System for converting thermal energy to mechanical energy in a vehicle

Abstract

A system for converting thermal energy to mechanical energy in a vehicle: A line circuit ( 35 ), a pump ( 36 ) for recirculating a medium in the line circuit, at least one evaporator ( 31, 32, 38 ) in which the medium is caused to absorb thermal energy from a heat source ( 4, 28 ) so that the medium becomes vaporised, a turbine ( 39 ) driven by the vaporised medium in order to generate mechanical energy, followed by a condenser arrangement ( 24, 42 ) in which the medium is caused to give off thermal energy so that it condenses. The condenser arrangement includes a first condenser ( 24 ) in which the medium gives off thermal energy to coolant which circulates in a cooling circuit, and a second condenser ( 42 ) downstream of the first condenser ( 24 ) with respect to the medium's direction of flow in the line circuit ( 35 ) and in which the medium gives off thermal energy to air at the temperature of the surroundings.

1 . A system for converting thermal energy to mechanical energy in a vehicle comprising:
 a cooling circuit configured for circulating a circulating coolant;   a line circuit, a pump for recirculating a medium in the line circuit, at least one evaporator at the line circuit in which the medium is caused to absorb thermal energy from a heat source for vaporising the medium;   a turbine configured and operable for having the vaporised medium pass by the turbine in order to cause the turbine to be driven by the vaporised medium in order for the turbine to generate mechanical energy;   a condenser arrangement configured and operable for then having the medium pass by the condenser arrangement and in which the medium is caused to give off thermal energy so that the medium condenses, the condenser arrangement comprising:   a first condenser in which the medium gives off thermal energy to the coolant which circulates in the cooling circuit; and   a second condenser downstream of the first condenser with respect to a direction of flow of the medium in the line circuit and in which the medium gives off thermal energy to air at the temperature of the surroundings.   
     
     
         2 . A system according to  claim 1 , furthering comprising a combustion engine powering the vehicle;
 a cooling system which circulates a second circulating coolant for cooling the engine; and   the cooling circuit being configured such that the coolant in the cooling circuit cools the medium in the first condenser such the medium in the first condenser is at a lower temperature than the second coolant which circulates in the engine cooling system.   
     
     
         3 . A system according to  claim 2 , wherein the cooling circuit comprises a second cooling system that is separate from the cooling system which cools the engine. 
     
     
         4 . A system according to  claim 1 , wherein the cooling circuit further comprises an air-cooled cooler in which the circulating coolant is at least partly cooled by air at the temperature of the surroundings. 
     
     
         5 . A system according to  claim 4 , wherein the cooling circuit comprises the first condenser and at least one further cooler for cooling a further medium. 
     
     
         6 . A system according to  claim 1 , further comprising a device configured for regulating the cooling of the medium in the first condenser. 
     
     
         7 . A system according to  claim 2 , further comprising an exhaust line for exhaust from the engine, at least one of the evaporators being at the exhaust line, so that the medium is caused to absorb thermal energy in the at least one evaporator from exhaust gases which are led out from the engine in the exhaust line. 
     
     
         8 . A system according to  claim 7 , further comprising a return line located and configured for returning exhaust gases from the exhaust line to the engine, at least one of the evaporators being at the return line, so that the medium is caused to absorb thermal energy in at least one of the evaporators from exhaust gases in the return line. 
     
     
         9 . A system according to  claim 8 , further comprising the vehicle includes a second turbine located and configured to being driven by the exhaust gases in the exhaust line; the system comprises at least one additional evaporator configured for absorbing thermal energy from exhaust gases in the exhaust line and at a location downstream in the exhaust gases flow of the second turbine, and the at least one additional evaporator absorbs thermal energy from recirculating exhaust gases which are led into the return line at a location upstream in the exhaust gases flow of the second turbine. 
     
     
         10 . A system according to  claim 9 , further comprising at least two of the evaporators arranged in series in the return line. 
     
     
         11 . A system according to  claim 2 , further comprising a return line located and configured for returning exhaust gases from the exhaust line to the engine, at least one of the evaporators being at the return line, so that the medium is caused to absorb thermal energy in the at least one evaporator from exhaust gases in the return line.