Methodology for the thermodynamic optimization of steam turbine pump performance

Pumps are an integral part of steam-driven turbines since they are necessary to provide continuous kinetic energy to the working fluid and operate at considerably high pressures to meet boiler design conditions. Thermodynamic modeling and optimization from an energy viewpoint will establish the link between optimum operating conditions concerning boiler design. This was achieved through thermodynamic modeling and optimization of pump performance on a steam-driven turbine rated at 50 MW. Using developed energy models, a system performance simulation was made by systematically accounting for the variation in pump efficiency and overall turbine output. For the considered pumps, overall cycle thermal efficiency is slightly affected by the pump performance efficiency even at higher pressures. Increasing pump efficiencies has been shown to improve overall cycle efficiency comparatively. The system recorded 80 % pump efficiency, 640 K temperature at the WHRB, 35 bar pressure at the inlet to the turbine, and a steam mass flow rate of 50.6 kg/s, respectively. The system's thermal efficiency was 38.39 % finally. Furthermore, in cases where a tradeoff between cycle performance, efficiency, and cost of operation is required, these results will be helpful in the multi-objective optimization of similar systems in cost and thermal efficiency.