Performance analysis of turbine extraction superheat utilization schemes of built power plant

Abstract

The system optimization scheme of adopting outer steam coolers (OSCs) to utilize turbine extraction superheat (conventional scheme) is considered an effective way to improve the thermal efficiency of power plants. However, adopting the conventional scheme in a built unit would increase the feedwater temperature, thus generating under-temperature reheat steam for some units. A novel system optimization scheme was proposed with turbine extraction for preheating feedwater and cold reheat steam simultaneously. Case analysis shows that the proposed scheme attains a better energy-saving effect than the conventional scheme under the considered load conditions. The investment payback period (IPP) of the novel scheme is 3.98 years, which is better than the attained 6.93 years of the conventional scheme.

Keywords

• Steam superheat utilization
• System optimization
• Reheat steam
• Temperature adjustment