Analysis of operating characteristics for compressed air system in heavy-duty gas turbines

The compressed air system is a critical auxiliary power source for heavy-duty gas turbines, responsible for supplying sealing pressure, driving, and cooling air to key turbine components. Its stability and reliability are crucial to the turbine's safety and operational efficiency. In the optimal operation of gas turbines, the stability of the compressed air system plays a vital role, especially in applications with multiple air-source users, where fluctuations in fluid pressure can significantly impact system stability. To assess the supply capability of the 300 MW F-class heavy-duty gas turbine’s compressed air system, this paper utilizes transient dynamic analysis and develops a transient computational fluid dynamics (CFD) model for the system's pipeline. The model simulates the system's performance under various operating conditions and evaluates the pipeline’s supply capabilities. This study explores the influence of factors such as the number of users, gas consumption intervals, and usage modes on system pressure fluctuations. The results show that increasing the number of users and extending the cycle time can significantly reduce pressure fluctuations in the system. Specifically, conditions with multiple users and longer cycles lead to improved stability. Furthermore, selecting an appropriate flow switching mode, such as periodic oscillation, further diminishes the amplitude of pressure fluctuations and enhances overall system stability. By optimizing the gas consumption intervals, flow fluctuations can be more effectively balanced, contributing to more stable system operation. This research offers theoretical guidance and practical insights for the optimization of compressed air pipeline systems and the safe management of gas consumption behaviors at the user end.