Abstract A Rankine cycle system includes a first Rankine cycle ( 2 A) operated by a first working medium and a second Rankine cycle ( 2 B) operated by a second working medium. The first Rankine cycle ( 2 A) is constituted from an evaporator ( 3 A), an expander ( 4 ), a condenser ( 5 A) and a supply pump ( 6 A), and the second Rankine cycle ( 2 B) is constituted from an evaporator ( 3 B), the expander ( 4 ), a condenser ( 5 B) and a supply pump ( 6 c ). The evaporator ( 3 A) in the first Rankine cycle ( 2 A) and the evaporator ( 3 B) in the second Rankine cycle ( 2 B) are disposed at locations upstream and downstream of an exhaust emission control device ( 8 ) mounted in an exhaust passage ( 7 ) for the internal combustion engine ( 1 ). The first working medium has a boiling point higher than that of the second working medium, and the capacity of the pump ( 6 A) in at least the first Rankine cycle ( 2 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.
A Rankine cycle system for an internal combustion engine, comprising a first Rankine cycle ( 2 A) operated by a first working medium and a second Rankine cycle ( 2 B) operated by a second working medium, each of the Rankine cycles ( 2 A and 2 B) being comprised of an evaporator ( 3 A, 3 B) for heating a liquid-phase working medium by waste heat from the internal combustion engine ( 1 ) to generate a vapor, an expander ( 4 ) for converting the heat energy of the vapor discharged by said evaporator ( 3 A, 3 B) into a mechanical energy, a condenser ( 5 A, 5 B) for cooling the vapor discharged by said expander ( 4 ) to return the vapor into the liquid-phase working medium, and a supply pump ( 6 A, 6 B) for supplying the water discharged by said condenser ( 5 A, 5 B) to said evaporator ( 3 A, 3 B), wherein said evaporator ( 3 A) in said first Rankine cycle ( 2 A) and said evaporator ( 3 B) in said second Rankine cycle ( 2 B) are respectively disposed at locations upstream and downstream of an exhaust emission control device ( 8 ) mounted in an exhaust passage ( 7 ) for the internal combustion engine ( 1 ); said first working medium is of a boiling point higher than that of said second working medium; and the capacity of said supply pump ( 6 A) in at least said first Rankine cycle ( 2 A) is variable.
Claim 2
Dependent Claim
262 words
A Rankine cycle system for an internal combustion engine, comprising a first Rankine cycle ( 2 A) operated by a first working medium and a second Rankine cycle ( 2 B) operated by a second working medium, each of the Rankine cycles ( 2 A and 2 B) being comprised of an evaporator ( 3 A, 3 B) for heating a liquid-phase working medium by waste heat from the internal combustion engine ( 1 ) to generate a vapor, an expander ( 4 ) for converting the heat energy of the vapor discharged by said evaporator ( 3 A, 3 B) into a mechanical energy, a condenser ( 5 A, 5 B) for cooling the vapor discharged by said expander ( 4 ) to return the vapor into the liquid-phase working medium, and a supply pump ( 6 A, 6 B) for supplying the water discharged by said condenser ( 5 A, 5 B) to said evaporator ( 3 A, 3 B), wherein said evaporator ( 3 A) in said first Rankine cycle ( 2 A) and said evaporator ( 3 B) in said second Rankine cycle ( 2 B) are respectively disposed at locations upstream and downstream of an exhaust emission control device ( 8 ) mounted in an exhaust passage ( 7 ) for the internal combustion engine ( 1 ); said first working medium is of a boiling point higher than that of said second working medium; and the capacity of said supply pump ( 6 A) in at least said first Rankine cycle ( 2 A) is variable.
Claim 3
Dependent Claim
97 words
A Rankine cycle system for an internal combustion engine according to claim 1 , wherein said expander ( 4 ) includes higher-pressure expanding portions ( 33 ) and lower-pressure expanding portions ( 50 ), so that outputs from both of said expanding portions ( 33 and 50 ) can be united together and output from a common rotary shaft ( 21 ); the vapor of said first working medium is supplied to said higher-pressure expanding portions ( 33 ); and the vapor of said second working medium is supplied to said lower-pressure expanding portions ( 50 ).