Impingement cooled heat sink with low pressure drop
Two embodiments of a heat exchanger assembly for cooling an electronic device are shown respectively in FIGS. 1 and 3 and each comprises a housing, a plurality of high fins, a plurality of low fins, a nozzle plate, an inlet, at least one outlet, a primary nozzle, and a plurality of secondary nozzles. In the first embodiment shown in FIG. 1, the housing and the nozzle plate are circular in shape. In the second embodiment shown in FIG. 3, the housing and the nozzle plate are rectangular in shape. Both embodiments include a plurality of secondary nozzles that are aligned outwardly of the primary nozzle and the center axis of the nozzle plate. The secondary nozzles direct the flow of the cooling liquid outwardly of the primary nozzle from the center thus creating an overall system pressure drop lower than that of other assemblies without a plurality of secondary nozzles.
1. A heat exchanger for cooling an electronic device comprising;
a housing having a center and a top and a bottom for engaging said electronic device,
a plurality of fins extending upwardly from said bottom to upper extremities and extending from and spaced from center,
a nozzle plate in said housing comprising an upper surface and a lower surface and extending across said center and above said fins and below said top to define a fin chamber below and a fluid chamber above,
an inlet into said housing at said center for supplying the cooling fluid to said fluid chamber and said nozzle plate,
a primary nozzle for delivering the cooling fluid from said inlet and through said nozzle plate to said fin chamber for flow from said center between said fins,
at least one outlet disposed outwardly of said fins for receiving the cooling fluid from said fins, and
a plurality of secondary nozzles in said nozzle plate and disposed outwardly of said primary nozzle from said center for directing the cooling fluid into said fin chamber outwardly of said primary nozzle from said center;
wherein said center includes a center axis extending perpendicularly to said upper surface and said lower surface of said nozzle plate;
wherein said primary nozzle is elongated and extends through said center axis of said nozzle plate; and
wherein said primary nozzle includes converging side walls and end walls extending from said inlet and through said nozzle plate and defines a secondary slot in each of said side walls and positioned below said housing and above said nozzle plate for delivering the cooling fluid into said fluid chamber.
2. An assembly as set forth in claim 1 wherein said secondary nozzles are disposed in a pattern of rows parallel to said side walls of said primary nozzle.
3. An assembly as set forth in claim 2 wherein said openings at said lower surface of said nozzle plate of said secondary nozzles define respective equal areas.
4. An assembly as set forth in claim 2 wherein said openings at said lower surface of said nozzle plate of said secondary nozzles define respective areas that vary from secondary nozzle to secondary nozzle.
5. An assembly as set forth in claim 2 including a plurality tertiary nozzles disposed in a pattern of rows outwardly of said rows of said secondary nozzles and parallel to said rows of said secondary nozzles and said elongated primary nozzle for directing the cooling fluid into said fin chamber outwardly of said secondary nozzles and said primary nozzle and said center.