TURBOCHARGER, TWO-STAGE TURBO SYSTEM, AND CONTROL METHOD FOR TWO-STAGE TURBO SYSTEM

摘要

A turbocharger includes: at least two scroll passages, and a first range of the nozzle flow passage into which the exhaust gas flowing through the first scroll passage is introduced does not overlap with a second range of the nozzle flow passage into which the exhaust gas flowing through the second scroll passage is introduced, in a circumferential direction of the nozzle flow passage. The first scroll passage includes: a division wall disposed along a flow direction of the exhaust gas within a predetermined range in the first scroll passage, the division wall dividing the first scroll passage into a radially outer side scroll passage and a radially inner side scroll passage positioned on a radially inner side of the radially outer side scroll passage, and having a communication hole which brings the radially outer side scroll passage and the radially inner side scroll passage into communication; and a flow-rate control valve disposed on an upstream side of the division wall, for adjusting a flow rate of the exhaust gas flowing through the radially outer side scroll passage and the radially inner side scroll passage.