Exhaust valve structure of low-speed two-stroke marine diesel engine

Abstract

The invention discloses an exhaust valve structure for a low-speed two-stroke marine diesel engine. The scheme is as follows: the exhaust valve is provided with an exhaust flow passage, and the inlet of the exhaust passage is arranged on the bottom surface of the exhaust valve; the outlet is arranged on the sealing surface of the exhaust valve. The exhaust runners are arranged circumferentially along the central axis of the exhaust valve. The flow channel can choose a single-ring or double-ring structure, and the angle α between the centerline of the single-ring exhaust flow channel and the horizontal plane is 20° to 40°. The double-ring layout structure is divided into inner ring and outer ring, the inner ring flow path angle α is 20°-40°; the outer ring flow path angle α' is 30°-50°. The angle β between the centerlines of all exhaust runners and the centerline of the exhaust valve projected onto the horizontal plane is 10°-20°. By setting the exhaust flow channel between the bottom surface of the valve and the sealing surface, the residual exhaust gas accumulated in the exhaust gas accumulation area under the valve is effectively eliminated, and the scavenging efficiency can be obviously improved. Through the design of different structural angles of the exhaust flow channel, the flow resistance of the exhaust gas is minimized, and the working performance of the diesel engine is improved.

Description

technical field

[0001] The invention belongs to an engine structure, in particular to an exhaust valve structure of a low-speed two-stroke marine diesel engine. Background technique

[0002] The scavenging process of the marine low-speed two-stroke diesel engine covers the entire stage from the opening of the scavenging port (the end of the power stroke) to the closing of the exhaust valve (the end of the compression stroke), including providing fresh charge, discharging the exhaust gas in the cylinder, and providing an initial vortex to promote mixing. The efficient scavenging process can effectively improve the combustion performance of marine low-speed two-stroke diesel engines, thereby achieving the goals of increasing power, reducing fuel consumption and emissions, and enhancing engine reliability.

[0003] To improve the scavenging performance and scavenging efficiency of marine diesel engines, the main research is on the structure of scavenging ports, such as the opti...

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