Engine exhaust gas recirculation device and control method thereof

Abstract

The invention discloses an engine exhaust gas recirculation device and a control method thereof. The device comprises a first pipeline connected with an exhaust pipe, a second pipeline and a third pipeline connected with an intake pipe; There is an EGR valve and an EGR cooler; the first pipeline is connected to the exhaust pipe on the front side of the catalytic converter; it also includes a fourth pipeline connecting the exhaust pipe on the rear side of the catalytic converter to the second pipeline; the second pipeline A branch is connected to the three pipelines at the gas outlet, and a compressor is provided on the branch; it also includes a first and a second switching valve, the first switching valve can conduct in the first and second pipelines and the fourth and second The position where the two pipelines are cut off, and the position where the first and second pipelines are cut off and the fourth and second pipelines are connected; the second switching valve can be connected to the second and third pipelines and the third Switch between the position where the pipeline and the branch are cut off, and the position where the second and third pipelines are cut off and the third pipeline is connected to the branch. This device can realize the maximum benefit of EGR.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to an engine exhaust gas recirculation device and a control method thereof. Background technique [0002] Exhaust Gas Recirculation (EGR) technology sends part of the exhaust gas discharged from the engine back to the intake manifold, and re-enters the cylinder together with the fresh mixed gas to increase the specific heat capacity of the mixed gas in the combustion chamber and reduce the maximum Combustion temperature can reduce the amount of nitrogen oxides in the exhaust gas, and it can also improve part-load fuel consumption, so it has been used more and more. [0003] The current EGR technology can be divided into internal EGR and external EGR. Among them, the EGR rate that can be achieved by internal EGR is very limited, and the external EGR technology mainly relies on the pressure difference between the exhaust and intake system to drive the exhaust gas of the engine to retu...

AI Technical Summary

Problems solved by technology

[0003] The current EGR technology can be divided into internal EGR and external EGR. Among them, the EGR rate that can be achieved by internal EGR is very limited, and the external EGR technology mainly relies on the pressure difference between the exhaust and intake system to drive the exhaust gas of the engine to return to the intake system. , so that the EGR rate is affected by the operating conditions of the engine, it is difficult to realize the maximum utilization of the EGR rate in each operating condition

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