Selection of a cooling system for the integrated high-frequency electric drive of refrigeration centrifugal compressors

Refrigeration system of the integral high-frequency motor of centrifugal compressors for water-chilling machines are compared in the article. The schemes of refrigeration by refrigerant vapor removed from the cycle on the level of suction pressure into the compressor and on the level of compressor pressure after the first stage, as well as the scheme of refrigeration with the help of water jacket are considered in detail. It is shown that refrigeration through heat removal with the help of water jacket is the most efficient, with the efficiency rising with decreasing of pressure in the area of drive and of the molecular mass of the refrigerant. In general refrigeration with refrigerant vapor circulating in the system is always more advantageous from the energy point of view, than the supply of additional amount of liquid refrigerant.