现代煤气化技术作为煤炭资源清洁和高效利用的代表性技术，已经取得了长 足的发展，并日趋成熟和环保。Shell 干粉煤气化技术作为世界上最先进的气流床 技术之一，已经在全世界取得了广泛的应用。本文在 ASPEN PLUS 平台上建立了 Shell 气化炉反应平衡模型，并从熔渣流动特性对气化炉运行的影响出发，研究了 实现有效气产量最大化的操作策略，讨论了 Shell 气化炉运行状态的监控方法，并 对最佳监控参数进行了改进。本论文的主要研究和工作内容如下:1)使用 ASPEN PLUS 平台，借鉴吉布斯自由能最小化方法，建立了 Shell 气化炉反应平衡模型，通过文献数据和现场数据验证了该模型的适用条件。该模型 在气化炉使用 N2 作为煤粉输送载气工况时，能够比较准确地模拟气化炉进料与炉 温和合成气组分之间的关系。2)通过 Shell 气化炉平衡模型，从气化炉最低运行炉温受熔渣流动特性限制 出发，提出了一套确定气化炉运行最佳工况的产率最大四步寻优法，能够针对特 定煤种数据，以最大有效气产率为目标得到最佳氧煤比、蒸汽添加量，进而对有 效气产率与炉温进行预测。工厂运行的实际数据初步验证了该优化策略的适用性。3)分析讨论了气化炉运行状态多种监控参数的优劣和应用场景;基于水汽密 度，对当前行业广泛认可的最佳在线监控参数(气化炉热负荷)的计算方法进行 了改进。现场实际运行结果表明，改进的计算方法能够有效地消除因锅炉循环水 非饱和度导致的计算误差，比原计算方法更为准确;能够消除蒸汽管网压力波动 对计算的影响;与原蒸汽产量的测点相比，密度测点的位置更靠近气化炉反应室 出口，进而提高了热负荷的响应速度。本文能够为 Shell 气化炉运行监控提供优化策略，在保证气化炉安全稳定运行 的基础上，进一步提高了运行效益。
As a representative technology for the clean and efficient utilization of coal, modern coal gasification technology has made considerable improvement, and becoming more and more mature and environment friendly. Shell dry-feed coal gasification technology was one of the most advanced entrained-flow gasification technologies, and has been widely used all over the world. In this thesis, the reaction equilibrium model of Shell gasifier was established on ASPEN PLUS platform. From the influence of slag flow characteristics on the operation of gasifier, the operation strategy to maximize effective syngas production was studied, the monitoring methods for Shell gasifier operation status were discussed, and the optimal monitoring parameter was optimized.Some main works in this thesis are given as follows:1) Using the ASPEN PLUS platform and the gibbs free energy minimization method, the reaction equilibrium model of Shell gasifier was established. The applicable conditions of the model were verified by literature data and field data. It is concluded form the verification that the model can accurately simulate the relationship between gasifier feed, reaction temperature and syngas composition.2) Based on the Shell gasifier reaction equilibrium model, considering the minimum operating temperature constrained by slag fluidity characteristics, a four-step optimization method for gasifier optimum operation condition was proposed. The maximum effective syngas production for certain coal type can be achieved by the optimum oxygen coal ratio and steam addition flow. In addition, it can be used to further predict effective gas production and gasifier temperature. The applicability of the optimization strategy is preliminarily verified by the actual plant operation data.3) The advantages and disadvantages of various monitoring parameters for the gasifier operating condistion and the application scenarios were analyzed and discussed. Based on the water/steam density, the calculation method of the best on-line monitoring parameter (Gasifier Heat Duty), which is widely recognized in the industry, is improved. The plant operation data show that the improved calculation method can effectively eliminate the calculation error caused by the non-saturation of bolier circulating water, and it is more accurate than the original one. It can eliminate the influence of pressure fluctuation from steam network on calculation. Compared with the original steam measurement point, the density measurement point is closer to the gasifier reaction chamber outlet, thus the response speed of gasifier heat duty has been improved.This thesis can provide optimization strategy for Shell gasifier operating and monitoring, and further improve operation efficiency on the basis of ensuring safe and stable operation of the gasifier.
