurately evaluated. Therefore, in order to improve the accuracy of urea concentration regulation and evaluation and ensure safe and economical operation of the boiler, a urea concentration control system and method for a denitrification process is urgently needed. Summary of the invention

[0003] To solve the above technical problems, the present application provides a urea concentration control system and method in a denitrification process, which obtains the real-time operating parameters of each boiler injection area according to the monitoring time interval, generates a control instruction of the urea solution according to the real-time operating parameters, obtains the actual urea solution concentration after control, and determines whether the urea requirement instruction is met. If not, a correction instruction of the control instruction is generated to achieve precise control and evaluation of the urea concentration, so that the urea solution concentration after control meets the emission standards of each boiler injection area, reduces the denitrification cost and improves the denitrification efficiency, and ensures the safe and economical operation of the boiler.

[0004] In some embodiments of the present application, a urea concentration control system in a denitrification process is provided, comprising:

[0005] An acquisition module, used to set a monitoring time interval for each boiler injection area, and acquire real-time operating parameters of the corresponding boiler injection area according to the monitoring time interval;

[0006] A generation module, used for generating control instructions for the urea solution in the static mixer according to real-time operating parameters;

[0007] A judgment module is used to pre-set the urea requirement index, obtain the actual urea solution concentration after the control instruction, and judge whether the actual urea solution concentration meets the urea requirement index;

[0008] The control module is used to generate a correction instruction for the control parameters in the control instruction according to the judgment result.

[0009] In some embodiments of the present application, setting a monitoring time interval for each boiler injection zone includes:

[0010] Obtaining historical operating parameters of each boiler injection area in the previous adjacent preset time period, wherein the historical operating parameters include boiler load, nitrogen oxide content, and fuel quantity;

[0011] Constructing a first change curve, a second change curve and a third change curve in the previous adjacent preset time period respectively according to the boiler load, the nitrogen oxide content and the fuel amount;

[0012] determining a first change degree of boiler load according to the first change curve, determining a second change degree of nitrogen oxide content according to the second change curve, and determining a third change degree of fuel amount according to the third change curve;

[0013] A comprehensive degree of change is determined according to the first degree of change, the second degree of change and the third degree of change, and a monitoring time interval corresponding to the boiler injection area is set according to the comprehensive degree of change.

[0014] In some embodiments of the present application, generating a control instruction of a urea solution in a static mixer according to real-time operating parameters includes:

[0015] Acquire the real-time operating parameters of each boiler injection area according to the monitoring time interval, input the real-time operating parameters into the urea concentration prediction model trained in advance for each boiler injection area, and obtain multiple predicted urea concentrations;

[0016] Comprehensively analyze multiple predicted urea concentrations to determine the characteristic urea concentration;

[0017] A control instruction is generated according to the characteristic urea concentration, and the control parameters in the control instruction include the real-time opening of the dilution water pipeline proportional valve and the urea solution water pipeline proportional valve.

[0018] In some embodiments of the present application, the urea requirement index is pre-set, including:

[0019] The urea requirement index includes a urea concentration requirement index, a urea cost requirement index and a urea concentration stability requirement index;

[0020] Generate a standard urea concentration of the corresponding boiler injection area according to the real-time operating parameters of each boiler injection area, and subtract each standard urea concentration from the remaining standard urea concentrations to obtain multiple standard urea concentration difference values ​​of each standard urea concentration;

[0021] If the standard urea concentration difference of the current standard urea concentration is greater than the preset difference threshold and the number of standard urea concentration difference values ​​greater than the preset difference threshold is greater than the preset number threshold, the current standard urea concentration is eliminated, and a comprehensive standard urea concentration interval is constructed according to the standard urea concentration that is not eliminated, and the indicator evaluation coefficient of the urea concentration requirement indicator is set according to the comprehensive standard urea concentration interval;

[0022] Predicting the target urea flow rate of all boiler injection areas according to each standard urea concentration in the comprehensive standard urea concentration range, inputting each standard urea concentration and the corresponding target urea flow rate of all boiler injection areas into a preset urea cost prediction model to obtain the predicted urea cost corresponding to the current standard urea concentration, constructing a standard urea cost range according to the predicted urea cost less than a preset urea cost threshold, and setting an indicator evaluation coefficient of the urea cost requirement indicator according to the standard urea cost range;

[0023] Obtain the historical configuration log of each standard urea concentration in the comprehensive standard urea concentration range, generate multiple historical stabilities of the corresponding standard urea concentration according to the historical configuration duration in the historical configuration log and the historical change characteristics of the corresponding standard urea concentration, generate a stability evaluation value of the historical stability of the current standard urea concentration according to the historical emission log corresponding to the historical configuration log, eliminate the historical stability whose stability evaluation value is less than a preset stability evaluation value threshold, and generate the standard stability range of the current standard urea concentration with the remaining historical stabilities;

[0024] The index evaluation coefficient of the urea concentration stability requirement index is set according to the standard stability interval of each standard urea concentration in the comprehensive standard urea concentration interval.

[0025] In some embodiments of the present application, an index evaluation coefficient of the urea concentration requirement index corresponding to the standard urea concentration is set according to the standard urea concentration difference of the standard urea concentration in the comprehensive standard urea concentration interval;

[0026] The calculation formula of the index evaluation coefficient of the urea concentration requirement index is:

[0027]

[0028] Wherein, y1f is the index evaluation coefficient of the f-th standard urea concentration in the urea concentration requirement index, z1 is the first index evaluation conversion coefficient, n,f is the number of standard urea concentration difference values ​​of the f-th standard urea concentration that are greater than the preset difference threshold, m is the total number of standard urea concentrations, m-1 is the total number of standard urea concentration differences, △Ai,f is the i-th standard urea concentration difference value of the f-th annotated urea concentration;

[0029] The index evaluation coefficients of the standard urea concentrations in the comprehensive standard urea concentration range in the urea concentration requirement index are sorted according to size to obtain the index evaluation coefficient sequence Y1, Y1(y11, y21, ..., y1m) of the urea concentration requirement index, wherein y1f is the index evaluation coefficient of the f-th standard urea concentration, and y11<y21<...<y1m;

[0030] Divide the standard urea cost interval into multiple standard urea cost sub-intervals, sort each standard urea cost sub-interval according to size, and obtain a standard urea cost sub-interval sequence B, B(b1, b2, ..., bj), where bv is the vth standard urea cost sub-interval, and b1>b2>...>bj;

[0031] Each standard urea cost sub-interval in the standard urea cost sequence is configured with an index evaluation coefficient of a corresponding urea cost requirement index, and an index evaluation coefficient sequence Y2, Y2(y21, y22, ..., y2j) of the urea cost requirement index is obtained, wherein y2v is the index evaluation coefficient of the vth standard urea cost sub-interval, and y21<y22<...<y2j;

[0032] Divide the standard stability interval of each standard urea concentration in the comprehensive standard urea concentration interval into a plurality of standard stability subintervals, sort the standard stability subintervals of each standard stability interval according to size, and obtain a standard stability subinterval sequence C, C (c1, c2, ..., cg) corresponding to the standard urea concentration, wherein cx is the xth standard stability subinterval, and c1<c2<...<cg;

[0033] Each standard stability sub-interval in the standard stability sequence is configured with a corresponding indicator evaluation coefficient of the urea concentration stability requirement indicator, and an indicator evaluation coefficient sequence Y3, Y3 (y31, y32, ..., y3g) of the urea concentration requirement indicator is obtained, wherein y3x is the indicator evaluation coefficient of the x-th standard stability sub-interval, and y31<y32<...<y3g.

[0034] In some embodiments of the present application, judging whether the preset urea requirement index is met according to the actual urea solution concentration includes:

[0035] Perform similarity analysis on the actual urea solution concentration and the standard urea concentration in the comprehensive standard urea concentration range, and set the index evaluation coefficient of the marked urea concentration with the greatest similarity to the actual urea solution concentration in the index evaluation coefficient sequence Y1 of the urea concentration requirement index as the actual index evaluation coefficient of the current actual urea solution concentration;

[0036] Predicting the actual urea flow rate of all boiler injection areas according to the actual urea solution concentration, inputting the actual urea solution concentration and the actual urea flow rate of all boiler injection areas into a preset urea cost prediction model to obtain a predicted urea cost of the actual urea solution concentration;

[0037] The predicted urea cost of the actual urea solution concentration is compared with the standard urea cost sub-interval in the standard urea cost sequence, and the index evaluation coefficient of the standard urea cost sub-interval in which the predicted urea cost of the actual urea solution concentration is located in the index evaluation coefficient sequence Y2 of the urea cost requirement index is set as the actual index evaluation coefficient of the predicted urea cost of the current actual urea solution concentration;

[0038] Acquire multiple actual urea solution concentrations within the control time of the control instruction, construct an actual urea solution concentration change curve, and generate an actual stability of the current actual urea solution concentration according to the actual change characteristics of the actual urea solution concentration in the actual urea solution concentration change curve;

[0039] Perform similarity analysis on the actual stability and the standard urea concentration in the comprehensive standard urea concentration interval, compare the standard stability sub-interval sequence of the standard stability interval of the standard urea concentration with the greatest similarity between the actual stability and the actual urea solution concentration, and set the index evaluation coefficient of the standard stability sub-interval where the actual stability is located in the index evaluation coefficient sequence Y3 of the urea concentration stability index as the actual index evaluation coefficient of the actual stability of the current actual urea solution concentration;

[0040] Generate a predicted denitration efficiency of each boiler injection area according to the actual urea solution concentration and the predicted urea flow rate allocated to each boiler injection area, compare the predicted denitration efficiency of each boiler injection area with the corresponding preset denitration efficiency threshold, and generate a compensation coefficient according to the comparison results of all boiler injection areas;

[0041] A comprehensive evaluation coefficient of a preset urea requirement index is generated according to actual index evaluation coefficients of the urea concentration requirement index, the urea cost requirement index, the urea concentration stability requirement index, and a compensation coefficient.

[0042] In some embodiments of the present application, the calculation formula of the comprehensive evaluation coefficient is:

[0043] Y=r×(y1f×d1+y2v×d2+y3x×d3);

[0044] Wherein, Y is the comprehensive evaluation coefficient, d1 is the weight coefficient of the urea concentration requirement index, d2 is the weight coefficient of the urea cost requirement index, d3 is the weight coefficient of the urea concentration stability requirement index, r is the compensation coefficient, and 0.75<r<1.25;

[0045] Pre-set comprehensive evaluation coefficient threshold;

[0046] When the comprehensive evaluation coefficient is less than the comprehensive evaluation coefficient threshold, the current actual urea concentration does not meet the preset urea requirement index, and a correction instruction is generated for the control parameter in the control instruction;

[0047] When the comprehensive evaluation coefficient is greater than the comprehensive evaluation coefficient threshold, the current actual urea concentration meets the preset urea requirement index, and no correction instruction is generated for the control parameters in the control instruction.

[0048] In some embodiments of the present application, generating a correction instruction of the control instruction according to the judgment result includes:

[0049] When the judgment result is that the current actual urea concentration does not meet the preset urea requirement index, the actual index evaluation coefficients of the urea concentration requirement index, the urea cost requirement index and the urea concentration stability requirement index are respectively compared with the maximum index evaluation coefficient in the corresponding index evaluation coefficient sequence, and the index deviation level is determined according to the comparison result;

[0050] A correction instruction of the control instruction is generated according to the index deviation level, and the correction instruction includes an opening adjustment range of one or more of the dilution water pipeline proportional valve and the urea solution water pipeline proportional valve.

[0051] In some embodiments of the present application, determining the indicator deviation level according to the comparison result includes:

[0052] The calculation formula of the indicator deviation level is:

[0053]

[0054] Among them, P is the indicator deviation level, t1 is the first indicator deviation level conversion coefficient, y1m is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y1 of the urea concentration requirement indicator, y2j is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y2 of the urea cost requirement indicator, y3g is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y3 of the urea concentration stability requirement indicator, t2 is the second indicator deviation level conversion coefficient, t3 is the third indicator deviation level conversion coefficient, is the ceiling rounding function;

[0055] The opening adjustment range T is: T=P×1%.

[0056] In some embodiments of the present application, a method for controlling urea concentration in a denitrification process is also included:

[0057] Set a monitoring time interval for each boiler injection area, and obtain real-time operating parameters of the corresponding boiler injection area according to the monitoring time interval;

[0058] Generate control instructions for urea solution in the static mixer according to real-time operating parameters;

[0059] Preset the urea requirement index, obtain the actual urea solution concentration after the control instruction, and judge whether the actual urea solution concentration meets the urea requirement index;

[0060] Generate a correction instruction for the control parameter in the control instruction according to the judgment result.

[0061] Compared with the prior art, the urea concentration control system and method in a denitration process of the present application has the following beneficial effects:

[0062] By acquiring the real-time operating parameters of each boiler injection area according to the monitoring time interval, the control instructions of the urea solution are generated according to the real-time operating parameters, the actual urea solution concentration after control is obtained, and it is judged whether the urea requirement instruction is met. If not, a correction instruction of the control instruction is generated to achieve precise control and evaluation of the urea concentration, so that the urea solution concentration after control meets the emission standards of each boiler injection area, reduces the denitrification cost and improves the denitrification efficiency, and ensures the safe and economical operation of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a schematic diagram of a urea concentration control system in a denitrification process in a preferred embodiment of the present application;

[0064] Figure 2 It is a flow chart of a method for controlling urea concentration in a denitrification process in a preferred embodiment of the present application. DETAILED DESCRIPTION

[0065] The specific implementation methods of the present application are further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but are not intended to limit the scope of the present application.

[0066] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0067] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0068] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0069] like Figure 1 As shown, a urea concentration control system in a denitrification process according to a preferred embodiment of the present application includes:

[0070] An acquisition module, used to set a monitoring time interval for each boiler injection area, and acquire real-time operating parameters of the corresponding boiler injection area according to the monitoring time interval;

[0071] A generation module, used for generating control instructions for the urea solution in the static mixer according to real-time operating parameters;

[0072] A judgment module is used to pre-set the urea requirement index, obtain the actual urea solution concentration after the control instruction, and judge whether the actual urea solution concentration meets the urea requirement index;

[0073] The control module is used to generate a correction instruction for the control parameters in the control instruction according to the judgment result.

[0074] In some embodiments of the present application, setting a monitoring time interval for each boiler injection zone includes:

[0075] Obtaining historical operating parameters of each boiler injection area in the previous adjacent preset time period, wherein the historical operating parameters include boiler load, nitrogen oxide content, and fuel quantity;

[0076] Constructing a first change curve, a second change curve and a third change curve in the previous adjacent preset time period respectively according to the boiler load, the nitrogen oxide content and the fuel amount;

[0077] determining a first change degree of boiler load according to the first change curve, determining a second change degree of nitrogen oxide content according to the second change curve, and determining a third change degree of fuel amount according to the third change curve;

[0078] A comprehensive degree of change is determined according to the first degree of change, the second degree of change and the third degree of change, and a monitoring time interval corresponding to the boiler injection area is set according to the comprehensive degree of change.

[0079] In this embodiment, when the comprehensive change degree is smaller, the monitoring time interval is larger, and when the comprehensive change degree is larger, the monitoring time interval is smaller.

[0080] In this embodiment, the first change degree, the second change degree and the third change degree refer to the change rates of the boiler load, the nitrogen oxide content and the fuel amount in the previous adjacent preset time period, respectively. The comprehensive change rate is determined according to the change rate and the monitoring time interval is set to ensure the monitoring accuracy of the boiler load, the nitrogen oxide content and the fuel amount, and improve the accuracy of the subsequent urea solution concentration setting.

[0081] In some embodiments of the present application, generating a control instruction of a urea solution in a static mixer according to real-time operating parameters includes:

[0082] Acquire the real-time operating parameters of each boiler injection area according to the monitoring time interval, input the real-time operating parameters into the urea concentration prediction model trained in advance for each boiler injection area, and obtain multiple predicted urea concentrations;

[0083] Comprehensively analyze multiple predicted urea concentrations to determine the characteristic urea concentration;

[0084] A control instruction is generated according to the characteristic urea concentration, and the control parameters in the control instruction include the real-time opening of the dilution water pipeline proportional valve and the urea solution water pipeline proportional valve.

[0085] In this embodiment, the static mixer is connected to the dilution water pipeline and the urea solution water pipeline, and the real-time opening of the proportional valve of the water release pipeline and the proportional valve of the urea solution water pipeline are regulated to achieve precise control of the concentration of the urea solution.

[0086] In some embodiments of the present application, the urea requirement index is pre-set, including:

[0087] The urea requirement index includes a urea concentration requirement index, a urea cost requirement index and a urea concentration stability requirement index;

[0088] Generate a standard urea concentration of the corresponding boiler injection area according to the real-time operating parameters of each boiler injection area, and subtract each standard urea concentration from the remaining standard urea concentrations to obtain multiple standard urea concentration difference values ​​of each standard urea concentration;

[0089] If the standard urea concentration difference of the current standard urea concentration is greater than the preset difference threshold and the number of standard urea concentration difference values ​​greater than the preset difference threshold is greater than the preset number threshold, the current standard urea concentration is eliminated, and a comprehensive standard urea concentration interval is constructed according to the standard urea concentration that is not eliminated, and the indicator evaluation coefficient of the urea concentration requirement indicator is set according to the comprehensive standard urea concentration interval;

[0090] Predicting the target urea flow rate of all boiler injection areas according to each standard urea concentration in the comprehensive standard urea concentration range, inputting each standard urea concentration and the corresponding target urea flow rate of all boiler injection areas into a preset urea cost prediction model to obtain the predicted urea cost corresponding to the current standard urea concentration, constructing a standard urea cost range according to the predicted urea cost less than a preset urea cost threshold, and setting an indicator evaluation coefficient of the urea cost requirement indicator according to the standard urea cost range;

[0091] Obtain the historical configuration log of each standard urea concentration in the comprehensive standard urea concentration range, generate multiple historical stabilities of the corresponding standard urea concentration according to the historical configuration duration in the historical configuration log and the historical change characteristics of the corresponding standard urea concentration, generate a stability evaluation value of the historical stability of the current standard urea concentration according to the historical emission log corresponding to the historical configuration log, eliminate the historical stability whose stability evaluation value is less than a preset stability evaluation value threshold, and generate the standard stability range of the current standard urea concentration with the remaining historical stabilities;

[0092] The index evaluation coefficient of the urea concentration stability requirement index is set according to the standard stability interval of each standard urea concentration in the comprehensive standard urea concentration interval.

[0093] In this embodiment, the preset number threshold refers to 1 / 3 of the total number. The standard urea concentration of each boiler injection area is determined by the boiler load and nitrogen oxide content of the real-time operating parameters, and multiple standard urea concentrations are determined by the real-time operating parameters of multiple boiler injection areas, and the standard urea concentration difference between each standard urea concentration and the remaining standard urea concentrations is calculated, so as to determine a standard urea concentration with high applicability, and construct a comprehensive standard urea concentration range, that is, the urea concentration that meets the needs of most boiler injection areas, thereby improving the denitrification efficiency of multiple boiler injection areas.

[0094] In this embodiment, the historical change characteristics of the standard urea concentration include the change value, slope change rate and fluctuation degree within the historical configuration period. When the change value is larger, the slope change rate is larger or the fluctuation degree is larger, the historical stability is smaller, and vice versa, the historical stability is greater.

[0095] In this embodiment, by comprehensively analyzing the urea concentration, the required urea cost and the stability of the urea concentration and constructing a urea requirement index, the denitrification efficiency of the subsequent actual urea concentration is improved and the use cost is reduced.

[0096] In some embodiments of the present application, an index evaluation coefficient of the urea concentration requirement index corresponding to the standard urea concentration is set according to the standard urea concentration difference of the standard urea concentration in the comprehensive standard urea concentration interval;

[0097] The calculation formula of the index evaluation coefficient of the urea concentration requirement index is:

[0098]

[0099] Wherein, y1f is the index evaluation coefficient of the f-th standard urea concentration in the urea concentration requirement index, z1 is the first index evaluation conversion coefficient, n,f is the number of standard urea concentration difference values ​​of the f-th standard urea concentration that are greater than the preset difference threshold, m is the total number of standard urea concentrations, m-1 is the total number of standard urea concentration differences, △Ai,f is the i-th standard urea concentration difference value of the f-th annotated urea concentration;

[0100] The index evaluation coefficients of the standard urea concentrations in the comprehensive standard urea concentration range in the urea concentration requirement index are sorted according to size to obtain the index evaluation coefficient sequence Y1, Y1(y11, y21, ..., y1m) of the urea concentration requirement index, wherein y1f is the index evaluation coefficient of the f-th standard urea concentration, and y11<y21<...<y1m;

[0101] Divide the standard urea cost interval into multiple standard urea cost sub-intervals, sort each standard urea cost sub-interval according to size, and obtain a standard urea cost sub-interval sequence B, B(b1, b2, ..., bj), where bv is the vth standard urea cost sub-interval, and b1>b2>...>bj;

[0102] Each standard urea cost sub-interval in the standard urea cost sequence is configured with an index evaluation coefficient of a corresponding urea cost requirement index, and an index evaluation coefficient sequence Y2, Y2(y21, y22, ..., y2j) of the urea cost requirement index is obtained, wherein y2v is the index evaluation coefficient of the vth standard urea cost sub-interval, and y21<y22<...<y2j;

[0103] Divide the standard stability interval of each standard urea concentration in the comprehensive standard urea concentration interval into a plurality of standard stability subintervals, sort the standard stability subintervals of each standard stability interval according to size, and obtain a standard stability subinterval sequence C, C (c1, c2, ..., cg) corresponding to the standard urea concentration, wherein cx is the xth standard stability subinterval, and c1<c2<...<cg;

[0104] Each standard stability sub-interval in the standard stability sequence is configured with a corresponding indicator evaluation coefficient of the urea concentration stability requirement indicator, and an indicator evaluation coefficient sequence Y3, Y3 (y31, y32, ..., y3g) of the urea concentration requirement indicator is obtained, wherein y3x is the indicator evaluation coefficient of the x-th standard stability sub-interval, and y31<y32<...<y3g.

[0105] In this embodiment, the corresponding indicator evaluation coefficient sequence of the urea concentration requirement index, the indicator evaluation coefficient sequence of the urea cost requirement index and the indicator evaluation sequence of the urea concentration stability requirement index are respectively constructed for the comprehensive standard urea concentration interval, the standard urea cost interval and the standard stability interval of each standard urea concentration in the comprehensive standard urea concentration interval, and are set as urea requirement indicators, thereby laying a foundation for the subsequent determination of the indicator evaluation coefficient of the actual urea solution concentration, improving the evaluation accuracy of the actual urea solution concentration, and ensuring the denitrification efficiency of each boiler injection area, meeting emission standards and safe and economical operation.

[0106] In some embodiments of the present application, judging whether the preset urea requirement index is met according to the actual urea solution concentration includes:

[0107] Perform similarity analysis on the actual urea solution concentration and the standard urea concentration in the comprehensive standard urea concentration range, and set the index evaluation coefficient of the marked urea concentration with the greatest similarity to the actual urea solution concentration in the index evaluation coefficient sequence Y1 of the urea concentration requirement index as the actual index evaluation coefficient of the current actual urea solution concentration;

[0108] Predicting the actual urea flow rate of all boiler injection areas according to the actual urea solution concentration, inputting the actual urea solution concentration and the actual urea flow rate of all boiler injection areas into a preset urea cost prediction model to obtain a predicted urea cost of the actual urea solution concentration;

[0109] The predicted urea cost of the actual urea solution concentration is compared with the standard urea cost sub-interval in the standard urea cost sequence, and the index evaluation coefficient of the standard urea cost sub-interval in which the predicted urea cost of the actual urea solution concentration is located in the index evaluation coefficient sequence Y2 of the urea cost requirement index is set as the actual index evaluation coefficient of the predicted urea cost of the current actual urea solution concentration;

[0110] Acquire multiple actual urea solution concentrations within the control time of the control instruction, construct an actual urea solution concentration change curve, and generate an actual stability of the current actual urea solution concentration according to the actual change characteristics of the actual urea solution concentration in the actual urea solution concentration change curve;

[0111] Perform similarity analysis on the actual stability and the standard urea concentration in the comprehensive standard urea concentration interval, compare the standard stability sub-interval sequence of the standard stability interval of the standard urea concentration with the greatest similarity between the actual stability and the actual urea solution concentration, and set the index evaluation coefficient of the standard stability sub-interval where the actual stability is located in the index evaluation coefficient sequence Y3 of the urea concentration stability index as the actual index evaluation coefficient of the actual stability of the current actual urea solution concentration;

[0112] Generate a predicted denitration efficiency of each boiler injection area according to the actual urea solution concentration and the predicted urea flow rate allocated to each boiler injection area, compare the predicted denitration efficiency of each boiler injection area with the corresponding preset denitration efficiency threshold, and generate a compensation coefficient according to the comparison results of all boiler injection areas;

[0113] A comprehensive evaluation coefficient of a preset urea requirement index is generated according to actual index evaluation coefficients of the urea concentration requirement index, the urea cost requirement index, the urea concentration stability requirement index, and a compensation coefficient.

[0114] In this embodiment, the compensation coefficient is set based on comparing multiple predicted denitrification efficiencies with corresponding preset denitrification efficiency thresholds. The predicted denitrification efficiency is subtracted from the corresponding preset denitrification efficiency threshold to obtain a denitrification efficiency difference. When the multiple denitrification efficiency differences are positive and the larger the multiple denitrification efficiency differences are, the larger the compensation coefficient is. When the multiple denitrification efficiency differences are negative and the smaller the multiple denitrification efficiency differences are, the smaller the compensation coefficient is. The value range of the compensation coefficient is (0.75, 1.25).

[0115] In this embodiment, the actual urea solution concentration, the corresponding predicted urea cost and the corresponding actual stability are compared with the comprehensive standard urea concentration interval, the standard urea cost interval and the standard stability interval of each standard urea concentration in the comprehensive standard urea concentration interval, respectively, to determine the corresponding actual index evaluation coefficient, and conduct a comprehensive evaluation on the actual urea solution concentration to determine whether the current actual urea solution concentration meets the urea requirement index, that is, whether it meets the emission standards and denitrification efficiency under the premise of reducing the denitrification cost, so as to ensure the safe and economical operation of the boiler.

[0116] In some embodiments of the present application, the calculation formula of the comprehensive evaluation coefficient is:

[0117] Y=r×(y1f×d1+y2v×d2+y3x×d3);

[0118] Wherein, Y is the comprehensive evaluation coefficient, d1 is the weight coefficient of the urea concentration requirement index, d2 is the weight coefficient of the urea cost requirement index, d3 is the weight coefficient of the urea concentration stability requirement index, r is the compensation coefficient, and 0.75<r<1.25;

[0119] Pre-set comprehensive evaluation coefficient threshold;

[0120] When the comprehensive evaluation coefficient is less than the comprehensive evaluation coefficient threshold, the current actual urea concentration does not meet the preset urea requirement index, and a correction instruction is generated for the control parameter in the control instruction;

[0121] When the comprehensive evaluation coefficient is greater than the comprehensive evaluation coefficient threshold, the current actual urea concentration meets the preset urea requirement index, and no correction instruction is generated for the control parameters in the control instruction.

[0122] In some embodiments of the present application, generating a correction instruction of the control instruction according to the judgment result includes:

[0123] When the judgment result is that the current actual urea concentration does not meet the preset urea requirement index, the actual index evaluation coefficients of the urea concentration requirement index, the urea cost requirement index and the urea concentration stability requirement index are respectively compared with the maximum index evaluation coefficient in the corresponding index evaluation coefficient sequence, and the index deviation level is determined according to the comparison result;

[0124] A correction instruction of the control instruction is generated according to the index deviation level, and the correction instruction includes an opening adjustment range of one or more of the dilution water pipeline proportional valve and the urea solution water pipeline proportional valve.

[0125] In some embodiments of the present application, determining the indicator deviation level according to the comparison result includes:

[0126] The calculation formula of the indicator deviation level is:

[0127]

[0128] Wherein, P is the indicator deviation level, t1 is the first indicator deviation level conversion coefficient, y1m is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y1 of the urea concentration requirement indicator, y2j is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y2 of the urea cost requirement indicator, y3g is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y3 of the urea concentration stability requirement indicator, t2 is the second indicator deviation level conversion coefficient, t3 is the third indicator deviation level conversion coefficient, is the ceiling rounding function;

[0129] The opening adjustment range T is: T=P×1%.

[0130] In this embodiment, the deviation level of each required indicator is obtained by subtracting the actual indicator evaluation coefficient corresponding to the urea concentration requirement index, the urea cost requirement index and the urea concentration stability requirement index from the maximum indicator evaluation coefficient, and the current indicator deviation level is comprehensively determined. The opening adjustment range of the corresponding proportional valve is set according to the size of the indicator deviation level and the specific deviation situation to ensure the control accuracy of urea concentration, improve the denitrification efficiency and ensure the safe and economical operation of the boiler.

[0131] In some embodiments of the present application, Figure 2 As shown, it also includes a method for controlling urea concentration in a denitrification process:

[0132] Step S201: setting a monitoring time interval for each boiler injection area, and obtaining real-time operating parameters of the corresponding boiler injection area according to the monitoring time interval;

[0133] Step S202: generating a control instruction for the urea solution in the static mixer according to the real-time operating parameters;

[0134] Step S203: presetting a urea requirement index, obtaining the actual urea solution concentration after the control instruction, and determining whether the actual urea solution concentration meets the urea requirement index;

[0135] Step S204: Generate a correction instruction for the control parameter in the control instruction according to the judgment result.

[0136] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present application. These improvements and substitutions should also be regarded as the scope of protection of the present application.

Claims

1. A urea concentration control system in a denitrification process, characterized in that: include: An acquisition module, used to set a monitoring time interval for each boiler injection area, and acquire real-time operating parameters of the corresponding boiler injection area according to the monitoring time interval; A generation module, used for generating control instructions for the urea solution in the static mixer according to real-time operating parameters; A judgment module is used to pre-set the urea requirement index, obtain the actual urea solution concentration after the control instruction, and judge whether the actual urea solution concentration meets the urea requirement index; The control module is used to generate a correction instruction for the control parameters in the control instruction according to the judgment result.

2. The urea concentration control system in the denitration process according to claim 1, characterized in that: Set monitoring intervals for each boiler injection zone, including: Obtaining historical operating parameters of each boiler injection area in the previous adjacent preset time period, wherein the historical operating parameters include boiler load, nitrogen oxide content, and fuel quantity; Constructing a first change curve, a second change curve and a third change curve in the previous adjacent preset time period respectively according to the boiler load, the nitrogen oxide content and the fuel amount; determining a first change degree of boiler load according to the first change curve, determining a second change degree of nitrogen oxide content according to the second change curve, and determining a third change degree of fuel amount according to the third change curve; A comprehensive degree of change is determined according to the first degree of change, the second degree of change and the third degree of change, and a monitoring time interval corresponding to the boiler injection area is set according to the comprehensive degree of change.

3. The urea concentration control system in the denitration process according to claim 2, characterized in that: Generate control instructions for urea solution in the static mixer based on real-time operating parameters, including: Acquire the real-time operating parameters of each boiler injection area according to the monitoring time interval, input the real-time operating parameters into the urea concentration prediction model trained in advance for each boiler injection area, and obtain multiple predicted urea concentrations; Comprehensively analyze multiple predicted urea concentrations to determine the characteristic urea concentration; A control instruction is generated according to the characteristic urea concentration, and the control parameters in the control instruction include the real-time opening of the dilution water pipeline proportional valve and the urea solution water pipeline proportional valve.

4. The urea concentration control system in the denitration process according to claim 3, characterized in that: Pre-set urea requirements, including: The urea requirement index includes a urea concentration requirement index, a urea cost requirement index and a urea concentration stability requirement index; Generate a standard urea concentration of the corresponding boiler injection area according to the real-time operating parameters of each boiler injection area, and subtract each standard urea concentration from the remaining standard urea concentrations to obtain multiple standard urea concentration difference values ​​of each standard urea concentration; If the standard urea concentration difference of the current standard urea concentration is greater than the preset difference threshold and the number of standard urea concentration difference values ​​greater than the preset difference threshold is greater than the preset number threshold, the current standard urea concentration is eliminated, and a comprehensive standard urea concentration interval is constructed according to the standard urea concentration that is not eliminated, and the indicator evaluation coefficient of the urea concentration requirement indicator is set according to the comprehensive standard urea concentration interval; Predicting the target urea flow rate of all boiler injection areas according to each standard urea concentration in the comprehensive standard urea concentration range, inputting each standard urea concentration and the corresponding target urea flow rate of all boiler injection areas into a preset urea cost prediction model to obtain the predicted urea cost corresponding to the current standard urea concentration, constructing a standard urea cost range according to the predicted urea cost less than a preset urea cost threshold, and setting an indicator evaluation coefficient of the urea cost requirement indicator according to the standard urea cost range; Obtain the historical configuration log of each standard urea concentration in the comprehensive standard urea concentration range, generate multiple historical stabilities of the corresponding standard urea concentration according to the historical configuration duration in the historical configuration log and the historical change characteristics of the corresponding standard urea concentration, generate a stability evaluation value of the historical stability of the current standard urea concentration according to the historical emission log corresponding to the historical configuration log, eliminate the historical stability whose stability evaluation value is less than a preset stability evaluation value threshold, and generate the standard stability range of the current standard urea concentration with the remaining historical stabilities; The index evaluation coefficient of the urea concentration stability requirement index is set according to the standard stability interval of each standard urea concentration in the comprehensive standard urea concentration interval.

5. The urea concentration control system in the denitration process according to claim 4, characterized in that: According to the standard urea concentration difference of the standard urea concentration in the comprehensive standard urea concentration range, an index evaluation coefficient of the corresponding standard urea concentration in the urea concentration requirement index is set; The calculation formula of the index evaluation coefficient of the urea concentration requirement index is: Wherein, y1f is the index evaluation coefficient of the f-th standard urea concentration in the urea concentration requirement index, z1 is the first index evaluation conversion coefficient, n,f is the number of standard urea concentration difference values ​​of the f-th standard urea concentration that are greater than the preset difference threshold, m is the total number of standard urea concentrations, m-1 is the total number of standard urea concentration differences, △Ai,f is the i-th standard urea concentration difference value of the f-th annotated urea concentration; The index evaluation coefficients of the standard urea concentrations in the comprehensive standard urea concentration range in the urea concentration requirement index are sorted according to size to obtain the index evaluation coefficient sequence Y1, Y1(y11, y21, ..., y1m) of the urea concentration requirement index, wherein y1f is the index evaluation coefficient of the f-th standard urea concentration, and y11<y21<...<y1m; Divide the standard urea cost interval into multiple standard urea cost sub-intervals, sort each standard urea cost sub-interval according to size, and obtain a standard urea cost sub-interval sequence B, B(b1, b2, ..., bj), where bv is the vth standard urea cost sub-interval, and b1>b2>...>bj; Each standard urea cost sub-interval in the standard urea cost sequence is configured with an index evaluation coefficient of a corresponding urea cost requirement index, and an index evaluation coefficient sequence Y2, Y2(y21, y22, ..., y2j) of the urea cost requirement index is obtained, wherein y2v is the index evaluation coefficient of the vth standard urea cost sub-interval, and y21<y22<...<y2j; Divide the standard stability interval of each standard urea concentration in the comprehensive standard urea concentration interval into a plurality of standard stability subintervals, sort the standard stability subintervals of each standard stability interval according to size, and obtain a standard stability subinterval sequence C, C (c1, c2, ..., cg) corresponding to the standard urea concentration, wherein cx is the xth standard stability subinterval, and c1<c2<...<cg; Each standard stability sub-interval in the standard stability sequence is configured with a corresponding indicator evaluation coefficient of the urea concentration stability requirement indicator, and an indicator evaluation coefficient sequence Y3, Y3 (y31, y32, ..., y3g) of the urea concentration requirement indicator is obtained, wherein y3x is the indicator evaluation coefficient of the x-th standard stability sub-interval, and y31<y32<...<y3g.

6. The urea concentration control system in the denitration process according to claim 5, characterized in that: Determine whether the preset urea requirement indicators are met based on the actual urea solution concentration, including: Perform similarity analysis on the actual urea solution concentration and the standard urea concentration in the comprehensive standard urea concentration range, and set the index evaluation coefficient of the marked urea concentration with the greatest similarity to the actual urea solution concentration in the index evaluation coefficient sequence Y1 of the urea concentration requirement index as the actual index evaluation coefficient of the current actual urea solution concentration; Predicting the actual urea flow rate of all boiler injection areas according to the actual urea solution concentration, inputting the actual urea solution concentration and the actual urea flow rate of all boiler injection areas into a preset urea cost prediction model to obtain a predicted urea cost of the actual urea solution concentration; The predicted urea cost of the actual urea solution concentration is compared with the standard urea cost sub-interval in the standard urea cost sequence, and the index evaluation coefficient of the standard urea cost sub-interval in which the predicted urea cost of the actual urea solution concentration is located in the index evaluation coefficient sequence Y2 of the urea cost requirement index is set as the actual index evaluation coefficient of the predicted urea cost of the current actual urea solution concentration; Acquire multiple actual urea solution concentrations within the control time of the control instruction, construct an actual urea solution concentration change curve, and generate an actual stability of the current actual urea solution concentration according to the actual change characteristics of the actual urea solution concentration in the actual urea solution concentration change curve; Perform similarity analysis on the actual stability and the standard urea concentration in the comprehensive standard urea concentration interval, compare the standard stability sub-interval sequence of the standard stability interval of the standard urea concentration with the greatest similarity between the actual stability and the actual urea solution concentration, and set the index evaluation coefficient of the standard stability sub-interval where the actual stability is located in the index evaluation coefficient sequence Y3 of the urea concentration stability index as the actual index evaluation coefficient of the actual stability of the current actual urea solution concentration; Generate a predicted denitration efficiency of each boiler injection area according to the actual urea solution concentration and the predicted urea flow rate allocated to each boiler injection area, compare the predicted denitration efficiency of each boiler injection area with the corresponding preset denitration efficiency threshold, and generate a compensation coefficient according to the comparison results of all boiler injection areas; A comprehensive evaluation coefficient of a preset urea requirement index is generated according to actual index evaluation coefficients of the urea concentration requirement index, the urea cost requirement index, the urea concentration stability requirement index, and a compensation coefficient.

7. The urea concentration control system in the denitration process according to claim 6, characterized in that: The calculation formula of the comprehensive evaluation coefficient is: Y=r×(y1f×d1+y2v×d2+y3x×d3); Wherein, Y is the comprehensive evaluation coefficient, d1 is the weight coefficient of the urea concentration requirement index, d2 is the weight coefficient of the urea cost requirement index, d3 is the weight coefficient of the urea concentration stability requirement index, r is the compensation coefficient, and 0.75<r<1.25; Pre-set comprehensive evaluation coefficient threshold; When the comprehensive evaluation coefficient is less than the comprehensive evaluation coefficient threshold, the current actual urea concentration does not meet the preset urea requirement index, and a correction instruction is generated for the control parameter in the control instruction; When the comprehensive evaluation coefficient is greater than the comprehensive evaluation coefficient threshold, the current actual urea concentration meets the preset urea requirement index, and no correction instruction is generated for the control parameters in the control instruction.

8. The urea concentration control system in the denitration process according to claim 7, characterized in that: Generate a correction instruction of the control instruction according to the judgment result, including: When the judgment result is that the current actual urea concentration does not meet the preset urea requirement index, the actual index evaluation coefficients of the urea concentration requirement index, the urea cost requirement index and the urea concentration stability requirement index are respectively compared with the maximum index evaluation coefficient in the corresponding index evaluation coefficient sequence, and the index deviation level is determined according to the comparison result; A correction instruction of the control instruction is generated according to the index deviation level, and the correction instruction includes an opening adjustment range of one or more of the dilution water pipeline proportional valve and the urea solution water pipeline proportional valve.

9. The urea concentration control system in the denitration process according to claim 8, characterized in that: Determine the indicator deviation level based on the comparison results, including: The calculation formula of the indicator deviation level is: Wherein, P is the indicator deviation level, t1 is the first indicator deviation level conversion coefficient, y1m is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y1 of the urea concentration requirement indicator, y2j is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y2 of the urea cost requirement indicator, y3g is the maximum indicator evaluation coefficient in the indicator evaluation coefficient sequence Y3 of the urea concentration stability requirement indicator, t2 is the second indicator deviation level conversion coefficient, t3 is the third indicator deviation level conversion coefficient, is the ceiling rounding function; The opening adjustment range T is: T=P×1%.

10. A method for controlling urea concentration in a denitrification process, characterized in that: include: Set a monitoring time interval for each boiler injection area, and obtain real-time operating parameters of the corresponding boiler injection area according to the monitoring time interval; Generate control instructions for urea solution in the static mixer according to real-time operating parameters; Preset the urea requirement index, obtain the actual urea solution concentration after the control instruction, and judge whether the actual urea solution concentration meets the urea requirement index; Generate a correction instruction for the control parameter in the control instruction according to the judgment result.

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