分離式空調室內與室外機氣流模擬分析

Airflow Simulation of Indoor and Outdoor Units for the Split-Type Air Conditioner

陳俊維(Jun-Wei Chen)

指導教授 ： 施陽正

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.2006.00397

摘要

分離式空調機因其安裝美觀、低噪音、安裝不受限制及設備費用愈來愈低廉等優點，使分離式空調機已成為目前小型空調機市場的主流，為了改善其性能與噪音，本研究利用計算流體力學軟體FLUENT V. 6.1進行氣流模擬分析。在室內機部份，本研究著重於改變背板間距與舌部延伸風道結構兩個參數，對其性能與噪音的影響；經由模擬結果中比較橫流扇內部流場的變化並探討其對性能的影響，以及藉由模擬出的聲壓位準值分析其產生的氣動噪音。模擬結果顯示當背板與轉子距離為5.5mm 所產生的最大葉片頻率單音值較小，並發現改變舌部延伸風道上結構對於送風性能與噪音的降低並無太大的幫助。在室外機部份，本研究著重於改變螺旋扇位置與喇叭口形式對其出風口風量的影響，模擬結果顯示，適當的風扇位置可以得到最佳的送風量，而改變喇叭口形式對送風量的影響甚小。此外本研究亦針對室外機的安裝位置對於空調機的性能影響進行分析，比對文獻上的實驗數據與本研究的模擬結果，顯示溫度場的最大相對誤差值在6％內；所以本研究結果顯示利用計算流體力學方法研究室外機最佳安裝位置是非常可靠的，並且是有效以及可節省花費的最佳工具。

關鍵字

分離式空調 ； 橫流扇 ； 計算流體力 ； 葉片通過頻率

並列摘要

Because of the advantage of good outlook, low noise, compact size and reasonable price, the split-type air-conditioner has become the mainstream in the market of small-sized air-conditioners. In order to improve the performance and reduce the noise of the split-type air-conditioner, this study adopts the CFD software FLUENT V. 6.1 to perform the airflow simulation for both indoor and outdoor units. The analysis of the indoor unit focuses on the impact of the clearance of the rear wall and the structure of the extended wall of the tongue on the fan performance and noise generation. The simulation results reveal that the gap between the rear wall and the rotor is equal to 5.5 mm, resulting in the lowest value of blade frequency tone. However, changing the structure on the extended wall of the tongue is not helpful to improve fan performance and reduce noise. In the simulation of the outdoor unit, the effects of the position of propeller fan and the structure of bell MOUTH on the volume flow rate are our main concerns. According to the CFD simulation, it is known that suitable position of propeller fan can generate the largest volume flow rate and the structure of bell MOUTH has very tiny influence on the volume flow rate. Moreover, to investigate the installed position of the outdoor unit on the performance of the air-conditioner, velocity and temperature fields around the outdoor unit placing at different location are simulated in this study. To compare the simulation results with the experimental data available in the literature, it is found that the largest relative error between both results is less than 6%. Therefore, the results show that using the CFD method to study the optimal installed position of the outdoor unit is reliable. Also, it is a very cost-effective tool.

並列關鍵字

split-type air-conditioner ； cross flow fan ； Computational Fluid Dynamics ； Blade Passing Frequency (BPF)

參考文獻

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