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《制冷与空调(北京)》2017,(1)
风机盘管机组作为集中式空调系统末端在工程中应用非常广泛,目前从市场反馈来看,风机盘管机组电机轴承噪声问题比较突出。本文以某型号风机盘管机组电机轴承为例,通过结构分析、试验验证等,提出一种新的风机盘管机组电机轴承选择方案,该方案能够提高轴承对现场灰尘的防护能力,降低风机盘管机组产生噪声的可能性,提升风机盘管机组可靠性和客户体验。 相似文献
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针对干式风机盘管机组的使用特点,调研行业内关于干式风机盘管机组的研究与发展,结合多年的干式风机盘管产品开发及工程实际使用经验,找出抑制干式风机盘管机组广泛应用的制约因素——换热能力差。并提出一些换热能力优化解决方案:通过优化盘管的管径、翅片的结构,可以增加换热流体在有限空间内的扰流效果;设置合理的翅片间距、盘管排数,以增大换热面积;合理设置换热器的流型,以提高冷热流体间的平均传热温差;调整换热器的流路数,找到最佳的冷冻水管程,适当增加冷热流体的接触时间,进一步优化传热效果。结果表明,通过一系列优化方案的实施,干式风机盘管机组的换热能力整体提升约30%。 相似文献
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本研究采用了基于遗传算法和耗散理论的传热优化方法,并进行了风机盘管换热器的优化设计。在对板翅管式结构的风机盘管换热器进行建模的基础上,针对两种不同的应用工况,即供冷用干式风机盘管换热器和供暖型风机盘管换热器,进行了结构优化设计和分析。优化目标选取了换热器的耗散热阻,而设计变量分别选取管间距、排间距、换热管外径、翅片间距和翅片数。为评价换热器的性能,还计算了换热器的换热量、空气侧和水侧阻力损失、总泵功和换热器效能。优化设计结果显示,在特定的设计参数和限制条件下,不仅换热器的耗散热阻值降低,其他方面性能也得到了明显提升。 相似文献
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李强 《制冷与空调(北京)》2011,(3):94-97
描述我国风机盘管机组噪声问题的现状,分析导致风机盘管机组噪声的3个主要因素,并着重阐述低频噪声的判断方法以及施工规范对预防风机盘管机组噪声的重要性。 相似文献
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Abstract An innovative cooling fan with distinguishing features such as ultra thinness, high performance, and quietness is proposed for notebook computers. In particular, the configuration of the proposed fan allows it to suck the largest volume of hot air from surfaces along the vertical direction and expel exhaust air onto the side surface along the horizontal direction, therefore, thinner notebook PCs can be designed. In order to achieve these characteristics, unique designs are required; a 13‐blade impeller is designed for the centrifugal fan in stead of the common conventional design for axial fans, which is a complicated centrifugal blade shape design. A flat rectangular casing for the fan is designed with external dimensions of 89 mm × 76 mm × 13 mm. The casing contains a rotor impeller and a volute; the design of curved throat of the volute is complicated. The top and bottom surfaces, each, have one circular inlet hole. The side surfaces each have a long rectangular outlet hole. In this study, we focus on the P‐Q performance curves of this centrifugal cooling fan designed for notebook PCs, the P‐Q curves are obtained by numerical analysis and tests based on the AMCA standard 210–85. When this fan is subject to real operating conditions, with regard to the maximum flow rate to the near cut‐off point, the pressure P gradually increases from the fan inlet to the fan outlet. The average percentage (%) error in the flow rate Q was determined by both numerical analysis and AMCA test. Additionally, from the result of the standard CNS‐8753 noise test, the fan noise level is 30~33 dBA and the flow field around the inlet, the outlet and the flow passage can be visualized by Particle Interference Visualization (PIV). Finally, according to the P‐Q curve, it can be inferred that this cooling fan outperforms other comparable regular products available. The noise level is satisfactory, and the heat removal is good; hence this design is proposed for application in industry. 相似文献
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Cheng-Hung Huang Wei-Cheng Tseng 《International Journal of Mechanics and Materials in Design》2016,12(2):223-240
An inverse design problem in determining the optimal shape of volute spiral case for a centrifugal-flow fan is examined in the present study using the Levenberg–Marquardt method and a general purpose commercial code CFD-ACE+, and based on a desired airflow rate. The desired volume airflow rate can be obtained by multiplying the airflow rate of an existing fan by a constant number which is >1. The shape of the redesigned volute case is generated using the equation of the trajectory of fluid particles in the volute, which enables the shape of the fan volute be constructed completely. Finally, prototypes of the original and optimized fan volutes as well as fan impellers are fabricated, thereafter the fan performance is tested based on the AMCA-210-85 standard to verify the validity of the design. The experimental results demonstrate that by utilizing the fabricated centrifugal optimal fan and operating at the design condition, the airflow rate can be increased by 6.5 % and the pressure drop, noise and input power of fan can be reduced by 1.6, 5.3 and 11.4 %, respectively, when compared with the original fan. As a result, the performance of optimal fan can be improved greatly. 相似文献
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对带尾缘吹气的空心叶轮轴流式风机内部流动和气动噪声进行数值模拟计算,并从流动性能和噪声水平2个方面将之与原型风机进行对比分析。结果表明:两者的流动性能差别甚小,但在设计工况附近,空心叶轮风扇的气动噪声明显低于原型风扇。研究结果可为空心叶轮轴流式风机的设计、选型以及结构优化提供依据。 相似文献
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以二元离心风机叶轮叶片型线为研究对象,对7—40和bb24风机叶轮运用等减速和等当量扩张角规律,分别对其进行叶片型线的重新设计,并运用CFD数值模拟叶轮内部复杂三维流动。结果表明,在设计工况下,无论是等减速规律还是等当量扩张角规律对于2个不同的风机叶轮都取得了较好的效果,尤其是应用等减速规律改进的叶轮,改进效果更加明显,叶轮性能显著提高。 相似文献
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如何快速而准确地预测离心风机在所设计的空气处理机组内的性能,对于产品设计人员来说非常必要,但也比较困难。本文介绍一种实用而较为准确地预测离心风机在空气处理机组中性能的方法,从试验方案、依据标准、数据分析和建模方法等几方面进行介绍和讨论。 相似文献
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空调离心叶轮尾流噪声的数值预估 总被引:1,自引:0,他引:1
由于现有的计算技术限制,风机气动噪声的数值预估是非常困难的。对于单个离心叶轮,已知其最主要的气动噪声源是叶片尾缘涡脱落导致的叶片表面压力脉动。基于Lee(1993)的轴流风机尾流噪声模型,提出一种可适用于离心叶轮尾流噪声数值预估方法。它包括三项主要工作:首先利用商用CFD软件Fluent对叶轮内的三维流场进行了数值模拟,并对所得气动性能进行实验验证;然后对叶片尾缘附近的速度剖面进行分析,提取出吸力面和压力面两侧的边界层厚度;最后,根据改进的噪声预估模型对叶轮的总声压级进行数值预估,在设计工况附近所得结果与实验值相比误差小于3dB。 相似文献