Hydraulic Analysis have carried out dynamic simulation studies on many Steam Systems. Our two largest steam projects to date are the Sadara Refinery in Saudi Arabia and the RAPID (Refinery and Petrochemical Integrated Development) project for Petronas.
We carry out a detailed performance analysis on steam systems to determine the peak/minimum pressures, temperature changes and pipe forces which will be generated following various upset events. We also help to optimise the process control system to ensure the plant is safe to operate under multiple different disturbance scenarios. We can model multiple producers and consumers of steam at various different pressure levels connected by let-down stations. This allowed the effects of a disturbance in one zone to be fully evaluated as the pressure waves pass through the let-down stations. We can also account for wind speed across the pipework which results in forced convection instead of free convection and has an impact on the temperature losses.
We can model boilers and turbines and have developed a methodology to generate a turbine performance curve from turbine data sheets to separate the effects of the valves from that of the turbine. Turbine data sheets and steam consumption charts (Willans Lines) are normally applied across the complete turbine package including inlet stop valve(s), inlet governor valve(s), exhaust non-return valves and all associated inter-connecting pipework, and not directly across the actual steam turbine itself. By presenting the data in this format, the manufacturers assume that any pressure, flow or temperature changes in the system will be gradual and hence the governor valve will have time to recover and ensure stable turbine performance. This carried a huge assumption that the governor valve will always be able to react to transients and they will not be passed into the turbine which is often not the case following an upset event. We can model the inertial effects of turbines to accurately show the change in their performance following a change in operating conditions.