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A prediction method of operation trend for large axial-flow fan based on vibration-electric information fusion 被引量:4
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作者 GU Zhen-yu ZHU Yao-yao +1 位作者 XIANG Ji-lei ZENG Yuan 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第6期1786-1796,共11页
As the critical equipment,large axial-flow fan(LAF)is used widely in highway tunnels for ventilating.Note that any malfunction of LAF can cause severe consequences for traffic.Specifically,fault deterioration is suppr... As the critical equipment,large axial-flow fan(LAF)is used widely in highway tunnels for ventilating.Note that any malfunction of LAF can cause severe consequences for traffic.Specifically,fault deterioration is suppressed tremendously when an abnormal state is detected in the stage of early fault.Thus,the monitoring of the early fault characteristics is very difficult because of the low signal amplitude and system disturbance(or noise).In order to overcome this problem,a novel early fault judgment method to predict the operation trend is proposed in this paper.The vibration-electric information fusion,the support vector machine(SVM)with particle swarm optimization(PSO),and the cross-validation(CV)for predicting LAF operation states are proposed and discussed.Finally,the results of the experimental study verify that the performance of the proposed method is superior to that of the contrast models. 展开更多
关键词 large axial-flow fan early fault state prediction particle swarm optimization
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Multi-point airfoil optimization for axial-flow fan
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作者 DUAN Haojie LIU Lei DAI Ren 《排灌机械工程学报》 EI CSCD 北大核心 2019年第6期469-474,共6页
Airfoil is the element of fan blade design. It is strongly anticipated to design a fan of ave- raged high performance over a wide operation range. Multi-point optimization design of airfoil for axial flow fan was prop... Airfoil is the element of fan blade design. It is strongly anticipated to design a fan of ave- raged high performance over a wide operation range. Multi-point optimization design of airfoil for axial flow fan was proposed over specific operation range. Weighted objective function of airfoil lift-drag ratio was constructed for several operation points around the designing one. Airfoil was defined by parametric B-spline curve of limited shape controlling points. Results show that normal standard airfoils have remained spaces to be optimized under specific operation conditions. Airfoil performance is sensitive to flow′s Reynolds number and cascade solidity. Predicting flow transition along airfoil profile is essential to search for optimized one. Optimized airfoil of wide operation range is possible to obtain with prescribed fitness function. Obtainments of multi-point optimization may be relatively lower at design point, but positive obtainments are achieved at off-design ones. Resulted airfoil is specially suitable for axial flow fans operating frequently at off-design point such as air condition coolers. 展开更多
关键词 multi-point optimization GEOMETRY DESCRIPTION lift-drag RATIO operation range axial-flow fan
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Thermo-flow characteristics and air flow field leading of the air-cooled condenser cell in a power plant 被引量:8
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作者 ZHANG WanXi YANG LiJun +1 位作者 DU XiaoZe YANG YongPing 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第9期2475-2482,共8页
Special A-frame geometry of the air-cooled condenser cell and the complicated flow field at the exit of the axial flow fan bring on the air mal-distribution on the surface of the finned tube bundles and the deteriorat... Special A-frame geometry of the air-cooled condenser cell and the complicated flow field at the exit of the axial flow fan bring on the air mal-distribution on the surface of the finned tube bundles and the deteriorated thermo-flow performances of a condenser cell. It is of benefit to the design and operation optimization of the direct dry cooling system in a power plant to investigate the thermo-flow characteristics of the condenser cell and propose the flow leading measures of cooling air. On the basis of the representative configuration of the air-cooled condenser cell in a 600 MW direct dry cooling power plant, the computa- tional models of the air side fluid and heat flows are built, in which the actual fan blade geometric details are considered. Various flow field leading ways of cooling air are presented and the thermo-flow characteristics in the A-frame condenser cell and through the finned tube bundles are compared. Results show that the flow field leading measures can result in the increased volumetric flow rate and heat rejection, thus bringing on the improved performance of the condenser cell. The improvement of thermo-flow oerformances depends upon the geometric details of the flow guiding device. 展开更多
关键词 air-cooled condenser axial flow fan t'mned tube bundle flow and heat transfer characteristics flow field leading
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Analysis of Tonal Noise Generating Mechanisms in Low-Speed Axial-Flow Fans 被引量:2
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作者 Edward Canepa Andrea Cattanei Fabio Mazzocut Zecchin 《Journal of Thermal Science》 SCIE EI CAS CSCD 2016年第4期302-311,共10页
The present paper reports a comparison of experimental SPL spectral data related to the tonal noise generated by axial-flow fans.A nine blade rotor has been operated at free discharge conditions and in four geometrica... The present paper reports a comparison of experimental SPL spectral data related to the tonal noise generated by axial-flow fans.A nine blade rotor has been operated at free discharge conditions and in four geometrical configurations in which different kinds of tonal noise generating mechanisms are present:large-scale inlet turbulent structures,tip-gap flow,turbulent wakes,and rotor-stator interaction.The measurements have been taken in a hemi-anechoic chamber at constant rotational speed and,in order to vary the acoustic source strength,during low angular acceleration,linear speed ramps.In order to avoid erroneous quantitative evaluations if the acoustic propagation effects are not considered,the acoustic response functions of the different test configurations have been computed by means of the spectral decomposition method.Then,the properties of the tonal noise generating mechanisms have been studied.To this aim,the constant-Strouhal number SPL,obtained by means of measurements taken during the speed ramps,have been compared with the propagation function.Finally,the analysis of the phase of the acoustic pressure has allowed to distinguish between random and deterministic tonal noise generating mechanisms and to collect information about the presence of important propagation effects. 展开更多
关键词 axial-flow fans Tonal noise Acoustic response
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Visualization and Experiment of Tip Vortex Phenomenon in Cooling Fan using Digital Particle Image Velocimetry 被引量:1
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作者 Junlong Xie Xuejun Wang +1 位作者 Guanghui Wu Keqi Wu 《Journal of Thermal Science》 SCIE EI CAS CSCD 2004年第4期321-327,共7页
The Digital Particle Image Velocimetry (DPIV) is an efficient method for measuring the internal flow field of a low-speed cooling fan. This paper studied the velocity field by means of PIV technology for a leading edg... The Digital Particle Image Velocimetry (DPIV) is an efficient method for measuring the internal flow field of a low-speed cooling fan. This paper studied the velocity field by means of PIV technology for a leading edge swept axial-flow fan without casing, and the tip vortex phenomenon was observed. Time-averaged velocity measurements were taken near the pressure surface, the suction surface and the tip of blade, etc. Moreover, the flow characteristics were visualized using numerical techniques. Experimental results showed that this tip vortex existed at the leading edge of the blade. The generating, developing and dissipating evolvement process of the tip vortex from the blade leading edge to downstream were discussed in detail. In addition, by comparing DPIV results and numerical results, a good agreement between them indicated a possibility to predict flow field using CFD tools. The experimental data provided in this paper are reliable for improving the aerodynamic characteristics of the open axial fan. 展开更多
关键词 flow VISUALIZATION open axial-flow fan DIGITAL particle image VELOCIMETRY TIP vortex.
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