A novel system for reducing power plant electricity consumption and enhancing deep peak-load capability

Abstract

Enhancing the operational flexibility of coal-fired power plants is a crucial measure for energy transition. Current heat-power decoupling technologies primarily rely on external heat storage or provision. In order to comprehensively analyze the self-decoupling potential of the units and explore more effective methods to reduce the power plant electricity consumption rate (PPEC), this study proposes an innovative system that utilizes surplus steam from the power plant to drive rotating equipment through multi-stage series-parallel turbines. The study investigates the impact of various steam sources, methods of electrical equipment connection, and exhaust positions on system performance. The results demonstrate that the optimal strategies can lead to an average reduction of PPEC to 2.84%, decrease the power supply coal consumption rate by an average of 12.04 g/kWh, and increase the deep peak-shaving capacity by 35.20 MW during the heating season. During the non-heating season, it can reduce the PPEC by an average of 3.73% and increase the deep peak-shaving capacity by 30.47 MW. The static investment payback period and dynamic investment payback period under the optimal strategy are 5.15 years and 6.09 years, respectively. This research presents a promising approach to enhancing the flexibility of thermal power units by utilizing small steam turbines.