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臺灣能源期刊論文全文

臺灣能源期刊第3卷第2期內容

出刊日期:June, 2016

題目
太陽能集熱板碳黑吸收膜之最佳化噴塗製程參數研究
Title
Parametric Study on Spray Coating Process for Selective Absorbing Film of Solar Collector
作者
劉名育、謝宗旻、張克勤、劉怡眉
Authors
Ming-Yu Liu, Tsung-Min Hsieh, Keh-Chin Chang, Yi-Mei Liu
摘要
太陽能熱水系統為迄今太陽熱能之最普及應用,文獻指出集熱板集熱效率影響最具關鍵的有吸收膜厚度的控制、表面分布均勻性,以及材料性質和其顆粒大小。本研究利用雙流體自動噴槍以及碳黑材料吸收膜噴覆至試片,選定四個控制因子包括噴槍氣液壓組合、噴塗高度、碳黑材料濃度與噴槍速率,採用田口方法得到此製程的最佳化參數組合。以L9 (34)實驗直交表減少實驗的次數得到足夠的統計資料,同時量測試片的吸收率、吸收率及放射率比值與膜厚等性能資訊,進行變異分析以探討各因子的影響力。經變異分析後,根據需求選定最佳化控制因子及水準組合分別為氣液壓組合2.0/0.6 kgf/cm2、噴塗高度28 cm、漆與香蕉水比例1:2與噴槍速率29.57 cm/sec。經確認實驗後與原始設定製程比較,吸收率及放射率比值從1.384減少至1.379,S/N比從24.76 dB提升至26.02 dB;吸收率從0.910提升至0.914,S/N比從27.76 dB提升至28.89 dB。結果顯示雖然品質特性無明顯變化,但均勻度有些微提升。最後由日曬實驗量測試片之最終平衡溫度,最佳化製程達到了97.3oC相對於原始製程之95.6oC,驗證了田口式直交表實驗最佳控制因子及水準組合的結果。
關鍵字
噴塗製程、碳黑吸收膜、太陽熱能、田口方法
Abatract
Solar water heaters have been the most popular application of solar energy. The Thickness Sensitive Spectrally Selective (TSSS) characteristic of the absorbing film plays a key role in determining the thermal collection efficiency of solar collector. The key factors to determine the TSSS characteristic include the thickness, uniformity, and material with its powder size of the absorbing film. A parametric study in terms of (1) pressure of gas/liquid, (2) injection height, (3) concentration ratio of paint to solvent, and (4) moving speed of nozzle is performed with Taguchi method. Quality of TSSS characteristic is monitored by the absorptivity and emissivity of absorbing film. The performance of the spray coating process is justified using the absorptivity and emissivity of the TSSS characteristic in this study. The optimal combination of L9(36) orthogonal array is as follows: gas/liquid pressure of 2.0/0.6 kgf/cm2, 28 cm for height, 0.5 for the ratio of concentrations between paint and solvent, and 29.57 cm/s for moving speed of nozzle. It turns out that the quality characteristic for α⁄ε is slightly decreased from 1.384 to 1.379, and the S/N ratio of absorptivity is increased from 27.76 dB to 28.89 dB, as comparing between the confirmation and original tests. From the measured equilibrium temperatures which were obtained from the sunshine field experiments, the temperature of the optimal process can reach 97.3oC as comparing to 95.6oC of the original process. It validates the result of the factor combination for optimal process made from Taguchi’s orthogonal arrays.
Keywords
Spray coating, spectrally selective absorbing film, solar thermal energy, Taguchi method