Austrian international technology group major Andritz AG (ANDRITZ) has announced that is has completed a major modernization project at a cogeneration plant in Zagreb, Croatia.
ANDRITZ replaced an outdated high-pressure steam boiler, which had reached the end of its operational life, with a modern low-pressure steam boiler.
This upgrade significantly improves the plant’s reliability, strengthening the overall operational stability of the Zagreb heating system. It also increases fuel efficiency and reduces maintenance requirements.
The new boiler was installed inside the existing boiler house. The project scope included the removal of the old equipment and the civil works required for the integration of the new unit.
Despite space constraints and demanding installation conditions, the Zagreb project was executed in accordance with all technical and safety standards.
The boiler has a capacity of 63 tonnes of steam per hour and operates within a pressure range of 14–17 bar(g) at 235 °C, ensuring stable steam production for industrial processes and the city’s heating system.
Classified as a medium combustion plant with a fuel input below 50 MW, the unit fully complies with national emission regulations. Natural gas serves as the primary fuel, while light fuel oil (LFO) is available as a secure backup option.

