A diesel engine post-processing scr control device and control method

Abstract

The invention provides a diesel engine aftertreatment SCR control device and method. The control device comprises an SCR controller, an engine, an exhaust pipe, a catalyst device, a metering pump, an NO<x> sensor, a urea tank, an upstream temperature sensor, a downstream temperature sensor, a nozzle, a cooling water control electromagnetic valve, a water supply pipeline, a heating pipeline, a urea solution pipeline, an instrument and an OBD diagnosis device. According to the diesel engine aftertreatment SCR control device, the system reliability, safety and the compatibility can be improved, and the low energy consumption function is achieved; the system signal collection precision and stability are improved, and therefore the urea injection amount control precision is improved; the system power output reliability is improved; the device can be compatible with different commercial vehicle instrument connectors, analog and digital instrument drive is achieved, the efficiency of taking NO<x> out of engine exhaust reaches 85%, the vehicle diesel engine reaches the national V emission standard, and the OBD function is achieved.

Description

technical field [0001] The invention belongs to the field of diesel engine control, and in particular relates to a diesel engine post-processing SCR control device and a control method. Background technique [0002] With the development of the automobile industry, my country's energy and motor vehicle environmental protection issues have become very serious, people's health has been greatly threatened, and my country has also issued increasingly stringent emission regulations. Compared with gasoline vehicles, diesel engines have lower fuel consumption and correspondingly reduce air pollution, which is more conducive to environmental protection. Now the carbon dioxide emitted by the new diesel engine is 20% lower than that of the gasoline engine, and the emitted CO and HC are also less. However, the NO of the diesel engine X Emissions and particulate emissions are more serious than those of gasoline engines, which have also become obstacles to its development, especially fo...

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Problems solved by technology

[0007] In the prior art, there are many studies on the SCR control system. There are many defects in the existing technical solutions: there is no electromagnetic compatibility design, the SCR control device is a control system for commercial vehicles, and the electromagnetic interference on commercial vehicles is relatively serious. The SCR control device Reliability declines; there is no power management system, no low power consumption design, no energy saving function; the existing system only has one CAN interface, so it is difficult to be compatible with engines, metering pumps, instruments, NO X Compatibility between different baud rates and data protocols of sensors and OBD devices, and because the engine CAN interface is incorporated into multiple CAN devices, the data capacity increases sharply, which poses a security risk to the CAN network data exchange of the vehicle engine itself; The interface of the automobile instrument does not adopt redundant design. The functional structure of the automobile instrument is different, and the SCR control device and the interface of the instrument are different.

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