氣冷式冰水機冷凝盤管與元件配置最佳化之氣流模擬分析

CFD Simulation for Optimum Coil and Component Configuration on Air-Cooled Chiller

李孟延(Meng-Yeng Lee)

指導教授 ： 李宗興

國立臺北科技大學/機電學院/冷凍空調工程系所/碩士(2005年)

摘要

大型氣冷式冰水機之冷凝器通常係由多組鰭管式冷凝盤管所組成，由於受到機組外型尺寸之限制，使得冷凝盤管組之配置以及機組較大型元件之擺放位置常有許多種不同之設計考量。然而，盤管與大型元件之配置會影響經過冷凝盤管之氣流分佈，造成盤管表面風速不均勻，進而影響冷凝盤管散熱效率以及機組能源效率。因此尋找最佳之冷凝盤管配置與底部元件擺設方式的組合，藉以改善氣流分佈與提高熱傳性能之相關研究，就成為此類設備性能提升之重要課題。
有鑑於此，本研究主要的目的在於：利用CFD氣流模擬與熱交換器熱傳分析，再配合大型氣冷式冰水機組之實驗驗證的方法，考量在相同機組外型尺寸與風機性能之限制條件下，進行不同盤管配置搭配底部元件擺設位置共九個設計案例之氣流模擬與熱傳分析，藉由探討各個案例冷凝盤管的氣流分佈與熱傳性能之差異，尋找最佳之冷凝盤管及底部元件配置方式。
研究結果發現：在無底部元件設置之情況下，盤管配置以案例3為最佳。若以案例1為基準，則盤管總平均風速改善率可達9.5%，熱傳量可改善6.2%；當底部元件設置為A型式時，則以案例2A之盤管配置為最佳，盤管總平均風速改善約11.0%，而熱傳量改善則約7.2%；若以底部元件B方式擺設時，則案例2B為最佳，總平均風速改善約10.1%，總熱傳量改善約6.6%。九個案例中以2A為最佳之設計。

關鍵字

氣冷式冰水機 ； 鰭管式熱交換器 ； 計算流體力學

並列摘要

The main purpose of this study is to find out the optimum coil configuration and the component layout. Air-cooled liquid chiller coil configuration and components layout could strongly affect the condensing coil heat transfer. The coil configuration could affect the face velocity of condensing coil, while the component layout could affect the uniform of face velocity. CFD software-Airpak 2.1 is employed to simulate air flow field of the coils and components configuration. The numerical result was used to calculate the heat transfer of each coil. Compare with the baseline case 1. Without the components, case 3 could raise the average velocity nearly 9.5% and the heat transfer about 6.2%. Components layout A type, case 2A could raise the average velocity 11% and the heat transfer 7.2%. The optimum case of component layout B type is case 2B, the average velocity could raise 10.1%, and heat transfer could raise 6.6%. The optimum case of all cases is the case 2A.

並列關鍵字

Air-cooled liquid chiller ； finned-tubes heat exchanger ； CFD

參考文獻

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