- 學位論文
針閥之熱流與固體形變耦合數值模擬分析
A Study on Numerical Simulation of Needle Valve by Coupling Thermoflow with Heat Deformation
摘要
高壓針閥系統的耐用性與效能的研究之議題對於工業界管排傳輸運用領域中佔有極重要的地位，因此對於針閥的熱與流量分析之課題日受關注。然而一些針閥的基本性能指標，如流量係數Cv、溫度壓力條件下對針閥之變形量影響，通常都是透過實際實驗量測獲得，且這些進行高壓流量測試或是高溫高壓變形量測的實驗流程與設備架設，都是相當時間與花錢的。 本研究中利用PTC Creo 和 ANSYS兩個商用計算軟體，計算在不同的壓力操作下的流量係數Cv與溫度壓力作用在針閥之最大容許溫度，利用數值模擬簡化實驗流程。由數值模擬分析顯示，驗證在流量係數Cv的數值解與實際實驗量測誤差在3%以內。此外流量係數對於操作壓力並不敏感，這顯示合乎本研究最初之假設在低壓裝置中執行流量係數的量測能獲得相同之結果。
並列摘要
The durability and accountability of the needle valves used in high pressure piping systems (up to 10,000 psig) are important in industrial application. Thermal and flow analysis and measurements of the needle valves have drawn attentions increasingly. Especially, the flow factor Cv and relationship between temperature and pressure which are often obtained by measurements, are the essential performance indexes of the valve. However, it is time and money consuming to set up an experimental apparatus to perform the high pressure flow measurements. Therefore, two commercial computational packages, the PTC Creo and ANSYS, are used to calculate the flow factors under different operation pressures and the maximum allowable temperature with different operation pressures and temperature to the needle valves in the present study. The numerical results indicated that the error between numerical solutions and experiments are within 3%. In addition, the flow factors for various valves are not sensitive to the operation pressure, which indicated that the measurement of the flow factor can be performed in a low pressure apparatus.