Fuel oil heat exchanger utilizing heat pipes

Abstract

A heat exchanger includes a heat exchanger housing having a first flow path with a first inlet and a first outlet, and having a second flow path with a second inlet and a second outlet. A first fluid flows from the first inlet to the first outlet in the first flow path, and a second fluid flows from the second inlet to the second outlet in the second flow path. A heat pipe array within the housing extends between the first flow path and the second flow path for transferring heat from the first fluid to the second fluid.

1 . A heat exchanger for transferring heat from a first fluid to a second fluid, the heat exchanger comprising:
 a heat exchanger housing having a first flow path with a first inlet and a first outlet, and having a second flow path with a second inlet and a second outlet; and   a heat pipe array within the housing and extending between the first flow path and the second flow path for transferring heat from the first fluid flowing from the first inlet to the first outlet in the first flow path to the second fluid flowing from the second inlet to the second outlet in the second flow path.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the first fluid is oil. 
     
     
         3 . The heat exchanger of  claim 1 , wherein the second fluid is fuel. 
     
     
         4 . The heat exchanger of  claim 1 , wherein the first fluid flows in a first chamber in the housing positioned between the first inlet and first outlet. 
     
     
         5 . The heat exchanger of  claim 4 , wherein the second fluid flows in a second chamber in the housing positioned between the second inlet and the second outlet. 
     
     
         6 . The heat exchanger of  claim 5 , and further comprising:
 a wall separating the first chamber from the second chamber in which the heat pipe array is held.   
     
     
         7 . The heat exchanger of  claim 6 , wherein the wall is made out of a conductive material to transfer heat from the first chamber to the second chamber. 
     
     
         8 . The heat exchanger of  claim 1 , wherein each heat pipe in the heat pipe array contains a working fluid that is capable of phase-change heat transfer. 
     
     
         9 . The heat exchanger of  claim 8 , wherein an interior surface of each heat pipe in the heat pipe array is covered with a wick structure layer to wick the working fluid. 
     
     
         10 . A heat exchanger for use in gas turbine engines, comprising:
 a first flow path for oil;   a second flow path for fuel; and   a plurality of heat pipes arranged in a matrix configuration, wherein each of the heat pipes comprises:
 a first end for contacting the oil in the first flow path and a second end for contacting the fuel in the second flow path; and 
 a working fluid contained in a hollow cavity in the heat pipe to transfer heat between the oil and the fuel. 
   
     
     
         11 . The heat exchanger of  claim 10 , wherein the working fluid transfers heat through phase-change heat transfer. 
     
     
         12 . The heat exchanger of  claim 10 , wherein an interior surface of each of the plurality of heat pipes are covered with a wick structure layer. 
     
     
         13 . The heat exchanger of  claim 10 , wherein the plurality of heat pipes are held in a housing comprising:
 a first flow path in a first chamber with an oil inlet and an oil outlet;   a second flow path in a second chamber with a fuel inlet and a fuel outlet; and   a wall separating the first chamber from the second chamber in which the plurality of heat pipes is held.   
     
     
         14 . The heat exchanger of  claim 13 , wherein the first ends of the heat pipes are positioned in the hot oil flow path to absorb heat from the oil to cool the oil. 
     
     
         15 . The heat exchanger of  claim 13 , wherein the second ends of the heat pipes are positioned in the cold fuel flow path to release heat into the fuel to heat the fuel. 
     
     
         16 . A method comprising:
 contacting first ends of a plurality of heat pipes in a heat pipe heat exchanger with oil;   absorbing heat from the oil into the first ends of the heat pipes in the heat pipe heat exchanger;   transferring heat from the first ends of the heat pipes to second ends of the heat pipes;   contacting the second ends of the heat pipes with fuel; and   releasing heat from the second ends of the heat pipes into the fuel.   
     
     
         17 . The method of  claim 16 , wherein the oil is cooled as heat is absorbed from the oil into the heat pipes in the heat pipe heat exchanger. 
     
     
         18 . The method of  claim 16 , wherein the fuel is warmed as heat is released into the fuel from the heat pipes in the heat pipe heat exchanger. 
     
     
         19 . The method of  claim 16 , wherein the heat is transferred through the heat pipes in the heat pipe heat exchanger with a phase-change working fluid contained in each of the heat pipes. 
     
     
         20 . The method of  claim 16 , and further comprising:
 moving oil through a first chamber of the heat pipe heat exchanger positioned between an oil inlet and an oil outlet; and   moving fuel through a second chamber of the heat pipe heat exchanger positioned between a fuel inlet and a fuel outlet.