SCD News: September 19, 2005
Keeping NCAR Computer Room cool is critical to support of atmospheric research
|
A McQuay chiller, which provides 450 tons of cooling capacity to the NCAR Computer Room. More photos |
Visitors to the NCAR Mesa Lab's Computer Room peer through a solid glass wall to see a vast area (about 8,400 square feet) filled with high-performance computers, network racks, data storage devices, and air handlers.
A unseen and complex system of pumps and pipes provides cooling for NCAR's Computer Room. More photos |
What they don't see are the hidden rooms and secret tunnels that house the infrastructure to keep all this equipment cool.
At the very back of the Computer Room is a white door. Behind that door is the SCD Mechanical Room, filled with an unimaginable array of electrical cabinets, water pumps, pipes, dials, gauges, and two large chiller machines produced by McQuay, Inc. Each chiller is the size of a car.
“One chiller is primary, one is backup. They're never online at the same time,” says Gary. “It's a lead-lag configuration. The lead changes. One will lead, the other lag; then they'll switch, so that both age identically. It's the same with the pumps. We've got two primary pumps, two secondary pumps, and two cooling tower pumps.”
The active McQuay chiller emits a loud mechanical hum, as do the pumps. This is a noisy area. It is the source of the refrigerated water that cools the air-handling units in the NCAR Computer Room, which themselves cool the air that keeps NCAR supercomputers from burning up.
The entire cooling infrastructure is sophisticated and efficient—a complex system of chillers, pumps, and pipes.
Inside the Computer Room, the supercomputers generate tremendous heat, which rises to the ceiling. Fifteen Liebert air-handler units suck in this hot air, draw it over water-cooled chiller coils (which look like fins in a car radiator) inside the units, and blow the cooled air into the space below the raised floor of the Computer Room. This cooled air passes up through floor vents in front of the supercomputers, which pull in the chilled air and pass it over their CPUs. The air heats up, is released, and once again rises to the ceiling.
The Liebert air handlers, in turn, are supplied by refrigerated water coming from the active McQuay chiller in the SCD Mechanical Room. When this refrigerated water passes through the Leiberts, it becomes warm and returns in a closed loop to the chiller. There the water is re-cooled and pumped back out to the air handlers, in a never-ending cycle.
Meanwhile, the McQuay chiller takes heat from this first closed loop of circulating water and transfers it to a second closed loop of circulating water. Water in the second loop is pumped to the cooling tower outside the Mesa Laboratory. In the tower, this water breaks into a spray of droplets and is cooled by large fans. The heat dissipates into the outside air, where it is the source of the steam often seen behind the Mesa Lab in the winter. The water droplets are collected and returned to the closed loop of circulating water, which returns to the McQuay.
All these pipes, pumps, and mechanical devices reside in a variety of back rooms and subterranean passages rarely seen by anyone but the technical staff of SCD and NCAR Physical Plant Services. But though unseen, this infrastructure is critical to the pursuit of science by NCAR's research community.
—Lynda Lester
NCAR is operated by the University Corporation for Atmospheric Research (UCAR) under the primary sponsorship of the National Science Foundation.
|
NCAR is managed
by UCAR and sponsored by the National Science Foundation |
