低溫差可變風量送風機性能檢測及送風特性研究

Performance Rating and Study on Air-Supplying Characteristics of Low Temperature Differential VAV Fan-Coil Unit

蔡旻錦(Min-Chin Tsai)

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(2005年)

https://doi.org/10.6841/NTUT.2005.00075

摘要

本研究以改善傳統可變風量送風機與低溫送風技術之缺失為考量，設計開發一套創新設備，稱為「低溫差可變風量室內送風機」(Low Temperature Differential Variable Air Volume Fan-Coil Unit, LTD-VAV FCU)，改善上述二項節能技術之運轉缺失，以期兼具空調節約能源與兼顧室內空氣品質之優點。本研究以空調環境模擬實驗室於相關標準環境條件下進行性能檢測，之後以性能檢測結果做為計算流體力學(Computational Fluid Dynamics, CFD)分析之邊界條件，更將實驗歸納之風機特性曲線併入數值模式以進行理論模擬分析，最後將模擬結果套入ASHRAE Standard 55之PMV(Predicted Mean Vote)及PPD(Predicted Percent Dissatisfied)之定義與計算流程，藉以探討本LTD-VAV FCU於負載變動時，對室內氣流及舒適度之影響。
實驗結果指出，經由旁路風門特性，本LTD-VAV FCU之供風量可在0.09 ~ 0.43m3/s間調變，此時空調供應能力在0.39 ~ 5.19kW之間，顯示本設備可依空調負荷之變動，藉由雙重控制的特性自行調變供風量及空調供應能力。此外，在數值模擬分析部份，依假設之室內負載逐時變動曲線，配合本LTD-VAV FCU自行調變出風口邊界條件之運算模式，經由數值模擬結果得知，利用旁路風門特性可增加循環風量及空氣混合率，提高室內舒適度，更可藉其風門開度之控制提高出風溫度，使入出風溫度差降低之低溫差特性，解決因供風溫度過低所造成的空調不舒適感。

關鍵字

低溫差 ； 計算流體力學 ； PMV ； PPD

並列摘要

This study aims to improve the defects of traditional techniques：variable air volume fan-coil unit and coil air distribution. A new innovative technology called Low Temperature Differential Variable Air Volume Fan-Coil Unit, or LTD-VAV FCU, is designed for the improvement, hoping to provide a good indoor environment while keeping the machine as energy effective as possible. The approach of the study is to conduct performance rating in an air-condition simulation laboratory under standard environment conditions. The result of performance rating was then used as the boundary conditions for computational fluid dynamics (CFD) analyses. Furthermore, the LTD-VAV FCU characteristic line, which is deduced from the experiment, was introduced into numerical analysis for air flow simulation analysis. Finally，the results were used in PMV (Predicted Mean Vote, ASHRAE Standard 55) and PPD (Predicted Percent Dissatisfied), to analyze influence of LTD-VAV FCU on indoor air quality and thermal comfort.
The results show that the air supply volume of LTD-VAV FCU ranges between 0.09 ~ 0.43m3/s, owing to the opening of by-pass damper. Presently, cooling capacity is between 0.39 ~ 5.19kW. This shows that the equipment could change its air supply volume and capacity independently according to its cooling load. In addition, regarding numerical analysis, the LTD-VAV FCU was simulated to be capacity and air volume self-adjustable by using experimental date as boundary conditions, and the cooling load was assumed to be varying with time. The results of the numerical analysis show that, the control of by-pass damper can increase circulation air flow rate and mixing rate of air, so as to enhance comfortableness. Furthermore, supply air temperature can be controlled by the adjustment of damper opening, reducing the temperature differential of supply air and room air. Therefore, the low temperature of supply air will no longer cause uncomfortableness.

並列關鍵字

Low Temperature Differential ； CFD ； PMV ； PPD

參考文獻

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