雙吸入後傾式離心風機數值與實驗整合研究

An Integrated Numerical and Experimental Study of Double-Suction Backward-Curved Centrifugal Fan

黃朝瑋(Zhao-Wei Huang)

指導教授 ： 黃博全

國立臺北科技大學/機電學院/冷凍空調工程系所/碩士(2006年)

摘要

由於節約能源與降低噪音的環保壓力逐漸提升，及國外風機製造業的競爭，促使國內風機業者單靠以往模仿的生產方式已無法應付時代之變化，唯有尋求發展高性能低噪音的風機，才是未來的趨勢。本計畫是因應風機製造商之要求，協助改善其目前工業級翼型後傾式離心風機之產品性能而誕生。
本研究之目的即針對工業級後傾式雙吸入翼型離心風機發展一套結合電腦輔助流場特性分析與實驗測試之整合研究方法，以協助風機業者提昇設計分析能力，並生產出高效能、低噪音之風機。
研究所採用方法是首先依據廠商所提供一型離心式風機的造型，建立起該風機之電腦3D曲面之實體圖，再利用計算流體力學數值CFD商用套裝軟體，模擬並分析氣流通過風機時內部流場特性與預測之性能曲線，接著以實作方式製作前述之風機雛型後，以實驗方法量測其性能，經比對預測值與實驗量測結果作修正，確認所建立之風機性能數值模式準確可被接受後，再並進一步利用已修正CFD的離心風機分析模式，研究提升風機效率之可能方法(如入口錐造型、葉輪寬度、葉片角度及中心體等)，找出理想的修正形狀條件後，即可協助合作廠商改善風機性能，提昇其效率。
研究結果發現將葉片安裝角由38度提高到42度，出口全壓增加10.5%，風機性能大幅提升；而加裝中心體於中蓋板的效果對於性能的改善只有些許，僅出口全壓增加2.26%，但高10cm中心體使空氣進入轉輪較為平順；當縮短葉輪高度時則會使性能下降，如葉輪高度縮短為原來的0.75倍，則平均出口全壓減少6.92%。

關鍵字

後傾式翼型離心風機 ； 計算流體力學 ； 葉輪 ； 入口錐 ； 流場分析

並列摘要

Due to the gradual increasing environment-protective pressure in energy saving and noise reducing as well as the technology challenge coming from foreign manufacturer, the domestic producers who make copying fan feel that they can not adapt the change of era except for developing the high-performance and low-noise fan for the future. This research program is developed for improving the performance of industrial airfoil centrifugal fan.
The purpose of this study is to develop an integrating research capacity for backward-inclined double-inlet airfoil centrifugal fan, which combines the computer-aided flowfield analysis and experimental measurement, to promote the ability in fan-design analysis for fan builder and to produce high-effective turbo centrifugal fan.
The research method in this project is (1) to create three-dimensional solid graph of centrifugal fan provided by cooperative manufacture, (2) to use the CFD business package software to simulate the airflow passing through the fan system, and to draw the predicted performance curve of fan, and (3) to build the fan system model and experimentally investigate the performance of this fan prototype. The differences between both predicted and experimental results are modified, until the new numerical results are accepted accurately. Further, to apply the new CFD numerical scheme to explore the possible factors (such as changing blade angle, impeller width, and central body etc.), which can promote the performance efficiency of fan. After finding an ideal cone or volute shape, the efficiency of origin fan system can be improved.
The results show that (1) as the blade angle increases from 36° to 42°, the outlet total pressure increases up to 10.5%, which significantly improves the performance efficiency of fan, (2) adding center body on centric hub plate makes the inlet air flow enter into the impeller more smoothly, which promotes slightly performance efficiency of fan about 1.01% for the center body 10cm height, with(3) reducing the width of impeller reduces the fan performance. The average total pressure lessens 2.26% for a fan with 0.75 fold height of original impeller.

並列關鍵字

The backward-inclined airfoil centrifugal Fan ； Computational fluid dynamics ； Impeller ； Inlet cone ； Flowfield analysis

參考文獻

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