附旁路風門可變風量小型室內送風機性能模擬與測試之研究

Performance Rating and Simulation on Air-Conditioning Characteristics of Damper Bypass VAV Fan-Coil Units

朱良堃(Liang-Kun Zhu)

指導教授 ： 柯明村

國立臺北科技大學/機電學院/冷凍空調工程系所/碩士(2006年)

https://doi.org/10.6841/NTUT.2006.00125

摘要

本研究以CFD氣流模擬分析方法解析附旁路風門可變風量送風機系統內流場及溫度場分佈情形，並針對旁路風門不同開度時對流場之氣流分佈、回風混合與出風溫度變化之影響。此外，由於旁路風門的大小與擺設位置將直接影響回風混合均勻與否與出風溫度變化，因此有關VAV送風機旁路風門尺寸大小與擺設位置值得做進一步的深入研究。
在數值模擬包括以三種不同的旁路風門尺寸與不同的擺設位置進行模擬解析，試圖以此方法尋找出旁路風門最佳尺寸大小與擺設位置。由數值模擬結果得知，利用旁路風門特性不僅可增加循環風量及空氣混合度，亦可藉由風門開度控制來提高出風溫度，使VAV送風機出回風溫度差降低之低溫差特性。
當室內負載穩定時，系統將調整風機維持於最低送風量，此最低送風量可使室內空氣之循環率維持在規範的最低限度範圍內，預期可以解決傳統可變風量送風機於低負載時產生傾瀉現象問題，並達到VAV送風機之節約能源及兼顧舒適度之目的。

關鍵字

附旁路風門可變風量送風機(VAV DBFCU) ； 旁路風門 ； 計算流體力學

並列摘要

This study analyzed the distribution of internal flow and temperature fields of the Damper Bypass VAV Fan-Coil Units by computational fluid dynamics technique. The effects of bypass damper opening to the distribution of air flow and returned air mixing as well as changes in air temperature were studied. In addition, because the size of the bypass damper and the placement position directly affect the homogeneity of returned air mixture as well as changes in air temperature, therefore the size and dimension of the bypass damper of the VAV fan-coil unit and its placement position value require further study.
During the simulation analysis, including three different sizes of bypass damper and different placement positions, we tried to look for the best dimension and size and placement position of the bypass damper. According to the simulation results, utilizing the bypass damper not only can increase the amount of circulated air and degree of air mix, but it can also raise the air temperature through the degree of damper opening, so that the VAV fan-coil unit can exhibit low temperature differential characteristic as evidence by the reduced temperature differential of the returned air.
When the indoor cooling load is stable, the system will adjust the fan-coil unit to maintain minimum amount of air flow, this minimum amount of air flow can maintain the indoor air circulation at the lowest standard, and is expected to resolve the dumping phenomenon produced by the traditional variable air volume fan-coil unit at low loading situation, as well as achieving the purpose of energy saving and comfort of the VAV fan-coil unit.

並列關鍵字

Damper Bypass VAV Fan-Coil Units（VAV DBFCU） ； Damper ； CFD

參考文獻

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