EGR (Exhaust Gas Recirculation) valve control system and control method thereof

Abstract

The invention relates to an EGR (Exhaust Gas Recirculation) valve control system and a control method thereof. The system comprises a controller ECU, an EGR system, a rotating speed sensor, an atmospheric temperature sensor, an atmospheric pressure sensor, a cooling liquid temperature sensor, a TMAP sensor, a Venturi flow meter differential pressure sensor and an EGR valve downstream temperature sensor. The EGR system comprises an EGR valve, an EGR intercooler and a Venturi tube; the EGR valve is connected with an exhaust pipe of the engine, and the other end of the EGR valve is connected with the EGR intercooler; the other end of the EGR intercooler is connected with the Venturi tube; the Venturi tube is connected with an air inlet pipe of the engine; and the rotating speed sensor, the atmospheric temperature sensor, the atmospheric pressure sensor, the cooling liquid temperature sensor, the TMAP sensor, the Venturi flow meter differential pressure sensor and the EGR valve downstream temperature sensor are all connected with the controller ECU. According to the EGR valve control system and the control method thereof provided by the invention, on the basis of the closed-loop control principle, PID control can be conducted on the waste gas flow according to the actual operation working condition of the engine, the opening degree of the EGR valve is adjusted in real time, emission of NOX can be effectively controlled, and meanwhile, fuel economy is improved.

Description

Technical field [0001] The present invention belongs to the technical field of diesel engine control, and is specifically an EGR valve control system and a control method thereof. Background technique [0002] With the continued improvement of environmental awareness around the world, vehicle emission regulations are increasingly strict. my country will implement national 6 emissions regulations in 2020, which is expected to implement lower emission control standards in 2025. In order to meet environmental requirements, some of them are gradually applied to diesel engines such as intravation control technology, post-treatment techniques, low temperature combustion techniques. Exhaust gas recirculation (EGR, Exhaust Gas Recirculation) As a kind of intake control technology, it is a valid measure to reduce Diesel Engine NOx emissions. [0003] The working principle of the EGR system is to control the amount of exhaust gas into the EGR airway, so that a certain amount of exhaust gas...

AI Technical Summary

Problems solved by technology

[0004] However, as the EGR rate increases, the residual exhaust gas in the cylinder increases, the combustion phase is delayed, and the reaction speed slows down, resulting in poor combustion and poor fuel economy; at the same time, the pumping loss caused by the EGR rate will also increase fuel consumption.

[0005] There are many error factors in the existing closed-loop air flow, and the error when the model calculates the total intake air volume will be added to the fresh air volume, thereby reducing the accuracy of EGR control, which is not conducive to the stability of emissions, and cannot fundamentally solve the problem of EGR delay and Precise control of EGR amount, etc.

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