Single-cylinder diesel engine egr device and control method based on high-pressure air source

Abstract

The invention aims at providing a high-pressure gas source based single-cylinder diesel engine EGR device and a control method. The high-pressure gas source based single-cylinder diesel engine EGR device comprises a single-cylinder diesel engine, a turbocharger, a three-way intake valve and a three-way exhaust valve; the three-way intake valve comprises a gas inlet, a first gas outlet and a second gas outlet; the gas inlet is communicated with a high-pressure external gas source through a high-pressure external gas source intake valve; a first gas intake branch is arranged between the first gas outlet and the single-cylinder diesel engine, while a second gas intake branch is arranged between the second gas outlet and a turbine of the turbocharger; the three-way exhaust valve comprises an exhaust port, a first waste gas port and a second waste gas port; the exhaust port is connected with the single-cylinder diesel engine; the first waste gas port is communicated with the atmosphere through a first waste gas branch; a second waste gas branch is arranged between the second waste gas port and a gas compressor of the turbocharger; the gas compressor is connected with the first gas intake branch through an EGR pipeline; and a one-way valve and an electromagnetic control valve are orderly arranged on the EGR pipeline. The high-pressure gas source based single-cylinder diesel engine EGR device solves the problems of failure in backflow due to over-high intake pressure and too low exhaust pressure, and the like.

Description

technical field [0001] The invention relates to a diesel engine, in particular to an EGR device for a diesel engine and a control method thereof. Background technique [0002] The so-called exhaust gas recirculation (EGR) is a process in which a part of the exhaust gas is introduced into the intake pipe, mixed with fresh air, and then enters the cylinder to participate in combustion again. With the stricter NOX emission regulations of marine diesel engines, EGR has become one of the most effective means to reduce NOX emissions. How to implement EGR is the key to EGR technology. At present, there are two main implementation methods for supercharged diesel engines: low-pressure EGR and high-pressure EGR. The difference between the two is that low-pressure EGR introduces the exhaust gas before the turbine to the compressor inlet, while high-pressure EGR introduces the exhaust gas before the turbine to the compressor outlet. Because low-pressure EGR is easy to cause leakage of...

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Problems solved by technology

[0004] The object of the present invention is to provide a single-cylinder diesel engine EGR device and control method based on a high-pressure air source that overcomes the problems of high intake pressure and low exhaust pressure that cannot cause backflow.

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