HEAT DISTRIBUTION FOR AN ENCLOSURE

Technical Field

This invention relates to heat generated by an electronic control assembly contained within a totally closed enclosure. Heat is distributed and dissipated so as to provide effective cooling of the heat generating components.

Background Art

Auxiliary equipment being driven by power equipment such a gas turbine engines require controls to functionally control and monitor the operation of the auxiliary equipment and the power source. Such controls are conventionally housed within an enclosure. Conventionally, these enclosures are open to atmosphere by vents and cooling openings. It has been normal practice to utilize fans to draw atmospheric air into the enclosures, circulate the air through the enclosure and cool the components within. The application of such enclosures in severe applications, such as, in the desert and near salt containing bodies of water increases the possibility of contaminates entering the enclosures. The results being reduced life of the equipment within the enclosure. Attempts have been made to install filters in such hazardous application; however, after a given period of time the filters become clogged requiring replacement and/or cleaning. Failure to prevent such clogging will either reduce the cooling effectiveness or again result in the containments entering the

enclosure and causing premature failure of the equipment within the enclosure.

The present invention is directed to overcome one or more of the problems as set forth above.

Disclosure of the Invention

In one aspect of the invention an enclosure is comprised of a plurality of structural members, a cavity formed within the plurality of structural members and a rack positioned within the cavity. A heat generating device is positioned within the rack and forms a heat generating portion within the cavity and the remainder of the cavity generally forms a heat absorbing portion. A fan mechanism is operatively interposed the rack and the heat generating devices. During operation of the fan mechanism, a circulation of a cooling media between the heat generating portion and the heat absorbing portion within the cavity occur.

Brief Description of the Drawings

FIG. 1 is a pictorial view of an enclosure embodying the present invention;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1; FIG. 4 is an enlarged exploded view of a rack embodying the present invention; and

FIG. 5 is an electrical diagram for a control circuit.

Best Mode for Carrying Out the Invention

Referring to FIGS. 1, 2 and 3, an enclosure 10 is made of a material having a heat absorbing and a heat dissipating characteristic, which in this application is steel. The enclosure 10, during operation defines an outside heat dissipating surface 12 and an inside heat absorbing surface 14. The enclosure 10, being formed by a plurality of structural members 16, includes a generally rectangular back portion 18 a pair of end portions 20 being sealingly attached to the back portion 18 at an end 22 thereof. A top portion 24 is sealingly attached to the back portion 18 and the pair of end portions 20. A bottom portion 26 is sealingly attached to the back portion 18 and the pair of end portions 20. A front portion 28 includes a door 30, which in this application includes a pair of doors 32. The doors are pivotally mounted to the front portion 28 and are sealed therewith. The pair of doors 32 have an open position, not shown, and a close position 36. In the close position 36, the pair of doors 32 are in sealing engagement with the front portion 28 and form a generally sealed cavity 38 within the enclosure 10. However, as an alternative the pair of doors 32 could replace the front portion 28, be pivotally mounted to the pair of end portions 20 and would be in sealing engagement with the top portion 24, the bottom portion 26 and the pair of end portions 20. Attached to the inside of the enclosure 10 is a plurality of terminal strips 40. The plurality of terminal strips 40 are removably attached to the back portion 18 and the end portions 20 in a conventional manner. Each of the strips 40 are

systematically positioned within the enclosure to provide a preestablished spacing, designated by the arrows 42, between a plurality of electrical modules 44. Examples of such modules 44 which extend into the cavity 38 include voltage regulators, terminal blocks, relays, etc. Further attached to the enclosure 10 is a plurality of racks 46 having additional electrical modules 44 attached thereto. In this application the racks 46 are positioned above the plurality of terminal strips 40 near the top of the enclosure 10. Positioned within a portion of the racks 46 and extending into the cavity 38 is a programmable logic controller section (PLC) 48 and positioned within another portion of the racks 46 is a line synchronization module section (LSM) 52. Each of the racks 46 includes a first member 58, a pair of side members 60 being attached to the front member 58, a top member 62 positioned in contacting relationship above the front member 58 and the pair of side members 60 and a bottom member 64 positioned in contacting relationship below the front member 58 and the pair of side members 60. In this application the side member 60 are made from a metallic impervious sheet, the top member 62 is made from a metallic sheet and has a plurality of openings 66 defined therein being spaced a preestablished distance one from another. And, the bottom member 64 is made from a metallic sheet having a plurality of passages 68 therein. The passages 68 can be constructed by making opening or holes or louvers. Attached to the top member 62 and relatively positioned about each of the plurality of openings 66 is a variable speed fan mechanism 70.

A portion of the electrical modules 44 are heat generating devices 80. Thus, the cavity 38 can generally be divided into a heat generating portion

82 and a heat absorbing portion 84. In this application, the heat generating portion 82 is generally positioned near the top of the enclosure 10 and the heat absorbing portion 84 is generally positioned below the heat generating portion 82. As an alternative, the heat generating portion 82 could be positioned at any position within the cavity 38 such as near the bottom, or in any one of a large variety of positions too numerous to describe. Likewise, the heat absorbing portion 84 would be position in a location of the cavity 38 away from or between the heat generating devices 80. For example, the programmable logic controller section (PLC) 48 and the line synchronization module section (LSM) 52 are examples of the electrical modules 44 positioned within the heat generating portion 82. Examples of the heat absorbing portion 84 would be the spacing 42 between the terminal strips 40, the pair of doors 32 and the top portion 24.

The fan mechanisms 70 are thermostatically controlled. The control circuit 90 is best shown in FIG. 5 and is positioned within the cavity 38. The circuit 90 includes a power source 92 being electrically connected to one of the terminal blocks 44 and having a circuit breaker 94 therebetween, a temperature sensing device 96 electrically interposed the terminal block 44 and the fan mechanisms 70. The circuit 90 is completed by the other side of the fan mechanisms 70 being electrically connected to the power source 92. The temperature sensing device 96 can be conditioned to either fully actuated the fan mechanisms 70 or to modulate the actuation of the fan mechanisms 70 depending on the actual temperature within the cavity 38.

industrial Applicability

In operation, the enclosure 10 is positioned in contacting relationship with the external environment and the outside heat dissipating surface 12 dissipates heat to the external environment as the inside heat absorbing surface absorbs heat from the air, in this application but could be any suitable cooling media, being circulated around the heat generating devices 80. The fan mechanisms 70 which are attached to the top member 62 draw air from within the cavity 38 through the passages 68 in the bottom member 64, along and around the programmable logic controller section 48 and the line synchronization module section 52, thus, absorbing heat from the heat generating devices 80 within the heat generating portion 82 of the cavity 38. The air is thus passed through the fan mechanisms 70 and circulated to the heat absorbing portion 84 of the cavity 38. The inside heat absorbing surface 14 of the enclosure 10 absorbs the heat and the heat is transmitted through the material of which the enclosure 10 is made to the outside heat dissipating surface 12 of the enclosure 10 wherein the heat is absorbed into the external environment.

Thus, the internal environment within the cavity 38 within the enclosure 10 is generally sealed from the external environment in which the enclosure 10 is positioned. This results in the external environment being isolated from the internal environment within the enclosure 10 or cavity 38. The end result being that the components within the enclosure 10 are protected from the external environment contaminates, such as sand, salt and dirt.