Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2823
標題: 可攜式安全閥測試容器之體積合適性研究
Study on the Volume Suitability of Portable Test Vessel for Safety Valve
作者: 賴俊發
Lai, Jiun-Fa
關鍵字: 測試容器;Test Vessel;可攜式;噴降;超壓;Portable;Blow-down;Over-pressure
出版社: 機械工程學系所
引用: [1] API Recommended Practice 576 Inspection of Pressure-relieving Devices “Annex A (informative) Pressure-relief Valve Testing”, Third Edition, November 2009, p55-57 [2] Chemical Process Safety Chapter 10 The Role of Mechanical Integrity in Chemical Process Safety “In-House Testing Safety Relief Valves”, p230-238 [3] ASME Performance Test Codes 25 Pressure Relief Devices “4-2.10 General Features of Tests” , An American National Standard, 2008, p18 [4] Sanders, R. E. and Woolfolk, W. H., “Process Safety Relief Valve Testing,” Chemical Engineering Progress, Mar. 1984, pp60–64 [5] Sanders, R. E. and Woolfolk, W. H., “Dynamic Testing and Maintenance of Safety Relief Valves,” Chemical Engineering, Oct. 26, 1987, pp119–124 [6] API STANDARD 526 Flanged Steel Pressure relief Valves 6O rifice Areas and Designations “Table 1—Standard Effective Orifice Areas and Letter Designations” Sixth Edition, APRIL 2009, p2 [7] The National Board Inspection Code (NB-23) Part 3 Repairs and Alterations ,Section 6 Supplement 8 “Recommended Guide for the Design of a Test System for Pressure”2007 , p206-208 [8] 中華民國國家標準 CNS 9969 B2742 “防止超壓之安全裝置-第1部:安全閥”民國101年9月14日公佈 [9] 行政院勞工委員會 危險性機械及設備檢查資訊管理系統 http://inspm.cla.gov.tw/dgmchk/gov_index.aspx [10] Robert W. Fox、Alan T. McDonald、Philip J. Pritchard Introduction to fluid mechanics原著, 黃和順、何正義、曾慶祺、廖基堯編譯, 流體力學 “第10章 可壓縮流的介紹”, 全華圖書股份有限公司印行, p717-722 [11] ASME Boiler and Pressure Vessel Code Sections Ⅷ Rules for Construction of Pressure Vessels Division 1 G-27(c)(1) ,2010 ,p19-20 [12] ASME Boiler and Pressure Vessel Code Sections Ⅷ Rules for Construction of Pressure Vessels Division 1 UG-32(d) ,2010 ,p29-30 [13] ASME Boiler and Pressure Vessel Code Sections Ⅷ Rules for Construction of Pressure Vessels Division 1 UG-99(c) ,2010 ,p74-76 [14] ASME Performance Test Codes 19.2 Pressure Measurement “Section 4 Calibration and Standards”, An American National Standard, 2010 ,p36 [15] 壓力擷取軟體由「惠達科技股份有限公司」提供 [16] API Recommended Practice 574 Inspection Practices for Piping System Components “Table1-Nominal Pipe Sizes (NPSs), Schedules, Weight Classes, and Dimensions of Steel Pipe”, November 2009 ,p9-14 [17] 安全閥測試授課教材 “安全閥作動性能實施要點”中華壓力容器協會, p90-104 [18] Jordan Hill, The Safety Relief Valve Handbook “Chapter 5 Design Fundamentals ”Edition 2009 [19] 安全閥及過壓閥之安全確認型裝置改進研究-蒸氣鍋爐之安全閥 “第二節 安全閥專有名詞解釋” 勞工安全衛生研究報告 , 民國88年10月, p19-27 [20] 方世榮 博士著 統計學導論 “6.6常態分配” 華泰文化事業公司 ,西元2001年06月, p216-221
摘要: 
本研究最主要目的是安全閥測試容器體積之合適性研究。當設備壓力發生異常超壓時安全閥能夠迅速保護設備不致因超壓而爆裂,故安全閥是壓力容器設備上最重要的壓力釋放裝置。經使用一段期間後安全閥應進行測試調校,從壓力容器設備上拆卸後,即交由專業測試廠商進行校驗;然而對於安全閥實施現場測試時,則需要使用可攜式測試容器實施性能測試。目前使用可攜式測試容器之體積皆不相同,為提供安全閥測試容器體積之合適性,以達到有效且便利之校驗,因而進行本次論文研究。
本文研究以質量守恆 (Conservation of Mass) 為基礎,假設進入噴嘴 (Nozzle) 流體為絕熱膨脹過程,用一維穩態可壓縮無黏性等熵流體 (One-dimensional Compressible, Inviscid, Isentropic) 觀念,以理想氣體連續方程式與能量方程式為基礎,當噴嘴喉部達窒流 (Choked) 時安全閥噴降量與測試容器體積消耗質量流率相互關係,推導出噴降時間。
從實際擷取噴降壓力曲線(Blowdown pressure curve ),將曲線區分為噴降 (blowdown) 過程的尖銳驟降(acute down ) 或驟升 (acute upper)、不規律性跳動 (irregularity runout)、顫振跳動(Chatter) 及緩降跳動 (runout);與閥盤閉合前的不規律跳動及規律性跳動等情形,噴降壓力曲線應避免不規律跳動及顫振現象,會損傷閥盤及閥座;另理論與各測試模組噴降時間比較結果時間皆符合超壓 (Overpressure) 範圍要求,應用該理論設計測試容器體積,由於選擇可攜式因素,重量則為另一重要要求,因此達到噴降壓力曲線、理論設計及重量要求,即符合可攜式安全閥測試容器之體積合適性。

The purpose of this study is focused on the volume suitability of portable test vessel for a safety valve. When the pressure within the container has reached its limit, the safety valve quickly releases the excess pressure to protect the container from explosion due to overpressure; therefore, the safety valve is very important pressure equipment on the high pressure container. The safety valve should be removed from the test vessel and calibrated by the licensed manufacture or institution periodically; and it is convenient to have a portable testing equipment for the on-site inspection or test. Therefore, the volume suitability of the portable vessel for safety valve is needed to increase the accessibility of the on-site testing and will be the focus of the present study.
By assuming a steady, one-dimensional, inviscid and compressible flow with isentropic process through a convergent-divergent nozzle, the control volume analysis based on the mass conservation and the energy equations is employed to derive the time elapse of a specific blown-down condition for various sizes and shapes of the pressure vessel. The theoretical predictions and the experimental results will be compared to make a proper decision on the volume and shape suitability for the purpose of on-site testing. By retrieving the blown-down pressure curve, there are various processes such as "acute drop", "acute rise", "irregular run-out", "chattering", "run-out" and irregular run-out and regular oscillation before the disk of the pressure valve closes. The irregularity run-out and chatter of the blown-down pressure curve shall be avoided in order not to damage the disk and the valve seat of the safety valve. The blown-down pressure curves based on the theoretical predictions and the experiments coincide quite well with suitable overpressure. Among the models tested, the volume suitability of the pressure vessel is selected based on examining the characteristics of blown-down pressure curve and the size or weight of the vessel.
URI: http://hdl.handle.net/11455/2823
其他識別: U0005-2307201312201800
Appears in Collections:機械工程學系所

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