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編號(hào)
無(wú)錫太湖學(xué)院
畢業(yè)設(shè)計(jì)(論文)
相關(guān)資料
題目: 過(guò)濾器的設(shè)計(jì)及運(yùn)動(dòng)仿真
信機(jī) 系 機(jī)械工程及自動(dòng)化專業(yè)
學(xué) 號(hào):
學(xué)生姓名:
指導(dǎo)教師: (職稱:副教授)
(職稱: )
2013年5月25日
目 錄
一、畢業(yè)設(shè)計(jì)(論文)開(kāi)題報(bào)告
二、畢業(yè)設(shè)計(jì)(論文)外文資料翻譯及原文
三、學(xué)生“畢業(yè)論文(論文)計(jì)劃、進(jìn)度、檢查及落實(shí)表”
四、實(shí)習(xí)鑒定表
無(wú)錫太湖學(xué)院
畢業(yè)設(shè)計(jì)(論文)
開(kāi)題報(bào)告
題目: 過(guò)濾器的設(shè)計(jì)及運(yùn)動(dòng)仿真
信機(jī) 系 機(jī)械工程及自動(dòng)化 專業(yè)
學(xué) 號(hào):
學(xué)生姓名:
指導(dǎo)教師: (職稱:副教授)
(職稱: )
2012年11月25日
課題來(lái)源
該課題來(lái)源于石油化工、食品、醫(yī)藥等領(lǐng)域?qū)﹄s質(zhì)過(guò)濾效率和生產(chǎn)成本的開(kāi)發(fā)需求。
科學(xué)依據(jù)(包括課題的科學(xué)意義;國(guó)內(nèi)外研究概況、水平和發(fā)展趨勢(shì);應(yīng)用前景等)
一、科學(xué)意義
目前,我國(guó)很多企業(yè)使用傳統(tǒng)過(guò)濾器,這種過(guò)濾器在過(guò)濾持續(xù)過(guò)程中,過(guò)濾面積小使得液體中固態(tài)雜質(zhì)被過(guò)濾元件表面,過(guò)濾效率下降。
復(fù)合型袋式精細(xì)過(guò)濾器與普通過(guò)濾器相比,在同樣殼體、容積的情況下,該過(guò)濾器過(guò)濾面積相對(duì)大60%以上,這樣裝置運(yùn)行周期長(zhǎng),停車(chē)時(shí)間短,有效降低運(yùn)行成本;在相同處理量的情況下,該過(guò)濾器過(guò)濾面積較普通過(guò)濾器大,意味著設(shè)備容積就可以做小,可以節(jié)省設(shè)備投資20%以上,有效降低設(shè)備的制造成本。傳統(tǒng)的過(guò)濾器生產(chǎn)能力低,使用周期短,生產(chǎn)成本高。因此需要對(duì)此裝置進(jìn)行改進(jìn)與創(chuàng)新,提高使用周期,減少停車(chē)次數(shù),能夠提高生產(chǎn)產(chǎn)量和產(chǎn)品質(zhì)量。
2、 國(guó)內(nèi)外研究情況、水平和發(fā)展趨勢(shì)
近年來(lái)國(guó)內(nèi)外研制了各式各樣的過(guò)濾器,產(chǎn)品的用途和性能都不同。目前就我國(guó)的高效空氣過(guò)濾器市場(chǎng)需求量已接近每年10萬(wàn)臺(tái),占國(guó)際市場(chǎng)的2%~4%,市場(chǎng)份額大。六十年代,我國(guó)一些科研部門(mén)對(duì)精密過(guò)濾器進(jìn)行了小規(guī)模的試驗(yàn)和應(yīng)用,但基本上沒(méi)有形成工業(yè)規(guī)模的生產(chǎn)能力。70年代末期,上海醫(yī)藥工業(yè)研究院等單位對(duì)精密過(guò)濾器進(jìn)行了教系統(tǒng)的研究。迄今為止,國(guó)內(nèi)已有了商品化的精密過(guò)濾器,其中生產(chǎn)最多的品種是混合纖維素濾膜。
新型復(fù)合袋式過(guò)濾器采用新型過(guò)濾元件,該元件是由二個(gè)高性質(zhì)的同心圓筒,使用獨(dú)特的制造工藝制作成一個(gè)封閉的濾筒和濾袋。過(guò)濾面積大、納污容量強(qiáng)、按國(guó)際通用的美國(guó)GAF標(biāo)準(zhǔn)的濾袋就擴(kuò)大了60%的過(guò)濾面積。
3、 應(yīng)用前景
復(fù)合袋式過(guò)濾器廣泛應(yīng)用于石油化工、精細(xì)化工、化纖、制藥、石墨、食品、飲料及雙氧水等方面的過(guò)濾。過(guò)濾精度從1至1000μm,處理量從1至1000m3/h的液體過(guò)濾。
研究?jī)?nèi)容
該新型復(fù)合袋式過(guò)濾器根據(jù)工作壓力,溫度等因素設(shè)計(jì)相應(yīng)的型號(hào),工作介質(zhì)進(jìn)入新型復(fù)合式過(guò)濾袋內(nèi),從過(guò)濾的兩面進(jìn)入容器內(nèi),然后流出濾器,過(guò)濾下來(lái)的殘留物留在過(guò)濾袋內(nèi)部。工作一段時(shí)間后,濾袋外表面形成濾餅造成差壓,當(dāng)達(dá)到設(shè)定差壓時(shí),應(yīng)停止工作,進(jìn)行清洗。該器械在國(guó)內(nèi)為高端技術(shù)產(chǎn)品,并有著廣泛的應(yīng)用。
根據(jù)設(shè)計(jì)要求,運(yùn)用二維、三維建模軟件進(jìn)行設(shè)計(jì),完成總裝配,并對(duì)總體機(jī)構(gòu)進(jìn)行運(yùn)動(dòng)仿真。設(shè)計(jì)出比較合理的加工工序和工藝方案及繪制工序圖,用軟件對(duì)此機(jī)器繪制零件圖并裝配。
擬采取的研究方法、技術(shù)路線、實(shí)驗(yàn)方案及可行性分析
1、 研究方法、技術(shù)路線、實(shí)驗(yàn)方案
通過(guò)閱讀有關(guān)資料、文獻(xiàn)、收集、篩選、整理課題研究所需要的有關(guān)數(shù)據(jù)、理論依據(jù),綜合運(yùn)用所學(xué)理論研究論文課題。進(jìn)一步加強(qiáng)軟件學(xué)習(xí),為三維設(shè)計(jì)與運(yùn)動(dòng)仿真打下良好的基礎(chǔ)。了解熟悉SW6-1998.V6.0過(guò)程設(shè)備強(qiáng)度計(jì)算軟件,零部件計(jì)算程序可單獨(dú)計(jì)算最為常用的受內(nèi)、外壓的圓筒和各種封頭,以及開(kāi)孔補(bǔ)強(qiáng)、法蘭等受壓元件,也可對(duì)HG20582-1998《鋼制化工容器強(qiáng)度計(jì)算規(guī)定》中的一些較為特殊的受壓元件進(jìn)行強(qiáng)度計(jì)算。
2、 可行性分析
通過(guò)對(duì)論文課題的學(xué)習(xí)研究達(dá)到鞏固、擴(kuò)大、深化已學(xué)理論知識(shí)、提高思考分析解決實(shí)際問(wèn)題等綜合素質(zhì)的目的。并對(duì)三維設(shè)計(jì)軟件和SW6-1998.V6.0過(guò)程設(shè)備強(qiáng)度計(jì)算軟件更深層次的學(xué)習(xí)鞏固。
研究計(jì)劃及預(yù)期成果
研究計(jì)劃:
2012年11月23日-2012年12月25日:按照任務(wù)書(shū)要求查閱論文相關(guān)參考資料,填寫(xiě)畢業(yè)設(shè)計(jì)開(kāi)題報(bào)告書(shū)。
2012年12月26日-2010年1月10日:填寫(xiě)畢業(yè)實(shí)習(xí)報(bào)告。
2013年1月11日-2013年1月25日:按照要求修改畢業(yè)設(shè)計(jì)開(kāi)題報(bào)告。
2013年1月26日-2010年2月10日:學(xué)習(xí)并翻譯一篇與畢業(yè)設(shè)計(jì)相關(guān)的英文材料。
2013年2月11日-2013年4月11日:對(duì)SW6-1998.V6.0過(guò)程設(shè)備強(qiáng)度計(jì)算軟件的學(xué)習(xí)研究,確定過(guò)濾器的型號(hào),設(shè)計(jì)計(jì)算設(shè)備參數(shù),完成整體設(shè)計(jì)計(jì)算。
2013年4月12日-2013年4月20日:運(yùn)動(dòng)仿真計(jì)。
2013年4月21日-2013年5月15日:畢業(yè)論文撰寫(xiě)和修改工作。
預(yù)期成果:
符合壓力容器設(shè)計(jì)標(biāo)準(zhǔn),得到合理的設(shè)計(jì)數(shù)據(jù),完成整體設(shè)計(jì)參數(shù),并能完成運(yùn)動(dòng)仿真,分析運(yùn)動(dòng)特征。
特色或創(chuàng)新之處
1、使用快開(kāi)設(shè)計(jì),密封性能好,濾袋更換方便。
2、介質(zhì)通量大,壓降低,設(shè)備體積小,投資省。
3、過(guò)濾面積大,納污量強(qiáng),濾袋更換周期長(zhǎng)。
已具備的條件和尚需解決的問(wèn)題
已經(jīng)初步具備二維設(shè)計(jì)的基礎(chǔ)知識(shí),運(yùn)用AutoCAD可以完成。已經(jīng)了解了新型復(fù)合袋式過(guò)濾器的結(jié)構(gòu)和基本功能以及整體的裝配過(guò)程,并能完成整體計(jì)算?,F(xiàn)在需要對(duì)SW6-1998.V6.0過(guò)程設(shè)備強(qiáng)度計(jì)算軟件的深入學(xué)習(xí),對(duì)三維建模與運(yùn)動(dòng)仿真的設(shè)計(jì)把握還不夠。
指導(dǎo)教師意見(jiàn)
指導(dǎo)教師簽名:
年 月 日
教研室(學(xué)科組、研究所)意見(jiàn)
教研室主任簽名:
年 月 日
系意見(jiàn)
主管領(lǐng)導(dǎo)簽名:
年 月 日
英文原文
The Achievements on the Technology of the Pressure Vessels
Abstract Recently European and U.S have issued their pressure equipment codes. Especially in the pressure vessel code, The EN 13445 from European and the ASME VIII-2 2007 from U.S significantly changed the technical contents and hand out the new design model and the methods on the foundation of a grand scale research.
Key Words Pressure Vessels Technology Progress
A. Introduction
Now the whole world has entered a period of economy globalization. Standard internationalization is an inexorable trend of economic globalization. The characteristics of development trend of current standard technology are as follows:
1. Design method against failure mode;
2. Widely application of computer technology;
3. More economic construction methods;
4. Technical specification which reflected comprehensive construction technology;
5. More wide application range of product specification.
6. To seek national competitive capacity in international trade.
B. Development in Pressure Vessel Design Technology
1. Technology Development in Materials Used for Pressure Vessels
In recent years, It is obvious, that the pressure vessel products are getting larger and larger and with high technical references. Nowadays, the main research achievement and technical progress in pressure vessel materials are as follows:
2. Development in Design Technology
Modern structure design for pressure vessel is getting rid of the traditional concept step by step, to reflect the design concept with can satisfy technology requirement. In the view of failure mode, under the prerequisite of safety, actual result, safety and economic benefit are combined harmoniously.
(1)Design Method in Accordance With Failure Mode:
Synthesizing the technical standard of main industrial countries in the world, consulting the content of European standards, the international standard ISO 16528 classifies the common failure modes of boilers and pressure vessels into 3 classes and 14 kinds, that clearly defines the design technical application concept against failure modes:
Short term failure modes:
l Brittle fracture
l Ductile rupture
l Leakage at joints due to excessive deformations
l Crack formation or ductile tearing due to excessive local strains
l Instability– elastic, plastic or elastic-plastic
Long term failure modes:
l Creep Rupture
l Creep - excessive deformations at mechanical joints or resulting in unacceptable transfer of load
l Creep instability
l Erosion, corrosion
l Environmentally assisted cracking e.g. stress corrosion cracking, hydrogen induced cracking, etc
Cyclic failure modes:
l Progressive plastic deformation
l Alternating plasticity
l Fatigue under elastic strains (medium and high cycle fatigue) or under elastic-plastic strains (low cycle fatigue)
For pressure equipment standard, at least the following failure modes must be considered in definition of design criterion and methods:
l Brittle fracture
l Ductile rupture
l Leakage at joints
l Elastic or plastic instability
(2)Complicate Constitutive Relationship and Structure
Along with the rapid development of computer capacity, now the pressure vessel design technology already can solve the problems about very complicate constitutive relationship or engineering with complicate structure. such as:
l Materials with different specification in different direction: composite materials, fiber winding pressure equipment;
l Combined structure analysis design: closed structure combined by flanges, gaskets and bolts, contact of multilaminate shells;
l Buckling and back buckling of complicate structure: stability analysis of large poles and combined structure of shell;
l Dynamic response of combined structure: earthquake response, piping vibration fluid inducting vibration, etc.
(3) Large-Scale Numerical Value Analysis
Traditional computer aided design (CAD) has already transited into Computer aided engineering (CAE) step by step.
(4) Analysis of Multi-Physical Field Coupling
For modern pressure equipment, the interaction between fluid and solid must be solved exactly, at the same time, thermal analysis and impact analysis are indispensable technical methods. Therefore, the following problems must be solved too:
l Coupling of fluid and solid: large vessels, transportation tanks, flowing inside piping
l Multi phase flowing: boiler combustion, combustion and reflection of fluidized bed
l Heat transfer and medium: plate heat exchanger, efficiency of column plate, efficiency of distributor.
l Impact load: water-hammer phenomenon, impact
(5) Method to Change Safety Coefficient
In order to increase the competition of home made products, it is a universal trend for countries and regions all over the world to decrease the safety coefficient. The US standard (ASME) and European unified standard for pressure vessels (under making) also decreased relative safety coefficient. In ASME Code Sec. VIII Div. 1 (2007 edition) nb has been decreased to 3.5 from 4.0. And in ASME Code Sec. VIII Div. 2 (2007 edition) nb has been decreased to 2.4 from 3.0[4]. While the minimum value of nb in European unified standard for pressure vessels is 1.875. In Chinese new edition of Safety Technology Supervision Rules for Pressure Vessel , safety coefficient has been decreased to 2.7. from 3.0[5], safety coefficient nb designed in accordance with analysis design method has been decreased to 2.4 from 2.6, the relative technical standard GB 150 and JB 4732 will be adjusted too.
(6) Structure Change Due to Safety Concept
In modern pressure vessel design, the designers have to consider not only safety and technology requirement but also environment protection and saving resources.
C. Developing Trend of International Pressure Equipment Standard Technology
The developing trend of international pressure equipment standard technology has the following feathers:
1. Coordination between Technical Rules and Technical Standards:
State technical rules are mandatory rules established by the government to guarantee the safety of pressure vessels products, products within its jurisdiction have to obey its safety principles, while technical standards are recommended, they stipulate relative technical index for products quality to guarantee the safety of pressure vessels products. but the technical index stipulated by the standards must be in accordance with safety principles of the rules. Technical standards may be used to guide design, construction, inspection and acceptance of pressure vessels, they are the platform of technical assessment between pressure vessel product construction and trade.
2. Research for Basic Properties of Pressure Vessel Materials:
(1) Low Temperature Impact Properties: to research the laws of materials low temperature impact properties influenced by materials size, conditions, thickness and stress state, to arise the determining method of allowed lowest design metal temperature (MDMT) for Chinese technical standard in accordance with the performance of Chinese materials and rules of breaking mechanics
(2) Chart for Determining Shell Thickness of Components under External Pressure: to study stress-stain relationship of pressure vessel materials in common use., to establish calculating method tangential elastic modulus of materials in plastic phase, to arise charts for determining shell thickness of components under external pressure
(3) Testing Technology for Materials Properties of Micro Samples: to establish testing center for micro samples, to study visual technology for small punch test, micro sample test as well as test process, to provide technical support for safety evaluation and life analysis of pressure vessels
3. Study for Design Method of Pressure Vessels
(1) Failure Mode: to study the pressure typical failure mode of pressure vessels as well as its mechanism and criterion; to establish design rules in the base of failure mode; to guarantee intrinsic safety of pressure vessels;
(2) Design Method based on Failure Mode: to arise calculation method for plastic collapse load of pressure vessels with complex structure against five main failure mode as general plastic deformation failure, increasing plastic deformation failure, out of static failure, fatigue failure and static balance failure with consideration of thermal load, mechanical load , varied load and their combination; to make known the relationship between partial failure stain and stress; arise sub-safety coefficient; to establish design evaluation method for pressure vessels on the base of failure modes;
(3) Design Method for Sealing Structure on the Base of Leakage Rate: to study design method of large diameter and high pressure, evaluation method for sealing effectiveness of sealing structure and design method for sealing structure on the base of leakage rate.
(4) Digital Design Method for Pressure Vessels without Life Limit: to establish simulating center of pressure vessels; through study for simulation of structure and materials properties , coupling (inter-action of fluid-structure, soil-structure –fluid ), extend pressure vessel operation from normal operation to safety operation with high efficiency in its life without limit (comprehensive consideration of construction, manufacture, operation, maintain abandon); to increase creating design capacity and technical lever of pressure vessels; to decrease testing times; to speed up development of pressure vessels;
4. Study for Key Technology of Pressure Vessel Manufacture
(1) Welding: to study forecasting and control methods of residual stress; method of defect inspection, evaluation and control;
(2) Heat Treatment: To study materials and equipments performance regulation effected by heat treatment; to establish forecasting, inspecting and evaluating methods for heat treatment effect, through systematic study in creating mechanism, inspecting method and decreasing method of residual stress.
5. Study of Pressure Vessels Made of Special Materials
(1) Pressure Vessels Made of Composite Materials: to study properties of composite materials,design and inspecting methods of pressure vessels made of composite materials;
(2) Pressure Vessels made of special Materials: to study technology of design, heat treatment, welding, structural optimization and quality control of pressure vessels made of special materials, such as biphase stainless steel, nickel base alloy, zirconium, stainless steel with nitrogen, etc.
6. Pressure Vessels Inspection Based on Failure Mode
(1) Study Forecasting and Inspecting Methods for complex fluid corrosion of High Temperature and High Pressure Vessels: mechanism and forecasting method of for complex fluid corrosion of High Temperature and High Pressure Vessels; live diagnosis and supervision of fluid corrosion; optimization technology of periodic inspection based on forecasting of fluid corrosion
(2)To Study degrading process, regulation, mechanism and inspection of materials servicing under extreme conditions such as high temperature, high pressure, multi-phase fluid Materials, neutron irradiation etc as well as its life forecasting technology.
7. To study further technical index of Chinese materials, design calculation methods, manufacture and inspection requirements, especially for accumulation and contrast of basic properties. To win standards international mutual recognition.
中文譯文
壓力容器技術(shù)進(jìn)展
摘 要:近期歐洲和美國(guó)相繼頒布了新的承壓設(shè)備標(biāo)準(zhǔn),特別是在壓力容器領(lǐng)域,歐洲的EN13445[1]和美國(guó)的ASME VIII-2 2007[2]全面整理和改編了原有的技術(shù)內(nèi)容,在大規(guī)模研究的基礎(chǔ)上提出了全新的壓力容器建造理念和設(shè)計(jì)方法。本文將簡(jiǎn)要介紹目前壓力容器技術(shù)的技術(shù)進(jìn)展,同時(shí)討論我國(guó)壓力容器設(shè)計(jì)技術(shù)領(lǐng)域的發(fā)展方向和需要深入研究的課題。
關(guān)鍵詞:壓力容器 技術(shù) 進(jìn)展
一、引言
世界已經(jīng)進(jìn)入了經(jīng)濟(jì)全球化的發(fā)展時(shí)期,經(jīng)濟(jì)全球化的一個(gè)必然趨勢(shì)是標(biāo)準(zhǔn)的國(guó)際化。隨著國(guó)際資本進(jìn)入中國(guó)建設(shè)大型工程裝置和國(guó)內(nèi)企業(yè)擴(kuò)大生產(chǎn)裝置能力,國(guó)際化的工程項(xiàng)目給我國(guó)的壓力容器行業(yè)帶來(lái)了國(guó)際上最先進(jìn)的技術(shù)和管理模式,已經(jīng)不可避免地給我國(guó)的壓力容器行業(yè)提出了國(guó)際競(jìng)爭(zhēng),建造大型和高參數(shù)壓力容器的機(jī)會(huì)與挑戰(zhàn)。
事實(shí)上這些裝置的建設(shè)需求是壓力容器行業(yè)發(fā)展的動(dòng)力,是發(fā)展我國(guó)壓力容器行業(yè)的最好時(shí)機(jī),也是和世界先進(jìn)技術(shù)和管理方式融合的最好時(shí)機(jī)。因此研究壓力容器建造技術(shù)和使用最先進(jìn)的技術(shù)手段,提高國(guó)家的整體國(guó)際競(jìng)爭(zhēng)力是目前行業(yè)關(guān)注的焦點(diǎn)。
壓力容器是一個(gè)涉及多行業(yè)、多學(xué)科的綜合性產(chǎn)品,其建造技術(shù)涉及到冶金、機(jī)械加工、腐蝕與防腐、無(wú)損檢測(cè)、安全防護(hù)等眾多行業(yè)。隨著冶金、機(jī)械加工、焊接和無(wú)損檢測(cè)等技術(shù)的不斷進(jìn)步,特別是以計(jì)算機(jī)技術(shù)為代表的信息技術(shù)的飛速發(fā)展,帶動(dòng)了相關(guān)產(chǎn)業(yè)的發(fā)展,在世界各國(guó)投入了大量人力物力進(jìn)行深入的研究的基礎(chǔ)上,壓力容器技術(shù)領(lǐng)域也取得了相應(yīng)的進(jìn)展。為了生產(chǎn)和使用更安全、更具有經(jīng)濟(jì)性的壓力容器產(chǎn)品,傳統(tǒng)的設(shè)計(jì)、制造、焊接和檢驗(yàn)方法已經(jīng)和正在不同程度地為新技術(shù)、新產(chǎn)品所代替,而冶金、機(jī)械加工、焊接和無(wú)損檢測(cè)等壓力容器相關(guān)行業(yè)的技術(shù)進(jìn)步,是壓力容器行業(yè)整體技術(shù)水平提高的前提條件。
技術(shù)發(fā)展的動(dòng)力在于經(jīng)濟(jì)的競(jìng)爭(zhēng)。經(jīng)濟(jì)全球化和激烈的競(jìng)爭(zhēng)使得世界各國(guó)必須考慮壓力容器的安全性和經(jīng)濟(jì)性的和諧統(tǒng)一,因此新的設(shè)計(jì)、建造方法不斷出現(xiàn),對(duì)壓力容器的技術(shù)研究也在不斷深入。
當(dāng)前壓力容器技術(shù)的發(fā)展趨勢(shì)有如下特點(diǎn):
1. 針對(duì)失效模式的設(shè)計(jì)方法;
2. 計(jì)算機(jī)技術(shù)的廣泛應(yīng)用;
3. 更經(jīng)濟(jì)的設(shè)計(jì)、制造方法;
4. 體現(xiàn)綜合建造技術(shù)的技術(shù)要求;
5. 更廣的標(biāo)準(zhǔn)適用范圍;
6. 謀求在國(guó)際貿(mào)易中的國(guó)家競(jìng)爭(zhēng)力。
本文重點(diǎn)討論設(shè)計(jì)技術(shù)的進(jìn)展,結(jié)合我國(guó)的現(xiàn)狀,提出關(guān)于標(biāo)準(zhǔn)技術(shù)的研究方向。希望行業(yè)內(nèi)能夠充分重視我國(guó)在設(shè)計(jì)技術(shù)上與先進(jìn)國(guó)家的差距,提高設(shè)計(jì)水平,提高全行業(yè)的國(guó)際競(jìng)爭(zhēng)力。
二、壓力容器設(shè)計(jì)技術(shù)進(jìn)展
1 、壓力容器用材料的技術(shù)進(jìn)展
近年來(lái)壓力容器產(chǎn)品大型化、高參數(shù)化的趨勢(shì)日益明顯,千噸級(jí)的加氫反應(yīng)器、二千噸級(jí)的煤液化反應(yīng)器、一萬(wàn)立方米的天然氣球罐、大直徑的長(zhǎng)輸管線和超超臨界動(dòng)力鍋爐等已經(jīng)在我國(guó)大量應(yīng)用,壓力容器在電力、石油化工、核工業(yè)、煤化工等領(lǐng)域中的應(yīng)用場(chǎng)合也日益苛刻。因此,耐高溫、高壓和耐腐蝕的壓力容器用材料的研制與開(kāi)發(fā)一直是壓力容器行業(yè)所面臨的重大課題。
對(duì)此,各國(guó)均投入了大量的人力物力從事相關(guān)的研究工作。目前,壓力容器用材料的主要研究成果和技術(shù)進(jìn)步表現(xiàn)在以下幾個(gè)方面:
l 材料的高純凈度:冶金工業(yè)整體技術(shù)水平和裝備水平的提高,極大地提高了材料的純凈度,提高了壓力容器用材料的力學(xué)性能指標(biāo),提高了壓力容器的整體安全性。歐洲和我國(guó)的標(biāo)準(zhǔn)EN 10028、GB/T 713、GB 19189都提出了更嚴(yán)格的要求;
l 新材料的不斷出現(xiàn)、復(fù)合材料的使用:ASME Codecase 2390-2規(guī)定了復(fù)合增強(qiáng)材料容器的結(jié)構(gòu)設(shè)計(jì)制造檢驗(yàn)要求。但僅僅是不完整的設(shè)計(jì)方法,沒(méi)有包含任意纏繞角度的設(shè)計(jì)方法。
l 材料的介質(zhì)適用性:針對(duì)各種腐蝕性介質(zhì)和操作工況,已研究開(kāi)發(fā)出超級(jí)不銹鋼、雙相鋼、特種合金等金屬材料,使之適合各種應(yīng)用條件,給設(shè)計(jì)者以更多選擇的空間,為長(zhǎng)周期安全生產(chǎn)提供了保證;
l 材料的應(yīng)用界限:針對(duì)高溫蠕變、回火脆化、低溫脆斷所進(jìn)行的研究,規(guī)定材料的氣體含量、J系數(shù)、X系數(shù),準(zhǔn)確地給出材料的應(yīng)用范圍。
l 更高強(qiáng)度材料的應(yīng)用:在設(shè)備大型化的要求下,傳統(tǒng)的材料已經(jīng)無(wú)法解決諸如 3 萬(wàn)立方米天然氣球罐、鋼廠的大型球罐、 20 萬(wàn)立方米原油儲(chǔ)罐、大口徑管線以及超高壓容器的選材問(wèn)題。目前 σ b ≥ 800MPa 的高強(qiáng)容器材料和X80~X100的高強(qiáng)管線用材料的應(yīng)用正在引起國(guó)內(nèi)研究人員的廣泛關(guān)注。
l 深入研究材料的適用范圍,如美國(guó)在確定材料低溫界限的研究中,利用材料的沖擊試驗(yàn)取得的數(shù)據(jù)和經(jīng)驗(yàn),與斷裂力學(xué)的評(píng)價(jià)指標(biāo)關(guān)聯(lián),最終得到相對(duì)合理的材料低溫界限。
l 為了進(jìn)行計(jì)算機(jī)數(shù)值分析,提出了材料相關(guān)性能的數(shù)學(xué)表達(dá)關(guān)系,為今后的結(jié)構(gòu)數(shù)值分析奠定了基礎(chǔ)。
2、設(shè)計(jì)技術(shù)進(jìn)展
現(xiàn)代的壓力容器結(jié)構(gòu)設(shè)計(jì)正在逐步擺脫傳統(tǒng)觀念的束縛,體現(xiàn)真正滿足工藝要求的設(shè)計(jì)理念,追求實(shí)效性、安全性和經(jīng)濟(jì)性的和諧統(tǒng)一。在信息時(shí)代的今天,計(jì)算機(jī)技術(shù)應(yīng)用已經(jīng)滲透到壓力容器行業(yè)的每一個(gè)領(lǐng)域。計(jì)算機(jī)軟、硬件的每一個(gè)進(jìn)步都極大地影響著壓力容器行業(yè)的技術(shù)進(jìn)展。
(1) 以失效模式為依據(jù)的設(shè)計(jì)方法:
ISO 16528[3]綜合世界主要工業(yè)國(guó)家的技術(shù)標(biāo)準(zhǔn)規(guī)定,參照歐洲標(biāo)準(zhǔn)的內(nèi)容,針對(duì)鍋爐和壓力容器常見(jiàn)的失效形式,在標(biāo)準(zhǔn)中將其歸類為三大類、14種失效模式,明確了針對(duì)失效模式的設(shè)計(jì)技術(shù)應(yīng)用理念:
短期失效模式(Short term failure modes):
l 脆性斷裂(Brittle fracture)
l 韌性斷裂(Ductile rupture)
l 超量變形引起的接頭泄露(Leakage at joints due to excessive deformations)
l 超量局部應(yīng)變引起的裂紋形成或韌性撕裂(Crack formation or ductile tearing due to excessive local strains)
l 彈性、塑性或彈塑性失穩(wěn)(垮塌)(Instability– elastic, plastic or elastic-plastic)
長(zhǎng)期失效模式(Long term failure modes)
l 蠕變斷裂(Creep Rupture)
l 蠕變-在機(jī)械連接處的超量變形或?qū)е虏辉试S的載荷傳遞(Creep - excessive deformations at mechanical joints or resulting in unacceptable transfer of load)
l 蠕變失穩(wěn)(Creep instability)
l 沖蝕、腐蝕(Erosion, corrosion)
l 環(huán)境助長(zhǎng)開(kāi)裂如:應(yīng)力腐蝕開(kāi)裂、氫致開(kāi)裂(Environmentally assisted cracking e.g. stress corrosion cracking, hydrogen induced cracking, etc)
循環(huán)失效模式(Cyclic failure modes):
l 擴(kuò)展性塑性變形Progressive plastic deformation
l 交替塑性Alternating plasticity
l 彈性應(yīng)變疲勞(中周和高周疲勞)或彈-塑性應(yīng)變疲勞(低周疲勞)Fatigue under elastic strains (medium and high cycle fatigue) or under elastic-plastic strains (low cycle fatigue)
l 環(huán)境助長(zhǎng)疲勞Environmentally assisted fatigue
對(duì)于壓力設(shè)備標(biāo)準(zhǔn),在確定設(shè)計(jì)準(zhǔn)則和方法中至少要考慮如下失效模式:
l 脆性斷裂(Brittle fracture)
l 韌性斷裂(Ductile rupture)
l 接頭泄露(Leakage at joints)
l 彈性或塑性失穩(wěn)(Elastic or plastic instability)
l 蠕變斷裂(Creep rupture)
(2) 復(fù)雜本構(gòu)關(guān)系和結(jié)構(gòu)
隨著計(jì)算機(jī)能力的飛速發(fā)展,壓力容器設(shè)計(jì)技術(shù)已經(jīng)可以解決具有高度復(fù)雜本構(gòu)關(guān)系或者復(fù)雜結(jié)構(gòu)的工程問(wèn)題如:
l 各向異性的材料:復(fù)合材料、纖維纏繞容器;
l 結(jié)構(gòu)組合分析設(shè)計(jì):法蘭、墊片和螺栓組成的密封結(jié)構(gòu)、多層殼體的接觸問(wèn)題;
l 復(fù)雜結(jié)構(gòu)的曲屈和后屈曲:大型桿、殼組合結(jié)構(gòu)的穩(wěn)定性分析;
l 組合結(jié)構(gòu)的動(dòng)力響應(yīng):地震響應(yīng)、管道振動(dòng),流體誘導(dǎo)振動(dòng)等。
(3) 大規(guī)模數(shù)值分析
傳統(tǒng)的計(jì)算機(jī)輔助設(shè)計(jì)(CAD)已逐步過(guò)渡到計(jì)算機(jī)輔助工程(CAE)。隨著計(jì)算機(jī)能力的不斷增強(qiáng)和分析手段的日益多樣化,設(shè)計(jì)者在結(jié)構(gòu)設(shè)計(jì)階段就可以預(yù)見(jiàn)到諸如焊接過(guò)程中所產(chǎn)生的殘余應(yīng)力、設(shè)備組裝和運(yùn)輸過(guò)程中可能會(huì)出現(xiàn)的碰撞等問(wèn)題,并在設(shè)計(jì)階段消除這些問(wèn)題,分析設(shè)計(jì)和結(jié)構(gòu)優(yōu)化設(shè)計(jì)已經(jīng)逐漸為設(shè)計(jì)者所掌握。
計(jì)算機(jī)硬件技術(shù):技術(shù)發(fā)展方向的大型計(jì)算機(jī)、多CPU并行計(jì)算系統(tǒng)。計(jì)算軟件全面發(fā)展,針對(duì)強(qiáng)度、變形、穩(wěn)定性、多物理場(chǎng)、流體、爆炸模擬仿真、碰撞模擬仿真等應(yīng)用,出現(xiàn)了一批商業(yè)化的工程軟件。
現(xiàn)代軟件是集功能完整性、技術(shù)先進(jìn)性與易學(xué)易用性于一體的高端通用機(jī)械分析軟件,以結(jié)構(gòu)力學(xué)分析為主,涵蓋線性、非線性、靜力、動(dòng)力、疲勞、斷裂、復(fù)合材料、優(yōu)化設(shè)計(jì)、概率設(shè)計(jì)、熱及熱結(jié)構(gòu)耦合、壓電等機(jī)械分析中幾乎所有的功能。在特種設(shè)備的強(qiáng)度分析方面應(yīng)用廣泛,其中的電磁和聲學(xué)計(jì)算功能可用于特種設(shè)備的無(wú)損檢測(cè)方法仿真研究。
(4) 多物理場(chǎng)耦合分析
現(xiàn)代壓力容器需要精確地解決流體和固體之間的相互作用問(wèn)題,同時(shí)熱分析和沖擊分析也是不可缺少的技術(shù)手段。所以也要解決如下問(wèn)題:
l 流固耦合問(wèn)題:大型容器、移動(dòng)容器、管道內(nèi)流動(dòng)
l 多相流問(wèn)題:鍋爐燃燒、流化床燃燒和反應(yīng)
l 傳熱和傳質(zhì)問(wèn)題:板式換熱器、塔板效率、分配器效率
l 沖擊載荷:水錘現(xiàn)象、撞擊
(5) 變?cè)O(shè)計(jì)安全系數(shù)的方法
為了增加本國(guó)產(chǎn)品的競(jìng)爭(zhēng)性,降低安全系數(shù)是目前世界各國(guó)和地區(qū)壓力容器標(biāo)準(zhǔn)的普遍傾向,美國(guó)( ASME )和歐洲統(tǒng)一壓力容器標(biāo)準(zhǔn)(正在制訂中)均降低了相應(yīng)的安全系數(shù),美國(guó)ASME VIII-1 2007將 n b 由 4.0 降為 3.5 ,ASME VIII-2 2007 n b 由 3.0 降為 2.4[4],歐洲統(tǒng)一壓力容器標(biāo)準(zhǔn)的 n b 最小值為 1.875 。我國(guó)新版容規(guī)將常規(guī)設(shè)計(jì)的安全系數(shù)由3.0降為2.7[5],按分析設(shè)計(jì)方法設(shè)計(jì)的安全系數(shù) n b 由2.6降為 2.4 ,相應(yīng)的技術(shù)標(biāo)準(zhǔn)GB150和JB4732也將做出調(diào)整。傳統(tǒng)的降低安全系數(shù)的前提條件是:
l 結(jié)構(gòu)分析設(shè)計(jì)水平的提高;
l 制造經(jīng)驗(yàn)的積累和制造技術(shù)水平的提高;
l 更嚴(yán)格的材料技術(shù)要求;
l 更科學(xué)的質(zhì)量保證體系。
在設(shè)計(jì)技術(shù)和制造水平協(xié)調(diào)一致的今天,研究成果已經(jīng)證實(shí),安全系數(shù)的降低并不直接影響安全性。標(biāo)準(zhǔn)應(yīng)該根據(jù)實(shí)際工況和設(shè)計(jì)條件的差異、設(shè)計(jì)計(jì)算的精確程度、材料、計(jì)算方法、制造質(zhì)量、檢驗(yàn)的綜合可靠性,考慮風(fēng)險(xiǎn)工程的能量、后果、人的因素,確定相應(yīng)的設(shè)計(jì)裕量。
(6) 安全理念所導(dǎo)致的結(jié)構(gòu)變化
現(xiàn)代壓力容器的設(shè)計(jì)不僅要考慮安全和滿足工藝要求,還要考慮環(huán)保和節(jié)約資源的要求。
l 突破傳統(tǒng)的埋地壓力容器:設(shè)計(jì)壓力低、消防間距小、失效模式主要要考慮土壤腐蝕;
l 體現(xiàn)環(huán)保要求的雙層埋地容器,可以實(shí)現(xiàn)遠(yuǎn)距離實(shí)時(shí)監(jiān)測(cè);
l 由于高參數(shù)所研發(fā)的容器:復(fù)合材料、纏繞容器
三、國(guó)際壓力容器標(biāo)準(zhǔn)技術(shù)發(fā)展趨勢(shì)
國(guó)際壓力容器標(biāo)準(zhǔn)技術(shù)的發(fā)展方向有以下特點(diǎn):
l 趨同性:信息技術(shù)的高速發(fā)展,使世界范圍內(nèi)的先進(jìn)技術(shù)迅速普及,圍繞壓力容器技術(shù)發(fā)展的技術(shù)標(biāo)準(zhǔn)也必然為技術(shù)的使用者所接受,因此世界范圍內(nèi)的壓力容器技術(shù)要求正在向統(tǒng)一的方向發(fā)展。特別在設(shè)計(jì)方法、焊接和無(wú)損檢測(cè)等技術(shù)領(lǐng)域,統(tǒng)一要求的趨向明顯。國(guó)際標(biāo)準(zhǔn)化組織正在深冷容器和移動(dòng)容器以及承壓設(shè)備材料等方面開(kāi)展工作,區(qū)域性的標(biāo)準(zhǔn)互認(rèn)已經(jīng)開(kāi)始。
l 區(qū)域性:由于歷史的原因和貿(mào)易區(qū)域的原因,目前已經(jīng)形成了以北美國(guó)家、以日本為代表的亞洲國(guó)家所形成的ASME體系和歐洲的PED及其協(xié)調(diào)標(biāo)準(zhǔn)體系的區(qū)域性格局。兩個(gè)體系的競(jìng)爭(zhēng)日益激烈,目的在于占領(lǐng)國(guó)際市場(chǎng)份額。
l 相容性:盡管世界上的各國(guó)的技術(shù)標(biāo)準(zhǔn)的技術(shù)內(nèi)容和具體技術(shù)指標(biāo)不完全相同,但各國(guó)都把自己的標(biāo)準(zhǔn)與其它國(guó)家標(biāo)準(zhǔn)相容作為目標(biāo),以實(shí)現(xiàn)標(biāo)準(zhǔn)的互相認(rèn)可和促進(jìn)貿(mào)易的發(fā)展。ASME在1999年進(jìn)行一個(gè)研究項(xiàng)目,對(duì)PED進(jìn)行徹底分析,并將PED的ESR與VIII-1對(duì)設(shè)計(jì)、建造和行政管理的要求進(jìn)行系統(tǒng)的比較,證明ASME標(biāo)準(zhǔn)增加一些內(nèi)容以后就可以滿足PED的要求。法國(guó)和美國(guó)也在開(kāi)展采用本國(guó)的壓力容器標(biāo)準(zhǔn)來(lái)滿足中國(guó)安全基本要求的研究工作。
l 貿(mào)易性:標(biāo)準(zhǔn)是國(guó)際貿(mào)易規(guī)