1000MW等级超超临界锅炉张力板结构的强度计算及优化

张力板是锅炉螺旋管圈水冷壁的重要部件,其主要作用是通过槽型钢、张力板、手指板等一系列结构将螺旋管圈荷载传递至垂直管圈。本文利用有限元计算方法,对1000MW等级超超临界n型布置锅炉张力板及手指板结构强度进行计算分析。并根据计算结果,对该结构提出了优化方案。     

The dynamic creep rupture of a secondary superheater tube in a 43 MW coal-fired boiler by the decarburization and multilayer oxide scale buildup on both sides

A dynamic creep mechanism has been proposed and verified through a case study. A secondary superheater tube burst occurred in a 43 MW coal-fired boiler. Microstructural examination indicates that the overheating temperatures reached 900 °C (above Ac3). The overheating duration was estimated to be 3 h by calculating with LMP formula. The 710 μm steam-side scale and 960 μm fireside scale built-up in the short time of overheating. The burst scenario was a short-term severe overheating on the basis of the long-term creep. The multilayer oxide scales on both sides have been studied with ESEM/EDS, indicating FeO. At 900 °C, full decarburization had gone throughout the tube. As the strength reduced due to the decarburization, the creep mechanism transformed from long-term intergranular creep to short-term transgranular rupture. The two types of dimples on the fractograph and two types of cracks in the microstructures confirmed the mechanism transformation. The overheating, the scale buildup and the decarburization constituted the full picture of the dynamic creep rupture.     

关于锅炉节能减排技术及实践的探讨

在国家提倡节能减排的大环境下,特种设备的节能减排形势不容乐观。锅炉作为典型的特种设备,与工业经济息息相关。从工业锅炉的节能减排现状入手,分析目前存在的问题,并且提出了提高能效的措施。     

锅炉传热介质标准体系研究

结合我国对现代环境、安全等各方面的要求,在对我国锅炉传热介质标准的现状及其存在问题进行分析的基础上,提出了建设标准体系的目的、原则及其基本构成等。建立相应的标准体系对促进我国锅炉传热介质安全、经济、节能、环保运行,推动其产业发展,具有重要的现实意义和长远的战略意义。     

Hierarchical optimization of boiler–turbine unit using fuzzy stable model predictive control

This paper develops a hierarchical control system structure based on the Takagi–Sugeno fuzzy model to achieve an optimal control of a boiler–turbine unit. In the upper layer of the hierarchy, an optimal reference governor is designed to find the optimal operating point. A disturbance term is introduced to the fuzzy model to lump the modeling mismatch and unknown disturbance. Thus, the effect of plant behavior variation can be removed and the operating point found can be feasible to control. In the lower layer, a stable model predictive controller is developed to track the optimal set-points while guaranteeing the input-to-state stability of the system. Fuzzy Lyapunov function and appropriate slack and collection matrices are used to reduce the conservatism of stability design and improve the performance. Through the estimation of the disturbance term using an observer, the two layers in the hierarchy are coupled and the integrated system can realize a dynamic optimal control of the boiler–turbine unit, even in the case of severe plant behavior variations.     

Sizing of Packed Deaeration Columns

Removal of oxygen from feedwater is of paramount importance for safe boiler operation. Insufficient extraction of oxygen in deaeration vessels will lead to limited efficiency of oxygen scavengers and unsafe plant operation. The presented sizing procedure for packed deaeration columns is based on the similarity theory between heat and mass transfer and existing procedures. The goal of the proposed technique is not to achieve optimization of column dimensions, but to ensure that there is no undersizing of the packing height. This approach is justified considering the relatively low capital costs of deaeration columns in boiler plants. The proposed equations are based on an experimental setup involving several hundred operating regimes which have been verified and confirmed to have a high degree of accuracy.     

10MW级高压变频器在合成氨装置主机系统中的应用分析

本文通过对现有40万t合成氨装置主压缩杌组驱动系统分析，指出了其中存在的问题。针对性提出采用电气驱动替代“锅炉＋汽轮机”驱动的新思路：通过对两种驱动形式的经济性比较，技术可行性分析，阐述了该新型驱动形式的可行性和良好应用前景。     

660MW四角切圆锅炉混煤燃烧数值模拟分析

为了优化煤粉燃烧,提高电厂效益,以660MW超超临界四角切圆锅炉作为研究对象,利用CFD数值模拟方法对该锅炉混煤燃烧状态进行模拟分析。通过对多种掺混比例沿炉膛高度方向O2浓度、NOX浓度、CO2浓度等云图分布,对比分析了炉内燃烧状态。结果表明,在设计煤种与现有煤种掺混比例为4:1时,NOX浓度在炉膛中心明显增加,O2浓度在三种掺混方式下分布较为接近。在距一次风喷口较近区域,CO2的浓度相对较少;在壁面处,部分煤粉颗粒流动受阻,局部CO2变高。对比分析确定了该锅炉掺混的最佳比例,对合理选择煤种配比提供参考。     

基于物联网的锅炉能效测试集成系统的研发

基研发了一种基于物联网的锅炉能效测试集成系统。该系统以物联网为网络技术架构、以Zigbee为无线通讯技术，高度集成化测试设备，完全实现了现场测试数据自动采集、无线传输、记录和处理等功能，可现场出具测试报告等功能，可极大地减少测试人员的劳动强度，提高工业锅炉能效测试的科学性和可信度。     

Erosion–corrosion behaviour of Ni–20Cr plasma coating in actual boiler environment

Abstract

Erosion–corrosion is encountered in a large variety of engineering industries. In such environments, protective coatings are used. In this investigation, erosion–corrosion of the Ni–20Cr coating on nickel and iron based superalloys has been investigated by subjecting them to the boiler of coal fired thermal power plant at the temperature zone of 540°C for 1000 h duration. The erosion–corrosion kinetics of the plasma sprayed Ni–20Cr coating on different superalloys has been investigated. XRD, SEM with EDS and EPMA have been used to analyse the eroded–corroded products along the surface and cross-section. Main phases identified in all the Ni–20Cr coated superalloys after exposure are NiO, Cr₂O₃, Al₂O₃ and SiO₂. Aluminium has penetrated from the bond coat to the top coat along the splat boundaries. Oxides of chromium, nickel and aluminium are recognized as protective oxides for boiler environment. The probable mechanism of attack for Ni–20Cr coating in the given boiler environment is discussed.