Abstract

Few of existing literatures on the airflow distribution of compartments have studied combined applications of radiant heating and air conditioning in winter. Simulation of airflow distribution in 25 T soft sleeper compartments under different heating and ventilation schemes is provided in this paper. Firstly, reliability of the numerical simulation model has been verified by the experimental data in the literature, and the appropriate turbulence model has been selected. Afterwards, numerical simulations are carried out on airflow distribution in those compartments with four ventilation modes under radiant heating conditions in winter. Research results show that as for thermal comfort, task air supply can provide the smallest temperature difference between head and foot positions as well as the best thermal comfort. As for effectiveness of air supply, the ventilation efficiency of louver side air supply is the highest among others. As for effectiveness of pollutant removal, the ventilation efficiency of task air supply is higher than the other three options. These four heating and ventilation schemes are evaluated comprehensively with fuzzy comprehensive evaluation method. Results reveal that task air supply is the mode with best comprehensive performance indices. It is followed, respectively, by louver side air supply, perforated ceiling air supply and louver top air supply.

摘要

现有的关于隔间气流分布的文献很少研究冬季辐射供暖和空调的联合应用。本文提供了在不同加热和通风方案下的 25 T 软卧车厢气流分布的模拟。首先通过文献中的实验数据验证了数值模拟模型的可靠性，并选择了合适的湍流模型。然后，对冬季辐射供暖条件下四种通风模式的车厢内气流分布进行了数值模拟。研究结果表明，对于热舒适性，任务送风可以提供最小的头脚位置温差以及最佳的热舒适性。在送风效率方面，百叶侧送风的通风效率是最高的。至于污染物去除的有效性，任务送风的通风效率高于其他三个选项。采用模糊综合评价法对这四种供暖通风方案进行综合评价。结果表明，任务送风是综合性能指标最好的模式。随后分别是百叶侧送风、穿孔天花板送风和百叶顶部送风。采用模糊综合评价法对这四种供暖通风方案进行综合评价。结果表明，任务送风是综合性能指标最好的模式。随后分别是百叶侧送风、穿孔天花板送风和百叶顶部送风。采用模糊综合评价法对这四种供暖通风方案进行综合评价。结果表明，任务送风是综合性能指标最好的模式。随后分别是百叶侧送风、穿孔天花板送风和百叶顶部送风。