PET射吹拉成型加熱箱層流與紊流之流場分析

PET Stretch Blow Molding Heating Box Shot Laminar And Turbulent Flow Field Analysis

張芳寧(Fang-Ning Chang)

指導教授 ： 謝宜宸

國立虎尾科技大學/工程學院/機械與機電工程研究所/碩士(2014年)

https://doi.org/10.6827/NFU.2014.00028

摘要

PET射吹拉成型加熱箱其生產過程是瓶胚使用機器懸掛並以一定速旋轉前進經過PET射吹拉成型加熱箱內，透過紅外線燈管加熱以及鋁板反射使其更節省熱能之能源，瓶胚定速旋轉則是讓瓶胚能更均勻受熱，PET射吹拉成型加熱箱下方與左右兩側各安置一台鼓風機，使PET射吹拉成型加熱箱之瓶胚內外側溫度差不會過大，進而生產出厚度更平均更接近理想之產品。

本研究主要使以COMSOL算分析軟體配合標準k–ε紊流模式與層流模式建立幾何模擬PET射吹拉成型加熱箱的三維流場模型，藉由改變不同風速大小與風速方向來探討PET射吹拉成型加熱箱流場在九個瓶胚周圍之流場分佈情形、流量大小之變化以及在標準k–ε紊流模式與層流模式中的差異性。期望可以提供足夠的資訊做為PET加熱箱逐步改良設計或是改善瓶胚厚度不均勻情況的依據。

由流速流線圖之研究結果顯示，PET射吹拉成型加熱箱內流場分佈均勻，風速越大其平均流速流線之數值則越大。兩種模式之誤差值最大處普遍發生在瓶胚上半部靠近邊界出口處，流量方面發現PET射吹拉成型加熱箱內部之流量有對稱之情況產生，散熱影響方面則是以case3搭配風速大小0.5m/s時，流量曲線圖趨勢較均勻且九個瓶胚半徑外圍2mm之所有切面流量較其他case大，故有較佳之散熱情況。

關鍵字

流場分析 ； 模擬 ； PET ； 成型 ； 有限元素

並列摘要

PET stretch blow molding radiation heating box Preform its production processis the use of the machine and to a certain speed of rotation hanging forward through PET stretch blow molding heated inside shot to make it more energy-efficient heat through infrared lamp heating and aluminum reflector, Preform constant speed of rotation is to allow more uniform heating Preform, PET stretch blow molding shot below the left and right sides of each placement of a heating box fan, so PET stretch blow molding shot outside the box of the preform heating temperature difference is not too high thus producing a more even closer to the ideal thickness of the product.

This research makes to COMSOL count analysis software with standard k-ε turbulence model and the laminar flow pattern established geometric analog PET stretch blow molding heated tank shot a three-dimensional flow model, by changing the size of the different wind direction and wind speed to explore PET shoot stretch blow molding heated tank flow field in nine Preform flow field around the distribution, as well as changes in traffic volume in the standard k-ε turbulence model and the laminar flow pattern in the differences. Expected to provide sufficient information as PET heating tank gradually improved design or improve the situation of uneven thickness Preform basis.

The results from the study of the flow rate of the flow chart display, PET stretch blow molding heated shot inside the flow field distribution, the greater the value of the average velocity of the flow rate of the connection is. The maximum error of the widespread occurrence of the two modes on Preform half near the border exit traffic areas found shot PET stretch blow molding inside the heating tank flows have symmetrical situation arising, the heat impact with the wind speed is based case3 0.5m / s, the flow graph of the trend is uniform and nine peripheral preform radius of 2mm all facets traffic than any other case large, so there's a better heat dissipation.

並列關鍵字

flow field analysis ； simulation ； PET ； forming

參考文獻

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