A waste incinerator secondary pollutant in-furnace coupling removal system and control method

Abstract

The present invention discloses a system and control method for coupling removal of secondary pollutants in a waste incinerator, wherein the system includes: a fuel regulating module, which is arranged at the fuel inlet of the waste incinerator; a primary and secondary air regulating module, wherein the primary air regulating module is arranged below the grate, and the secondary air regulating module is arranged at the front and rear arches above the furnace; a temperature detection module, including a first furnace temperature detection module, a second furnace temperature detection module and a superheater temperature detection module; an SNCR regulating module, which is connected to the SNCR spray gun control valve; a secondary pollutant detection module, which is arranged at the flue gas discharge; and a database, which is used to pre-process and store data, and form decision instructions. The present invention realizes the control of the output of secondary pollutants at the source, solves the problem of sudden excessive emission of pollutants at the current stage, reduces the amount of reducing agent and reduces the generation of pollutants from the source, and can be widely used in the field of secondary pollutant removal and emission technology.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary pollutant removal and emission, and in particular to a secondary pollutant removal system and a control method in a waste incinerator. Background Art

[0002] The process of removing secondary pollutants from flue gas of waste incinerators mainly consists of independent systems such as denitrification, deacidification, dust removal, dioxin and heavy metal removal. In addition, manual operation and automatic control modes are mainly used in the denitrification and desulfurization processes at this stage, but both modes rely on the detection indicators of tail flue gas, which have lags, and the volatility of the fuel characteristics of waste incinerators is large, which easily causes the mismatch of reducing agents. Therefore, in the process of deacidification and denitrification, it is impossible to achieve effective coordination between the emission of secondary pollutants in flue gas and the inhibition process, resulting in the following problems:

[0003] (1) Excessive pollutant emissions: Due to the large fluctuations in fuel properties and the lag in the linkage between emission detection indicators and deacidification and denitrification processes, sudden emissions exceed the standards, affecting the controllability of emissions.

[0004] (2) Increasing the cost of reducing agents and deacidification agents: In order to avoid sudden emissions exceeding the standard and the limitations of reducing agent and deacidification agent process adjustment, it is necessary to increase the dosage to reduce emissions and ensure environmental protection indicators.

[0005] (3) It is difficult to control the production of secondary pollutants at the source, especially NO X The production of HCl causes corrosion of process equipment during the flow of flue gas. Summary of the invention

[0006] In order to solve at least one of the technical problems existing in the prior art to a certain extent, the object of the present invention is to provide a system and a control method for removing secondary pollutants in a waste incinerator through in-furnace coupling.

[0007] The technical solution adopted by the present invention is:

[0008] A waste incinerator secondary pollutant in-furnace coupled removal system, comprising:

[0009] A fuel regulating module is arranged at the fuel inlet of the waste incinerator;

[0010] The primary and secondary air regulating modules include a primary air regulating module and a secondary air regulating module, wherein the primary air regulating module is arranged below the grate, and the secondary air regulating module is arranged at the front and rear arches above the furnace;

[0011] The temperature detection module includes a first furnace temperature detection module, a second furnace temperature detection module and a superheater temperature detection module;

[0012] SNCR regulating module, connected to the SNCR spray gun control valve;

[0013] A secondary pollutant detection module is installed at the smoke emission point;

[0014] Databases, including operation databases, historical databases and CFD three-dimensional simulation databases, are used to pre-process and store data and form decision-making instructions.

[0015] Furthermore, the fuel regulating module is connected to the feeder and is used to adjust the thickness of the fuel, the speed of the grate and the amount of sludge mixed according to the decision instructions issued by the database.

[0016] Further, the primary air regulating module is connected to the electric damper of each grate below the grate, and the secondary air regulating module is connected to the electric damper of each grate above the furnace;

[0017] The connection between the primary and secondary air regulating modules and the electric damper includes electrical connection and signal connection, wherein the signal in the signal connection is a decision instruction of the database.

[0018] Further, the first furnace temperature detection module is arranged at the middle of the furnace, the second furnace temperature detection module is arranged at the top of the furnace, and the superheater temperature detection module is arranged at the front end of the superheater;

[0019] The temperature detection value of the temperature detection module is stored in the operation database.

[0020] Furthermore, the SNCR regulating module is used to adjust the flow rate and injection position of the SNCR spray gun according to the decision instructions of the database.

[0021] Furthermore, the data collected by the secondary pollutant detection module is stored in an operation database.

[0022] Furthermore, the preprocessing of the data includes: cleaning unreasonable data in the acquired data, wherein the unreasonable data includes erroneous data, abnormal data and duplicate data.

[0023] Another technical solution adopted by the present invention is:

[0024] The control method of the in-furnace coupling removal system of secondary pollutants in a garbage incinerator as described above comprises the following steps:

[0025] S1. The database cleans historical data, CFD three-dimensional simulation data and operation data to obtain sample data;

[0026] S2. Selecting feature variables, wherein the feature variables include original feature variables and reconstructed feature variables;

[0027] S3. According to the sample data, the data value of the reconstructed characteristic variable is calculated by a characteristic variable reconstruction method to generate a decision instruction;

[0028] S4. According to the operation result of the decision instruction, repeat steps S1-S3 to construct a decision instruction for the in-furnace coupled removal of secondary pollutants.

[0029] Furthermore, the step S2 comprises:

[0030] S21. Analyze the generation mechanism and historical data of secondary pollutants in the waste incinerator to determine the influencing factors affecting the emission of secondary pollutants, and determine the original characteristic variables of different adjustment modules based on the influencing factors;

[0031] S22, reconstructing the original feature variables to determine the reconstructed feature variables;

[0032] S22: Use the sample data to perform correlation analysis and importance calculation on each original characteristic variable and the reconstructed characteristic variable, and select characteristic variables for decision instructions of each adjustment module.

[0033] Furthermore, the original characteristic variables and the reconstructed characteristic variables include: temperature, temperature change, secondary pollutant emissions, and secondary pollutant emission changes.

[0034] The beneficial effects of the present invention are as follows: the present invention uses furnace temperature detection, furnace top temperature detection and superheater temperature detection data as adjustment action feedback, and analyzes and evaluates the secondary pollutant data detection results; it realizes the effective coordination of the emission of flue gas secondary pollutants and the suppression process, effectively solves the large fluctuations in fuel properties, and excessive increase in the amount of reducing agent and deacidification agent when sudden emissions exceed the standard, thereby controlling the output of secondary pollutants at the source, and is suitable for sludge blending incineration conditions, providing online monitoring and offline guidance and strategies for the coupled control of waste incinerator operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the embodiments of the present invention or the drawings of related technical solutions in the prior art are introduced below. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 This is a simplified structural diagram of a system for removing secondary pollutants in a waste incinerator coupled with a furnace in an embodiment of the present invention;

[0037] Figure 2It is a control flow chart of a secondary pollutant in-furnace coupling removal system of a waste incinerator in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limitations of the present invention. For the step numbers in the following embodiments, they are only provided for the convenience of explanation, and the order between the steps is not limited in any way, and the execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0039] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 invention.

[0040] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0041] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0042] like Figure 1 and Figure 2 As shown, this embodiment provides a waste incinerator secondary pollutant in-furnace coupled removal system to reduce secondary pollutant emissions from the source, including:

[0043] The fuel regulating module is placed at the fuel inlet of the waste incinerator and connected to the feeder;

[0044] The primary and secondary air regulating modules include a primary air regulating module and a secondary air regulating module, wherein the primary air regulating module is placed below the grate and connected to the electric dampers of each grate; the secondary air regulating module is arranged at the front and rear arches above the furnace and connected to the electric dampers;

[0045] The temperature detection module includes a first furnace temperature detection module (corresponding to Figure 2 The temperature detection module 1 in the furnace), the second furnace temperature detection module (corresponding to Figure 2 The temperature detection module 3) and the superheater temperature detection module (corresponding to Figure 2 Temperature detection module 3);

[0046] SNCR regulating module, connected to the SNCR spray gun control valve;

[0047] The secondary pollutant detection module is installed at the smoke emission point;

[0048] Database, including operation database, historical database and CFD three-dimensional simulation database.

[0049] To further explain, the fuel regulation module, primary and secondary air regulation module, temperature detection module, SNCR regulation module, and secondary pollutant detection module in the secondary pollutant furnace coupling removal system are respectively connected to the database, and the connection methods include electrical connection and signal connection.

[0050] The fuel regulating module is placed at the fuel inlet of the garbage incinerator and connected to the feeder, and regulates the thickness of the fuel, the speed of the grate and the amount of sludge mixed according to the decision instructions formed by the database.

[0051] As an optional implementation, the thickness of the fuel is mainly adjusted according to the calorific value of the garbage, the furnace temperature, and the distribution ratio of the primary air, and the thickness of the material layer of the first-stage grate ranges from 500mm to 1000mm.

[0052] As an optional implementation, the primary air regulating module and the secondary air regulating module are respectively connected to the corresponding electric dampers, and the connection method includes electrical connection and signal connection, and the signal in the signal connection is the decision instruction of the database. Specifically, after receiving the decision instruction of the database, the primary air regulating module and the secondary air regulating module adjust the opening of the electric damper to adjust the air volume of the primary air and the secondary air, and the total air volume = primary air volume + secondary air volume. Among them, the air volume of the primary air is configured in stages according to the movement speed of the grate and the number of levels of the grate, in order to adjust the ignition point position of the grate and ensure the burnout rate at the same time.

[0053] To further explain, the basic data for forming decision instructions from the database includes an operation database, a history database and a CFD three-dimensional simulation database, and the decision instructions formed are to adjust the grate temperature by adjusting the feed amount of fuel.

[0054] As an optional implementation, the operation database is the real-time operation parameters of the DCS system, and the data of the CFD three-dimensional simulation database is valid data verified by the actual operation parameter model.

[0055] See also Figure 1 , further explained, the temperature detection module includes a first furnace temperature detection module, a second furnace temperature detection module and a superheater temperature detection module, the first furnace temperature detection module is arranged in the middle of the furnace (such as Figure 1 The second furnace temperature detection module is set at the top of the furnace (as shown in the middle temperature detection point 1), and the second furnace temperature detection module is set at the top of the furnace (as shown in the middle temperature detection point 1). Figure 1 The superheater temperature detection module is set at the front end of the superheater (as shown in the middle temperature detection point 2). Figure 1 The temperature detection values ​​of each temperature detection module are stored in the operation data database.

[0056] The detection value of temperature detection module 1 is used as the original characteristic variable for adjusting the SNCR injection position, the detection value of temperature detection module 2 is used as the original characteristic variable for adjusting the SNCR injection amount, and the detection value of temperature detection module 3 is used as the original characteristic variable for superheater overtemperature protection.

[0057] As an optional implementation, when the detection value of the temperature detection module 1 exceeds 850°C, a first-level warning will be activated. When the temperature change rate is greater than 5-20°C, a second-level warning will be activated and characteristic variables will be reconstructed.

[0058] The SNCR regulating module is connected to the SNCR spray gun control valve, wherein the SNCR regulating module regulates the flow rate and the injection position of the SNCR spray gun according to the decision instructions of the database.

[0059] As an optional embodiment, the flow rate of the reducing agent is calculated according to the NOx emission at the outlet, and the ratio of the reducing agent to the ammonia nitrogen in the flue gas is in the range of 1.1 to 1.8, wherein the concentration of NOx in the flue gas (dry basis, standard state, 6% O 2 ) is calculated as:

[0060]

[0061] Where:

[0062] NO x (mg / Nm 3 ): NOx concentration under standard conditions, 6% oxygen content, dry flue gas, mg / m 3 ;

[0063] NO (μL / L): measured NO volume content in dry flue gas, ppm;

[0064] O 2 : Measured oxygen content in dry flue gas, %.

[0065] The SNCR regulating module and the SNCR spray gun control valve are mainly connected by electrical connection and signal connection, wherein the signal source in the signal connection is the decision instruction of the database.

[0066] Further explanation: the secondary pollutant detection module is set at the flue gas emission, wherein the collected data of the secondary pollutant detection module is stored in the operation database. The collected data of the secondary pollutant detection module mainly includes: particulate matter, nitrogen oxides, sulfur dioxide, hydrogen chloride, carbon monoxide and other influencing factors.

[0067] As an optional implementation, the database is used to preprocess and store data, and form decision instructions, wherein the data preprocessing specifically refers to cleaning unreasonable data in the acquired data, and the unreasonable data includes erroneous data, abnormal data and duplicate data.

[0068] Specifically, the erroneous data mainly refers to data collected by the terminal device due to errors or mutations, which are corrected by fitting methods. Abnormal data includes null data and data that deviates by more than 50%, and interpolation methods are used to replace and correct the data. The repeated data refers to the same data and data that appears 5 times or more within 30 minutes. By preprocessing the acquired historical data, it is possible to avoid interference from erroneous data when building the model, effectively improve the quality of the data, improve the prediction effect and accuracy of the model, reduce repeated data, and thus improve the modeling and prediction efficiency of the prediction model.

[0069] like Figure 2 As shown, based on the above-mentioned in-furnace coupling removal system for secondary pollutants in a waste incinerator, this embodiment also provides a control method, including the following steps:

[0070] Step S1: The database is cleaned according to historical data, CFD three-dimensional simulation data and operation data to obtain sample data.

[0071] Step S2: Select characteristic variables, which include original characteristic variables and reconstructed characteristic variables. The original characteristic variables and reconstructed characteristic variables include: temperature, temperature change, secondary pollutant emission, secondary pollutant emission change, etc.

[0072] Step S2 specifically includes steps S21-S23:

[0073] Step S21, determination of original characteristic variables and reconstructed characteristic variables: according to the generation mechanism of secondary pollutants in the furnace and the analysis of historical data, the influencing factors affecting the emission of secondary pollutants are determined, and the original characteristic variables of different adjustment modules are determined according to the influencing factors;

[0074] Step S22: Reconstruct the original characteristic variables according to the generation mechanism of secondary pollutants and the analysis of historical data to determine the reconstructed characteristic variables.

[0075] Step S23: using the sample data to perform correlation analysis and importance calculation on each original characteristic variable and reconstructed characteristic variable, and selecting characteristic variables for decision instructions of each adjustment module;

[0076] Step S3, establishing a decision instruction: using the sample data to calculate and reconstruct the data value of the characteristic variable through the characteristic variable reconstruction method to generate a decision instruction;

[0077] Step S4: according to the running result of the decision instruction for in-furnace coupling removal of secondary pollutants of steps S1-S3, repeat steps S1-S3 to construct the decision instruction for in-furnace coupling removal of secondary pollutants.

[0078] Specifically, the in-furnace coupled removal decision instructions for secondary pollutants are mainly for adjusting the feed amount, adjusting the air volume of the primary and secondary air, the SNCR injection position and injection amount, the monitoring and early warning values ​​of secondary pollutants, and the removal decision instructions are based on the data collected by the secondary pollutant detection module, the first furnace temperature detection module, the second furnace temperature detection module and the superheater temperature detection module. All collected data are stored in the operation result database.

[0079] In summary, this embodiment provides a waste incinerator secondary pollutant in-furnace coupling removal system which is equivalent to the prior art and has the following beneficial effects:

[0080] (1) This embodiment provides a system for the in-furnace coupled removal of secondary pollutants in a waste incinerator. The fuel adjustment module adjusts the fuel feed amount and the mixing ratio of sludge and waste, optimizes the ratio of primary air and secondary air, improves combustion efficiency and reduces the generation of secondary pollutants, especially NOx. At the same time, combined with the detection and prediction of the temperature detection module and the SNCR process, the denitrification efficiency is improved and the amount of reducing agent is reduced, thereby achieving in-furnace coupled removal of secondary pollutants. The system can achieve NO X Generation control at the source, refined control of SNCR and efficient mixing and incineration in the furnace can obtain the prediction results of secondary pollutant emissions, provide advance guidance for manual operations, solve the current problem of sudden excessive emissions of pollutants, reduce the amount of reducing agents and reduce the generation of pollutants from the source.

[0081] (2) The optimized operation database is established by combining the historical operation data with the three-dimensional numerical simulation method. Combined with the characteristic signal feedback, the optimized classification of primary and secondary air, the optimized adjustment of SNCR nozzles and the dynamic optimization parameters of sludge blending ratio are obtained, which can achieve NO XGeneration control at the source, refined SNCR control, and efficient incineration in the furnace. Artificial neural networks are used to predict the in-furnace coupling removal strategies and implementation measures for secondary pollutants corresponding to different incinerators, and the prediction results of ultra-low emissions of secondary pollutants are obtained.

[0082] (3) The present invention determines characteristic variables based on the analysis of operation data, historical data and CFD three-dimensional simulation data, and reconstructs the characteristic variables to form reconstructed characteristic variables, mainly including: temperature, temperature change, secondary pollutant emission, secondary pollutant emission change, and finally constructs the secondary pollutant furnace coupling removal decision instructions to form the feed amount, primary air, secondary air, SNCR injection amount, SNCR injection position linkage adjustment to achieve the coupling removal of secondary pollutants. The advance guidance of manual operation is achieved through offline mode, which solves the problem of sudden excessive emission of pollutants at this stage, reduces the amount of reducing agent and reduces the generation of pollutants from the source. It has the advantages of strong adaptability, good self-learning ability, high fitting accuracy, and significant optimization effect.

[0083] In the above description of this specification, the description with reference to the terms "one embodiment / example", "another embodiment / example" or "certain embodiments / examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0084] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0085] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A waste incinerator secondary pollutant in-furnace coupling removal system, characterized in that: include: The fuel regulating module is arranged at the fuel inlet of the waste incinerator and is used to adjust the thickness of the fuel, the movement speed of the grate and the amount of sludge mixed according to the decision instructions formed by the database; The primary and secondary air regulating modules include a primary air regulating module and a secondary air regulating module, wherein the primary air regulating module is arranged below the grate and connected to the electric air doors of the multiple grates, and the secondary air regulating module is arranged at the front and rear arches above the furnace; wherein the air volume of the primary air is configured in stages according to the movement speed of the grate and the number of stages of the grate; The temperature detection module comprises a first furnace temperature detection module, a second furnace temperature detection module and a superheater temperature detection module; the first furnace temperature detection module is arranged at the middle of the furnace, the second furnace temperature detection module is arranged at the top of the furnace, and the superheater temperature detection module is arranged at the front end of the superheater; wherein the detection value of the first furnace temperature detection module is used as the original characteristic variable for adjusting the injection position of the SNCR, the detection value of the second furnace temperature detection module is used as the original characteristic variable for adjusting the injection amount of the SNCR, and the detection value of the superheater temperature detection is used as the original characteristic variable for the over-temperature protection of the superheater; An SNCR regulating module is connected to the SNCR spray gun control valve; wherein the position of the SNCR nozzle is set between the installation position of the first furnace temperature detection module and the installation position of the second furnace temperature detection module, and the SNCR regulating module adjusts the flow rate and injection position of the SNCR spray gun according to the decision instruction of the database; A secondary pollutant detection module is arranged at the smoke emission location; wherein the collected data of the secondary pollutant detection module is stored in the operation database; Databases, including operation databases, historical databases, and CFD three-dimensional simulation databases, are used to pre-process and store data and form decision-making instructions; The temperature detection value of the temperature detection module is stored in the operation database.

2. According to claim 1, a waste incinerator secondary pollutant removal system is characterized in that: The fuel regulating module is connected to the feeder and is used to adjust the thickness of the fuel, the speed of the grate and the amount of sludge mixed according to the decision instructions issued by the database.

3. The in-furnace coupling removal system for secondary pollutants in a waste incinerator according to claim 1 is characterized in that: The primary air regulating module is connected to the electric dampers of each grate below the grate, and the secondary air regulating module is connected to the electric dampers of each grate above the furnace; The connection between the primary and secondary air regulating modules and the electric damper includes electrical connection and signal connection, wherein the signal in the signal connection is a decision instruction of the database.

4. A waste incinerator secondary pollutant removal system according to claim 1, characterized in that: The SNCR regulating module is used to adjust the flow rate and injection position of the SNCR spray gun according to the decision instructions of the database.

5. The in-furnace coupling removal system for secondary pollutants in a waste incinerator according to claim 1 is characterized in that: The data collected by the secondary pollutant detection module is stored in the operation database.

6. The in-furnace coupling removal system for secondary pollutants in a waste incinerator according to claim 1 is characterized in that: The preprocessing of the data includes: cleaning unreasonable data in the acquired data, wherein the unreasonable data includes erroneous data, abnormal data and duplicate data.

7. A control method for a secondary pollutant removal system in a waste incinerator according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. The database cleans historical data, CFD three-dimensional simulation data and operation data to obtain sample data; S2. Selecting feature variables, wherein the feature variables include original feature variables and reconstructed feature variables; S3. According to the sample data, a data value of a reconstructed characteristic variable is calculated by a characteristic variable reconstruction method to generate a decision instruction; S4. According to the operation result of the decision instruction, repeat steps S1-S3 to construct a decision instruction for the in-furnace coupled removal of secondary pollutants.

8. The control method according to claim 7, characterized in that: The step S2 comprises: S21. Analyze the generation mechanism and historical data of secondary pollutants in the waste incinerator to determine the influencing factors affecting the emission of secondary pollutants, and determine the original characteristic variables of different adjustment modules based on the influencing factors; S22, reconstructing the original feature variables to determine the reconstructed feature variables; S22: Use the sample data to perform correlation analysis and importance calculation on each original characteristic variable and the reconstructed characteristic variable, and select characteristic variables for decision instructions of each adjustment module.

9. The control method according to claim 8, characterized in that: The original characteristic variables and the reconstructed characteristic variables include: temperature, temperature change, secondary pollutant emissions, and secondary pollutant emission changes.

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