Cooling system

A cooling system, configured for cooling a machine tool, the machine tool having a machine temperature, the cooling system comprising:

• a gas source, configured for providing a gas;
• a refrigeration circulation, comprising a heat exchanger, a compressor, a condenser, and an expansion valve, wherein the heat exchanger is in fluid communication with the gas source and is configured to cool the gas down to a target temperature and to provide the gas to the machine tool, and the compressor has an operation frequency;
• a fan, configured to cool the condenser, wherein the fan has a rotation speed;
• a controller, connected to the compressor and the fan;
• and
• a supplying module, connected to the heat exchanger, wherein the supplying module is configured to supply the gas and a lubricating fluid to the machine tool;
• wherein when a target temperature difference that is equal to the machine temperature minus the target temperature is smaller than a threshold temperature difference, the controller keeps the operation frequency at a minimum frequency and sets the rotation speed to be smaller than a maximum rotation speed, the controller is connected to the supplying module, the controller is configured control the supplying module to supply the gas and a lubricating fluid to the machine tool at a specific time interval.