无风墙辅扇通风过程的分析

推导并验证了无风墙辅扇通风的相对有效压力方程及有关特性方程;定义了用于判断是否需设特别混合室的下临界风阻R_d 和需设风墙的上临界风阻 R_u;给出了用风机类型特性方程系数表达的最优辅扇出口断面计算式;指出:无因次特性方程系数 B=0.5 的风机适合于此种方式的通风。现场实验证实,B 接近0.5的 K45系列风机用作无风墙铺扇通风,与用JF型风机相比,能耗降低到一半以下。

Analysis of Ventilation Process Using an Auxiliary Fan without Windbreaks

Derives a relative effective pressure equation and relevant characteristic eq-uations under the ventilation using an auxiliary fan without windbreaks andfurther verifies it. Defines the lower and upper limits of critical air resistancecoefficients, i. e. R_d and R_u, available to make sure whether a special mixingchamber is required (by R_d) or the windbreak required (by R_u), repectively.A formula for optimum cross section of ran offtake is given in terms of thecoefficients of characteristic equation showing various models of fan, and thefans of which the dimensionless coefficient of characteristic equation B=0.5 areproved applicable to such type of ventilation. In-site experimental resultsshow that K45 series fans of which B approaches to 0.5 can save more than 50%of the energy consumed in comparison to Model JF fans under the ventilationwith out windbreaks.