Generation of electricity from exhaust gas

摘要

A system for generating electricity from the exhaust gas flow from an i.c. engine comprises a turbine 3, an electricity generator 11 (e.g. a switched reluctance machine) and a turbine bypass path 5b. The relative proportions of exhaust gas flow through the turbine 3 and through the bypass path 5b are adjusted in response to the speed of rotation of the turbine 3. The electric current output from the generator 11 is adjusted in response to the actual or predicted exhaust gas pressure at a position upstream of the turbine 3 and the bypass path 5b.