To provide an absorption system including a plurality of triple utility type absorption refrigerating machines connected by cross-cover communication wiring and a central controlling unit, which decreases the corrosion rate of absorbent and improves the fuel efficiency.

Data of partial load characteristic is saved in a central controlling unit and data of the rated capabilities of absorption refrigerating machines that are connected to each other are central-controlled. Accordingly, it becomes possible to made each of the absorption refrigerating machines perform the partial load operation mainly. Consequently, the operation is able to keep low the regeneration temperature of lean solution, reduce the corrosion rate and improve the fuel efficiency. In terms of improving the fuel efficiency, it is not particularly limited to a triple utility type absorption refrigerating machine but is effective to a dual utility type absorption refrigerating machine, as operation control means for an absorption system.