Exhaust gas heat recovery system in internal combustion engine

摘要

An exhaust gas heat recovery system wherein: the system comprises an exhaust gas economizer having of heat transfer sections including a preheating section, an evaporating section and a superheating section, a feed water heater, a steam separation drum, a low pressure steam generator; and a mixed-pressure turbine; a temperature gradient of circulating water and a temperature gradient of exhaust gases are made substantially equal to each other in the preheating section of the exhaust gas economizer to prevent an exhaust gas economizer tube from being corroded by generated sulfuric acid; and low pressure steam can be effectively utilized by use of the mixed-pressure turbine.