Exhaust heat recovery apparatus

Abstract

An evaporator has tubes, and evaporates working fluid therein by heat of exhaust gas. A condenser emits heat of the working fluid toward coolant so as to condense the working fluid, and returns the condensed working fluid to the evaporator. A fin for increasing an area for transmitting heat is disposed between the tubes, and is connected to the tubes. The fin has an operation force reducing part for reducing an operation force applied to the fin in accordance with a thermal expansion difference between the tubes. The operation force reducing part is disposed at a midpoint of the fin between the tubes.

1 . An exhaust heat recovery apparatus comprising: 
 an evaporator having a plurality of tubes arranged in an arrangement direction, and a fin for increasing an area for transmitting heat, the evaporator evaporating working fluid therein by heat of exhaust gas discharged from an internal combustion engine; and    a condenser for emitting heat of the working fluid flowing from the evaporator toward coolant of the internal combustion engine so as to condense the working fluid, and returning the condensed working fluid to the evaporator, wherein    the fin is disposed between the tubes in the arrangement direction, and connected to a face of the tube,    the fin has an operation force reducing part for reducing an operation force applied to the fin in accordance with a thermal expansion difference between the tubes in a tube longitudinal direction, and    the operation force reducing part is disposed at a midpoint of the fin in the arrangement direction.    
   
   
       2 . The exhaust heat recovery apparatus according to  claim 1 , wherein 
 the fin is a corrugated fin having a wave shape, and separated into a plurality of fin layers in the arrangement direction, and    the operation force reducing part is a non-connection part such that opposing fin layers are not connected to each other.    
   
   
       3 . The exhaust heat recovery apparatus according to  claim 2 , further comprising 
 a separation plate for separating the opposing fin layers, wherein    the separation plate is connected to only one of the opposing fin layers.    
   
   
       4 . The exhaust heat recovery apparatus according to  claim 1 , wherein 
 the fin is a corrugated fin having a wave shape, and separated into a plurality of fin layers in the arrangement direction, and    opposing fin layers are displaceable between the tubes, when at least one of the opposing fin layers has the operation force reducing part.    
   
   
       5 . The exhaust heat recovery apparatus according to  claim 4 , further comprising 
 a separation plate for separating the opposing fin layers, wherein    the separation plate is connected to only one of the opposing fin layers.    
   
   
       6 . The exhaust heat recovery apparatus according to  claim 1 , wherein 
 the operation force reducing part is a bent part, at which the midpoint of the fin is bent.    
   
   
       7 . The exhaust heat recovery apparatus according to  claim 6 , wherein 
 the bent part is disposed at an approximately center position of the fin between the tubes in the arrangement direction, and    the bent part has an obtuse angle.    
   
   
       8 . The exhaust heat recovery apparatus according to  claim 6 , wherein 
 the bent part has a S-letter shape.    
   
   
       9 . The exhaust heat recovery apparatus according to  claim 6 , wherein 
 the fin is a corrugated fin having a wave shape.    
   
   
       10 . The exhaust heat recovery apparatus according to  claim 1 , further comprising 
 a valve mechanism for opening and closing a passage, through which the working fluid returns from the condenser to the evaporator, in accordance with at least one of a pressure of the working fluid, a temperature of the coolant and a temperature of the working fluid.