Abstract: As the key technical means for flexibility retrofitting of the combined heat and power (CHP) units, decoupling of thermal and power generation can effectively improve the peak load regulation ability and heating regulation ability of thermal power plants, thus increasing the flexibility of power supply side. Therefore, decoupling of thermal and power generation is crucial to the power system with a high proportion of renewable energy. This paper reviews the main technical means and development status of decoupling of thermal and power generation, and analyzes operating characteristics of six typical retrofitting technologies. Combining with actual cases, this paper systematically discusses the investment cost, the improvement of peak load regulation ability, the improvement of heating capacity and the impact of energy consumption of these typical retrofitting technologies. The technical and economic effects of different retrofitting technologies on the CHP units are compared from the comprehensive perspective of theory and practice. The influence of different retrofitting technologies on the flexibility of units is emphatically analyzed.
Key words: Decoupling of Thermal and Power Generation; Flexibility; Peak Load Regulation; Heating Capacity