Cooling system

A method comprising:

• storing, by a flash tank, a refrigerant;
• using, by a medium temperature load, the refrigerant from the flash tank to cool a space proximate the medium temperature load to a first temperature;
• using, by a low temperature load, the refrigerant from the flash tank to cool a space proximate the low temperature load to a second temperature that is lower than the first temperature;
• compressing, by a first compressor, the refrigerant from the low temperature load;
• compressing, by a second compressor, the refrigerant from the medium temperature load;
• directing, by an ejector, a mixture of the refrigerant from the first compressor and the refrigerant from the second compressor to the low temperature load during a defrost cycle, the mixture defrosts the low temperature load;
• and
• receiving, by the flash tank, the mixture.

A system comprising:

• a high side heat exchanger configured to remove heat from a refrigerant;
• a flash tank configured to store the refrigerant from the high side heat exchanger;
• a medium temperature load configured to use the refrigerant from the flash tank to cool a space proximate the medium temperature load to a first temperature;
• a low temperature load configured to use the refrigerant from the flash tank to cool a space proximate the low temperature load to a second temperature that is lower than the first temperature;
• a first compressor configured to compress the refrigerant from the low temperature load;
• a second compressor configured to compress the refrigerant from the medium temperature load;
• and
• an ejector configured to direct a mixture of the refrigerant from the first compressor and the refrigerant from the second compressor to the low temperature load during a defrost cycle, the mixture defrosts the low temperature load, the flash tank further configured to receive the mixture.