Low-speed two-stroke gas fuel engine cylinder

Abstract

The invention relates to a low-speed two-stroke gas fuel engine cylinder. The low-speed two-stroke gas fuel engine cylinder comprises a cylinder body, a cylinder cover, an exhaust passage, an exhaust valve, air injection valves, scavenging ports and a piston; the cylinder cover is arranged at the top of the cylinder body, the exhaust passage is in communication with the top of the cylinder cover, one end of the exhaust valve is in communication with the top of the cylinder body, and the other end of the exhaust valve is in communication with the exhaust passage; the scavenging ports are circumferentially and evenly distributed on the outer side of the bottom area of the cylinder body, the piston is arranged on the inner side of the bottom of the cylinder body, the air injection valves are arranged on the cylinder walls on the two sides of the lower portion of the cylinder body, and the piston is always positioned below the air injection valves in the injection duration; and the side slip angle gamma of the air injection valves ranges from 10 degrees to 30 degrees, and the lower slip angle alpha of the air injection valves ranges from 10 degrees to 30 degrees. According to the low-speed two-stroke gas fuel engine cylinder, on the premise that fuel does not escape from the exhaust valve, the uniformity of mixed gas in the cylinder reaches the best, so that the phenomena of abnormal combustion and the like of a low-speed two-stroke gas fuel engine can be effectively avoided, and efficient and stable lean combustion is achieved.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to a low-speed two-stroke gas fuel engine cylinder. Background technique [0002] Low-speed two-stroke gaseous fuel engines using premixed combustion mode can directly meet the requirements of the third-stage emission regulations of the International Maritime Organization (IMO Tier 3), but the engine with this combustion mode will face pre-ignition and knocking under high load conditions and other abnormal combustion problems. The marine low-speed two-stroke gas fuel engine has a large bore, super-long stroke structure and extremely low speed operation characteristics, which makes the tendency and frequency of abnormal combustion higher, and the threat is greater. Because the "abnormal combustion" problem is extremely difficult to solve, it is difficult for a low-speed two-stroke gas fuel engine to achieve efficient and stable combustion. In order to avoid flashback, low-speed two...

AI Technical Summary

Problems solved by technology

After adopting in-cylinder direct injection, the threat of flashback is eliminated, but due to the short mixing time of fuel and air, residual high-temperature hot spots in the cylinder and inhomogeneity of the mixture in the cylinder will still cause "pre-ignition" and "knocking"

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