Patent ID: 6845618

Claim:
A Rankine cycle system for an internal combustion engine, including an evaporator ( 3 ) for heating a liquid-phase working medium by a waste heat from an internal combustion engine ( 1 ) to generate a gas-phase working medium, an expander ( 4 ) for converting a heat energy of the gas-phase working medium discharged from said evaporator ( 3 ) into a mechanical energy, a condenser ( 5 ) for cooling the gas-phase working medium discharged from said expander ( 4 ) to restore the gas-phase working medium into the liquid-phase working medium, a tank ( 6 ) for storage of the liquid-phase working medium discharged from said condenser ( 5 ), and pumps ( 7 , 8 ) for supplying the liquid-phase working medium in said tank ( 6 ) to said evaporator ( 3 ), characterized in that said pumps ( 7 , 8 ) area lower-pressure pump ( 7 ) and a higher-pressure pump ( 8 ), said lower-pressure pump ( 7 ) having the liquid-phase working medium in said tank ( 6 ) pass through a cooling means ( 105 ) for the internal combustion engine ( 1 ), thereby heating and supplying the liquid-phase working medium to a dispensing valve ( 106 ), a portion of the liquid-phase working medium dispensed by said dispensing valve ( 106 ) being pressurized by said higher-pressure pump ( 8 ) and supplied to said evaporator ( 3 ), another portion of the liquid-phase working medium dispensed by said dispensing valve ( 106 ) being discharged to said tank ( 6 ) after characterized in that said pumps ( 7 , 8 ) are a lower-pressure pump ( 7 ) and a higher-pressure pump ( 8 ), said lower-pressure pump ( 7 ) having the liquid-phase working medium in said tank ( 6 ) pass through a cooling means ( 105 ) for the internal combustion engine ( 1 ), thereby heating and supplying the liquid-phase working medium to a dispensing valve ( 106 ), a portion of the liquid-phase working medium dispensed by said dispensing valve ( 106 ) being pressurized by said higher-pressure pump ( 8 ) and supplied to said evaporator ( 3 ), another portion of the liquid-phase working medium dispensed by said dispensing valve ( 106 ) being discharged to said tank ( 6 ) after characterized in that said pumps ( 7 , 8 ) are a lower-pressure pump ( 7 ) and a higher-pressure pump ( 8 ), said lower-pressure pump ( 7 ) having the liquid-phase working medium in said tank ( 6 ) pass through a cooling means ( 105 ) for the internal combustion engine ( 1 ), thereby beating and supplying the liquid-phase working medium to a dispensing valve ( 106 ), a portion of the liquid-phase working medium dispensed by said dispensing valve ( 106 ) being pressurized by said higher-pressure pump ( 8 ) and supplied to said evaporator ( 3 ), another portion of the liquid-phase working medium dispensed by said dispensing valve ( 106 ) being discharged to said tank ( 6 ) after dissipating its heat in an auxiliary ( 110 ).