Cooling unit for container-type data center

A data center comprising:

• a plurality of electronics racks;
• a container housing the plurality of electronics racks;
• a coolant loop facilitating extraction of heat generated within one or more of the electronics racks of the plurality of electronics racks housed within the container;
• and
• a multi-mode cooling unit coupled to the coolant loop, the multi-mode cooling unit comprising:
• a heat rejection unit coupled in fluid communication with the coolant loop for rejecting heat from coolant passing through the coolant loop to air passing across the heat rejection unit, the heat rejection unit comprising:
• a heat exchange assembly, the heat exchange assembly comprising a first heat exchanger and a second heat exchanger;
• at least one air-moving device for providing airflow across the first heat exchanger and the second heat exchanger of the heat exchange assembly;
• a controller operating the multi-mode cooling unit in a first cooling mode, wherein the second heat exchanger is OFF and heat is rejected from the coolant via the airflow passing across the first heat exchanger, and a second cooling mode, wherein the second heat exchanger is ON and heat is rejected from the coolant via the airflow passing across the first heat exchanger and the second heat exchanger;
• a first coolant outlet line from the multi-mode cooling unit and a second coolant outlet line from the multi-mode cooling unit, wherein in the first cooling mode coolant output from the multi-mode cooling unit passes through the first coolant outlet line, and in the second cooling mode a first portion of coolant output from the multi-mode cooling unit passes through the first coolant outlet line and a second portion of coolant output from the multi-mode cooling unit passes through the second coolant outlet line, the first and second coolant outlet lines being coupled in fluid communication with the coolant loop;
• a controllable valve, the controller controlling the controllable valve to direct the coolant towards at least one of the first coolant output line or the second coolant output line dependent on whether the multi-mode cooling unit is in the first cooling mode or the second cooling mode;
• a refrigeration unit associated with the second coolant outlet line and comprising a coolant-to-refrigerant heat exchanger, the refrigeration unit being OFF in the first cooling mode and ON in the second cooling mode, and being controllable in the second cooling mode to selectively extract heat from the second portion of coolant passing through the second coolant outlet line via the coolant-to-refrigerant heat exchanger so that in the second cooling mode the second portion of coolant passing through the second coolant outlet line is at a cooler temperature than the first portion of coolant passing through the first coolant outlet line of the multi-mode cooling unit;
• and
• wherein the first heat exchanger of the heat exchange assembly is coupled in fluid communication with the coolant loop, and the second heat exchanger of the heat exchange assembly is coupled in fluid communication with a refrigeration loop of the refrigeration unit.

A method of fabricating a cooling unit for a data center, the method comprising:

• providing a multi-mode cooling unit coupled, via a coolant loop, to cool one or more electronics racks of the data center, the multi-mode cooling unit comprising:
• a heat rejection unit for rejecting heat from coolant passing through the coolant loop to air passing across the heat rejection unit, the heat rejection unit comprising:
• a heat exchange assembly, the heat exchange assembly comprising a first heat exchanger and a second heat exchanger;
• at least one air-moving device for providing airflow across the first heat exchanger and the second heat exchanger of the heat exchange assembly;
• a controller operating the multi-mode cooling unit in a first cooling mode, wherein the second heat exchanger is OFF and heat is rejected from the coolant via the airflow passing across the first heat exchanger, and a second cooling mode, wherein the second heat exchanger is ON and heat is rejected from the coolant via the airflow passing across the first heat exchanger and the second heat exchanger;
• a first coolant outlet line from the multi-mode cooling unit and a second coolant outlet line from the multi-mode cooling unit, wherein in the first cooling mode coolant output from the multi-mode cooling unit passes through the first coolant outlet line, and in the second cooling mode a first portion of coolant output from the multi-mode cooling unit passes through the first coolant outlet line and a second portion of coolant output from the multi-mode cooling unit passes through the second coolant outlet line, the first and second coolant outlet lines being coupled in fluid communication with the coolant loop;
• a controllable valve, the controller controlling the controllable valve to direct the coolant towards at least one of the first coolant output line or the second coolant output line dependent on whether the multi-mode cooling unit is in the first cooling mode or the second cooling mode;
• a refrigeration unit associated with the second coolant outlet line and comprising a coolant-to-refrigerant heat exchanger, the refrigeration unit being OFF in the first cooling mode and ON in the second cooling mode, and being controllable in the second cooling mode to selectively extract heat from the second portion of coolant passing through the second coolant outlet line via the coolant-to-refrigerant heat exchanger so that in the second cooling mode the second portion of coolant passing through the second coolant outlet line is at a cooler temperature than the first portion of coolant passing through the first coolant outlet line of the multi-mode cooling unit;
• and
• wherein the first heat exchanger of the heat exchange assembly is coupled in fluid communication with the coolant loop, and the second heat exchanger of the heat exchange assembly is coupled in fluid communication with a refrigeration loop of the refrigeration unit.