US Patent No. 10,342,165

DATA CENTER COOLANT SWITCH


Patent No. 10,342,165
Issue Date July 02, 2019
Title Data Center Coolant Switch
Inventorship Madhusudan K. Iyengar, Woodstock, NY (US)
Pritish R. Parida, Fishkill, NY (US)
Mark D. Schultz, Ossining, NY (US)
Assignee International Business Machines Corporation, Armonk, NY (US)

Claim of US Patent No. 10,342,165

1. A system for cooling a data center, comprising:an indoor portion wherein heat is absorbed from components in said data center during a first mode of operation and during a second mode of operation;
an outdoor heat exchanger portion wherein outside air is used to cool a first heat transfer fluid present in at least said outdoor heat exchanger portion during said first mode of operation, said first heat transfer fluid being water and having a first freezing point;
a coolant switch arrangement configured to switch said outdoor heat exchanger portion to a second heat transfer fluid, in preparation for operation in said second mode of operation, said second heat transfer fluid being one of ethylene glycol and an ethylene glycol-water mixture and having a second freezing point lower than said first freezing point, said second freezing point being sufficiently low for said second heat transfer fluid not to freeze when an outdoor air temperature adjacent said outdoor heat exchanger portion drops below a first predetermined relationship with said first freezing point, said second heat transfer fluid has a higher viscosity than said first heat transfer fluid, said second heat transfer fluid having a lower ability to conduct and carry heat than said first heat transfer fluid; and
a control unit coupled to said coolant switch arrangement and configured to determine that an appropriate time has been reached to switch from said first mode to said second mode,
wherein said coolant switch arrangement switches said outdoor heat exchanger portion to said second heat transfer fluid responsive to said determination by said control unit, and
wherein said heat is absorbed from said components in said data center into said second heat transfer fluid and wherein said outside air is used to cool said second heat transfer fluid present in at least said outdoor heat exchanger portion of said cooling system during said second mode;
said control unit further configured to determine that an appropriate time has been reached to switch from said second mode back to said first mode, wherein the appropriate time is when an outdoor air temperature has reached a second predetermined relationship with the first heat transfer fluid freezing point and, responsive to determining that said appropriate time has been reached to switch from said second mode back to said first mode, switch said outdoor heat exchanger portion of said cooling system back to said first heat transfer fluid.