Device and method for the recovery of waste heat of an internal combustion engine

Abstract

The invention relates to a device and a method for the recovery of waste heat from an internal combustion engine ( 2 ). A feed pump ( 6 ), a heat exchanger ( 8 ), an expansion engine ( 10 ) and a capacitor ( 12 ) are arranged in a circuit ( 4 ) containing a circulating working medium. A steam accumulator ( 40 ) for storing the vaporous working medium is also arranged in the circuit ( 4 ).

1 . A device for the recovery of waste heat from an internal combustion engine comprising a circuit in which a feed pump, at least one heat exchanger, an expansion engine and a condenser are arranged, wherein said circuit contains a circulating working medium, wherein a steam accumulator for storing the vaporous working medium is also arranged in the circuit. 
     
     
         2 . The device according to  claim 1 , wherein the steam accumulator is situated in a line of the circuit between heat exchanger and expansion engine. 
     
     
         3 . The device according to  claim 1 , wherein the steam accumulator is directly connected to the heat exchanger via a branch line. 
     
     
         4 . The device according to  claim 1 , wherein the steam accumulator is directly connected to the expansion engine via a branch line. 
     
     
         5 . The device according to  claim 1 , wherein the steam accumulator is connected to the line between the heat exchanger and the expansion engine via a branch line. 
     
     
         6 . The device according to  claim 3 , wherein a controllable valve is disposed in the branch line. 
     
     
         7 . The device according to  claim 2 , wherein the steam accumulator is situated in a bypass connection, which is connected in parallel with the expansion engine. 
     
     
         8 . The device according to  claim 7 , wherein the steam accumulator is connected to the bypass connection via a multi-port-valve, via which steam is accommodated or steam is released to lines to the expansion engine or to the condenser via lines. 
     
     
         9 . The device according to  claim 7 , wherein the steam accumulator has a controllable valve on the side facing the heat exchanger and an overflow valve on the opposite side. 
     
     
         10 . A method for the recovery of waste heat from an internal combustion engine for a device according to  claim 1 , wherein steam delivered from the heat exchanger is accommodated in the steam accumulator and is released from said steam accumulator when a load demand is placed on the expansion engine. 
     
     
         11 . The method according to  claim 10 , wherein pressure pulsations and pressure oscillations are reduced by steam being released from the steam accumulator and/or being accommodated by said steam accumulator. 
     
     
         12 . The method according to  claim 10 , wherein intervention is made into the regulation of the evaporation pressure by the accommodation and release of steam by the steam accumulator being actively controlled via a controllable valve.