Refrigerant charging method in refrigeration system using carbon dioxide as refrigerant

摘要

A refrigerant charging method in an air conditioner using carbon dioxide as a refrigerant includes a first refrigerant charging step and a second refrigerant charging step. The first refrigerant charging step is a step of charging a refrigerant charging target portion including refrigerant communication pipes with refrigerant in a gas state until the pressure of the refrigerant charging target portion rises to a predetermined pressure after the start of charging. The second refrigerant charging step is a step of charging the refrigerant charging target portion with refrigerant in a liquid state until the amount of refrigerant charging the refrigerant charging target portion becomes a predetermined amount. The second refrigerant charging step occurring after the first refrigerant charging step.