Supercomputer Cools Off Using Groundwater

gManZboy writes "The Department of Energy is no stranger to supercomputers, and its Pacific Northwest National Lab has proven that it can continue to be an innovator in the field by using what the lab calls a unique groundwater-fed cooling system in the lab's newest supercomputer, Olympus. The novel cooling system translates normal groundwater into big savings for the new 162 teraflop supercomputer, which is being used in energy, chemical, and fluid dynamics research. The setup translates into 70% less energy use than traditionally cooled systems."

Geothermal heat pumps

[Solandri]

When I investigated a bunch of energy-saving options for a building I was managing, geothermal heat pumps [wikipedia.org] were by far the most cost effective (not to be confused with geothermal energy). For our building, its payback time would have been 3-5 years. There are no fancy materials, no high-tech equipment involved. Just a bunch of buried/sunken plastic tubes with water flowing through them. The ancient Romans used a variant of it [i4at.org] to air condition their homes.

Essentially they're the same thing as a window heat exchanger/air conditioner, except instead of using the ambient air as the heat dump, they use the ground or groundwater/pond. This provides a much steeper and more favorable temperature gradient in both winter and summer, allowing the heat exchanger to operate much more efficiently. Whereas air is about 90 F in summer, the ground is about 55 F making it much easier to pump heat into the ground. In winter the air is about 30 F, while the ground is still about 55 F, making it much easier to pump heat out of the ground. (Below about 40-50 F, most heat exchangers just shut off and run a heating coil, because it's so inefficient trying to extract heat from air that cold.)

They're an easy energy-saving measure which quickly pays for itself. I'm surprised more new building construction doesn't incorporate it. Makes sense for cooling computers, motors, etc. too if you've already got the infrastructure in place for your home or building.

Re:how does it really work?

[will_die]

From what I have read the water doing the cooling is closed but the pipes go down into the ground and the heat transfer goes into the running groundwater.
So if you are downstream and using that water you will not notice a difference, but I cannot find anything about where the water finally goes to.

Re:how does it really work?

[JoeMerchant]

It says it's a closed loop of groundwater?

That makes no sense at all. A closed loop won't get rid of heat, just transport it. There must be a system which exchanges the heat out of the water to the environment. Maybe a radiator system, maybe a chiller, maybe an evaporative cooling system.

Or maybe it's not really a closed loop?

Step 1, pump up some groundwater.

Step 2, notice that it's pretty cool.

Step 3, feed cool water to your supercomputer to keep it cool.

Step 4, notice that you have an awful lot of excess water to deal with.

Step 5, drill another well some distance away and pump the warmer water back into the ground.

Et Voila': Closed loop.

The heat energy is being pumped into the groundwater. Groundwater is a fairly massive thermal sink. If every house in suburban Tampa tried to do this, the groundwater would heat up, but if you're a single user of a huge natural resource it appears as if you're not making any impact and "getting your energy for free."