This paper describes the experimental results of both steady and unsteady flow behavior and surge extension with steam injection in a centrifugal compressor with vaned diffuser and downstream collector. Specifically, the stage stability analysis and effects of steam injection on surge margin are reported based on experimental results in detail.
As the first step, a meanline analysis based on empirical correlations is utilized to find the possible stability dominated component. Then surge extension methods are put forward on the investigated compressor to enhance field operability.
To validate the meanline analysis, the static performance of both stage and components from the experiments were analyzed and the root cause of system surge was again given based on the classic stability theory.
The experimental results not only prove the validity of the former stability analysis but also extend the surge margin at least 9.0% with only 0.3% saturated steam of designed mass flow rate. During the experiments, it was also found that the surge margin improvement was not in proportion to the flow injected. In certain cases, the injected steam at large flow rate can even trigger system surge earlier.
To the authors’ known, this is the first report on surge extension with steam injection in open literature.
Set-Based Tasks within the Singularity-Robust Multiple Task-Priority Inverse Kinematics Framework: General Formulation, Stability Analysis, and Experimental Results