汽車車門防撞梁結(jié)構(gòu)的分析與優(yōu)化
汽車車門防撞梁結(jié)構(gòu)的分析與優(yōu)化,汽車,車門,防撞梁,結(jié)構(gòu),分析,優(yōu)化
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譯文題目：Development of natural gas vehicles
天然氣汽車的發(fā)展
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Development of natural gas vehicles
Abstract
This paper describes the development of compressed natural gas vehicles (CNG) on environmental protection of low-pollution, security, economic and CNG cars and filling stations and prospects for the development of countermeasures.
Key words: compressed natural gas vehicles; stations; development prospects;
Countermeasures
At present, China's major cities is a urban vehicle emissions a major source of air pollution, therefore, the development of clean energy vehicles have become the choice of the delay. Compressed natural gas vehicles (CNG) in their low energy consumption and emissions by all countries small and welcoming, is recognized internationally as the best alternative energy vehicle. The development of natural gas vehicle to address the environmental issues and energy issues are of great significance.
First, the development of natural gas vehicle
1. Development of foreign natural gas vehicle
Reduce pollution to protect the environment. many countries have issued a series of government regulations and the introduction of a number of incentive policies to promote the development of gas vehicle, such as the development of more stringent vehicle
Emission standards, in the natural gas supply, car purchase taxes and fees, equipment supply, gas station construction grant funds, tax incentives.
In 1992 the U.S. federal government enacted the "Energy Policy Act," or modified for the purchase of alternative fuel vehicles and the construction of stations in detail the provisions of the tax relief, but also enacted a tax cut that the use of natural gas and natural gas companies exempt from motor vehicle fuel sales tax.
There are more than 40 states in accordance with the policy of the federal government, law, drawn up on the mandatory state and encourage the use of clean fuel CNG vehicles, such as policies and measures to promote the CNG filling station development and construction of motor vehicles. At present, more than 40 countries around the world have a gas car, mainly in the rich natural gas resources in Italy, New Zealand, Argentina, Brazil and other countries and stricter environmental regulations the United States, Japan and other countries. 2, China's Natural Gas Vehicle Development
80 In the mid-20th century, the introduction of some of our CNG filling station equipment set up in Sichuan's first CNG filling stations in China; in 1993 the China national Petroleum Corporation on the introduction of foreign technology systems in 1996 installations and will be filling stations modified car parts made of the introduction of technology, standardization of technical standards. 1999 National Clean Automobile Action Coordination Leading Group was established to start the Beijing, Tianjin, Shanghai, Xi'an, Shenzhen and other cities in 12 pilot areas to promote the application of clean energy in the popularization and application of CNG vehicles and filling stations has made unprecedented building results. According to relevant statistics, as of 2004 there were some areas of China's natural gas vehicle more than 20 million vehicles, more than 700 filling stations Block.
Second, natural gas vehicle (CNG) fuel and other environmental and economic benefits compared
Compressed natural gas vehicles:
20MPa compressed natural gas in the car to compressed natural gas cylinders in use by the supply of internal combustion engine after the pressure reducer.
To CNG fuel for vehicles compared with gasoline has the following advantages:
1 Reduce pollution and improve the atmospheric environment: natural gas is a clean energy, with a high calorific value, high efficiency, pollution, etc., the comparison is totally burned, not carbon deposition, CO, NOX and particulate emissions than gasoline,
Significantly reduced exhaust pollution. Motor vehicle exhaust is the major source of urban air pollution, one of which is carbon monoxide harmful ingredients (C0), hydrocarbons (HC), nitric oxide (N0) and nitrogen dioxide (NO2) and so on. According to the data, the use of gas as a motor fuel and gasoline as fuel can reduce emissions compared to 90% CO, 90% S02, 72% HC, 39% NOX, 24% CO2, non-dust emissions, to improve the urban environment has a significant role in. A typical diesel engine and gasoline engine emissions and gas machine is shown in table l.
2 CNG vehicles for a higher security
Compared with gasoline, compressed natural gas is a relatively safe fuel. (1) Natural gas explosion limit is 5% higher than gasoline (lower explosion limit for the one percent of hundred) high, methane ignition for 645 ℃, ignition than gasoline high 218 ℃, compared to not ignite. Low density of methane, the relative density of about 0.55, resulting in leakage of gas will soon be distributed in the air, in the case of the natural environment it is difficult to form a hot combustion conditions, once the compressed natural gas from the tank or pipe leaks, leak immediately surrounding the formation of low-temperature zone, so that the difficulties of natural gas combustion. Therefore is a fairly safe CNG motor fuel. Natural gas and fuel properties of gasoline are shown in table.
Department of natural gas vehicle cylinder pressure vessel (20MPa), its materials and manufacture and testing in order that all States have strict control, in China there're "compressed natural gas cylinder vehicle standards)) (GBl7258-1998).
Cylinders fitted with explosion-proof facilities, pressure reducer, valves and other equipment, strict standards high, and gas supply system is safe and reliable and will not tip over due to vehicle collision or cause fire or explosion, and the petrol tank of motor vehicles department of non-pressure vessels, fire easily after the explosion.
3 Will help ease the contradiction between energy supply and demand tensions.
China's economy is in a stage of rapid development, the number of vehicles to 1 million / year above the rate of increase of a substantial increase in gasoline demand of resources, our need to import large quantities of crude oil per year, refined oil and LPG. Optimize the use of gas cars motor fuel supply structure has changed only motor fuel gasoline, diesel patterns, not only eased the problem of shortage of petrol and transport services to meet the needs of the development.
4 Extend engine live. The spread of natural gas to the gas entering the engine, the engine easily and uniformly mixed air, burning the comparison is totally clean; can improve the thermal cycle efficiency, speed up the burning speed, full use of combustion heat; CNG octane number at the same time high performance uprising, when agents do not need to add the uprising will not dilute the lubricating oil, making the parts inside the engine.
Cylinder greatly reduced wear and tear, so that the engine oil life and increase the use of the period. All of these vehicles will reduce maintenance and operating costs, thereby enhancing the economy of the use of vehicles.
5 Have a higher economic efficiency. At present, domestic gasoline prices continued to rise, the price system and the world has been the use of CNG vehicle will be able to save nearly 40% of fuel costs, as shown in table 3.
Third, CNG vehicle development prospects
CNG cars and filling stations will have broad prospects for development, mainly in the following aspects:
1 Cars of the rapid growth of oil resources and environmental protection, the grim situation, the decision of the development of natural gas vehicles as a solution to energy issues and environmental issues an important way.
2 “Eleventh Five-Year" period, a new type of clean energy vehicles has been included in "long-term national science and technology development planning", the state will continue to organize and implement a variety of clean energy vehicles of major scientific and technological projects, the focus of support, including natural gas vehicles, including vehicles, parts, etc., will further promote the development of natural gas vehicle.
3 Large-scale developments of China's natural gas resources and pipeline construction to accelerate the pace of development of CNG and LPG filling stations make it possible. According to China's natural gas use planning, for nearly a decade, "West-East Gas Transmission", "second Shaanxi-Beijing", such as a large number of gas pipeline and gas pipeline along the cities has built large-scale use of natural gas in China's gradual improvement of infrastructure; natural gas filling stations will gradually form a network. 4, the development of CNG auto gas source with the stability of assurance to Tianjin as an example, at present, Tianjin has established a perfect system of natural gas transmission and distribution, from northern Shaanxi, Tianjin, North China Oil Field to supply, gas supply is nearly mid-2005 600 million m3, 2006 was projected to reach 800 million m3, the length of pipe network 6894km, of which high-pressure pipeline 591km, for the "Eleventh Five-Year" period of Tianjin to develop large-scale construction of CNG filling stations car provides a guarantee.
Fourth, CNG cars and filling stations to explore the development of countermeasures In order to speed up the use of natural gas as a clean fuel vehicle development, makes the following recommendations:
1 The Government has introduced policies to encourage and support: the development of all countries in the world experience shows that government support is a necessary condition for accelerated development, the impact of its economic policy is an important factor in their development should be guaranteed in law, in the gas automobile production, modification, parts and components production, station construction, vehicle purchase and use of gas, maintenance and other aspects of pricing, taxation, investment, subsidies and other aspects of the preferential policies supporting. Gas prices affect gas vehicle development is an important factor, only the gas prices and gasoline prices when the difference is large enough to form, gas car before the development of an economic foundation and driving force.
2 Strengthen leader ship, the implementation of unified management .The development of CNG vehicles the construction of high-quality, convenient filling stations, the need for planning, public security, fire safety, labor, technical support supervisor and other departments.
3 In the municipal plan, filling stations and gas stations should be considered co-ordination, rational distribution and coordinated development. To make full use of
Existing land resources and in ensuring the environmental safety of oil and gas under the premise of building one station.
4 Followed by motor cars and CNG filling stations in the simultaneous development of the principles, only in the stations into a network under the conditions, CNG vehicle can really develop. At the same timescale of only CNG car to a certain number, the normal operation of filling stations in order to achieve profitability.
5 The strict legal system: the development of stringent vehicle emissions regulations, and make sure that standards are not road vehicles are determined not to be on the qualifications of CNG vehicle Modify-Factory critical examination, certification. First of all, the city should the city bus, taxi, as the focus of the development of CNG vehicle, bus stop some of the phenomenon of black smoke pollution of the environment.
6 Step up publicity. At present, natural gas car is still at the initial stage, the public nature of its environmental protection, safety, economy, reliability, do not fully understand, so, it is necessary to carry out a wide range of social advocacy, efforts to increase awareness of the dangers of automobile exhaust, to make people aware of CNG is a clean, safe and economical fuel, so that the development of natural gas vehicles have been recognized by all sectors of society and support.
Compressed natural gas vehicles because of its remarkable economic and social benefits the development of the natural gas market will become a new field of applications. More and more importance in the environmental protection situation, along with natural gas resources in the area of the development and application of the widening, which will reduce the environmental pressure, is to ease the oil shortage and achieve sustainable development of a reliable guarantee.
天然氣汽車的發(fā)展
摘 要
本文闡述了發(fā)展壓縮天然氣汽車(CNG)的環(huán)保低污染性、安全性、經(jīng)濟(jì)性及CNG汽車和加氣站的發(fā)展前景及對(duì)策。
關(guān)鍵詞：壓縮天然氣汽車；加氣站；發(fā)展前景；對(duì)策
目前，我國(guó)一些大城市的汽車尾氣排放是城市大氣污染的主要源頭，因此，發(fā)展清潔能源汽車已成為刻不容緩的的選擇。壓縮天然氣汽車(CNG)以其能耗低、污染物排放量小而受到各國(guó)的歡迎，是國(guó)際公認(rèn)的最理想的車用替代能源。發(fā)展天然氣汽車對(duì)于解決環(huán)境問題和能源問題都具有重要意義。
一、天然氣汽車的發(fā)展情況
l、國(guó)外天然氣汽車發(fā)展概況
為保護(hù)環(huán)境減少污染，許多國(guó)家政府頒布了一系列法規(guī)及出臺(tái)一些鼓勵(lì)性政策，促進(jìn)燃?xì)馄嚢l(fā)展，如制定更嚴(yán)格的汽車尾氣排放標(biāo)準(zhǔn)，在天然氣供應(yīng)、汽車購(gòu)置稅費(fèi)，設(shè)備供給、加氣站建設(shè)等方面給予資金、稅收優(yōu)惠政策。
美國(guó)聯(lián)邦政府1992年頒布的《能源政策法》，對(duì)于購(gòu)買或改裝代用燃料汽車及加氣站的建設(shè)減免稅作出詳細(xì)規(guī)定，同時(shí)還頒布了使用天然氣的減稅政策，并免征天然氣公司的汽車燃料銷售稅。有40多個(gè)州根據(jù)聯(lián)邦政府的政策、法律，制定了本州有關(guān)強(qiáng)制和鼓勵(lì)使用CNG等清潔燃料汽車的政策和措施，推動(dòng)了CNG汽車發(fā)展和加氣站建設(shè)。目前，全世界已有40多個(gè)國(guó)家擁有燃?xì)馄?，主要分布在天然氣資源豐富的意大利、新西蘭、阿根廷、巴西等國(guó)家和環(huán)保法規(guī)嚴(yán)格的美國(guó)、日本等國(guó)。
2、我國(guó)天然氣汽車發(fā)展概況
20世紀(jì)80年代中期，我國(guó)引進(jìn)了部分CNG加氣站設(shè)備，在四川建立了我國(guó)第一個(gè)CNG加氣站；1993年中國(guó)石油天然氣總公司系統(tǒng)引進(jìn)國(guó)外有關(guān)技術(shù)并于 1996年將加氣站裝置和汽車改裝部件引進(jìn)技術(shù)國(guó)產(chǎn)化、技術(shù)標(biāo)準(zhǔn)規(guī)范化。1999年全國(guó)清潔汽車行動(dòng)協(xié)調(diào)領(lǐng)導(dǎo)小組成立，啟動(dòng)了北京、天津、上海、西安、深圳等12個(gè)試點(diǎn)城市地區(qū)的清潔能源推廣應(yīng)用工作，在CNG汽車的推廣應(yīng)用和加氣站建設(shè)方面取得了前所未有的成效。根據(jù)有關(guān)部門統(tǒng)計(jì)數(shù)字，截止到2004年我國(guó)一些地區(qū)共有天然氣汽車20多萬(wàn)輛，加氣站700多座。
二、天然氣汽車(CNG)與其它燃料的環(huán)境、經(jīng)濟(jì)效益比較
壓縮天然氣汽車：
天然氣壓縮至20MPa于汽車用壓縮天然氣鋼瓶中，經(jīng)減壓器后供給內(nèi)燃機(jī)。
以CNG作汽車燃料與汽油相比具有以下優(yōu)點(diǎn)：
l、降低污染，改善大氣環(huán)境：天然氣是一種清潔能源，具有熱值高、效率高、污染小等特點(diǎn)，燃燒比較完全，不易積碳，CO、NOx和微粒的排放量均低于汽油，排氣污染明顯降低。機(jī)動(dòng)車尾氣是城市大氣污染主要來源之一，其中主要有害成分是一氧化碳(C0)、碳?xì)浠衔?HC)、一氧化氮(N0)和二氧化氮 (NO2)等。據(jù)有關(guān)資料顯示，使用天然氣作為汽車燃料與汽油作燃料相比可以減少排放90％CO、90％S02、72％HC、39％NOx、 24％CO2、無粉塵排放，對(duì)改善城市環(huán)境有顯著作用。典型的柴油機(jī)與汽油機(jī)及天然氣機(jī)排放情況比較見表l。
2、CNG汽車有較高的安全性
與汽油相比，壓縮天然氣是相對(duì)安全的燃料。
(1) 天然氣爆炸下限為5％，比汽油(爆炸下限為l％)高，甲烷燃點(diǎn)為645℃ ，比汽油燃點(diǎn)高218℃，相比不易點(diǎn)燃。甲烷密度低，相對(duì)密度為0．55左右，泄漏的氣體很快會(huì)在空氣中散發(fā)，在自然環(huán)境中難以形成遇火爆燃的條件，一旦壓縮天然氣從儲(chǔ)罐或管路中泄漏，泄漏點(diǎn)周圍會(huì)立即形成低溫區(qū)，使天然氣燃燒困難。因此CNG是一種相當(dāng)安全的汽車燃料。天然氣與汽油的燃料特性比較見表2
(2)天然氣汽車的鋼瓶系高壓容器
(20MPa)，其材質(zhì)及制造、檢驗(yàn)試驗(yàn)在各國(guó)均有嚴(yán)格的規(guī)程控制，在我國(guó)有《汽車用壓縮天然氣鋼瓶標(biāo)準(zhǔn)))(GBl7258—1998)。
鋼瓶安裝有防爆設(shè)施，減壓器、閥門等設(shè)備，嚴(yán)密度標(biāo)準(zhǔn)高，供氣系統(tǒng)安全可靠，不會(huì)因汽車碰撞或翻覆造成失火或爆炸，而汽油汽車的油箱系非壓力容器，著火后容易爆炸。
3、有利于緩解能源緊張的供需矛盾。
我國(guó)經(jīng)濟(jì)正處于高速發(fā)展階段，汽車數(shù)量以100萬(wàn)輛／年以上的速度遞增，對(duì)汽油資源需求大量增加，我國(guó)每年需要進(jìn)口大量原油、成品油和LPG。使用燃?xì)馄嚳蓛?yōu)化
汽車燃料供應(yīng)結(jié)構(gòu)，改變了汽車燃料只有汽油、柴油的格局，既緩解了汽油供應(yīng)緊張的問題又滿足交通事業(yè)發(fā)展的需要。
4、可延長(zhǎng)發(fā)動(dòng)機(jī)壽命。天然氣容易擴(kuò)散，以氣態(tài)進(jìn)入發(fā)動(dòng)機(jī)，在發(fā)動(dòng)機(jī)中容易和空氣均勻混合，燃燒比較完全、干凈；可以提高熱循環(huán)效率，加快燃燒速度，充分利用燃燒熱能；同時(shí)CNG辛烷值高，抗暴性能好，使用時(shí)不需要添加抗暴劑，不會(huì)稀釋潤(rùn)滑油，因而使發(fā)動(dòng)機(jī)氣缸內(nèi)的零件磨損大大減少，使發(fā)動(dòng)機(jī)的壽命和潤(rùn)滑油的使用期限大幅度增長(zhǎng)。所有這些都會(huì)降低汽車的保養(yǎng)和運(yùn)行費(fèi)用，從而提高汽車使用的經(jīng)濟(jì)性。
5、有較高的經(jīng)濟(jì)效益。目前，國(guó)內(nèi)汽油價(jià)格持續(xù)上升，價(jià)格體系已和世界接軌，使用CNG汽車將能節(jié)省近40％燃料費(fèi)用，見表3。
三、CNG汽車的發(fā)展前景
CNG汽車和加氣站具有廣闊的發(fā)展前景，主要表現(xiàn)在以下幾方面：
l、汽車保有量的飛速增長(zhǎng)、石油資源和環(huán)保的嚴(yán)峻形勢(shì)，決定了發(fā)展天然氣汽車成為解決能源問題和環(huán)境問題的重要途徑。
2、“十一五”期間，新型清潔能源汽車已被列入《國(guó)家科技發(fā)展中長(zhǎng)期規(guī)劃》，國(guó)家將繼續(xù)組織實(shí)施涉及各種清潔能源汽車的重大科技項(xiàng)目，重點(diǎn)支持包括天然氣汽車在內(nèi)的整車、零部件等關(guān)鍵技術(shù)，將進(jìn)一步促進(jìn)天然氣汽車的發(fā)展。
3、我國(guó)天然氣資源大規(guī)模開發(fā)及管道建設(shè)步伐加快使發(fā)展CNG和加氣站成為可能。根據(jù)我國(guó)天然氣利用規(guī)劃，近十年“西氣東輸”、“陜京二線”等一大批輸氣管道及沿線城市燃?xì)夤艿老嗬^建成，我國(guó)大規(guī)模利用天然氣的基礎(chǔ)設(shè)施逐步完善，天然氣加氣站也將逐步形成網(wǎng)絡(luò)。
4、發(fā)展CNG汽車具有穩(wěn)定的氣源保證，以天津?yàn)槔?，目前天津市已建立了完善的天然氣輸配系統(tǒng)，由陜北、大港、華北等油田向天津供氣，2005年年供氣量近6 億m3，2006年預(yù)計(jì)達(dá)8億m3，管網(wǎng)長(zhǎng)度6894km，其中，高壓管線591km，為“十一五”期間天津市大力發(fā)展CNG汽車大規(guī)模建設(shè)加氣站提供了保證。
四、CNG汽車和加氣站發(fā)展對(duì)策探討
為加快以天然氣為燃料的清潔汽車的發(fā)展，提出以下建議：
1、政府出臺(tái)鼓勵(lì)和扶持政策：世界各國(guó)發(fā)展經(jīng)驗(yàn)表明，政府的支持是加快發(fā)展的必要條件，其經(jīng)濟(jì)政策是影響其發(fā)展的重要因素，應(yīng)在法律方面予以保障，在燃?xì)馄嚿a(chǎn)、改裝、零部件生產(chǎn)，加氣站建設(shè)，燃?xì)馄囐?gòu)買和使用、維修等環(huán)節(jié)制定價(jià)格、稅收、投資、補(bǔ)貼等方面配套的優(yōu)惠政策。燃?xì)鈨r(jià)格是影響燃?xì)馄嚢l(fā)展的重要因素，只有燃?xì)鈨r(jià)格與汽油價(jià)格形成足夠大差價(jià)時(shí)，燃?xì)馄嚨陌l(fā)展才具有經(jīng)濟(jì)基礎(chǔ)和推動(dòng)力。
2、加強(qiáng)領(lǐng)導(dǎo)，實(shí)行統(tǒng)一管理。發(fā)展CNG汽車必須建設(shè)優(yōu)質(zhì)、便利的加氣站，需要規(guī)劃、公安、消防、勞動(dòng)、技監(jiān)等部門的支持。
3、在市政規(guī)劃中，加氣站與加油站應(yīng)統(tǒng)籌考慮，合理布局，協(xié)調(diào)發(fā)展。盡量利用現(xiàn)有土地資源，在確保環(huán)境安全的前提下建設(shè)油氣合一站。
4、遵循CNG汽車與加氣站同步發(fā)展的原則，只有在加氣站成網(wǎng)的條件下，CNG汽車才能真正發(fā)展。同時(shí)也只有CNG汽車規(guī)模到了一定數(shù)量，加氣站才能正常運(yùn)轉(zhuǎn)，實(shí)現(xiàn)盈利。
5、嚴(yán)格法律制度：制定嚴(yán)格的汽車尾氣排放法規(guī)，切實(shí)做到不達(dá)標(biāo)車輛堅(jiān)決不予以上路，對(duì)CNG汽車改裝廠的資格進(jìn)行嚴(yán)格審查，認(rèn)證。首先應(yīng)將城市城市公交車、出租汽車作為CNG汽車發(fā)展的重點(diǎn)，杜絕部分公交車冒黑煙污染環(huán)境的現(xiàn)象。
6、加大宣傳力度。目前，天然氣汽車尚處于起步階段，社會(huì)公眾對(duì)它的環(huán)保性，安全性，經(jīng)濟(jì)性，可靠性還不充分了解，所以，要進(jìn)行廣泛的社會(huì)宣傳，努力提高人們對(duì)汽車尾氣危害性的認(rèn)識(shí)，使人們了解CNG是清潔、安全、經(jīng)濟(jì)的車用燃料，使發(fā)展天然氣汽車得到社會(huì)各方面的認(rèn)可和支持。
壓縮天然氣汽車由于其顯著的經(jīng)濟(jì)效益和社會(huì)效益將成為天然氣市場(chǎng)開發(fā)應(yīng)用的一個(gè)新領(lǐng)域。在環(huán)境保護(hù)越來越受到重視的形勢(shì)下，隨著天然氣資源的開發(fā)和應(yīng)用領(lǐng)域的拓寬，此舉將是減輕環(huán)境污染壓力、緩解石油緊缺，實(shí)現(xiàn)可持續(xù)發(fā)展的可靠保證。
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