High efficiency cascade-style heat exchanger

Abstract

A heat exchanger used for wind tunnel temperature control applications. The heat exchanger is a finned tube design with each tube aligned perpendicular to the wind tunnel flow direction but with the tube bundle aligned at an oblique angle to flow direction for increased surface area. Tube fins may be aligned with the bulk flow direction. The heat exchanger is built in modules with horizontal splitter plates separating each tube bundle. The benefit of this heat exchanger design for wind tunnel applications is the combination of low pressure loss and favorable heat transfer performance in a compact design, while maintaining flow quality consistent with stringent test requirements.

1 . A heat exchanger for use in a windtunnel with a direction of bulk air flow, comprising:
 a frame for mounting one or more tube modules;   one or more tube modules, each tube module comprising a tube bundle with a front face and one or more fins, each tube bundle comprising a plurality of parallel hollow tubes aligned across the direction of bulk air flow, wherein a coolant or fluid flows through the hollow tubes, and further wherein said fins are attached to the tubes;   wherein the front face of each tube module is angled with respect to the direction of bulk air flow.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the front face of each tube module is angled at an oblique angle with respect to the direction of bulk air flow. 
     
     
         3 . The heat exchanger of  claim 2 , wherein the oblique angle is 30 degrees. 
     
     
         4 . The heat exchanger of  claim 1 , wherein multiple modules are stacked vertically in the frame. 
     
     
         5 . The heat exchanger of  claim 1 , wherein six tube modules are stacked vertically in the frame. 
     
     
         6 . The heat exchanger of  claim 4 , further comprising a splitter plate located between adjacent tube modules, each said splitter plate aligned parallel to the direction of bulk air flow. 
     
     
         7 . The heat exchanger of  claim 1 , each tube module further comprising one or more fluid inlets and one or more fluid outlets. 
     
     
         8 . The heat exchanger of  claim 1 , wherein heat transfer from said tubes to said fins cools the fins, which provides convective cooling to the air flow passing over the fins. 
     
     
         9 . The heat exchanger of  claim 1 , wherein the fins are aligned with the direction of bulk air flow.