Large-scale two-stroke turbocharging compression ignition internal combustion engine having waste gas cleaning system

Abstract

The invention discloses a crosshead type large-scale turbocharging two-stroke compression ignition internal combustion engine having a waste gas cleaning system. The crosshead type large-scale turbocharging two-stroke compression ignition internal combustion engine includes: a turbocharger having a waste gas drive turbine connected to a compressor for transmission boosting and scavenging; a plurality of cylinders which is connected to a scavenging receiving member and a waste gas receiving member; a selective catalytic reduction reactor which has an inlet connected to an outlet of the waste gas receiving member; an exhaust duct for connecting an outlet of the selective catalytic reduction reactor to an inlet of a turbine; a scavenging duct which connects an outlet of the compressor to an inlet of the scavenging receiving member via a scavenging cooler; an auxiliary blower which can assist the compressor during low load of an engine in the scavenging duct; a controllable bypass duct which extends to a position of the exhaust duct from a position of the scavenging duct; a electronic control bypass blower which is used for assisting flow of scavenge air from the scavenging duct to the exhaust duct; and an electronic control unit.

Description

technical field [0001] The present invention relates to a crosshead large turbocharged two-stroke compression ignition internal combustion engine, preferably an engine with an exhaust gas purification system, especially a crosshead large two-stroke diesel engine with a selective catalytic reduction reactor. Background technique [0002] Large crosshead two-stroke diesel engines are commonly used in the propulsion systems of large ships or as prime movers in power plants. The outbreak requirements have been and will become increasingly difficult to meet, especially for mononitrogen (NO x )grade. [0003] The use of selective catalytic reduction (SCR) reactors is known to assist in reducing NO in diesel engines x Distributed measures. A minimum temperature of about 300 to 350° C. for the exhaust gas entering the SCR converter is required for proper startup of the SCR reactor. [0004] However, due to the characteristics of two-stroke turbocharged engines, the exhaust gas t...

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Problems solved by technology

[0004] However, due to the characteristics of two-stroke turbocharged engines, the exhaust gas temperature at low engine loads (for example, below 40% of the maximum sustained rating of the relevant engine) is relatively low, i.e. for NO in the exhaust gas x is too low to convert in the SCR reactor

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