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 a gas inlet pipe. An EGR valve and an EGR cooler are arranged on the second pipeline. The first pipeline is connected with the position, on the front side of a catalyst, of the exhaust pipe. A fourth pipeline connected with the position, on the rear side of the catalyst, of the exhaust pipe and the second pipeline is further included. A branch is branched from the gas outlet end of the second pipeline to be connected with the third pipeline, and a gas compressor is arranged on the branch. A first switching valve and a second switching valve are further included, the firstswitching valve can be switched between the position where the first pipeline and the second pipeline are connected and the fourth pipeline and the second pipeline are cut off and the position where the first pipeline and the second pipeline are cut off and the fourth pipeline and the second pipeline are connected. The second switching valve can be switched between the position where the second pipeline and the third pipeline are connected and the third pipeline and the branch are cut off and the position where the second pipeline and the third pipeline are cut off and the third pipeline and the branch are connected. The device can achieve EGR revenue maximization.

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

Images