Development of Multi-layer Zone Smoke Transport Computer Model

传统上，建筑物的消防安全设计是由建筑物和消防法中规定的规定来指导的。然而，近年来，随着消防安全工程的显著进步和基于性能的消防安全设计实践的全球趋势的发展，对更合理和更具成本效益的设计的需求越来越强烈。值得注意的是，“两层区域模型”和“CFD模型”等火灾模型在新的火灾设计实践中发挥了重要作用。前者通过考虑建筑物每个房间的上层和下层作为控制体积来预测烟雾传输的火灾物理行为，由于其计算负担不高，尽管它只能预测两层的平均物理性质，但在消防安全设计实践中最受欢迎。另一方面，后者在详细研究火灾行为方面更为强大，因为它可以提供大量的火灾现象信息，尽管它的计算要求很高。本课题提出了一种基于多层概念的烟气输运模型。它可以提供比两层带模型更详细的信息，如室内温度和物种浓度的垂直分布以及天花板喷射温度，同时保持两层带模型在计算时间和数据输入方面的低要求。在这个模型中，建筑中的每个房间都被划分为任意数量的水平层。以每一水平层为控制体，建立了模型的公式集，并建立了计算机模型，对模型进行了数值计算。顺便说一句，在这个模型中，火羽继续上升，直到击中房间天花板，而不是像现有的两层区域模型中假设的那样，在火羽的上层均匀混合。将多层带模型的预测结果与本项目中进行的全尺寸火灾试验结果和现有的一些试验结果进行了比较，结果吻合较好。该模型可作为新一代烟气输送模型的候选模型，应用于实际建筑的消防安全设计。少

Traditionally, fire safety designs of buildings have been guided by prescriptive provisions set out in building and fire service laws. Recent years, however, demands for more rational and cost-effective designs have become stronger reflecting the notable progress in fire safety engineering and worldwide trend of performance-based fire safety design practices have developed. It is noted that fire models such as 'two layer zone models' and 'CFD models' have played a great role in the new fire design practices. The former, which predicts fire physic behavior of smoke transport by considering an upper and lower layers in each room of a building as control volumes, have been most popular in fire safety design practices because of its undemanding computational burden although it can only predict average physical properties of the two layers. On the other hand, the latter have been more powerful to investigate fire behavior in detail because it can give a great amount of information on fire p … More henomena although its computation is significantly demanding.In this project, a new smoke transport model was developed based on multiple layer concept. It can give more detailed information than two layer zone models such as vertical distributions of temperature and species concentrations in rooms and ceiling jet temperature while maintaining the undemanding nature of two layer zone models in computational time and data input. In this model, each room in a building is divided into arbitrary number of horizontal layers. The physics relating smoke transport were mathematically modeled letting each horizontal layer as a control volume to establish a formula set of the model and a computer model was developed for numerical computation of the model. Incidentally, the fire plume in this model continues to rise until hitting room ceiling unlike the uniform mixing in the upper layer of a fire plume assumed in the existing two layer zone models. The predictions by the multi-layer zone model were compared with the results of a full-scale fire test conducted in this project and some of the existing experiments with satisfactory agreement. This model is evaluated to be a potential candidate of new generation smoke transport to be used in fire safety designs of actual buildings. Less