- 學位論文
大型區域空調氣流精細控制之實驗與數值模擬研究
Field Testing and Numerical Simulation for The Precise Thermal Control of Large Laboratory
摘要
本研究主要針對某國家研究中心的實驗區域進行空調氣流模擬分析，藉由實地量測空調系統作為計算流體力學(computational fluid dynamics, CFD)邊界條件的依據，模擬最合適該中心現況之送/回風口條件與配置，預測其效益性作為空調工程上的輔助與驗證。空調系統的優劣取決於風口與裝設位置，許多研究顯示等溫噴流時空氣之射距與送風口之平均面速度有關，噴流行經之距離則與送風速度、風量、送風口面積和速度分佈形狀有關連，因此、對於空調空間的評估首重於送風口的各項參數。 本文研究目的為確保精密儀器設備可在恆溫恆濕之空調環境下正常操作而且能減少量測誤差，探討如何使大型空間內之環境溫度穩定度控制於最小之溫度波動範圍內。透過數值模擬分析與空調設計概念，嘗試提出符合實際現場要求之空調改善方式。研究顯示利用低溫差送風、適當的送回風位置以及高空氣置換率快速帶走室內顯熱負荷並促使室內氣流溫度均勻混合，可使該實驗區域內部之室內溫度變動能控制在±0.5 ℃左右之範圍內。
並列摘要
This research simulates and analyzes the airflow in the experimental area of a national research center. According to the field measuring results of the air-conditioning system, boundary conditions of computational fluid dynamics (CFD), can be deduced, and the airflow simulation can then be simulated according to the actual conditions of the present space under various design cases. The air side performance is predicted to provide assists and evidence in air-conditioning engineering. The function of an air supplying system depends on the shapes and positions of the air outlets. Many researches show that in isothermal jet the throw is related to the mean surface velocity of the outlet, and the jet distance is related to the velocity, volume, the mean area of the outlet and the distribution of velocity. Therefore, the evaluation of air-conditioning space focuses on the parameters of the air supplying system. The goal of this research aims to ensure that the precision instruments in the research space air in an environment with constant temperature and humidity to avoid errors due to temperature fluctuations, and discuss the environmental temperature stability in a large space under the minimum temperature fluctuation. Via the numerical simulation and analysis and the concept of air-conditioning system design, a design solution is proposed that fits the requirements to improve the conditioning system. The basic concept is to use raised temperature air supply (lowered the temperature difference between the space and the supply air), appropriate outlets layouts and high air displacement rate (increasing the supply air flow rate) to take the sensible energy load away, make the air well mixed, and control the temperature fluctuation within ±0.5 ℃.