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As ventilators are very extensively applied in various industries, centrifugal fan has a certain demand in the market. In addition, in recent years people have greater environmental awareness and support energy saving and carbon conservation, urging many fan manufacturers to look for ways to produce high performance and high efficiency fans, which shall become a trend in the industry in future. Attempting to replace the traditional plate blades by airfoil blades, the study uses CFD software and experimental design technique to look for parameters of high efficiency centrifugal fan. First of all, the paper uses full factorial experiment to analyze the parameters like installation angle, exit angle and chord length of NACA 8411 blade. The study finds that the airflow along geometric shape of airfoils is smoother than traditional plate blades. It is clearly shown from the increased total pressure efficiency, which rises from 75.2% of traditional plate blades to 78%, with an increase rate of total pressure efficiency at around 3%. Therefore, it is firmly believed that fans with airfoil blades tend to have high efficiency. Since there is a number of airfoil cross-section models in NACA series, the paper finds the vertical coordinate scale value, horizontal coordinate scale value and maximum thickness of NACA airfoil cross-section to conduct factorial experimental analysis of orthogonal array, and then makes slight adjustment to the key components of inlet cone and cover board of fan. As known from simulation results of airfoil centrifugal fan, the optimal rate of chord length of blade to outer diameter of wind turbine is 0.318, and the optimal ratio of maximum thickness to chord length of airfoil blade is 1:12.5. The study discovers that NACA 6508 airfoil blade have an optimal total pressure efficiency of model at 82.19%, with overall efficiency tremendously raised by 9.3%. After improvement, a fan can save around 4,900 degrees of electricity (electricity charge NT$14,000) and decrease carbon dioxide emission volume by 3.14 tons, achieving the goals of energy saving and carbon reduction. The study additionally assists a domestic famous fan manufacturer to improve the manufacturing process of the key component of wheels for centrifugal fan by selecting effort-saving way for manufacturing process of wheels. This process is divided into four workstations, and mainly offers improvement to workstation 1 (spot welding station) and workstation 3 (cooling station). After the wind turbine manufacturing process has been improved, the daily production volume of wind turbine increases from 2 to 4, production capacity increases by 1 time, and efficiency increases by 1.4 times, letting the process achieve the greatest economic benefit and high-efficiency output.
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