基于PIV试验的某核设施厂房气流运动特性研究
Research on airflow movement characteristics of a nuclear facility plant based on PIV tests
摘要：
为研究含有强热源的某核设施厂房室内气流运动特性,建立了其真实全尺寸设备室试验环境舱,基于粒子图像测速(PIV)技术,精确测量了舱内蒸发器区域自然对流工况、机械通风工况的气流运动情况,并对设备室检修工况下的开口区域进行了测速。结果表明:在自然对流工况下,蒸发器热壁面会导致其周围产生特定流场,形成一个温度和流速逐渐升高的上升流,在蒸发器顶部则会形成一个上升的热羽流;在机械通风工况下,蒸发器表面边界层厚度有所减小,蒸发器顶部热羽流受到通风气流的扰动和分散,减少了上升热羽流的集聚,并使其更均匀地分布在设备室房间顶部;在检修工况下,室外气流在压差作用下通过检修开口进入环境舱。当开口流速为1 m/s时,入口速度曲线呈抛物线形状;当检修开口入口流速降低时,速度梯度减小,等速度线不再呈抛物线形状。
Abstract：
To study the characteristics of indoor airflow movement in a nuclear facility plant with strong heat sources, an actual full-scale equipment room test environmental chamber is established, and the airflow movement of the natural convection and mechanical ventilation conditions in the evaporator area of the chamber is accurately measured based on the particle image velocimetry (PIV) technology, and the velocity measurement of the open area under the maintenance condition of the equipment room is carried out. The results show that under natural convection conditions, the hot wall of the evaporator will cause a specific flow field to be generated around it, forming an upwelling with gradually increasing temperature and velocity, and a rising hot plume will be formed at the top of the evaporator. Under the condition of mechanical ventilation, the thickness of the boundary layer on the surface of the evaporator is reduced, and the hot plume at the top of the evaporator is disturbed and dispersed by the ventilation airflow, which reduces the accumulation of the rising hot plume and makes it more evenly distributed on the top of the equipment room. Under the maintenance conditions, the outdoor airflow enters the environmental chamber through the maintenance opening under differential pressures. When the opening flow velocity is 1 m/s, the inlet velocity curve is parabolic. When the flow velocity at the inlet of the access opening decreases, the velocity gradient decreases, and the isovelocity line no longer presents a parabolic curve.
Keywords:strong heat source; nuclear facility; particle image velocimetry (PIV); equipment room; airflow movement; natural convection; mechanical ventilation