Apparatus and method for adjusting coolant flow resistance through liquid-cooled electronics rack(s)

A method of cooling a plurality of electronics racks, each electronics rack comprising a heat exchange assembly, the method comprising:

• obtaining a cooling apparatus comprising:
• a plurality of coolant supply lines and a plurality of coolant return lines coupled in fluid communication between a coolant distribution unit and the heat exchange assemblies of the plurality of electronics racks, the coolant distribution unit supplying cooled system coolant for the heat exchange assemblies, wherein when operational, system coolant circulates in a closed loop between the coolant distribution unit and the heat exchange assemblies via, at least in part, the plurality of coolant supply lines and the plurality of coolant return lines;
• and
• a plurality of rack flow restrictors associated with at least one of the plurality of coolant supply lines, the plurality of coolant return lines, or the heat exchange assemblies of the plurality of electronics racks, each rack flow restrictor being associated with a respective coolant supply line of the plurality of coolant supply lines, a respective coolant return line of the plurality of coolant return lines, or a respective heat exchange assembly of the heat exchange assembles, for tailoring coolant flow resistance through the heat exchange assembly of the respective electronics rack, and wherein the plurality of rack flow restrictors tailor coolant flow resistance through at least one of the plurality of coolant supply lines, the plurality of coolant return lines, or the heat exchange assemblies to enhance overall heat transfer through the heat exchange assemblies of the plurality of electronics racks;
• and
• cooling the plurality of electronics racks, the cooling comprising:
• collecting rack power utilization data for each electronics rack of the plurality of electronics racks;
• summing the rack power utilizations of the plurality of electronics racks and determining a total coolant flow required to cool the plurality of electronics racks, and based on the total coolant flow required, automatically setting a rate of cooled system coolant supplied by the coolant distribution unit;
• determining the highest power utilizing electronics rack of the plurality of electronics racks and automatically setting the rack flow restrictor associated therewith to full open position;
• ascertaining coolant pressure and temperature information at the heat exchange assemblies of the plurality of electronics racks;
• and
• setting rack flow restrictors associated with the remaining electronics racks of the plurality of electronics racks to ensure coolant exhausting from the heat exchange assemblies of the remaining electronics racks is in a super heated vapor state within a specified range of superheated temperatures based on the collected coolant pressure and temperature information.