超超临界汽轮机中压缸冷却技术研究进展

Research Status of Cooling Technology for Intermediate Pressure Cylinder of Ultra-Supercritical Steam Turbines

超超临界汽轮机中压缸采用蒸汽冷却技术,能够改善进口高温部件的工作环境,降低其热载荷。冷却技术与先进耐高温材料配合使用,能够实现主蒸汽参数进一步向高超超临界水平发展。简要介绍了中压缸冷却技术的工作原理、特点和意义,以及共轭传热技术的引入对冷却技术研究的推动作用,重点讨论了不同冷却技术的研究进展和现状,在此基础上详细分析了冷却蒸汽来源和进汽方式、冷却蒸汽进口参数、冷却结构设计等因素对冷却效果的影响。提出在继续深入研究冷却机理和结构优化的同时应当开展流-热-固多物理场耦合研究,以更加准确深入地把握冷却方案对部件的运行安全可靠性和寿命的影响。

The steam cooling technology is used in the intermediate pressure cylinder of ultra-supercritical steam turbines. The working environment of the high temperature components can be improved and the corresponding thermal loads can be reduced by means of steam cooling technology. Furthermore, the development of the main steam parameters towards advanced ultra-supercritieal level can be realized through the combination employment of the cooling technology and heat-resist materials. In the aim of this research, the working principles, characteristics and significance of the intermediate pressure cylinder cooling are briefly introduced, and the promotion effect of the conjugate heat transfer methodology on the cooling technology is indicated. The research status and progress of different cooling technologies is emphatically discussed, and on the basis of the above, the impact of cooling steam source, inlet structure, parameters of cooling steam and cooling structures on the cooling effectiveness is analyzed in detail. The investigation for flow-thermal-solid multiphysies is recommended based on the study of cooling mechanisms and structure optimization, so as to accurately understand the effect of the cooling plan on the operation safety and life of high temperature components.