Abstract: A refrigerating system according to the invention includes a refrigerant circuit having at least one compressor, a condenser/gascooler, an intermediate pressure container, at least one evaporator and a respective expansion device before said at least one evaporator, and refrigerant pipes connecting said elements and circulating a refrigerant therethrough; a high pressure regulating device between the condenser/gascooler and the intermediate pressure container, expanding the refrigerant from a high pressure level to an intermediate pressure level; an intermediate pressure sensor sensing the intermediate pressure level; and a control unit controlling the high pressure regulating device. The control unit in operation limits the maximum refrigerant flow through the high pressure regulating device to a maximum flow value FMax, if the sensed intermediate pressure level exceeds a predetermined threshold value PIntTh.

Abstract: A refrigerating system according to the invention comprises a refrigerant circuit (2) having at least one compressor (4), a condenser/gascooler (6), an intermediate pressure container (8), at least one evaporator (10) and a respective expansion device (12) before said at least one evaporator (10), and refrigerant pipes (14) connecting said elements and circulating a refrigerant therethrough; a high pressure regulating device (16) between the condenser/gas-cooler (6) and the intermediate pressure container (8), expanding the refrigerant from a high pressure level to an intermediate pressure level; an intermediate pressure sensor sensing the intermediate pressure level; and a control unit (18) controlling the high pressure regulating device (16). The control unit (18) in operation limits the maximum refrigerant flow through the high pressure regulating device (16) to a maximum flow value FMax, if the sensed intermediate pressure level exceeds a predetermined threshold value PIntTh.

Abstract: Refrigerant circuit (2) comprising a low pressure compressor unit (38) having a low pressure refrigerant outlet (42) in a low pressure sub-circuit (4) and a higher pressure compressor unit (8) having a higher pressure refrigerant inlet (12) in a higher pressure sub-circuit (6), wherein the low pressure refrigerant outlet (42) and the higher pressure refrigerant inlet (12) are fluidly connected with each other, further comprising an oil reservoir (56) connected by a low pressure oil inlet conduit (54) to the low pressure sub-circuit (4) for receiving oil therefrom and connected via an oil discharge (62) to the higher pressure sub-circuit (6).