CN-121976869-A - Control method, device and equipment of vehicle-mounted urea injection system

CN121976869ACN 121976869 ACN121976869 ACN 121976869ACN-121976869-A

Abstract

The application discloses a control method, a device and equipment of a vehicle-mounted urea injection system, and relates to the field of denitration treatment of engine tail gas. The method comprises the steps of receiving real-time working condition data of an engine and a pre-stored urea injection MAP, inquiring the urea injection MAP according to exhaust temperature and nitrogen oxide concentration, determining a basic urea injection quantity, dynamically correcting the basic urea injection quantity according to an engine load factor and exhaust flow to obtain a target urea injection quantity, obtaining a peristaltic pump for controlling a target vehicle to operate according to a real-time pressure value, determining a PWM control signal based on the target urea injection quantity and the real-time pressure value, and driving a metering electromagnetic valve and an atomization electromagnetic valve of the target vehicle to perform urea aqueous solution atomization injection according to the PWM control signal. The application can ensure the accurate and customized adjustment of key parameters such as timing sequence, precision, pre-injection logic, flushing logic and the like of urea injection, and effectively solves the inherent defects of insufficient control right, insufficient flexibility and the like in the prior art.

Inventors

WENG LINGYUN
HUANG GAOFENG
SUN JIN
Ma Xinman

Assignees

武汉安立杰工程技术有限公司

Dates

Publication Date: 20260505
Application Date: 20260225

Claims (10)

1. The control method of the vehicle-mounted urea injection system is characterized by comprising the following steps of: Receiving real-time working condition data of an engine of a target vehicle and a pre-stored urea injection MAP, wherein the real-time working condition data of the engine comprises exhaust temperature, nitrogen oxide concentration, engine load rate and exhaust flow; Inquiring the urea injection MAP according to the exhaust temperature and the nitrogen oxide concentration, determining a basic urea injection quantity, and dynamically correcting the basic urea injection quantity according to the engine load factor and the exhaust flow to obtain a target urea injection quantity; acquiring a real-time pressure value of a urea pipeline, and controlling a peristaltic pump of the target vehicle to run according to the real-time pressure value; And determining a PWM control signal based on the target urea injection quantity and the real-time pressure value, and driving a metering electromagnetic valve and an atomization electromagnetic valve of the target vehicle to perform urea aqueous solution atomization injection according to the PWM control signal.
2. The method of claim 1, wherein the receiving engine real-time operating condition data of the target vehicle comprises: receiving real-time working condition data of an engine sent by a previous controller through an industrial communication protocol, wherein the previous controller is an upper computer controller or an engine controller; and carrying out validity verification on the real-time working condition data of the engine, and if the validity verification result of the real-time working condition data of the engine is invalid, adopting the history working condition data of the engine as the real-time working condition data of the engine controlled at the time.
3. The method of claim 1, wherein dynamically correcting the base urea injection amount based on the engine load factor and the exhaust flow rate to obtain a target urea injection amount comprises: Determining a load correction coefficient according to the engine load factor, and determining a flow correction coefficient based on the deviation of the exhaust flow rate from a reference flow rate; and multiplying the basic urea injection quantity by the load correction coefficient and the flow correction coefficient to obtain the target urea injection quantity.
4. The method of claim 1, wherein said controlling peristaltic pump operation of the target vehicle in accordance with the real-time pressure value comprises: comparing the real-time pressure value with a preset pressure value range, and if the real-time pressure value is lower than the minimum value of the range of the real-time pressure value and the preset pressure value, increasing the rotating speed of the peristaltic pump; If the real-time pressure value is higher than the maximum value of the preset pressure value range, reducing the rotating speed of the peristaltic pump; and if the time length of the real-time pressure value which is not in the preset pressure value range reaches the preset time length, switching to the standby peristaltic pump.
5. The method of claim 1, wherein the determining a PWM control signal based on the target urea injection amount and the real-time pressure value comprises: Obtaining a target pressure value of the urea pipeline and a preset mapping relation table, wherein the preset mapping relation table comprises mapping relations between each equivalent flow and each basic duty ratio; According to the target urea injection quantity and the real-time pressure value, calculating to obtain an equivalent flow under a standard pressure difference, and determining a basic duty ratio through a preset mapping relation table based on the equivalent flow; and adjusting the basic duty ratio according to the target pressure value and the real-time pressure value to obtain a target duty ratio, and generating the PWM control signal based on the target duty ratio.
6. The method of claim 5, wherein calculating an equivalent flow rate at a standard differential pressure based on the target urea injection amount and the real-time pressure value comprises: Acquiring an exhaust pipe pressure value, and determining an actual pressure difference value between the exhaust pipe pressure value and the real-time pressure value; And determining a standard pressure difference value between the target pressure value and the real-time pressure value, and calculating to obtain the equivalent flow under the standard pressure difference according to the target urea injection quantity, the actual pressure difference value and the standard pressure difference value.
7. The method of claim 5, wherein said adjusting the base duty cycle based on the target pressure value and the real-time pressure value results in a target duty cycle, comprising: Determining a deviation value between the target pressure value and the real-time pressure value, and acquiring a preset pressure compensation coefficient; and determining a duty cycle trimming amount according to the deviation value and the pressure compensation coefficient, and carrying out addition processing on the duty cycle trimming amount and the basic duty cycle to obtain the target duty cycle.
8. The method according to claim 1, wherein the method further comprises: closing the metering solenoid valve and the atomizing solenoid valve, and opening the purging solenoid valve; Controlling the peristaltic pump to reversely run for a set time, and pumping back the residual urea in the urea pipeline to a urea tank; and continuously introducing compressed air to purge the urea pipeline, and closing a target valve after the purging is completed and entering a standby state, wherein the target valve comprises a metering electromagnetic valve, an atomizing electromagnetic valve and a purging electromagnetic valve.
9. A control device for a vehicle-mounted urea injection system, comprising: The data acquisition module is used for receiving real-time working condition data of an engine of the target vehicle and a pre-stored urea injection MAP, wherein the real-time working condition data of the engine comprises exhaust temperature, nitrogen oxide concentration, engine load rate and exhaust flow; the injection quantity determining module is used for inquiring the urea injection MAP according to the exhaust temperature and the nitrogen oxide concentration, determining a basic urea injection quantity, and dynamically correcting the basic urea injection quantity according to the engine load rate and the exhaust flow to obtain a target urea injection quantity; The command control module is used for acquiring a real-time pressure value of the urea pipeline and controlling a peristaltic pump of the target vehicle to run according to the real-time pressure value; And the urea injection module is used for determining a PWM control signal based on the target urea injection quantity and the real-time pressure value, and driving a metering electromagnetic valve and an atomization electromagnetic valve of the target vehicle to perform urea aqueous solution atomization injection according to the PWM control signal.
10. An electronic device comprising a processor and a memory: The memory is configured to store a computer program which, when executed by the processor, causes the processor to perform the method of any of claims 1-8.

Description

Control method, device and equipment of vehicle-mounted urea injection system Technical Field The embodiment of the application relates to the field of denitration treatment of engine tail gas, in particular to a control method, a device and equipment of a vehicle-mounted urea injection system. Background Currently, in the field of purification of nitrogen oxides (NOx) in the exhaust gas of diesel engines, selective Catalytic Reduction (SCR) technology is the mainstream solution, the core of which consists in precisely injecting an aqueous urea solution into the exhaust pipe. The prior art generally adopts a highly integrated vehicle-mounted urea injection system, which is generally composed of a urea pump, a nozzle, a DCU (diesel engine control unit or special injection control unit) and various sensors. According to the disclosed industry practice and common knowledge in the art, the existing closest technical scheme is that a main engine ECU sends a simple instruction, such as a target urea injection quantity, to a special DCU through a specific communication network, and the DCU then drives a urea pump and a nozzle to complete injection according to control logic and a special communication message protocol solidified in the DCU. However, although the existing vehicle-mounted urea injection system is mature in application on a standard vehicle type, the existing system encapsulates the core control logic inside a special DCU, and interacts through preset and non-public special communication messages, so that the precise and customized adjustment of key parameters such as urea injection time sequence, precision, pre-injection logic, flushing logic and the like cannot be performed at the moment, and the inherent defects of insufficient control right and flexibility and the like exist, so that the popularization and application of the system in engineering projects requiring high customization and diversification are restricted. Disclosure of Invention The object of the present application is to solve at least one of the technical drawbacks mentioned above. In one aspect, an embodiment of the present application provides a method for controlling a vehicle-mounted urea injection system, where the method includes: receiving real-time working condition data of an engine of a target vehicle and a pre-stored urea injection MAP, wherein the real-time working condition data of the engine comprises exhaust temperature, nitrogen oxide concentration, engine load rate and exhaust flow; Inquiring a urea injection MAP according to the exhaust temperature and the concentration of nitrogen oxides, determining a basic urea injection quantity, and dynamically correcting the basic urea injection quantity according to the engine load rate and the exhaust flow rate to obtain a target urea injection quantity; acquiring a real-time pressure value of a urea pipeline, and controlling a peristaltic pump of a target vehicle to operate according to the real-time pressure value; and determining a PWM control signal based on the target urea injection quantity and the real-time pressure value, and driving a metering electromagnetic valve and an atomization electromagnetic valve of the target vehicle to perform urea aqueous solution atomization injection according to the PWM control signal. Optionally, receiving the engine real-time operating condition data of the target vehicle includes: Receiving real-time working condition data of an engine sent by a previous controller through an industrial communication protocol, wherein the previous controller is an upper computer controller or an engine controller; And carrying out validity verification on the real-time working condition data of the engine, and if the validity verification result of the real-time working condition data of the engine is invalid, adopting the history working condition data of the engine as the real-time working condition data of the engine controlled at the time. Optionally, dynamically correcting the basic urea injection quantity according to the engine load rate and the exhaust flow to obtain the target urea injection quantity, including: determining a load correction coefficient according to the engine load factor, and determining a flow correction coefficient based on the deviation of the exhaust flow and the reference flow; And multiplying the basic urea injection quantity by a load correction coefficient and a flow correction coefficient to obtain a target urea injection quantity. Optionally, controlling operation of the peristaltic pump of the target vehicle according to the real-time pressure value includes: Comparing the real-time pressure value with a preset pressure value range, and if the real-time pressure value is lower than the minimum value of the preset pressure value range, increasing the rotating speed of the peristaltic pump; If the real-time pressure value is higher than the maximum value of the preset pressure value range, the rotating speed o