【作者】 吕萌萌；

【导师】 朱能；

【作者基本信息】 天津大学 ， 供热、供燃气、通风与空调工程， 2009， 硕士

【摘要】 射流诱导风机作为实现射流诱导通风方式的主要产品之一,在地下车库等通风系统中得到广泛的应用。射流诱导风机的喷口部分是实现这种通风方式的重要关键技术之一。本文选取同轴射流风口为主要研究对象,通过正交试验对同轴射流风口的射流特性进行研究,将同轴射流方式应用到射流诱导风机的喷口上,以期为射流诱导风机提供新的喷口形式。本文建立了同轴射流风口试验平台,依据正交试验理论,选择9种代表性的同轴型风口,对其风量、压力损失、最大中心速度、射程、扩散宽度、上升距、下降距进行测量,得到了9种风口的射流特性,并对试验误差进行了定性分析。采用正交试验分析方法中的单指标直观分析法,对射程、扩散角、压力损失及卷吸比指标进行分析,评价其影响因子的权重并确定最优水平。采用综合评分法对同轴射流风口的应用范围进行分析。针对于喷口的不同性能,其影响参数的重要程度各异,所选取的最优水平也各不相同。当喷口应用于不同条件下时,可以根据需求的不同,采用不同的结构形式,以期获得所需的射流特性。通过对实验数据的分析,得出直筒型同轴射流喷口的射流流型与圆形喷口的流型相似,射程与圆喷口射程基本相近,但具有较好的掺混及诱导特性。同轴射流的射流特性仅与其结构特征有关。当以射程及卷吸比为指标时,对喷口性能影响权重最大的是供给压力;当以扩散角为指标时,内外圆筒的面积比成为主要影响因素,并对增大射流扩散角有较显著的作用;当以压力损失作为指标时,不适宜的压力范围会产生较大的压力损失。本文将同轴射流喷口引入低速射流诱导通风系统中,与诱导风机相结合,通过正交试验分析,得到了同轴射流喷口的性能,为射流诱导风机风口形式提供了新的选择,丰富了射流诱导风机产品,并对其实际应用和选型提出指导意见。更多还原

【Abstract】 As an important component of the ductless inductive ventilation system, the jet inducted fan is used more and more widely in ventilation system of underground garage. And the nozzle of the jet inducted fan is an important part of the ventilation system. The paper chooses the nozzle of coaxial jet as the main research subject to study the jets’fluid flow characteristics by the means of orthogonal design. And the nozzle of coaxial jet will be used on the jet inducted fan to provide the fan with a new type of nozzle.The experiment establishes a test platform based on the orthogonal design theory and tests for the jets’fluid flow characteristics of nine kind of typical coaxial nozzle. Tests include the air flow, pressure loss, the largest center speed, throw, diffusion width, upper and lower boundary. Then the paper analyses the qualitative analysis of errors.This paper studys the jets’fluid flow characteristics with the throw, the spread of angle, pressure loss and the ratio of inducement, analyses the main effect parameters of nozzle and concludes the optimal level of the parameters. The paper concludes the range of application of the nozzle according to the scientific method of scoring. According to a variety of characteristics, the effect parameters of nozzle are different and the optimal level of the parameters are variational. It should be based on the different conditions to choose the nozzle for the optimal effect.According to the analysis, the flow pattern of coaxial jet is similar to round jet. Although the throw is also similar, the coaxial jet has a better mixing characteristics. Flow characteristics of coaxial jet are only the relevant features of its structure. The main influencing factor is pressure when using the throw and the ratio of inducement as the performance index. The ratio of the area is an important factor of the spread of angle. The unsuitable pressure will bring the more pressure loss.The paper studys the characteristics of coaxial jet in the ventilation system, provides a new flow characteristics to the jet inducted fan by the means of orthogonal design and gives some guidances for the application of the nozzle.更多还原