ENHANCEMENTS TO THE LOAD ACCEPTANCE AND REJECTION CAPABILITY OF A HIGH PRESSURE AERODERIVATIVE ENGINE

摘要

This paper describes improvements to the control of a high pressure, aeroderivative industrial gas turbine in order to better accommodate rapid load changes. In such circumstances it is important to maintain the speed of the driven equipment within an acceptable range. This can require the gas turbine to quickly adjust to the new load, to minimize the power imbalance, which is the cause of the speed variation. The paper describes the theory behind control schedules required to achieve this, and how they relate to avoiding surge, flameout or instability, while minimizing speed variations of the driven equipment. A whole engine thermodynamic model coupled to the control software was used to simulate the engine response during these rapid transients. The features of this model are described. The model allowed optimization of the control software in advance of the engine test. Results of whole engine tests are presented and compared to the model; and the types of load steps that remain most challenging are highlighted. The resulting capability remains partly determined by the specifics of the application, for example the inertia of the driven equipment, the nominal speed of operation, and the allowable speed variations. The effects of these can be predicted using the model and are discussed.