CN-122015102-A - Intelligent emission control and diagnosis system for waste incineration power plant

CN122015102ACN 122015102 ACN122015102 ACN 122015102ACN-122015102-A

Abstract

The invention relates to the technical field of waste incineration power generation, and discloses an intelligent emission control and diagnosis system for a waste incineration power plant. The central control unit adopts a time-sharing multiplexing logic, utilizes an acousto-optic cross-modal coupling correction algorithm to reconstruct a three-dimensional temperature field, a dielectric constant field and a gas concentration field in a hearth in a measurement time slot, and identifies a nitrogen oxide generation potential area and a mixed dead area based on multi-field feature fusion diagnosis in an execution time slot, drives a matrix type track-changing spray gun to spray a target reducing agent on the potential area according to the detection result, controls an acoustic wave receiving and transmitting array to switch to an excitation mode, and induces acoustic turbulence in the mixed dead area to enhance mixing. The invention realizes accurate monitoring and regional targeting treatment in a heterogeneous combustion environment, and effectively reduces the consumption of reducing agent and the escape of ammonia.

Inventors

WEI TIANLIN
CHEN XILIANG
SUN NIANCHAO
LIU ZHAOHUI

Assignees

新沂高能环保能源有限公司

Dates

Publication Date: 20260512
Application Date: 20260331

Claims (10)

1. The intelligent emission control and diagnosis system for the garbage incineration power plant is characterized by comprising an acoustic wave receiving and transmitting array, a capacitance tomography sensor array, a laser grid monitoring unit, a matrix type track-changing spray gun array and a central control unit; The central control unit is respectively in communication connection with the acoustic wave receiving and transmitting array, the capacitance tomography sensor array, the laser grid monitoring unit and the matrix type track-changing spray gun array; the central control unit is configured with time division multiplexing logic, and divides the working period of the system into measurement time slots and execution time slots which are not overlapped with each other; in the measurement time slot, the central control unit sends synchronous trigger signals to the acoustic wave receiving and transmitting array, the capacitance tomography sensor array and the laser grid monitoring unit to acquire acoustic measurement vectors, capacitance measurement vectors and spectrum measurement data sets, and three-dimensional temperature field distribution data, three-dimensional dielectric constant field distribution data and three-dimensional gas concentration field distribution data in a hearth are obtained through reconstruction by using a physical field inversion algorithm; And in the execution time slot, the central control unit performs multi-field feature fusion diagnosis based on the three-dimensional temperature field distribution data, the three-dimensional dielectric constant field distribution data and the three-dimensional gas concentration field distribution data, identifies a nitrogen oxide generation potential area and a mixed dead area, sends an injection control instruction to the matrix type track-changing spray gun array according to the nitrogen oxide generation potential area and the mixed dead area, and sends an excitation mode switching instruction to the acoustic wave receiving and transmitting array.
2. The intelligent emission control and diagnostic system for a waste incineration power plant according to claim 1, wherein the central control unit, when reconstructing the three-dimensional temperature field distribution data, the three-dimensional dielectric constant field distribution data and the three-dimensional gas concentration field distribution data, performs the following operations: Based on the acoustic measurement vector, calculating the sound velocity value of a grid unit of a cross section of the hearth by using an algebraic reconstruction technology or a combined algebraic reconstruction technology, and calculating according to the thermodynamic dependence of the sound velocity and the absolute temperature to obtain two-dimensional temperature field distribution data; Based on the capacitance measurement vector, solving the inverse problem of the electrostatic field poisson equation by utilizing a pre-calculated sensitivity matrix and a linear back projection algorithm, and obtaining two-dimensional dielectric constant distribution data reflecting the volume fraction of the solid phase particles by means of solving; Based on the spectrum measurement data set, carrying out acousto-optic coupling correction by combining the two-dimensional temperature field distribution data, and then calculating by using a maximum likelihood expectation maximization algorithm to obtain two-dimensional gas concentration field distribution data; and carrying out space stacking and three-dimensional interpolation on the two-dimensional temperature field distribution data, the two-dimensional dielectric constant distribution data and the two-dimensional gas concentration field distribution data of each monitoring layer according to vertical height coordinates to generate the three-dimensional temperature field distribution data, the three-dimensional dielectric constant field distribution data and the three-dimensional gas concentration field distribution data.
3. An intelligent emission control and diagnostic system for a waste incineration power plant according to claim 2, characterised in that said acousto-optic modification in combination with said two-dimensional temperature field distribution data comprises in particular: discretizing and segmenting each light path of the laser grid monitoring unit according to the grid unit through which the light path passes; local temperature values corresponding to the discrete micro-element positions of the light path are searched out from the two-dimensional temperature field distribution data; correcting the laser spectral line intensity at the corresponding position by using the local temperature value, wherein a correction formula covers a distribution function term and an index term of the spectral line intensity along with the temperature change; and constructing a coefficient matrix containing temperature correction information based on the corrected spectral line intensity and absorbance measurement values in the spectrum measurement data set, and inverting the two-dimensional gas concentration field distribution data.
4. The intelligent emission control and diagnostic system for a waste incineration power plant according to claim 1, wherein the sound wave receiving and transmitting unit in the sound wave receiving and transmitting array is connected with a driving circuit comprising a mode change-over switch; the central control unit is configured to: in the measuring time slot, controlling the mode change-over switch to communicate a low-power transmitting branch with a high-sensitivity receiving branch, modulating a transmitting signal by utilizing a binary pseudo-random code sequence, and extracting the flying time based on a cross-correlation algorithm; And in the execution time slot, if the excitation mode switching instruction is received, controlling the mode switching switch to be communicated with a high-power driving branch, and driving the sound wave receiving and transmitting unit to transmit high-intensity sound waves modulated by single frequency or narrow band by using a programmable gain power amplifier.
5. The intelligent emission control and diagnostic system for a waste incineration power plant according to claim 1, characterised in that the central control unit, upon identifying the nitrogen oxide generation potential zone, performs in particular the following operations: Establishing a unified three-dimensional Cartesian coordinate system, and dividing the internal space of the hearth into unit voxels; Calculating dielectric constant spatial gradient modulus values of the three-dimensional dielectric constant field distribution data at each voxel position by using a center difference method; Judging whether each voxel simultaneously meets the following conditions that the temperature value of the voxel is larger than a preset high-temperature threshold value, and the dielectric constant spatial gradient modulus value of the voxel is larger than a preset dielectric constant gradient threshold value; And marking the voxel set which simultaneously meets the conditions as the nitrogen oxide generation potential area, and calculating the space centroid coordinates of the area by using a weighted centroid method.
6. The intelligent emission control and diagnosis system for a waste incineration power plant according to claim 1, wherein the central control unit traverses the three-dimensional gas concentration field distribution data when identifying the mixed dead zone, judges whether each voxel simultaneously satisfies the following conditions that the ammonia concentration of the voxel is greater than a preset ammonia escape threshold value and the nitrogen oxide concentration of the voxel is greater than a preset emission threshold value, marks the voxel simultaneously satisfying the above conditions as a mixed dead zone candidate point, identifies a connected region with the largest volume as the mixed dead zone by adopting a connected region marking algorithm, and calculates the geometric center coordinates of the region.
7. The intelligent emission control and diagnostic system for a waste incineration power plant according to claim 5, wherein the central control unit sends injection control instructions to the matrix-type variable trajectory spray gun array, comprising: Optimizing a spray gun with the nearest Euclidean distance from the space centroid coordinate of the nitrogen oxide generation potential zone from the matrix type track-changing spray gun array; Establishing a local coordinate system with a nozzle of the spray gun as an origin, and calculating a horizontal deflection angle and a vertical pitch angle of the spray gun according to the space centroid coordinate by using an inverse kinematics algorithm; Calculating a target injection flow of the reducing agent based on a stoichiometric ratio model according to an average temperature value in the nitrogen oxide generation potential zone; And sending the horizontal deflection angle, the vertical pitch angle and the target injection flow to a double-shaft adjusting mechanism and a flow adjusting valve of the spray gun as the injection control instructions.
8. The intelligent emission control and diagnostic system for a waste incineration power plant according to claim 6, wherein the central control unit sends excitation mode switching instructions to the acoustic transceiver array, and specifically comprises: Calculating the phase delay amount of each sound wave receiving and transmitting unit in the sound wave receiving and transmitting array by utilizing a wave beam synthesis algorithm based on the geometric center coordinates of the mixed dead zone; the calculation of the phase delay amount meets the requirement that the wave fronts of the sound waves emitted by the sound wave receiving and transmitting units are overlapped in phase at the geometric center coordinates; And controlling the sound wave receiving and transmitting array to emit high-intensity sound waves according to the phase delay amount, forming an acoustic energy density focusing area in the mixing dead area, and inducing secondary turbulence vortex by utilizing acoustic flow driving force generated by acoustic energy density gradient.
9. An intelligent emission control and diagnostic system for a waste incineration power plant according to claim 1, characterised in that the capacitive tomography sensor array comprises a plurality of pairs of electrode units; The central control unit controls the multichannel data acquisition card to sequentially gate a pair of electrode units to serve as excitation electrodes and measurement electrodes respectively through an analog switch matrix in the measurement time slot; applying an alternating current sinusoidal excitation signal to the excitation electrode and measuring the mutual capacitance value of the measurement electrode; And carrying out differential processing on the measured mutual capacitance value and a pre-stored reference capacitance value in an idle state to generate the normalized capacitance measurement vector.
10. An intelligent emission control and diagnostic system for a waste incineration power plant according to claim 1, characterised in that the laser grid monitoring unit comprises a laser transmitter group and a laser receiver group; The tunable semiconductor lasers in the laser emitter group are configured to periodically scan the output wavelength in a wave band containing characteristic absorption peaks of the gas to be detected; The laser receiver group is provided with a lock-in amplifier which is used for extracting a second harmonic signal in a received light intensity signal and transmitting the second harmonic signal as the spectrum measurement data set to the central control unit.

Description

Intelligent emission control and diagnosis system for waste incineration power plant Technical Field The invention relates to the technical field of garbage incineration power generation and environmental protection control, in particular to an intelligent emission control and diagnosis system for a garbage incineration power plant. Background The garbage incineration power generation is used as a main means for treating urban solid wastes, and the combustion process has high complexity and unsteady state characteristics. Because of the huge fluctuation of the components, the water content and the heat value of the garbage entering the furnace, the temperature field, the flow field and the chemical component concentration field inside the hearth show three-dimensional distribution characteristics which are extremely uneven and rapidly changed along with time. In order to meet the increasingly strict emission standard of nitrogen oxides, the selective non-catalytic reduction technology is widely applied to the flue gas denitration process of the waste incineration power plant. The core of the technology is that a reducing agent (such as ammonia water or urea solution) is sprayed into a specific temperature window area of a hearth to cause the reducing agent to react with nitrogen oxides in flue gas in a reducing way. However, existing control systems still have significant technical limitations in terms of monitoring accuracy and injection execution. In the aspect of monitoring, the traditional hearth temperature monitoring mainly relies on wall thermocouples, which can only provide single-point temperatures near a heating surface and cannot truly reflect the temperature distribution of the hearth section and a core area. Although tunable semiconductor laser absorption spectroscopy techniques have been introduced for gas concentration monitoring, their measurement principle is based on integrated absorption characteristics over the line-of-sight path, and the line-of-sight intensity of gas molecules has a strong dependence on temperature. In the environment of the garbage incinerator with a great temperature gradient, the prior art often adopts the path average temperature or the set temperature for inversion, ignores the influence of the temperature non-uniformity on the light path on the light absorption rate, and leads to larger deviation between the concentration measured value and the true value of the ammonia gas and the nitrogen oxide. In terms of control execution, existing reductant injection strategies are typically feedback adjusted based on the emission index of the outlet cross section or a rough temperature partition due to lack of high resolution three-dimensional physical field data inside the furnace. The control mode essentially belongs to a hysteresis and uniform adjusting means, and can not accurately identify and track a local high-temperature core area or a high-concentration nitrogen oxide generation area which is randomly generated in a hearth. In addition, the arrangement and injection trajectory of the lance are generally fixed, and it is difficult to adapt to the situation of offset of the combustion center, so that the excessive injection of the reducing agent in a partial area causes ammonia escape, and insufficient coverage in another partial area causes low denitration efficiency. Meanwhile, in certain low flow rate or laminar flow areas in the hearth, the mixing of the reducing agent and the flue gas is limited by mass transfer resistance to form a reaction dead zone, and the existing technical means lack an effective non-invasive interference mechanism to break such a partially poorly mixed state. The problems above together lead to situations of large consumption of reducing agent, difficult control of ammonia escape and severe fluctuation of emission indexes in the existing system. Therefore, the invention provides an intelligent emission control and diagnosis system for a waste incineration power plant, which aims to solve the defects in the prior art. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an intelligent emission control and diagnosis system for a waste incineration power plant, which solves the problems provided in the background art. The first aspect of the invention provides an intelligent emission control and diagnostic system for a waste incineration power plant. The system comprises an acoustic wave receiving and transmitting array, a capacitance tomography sensor array, a laser grid monitoring unit, a matrix type track-changing spray gun array and a central control unit. The central control unit is respectively connected with the arrays and the units in a communication way. At the control logic level, the central control unit is configured with time division multiplexing logic to divide the working period of the system into measurement time slots and execution time slots which are not overlapped with each other. The a