A refrigeration apparatus comprising: - a main refrigerant circuit including a positive displacement compressor, a condenser, an expansion valve, and an evaporator, through which a refrigerant circulates successively in a closed loop circulation; - a lubrication refrigerant line in fluid connection with the main refrigerant circuit and connected to the compressor for lubrication of said compressor with the refrigerant; wherein: - the refrigeration apparatus comprises a refrigerant container connected between the condenser and the expansion valve, said refrigerant container being configured to retain a quantity of refrigerant, the lubrication refrigerant line being connected to said refrigerant container, - the refrigeration apparatus comprises heating means for heating the refrigerant contained in the refrigerant container, and means (26, 36, 38, CU) for allowing the circulation of refrigerant towards the compressor in the lubrication refrigerant line if a refrigerant pressure differential (ΔP), between a container pressure in the refrigerant container and a circuit pressure (P2, P3, P4) in other parts of the main refrigerant circuit isolated from the refrigerant container prior to a starting of the refrigeration apparatus, is above a threshold, the refrigeration apparatus being characterized in that said means for allowing the circulation of refrigerant towards the compressor in the lubrication refrigerant line comprise: - a refrigerant supply valve provided on the lubrication refrigerant line downstream the refrigerant container and upstream the compressor; - a first pressure sensor measuring the container pressure in the refrigerant container; - at least one second pressure sensor (38, 40, 42) measuring the circuit pressure (P2, P3, P4); - a control unit configured to compute the pressure differential (ΔP) between the container pressure and the circuit pressure (P2, P3, P4), compare the pressure differential (ΔP) to the threshold and open the refrigerant supply valve during a starting operation of the refrigeration apparatus if the pressure differential (ΔP) is above the threshold. - a main refrigerant circuit including a positive displacement compressor, a condenser, an expansion valve, and an evaporator, through which a refrigerant circulates successively in a closed loop circulation; - a lubrication refrigerant line in fluid connection with the main refrigerant circuit and connected to the compressor for lubrication of said compressor with the refrigerant; - the refrigeration apparatus comprises a refrigerant container connected between the condenser and the expansion valve, said refrigerant container being configured to retain a quantity of refrigerant, the lubrication refrigerant line being connected to said refrigerant container, - the refrigeration apparatus comprises heating means for heating the refrigerant contained in the refrigerant container, and means (26, 36, 38, CU) for allowing the circulation of refrigerant towards the compressor in the lubrication refrigerant line if a refrigerant pressure differential (ΔP), between a container pressure in the refrigerant container and a circuit pressure (P2, P3, P4) in other parts of the main refrigerant circuit isolated from the refrigerant container prior to a starting of the refrigeration apparatus, is above a threshold, the refrigeration apparatus being characterized in that said means for allowing the circulation of refrigerant towards the compressor in the lubrication refrigerant line comprise: - a refrigerant supply valve provided on the lubrication refrigerant line downstream the refrigerant container and upstream the compressor; - a first pressure sensor measuring the container pressure in the refrigerant container; - at least one second pressure sensor (38, 40, 42) measuring the circuit pressure (P2, P3, P4); - a control unit configured to compute the pressure differential (ΔP) between the container pressure and the circuit pressure (P2, P3, P4), compare the pressure differential (ΔP) to the threshold and open the refrigerant supply valve during a starting operation of the refrigeration apparatus if the pressure differential (ΔP) is above the threshold.