Gas-fueled internal combustion engine and control method for gas-fueled internal combustion engine

Abstract

In a gas-fueled internal combustion engine, an ignition device (16, 6O, 62, 64, 66) is arranged in a moving direction of a stream of the gaseous fuel injected from an in-cylinder injection valve (40) in a combustion chamber. The ignition device can directly ignite the fuel stream and diffusive combustion of the gaseous fuel can be executed by sequentially injecting the gaseous fuel toward a flamecreated by the ignition. Further, premix combustion of the gaseous fuel can also be performed by igniting an air-fuel mixture after the gaseous fuel injected from the in-cylinder injection valve has been sufficiently mixed with the air. As an operation mode of the engine, a lean premix combustion operation is selected when the engine is operated in a prescribed operation region, and the operationmode is changed to a diffusive combustion operation when the engine is operated in a higher load operation region than the prescribed operation region.

Description

technical field [0001] The present invention relates to a gas fueled internal combustion engine capable of operating on a gaseous fuel such as hydrogen. Background technique [0002] As described in Japanese Patent Application Publication No. JP-A-6-88542, a gaseous fuel such as hydrogen can be used as a fuel for an internal combustion engine. Hydrogen has a wide flammability range of 4-75 volume percent, and can be easily burned in an extremely lean mixture (air excess ratio λ equal to or greater than about 4). Therefore, if hydrogen is used as fuel for an internal combustion engine, power can be extracted even at an extremely lean air-fuel ratio, making it possible to realize so-called "ultra-lean combustion operation." [0003] In ultra-lean burn operation, the throttle valve can be fully opened, thereby reducing pumping losses and lowering combustion temperatures, which in turn leads to reduced cooling losses. The reduction in pumping and cooling losses increases engin...

AI Technical Summary

Problems solved by technology

[0008] Such rapid combustion results in an increase in the combustion temperature in the combustion chamber

As a result, as mentioned above, cooling losses increase and NOx emissions skyrocket

In addition, in practice, the rate of rise of the in-cylinder pressure is significantly higher, so that the combustion noise and the damage to the engine body are significantly increased

These factors make it difficult to operate conventional hydrogen internal combustion engines under sustained high loads

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