A compression refrigeration machine is provided having ammonia as a refriant and including a condenser, a throttle device, an evaporator device, and a motor-compressor unit. The motor compressor unit includes an electric motor that drives a compressor and may be arranged in a semi-hermetic or hermetic encapsulation. In an hermetic encapsulation, the electric motor is located outside a suction gas stream flowing into the compressor and outside a discharge gas stream exiting from the compressor so that the electric motor is only exposed to an essentially static ammonia atmosphere. The motor-compressor unit and the semi-hermetic encapsulation are composed of materials stable or resistant to ammonia.
- Jun 28, 2020-