AU646283B2

AU646283B2 - Thermally controlled equipment housing

Info

Publication number: AU646283B2
Application number: AU83401/91A
Authority: AU
Inventors: Ian Henry Browning; Samuel Dean
Original assignee: Alcatel Australia Ltd
Current assignee: Nokia Services Ltd
Priority date: 1990-09-05
Filing date: 1991-08-23
Publication date: 1994-02-17
Anticipated expiration: 2011-08-23
Also published as: AU8340191A

Description

r, I P/00/011 28/5/91 R~egulation 3.2 6 4

AUSTRALIA

Patents Act 1990 0 0004 0000 000 4 4 0 04 4 4 qg

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "THERMALLY CONTROLLED EQUIPMENT HOUSING" The following statement is a fll description of this invention, including the best mecthodl of performing it known to uts:- 2 This invention relates to a housing for electronic equipment, particularly, though not exclusively, telecomunications equipment such as rurai exchanges and remote integrated multiplexers, which include heat producing active components. The avention is particularly concerned with the cooling of such a housing.

In known housings of the aforementioned type, cooling is achieved by natural convection. A disadvantage of this simple method of cooling is that the equipment housed is exposed to hazards such as dust, moisture and insects carried on the cooling air.

It is an object of the present invention to provide a housing to house and protect electronic equipment in a harsh environment, and to maintain the housed equipment within acceptable temperature limits regardless of the outside temperatare.

According to the invention there is provided a housing for electronic equipment, said housing comprising an outer cabinet having a top wall and a bottom wall joined ooo o by two side walls, a rear wall and a substantially air-tight front door panel, said door o 15 panel being common to an inner cabinet supported within said outer cabinet, and in which said electronic equipment is mounted, said inner cab-net comprising a further 9949 top wall and a bottom wall joined by two side walls, and a rear wall, wherein said S4 4 housing includes an air cooling arrangement for cooling air in the inner cabinet, said cooling arrangement comprising a heat exchanger means in the form of a corrugated panel interposed between a first and a second flat panel such that peaks and troughs of the corrugations of the corrugated panel are respectively contiguous with said first and said second flat panels to form a first array and a second array of adjacent open ended tubes extending longitudinally between the top and bottom walls of the inner cabinet, open ends at one end of the first array of tubes communicating via cowling means with the interior of said inner cabinet, and open ends of one end of the second array of tubes communicating via cowling means with air external to said outer cabinet, and wherein said external air is impelled by at least one controllable first fan 6 means mounted on or in said outer cabinet, through said second array of tubes and exhausted via ventilation means, while air within said inner cabinet is impelled by at least one second controllable fan means past said electronic equipment and through said first array of tubes thereby transferring any heat therefrom to the impelled air in the second array of tubes.

Preferably, the first flat panel contiguous with parts of the corrugated panel is formed by the rear wall of said inner cabinet.

Preferably, the side walls of the inner and outer cabinets are common.

77 3 In order that the invention may be readily understood, an embodiment thereof will now be described in relation to the drawings, in which: Figure I is a front view of the housing according to the present invention.

Figure 2 is a side view of the housing shown in Figure 1.

Figure 3 is a sectional view of part of the heat exchanger.

-,gure 4 is a block schematic of a fan control system for controlling the fans incorporated in the housing of the present invention.

Referring to Figures 1 3, the housing comprises a rectangular box-shaped outer cabinet 1 having a front door panel 2, a rear panel 3, a top panel 4, a bottom panel 5 and two side panels 6 and 7. Within outer cabinet 1 is an inner cabinet 8 comprising a top wall 9, a bottom wall 10 and a rear wall 11. Front door panel 2 and side walls 6 and 7 are common to both cabinets. Within cabinet 8 there are arranged two fan supports 12 and 13 each respectively supporting an array of two mains powered fans, 15, 16 and 17, 18 for blowing air past rack mounted electronic equipment (not shown) mounted within cabinet 8. Further mains powered fans 19 and 20 are mounted in the space between top walls 4 and 9 for drawing in external air via a filtered vent 21. Between the rear wall 3 of the outer crbinet and rear wall 11 of the inner cabinet is arranged a corrugated panel 22 of substantially the same width as the said rear walls, whose peaks and troughs are respectively contiguous with panels 3 K and 11 to form to juxtaposed arrays of vertical tubes A and B. Array A commur nicates with the interior of cabinet 8 via cowling 9, and array B communicates with

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j vent 21.

It will be understood that the number and configuration of the fans will vary depending on the cabinet size.

In operation, cooling air is drawn in via filtered vent 21 by fans 19 and 20 and impelled through the tubes of array B, and exhausted at vent 21b. Warm air within cabinet 8, produced by power dissipation of the electronic equipment, is impelled by controlled fans 15 to 18 past the equipment (not shown) into the tubes of array A and circulated through a vent (not shown) in bottom wall 10. Heat from the air within cabinet 8 is transferred across the corrugated panel 22 to the cooler air passing over the surface of the tubes of array B.

Referring to Figure 4, the control system comprises a processor FIU an input of which is coupled an internal temperature sensor. The processor is programmed to activate predetermined combinations of fans to maintain the temperature within

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cabinet 8 below a predetermined threshold temperature. To provide uniform cooling of the equipment within cabinet 8, fan operation is rotated by the processor.

In the event of the relative humidity within cabinet 8 approaching condensation level, a humidity sensor coupled to a further input of processor FLU causes the operating temperature threshold to be raised by the processor to reduce the relative humidity. In this connection, a small heating element may be included within cabinet 8 and controlled by the processor.

In the event of unusual conditions such as excessive temperature, fan failure (sensed by a change of speed), mains power failure, impending filter clogging, or system shut-down (when the auxiliary battery voltage drops below operational level), additional sensors coupled to further inputs of processor FIU sense these conditions and the processor provides alarm signal conditions which are communicated to a remote central control station.

While the present invention has been described with regard to many particulars, it will be understood that equivalents may be readily substituted without departing from the scope of the invention.

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Claims

1. A housing for electronic equipment, said housing comprising an outer cabinet having a top wall and a bottom wall joined by two side walls, a rear wall and a front door panel, said door panel being common to an inner cabinet supported within said outer cabinet, the front door panel forming a substantially air-tight door on the inner cabinet, and in which said electronic equipment is mounted, said inner cabinet comprising a further top wall and a bottom wall joined by two side walls, and a rear wall, the inner cabinet being substantially air-tight, wherein said housing includes an air cooling arrangement for cooling air in the inner cabinet, said cooling arrangement comprising a heat exchanger means in the form of a corrugated panel interposed between a first and a second flat panel such that peaks and troughs of the corrugations of the corrugated panel are respectively contiguous with said first and said second flat panels to form a first array and a second array of adjacent open ended tubes extending longitudinally between the top and bottom walls of the inner cabinet, open ends at one end of the first array of tubes communicating via cowling means with the interior of said inner cabinet, and open ends of one end of the second array of tubes communicating via cowling means with air external to said outer cabinet, and wherein said external air is impelled by at least one controllable first fan means mounted on or in said outer cabinet, through said second array of tubes and exhausted via ventilation means, while air within said inner cabinet is impelled by at least one second controllable fan means past said electronic equipment and through said first array of tubes thereby transferring any heat therefrom to the impelled air in the second array of tubes.

2. A housing as claimed in claim 1, wherein said first flat panel contiguous with parts of said corrugated panel is formed by the rear wall of ssid inner cabinet.

3. A housing as claimed in claim 1 or 2, wherein the side walls of the inner and outer cabinet are common.

4. A housing as claimed in any one of claims 1 3, wherein said second controllable fan means comprises a plurality of controllable fans supported on fan support means mounted in said inner cabinet, and arranged to blow air past said electronic equipment mounted therein. r Oe A housing as claimed in any one of the preceding claims, wherein said at least one controllable first fan means comprises at least one controllable fan mounted within space defined by top wall of said outer cabinet and said top wall of said inner cabinet.

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6. A housing as claimed in any one of the preceding claims, wherein the external air impelled by said at least one controllable first fan means is drawn through a fil- tered vent means in the outer cabinet.

7. A housing as claimed in any one of the preceding claims wherein said first controllable fan means and the said second controllable fan means are controlled by a programmable control unit means for controlling the operation of said fan means in accordance with predetermined parameters sensed by a plurality of sensing means coupled to said control unit.

8. A housing as claimed in claim 7, wherein said parameters include internal and external temperature sensed by thermometer means and relative humidity sensed by relative humidity sensor means.

9. A housing as claimed in claim 8, wherein the programmable control unit is programmed to activate predetermined combinations of said fans to maintain the temperature within said inner cabinet below a predetermined operating temperature threshold.

A housing as claimed in claim 9, wherein the predetermined operating tem- perature threshold is raised by said control unit when relative humidity sensed by relative humidity sensing means approaches a predetermined level.

11. A housing as claimed in claim 10, wherein heating means within said inner cabinet is activated by said control unit when relative humidity approaches said pre- determined level.

12. A housing as claimed in any one of claims 7 to 11, wherein said sensing means 4includes means for generating alarm signals in the event of predetermined alarm conditions.

13. A housing as claimed in claim 12, wherein said alarm signals are coupled to a remote central control station.

14. A housing substantially as herein described with reference to Figures 1 4 of the accompanying drawings. A housing as claimed in any one of the preceding claims, wherein said elec- tronic equipment includes telecommunications equipment.

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16. A housing as claimed in claim 15, wherein said telecommunications equipment is rural exchange equipment or remote integrated multiplexer equipment. DATED THIS THIRD DAY OF JUNE 1991 ALCATEL AUSTRALIA LIMITED I~ I ABSTRACT This invention relates to a housing to house electronic equipment, particularly telecommunications equipment, in a harsh environment, and to the cooling of such a housing to maintain the housed equipment within acceptable temperature limits re- gardless of external temperature. The invention discloses a housing arrangement comprising a sealed inner equipment cabinet within an outer cabinet Fans (15, 16, 17 and 18) force air through the equipment and past a heat exchange surface (22) where it is transferred to cooler external air drawn into the outer cabinet by further fan means (19, and blown past the opposite heat exchange surface and exhausted through a vent (21b). Fan operation is controlled by a processor. An advantage of this arrangement is that the equipment is isolated from the external air and therefore protected from dust, moisture and insects. (Figures 1 and 2). ,i. :i :i