Typically, refrigeration systems are modeled with a combination of Refrigeration:Case and Refrigeration:CompressorRack objects. This is how walk-in freezer/cooler and refrigerated display case systems are modeled in the Hospital, RestaurantFastFood, RestaurantSitDown, SchoolPrimary, and SchoolSecondary Commercial Prototype Building Models. There are other ways of modeling refrigeration systems, including Refrigeration:AirChiller and ZoneHVAC:RefrigerationChillerSet (see ExampleFiles), but I don't believe any of these objects support absorption chillers.

Depending on the zone load and the setpoint temperature that your cold storage room needs to maintain, it may be possible to serve the room with an air system that utilizes chilled water from an absorption chiller (similar to a CRAH), but this would probably be classified as a special air handling system rather than a refrigeration system.