Method and system for filling a refrigerant into a refrigeration system

1. A method of filling a refrigerant into a refrigeration system using a filling system including a tank, the method comprising:

pressurizing the tank using a conditioning process to a predetermined differential pressure above a saturation pressure of an actual ambient temperature before the refrigerant is transferred from the tank to the refrigeration system, the tank conditioning process including circulating the refrigerant from the tank through a heated suction accumulator by:

opening a tank outlet valve in an outlet line that runs from the tank to the refrigeration system;

opening a refrigerant return valve in a refrigerant return line connecting the outlet line with an inlet line upstream of the heated suction accumulator; and

closing a system outlet valve in the outlet line downstream of the connection point of the refrigerant return line.

2. The method of claim 1 , wherein the conditioning process continues until a predetermined temperature difference between a temperature of the refrigerant in the tank and the ambient temperature has been reached.

3. The method of claim 2 , wherein the predetermined temperature difference is determined based on a design of the filling system.

4. The method of claim 2 , wherein the conditioning process continues until the temperature of the refrigerant in the tank is at least 11° C. higher than the ambient temperature.

5. The method of claim 1 , wherein the pressurizing is done by means of a compressor, and the method further comprising:

conveying refrigerant, which has been compressed by the compressor, to the tank, extracting refrigerant from the tank; and

returning expanded refrigerant to an inlet side of the compressor;

wherein circulation of refrigerant is maintained until the predetermined differential pressure above the saturation pressure of the actual ambient temperature is achieved.

6. The method of claim 5 , wherein the refrigerant is vaporized before it is supplied to the compressor.

7. The method of claim 6 , wherein the conditioning process continues until a majority of the refrigerant in the tank is vaporized.

8. A filling system for filling a refrigerant in a tank into a refrigeration system, the filling system comprising:

a compressor configured to compress the refrigerant, a fluid connection fluidly connecting the compressor to the refrigeration system;

a refrigerant return line connecting an outlet line and an inlet line and configured to return the refrigerant from the tank to a low pressure side of the compressor, the refrigerant return line having a switchable refrigerant return valve and a one-way valve located downstream of the refrigerant return valve; and

at least two temperature sensors which are respectively configured for measuring a temperature of the refrigerant in the tank and an ambient temperature;

wherein the filling system is configured to operate the compressor to increase the temperature in the tank until a predetermined differential temperature above an actual ambient temperature has been reached.

9. The filling system of claim 8 , further comprising a venting valve and an orifice fluidly connected to the tank and a pressure sensor configured to measure pressure of the refrigerant in the tank, the venting valve and the orifice being configured to vent excess gas from the tank to the environment.

10. A filling system for filling a refrigerant in a tank into a refrigeration system, the system comprising:

a compressor configured to compress the refrigerant, a fluid connection fluidly connecting the compressor to the refrigeration system;

a refrigerant return line connecting an outlet line and an inlet line and configured to return the refrigerant from the tank to a low pressure side of the compressor, the refrigerant return line having a switchable refrigerant return valve and a one-way valve located downstream of the refrigerant return valve;

a temperature sensor configured to measure ambient temperature; and

a pressure sensor configured to measure pressure of the refrigerant in the tank;

wherein the filling system is configured to operate the compressor to increase the pressure in the tank until a predetermined differential pressure above a saturation pressure of the actual ambient temperature has been reached.

11. The filling system of claim 8 , further comprising:

a heated suction accumulator configured to evaporate the refrigerant before it is supplied to the compressor.

12. The filling system of claim 10 , further comprising:

a heated suction accumulator configured to evaporate the refrigerant before it is supplied to the compressor.

13. The filling system of claim 10 , further comprising a venting valve and an orifice fluidly connected to the tank and the pressure sensor, the venting valve and the orifice being configured to vent excess gas from the tank to the environment.