GB2436669A

GB2436669A - Heat exchanger for a rackmount cabinet used in a raised floor installation

Info

Publication number: GB2436669A
Application number: GB0604683A
Authority: GB
Inventors: Edward Reddicliffe
Original assignee: Cannon Technologies Ltd
Current assignee: Cannon Technologies Ltd
Priority date: 2006-03-08
Filing date: 2006-03-08
Publication date: 2007-10-03
Anticipated expiration: 2026-03-08
Also published as: GB0604683D0; GB2436669B

Abstract

A heat exchanger module 1 for use in a raised floor installation 8 comprises a means for cooling a space above the heat exchanger 1 and a slidable attaching means 7 for sliding the heat exchanger 1 below the raised floor 8. The slidable attaching means 7 may slide the heat exchanger 1 from a first position below a rackmount cabinet 2 to a second position 1' below a position adjacent the rackmount cabinet 2. The heat exchanger 1 may be a fan type liquid to air type. The slidable attaching means 7 may be a ball bearing track system or solid bearing slide system. A flange arrangement that may be tapered may be provided on the heat exchanger 1 to seal an output of the heat exchanger 1 to an aperture at the base of the rackmount cabinet 2. The heat exchanger 1 may be connected to a power and fluid source via elastically extendible cables and pipes. The footprint of the rackmount cabinet 2 is not increased, existing wiring and electronic devices do not need changing and the slidable arrangement 7 permits easy servicing of the heat exchanger 1.

Description

I

HEAT EXCHANGER MODULE

The present invention relates to a heat exchanger for a cabinet used in a raised access floor installation.

The advent of large scale telecommunication networks has brought with it the need to locally store large quantities of interconnected telecommunication devices.

These devices have traditionally been installed in spaces comprising rackmount cabinets. Because each of the devices in rackmount cabinets can comprise several connection points and cabinet rooms can be filled with a large number of cabinets, raised access floor systems were designed to facilitate the dynamic reconfiguration of interconnections.

Raised access floor systems are elevated flooring systems which comprise square panels supported by various types of support structures, each panel being of a fixed size. The support structures usually comprise a metal grid supported by short pillars. Typically, each rackmount cabinet contains several pieces of electronic equipment, the heat dissipation characteristics of which vary with the nature of each device. In order to ensure that sensitive and expensive electronic equipment does not overheat, various types of cooling systems have been developed.

The simplest form of heat exchanger module is an array of fans or what is known as a fan tray. Fan trays are sometimes mounted on the sides of cabinets and simply pull hot air out of the enclosure. The major disadvantage with using side-mounted fan tray modules is that, because they extend outwardly beyond the actual footprint of the cabinet, they render the space below them effectively unusable, thereby increasing the effective footprint of the cabinet. Because the footprint of a cabinet is typically the same size as a panel, cabinets can normally be placed immediately adjacent to each other. However, when fan trays are mounted to the side of a cabinet, no such configuration can take place, thereby wasting valuable space. Placing the fan trays at the rear of the cabinet can obstruct cross-cabling between enclosures.

Similarly, mounting the fan trays on the door of the heat exchanger obstructs access to the equipment inside and also complicates the construction of the cabinet itself.

In order to solve the problems associated with side-mounted fan trays, a top-mounted heat exchanger module was developed. The major advantage of this system is that it does not increase the effective footprint of a cabinet. Thus, cabinets can be positioned immediately adjacent to each other, thereby saving valuable floor space.

However, an important disadvantage associated with top-mounted heat exchanger modules is the extra weight which is put on the cabinet, which in many cases is enough to overload cabinets of standard construction. Thus, top-mounted heat exchanger modules require sturdier cabinets which accordingly have higher manufacturing costs.

Also, top-mounted units are not well suited to areas in which there are height restrictions and are very difficult to service because they are physically so high off the ground.

Another significant disadvantage with top-mounting modules has resulted from the emergence of more efficient heat exchanger technology. Because of ever-increasing processing power, electronic devices produce increasing amounts of heat.

Accordingly, more powerful forms of heat exchanger have been developed. The more common and commercially successful of these have been liquid-to-air heat exchanger modules. Although side-mounted liquid-to-air heat exchanger modules suffer the same disadvantages that side-mounted fan tray modules do, top-mounted liquid-to-air modules suffer a further disadvantages in that they are typically heavier than fan trays and also may leak corrosive liquid onto very sensitive and expensive electronic devices positioned below them. Such leaks are likely to happen while the modules are being serviced by a technician because of the awkwardly high position of the heat exchanger module. Also, the pipes and wiring required for the operation of the heat exchanger must be fed up through the cabinet itself, thereby decreasing the amount of usable space in the cabinet.

Accordingly there is a need for a heat exchanger which does not increase the effective footprint of an electronic device cabinet, that does not require a change of existing wiring, that does not necessitate a change in design of an electronics device cabinet and that allows easy access to electronic devices inside the cabinet and to the module itself so that it can be properly serviced.

In order to solve the problems associated with prior art heat exchanger modules, the present invention provides a heat exchanger module arranged for use in a raised access floor installation, the heat exchanger comprises: heat exchanging means for cooling a space substantially above the heat exchanger; and slidable attaching means for slidably attaching the heat exchanger below a section of a raised access floor.

Preferably, the slidable attaching means are operable to slide the heat exchanging means from a first position situated substantially below a rackmount cabinet to a second position substantially below a position adjacent to the rackmount cabinet.

The means for cooling the space substantially above the heat exchanger may be a fan-type heat exchanger.

The means for cooling the space substantially above the heat exchanger may be a liquid-to-air type heat exchanger.

The slidable attaching means for slidably attaching the heat exchanger may be a ball bearing rail track system.

The slidable attaching means for slidably attaching the heat exchanger may be a solid-bearing slide system.

Preferably, the heat exchanger module further comprises: a flange arrangement for sealing, in use, the output of the heat exchanger to the aperture at the base of a rackmount cabinet.

The present invention provides several advantages over the prior art. Because the heat exchanger is housed entirely under the floor, the top surface of the floor can be used for other purposes, allowing more equipment to be housed in a room. Also, there is no contamination of the interior of the rackmount cabinet by hot air in the room in that the floor tiles act as a barrier to such cross-contamination. Airflow into the cabinet is significantly increased as the whole of the cabinet base is available as an input, as opposed to the use of grills or ventilation holes which are needed in top or side mounted heat exchangers. Furthermore, any leakage of fluid will be below any active electronics, and noise and vibration is more effectively isolated from the room area. Maintenance is easily achieved without disruption to active equipment, and variations to other equipment in the room have no impact on the underfloor heat exchangers. In addition, more cabinets can be accommodated in a standard room volume as previously under-utilised space below raised access floor panels can be used. Also, there is greater freedom of design to lay out room plans as each heat exchanger and cabinet share the same single footprint, thereby eliminating the need to consider the dimensions of the heat exchangers when designing room layouts.

An example of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a cross sectional view of a raised floor in which a heat exchanger module according to a first example of the present invention is installed; Figure 2 is a plan view showing a matrix of raised floor tiles under which a heat exchanger module according to the present invention is installed; Figure 3 is a perspective view of a flange assembly for the heat exchange module according to the present invention; Figure 4 is a top view of a flange assembly for the heat exchanger module according to the present invention; and Figure 5 is a cross sectional view of a heat exchanger module according to a second example of the present invention.

In reference to Figure 1 and Figure 2, the present invention comprises a heat exchanger 1 and slidable attaching means 7 for slidably attaching the heat exchanger 1 underneath a section of raised access floor 8. The heat exchanger may also comprise fluid pipes (not shown) for cooling fluid. The raised floor 8 comprises a plurality of raised floor panels 4 supported above an actual floor 6 by a plurality of support pillars 3. The floor panels 4 and support pillars 3 can be made of a wide variety of materials. The raised access floor 8 is arranged so that any raised floor panel 4 can be replaced with a rackmount cabinet 2. The rackmount cabinet 2 may contain a plurality of electronic devices.

When the heat exchanger 1 is in an operating position, it is located substantially beneath the rackmount cabinet 2. In this position, the heat exchanger 1 is operable to cool the space directly above it (i.e. the interior of the rackmount cabinet 2). The heat exchanger is connected to a power source and fluid source via elastically extendible power cables and fluid pipes 5, the power source being located underneath the raised access floor 8 and preferably on the actual floor 6.

When the heat exchanger 1 needs to be serviced, it can be slid into a servicing position by way of the slidable attaching means 7'. The slidable attaching means 7 in this example consists of a ball bearing rail track system but could be any other suitable device for slidably attaching the heat exchanger 1 to the raised access floor 8.

When the heat exchanger I is in its servicing position, it is situated substantially beneath a position adjacent to the footprint of the rackmount cabinet 2, the elastically extendible power cables and fluid pipes 5 still being attached thereto or, alternatively, released by way of quick release couplings. When in this position, the heat exchanger 1' can be easily accessed by removing at least one raised floor panel 4 adjacent to the rackmount cabinet.

With reference to Figure 3, the output of the heat exchanger 1 is hermetically attached to the aperture at the base of the rackmount cabinet 2 by way of a sliding flange arrangement. A three sided receiving section Ills attached directly below the base of the cabinet 2 and an upward flange portion 12 is attached to the output of the heat exchanger 1 and is slidably engageable with the three sided receiving section 11 so as to form a hermetic seal between the heat exchanger 1 and the aperture at the base of the rackmount cabinet 2.

With reference to Figure 4, the sides of both the three sided receiving section 11 and the upward flange portion 12 are inwardly tapered such that applying pressure in the direction of insertion will increase the integrity of the seal.

With reference to Figure 5, a second example of the present invention may comprise floor mounted slidable attachment means 12 which slidably attached the heat exchanger 1 to the actual floor 6 or to a rail system embedded in the actual floor 6. In this example, the heat exchanger us attached to the slidable attachment means 2 by way of a plurality of articulated members (13'; 13). In a extended position, the articulated members 13 maintain the heat exchanger 1 in a raised position. The heat exchanger 1 may be in a raised position substantially beneath a position adjacent to the footprint of the rackmount cabinet 2, thereby facilitating servicing of the heat exchanger 1. After servicing, the heat exchanger 1 can be lowered by folding the articulated members 13' into a folded position. When lowered, the heat exchanger 1 can be slid to a position substantially beneath the footprint of the rackmount cabinet 2 and then lifted, using the articulated members 13 into a position directly below the aperture of the base of the rackmount cabinet 2. The articulated members (13; 13') can be actuated by various means, including sleeved cable systems.

A flange 14 is attached to the aperture at the bottom of the rackmount cabinet 2 in order to ensure a hermetic seal between the output of the heat exchanger 1 and the aperture at the base of the rackmount cabinet 2. The flange can also be tapered in such a way that forcing the heat exchanger 1 upwards increases the integrity of the hermetic seal.

The slidable attaching means 7 of either the first or the second examples may comprise locking means for locking the heat exchanger in one of either the operating position or the servicing position. Whilst not shown, the slidable attaching means may also comprise driving means for driving the heat exchanger I from one position to the other. These may include telescopic driving means, pulley systems or any other suitable solid slide mechanism.

Claims

CLAIMS

1. A heat exchanger module arranged for use in a raised access floor installation, the heat exchanger comprising: heat exchanging means for cooling a space substantially above the heat exchanger; and slidable attaching means for slidably attaching the heat exchanger below a section of a raised access floor.

2. The heat exchanger module of claim 1, wherein the slidable attaching means are operable to slide the heat exchanging means from a first position situated substantially below a rackmount cabinet to a second position substantially below a position adjacent to the rackmount cabinet.

3. The heat exchanger module of either of claims I or 2, wherein the means for cooling the space substantially above the heat exchanger is a fan-type heat exchanger.

4. The heat exchanger module of either of claims 1 or 2, wherein the means for cooling the space substantially above the heat exchanger is a liquid-to-air type heat exchanger.

5. The heat exchanger module of any of the preceding claims, wherein the slidable attaching means for slidably attaching the heat exchanger is a ball bearing rail track system.

6. The heat exchanger module of any of claims 1 to 4, wherein the slidable attaching means for slidably attaching the heat exchanger is a solid-bearing slide system.

7. The heat exchanger module of any of the preceding claims, further comprising: a flange arrangement for sealing, in use, an output of the heat exchanger to an aperture at the base of a rackmount cabinet.