Method for controlling a cooling system for autonomous cooling of a rack

A cooling system for autonomous cooling of a rack, the rack comprising at least one heat generating component, the cooling system comprising:

• at least one fan mounted onto the rack and configured for generating an air flow of ambient air within the rack, the air flow receiving at least a portion of a thermal energy generated by the at least one heat generating component in the rack;
• a closed loop comprising:
• at least one liquid cooling unit thermally coupled to the at least one heat generating component, the at least one liquid cooling unit comprising a liquid channel configured for transferring thermal energy from the at least one heat generating component to a first heat transfer fluid flowing in the liquid channel,
• a first primary side of a first liquid-to-liquid heat exchanger, the first primary side being fluidly connected to the liquid channel of the at least one liquid cooling unit, and
• at least one pump fluidly connected between the first primary side of the first liquid-to-liquid heat exchanger and the at least one liquid cooling unit, the at least one pump being configured causing the first heat transfer fluid to flow within the closed loop;
• an open loop comprising:
• an air-to-liquid heat exchanger mounted to the rack so that heated air expelled from the rack by the at least one fan flows through the air-to-liquid heat exchanger before being rejected as ambient air, the air-to-liquid heat exchanger being configured to receive a second heat transfer fluid from a first cold supply line, and
• a first secondary side of the first liquid-to-liquid heat exchanger, the first secondary side being thermally coupled to the first primary side for transfer of thermal energy from the first primary side to the first secondary side when a temperature of the first primary side is higher than a temperature of the first secondary side, the first secondary side being fluidly connected to the air-to-liquid heat exchanger, the first secondary side being configured for returning the second heat transfer fluid to a hot return line;
• and
• a controller operatively connected to the at least one fan and the at least one pump, the controller being communicatively connected to a first temperature sensor configured to measure a temperature of the second heat transfer fluid received from the first cold supply line and a second temperature sensor configured to measure a temperature of the second heat transfer fluid returning to the hot return line.

A system for controlling a cooling system of a rack, the rack comprising at least one heat generating component, the system comprising at least one processor and memory comprising executable instructions which, when executed by the at least one processor, cause the system to:

• determine a temperature difference between a temperature of heat transfer fluid received by the cooling system from a cold supply line and a temperature of heat transfer fluid returning from the cooling system to a hot return line;
• increase a rotational speed of at least one fan of the cooling system in response to the temperature difference being above a threshold;
• receive at least one first temperature indication indicative of temperature variations of heat transfer fluid circulating in at least one respective liquid channel of the cooling system;
• receive at least one second temperature indication indicative of a temperature of an air flow of ambient air within the rack, the air flow being generated by the at least one fan;
• adjust based on the at least one first temperature indication and the at least one second temperature indication, the rotational speed of the at least one fan and a rotational speed of at least one pump configured for causing the heat transfer fluid to flow in the at least one respective liquid channel;
• receive an expelled air temperature indication indicative of a temperature of ambient air being expelled from the rack;
• receive an incoming fluid temperature indication indicative of a temperature of the heat transfer fluid entering the at least one respective liquid channel;
• and
• decrease, based on the expelled air temperature indication and the incoming fluid temperature indication, the rotational speed of the at least one fan.