5 or 8 kW refrigerating system and centrifugal compressor assembly for said system

PCT No. PCT/RU96/00095 Sec. 371 Date Sep. 11, 1998 Sec. 102(e) Date Sep. 11, 1998 PCT Filed Apr. 26, 1996 PCT Pub. No. WO97/39292 PCT Pub. Date Oct. 23, 1997A refrigerating system has a condenser, an evaporator, and a two-stage centrifugal compressor assembly with an electric motor provided with a cooling system. A condenser inlet is connected to a compressor assembly outlet, while a condenser outlet is connected via first and second choke elements to an inlet of the evaporator and to the cooling system. The evaporator outlet communicates with the compressor assembly inlet, and the cooling system outlet communicates with the inlet of the second stage of the assembly. The cooling system is provide with a cooling skirt having a cavity of the cooling system lying between a stator and a housing. The refrigerating system has a separator vessel, a recuperative heat exchanger, and a heat-regulating valve controlled by the coolant pressure and temperature at the cooling skirt inlet, and also fitted in series with the separator vessel in the line connecting the condenser inlet to the evaporator. The separator vessel is connected by a gas phase to the coolant feed duct. The heat exchanger is connected by the coolant to a line connecting the condenser outlet to the evaporator inlet via the separator vessel. The second choke element is a heat-controlled valve regulated by the pressure and temperature of the coolant in the coolant discharge line from the cooling skirt.