Waste heat recovery system having a working fluid circuit

Abstract

The invention relates to a waste heat recovery system having a working fluid circuit (1) for an internal combustion engine, comprising a first heat exchanger (2a) connected in an exhaust gas line (3) of the internal combustion engine (5) and a second heat exchanger (2b) inserted into a line, which are part of the working fluid circuit (1), which has at least an expansion machine (11), a condenser (12), and a fluid pump. According to the invention, a waste heat recovery system that is improved in particular in respect of an efficiency of the system is provided. This is achieved in that each of the two heat exchangers (2a, 2b) is assigned a fluid pump (15a, 15b). Said fluid pumps (15a, 15b) are combined in a two-stroke vane cell pump (16).

1 . A heat recovery system having a working fluid circuit ( 1 ), the heat recovery system comprising a first heat exchanger ( 2   a ) connected in an exhaust gas line ( 3 ) of an internal combustion engine ( 5 ) and a second heat exchanger ( 2   b ) inserted into a line, wherein the first and second heat exchangers ( 2   a ,  2   b ) are part of the working fluid circuit ( 1 ), wherein the working fluid circuit also has at least an expansion machine ( 11 ), a condenser ( 12 ) and first and second fluid pumps ( 15   a ,  15   b ), and wherein the first and second heat exchangers ( 2   a ,  2   b ) are respectively connected to the first and second fluid pumps ( 15   a ,  15   b ). 
     
     
         2 . The heat recovery system according to  claim 1 , characterized in that the first and second fluid pumps ( 15   a ;  15   b ) are combined in a double pump. 
     
     
         3 . The heat recovery system according to  claim 2 , characterized in that the double pump is a two-stroke vane cell pump ( 16 ). 
     
     
         4 . The heat recovery system according to  claim 3 , characterized in that a first displacement chamber ( 24   a ) of the vane cell pump ( 16 ) is connected to the first heat exchanger ( 2   a ) via a first supply line ( 25   a ) and a second displacement chamber ( 24   b ) of the vane cell pump ( 16 ) is connected to the second heat exchanger ( 2   b ) via a second supply line ( 25   b ). 
     
     
         5 . The heat recovery system according to  claim 3 , characterized in that the vane cell pump ( 16 ) is configured to be operated with respect to a delivery quantity distribution into the first displacement chamber ( 24   a ) and into the second displacement chamber ( 24   b ) at a constant or adjustable total delivery quantity. 
     
     
         6 . The heat recovery system according to  claim 5 , characterized in that the vane cell pump ( 16 ) has a stator ( 20 ) configured to be radially displaced in relation to a rotor ( 21 ). 
     
     
         7 . The heat recovery system according to  claim 6 , characterized in that the vane cell pump has a spindle adjustment using a spindle ( 26 ) for displacing the stator ( 20 ). 
     
     
         8 . The heat recovery system according to  claim 7 , characterized in that the vane cell pump has a step motor ( 27 ) for actuating the spindle ( 26 ). 
     
     
         9 . The heat recovery system according to  claim 1 , characterized in that the line into which the second heat exchanger ( 2   b ) is inserted is an exhaust gas recirculation line ( 6 ) of the internal combustion engine ( 5 ).