Rankine cycle device of internal combustion engine

Abstract

A Rankine cycle system includes a first Rankine cycle (A) operated by a first working medium and a second Rankine cycle (B) operated by a second working medium. The first Rankine cycle (A) is constituted from an evaporator (A), an expander (), a condenser (A) and a supply pump (A), and the second Rankine cycle (B) is constituted from an evaporator (B), the expander (), a condenser (B) and a supply pump (). The evaporator (A) in the first Rankine cycle (A) and the evaporator (B) in the second Rankine cycle (B) are disposed at locations upstream and downstream of an exhaust emission control device () mounted in an exhaust passage () for the internal combustion engine (). The first working medium has a boiling point higher than that of the second working medium, and the capacity of the pump (A) in at least the first Rankine cycle (A) is variable. Thus, the efficiency of recovery of a waste heat from the internal combustion engine by the Rankine cycle system can be enhanced to the maximum, and the activation of the exhaust emission control device can be promoted.