CN-122014388-A - Automatic urea solution concentration adjusting and controlling system

CN122014388ACN 122014388 ACN122014388 ACN 122014388ACN-122014388-A

Abstract

The application discloses an automatic urea solution concentration adjusting and controlling system which comprises a multi-mode concentration detecting module, an intelligent control unit and a man-machine interaction and remote monitoring module, wherein the multi-mode concentration detecting module is used for detecting the concentration of urea solution in real time and comprises an ultrasonic phase difference detecting sub-module, an optical refraction detecting sub-module and a multi-mode information fusion and processing unit used for carrying out fusion treatment on detection results of the ultrasonic phase difference detecting sub-module and the optical refraction detecting sub-module, the dynamic matching executing module is used for accurately preparing urea solution according to control instructions, and the intelligent control unit is in signal connection with the multi-mode concentration detecting module and the dynamic matching executing module. According to the application, through the multi-mode concentration detection module, two detection technologies of ultrasonic phase difference and optical refractive index are fused, and a confidence evaluation and self-adaptive weighting fusion algorithm is combined, so that the measurement deviation of a single sensor under a complex working condition is effectively overcome, and the concentration detection with full range, no blurring and high reliability is realized.

Inventors

WANG GANG
LIN CHENGXIAN
Xiang Zhenhai
CONG SHUGUANG
ZHOU XIN

Assignees

华能国际电力股份有限公司大连电厂

Dates

Publication Date: 20260512
Application Date: 20260311

Claims (8)

1. An automatic urea solution concentration regulation and control system, comprising: The multi-mode concentration detection module is used for detecting the concentration of the urea solution in real time and comprises an ultrasonic phase difference detection submodule, an optical refraction detection submodule and a multi-mode information fusion and processing unit for carrying out fusion processing on detection results of the ultrasonic phase difference detection submodule and the optical refraction detection submodule; The dynamic proportioning execution module is used for accurately preparing urea solution according to the control instruction and comprises a bidirectional high-precision metering and supplying sub-module, an online instant dynamic mixing sub-module and a full-link intelligent crystallization-preventing heating sub-module, wherein the bidirectional high-precision metering and supplying sub-module is used for respectively controlling the supply of urea stock solution and deionized water; The intelligent control unit is in signal connection with the multi-mode concentration detection module and the dynamic proportioning execution module, and outputs control instructions to the dynamic proportioning execution module based on an ammonia storage model, multi-parameter fuzzy PID control and an online self-learning algorithm; and the man-machine interaction and remote monitoring module is used for providing a local operation interface and a remote monitoring function.
2. The urea solution concentration automatic regulation and control system of claim 1, wherein the multi-modal concentration detection module: The ultrasonic phase difference detection submodule adopts a multi-frequency ultrasonic phase difference detection technology, and solves the concentration of the urea solution by calculating the total phase difference of the cross period and combining the solution temperature; the optical refraction detection submodule detects the concentration of urea solution by adopting an optical refractive index sensor based on a critical angle principle; the multi-mode information fusion and processing unit is configured to evaluate the confidence coefficient of the detection results of the two sub-modules, perform self-adaptive weighted fusion according to the confidence coefficient and output a final concentration value.
3. The urea solution concentration automatic regulation and control system of claim 1, wherein the dynamic proportioning execution module: the bidirectional high-precision metering and supplying submodule comprises two high-precision metering pumps which are respectively used for conveying urea stock solution and deionized water, and a one-way valve is arranged at an inlet and an outlet of each pump; the online instant dynamic mixing sub-module is a static mixer and is arranged at the downstream of the junction point of two liquid flows; the full-link intelligent crystallization-preventing heating submodule comprises a device for carrying out zone heating and temperature control on a storage tank, a pipeline, a metering pump head and a static mixer.
4. The urea solution concentration automatic regulation and control system according to claim 1, characterized in that the intelligent control unit comprises: the self-adaptive set point planner dynamically outputs a target concentration value of the urea solution according to an SCR downstream NOx sensor signal, an SCR catalyst temperature, an engine working condition and an ammonia storage amount estimated in real time; A multi-parameter fuzzy PID real-time controller dynamically adjusts PID parameters or outputs control signals according to concentration deviation, deviation change rate, solution temperature and original NOx level of an engine so as to drive the metering pump; The on-line self-learner adopts a reinforcement learning algorithm, takes the working condition of the engine and the ammonia storage amount as states, takes the fine adjustment amount of the concentration set point and the PID parameter as actions, takes NOx conversion efficiency, ammonia leakage amount and concentration stability as rewards, and continuously optimizes the control strategy.
5. The urea solution concentration automatic regulation and control system of claim 1, wherein the human-machine interaction and remote monitoring module comprises: The local man-machine interaction sub-module is provided with an industrial touch screen and is used for displaying system states, parameter setting, data trend and alarm information, and is provided with a three-color state lamp, a buzzer and an emergency stop button; the remote monitoring and cloud platform sub-module is connected with the cloud platform through the gateway of the Internet of things to realize the functions of equipment asset management, global monitoring, data analysis and early warning, report generation and remote debugging; the multi-level alarm and notification management mechanism divides the alarm into a plurality of levels, and notifies responsible persons according to the levels through local acousto-optic, cloud platform recording and mobile phone pushing modes to form an alarm processing closed loop.
6. The urea solution concentration automatic regulation and control system of claim 3, wherein the dynamic proportioning execution module supports two modes of operation: the control unit calculates and controls the rotating speeds of the two metering pumps to accurately proportion according to the target concentration and the real-time detection concentration; And a flushing mode, wherein before the system is stopped, the deionized water pump is controlled to independently operate so as to flush the mixer and the downstream pipeline.
7. The urea solution concentration automatic regulation and control system of claim 4, wherein the adaptive set point planner is configured to execute at least one of the following rules: outputting target concentration higher than a standard value under the working conditions of low temperature and low ammonia storage; Under the working conditions of high load and high ammonia storage, outputting standard target concentration; under the working conditions of transient load reduction and ammonia storage oversaturation, outputting target concentration lower than a standard value; when ammonia leakage is detected, a zero concentration command is output and an alarm is triggered.
8. A machine readable storage medium storing a computer program which when executed by a processor implements the control logic of the intelligent control unit as claimed in claim 4.

Description

Automatic urea solution concentration adjusting and controlling system Technical Field The application belongs to the technical field of diesel engine tail gas aftertreatment, and particularly relates to an automatic urea solution concentration adjusting and controlling system. Background With increasing diesel exhaust emissions regulations, selective Catalytic Reduction (SCR) technology has become the dominant means of reducing nitrogen oxide (NOx) emissions. Urea solution (typically 32.5% AdBlue) acts as a reductant for SCR systems, and its concentration accuracy directly affects NOx conversion efficiency, ammonia slip, and system operational reliability. The existing urea solution supply system adopts a fixed concentration supply mode, is difficult to adapt to complex and variable operation conditions of an engine, is easy to cause unbalance of ammonia storage amount, causes incomplete conversion of NOx or excessive ammonia leakage, is easy to be interfered by temperature, bubbles and pollutants in a traditional concentration detection method (such as a single ultrasonic wave or refractive index method), is insufficient in measurement reliability, is easy to cause urea crystallization blockage in a low-temperature environment, is high in maintenance cost, and cannot dynamically optimize concentration setting and control parameters according to real-time working conditions due to lack of self-adaption and learning capability of a control system. Therefore, there is a need for an automatic urea solution concentration adjustment and control system that can achieve high precision, high reliability, and adaptive adjustment. Disclosure of Invention The application provides an automatic urea solution concentration adjusting and controlling system, which aims to solve the problems that the ammonia storage amount is unbalanced easily and the measurement reliability is insufficient in the prior art. In a first aspect, a urea solution concentration automatic regulation and control system, comprising: The multi-mode concentration detection module is used for detecting the concentration of the urea solution in real time and comprises an ultrasonic phase difference detection submodule, an optical refraction detection submodule and a multi-mode information fusion and processing unit for carrying out fusion processing on detection results of the ultrasonic phase difference detection submodule and the optical refraction detection submodule; The dynamic proportioning execution module is used for accurately preparing urea solution according to the control instruction and comprises a bidirectional high-precision metering and supplying sub-module, an online instant dynamic mixing sub-module and a full-link intelligent crystallization-preventing heating sub-module, wherein the bidirectional high-precision metering and supplying sub-module is used for respectively controlling the supply of urea stock solution and deionized water; The intelligent control unit is in signal connection with the multi-mode concentration detection module and the dynamic proportioning execution module, and outputs control instructions to the dynamic proportioning execution module based on an ammonia storage model, multi-parameter fuzzy PID control and an online self-learning algorithm; and the man-machine interaction and remote monitoring module is used for providing a local operation interface and a remote monitoring function. Optionally, in the multi-mode concentration detection module: The ultrasonic phase difference detection submodule adopts a multi-frequency ultrasonic phase difference detection technology, and solves the concentration of the urea solution by calculating the total phase difference of the cross period and combining the solution temperature; the optical refraction detection submodule detects the concentration of urea solution by adopting an optical refractive index sensor based on a critical angle principle; the multi-mode information fusion and processing unit is configured to evaluate the confidence coefficient of the detection results of the two sub-modules, perform self-adaptive weighted fusion according to the confidence coefficient and output a final concentration value. Optionally, in the dynamic proportioning execution module: the bidirectional high-precision metering and supplying submodule comprises two high-precision metering pumps which are respectively used for conveying urea stock solution and deionized water, and a one-way valve is arranged at an inlet and an outlet of each pump; the online instant dynamic mixing sub-module is a static mixer and is arranged at the downstream of the junction point of two liquid flows; the full-link intelligent crystallization-preventing heating submodule comprises a device for carrying out zone heating and temperature control on a storage tank, a pipeline, a metering pump head and a static mixer. Optionally, the intelligent control unit includes: the self-adaptive set point planner