Air-cooled ammonia refrigeration systems and methods

A method of providing refrigeration using an air-cooled ammonia refrigeration system, the method comprising:

• supplying vaporous ammonia to an air-cooled condenser comprising a heat exchanger and at least one axial fan;
• condensing, with the air-cooled condenser, the vaporous ammonia to form liquid ammonia;
• removing, with a subcooler, heat from the liquid ammonia;
• evaporating, with an evaporator, the liquid ammonia from the subcooler to form vaporous ammonia;
• and pulsing, with a control circuit, atomized water through a plurality of spray nozzles positioned below the air-cooled condenser to a surface of the air-cooled condenser when a head pressure of the air-cooled condenser is higher than a predetermined value;
• and wherein the atomized water is pulsed by the control circuit such that the atomized water evaporates upon contact with the surface of the air-cooled condenser.

An air-cooled ammonia refrigeration system, the system comprising:

• an air-cooled condenser comprising a finned tube heat exchanger having a tube diameter of at least about 0.5 inches and a fin density of at least about 12 fins per inch, and at least one axial fan, the air-cooled condenser configured to condense vaporous ammonia to form liquid ammonia;
• an evaporator coupled to the air-cooled condenser and configured to evaporate liquid ammonia received from the air-cooled condenser to form vaporous ammonia;
• a subcooler positioned between the air-cooled condenser and the evaporator and configured to remove heat from the liquid ammonia passing from the air-cooled condenser to the evaporator;
• a compressor coupled to the evaporator and configured to compress the vaporous ammonia received from the evaporator;
• an oil cooler coupled to the compressor and configured to remove heat from circulating oil in the compressor;
• a water system coupled to the air-cooled condenser, the water system comprising a water source, a water pump, and a plurality of spray nozzles positioned below the air-cooled condenser;
• a control circuit coupled to the air-cooled condenser and the water system, the control circuit configured to pulse atomized water through the plurality of spray nozzles to a surface of the air-cooled condenser when a head pressure of the air-cooled condenser is higher than a predetermined value such that the atomized water evaporates upon contact with the surface of the air-cooled condenser;
• and
• a plurality of legs configured to elevate the heat exchanger at least about 10 feet above a roof surface or at least about 20 feet above a ground surface.