Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K7/00—Constructional details common to different types of electric apparatus
  • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
  • H05K7/20009—Modifications to facilitate cooling, ventilating, or heating using a gaseous coolant in electronic enclosures

Definitions

• the present invention relates to an arrangement for a cooling system for cooling telecommunications equipment installed in rack cabinets positioned one after the other comprising a duct section for each rack cabinet situated 5 beneath it and so arranged for the purpose of cooling the equipment inside the rack cabinet as to direct one or more jets of cool air upwards along the front wall of the rack cabinet, which is executed with openings or similar through which the cooling air can reach the aforementioned 10 equipment, in conjunction with which duct sections contained in the system are connected together to form a duct attached at one of its ends to a cool air unit.
• the object of the present invention is to make available an arrangement for a cooling system of the kind referred to by way of introduction, by means of which the wishes referred to above relating to the power requirement and the losses of the system and the accessibility for service personnel are satisfied.
• This is achieved in accordance with the invention in that the duct section is so arranged as to support the rack cabinet at four support points positioned in pairs in an area around the respective ends of the duct section, in conjunction with which the walls of the duct section in the aforementioned area are reinforced in order to withstand the load of the rack cabinet, which means that the duct section exhibits a smaller flow cross- section in the aforementioned end areas than in a central area situated between the end areas, that a gentle transition is provided between the central area and the end areas in order to prevent the occurrence of turbulence at the aforementioned transitions, and that the front area of the duct section lies in the same plane as the front wall of the rack cabinet, and that a number of upward-facing gills is arranged in the aforementioned central
• FIG. 1 shows a schematic perspective view of a cool air unit which communicates via a distribution box with a duct system in accordance with the invention for cooling telecommunications equipment installed in a rack.
• Fig. 2 shows a section through a cooling duct in accordance with the invention, and
• Fig. 3 shows a perspective view of a flap included in the duct section, viewed from the rear.
• the designation 1 is used in the drawing in respect of a cool air unit, which is intended to supply cooled air for the cooling of telecommunications equipment installed in a number of rack cabinets 2.
• the cool air unit 1 communicates for this purpose via a distribution box 3 with a cooling duct, in which a number of duct sections 4 are included.
• the number of duct sections is the same as the number of racks, and each duct section 4 supports a rack 2.
• Room air, indicated by an arrow 5 in Fig. 1 is taken into the cool air unit 1 via an air inlet la, is cooled in the cool air unit 1, and arrives via the distribution box 3 in the cool air duct formed from duct sections 4.
• each duct section 4 Arranged on the front surface of each duct section 4, which lies in the same plane as the front surface 2a of the corresponding rack cabinet 2, is a number of upwardly open gills 4al arranged to produce a corresponding number of upward-facing jets of cold air, two of which jets are indicated by means of arrows 6 in Fig. 1.
• the respective front walls 2a of the rack cabinets 2 consist of a mesh-like air-permeable material, so that the jets of cool air will flow, in accordance with the fundamental principles of air flow, along the front wall 2a and in through the mesh material in order to cool the telecommunications equipment within.
• the heated cool air exits from the rack cabinets 2 via valve openings 2b arranged at the top of the cabinets.
• the cool air unit 1 is so arranged in this case as to produce an excess pressure inside the cooling duct formed from the duct segments 4, which cooling duct is adapted to the cooling duct in such a way that the static pressure is approximately the same in the whole duct.
• a guide value for the static pressure is 80 Pascal.
• a duct section 4 in accordance with the invention is now described in more detail with reference to Fig. 2.
• the duct section which is preferably made of sheet metal, is in the form of a parallelepipedic tube, the length and width dimensions of which are determined respectively by the width and depth dimensions of the rack cabinet.
• the duct section is provided with identically formed support points 4bl and 4cl on the top and bottom surfaces 4b and 4c of the duct section.
• the support points are positioned in pairs in areas 4d, 4e around the ends of the duct section, as can be appreciated from Fig. 2.
• the rack cabinet belonging to the duct section in question is equipped with four legs, the positions of which coincide with the positions of the support points.
• the rack cabinet legs are intended to be placed in the support points 4bl, while the support points 4cl are used to fix the duct section 4 to the floor.
• the duct section 4 is reinforced at the aforementioned end areas 4d, 4e. This means that the cross- sectional area of the duct section in the end areas 4d, 4e is smaller than in a central area 4f situated between the end areas 4c, 4d.
• the transitions are executed in a smooth fashion, in order as far as possible to avoid the occurrence of turbulence at the transitions between the areas 4d and 4f, and 4f and 4e.
• the pressure inside the duct is also so dimensioned that the dynamic differential pressure between the end areas and the central areas of the duct sections is about 15 Pascal.
• the duct section in accordance with the present invention is, as already mentioned, that its front surface 4a lies in the same plane as the front surface 2a of the rack cabinet. Apart from the fact that this ensures that the jets of cool air from the gills 4al move along the front surface 2a of the rack cabinet, the advantage of a larger available floor area than in previously disclosed cooling ducts is also achieved. This is of significance to accessibility when servicing the telecommunications equipment in the rack cabinet.
• the gills 4al are preferably arranged on a flap 4a2 capable of being detached from the front wall 4a of the duct section 4, which flap is executed with locking devices 4a4 which engage in the wall 4a of the duct section.
• the fact that the flap 4a2 and the locking devices 4a4 are executed in a totally symmetrical fashion means that it is possible to turn the flap so that the gills point upwards, should the situation arise in which the duct section has been installed by mistake with the gills pointing downwards.
• a screen 4a3 for the gills 4al positioned furthest up is arranged on the rear side of the flap 4a2 at a certain distance from the plane of the flap and approximately parallel with it.
• the duct sections in accordance with the invention are assembled by means of set bolts of a previously disclosed kind, which interact with eye bolts 7 arranged as shown in Fig. 2.

Landscapes

• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Cooling Or The Like Of Electrical Apparatus (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20381874

Family Applications (1)

Country Status (3)

Cited By (5)

Citations (4)

• 1991
  • 1991-02-13 SE SE9100419A patent/SE466779B/sv not_active IP Right Cessation
• 1992
  • 1992-01-22 WO PCT/SE1992/000039 patent/WO1992015188A1/en active Application Filing
  • 1992-01-22 AU AU12587/92A patent/AU1258792A/en not_active Abandoned

Patent Citations (4)

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