Performance Modeling of New and Existing Steam Turbines

Abstract

This work investigates the effect of structural parameters (turbine size and type) and operating parameters (inlet steam temperature and pressure, steam flow rate, single or multistage exhaust rate, and pressures) on turbine performance for power generation. The paper extends the steam turbine performance model based on the Willans line. The model achieves high accuracy for a wide range of steam turbines at full-load and part-load operation, which has been verified against data for commercial turbines and from the available literature. The correlation of turbine efficiencies provides realistic insights from the model. The model can be applied in utility system design, operational optimization, and system retrofit with complex multistage turbines. For existing turbines, adjustment of operating conditions and steam header conditions can be explored. This overcomes problems from previous correlations, which did not account for changes in steam main pressures. Regression of coefficients from existing turbine operating data can be used to give better performance prediction for existing turbines, allowing more effective system optimization.

Steam storage systems for flexible biomass CHP plants - Evaluation and initial model based calculation

“…To calculate the turbine performance the modelling approach of Sun & Smith is applied [17]. Their equations can be used to calculate the part-load behaviour and are validated for small scale turbines.…”

“…Typically, the mechanical efficiency is in the range of 0.97 and 0.99 and is not significantly impacted by partload operation [17], whereas the isentropic efficiency is highly load-dependent.…”

“…The main parameters influencing the efficiency, especially the part load efficiency, of a steam turbine are the type of the turbine (back-pressure or extraction), the turbine dimensions, the maximum electrical performance, the inlet pressure and temperature, the outlet steam pressure and the operating load (part-load conditions) [17].…”

“…The equations for the slope n (Equation 5) and the intercept WINT (Equation 6) of the Willan's line are based on the design mass flow (maximum mass flow) m;˙max and the model coefficients a, b and c. The Willans line is a common approach for the calculation of the part-load behaviour of steam turbines [17].…”

Development and optimization of a novel process of double‐effect distillation with vapor recompression for bioethanol recovery and vapor permeation for bioethanol dehydration

“…This is considering turbine capacity (of 2-4 MW) and based on efficiency ranges in Branan 34 and Sun and Smith. 39 Branan 34 states that steam turbine efficiency ranges from 42 to 78%. Sun and Smith 39 state that a large steam turbine (>8 MW) has high efficiency (65-90%) compared with 50% efficiency of a small turbine (<8 MW).…”