To provide a steam injection system of an engine which can suppress NOx to a low level throughout the year while suppressing an increase of fuel consumption to dispense with adjusting an engine in each season like at the beginning of the month.
This steam injection system of an engine is provided with a steam line 9 connected to a supply air pipe 7 communicating with a supply air port of each cylinder to make injection capable of steam from a steam generating source 5 to the supply air port, a flow regulating valve 11 interposed in the steam line 9 to make an injection amount variable of steam by inputting a valve opening adjusting signal, and a control means 21 calculating an amount of water necessary for humidity of air supplied to the supply air pipe 7 obtaining the target absolute humidity to additionally output to the flow regulating valve 11 the valve opening adjusting signal injecting this necessary amount of water.
MIMURA YOSHIHISA
KOMATSU JUNICHI
KIMURA HIROAKI
SAKAGAMI TAKEYUKI
