Parallel Flow Heat Exchangers Incorporating Porous Inserts

Abstract

A parallel flow (minichannel or microchannel) evaporator includes a porous member inserted at the entrance of the evaporator channels which provides refrigerant expansion and pressure drop controls resulting in the elimination of refrigerant maldistribution and prevention of potential compressor flooding.

1 . A parallel flow (minichannel or microchannel) heat exchanger comprising:
 an inlet manifold extending longitudinally and having an inlet opening for conducting the flow of a fluid into said inlet manifold and a plurality of outlet openings for conducting the flow of fluid transversely from said inlet manifold;   a plurality of channels aligned in substantially parallel relationship and fluidly connected to said plurality of outlet openings for conducting the flow of fluid from said inlet manifold; and   an outlet manifold fluidly connected to said plurality of said channels for receiving the flow of fluid therefrom;   wherein said heat exchanger contains at least one porous member positioned within the flow path of said heat exchanger.   
   
   
       2 . A parallel flow heat exchanger as set forth in  claim 1  wherein said heat exchanger is an evaporator. 
   
   
       3 . A parallel flow heat exchanger as set forth in  claim 1  wherein said heat exchanger is a condenser. 
   
   
       4 . A parallel flow heat exchanger as set forth in  claim 1  wherein said porous member is in the form of an insert positioned in at least one channel. 
   
   
       5 . A parallel flow heat exchanger as set forth in  claim 4  wherein said porous insert is positioned at the channel entrance. 
   
   
       6 . A parallel flow heat exchanger of  claim 5  wherein the porous insert is positioned adjacent to the channel entrance. 
   
   
       7 . A parallel flow heat exchanger of  claim 5  wherein the porous insert is positioned inside the channel. 
   
   
       8 . A parallel flow heat exchanger of  claim 1  wherein the porous insert is positioned in the inlet manifold or in direct fluid communication with the inlet manifold. 
   
   
       9 . A parallel flow heat exchanger of  claim 1  wherein the porous insert is positioned in the outlet manifold or in direct fluid communication with the outlet manifold. 
   
   
       10 . A parallel flow heat exchanger of  claim 1  wherein the porous insert is positioned in the intermediate manifold or in direct fluid communication with the intermediate manifold. 
   
   
       11 . The porous insert of  claim 1  wherein said insert is made from a material selected from the group consisting of a metal and a ceramic. 
   
   
       12 . The porous insert of  claim 1  wherein said insert is made from a material selected from the group consisting of sintered metal, compressed metal, metal wool or metal wire. 
   
   
       13 . The porous insert of  claim 1  wherein said insert is positioned longitudinally along the manifold. 
   
   
       14 . The porous insert of  claim 1  wherein there is a gap between said insert and the manifold inner wall surface. 
   
   
       15 . The porous insert of  claim 1  wherein said insert is a composite of at least two different inserts. 
   
   
       16 . The porous insert of  claim 1  wherein said insert cross-section is non-rectangular. 
   
   
       17 . The porous insert of  claim 16  wherein said insert cross-section is a portion of a circle. 
   
   
       18 . The porous insert of  claim 1  wherein said inserts are of variable characteristics between at least two channels. 
   
   
       19 . The insert of  claim 16  wherein the variable characteristics are selected from the group of porosity, depth, insertion depth, and material. 
   
   
       20 . A parallel flow (minichannel or microchannel) heat exchanger comprising:
 an inlet manifold extending longitudinally and having an inlet opening for conducting the flow of a fluid into said inlet manifold and a plurality of outlet openings for conducting the flow of fluid transversely from said inlet manifold;   a plurality of channels aligned in substantially parallel relationship and fluidly connected to said plurality of outlet openings for conducting the flow of fluid from said inlet manifold; and   an outlet manifold fluidly connected to said plurality of said channels for receiving the flow of fluid therefrom;   wherein said heat exchanger contains at least one porous member positioned within the flow path of said heat exchanger, wherein said porous member is designed to provide for at least one of an expansion control and a pressure drop control in the system.   
   
   
       21 . A parallel flow heat exchanger as set forth in  claim 20  wherein said heat exchanger is an evaporator. 
   
   
       22 . A parallel flow heat exchanger as set forth in  claim 20  wherein said heat exchanger is a condenser. 
   
   
       23 . The heat exchanger of  claim 20  wherein the porous member functions as a primary expansion device. 
   
   
       24 . The heat exchanger of  claim 20  wherein the porous member functions as a secondary expansion device. 
   
   
       25 . A parallel flow heat exchanger as set forth in  claim 20  wherein said porous member is in the form of an insert positioned in at least one channel. 
   
   
       26 . A parallel flow heat exchanger as set forth in  claim 25  wherein said porous insert is positioned at the channel entrance. 
   
   
       27 . A parallel flow heat exchanger of  claim 26  wherein the porous insert is positioned adjacent to the channel entrance. 
   
   
       28 . A parallel flow heat exchanger of  claim 26  wherein the porous insert is positioned inside the channel. 
   
   
       29 . A parallel flow heat exchanger of  claim 20  wherein the porous insert is positioned in the inlet manifold or in direct fluid communication with inlet manifold. 
   
   
       30 . A parallel flow heat exchanger of  claim 20  wherein the porous insert is positioned in the outlet manifold or in direct fluid communication with outlet manifold. 
   
   
       31 . A parallel flow heat exchanger of  claim 20  wherein the porous insert is positioned in the intermediate manifold or in direct fluid communication with intermediate manifold. 
   
   
       32 . The porous insert of  claim 20  wherein said insert is made from a material selected from the group consisting of a metal and a ceramic. 
   
   
       33 . The porous insert of  claim 20  wherein said insert is made from a material selected from the group consisting of sintered metal, compressed metal, metal wool or metal wire. 
   
   
       34 . The porous insert of  claim 20  wherein said insert is positioned longitudinally along the manifold. 
   
   
       35 . The porous insert of  claim 20  wherein there is a gap between said insert and the manifold inner wall surface. 
   
   
       36 . The porous insert of  claim 20  wherein said insert is a composite of at least two different inserts. 
   
   
       37 . The porous insert of  claim 20  wherein said insert cross-section is non-rectangular. 
   
   
       38 . The porous insert of  claim 37  wherein said insert cross-section is a portion of a circle. 
   
   
       39 . The porous insert of  claim 20  wherein said inserts are of variable characteristics between at least two channels. 
   
   
       40 . The insert of  claim 39  wherein the variable characteristics are selected from the group of porosity, depth, insertion depth, and material.