Physical Modelling of BlueScope Steel’s Steelworks Cogeneration Plant Saltwater Cooling System, Port Kembla

Client: BlueScope Steel Pty Ltd
Year: 2008-2009
Project Reference: 08035
WRL Technical Report: Physical Modelling of BlueScope Steel’s Steelworks Cogeneration Plant Saltwater Cooling System, Port Kembla (2009/01)

(Clockwise from top) Flow pattern in the tundish for 100% design flow/high tide/no fouling; Flow pattern in the outlet for 100% design flow/high tide/no fouling; Flow pattern in the outlet pipe for 100% design flow/high tide/no fouling; Flow pattern in the air release structure for 100% design flow/high tide/no fouling.

The Water Research Laboratory (WRL) has undertaken physical modelling of a proposed section of the saltwater cooling system at the Port Kembla Steelworks Cogeneration Plant. BlueScope Steel’s Steelworks Cogeneration Plant will use saltwater for turbine condenser cooling. The flow will come from condensers and enter a tundish, where it will flow over a weir and through dual outlet concrete pipes. Further downstream, about 800 m from the tundish, the pipes combine into a discharge structure where the flow enters the harbour with tides affecting the outlet conditions. It has been identified that at some flows, tidal levels, and fouling conditions, air entrainment is a distinct possibility which has potential for serious negative impacts on system operation.

The model investigated flow through inlet pipes into the tundish and out through discharge pipes for varying flows, ocean tide levels and fouling conditions. The first phase of testing concentrated on flow patterns, air entrainment motion and the quantity of air released within the tundish, discharge pipes and air release structures. This testing allowed for evaluation of the initial design and showed opportunities for improved flow conditions in modifying the model design: changing the height and shape of the weir within the tundish, and installing bellmouths in the outlet pipes. Modifications of the model design were undertaken for a second phase of testing and showed generally improved conditions in terms of air entrainment and flow patterns. They generated reduced turbulence and aeration within the tundish and less air suction into the outlet pipes as well as better performance of the air release structures.