摘要
为进一步提升燃煤机组的运行灵活性并实现燃煤机组与电力系统的热电解耦,针对燃煤-熔盐耦合系统中储热换热器的优化设计问题展开研究。基于新型模块化熔盐储热换热器的结构特点和实际运行工况中的现场测量数据,计算得出熔盐侧换热系数并对汽水系统的流动传热特性进行计算分析。基于流动网格系统法将汽水管束进行划分并建立流量分配和压降计算模型,将熔盐泵启动工况下实际测量的运行数据与程序计算得出的系统总压降进行对比,相对误差为2.13%,验证了计算模型的可靠性。计算分析了设计工况下汽水系统的压力分布、流量分配、出口汽温、管壁金属温度等特性参数,并进行热负荷受到扰动时的流动不稳定性研究。结果表明:设计工况下熔盐泵不启动时,工质出口汽温为327.7℃;熔盐泵启动时,工质出口汽温为362.2℃;两种运行工况下系统总压降与最大管壁金属温度均在安全合理的范围内,且不会发生流动不稳定的现象。该研究全面评价了熔盐储热换热器运行时的安全性与可靠性,为耦合燃煤发电的熔盐储能技术提供了理论基础。
In order to further enhance the operational flexibility of coal-fired units and to realize the thermo-electric decoupling of coal-fired units from the power system,the optimal design of heat storage heat exchanger in coal-fired molten salt coupling system is studied.Based on the structural characteristics of a novel modular molten salt thermal energy storage heat exchanger and field measurement data from actual operating conditions,the heat transfer coefficient on the molten salt side is calculated and the flow and heat transfer characteristics of the steam-water system are analyzed.Utilizing the flow network system method,the steam-water tube bundle is divided and a flow distribution and pressure drop calculation model is established.Actual operational data measured during the molten salt pump startup condition are compared with the total pressure drop obtained from the program calculations,resulting in a relative error of 2.13%,which verifies the reliability of the calculation model.The pressure distribution,flow distribution,outlet steam temperature,and pipe wall metal temperature under design conditions of the steam-water system are calculated and analyzed,along with a study on flow instability when thermal load disturbances occur.The results indicate that,under design conditions,when the molten salt pump is not started,the working fluid outlet steam temperature is 327.7℃;when the molten salt pump is started,the outlet steam temperature is 362.2℃.The total pressure drop of the system and the maximum metal wall temperature under both operating conditions are within safe and reasonable ranges,and no flow instability occurs.This comprehensively evaluates the safety and reliability of the molten salt thermal storage heat exchanger during operation and provides a theoretical basis for the molten salt energy storage technology coupled with coal-fired power generation.
作者
宋园园
周科
鲁晓宇
李明皓
卫子钰
杨冬
SONG Yuanyuan;ZHOU Ke;LU Xiaoyu;LI Minghao;WEI Ziyu;YANG Dong(State Key Laboratory of Multiphase Flow in Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an 710054,China)
出处
《西安交通大学学报》
北大核心
2025年第7期118-128,共11页
Journal of Xi'an Jiaotong University
基金
国家重点研发计划资助项目(2022YFB4100303)。
关键词
熔盐储热换热器
熔盐侧换热系数
流量分配
压降计算
molten salt heat storage heat exchanger
molten salt side heat transfer coefficient
flow distribution
pressure drop calculation
作者简介
宋园园(1998-),女,硕士生;通信作者:杨冬,男,教授,博士生导师。
