Regenerative Rankine Cycle For Vehicles

Abstract

A system for regenerating energy in a vehicle. The system includes a Rankine loop having a heat exchanger and a preheater configured to pre-heat a Rankine working fluid prior to the Rankine working fluid being heated at the heat exchanger. The system also includes an engine coolant loop configured to direct engine coolant to and from the pre-heater, and an exhaust loop configured to direct engine exhaust to and from the heat exchanger.

What is claimed is: 
     
         1 . A system for regenerating energy in a vehicle comprising:
 a Rankine loop including a heat exchanger and a preheater configured to pre-heat a Rankine working fluid prior to the Rankine working fluid being heated at the heat exchanger;   an engine coolant loop configured to direct engine coolant to and from the pre-heater; and   an exhaust loop configured to direct engine exhaust to and from the heat exchanger.   
     
     
         2 . The system of  claim 1 , wherein the preheater is configured to transfer heat from the engine coolant loop to the exhaust loop. 
     
     
         3 . The system of  claim 1 , wherein the heat exchanger is configured to output engine exhaust gas and a heated Rankine working vapor. 
     
     
         4 . The system of  claim 3 , wherein the Rankine loop further comprises an expander configured to drive a generator, the generator configured to charge a battery. 
     
     
         5 . The system of  claim 4 , wherein the preheater is a first preheater, the system further comprising a second preheater between the expander and a condenser. 
     
     
         6 . The system of  claim 3 , wherein the Rankine loop further includes a Rankine condenser configured to cool and convert the heated Rankine working vapor into the Rankine working fluid. 
     
     
         7 . The system of  claim 1 , further comprising an air cooling loop including an evaporator, a compressor, an air cooling condenser, and a thermal expansion valve;
 wherein the air cooling loop is independent of the Rankine loop.   
     
     
         8 . The system of  claim 1 , further comprising an air cooling loop including an evaporator, a compressor, an air cooling condenser, and a thermal expansion valve;
 wherein the air cooling loop is in cooperation with the Rankine loop to cool the Rankine working vapor.   
     
     
         9 . The system of  claim 3 , wherein the heat exchanger is a first heat exchanger, and the system further comprises a second heat exchanger in receipt of the heated Rankine working vapor and configured to heat a passenger cabin of the vehicle. 
     
     
         10 . A system for regenerating energy in a vehicle comprising:
 an engine coolant loop;   an exhaust loop; and   a Rankine loop including:
 a preheater; 
 a first heat exchanger configured to receive a Rankine fluid pre-heated by the preheater and hot exhaust from an engine of the vehicle, the first heat exchanger configured to output hot Rankine working vapor; 
 an expander configured to receive the hot Rankine working vapor; 
 a generator configured to be driven by the expander and charge a battery; and 
 a Rankine condenser configured to convert the hot Rankine working vapor back to the Rankine fluid. 
   
     
     
         11 . The system of  claim 10 , further comprising a second heat exchanger in receipt of the hot Rankine working vapor and configured to heat a passenger cabin of the vehicle. 
     
     
         12 . The system of  claim 10 , further comprising an air cooling loop independent of the Rankine loop, the engine coolant loop, and the exhaust loop. 
     
     
         13 . The system of  claim 10 , further comprising an air cooling loop including an evaporator, a compressor, an air cooling condenser, and a thermal expansion valve; and
 wherein the air cooling loop is in cooperation with the Rankine loop to cool the hot Rankine working vapor.   
     
     
         14 . The system of  claim 11 , further comprising an HVAC unit including the second heat exchanger, a heater core, and an evaporator of an air cooling loop. 
     
     
         15 . A method for regenerating energy in a vehicle comprising:
 directing a Rankine fluid of a Rankine loop to a preheater to pre-heat the Rankine fluid;   directing the preheated Rankine fluid and engine exhaust gas to a Rankine heat exchanger to further heat the preheated Rankine fluid using the engine exhaust gas to produce a hot Rankine working vapor;   inputting the hot Rankine working vapor into an expander to cause the expander to drive a generator configured to charge a battery; and   directing the hot Rankine working vapor to a Rankine condenser to convert the hot Rankine working vapor to the Rankine fluid.   
     
     
         16 . The method of  claim 15 , further comprising cooling the hot Rankine working vapor at the condenser with refrigerant of an air cooling loop. 
     
     
         17 . The method of  claim 15 , wherein the Rankine heat exchanger is a first heat exchanger, the method further comprising directing the hot Rankine working vapor to a second heat exchanger of an HVAC unit to heat a passenger cabin. 
     
     
         18 . The method of  claim 15 , further comprising pre-heating the Rankine fluid with a plurality of Rankine heat exchangers. 
     
     
         19 . The method of  claim 15 , further comprising directing hot engine coolant from the engine to the preheater to preheat the Rankine fluid. 
     
     
         20 . The method of  claim 15 , wherein the expander is a turbine.