Exhaust heat recovery system having a working fluid circuit and method for operating such an exhaust heat recovery system

Abstract

The invention relates to an exhaust heat recovery system having a working fluid circuit (1) carrying a working fluid, having a heat exchanger (2) which is connected in an exhaust line (3) of an internal combustion engine (5) and which is a part of the working fluid circuit (1) together with at least one expansion machine (11), a condenser (12), and a fluid pump (15). The aim of the invention is to provide an exhaust heat recovery system, which is improved with respect to known systems. This is achieved in that the exhaust heat recovery system has a device (27) for avoiding damage to the expansion machine (11) that is caused by liquid components of the working fluid. The device (11) is, for example, a container (21), a calming container (28, 28a), a line section (36) or a filter (26), or the device (11) has at least one such component.

1 . An exhaust heat recovery system having a working fluid circuit ( 1 ) carrying a working fluid, comprising at least one heat exchanger ( 2 ) which is connected in an exhaust gas line ( 3 ) of an internal combustion engine ( 5 ) and which is a part of the working fluid circuit ( 1 ) together with at least one expansion machine ( 11 ), a condenser ( 12 ), and at least one fluid pump ( 15 ), characterized in that the exhaust heat recovery system comprises a device ( 27 ) for avoiding damage to the expansion machine ( 11 ) caused by liquid components of the working fluid. 
     
     
         2 . The exhaust heat recovery system as claimed in  claim 1 , characterized in that the device ( 27 ) is arranged in the working fluid circuit between an outlet from the heat exchanger ( 2 ) and the expansion machine ( 11 ). 
     
     
         3 . The exhaust heat recovery system as claimed in  claim 1 , characterized in that the device ( 27 ) is configured to separate the liquid components from the working fluid. 
     
     
         4 . The exhaust heat recovery system as claimed in  claim 1 , characterized in that the device ( 27 ) comprises a guide device. 
     
     
         5 . The exhaust heat recovery system as claimed in  claim 3 , characterized in that the device ( 27 ) comprises at least one tangential inflow inlet ( 22 ,  22   a ). 
     
     
         6 . The exhaust heat recovery system as claimed in  claim 1 , characterized in that the device ( 27 ) is a filter ( 26 ). 
     
     
         7 . The exhaust heat recovery system as claimed in  claim 1 , characterized in that the device ( 27 ) comprises a heater ( 37 ). 
     
     
         8 . The exhaust heat recovery system as claimed in  claim 1 , characterized in that the device ( 27 ) comprises a liquid outlet ( 31 ). 
     
     
         9 . The exhaust heat recovery system as claimed in  claim 1 , characterized in that the device ( 27 ) comprises a nozzle ( 35 ). 
     
     
         10 . The exhaust heat recovery system as claimed in  claim 1 , characterized in that the device ( 27 ) comprises a magnet ( 37 ). 
     
     
         11 . A method for operating an exhaust heat recovery system having a working fluid circuit ( 1 ) carrying a working fluid, the exhaust heat recovery system comprising at least one heat exchanger ( 2 ) which is connected in an exhaust gas line ( 3 ) of an internal combustion engine ( 5 ) and which is a part of the working fluid circuit ( 1 ) together with at least one expansion machine ( 11 ), a condenser ( 12 ), and at least one fluid pump ( 15 ), of the method comprising using a device ( 27 ) to separate liquid components from the working fluid and/or to render harmless the liquid components so as to exclude damage to the expansion machine ( 11 ) from the liquid components. 
     
     
         12 . The exhaust heat recovery system as claimed in  claim 3 , characterized in that the device ( 27 ) is a container ( 21 ). 
     
     
         13 . The exhaust heat recovery system as claimed in  claim 12 , characterized in that the container ( 21 ) has therein a guide plate ( 24 ). 
     
     
         14 . The exhaust heat recovery system as claimed in  claim 13 , characterized in that the container ( 21 ) comprises at least one tangential inflow inlet ( 22 ,  22   a ). 
     
     
         15 . The exhaust heat recovery system as claimed in  claim 3 , characterized in that the device ( 27 ) is a calming container ( 28 ,  28   a ). 
     
     
         16 . The exhaust heat recovery system as claimed in  claim 15 , characterized in that the calming container ( 28 ,  28   a ) has therein a baffle plate ( 29 ). 
     
     
         17 . The exhaust heat recovery system as claimed in  claim 16 , characterized in that the calming container ( 28 ,  28   a ) comprises at least one tangential inflow inlet ( 22 ,  22   a ). 
     
     
         18 . The exhaust heat recovery system as claimed in  claim 3 , characterized in that the device ( 27 ) is a line portion ( 36 ) of the working fluid circuit ( 1 ). 
     
     
         19 . The exhaust heat recovery system as claimed in  claim 19 , characterized in that a magnet ( 37 ) is arranged on the outside of the line portion ( 36 ) such that the magnet ( 37 ) separates electrically charged fluid droplets ( 25 ) out of the working fluid flowing through the line portion ( 36 ). 
     
     
         20 . The exhaust heat recovery system as claimed in  claim 18 , characterized in that the line portion ( 36 ) comprises at least one tangential inflow inlet ( 22 ,  22   a ).