Research on Boiler Drum Dynamic Model with Bond Graph

Drum level parameter in power natural circulation boiler is required to supervise and maintain for safety and efficiency and creating its accurate model to analyze system dynamic behaviors is critical for improving control performance. A power bond graph model of boiler vaporization system is firstly proposed in the paper. Due to complicated energy and mass transferring in boiler circuit vaporization system, a multi-ports C field of bond graph model is established to present control volume model with accumulating hydraulic and thermal energy. Bond graph sub-models with multi-ports C element are built and connected to obtain an integral model of boiler vaporization. The math descriptions for bond graph model of subsystem are also given. The simulation curves show that this bond graph model can effectively describe process characteristic and testify the "shrink and swell" phenomenon in boiler drum under the variable operation condition. This provides a new approach for modeling thermal process