System and method for phase-change cooling of an electronic rack

An electronic rack comprising:

• a plurality of pieces of information technology (IT) equipment arranged in a stack for providing data processing services, each piece of IT equipment including one or more processors;
• a primary condenser;
• a primary supply line and a primary return line that couples the primary condenser to a cold plate that is arranged to mount on a processor of a piece of IT equipment of the plurality of pieces of IT equipment to create a primary heat-transfer loop in which the primary condenser 1) supplies, via the primary supply line, liquid coolant to the cold plate and 2) receives, via the primary return line, vapor that is produced by the cold plate when heat generated by the processor is transferred into the liquid coolant by the cold plate;
• a secondary condenser;
• a secondary supply line that couples the secondary condenser to the primary supply line;
• a secondary return line that couples the secondary condenser to the primary return line;
• and
• a primary valve that is coupled to the secondary return line,
• wherein the primary valve is configured to at least partially open in response to a pressure of the vapor exceeding a pressure threshold,
• wherein, in response to the primary valve at least partially opening, a secondary heat-transfer loop is created in which the secondary condenser receives, via the secondary return line, at least a portion of the vapor and condenses the at least the portion of the vapor back into liquid coolant that is supplied, via the secondary supply line, to the primary supply line.

A method for liquid cooling an information technology (IT) component of a piece of IT equipment that is mounted within an electronic rack, the method comprising:

• determining a vapor pressure within a primary heat-transfer loop in which a cold plate mounted on the IT component is coupled to a primary condenser with 1) a primary supply line that supplies liquid coolant to the cold plate, and 2) a primary return line that returns vapor produced by the cold plate when heat generated by the IT component is transferred into the liquid coolant by the cold plate to the primary condenser;
• in response to determining that the vapor pressure within the primary heat-transfer loop exceeds a pressure threshold, opening a closed primary valve that couples the primary return line to a secondary condenser that is coupled to the primary supply line with a secondary supply line, wherein upon the opening of the closed primary valve a secondary heat-transfer loop is created in which at least a portion of the vapor is condensed by the secondary condenser back into liquid coolant that is supplied, via the secondary supply line, to the primary supply line;
• and
• in response to determining that the vapor pressure within the primary heat-transfer loop does not exceed the pressure threshold, maintaining closure of the closed primary valve such that only the primary condenser condenses the vapor back into liquid coolant.