Analysis of Steam Turbine Sealing Technology: The Guardian of Efficient Operation

During the operation of a steam turbine, its rotor rotates at high speeds. To prevent friction arising from the dynamic-to-static clearances between the main shaft and the turbine casing ends-and to avoid steam leakage caused by pressure differentials within the casing-shaft-end seals are employed to seal these gaps. Concurrently, to further enhance efficiency and ensure unit safety, appropriate sealing measures must also be implemented within the casing to address the clearances between the rotor and the stationary components. These sealing measures can be categorized based on their installation locations, including shaft-end seals, flow-path seals, and diaphragm seals.

Functions and Classification of Steam Seals

During steam turbine operation, seals serve to prevent friction within the dynamic-to-static clearances between the main shaft and the casing ends, as well as to prevent steam leakage resulting from pressure differentials inside the casing. The implementation of these measures is critical for improving steam turbine efficiency and ensuring the safe operation of the unit. Steam sealing measures primarily comprise shaft-end seals, flow-path seals, and diaphragm seals.

Design of Flow-Path Seals

Flow-path seals play a pivotal role in the operation of a steam turbine. Situated within the turbine casing-in close proximity to both the rotor and the stationary components-they constitute a critical element in preventing steam leakage. By appropriately designing the geometry and dimensions of these seals, steam leakage within the flow path can be effectively minimized, thereby enhancing the overall efficiency of the steam turbine.