文档介绍：题目:超超临界锅炉垂直管屏水冷壁流量补偿特性研究
英文题目:Characteristics Study for Ultra-supercritical Boilers with Vertical Rifled Tube Platen Water Wall on pensation
摘要
对超超临界锅炉内螺纹管垂直管屏水冷壁变压运行时的流量补偿特性进行了理论分析。以1000MW超超临界锅炉垂直管屏水冷壁设计参数为依据,编制了流量补偿特性计算程序,对该锅炉水冷壁在不同热负荷和热偏差条件下,不同质量流速下的流量补偿特性进行了分析研究。验证了直流锅炉水冷壁系统在高负荷区高质量流速条件下具有强制流动特性,在低负荷区低质量流速条件下具有自然循环的自补偿特性,这种特性对实现直流锅炉变压运行具有重要作用,但增加了由自补偿特性向强制流动特性转化的复杂性。论文计算并分析了锅炉水动力特性,验证了水动力单值性。分析了热负荷、管子内径、管子根数对压降的影响。研究结论可供UP型超临界直流锅炉运行和设计参考。
关键词:超超临界锅炉;热偏差;流量补偿;垂直管屏;下辐射区水冷壁
ABSTRACT
The variable pressure operation characteristic of ultra-supercritical boiler with vertical rifled tube platen water wall is analyzed in this paper. Based on the designed data of vertical tube water wall in a 1000MW supercritical boiler and regarding to the hydrodynamic calculation method, a calculation procedure of pensation characteristics is established. The pensation characteristics in the condition of different loads and mass flow rates are analyzed and studied, therefore it validates that direct current boiler has not only direct current characteristics but also natural circle characteristics like drum boiler’s which play the important role in the variable pressure operation. Hydrodynamic characteristic of boilers is calculated and analyzed and uniqueness of hydrodynamic is validated. Also the effects between heat load and drop, tube
’s inner diameter and drop, tube’s number and drop are analyzed.
Wang Xue-tao(Thermal Power Engineering)
Directed by prof. Fan Quan-gui
KEY WORDS: ultra-supercritical boiler,heat deviation,pensation,vertical tube platen,water wall’s lower radiation
第一章引言
课题研究的背景及意义
能源是社会发展的物质基础,环境是人类维护自身生存和发展的前提。在能源日趋紧张,环境日益恶化的情况下为节约能源和减轻环境污染,必须发展洁净煤发电技术[1],即:循环流化床(CFBC)、增压流化床联合循环()、整体煤气化联合循环()以及超临界(SC)与超超临界技术(USC)。
超临界机组是指发电机组的蒸汽参数达到临界压力以上的机组。目前,世界上超临界机组的蒸汽参数以24MPa 、540℃/540℃为基础。超超临界机组并没有严格的定义,国际上通常把主蒸汽压力在27MPa以上或主汽、再热汽温在580℃以上的机组定义为超超临界(USC)机组[2]。超超临界机组正是由于提高了锅炉蒸汽的初参数,使得机组效率大大提高,达到45%~48%,比亚临界机组提高6%~9%,比超临界机组高3%~4% 。尽管在同等蒸汽参数情况下,联合循环的效率比蒸汽循环的效率高10%左