EGR (Exhaust Gas Recirculation) mixer for marine diesel engine

Abstract

The invention provides an EGR (Exhaust Gas Recirculation) mixer for a marine diesel engine. The EGR mixer comprises a mixer housing, an EGR gas introducing device and a discharging hole; the EGR gas inducting device is arranged on the mixer housing; the discharging hole formed in the lowest part of the mixer housing is used for discharging acidic liquid that is separated out during mixing high-temperature EGR gas with inter-cooled fresh air. According to the EGR mixer for the marine diesel engine, the discharging hole is formed in the lowest part of the mixer housing, which effectively overcomes the problem of discharging acidic liquid and prevents acidic liquid from entering the cylinder, and thus the EGR mixer is applicable to the marine diesel engine; an outlet end of an EGR gas introducing pipe is closed, a gas spray hole that is axially vertical to the fresh air flowing direction is formed in the EGR gas introducing pipe, and thereby, the EGR gas is vertical to the fresh air in flowing direction to generate a local turbulence which is beneficial for full mixing of gas; the EGR mixer for the marine diesel engine is simple in structure, and can be integrally dismounted, so that parts of the mixer can be conveniently replaced and temporarily dismounted for examination.

Description

technical field [0001] The invention relates to the field of marine diesel engines, in particular to an exhaust gas recirculation system mixer for marine diesel engines. Background technique [0002] Exhaust Gas Recirculation (Exhaust Gas Recirculation) system, referred to as EGR, is a technology that sends a small part of the exhaust gas generated by the engine back to the cylinder for re-combustion. Specifically, the exhaust gas from the engine is mixed with fresh air in the EGR mixer and then enters cylinder. [0003] The EGR mixer is an important part of the EGR system. Its function is to fully mix the EGR gas (exhaust gas introduced into the intake air of the diesel engine) and the fresh air after the supercharged intercooler, so that the intake air of the diesel engine at the outlet of the EGR mixer is spaced The composition is uniform. [0004] At present, there are many structural types of the EGR mixer, for example: Chinese patent CN103397956A proposes to set a sp...

AI Technical Summary

Problems solved by technology

[0007] The invention provides a mixer for marine diesel engine EGR system. On the one hand, by setting a release hole at the lowest part of the mixer shell, it effectively solves the acidity that is precipitated when the high-temperature EGR gas is mixed with the fresh air after supercharging and intercooling. The problem of liquid release ensures that the acidic liquid does not enter the cylinder, effectively avoiding the corrosion of the engine parts by the acidic liquid and affecting the reliability of the engine, making the EGR mixer suitable for marine diesel engines; on the other hand, the gas outflow end of the EGR gas introduction pipe is closed , on the EGR gas introduction pipe, a plurality of gas injection holes whose axial direction is perpendicular to the flow direction of the fresh air is arranged, so that the EGR gas is perpendicular to the flow direction of the fresh air, thus forming a local turbulence, which is conducive to the full mixing of the gas

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