耦合熔盐储热的超临界二氧化碳循环系统变负荷发电效率提升方法  

Method for Enhancing Load-Following Power Generation Efficiency of SCO_(2) Cycle Systems Coupled with Molten Salt Thermal Energy Storage

作　　者：蒋睿 李明佳 马腾[1] 杜燊 章子训 JIANG Rui;LI Mingjia;MA Teng;DU Shen;ZHANG Zixun(National Innovation Platform(Center)for Industry-Education Integration of Energy Storage Technology,Xi’an Jiaotong University,Xi’an 710049,China;School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]西安交通大学国家储能技术产教融合创新平台(中心),西安710049 [2]北京理工大学机械与车辆学院,北京100081

出　　处：《西安交通大学学报》2024年第12期11-21,共11页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金重大资助项目(52293413);国家自然科学基金资助项目(52341601)。

摘　　要：针对非设计工况下超临界二氧化碳(SCO_(2))循环发电效率大幅度降低,系统运行经济性下降的问题,提出了一种SCO_(2)循环系统变负荷发电效率提升方法。该方法在系统设计方案上,采用多个小容量机组代替传统的单一大容量机组;在运行模式上,采用多机组之间串并联相结合的运行模式。通过建立耦合熔盐储热的SCO_(2)循环系统实时动态模型,对比了多机组方案和传统单一机组方案的变负荷发电效率、调峰范围以及运行经济性,计算结果表明:对于额定功率为300 MW的单一机组,当输出功率从额定功率降低至20%额定功率时,其发电效率将从55.01%降低至21.97%;以串并联相结合模式运行的多机组方案相比于单一机组,在全工况范围内可将效率平均提高7.92%,同时可将调峰范围由100%~20%额定功率扩大至100%~3.33%额定功率;在参与调峰时,多机组方案相比于传统单一机组可节省12%的热盐消耗量。所提SCO_(2)循环系统变负荷提效方法对提高电站发电效率和运行经济性具有参考价值。To address the significant reduction in power generation efficiency and operational economy of supercritical carbon dioxide(SCO_(2))power cycle systems under off-design conditions,a method for enhancing the load-following power generation efficiency of SCO_(2) cycle systems is proposed.In the design scheme,multiple small-capacity units are employed instead of a single large-capacity unit.In the operational mode,a combination of series and parallel operation among multiple units is utilized.By establishing a real-time dynamic model of an SCO_(2) cycle system coupled with molten salt thermal energy storage,a comparison is made between the multi-unit scheme and the traditional single-unit scheme in terms of load-following efficiency,peak shaving range,and operational economy.The results indicate that for a single-unit system with a rated power of 300 MW,when the output power is reduced from the rated power to 20%of the rated power,the efficiency decreases from 55.01%to 21.97%.The multi-unit system operating in a series-parallel combination mode can increase efficiency by an average of 7.92%and expand the peak shaving range from 100%to 20%of the rated power to 100%to 3.33%of the rated power.Furthermore,when applied to peak shaving,the multi-unit system can save 12%of molten salt consumption compared to the traditional single-unit system.The proposed method for enhancing load-following efficiency of SCO_(2) cycle systems provides valuable insights for improving the generation efficiency and operational economy of power plants.

关 键 词：超临界二氧化碳循环 熔盐储热 变负荷发电效率 多机组方案 

分 类 号：TK123[动力工程及工程热物理—工程热物理]