洗衣机烘干用离心风机气动特性及加热管传热特性研究

发布时间：2018-02-11 05:11

本文关键词： 离心风机气动性能降噪加热管换热性能　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：为克服狭长复杂风道的阻力,洗烘一体机的烘干系统采用大压头的离心风机进行气流驱动;为增强传热效果,采用高功率的加热管束进行加热。但逼仄狭小的烘干风道极大制约了离心风机的气动性能,加之风道轮廓的不合理,大大增强了离心风机的气动噪声;而光滑的加热管束虽然产生的流动阻力较小,但同样造成加热管传热性能的削弱。为了合理匹配离心风机的流场和加热管的传热特性,增强风机气动性能,降低风机气动噪声,提高加热管传热性能,本文以滚筒洗衣机的烘干系统为研究对象,对离心风机的流场及噪声特性和加热管束的传热特性进行了相关研究。首先,采用数值模拟方法,通过FLUENT软件对滚筒洗衣机烘干风道内离心风机的运行工况进行模拟,获取了风机的流场信息;其次,通过分析风机流场信息得知制约风机气动性能的因素是蜗壳、蜗舌及流道轮廓,分别对其进行优化设计,并结合气动噪声理论对噪声进行研究;之后,针对气动性能和气动噪声的研究结果,提出风机和流道的综合设计,发现改进模型相比原型风机全压提升23.05%,效率提升20.11%,总噪声值下降了3.61 dB(A);最后,采用数值模拟方法研究了改进模型下加热管束的直径、行距列距、排布方式、截面形状和表面形状对其传热特性的影响,发现在产生较小流动阻力的前提下,仅在改变加热管的截面形状和表面形状时,其传热性能相对原型得以提高。另外,为证明改进模型的风机气动性能和气动噪声相对原型具有较优的设计效果,制作原型和改进模型的烘干风道,并配合离心风机进行装配。分别测试二者全工况下的风机性能曲线,发现改进模型下的离心风机的全压及效率曲线远远优于原型。分别将原型和改进模型装配到滚筒洗衣机烘干系统内,并在半消声室内进行洗衣机烘干工况的气动噪声测试,发现改进模型的整机噪声相对原型降低了2.54 dB(A)。实验结果证明了数值模拟方法的可靠准确。
[Abstract]:In order to overcome the drag of narrow and complicated air duct, the drying system of the integrated washing and drying machine is driven by centrifugal blower with large pressure head, in order to enhance the effect of heat transfer, The high power heating tube bundle is used to heat the centrifugal fan, but the narrow and narrow drying air duct greatly restricts the aerodynamic performance of the centrifugal fan, and the air duct profile is unreasonable, which greatly enhances the aerodynamic noise of the centrifugal fan. The smooth heating tube bundle, although the flow resistance is small, also results in the weakening of the heat transfer performance of the heating pipe. In order to reasonably match the flow field of the centrifugal fan and the heat transfer characteristics of the heating pipe, enhance the aerodynamic performance of the fan and reduce the aerodynamic noise of the fan, In order to improve the heat transfer performance of heating pipe, the flow field and noise characteristics of centrifugal fan and the heat transfer characteristic of heating tube bundle are studied in this paper, taking the drying system of drum washing machine as the research object. Firstly, the numerical simulation method is used. The flow field information of the fan is obtained by simulating the operating condition of the centrifugal fan in the dryer duct of the drum washing machine by using FLUENT software. Secondly, through analyzing the flow field information of the fan, the author finds out that the factor restricting the fan's aerodynamic performance is the volute. The contour of cochlear tongue and channel are optimized, and the noise is studied in combination with the theory of pneumatic noise. Then, according to the research results of aerodynamic performance and aerodynamic noise, the comprehensive design of fan and channel is put forward. It is found that compared with the prototype fan, the improved model is 23.05, the efficiency is increased 20.11, the total noise value is reduced by 3.61 dB / An. Finally, the diameter, row spacing and arrangement of the heating tube bundles under the improved model are studied by numerical simulation. The influence of cross section shape and surface shape on heat transfer characteristics shows that the heat transfer performance of the heating tube can be improved by changing the cross section shape and surface shape of the heating tube only when the flow resistance is small. In order to prove that the aerodynamic performance and aerodynamic noise of the improved model have better design effect than the prototype, the prototype is made and the drying duct of the improved model is made. And combined with centrifugal fan assembly. Test the fan performance curves under both conditions, It is found that the full pressure and efficiency curve of centrifugal fan under the improved model is much better than the prototype. The prototype and the improved model are respectively assembled into the drum washing machine drying system, and the aerodynamic noise of the washing machine drying condition is tested in the semi-anechoic chamber. It is found that the whole machine noise of the improved model can be reduced by 2.54 dBU / AU relative to the prototype. The experimental results show that the numerical simulation method is reliable and accurate.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM925.33

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