Heat recovery system and heat exchanger

Abstract

An exhaust gas heat recovery system may include a housing, a valve member, and a heat exchanger. The housing may include an inlet, an outlet, a first exhaust gas pathway in communication with the inlet and outlet, and a second exhaust gas pathway in communication with the inlet and outlet. The valve member may be disposed within the housing and may be movable between first and second positions. In the first position, the valve member may allow fluid flow through the first exhaust gas pathway and substantially prevent fluid flow through the second exhaust gas pathway. In the second position, the valve member may allow fluid flow through the second exhaust gas pathway. The heat exchanger may be in communication with the second exhaust gas pathway and may include a conduit containing a fluid in thermal communication with exhaust gas when the valve member is in the second position.

What is claimed is: 
     
         1 . A system for recovering heat from exhaust gas of an internal combustion engine, the system comprising:
 a body including an inlet, an outlet, a first exhaust gas pathway in communication with the inlet and the outlet, and a second exhaust gas pathway in communication with the inlet and the outlet, the body adapted to receive exhaust gas from the internal combustion engine;   a valve member disposed within the body and movable between a first position allowing fluid flow through the first exhaust gas pathway and restricting fluid flow through the second exhaust gas pathway and a second position allowing fluid flow through the second exhaust gas pathway; and   a heat exchanger in communication with the second exhaust gas pathway and including first, second, third and fourth cooling plates arranged parallel to each other, the first and second cooling plates defining a first working fluid cavity therebetween, the third and fourth cooling plates defining a second working fluid cavity therebetween, the second and third cooling plates defining a first exhaust passage therebetween, the first cooling plate defining a second exhaust passage that is parallel to the first exhaust passage, the first and second exhaust passages are in communication with the second exhaust gas pathway.   
     
     
         2 . The system of  claim 1 , wherein the heat exchanger includes a housing in which the first, second, third and fourth cooling plates are disposed, the housing includes a working fluid inlet and a working fluid outlet in fluid communication with the first and second working fluid cavities. 
     
     
         3 . The system of  claim 2 , wherein the first, second, third and fourth cooling plates are arranged parallel to a direction of fluid flow through the first exhaust gas pathway. 
     
     
         4 . The system of  claim 3 , wherein the heat exchanger includes first and second deflector plates disposed within the housing at respective first and second opposing edges of the first, second, third and fourth cooling plates. 
     
     
         5 . The system of  claim 4 , wherein the housing includes a proximal end attached to the body and a distal end opposite the proximal end, and wherein the working fluid inlet and the working fluid outlet are disposed in respective corners of the housing at or near the distal end. 
     
     
         6 . The system of  claim 5 , wherein the first working fluid cavity defines first and second generally U-shaped flow paths extending from the working fluid inlet and providing working fluid to the working fluid outlet, the first U-shaped flow path is disposed within the second U-shaped flow path. 
     
     
         7 . The system of  claim 6 , wherein the heat exchanger includes first and second ribs defining the first generally U-shaped flow path and defining the second generally U-shaped flow path, at least one of the first and second ribs including leakage openings through which working fluid leaks between the first and second generally U-shaped flow paths. 
     
     
         8 . The system of  claim 7 , wherein the first rib is generally U-shaped and the second rib is generally straight. 
     
     
         9 . The system of  claim 6 , wherein the heat exchanger includes first and second fin packs attached to the second and third cooling plates, respectively, and disposed in the first and second exhaust passages, respectively. 
     
     
         10 . The system of  claim 4 , wherein the housing includes a proximal end attached to the body and a distal end opposite the proximal end, and wherein the working fluid inlet and the working fluid outlet are disposed along a line extending between the distal and proximal ends and guide exhaust gas in a U-shaped path through the heat exchanger. 
     
     
         11 . The system of  claim 10 , wherein each of the first, second and third cooling plates include a plurality of dimples protruding into one of the first and second exhaust passages. 
     
     
         12 . The system of  claim 1 , further comprising a deflector attached to edges of the first, second, third and fourth cooling plates adjacent the body, the deflector preventing leakage of exhaust gas between the valve member and the edges of the first, second, third and fourth cooling plates when the valve member is in the second position, and wherein the valve member abuts the deflector in the second position. 
     
     
         13 . A system for recovering heat from exhaust gas of an internal combustion engine, the system comprising:
 a body including an inlet, an outlet, a first exhaust gas pathway in communication with the inlet and the outlet, and a second exhaust gas pathway in communication with the inlet and the outlet, the body adapted to receive exhaust gas from the internal combustion engine;   a valve member disposed within the body and movable between a first position allowing fluid flow through the first exhaust gas pathway and restricting fluid flow through the second exhaust gas pathway and a second position allowing fluid flow through the second exhaust gas pathway; and   a heat exchanger in communication with the second exhaust gas pathway and including a plurality of cooling plates arranged parallel to each other and defining an exhaust passage and a working fluid passage, the exhaust passage defining a generally U-shaped flow path therethrough, the working fluid passage including first and second generally U-shaped flow paths receiving working fluid from a working fluid inlet and providing working fluid to a working fluid outlet, the first U-shaped flow path is disposed within the second U-shaped flow path, wherein a divider defines the first and second generally U-shaped flow paths and includes leakage openings through which working fluid leaks between the first and second generally U-shaped flow paths.   
     
     
         14 . The system of  claim 13 , wherein the plurality of cooling plates includes first, second, third and fourth cooling plates, the first and second cooling plates defining the working fluid passage therebetween, the third and fourth cooling plates defining another working fluid passage therebetween, the second and third cooling plates defining the exhaust passage therebetween, the first cooling plate defining another exhaust passage. 
     
     
         15 . The system of  claim 14 , wherein the heat exchanger includes another divider defining the first and second generally U-shaped flow paths and including leakage openings through which working fluid leaks between the first and second generally U-shaped flow paths. 
     
     
         16 . The system of  claim 15 , wherein one of the dividers is generally U-shaped and the other divider is generally straight. 
     
     
         17 . The system of  claim 13 , wherein the cooling plates are arranged parallel to a direction of fluid flow through the first exhaust gas pathway. 
     
     
         18 . The system of  claim 13 , wherein the heat exchanger includes a housing in which the cooling plates are disposed. 
     
     
         19 . The system of  claim 18 , wherein the heat exchanger includes first and second deflector plates disposed within the housing at respective first and second opposing edges of the cooling plates. 
     
     
         20 . The system of  claim 19 , wherein the housing includes a proximal end attached to the body and a distal end opposite the proximal end, and wherein the working fluid inlet and the working fluid outlet are disposed in respective corners of the housing at or near the distal end. 
     
     
         21 . The system of  claim 20 , wherein the heat exchanger includes a fin pack disposed between adjacent cooling plates and disposed in the exhaust passage. 
     
     
         22 . The system of  claim 18 , wherein the housing includes a proximal end attached to the body and a distal end opposite the proximal end, and wherein the working fluid inlet and the working fluid outlet are disposed along a line extending between the distal and proximal ends and guide exhaust gas in a U-shaped path through the heat exchanger. 
     
     
         23 . The system of  claim 22 , wherein at least one of the cooling plates includes a plurality of dimples protruding into the exhaust passage. 
     
     
         24 . The system of  claim 13 , further comprising a deflector attached to edges of the cooling plates adjacent the body, the deflector preventing leakage of exhaust gas between the valve member and the edges of the cooling plates when the valve member is in the second position, and wherein the valve member abuts the deflector in the second position.