IES Consulting was commissioned to perform internal DSM and CFD analysis to determine the conditions within the transformer bay and transformer radiator bay of the zone substation of City Power on Waratah Place in Melbourne. Steady state CFD simulations were performed to look at temperature distribution in these rooms under the worst case external weather conditions.
The consultants used the IES VE to model and carry out an annual analysis to examine the temperature variations in the zones throughout the course of a year, reporting on the minimum and maximum temperatures achieved. They then chose the worst case scenario and looked at that scenario in detail in the CFD model to derive the conditions like surface temperatures of the walls and the flow through natural ventilation openings from the results using ApacheSim and MacroFlo. They then applied those to the CFD model and looked at the actual vertical variation in the space.
The biggest challenge of this project was dealing with high heat gains brought by Australia Summertime and trying to find out what kind of temperature distribution there would be in the radiator using natural ventilation only and if that would be enough on its own to ensure safety of the radiators.
A blockage scenario was analysed where the louvres were assumed to be blocked partly to reduce opening area. The CFD simulations were able to display the thermal stratification occurring in the rooms due to the concentration of heat gains near the floor. The thermal stratification was noted to assist in ensuring that the air entering the transformer bay was cooler than had been predicted by the DSM approach which helped keep the temperature in the transformer bay in check and near the threshold value. The stratification aid resulted in the average temperature being 8oC lower than the DSM prediction for the transformer radiator bay and kept the average temperature well below the required threshold.