Waste gas recirculating system, motor vehicle, and control method of waste gas recirculating system

Abstract

The invention provides a waste gas recirculating system, a motor vehicle, and a control method of the waste gas recirculating system. The system comprises an EGR before-cooling pipeline, an EGR cooler, an EGR after-cooling pipeline, an engine, an air intake main pipe, an exhaust main pipe and an EGR butterfly valve, wherein at least one exhaust manifold of the engine is connected with the exhaust main pipe and the EGR before-cooling pipeline through the EGR butterfly valve. When the EGR butterfly valve is in a first state, at least one exhaust manifold is communicated with the EGR before-cooling pipeline; waste gas discharged by the at least one exhaust manifold enters the EGR cooler by the EGR before-cooling pipeline for cooling; the cooled waste gas is input into the air intake main pipe by the EGR after-cooling pipeline, and is led into the engine by the air intake main pipe. When the EGR butterfly valve is in a second state, at least one exhaust manifold is communicated with the exhaust main pipe, and the waste gas discharged by the at least one exhaust manifold is exhausted by the exhaust main pipe. The system can enhance the EGR rate and reduce the conditions of pumping loss and air inflow reduction of the engine.

Description

technical field [0001] The invention relates to the technical field of engines, more specifically, to an exhaust gas recirculation system, a motor vehicle and a control method for the exhaust gas recirculation system. Background technique [0002] The exhaust gas recirculation system (EGR system) is one of the effective means for the engine to reduce NOx emissions; the EGR system introduces part of the engine exhaust gas to the engine intake pipe, and the exhaust gas is reintroduced into the cylinder to participate in combustion, which can reduce the oxygen concentration in the cylinder and the maximum combustion. temperature to achieve the effect of reducing NOx. [0003] In the EGR system, the ratio of the exhaust gas entering the engine intake pipe to the total gas mass of the cylinder is the EGR rate. In order to make the EGR system further reduce NOx emissions, it is necessary to increase the EGR rate of the EGR system; the current way to increase the EGR rate is mainly...

AI Technical Summary

Problems solved by technology

[0005] In view of this, an embodiment of the present invention provides an exhaust gas recirculation system, a motor vehicle and a control method for the exhaust gas recirculation system, so as to solve the problem of increasing the pumping loss of the engine and reducing the engine's pumping loss in the existing methods of increasing the EGR rate. The amount of air intake leads to an increase in fuel consumption of the engine and an increase in particulate matter emissions

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