Cooling hot power amplifiers, base stations, and other temperature-sensitive telecommunications equipment with a liquid is many times more efficient than cooling with air. But the potential for spills, which can damage expensive equipment and disrupt service, is one of several reasons why air cooling with rotary fans is currently the prevailing method.
Although flush-face, non-spill couplers exist, the trade-off for no spills is typically a restriction of cooling fluid flow within the coupling. The valves, seals, and springs that make a coupling non-spill physically block the path and decrease the flow. So the use of liquid for cooling has been more theory than reality in many telecommunications applications.
Engineers at Colder Products Co. believe their new rack-and-panel non-spill (RPN) quick coupler overcomes the flow restriction problem. "Valve design is the key," say Grant Wilhelm, the product's design engineer. "The size of the valve components is scaled so that the flow area is balanced throughout the flow path."
Cooling electronics in telecommunications equipment with liquids is a technology that is just starting to emerge, according to Wilhelm. "Electronics in these towers do a lot more and create heat as never before," he says. "The cooling problem is made worse by the fact that more heat-generating equipment goes into these cabinets. With air cooling, we are running out of AT."
"The coupling is traditionally the weakest link in the closed-loop electronic cooling system, limiting the amount of flow and, consequently, the amount of heat removal possible," says Wilhelm. "The RPN handles a flow of 14 gpm of water at 31 psi pressure drop, Cv =2.5."
Unlike other non-spill couplers, which use existing valve designs, the RPN coupler is designed from the ground up with flush-face non-spill, closed-loop liquid cooling applications in mind. "We use high-tolerance, injection molding for producing valve components that enhance flow geometry."
In telecommunications enclosure applications, the Colder coupling mates when the circuit board and associated cooling plate are installed in the data cabinet or rack. The mechanism that holds the cold plate in place keeps the coupling connected. Connecting such couplings when installing the board assembly requires no additional steps.
And importantly, when removing the circuit board for maintenance and replacement, the cooling system requires no coolant draining, thereby decreasing any possibility of spilling cooling media. Because the latching mechanism is external to the coupler, the technician installing and removing the boards is freed from special tools and additional steps.
|Contact Grant Wilhelm, Colder Products Co., 1001 Westgate Dr., St. Paul, MN; Tel: (866) 785-7972; Fax: (651) 645-5404; E-mail: [email protected] ; or Enter 502.|