Abstract:
Supercritical carbon dioxide (S-CO
2) cycle has been shown to have compact size and fast response to external load variation. Small-scale capacity coal-fired S-CO
2 power plant can be used as the regulating heat source in distributed energy systems. The objective of this paper is to construct the small-scale coal-fired S-CO
2 power plant. The construction roadmap is proposed as follows. 1) Cycle configuration is selected by considering efficiency and technical economy. 2) The optimal main vapor pressure is selected by the sensitivity analysis of cycle efficiency with the pressure. 3) Considering the overheating of boiler components, the main vapor temperature is selected at the material boundary conditions frequently-used in steam boilers. Based on the above path, tri-compressions with last-stage partial compression (PTC) are proposed, which are more suitable for coal-fired power plants. And reheating (RH) and PTC are integrated as PTC+RH, which is recommended for demonstration power plants. Then, 25MPa/605℃ are selected as the main vapor parameters. At last, a 50MW coal-fired power plant is given. The power efficiency is 43.91%. The work provides the guideline for the design and operation of small-scale S-CO
2 coal fired power plant.