【摘要】 采用滑压运行方式，在180～300 MPa工况范围内，对某600 MW超临界锅炉深度调峰不同负荷工况下的前包墙壁温脉动特性进行了试验研究。根据试验数据分析了低负荷工况与壁温脉动的影响，并采用光镜、扫描电镜及机械性能试验分析了前包墙管脉动性超温下的外径蠕变与组织、力学性能变化关系。结果表明：在深度调峰低负荷工况下，受热面管壁温脉动周期及脉动振幅随负荷降低而增大，热负荷愈高，壁温脉动振幅愈高；当低于临界负荷运行时，受热面管内工质传热恶化，受热面管壁温脉动周期及振幅显著增大，热负荷高区域受热面管脉动性运行超温，使受热面管外径蠕变增大、材质组织球化、性能劣化而最终导致爆管。更多还原

【Abstract】 The fluctuation characteristics of the front wall superheater of a 600 MW supercritical boiler under different load conditions during deep peak shaving were experimentally investigated under the operation mode of sliding pressure, load operation from 180 MW to 300 MW. According to the experimental results, the effect of load conditions and wall temperature fluctuation was analyzed, and by means of optical microscopy and scanning electron microscopy, and mechanical property tests, the relationship between outer diameter creep and changes in microstructure and mechanical properties of the front wall tube under pulsating overtemperature condition was analyzed. The results show that under deep peak shaving and low load conditions, the fluctuation period and amplitude of the wall temperature of the heating surface tube increase with the decrease of load. The higher the heat load, the higher the wall temperature fluctuation amplitude. When operating below the critical load, the heat transfer inside the heating surface tube deteriorates, and the wall temperature fluctuation period and amplitude of the heating surface tube significantly increase. In areas with high heat load, the pulsation operation of the heating surface tube exceeds the temperature, leading to an increase in the creep of the outer diameter of the heating surface tube, spheroidization of the material structure, performance degradation and ultimately leads to tube blasting.更多还原