SURGE SUPPRESSION DEVICE, EXHAUST TURBINE TYPE TURBOCHARGER AND SURGE SUPPRESSION METHOD

A surge suppression device for suppressing surge in an exhaust turbine-type turbocharger includes: a high-pressure tank configured to accumulate high-pressure gas with a higher pressure than atmospheric pressure; a high-pressure gas injection line connecting the high-pressure tank and an upstream intake passage on an upstream side of a compressor of the turbocharger; an on-off valve configured to open and close the high-pressure gas injection line; and a control device configured to control the on-off valve on the basis of a relationship between a pressure ratio of the compressor of the turbocharger and an intake flow rate.