Abstract This paper describes the development and validation of a numerical tool able to simulate biomass combustion in grate-fired systems and support operation and design improvements of these devices. The modeling method is conceived as a compromise between the demand of computing time and the degree of detail in the simulation. As such, it integrates both the bed zone and the freeboard zone on a same 3D grid and assumes the bed as a porous medium, where heterogeneous reactions are simulated by a modified laminar rate model. Liquid water, dry biomass and char are introduced as site species that react on the porous medium surfaces to produce and/or consume gas species (O2, CO, CO2, H2, H2O, light hydrocarbons and condensable gases). To validate the numerical tool, predictions have been compared to experimental data gathered in a 250 kWth combustion test facility operated with a high quality woody pellet. Once validated, the tool has been applied to characterize the flow patterns as well as the temperature and the main gaseous emissions profiles within the combustion chamber. According to the analysis of the simulation results, significant improvements have been identified concerning not only operation but also design issues.

中文翻译：

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通过基于 CFD 的简化方法对炉排生物质锅炉进行有效诊断

摘要 本文描述了一种数值工具的开发和验证，该工具能够模拟炉排燃烧系统中的生物质燃烧，并支持这些设备的运行和设计改进。建模方法被认为是计算时间需求和模拟细节程度之间的折衷。因此，它将床区和干舷区集成在同一个 3D 网格上，并将床假定为多孔介质，其中非均相反应通过改进的层流速率模型进行模拟。液态水、干生物质和炭被引入作为在多孔介质表面上反应以产生和/或消耗气体物种（O2、CO、CO2、H2、H2O、轻质烃和可冷凝气体）的现场物种。为了验证数值工具，已将预测与在使用高质量木质颗粒运行的 250 kWth 燃烧测试设施中收集的实验数据进行了比较。经验证后，该工具已被用于表征燃烧室内的流动模式以及温度和主要气体排放分布。根据对仿真结果的分析，不仅在操作上，而且在设计问题上都发现了显着的改进。