Transient and troubleshoots management of aged small-scale steam power plants using Aspen Plus Dynamics

This study is motivated by the insufficient studies on the dynamic simulation, operation control optimization, and operation strategies for small-scale old plants. In such small power plants, there is a need for cautions and stability during various troubleshoots. This study aims at developing a simulation model that accurately predicts the behavior of small-scale real plants under various part loads and troubleshoots. The actual operation of a 110-MW steam power-plant was modeled using Aspen Plus Dynamics, which employs a single-input single-output proportional integral (PI) controller. The controller tuning constants, K and IT, were optimized, and operation strategies for handling five troubleshoots are proposed. The simulation results are in good agreement toward the measured values, with a maximum relative error of 2%. The recommended operation strategies could prevent plant trip and return to steady state in a maximum of 5 min when two different halts are mimicked. Full-load thermal efficiencies of 94%, 97.9%, 92.6% were achieved when four burners were shutdown, high-pressure feedwater heaters tripped, and all the heaters tripped, respectively. The simulation presents the possibility of stabilizing the old power plants operation with maximum possible efficiency under various conditions. An updated operation and troubleshoot manual can be provided for various circumstances. •Comprehensive study of an old thermal power-plant dynamic simulation model.•Three real dynamic transient operations were realized.•The PI controller tuning constants, K and IT, were optimized.•Operation strategies for handling five troubleshoots are recommended.•Updated operation and troubleshoot manual can be provided for various conditions.