Abstract: A device for separating a gaseous and a liquid phase of a working medium and for storing the liquid phase. The device has a volume enclosing wall with closed end faces, an inlet and an outlet, as well as a suction pipe. A partition element is arranged within the volume, which divides the volume in a separation volume and a storage volume. The separation volume is formed above the partition element in a direction z of gravity, while the storage volume is formed below the partition element. The suction pipe opens into the separation volume.