Dynamic model for subcritical circulating fluidized bed boiler-turbine units operated in a wide-load range. (August 2022)

• Record Type: Journal Article
• Authors: Zhang, Hongfu; Gao, Mingming; Yue, Guangxi; Zhang, Jiahui
• Is Part Of: Applied thermal engineering. Volume 213(2022)
• Publication Date: 2022-08
• Subjects: Dynamic model -- Circulating fluidized bed -- Ultra-low load -- Boiler-turbine system -- Operational flexibility; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2022.118742
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Operation characteristics of subcritical CFB unit in wide-load range are analyzed. Model can describe dynamic process of subcritical CFB unit in wide-load range. Dynamic characteristics of subcritical CFB unit in ultra-low load is presented. The model is validated by a 330 MW subcritical CFB unit. Abstract: As the proportion of renewable energy generation increases in power grid, most of circulating fluidized bed (CFB) boiler-turbine units are required to operate in a wide-load range to maintain the stability of power grid. However, few studies focus on modeling of CFB units operated in a wide-load range, especially in ultra-low load. This study develops a dynamic model for subcritical CFB boiler-turbine units operated in a wide-load range, which can provide foundation for designing flexible operation mode. In this work, different characteristics of subcritical CFB units in ultra-low load were analyzed. Then, the model structure with balance between complexity and accuracy was derives from mass and energy conservation laws as well as thermodynamic principles. The parameters and functions in model were identified based on running data from a 330 MW subcritical CFB unit. Validation results show that the of model has satisfactory accuracy in wide-load range, from ultra-low load to full load. Besides, the model can reflect essential dynamic characteristics of the unit. Therefore, the model can be feasible for performance analysis and testing control strategy.