GB974555A - Refrigerating machine - Google Patents

Abstract

974,555. Refrigerating. TRANE CO. June 27, 1963 [Aug. 15, 1962], No. 25708/63. Heading F4H. [Also in Division H2] In a refrigeration system com prising a motor-driven compressol the motor is cooled by liquid refrigerant supplied thereto from the condenser via an economizer and liquid refrigerant is only supplied from the economizer to the evaporator when the level of refrigerant in the motor casing reaches a predetermined value. As shown in Fig. 1, the system comprises first and second stage compressors 12, 14 driven by a motor 10, a condenser 22, an economizer 27 mounted on the motor casing and an evaporator 70. Liquid refrigerant from the condenser passes to the economizer through a line 26 and thence to the motor casing to cool the stator 38. Refrigerant vapour from the economizer and the motor casing passes through a line 62 to a line 16 linking the compressor stages while liquid refrigerant passes from the economizer to the evaporator 70 when the refrigerant level reaches that of an outlet line 64. Annular passages are formed in the stator to permit liquid refrigerant circulation and the rotor 56 is disposed in a separate sealed compartment filled with refrigerant vapour which is circulated by fan blades 58 formed on the rotor to cool the latter and the end windings 59 of the stator. In the embodiment of Fig. 4, the economizer 82 communicates with the bottom of the motor easing through a line 88 which communicates at its upper end with a conduit 92 leading to the evaporator so that liquid refrigerant only passes to the evaporator when the liquid level in line 88, and hence in the motor casing, reaches the inlet to conduit 92.