Direct expansion ammonia refrigeration system and a method of direct expansion ammonia refrigeration

A direct expansion ammonia refrigeration system, comprising:

• a source of liquid ammonia refrigerant;
• and
• a direct expansion ammonia evaporator having a plurality of evaporation tubes coupled in fluid receiving relation relative to the source of liquid ammonia refrigerant, and which each has an inside facing surface having a wicking structure, and wherein by capillary action, the wicking structure facilitates the drawing of the liquid ammonia refrigerant up and along the inside facing surface of the respective evaporator tubes so as to substantially reduce any stratified and/or wavy flow patterns of the liquid ammonia refrigerant within the respective evaporator tubes;
• a compressor coupled to the source of liquid ammonia refrigerant, and which supplies the liquid ammonia refrigerant to the direct expansion ammonia evaporator;
• an accumulator vessel coupled in fluid delivering relation relative to the direct expansion ammonia evaporator and in fluid delivering relation relative to the compressor;
• and
• a heated heat exchanger vessel coupled in both fluid receiving and delivering relation relative to the accumulator vessel, and which produces substantially dry ammonia vapor.