LOCKING ORIFICE RETAINING NUT
An inlet manifold for use with a heat exchange device such as a cold plate in which the manifold includes a main passage for transferring liquid. The main passage includes a seat sized to hold an orifice plate for restricting the transfer of liquid to a flow suitable to produce a pressure drop. An orifice plate retaining element contacts the orifice plate to maintain the orifice plate on the seat, and has a locking element to prevent unlocking during use.
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This invention was made with government support under NNJ06TA25C awarded by NASA. The government has certain rights in the invention.
BACKGROUNDHeat exchangers are conventionally used to heat devices that require heat or cool devices that produce heat that needs to be removed. One example of a heat exchanger is known as a cold plate, which is used, for example, to cool electronic units that produce heat while being operated. The heat needs to be removed to permit the electronic components to continue functioning.
One concern about the use of cold plates is that when orifices are used to control the pressure drop or flow rate, the orifices have been retained in bolted housings that require seals. This introduces potential leak points into the system. Often it is necessary to adjust or control the pressure drop or flow rate specifically for a particular end use, so the cold plate cannot be used without a method of making that adjustment or control. If the cold plate is intended for use in extreme environments, such as in outer space, the seals are particularly vulnerable and the potential for leakage prohibits their use.
An alternative way to control the pressure drop or flow rate in cold plates is needed to permit use of cold plates in extreme environments.
SUMMARYThe present invention is a device for adjusting fluid flow in cold plates and other fluid flow heat exchangers to obtain a desired pressure drop without the use of seals. The device includes an orifice that provides the desired fluid flow, thus controlling coolant pressure drop inside a cold plate. Different orifices are employed until the one is found that has the appropriate internal diameter to provide the desired pressure drop. During testing, the orifice is secured with a non-locking orifice nut. Once correct orifice size is determined, the orifice is secured using a nut with a locking element.
Orifice plate 37, shown alone in
Orifice retention bore 29 has threads 29A on its inner wall to engage external threads 39A on orifice retaining nut 39. A smaller diameter portion 41 extends from retaining nut 39 into a reduced diameter portion of retention bore 29 and holds in place orifice plate 37. Orifice plate 37 and retaining nut 39 may be made from any solid material. Stainless steel has been shown to be effective for both elements.
Orifice retaining nut 39 also includes locking strip 43. One locking strip that has been effective is a KEL-F® PCTFE strip as defined in AMS 3650, which is standard for locking screws and bolts. KEL F® is a 3M registered trademark for a polychlorotrifluoroethylene polymer and has an operating temperature range of −320° F. (−196° C.) to +390° F. (199° C.). A slot is cut in threaded portion 39A of locking nut 39, typically about 0.020 inches (0.08 mm) and filled with a strip of the polymer. Flared inlet 40A of center bore 40 guides fluid from inlet passage 27.
During assembly of cold plate 11, orifice plates 37 having different sized orifices 37A are put in inlet manifolds 15A and 15B, as shown with manifold 15A in
The cold plate system of this invention permits controlled cooling of individual electronic units base upon the needs of the unit through selection of the appropriate orifice diameter determined through pre-installation testing. After final installation, the electronics are now protected from heat generated during operation of the electronic components.
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Claims
1. An inlet manifold assembly, the assembly comprising:
- an inlet;
- an outlet;
- a main passage for transferring liquid from the inlet to the outlet, the main passage having a seat;
- an orifice plate in the main passage seat for controlling flow of liquid the main passage; and
- an orifice plate retaining element contacting the orifice plate to maintain the orifice plate on the seat.
2. The assembly of claim 1, wherein the seat is located in the main passage at a reduced diameter sized to hold the orifice plate.
3. The assembly of claim 1, wherein the orifice plate retaining element and the main passage have mating threads for locating the retaining element.
4. The assembly of claim 3, wherein locking element comprises a strip of polychlorotrifluoroethylene in a strip cut in a threaded portion of the retaining element and extends out from the strip to engage the threads on the main passage.
5. The assembly of claim 1, wherein the orifice plate and the retaining element are made from stainless steel.
6. The assembly of claim 1, wherein the orifice plate has a centrally located orifice; and the retaining element includes a central bore that is aligned with the main passage and the orifice.
7. A cold plate device for use to cool objects, the device comprising:
- a plate member having a first and second side;
- a cooling tube loop mounted on the first side of the plate member;
- an inlet manifold having an inlet and an outlet for transferring cooling fluid to the cooling tube from the inlet to the outlet, the at least one inlet manifold having a seat located therein;
- an orifice plate positioned on the seat in the inlet manifold for controlling flow of cooling fluid into the cooling tube loop;
- a retaining element mounted in the inlet manifold for holding the orifice plate in fixed position; and
- an outlet manifold for transferring cooling fluid out of the cooling tube loop.
8. The device of claim 7, wherein the seat is located in a main passage of the inlet manifold at a reduced diameter sized to hold the orifice plate.
9. The device of claim 7, wherein the orifice plate has a centrally located orifice; and the retaining element includes a central bore that is aligned with the main passage and the orifice.
10. The device of claim 7, wherein the orifice plate retaining element and the main passage have mating threads for locating the retaining element.
11. The device of claim 10, wherein the retaining element including a locking element preventing removal of the retaining element.
12. The device of claim 11, wherein locking element comprises a strip of polychlorotrifluoroethylene in a strip cut in the threaded portion of the retaining element and extending out from the strip to engage the threads on the main passage.
13. The device of claim 7, wherein the orifice plate and the retaining element are made from stainless steel.
14. A method for selecting the flow rate of cooling fluids in a cold plate having a plate member having a first and second side and a cooling tube loop mounted on the first side, an inlet manifold transferring cooling fluid to the cooling tube loop and having a seat, the method comprising:
- mounting an orifice plate on the seat in the inlet manifold to regulate the flow of cooling fluid into the at least one cooling tube;
- holding the orifice plate with a retaining element mounted in the inlet manifold in fixed position; and
- transferring cooling fluid through the cooling loop.
15. The method of claim 14, wherein the seat is located in the main passage at a reduced diameter sized to hold the orifice plate.
16. The method of claim 14, wherein the orifice plate is selected by testing a plurality of orifice plates having different bore sizes, the plurality of orifice plates being held in place for testing with a temporary retaining element.
17. The method of claim 14, wherein the orifice plate retaining element and the main passage have mating threads for locating the retaining element.
18. The method of claim 17, wherein the retaining element includes a locking element preventing removal of the retaining element.
19. The method of claim 18, wherein locking element comprises a strip of polychlorotrifluoroethylene in a strip cut in the threaded portion of the retaining element and extending out from the strip to engage the threads on the main passage.
20. The method of claim 14, wherein the orifice plate and the retaining element are made from stainless steel.
Type: Application
Filed: Jun 5, 2012
Publication Date: Dec 5, 2013
Applicant: Hamilton Sundstrand Space Systems International, Inc. (Windsor Locks, CT)
Inventors: Michael Mowry (Castaic, CA), David Blue (Los Angeles, CA), Kevin McCarthy (Simi Valley, CA), Hector Ortiz-Perez (Simi Valley, CA)
Application Number: 13/488,767
International Classification: F28F 3/12 (20060101); F28F 9/02 (20060101);