The classic Xiao kinetic mechanism suffers from insufficient prediction accuracy and excessive computational cost when conducting numerical simulations of micro gas turbine combustors fueled with ammonia/hydrogen blends.To address these drawbacks,this paper simplifies and optimizes the original Xiao mechanism by combining numerical simulation with sensitivity analysis,and develops a reduced kinetic model M-3 capable of accurately calculating the combustion characteristics of ammonia/hydrogen mixtures.The reliability of the M-3 model for numerical simulation of practical gas turbine combustors is verified via micro gas turbine tests.The results demonstrate that the M-3 model achieves substantially improved calculation accuracy compared with the Xiao mechanism.Its calculation errors of laminar burning velocity and ignition delay time are 9.38%and 25.91%,representing accuracy improvements of 61.63%and 65.19%relative to the Xiao mechanism,respectively.Although the ignition delay prediction error of the M-3 model is 6%higher than those of the Zhang and Glarborg mechanisms,the overall size of the model is reduced by approximately one-third,which greatly shortens the computation time of numerical simulations.Furthermore,the influence of hydrogen blending ratio on combustion characteristics is investigated.Numerical results of the gas turbine combustor indicate that the temperature and NOX distributions predicted by the M-3 model agree well with practical expectations.In contrast,the Xiao mechanism underestimates the combustor temperature and overestimates NOX emission concentrations.The proposed M-3 model can provide robust kinetic support for the research and application of ammonia/hydrogen blends in gas turbines.
采用自主搭建的烟尘罩烟气采集系统及沉降炉实验台,对典型农林废弃物水稻、小麦、玉米和杨木进行露天焚烧、家用炉灶燃烧和工业锅炉燃烧实验,测定不同燃烧条件下的颗粒物及气态污染物排放因子.结果表明:CO、颗粒物排放因子对燃烧条件较为敏感,与MCE值存在良好的相关性.三种燃烧方式颗粒物排放因子大小排序为露天焚烧＞家用炉灶＞工业锅炉.颗粒物和CO排放因子随燃烧温度的上升,过量空气系数的增大,含水量的减小而减小,且堆垛时大于平铺时.当燃烧状态趋于恶劣时,燃烧会倾向于生成较大粒径颗粒物(粒径＞1μm).在工业锅炉实验设定工况范围内,温度对CO排放因子的影响最大,过量空气系数次之,含水量最小.
为解决某电厂送风机中的新型锻铝 2A50 材质动叶片在投运后短期内频繁出现断裂的问题,从制造、安装、运行阶段入手,通过现场检查、监测运行数据、化学成分分析、硬度测试、室温拉伸试验、显微组织及断口形貌观察等手段,对叶片断裂原因进行了综合分析.结果表明:叶片断口整体呈现疲劳断裂特征,本身的抗疲劳强度不足是造成叶片断裂的主要原因;叶片化学成分、硬度、力学性能均能满足要求,但叶片边缘存在晶间裂纹和凹坑等缺陷;叶片在表面缺陷处过早地形成疲劳裂纹源,加之进气边被冲刷减薄,导致叶片断裂失效.
考虑到风电场功率分配存在功率跟踪精度差、波动剧烈和变桨机构动作频繁等问题,提出一种加入信息熵权值设置的FCM聚类算法来对风电场内机组进行分类,并以此为基础对风电场有功功率分配进行优化.采集风电场和调度中心的实时运行数据,选择风电机组的实时出力、实时风速、转速和桨距角作为聚类指标.运用熵权法对各指标进行权重设置,以此为基础对风电机组进行FCM聚类,再进行有功功率分配.以Matlab/Simulink 中的SimWindFarm工具箱为平台,对 12 台风电机组进行有功功率分配仿真研究.通过与传统有功功率分配算法相比较,仿真验证所提分配算法可以有效提高功率跟踪精度、减小波动及机组动作次数.
针对某沿江火力发电机组凝汽器换热管束受贝类堵塞和泥沙沉积,造成凝汽器胶球清洗效果不佳的问题,在对原凝汽器进口水室和出水侧的在线清冲洗装置机械臂进行优化设计的基础上,应用凝汽器在线水冲洗装置解决了凝汽器换热管束受粘泥、贝类杂物阻塞的问题.试验验证得出,改造后凝汽器真空提高约 0.16kPa,具有较好的节能效果,相比于胶球单独清洗,能够更好地清洗凝汽器中的粘泥、贝类等杂质,对于维持凝汽器清洁系数和换热管束的通透率具有较好的效果.
