传统换气次数测量方法的问题及其改进
Problems in conventional measuring method of air changes and its improvement
摘要：
以示踪气体下降法为例，通过实测和模拟分析，指出传统示踪气体测量换气次数方法存在的问题：因依据均匀混合理论，以拟合浓度曲线斜率的方法得到的各点换气次数基本相同，不能很好地反映各点的换气能力差异；同时，求取房间平均换气次数的方法存在数学原理上的不足。建议采用反映局部换气能力的指标——局部换气次数，并给出获得新的换气次数的方法。
Abstract：
By means of field measurement and numerical simulation analyses, taking a tracer gas dropping technique as an example, points out the problems existing in conventional measuring method with tracer gases that the differences among different points cannot be reflected correctly as the measured air changes of different points are almost the same when using the fitting curve slope of concentration according to the uniform mixture theory. Meanwhile, in the method of solving the average room air changes exists some deficiency in mathematical fundaments. Proposes adopting the index reflecting local air change ability—air changes of local area. Gives a procedure for solving the new index.
Keywords:ventilation, air changes, measuring method, air age, tracer gas