本文針對三太造機廠股份有限公司製造並於用大潭電廠以及通霄電廠的立式泵浦分別以有限元素法分析其於靜止且腔內無水下的自然頻率，並觀察自然頻率所對應的模態。針對通霄電廠立式泵浦(設計中)詳細分析，加以判斷立式泵浦整體的自然頻率是否靠近或位於運轉頻率的百分之二十之內，以及泵浦於運轉時可能發生的振動問題。對大潭立式泵浦以及臥式泵浦進行加速規量測實驗，並且將實驗結果與模擬結果進行比對，加以驗證模擬的準確性。

綜合各分析的結果，大潭與通霄泵浦由於結構上相似，因此有類似的自然頻率趨勢。相較於大潭，通霄泵浦更細更長因此更容易在低頻產生問題。本研究建議改善方案一、二，以及三太公司所提供的改善方案(本文歸於改善方案三)，分別為使用肋或連接零件於保護管及水柱管之間的不同位置；模擬結果顯示方案二有最佳的改善效果，方案一與三因肋架裝設位置不同，方案一相較於三有較佳的改善結果，但皆能改善頻率位置，且提升泵浦本位於較低的共振頻率及振動現象。使用方案一、二改善後泵浦整體自然頻率提高，使得共振頻率超出泵浦馬逹運轉頻率的百分二十之外，然而使用方案三的模擬頻率結果雖有提高，但仍然在運轉頻率的百分二十之內。

臥式及立式泵浦加速規量測部分可以發現實驗與模擬在幾個共振頻率上皆能相互對應，由此可以驗證有限元素模擬的準確性。立式泵浦加速規量測因敲擊撼動力不足，因此實驗與模擬對應頻率為泵浦高頻的局部振動部分。

In this paper, the finite element method has been used to analyze vertical pumps with no liquid in chamber which have been manufactured by San Tai machinery manufacturing company for Tam and Tunghsiao power plant. The simulation results are used to determine the vibration characteristics of the pumps which are whether the pump structural natural frequency is close to twenty percent of operation speed frequency or not. In order to verify the accuracy of the simulation, acceleration measurement experiment had been made on the vertical pump and the horizontal pump.

From the simulation results, vertical pumps natural frequencies has similar tendencies because of their similar structure. Tunghsiao vertical pump is weaker than Tam vertical pump because its structure is thinner and longer than Tam. There are three different cases designed in this paper to improve the pump by using the ribs or connecting element between protected pipe and main pipe in different locations. The simulation results show that the pump in case 2 has the best improvement effect. Pump improvement effect in Case1 is better than case 3, because rib connect elements in lower position. In Case 1 and 2, the stiffness of the pump increase and their natural frequencies are successful avoided within the twenty percent of operation frequency. In Case 3, structure natural frequencies increase, but some of them are still close to the operation frequency. Several natural frequencies in acceleration measurement experiment can match to simulation results. Since we can’t have enough power to shake vertical pump structure in impact experiment, only the parts of high frequencies with local vibration can correspond to simulation results

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