某制冷机房氨气泄漏时气流组织优化分析

Optimization of Air Flow Pattern for Leakage of Ammonia Gas in a Refrigerator Room

本文针对氨制冷压缩机低压吸气管道破裂后氨制冷剂泄漏的场景,采用计算流体力学(CFD)的方法对不同气流组织下事故通风过程进行了数值模拟,对比了不同气流组织下的事故通风有效性。计算结果表明:侧墙排风口上沿距顶在0~0.2 m范围内对污染物排除几乎没有影响。在氨制冷机房两端有门,中部有上、下两排窗的情况下,对于通风120 s后NH3质量分数超过4.2×10-4区域的体积,相比于开全部窗的工况,开全部门工况该区域体积高出133.0%,开全部窗和门工况该区域体积高出60.7%,开上排窗的工况该区域体积降低98.1%,开下排窗的工况室内该区域体积高出180.3%。对于通风120 s后的室内NH3总质量,相比于开全部窗的工况,开全部门工况高出40.6%,开全部窗和门工况高出12.7%,开上排窗的工况降低24.1%,开下排窗的工况高出44.4%。

To exhaust the ammonia gas released after the rupture of a low-pressure suction pipe of an ammonia refrigeration compressor,a computational fluid dynamics(CFD)method was used to numerically calculate the accident ventilation process and compare the emergency ventilation effectiveness under different airflow patterns in this study.According to the calculation results,the upper edge of the exhaust vent in the side wall has little effect on the removal of pollutants within the range of 0-0.2 m.When there are doors at both ends of the ammonia refrigeration plant,and there are upper and lower rows of windows in the middle,,the volume of the area where the NH3 mass fraction exceeds 4.2×10-4 after 120 s of emergency ventilation is:133.0%higher with all doors open,60.7%higher with all doors and windows open,98.1%lower with the upper row of windows open,and 180.3%higher with the lower row of windows open respectively than that with all open windows.The total indoor NH3 mass after 120 s of ventilation is 40.6%higher with all doors open,12.7%higher with all windows and doors open,24.1%lower when the upper row of windows are open,and 44.4%higher when the lower row of windows are opened than that with all windows open.