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設(shè)計(jì)(論文)題目:某轎車膜片彈簧式離合器的結(jié)構(gòu)設(shè)計(jì)與分析
學(xué)生姓名:
任務(wù)書填寫要求
1.畢業(yè)設(shè)計(jì)(論文)任務(wù)書由指導(dǎo)教師根據(jù)各課題的具體情況填寫,經(jīng)學(xué)生所在專業(yè)的負(fù)責(zé)人審查、系
(院)領(lǐng)導(dǎo)簽字后生效。此任務(wù)書應(yīng)在畢業(yè)設(shè)計(jì)(論文)開始前一周內(nèi)填好并發(fā)給學(xué)生。
2.任務(wù)書內(nèi)容必須用黑墨水筆工整書寫,不得涂改或潦草書寫;或者按教務(wù)處統(tǒng)一設(shè)計(jì)的電子文檔標(biāo)準(zhǔn)格式
(可從教務(wù)處網(wǎng)頁上下載)打印,要求正文小4號(hào)宋體,1.5倍 , 打印在 上 。
3.任務(wù)書內(nèi)填寫的內(nèi)容,必須 學(xué)生畢業(yè)設(shè)計(jì)(論文) 的情況 一 , ,應(yīng) 經(jīng) 所在專業(yè)
系(院) 領(lǐng)導(dǎo)審 后 可 填寫。
4.任務(wù)書內(nèi) 學(xué)院 、 專業(yè) 名 的填寫,應(yīng)寫 文? ,不¢寫£字?¥。學(xué)生的 學(xué)號(hào) 要寫
?號(hào),不¢?寫§后2currency1或1currency1£字。
5.任務(wù)書內(nèi) 要'“文? 的填寫,應(yīng)按??fifl –學(xué)院? 畢業(yè)設(shè)計(jì)(論文)?寫· ?的要求書寫。
6. ??? ?”的填寫,應(yīng) 按??標(biāo)GB/T 7408—94?£據(jù)… ‰ 格式、? ‰ 、?” `′
??ˉ?·?的要求,一˙用¨ ?£字書寫。? 2002?4?2? 或 2002-04-02”。
畢 業(yè) 設(shè) 計(jì)(論 文)任 務(wù) 書
1.?畢業(yè)設(shè)計(jì)(論文)課題應(yīng) ?的目的:
1. ?查ˇ—、 文? 與 的¢ 。
2. 合 用專業(yè) 論、 分析 題的¢ 。
3. 設(shè)計(jì)或? a的 ?¢ 。
4. 設(shè)計(jì)、計(jì) 與 的¢ ,???用計(jì) o的¢ 。
2.?畢業(yè)設(shè)計(jì)(論文)課題任務(wù)的內(nèi)容 要求(?? 始£據(jù)、– 要求、工 要求 ):
1. ?設(shè)計(jì)要求 車離合器的結(jié)構(gòu)?式 合 ,? 離合器的 ?結(jié)構(gòu) ? '£的 計(jì) ;
§后 離合器 要???的結(jié)構(gòu) ? 設(shè)計(jì)計(jì) ,要求?? 的設(shè)計(jì) , '£ 驟;
2. o構(gòu)或者結(jié)構(gòu)設(shè)計(jì)要 展?,分析結(jié)果要 說明;
3. 一篇符合fifl –學(xué)院畢業(yè)論文· 的系統(tǒng)– 文檔,??各類– 資料, ;
4. ¢夠 各項(xiàng)任務(wù),'加§后的畢業(yè)設(shè)計(jì)答辯。
畢 業(yè) 設(shè) 計(jì)(論 文)任 務(wù) 書
3. ?畢業(yè)設(shè)計(jì)(論文)課題 果的要求〔?? ?、 物 硬?要求〕:
1.按” 一篇符合fifl –學(xué)院論文· 的畢業(yè)設(shè)計(jì)說明書(畢業(yè)論文),¢ 說明設(shè)計(jì) 驟 思路;
2.¢ 結(jié)構(gòu) 整,合 可靠的– a;
3.¢ 應(yīng)的?? 仿真結(jié)果說明;
4. 應(yīng)的 – '£說明。
4. 要'“文?:
[1] 周海濤,商佳園.淺談 車離合器的發(fā)展[J].企業(yè)導(dǎo)報(bào),2014.7.
[2] 胡靜.捷 轎車離合器膜片彈簧的設(shè)計(jì)與ˇ—[D].長(zhǎng)春 工大學(xué),2008.
[3] 許兆棠,劉永臣. 車構(gòu)造(下)[M].北京:?防工業(yè)出版社,2012.
[4] 陳立德.o械設(shè)計(jì) 礎(chǔ)[M].北京:高 教育出版社,2013.
[5] 馬小峰.離合器 ?校核與應(yīng)用[J].現(xiàn)?車用動(dòng) ,2012,3.
[6] 徐石安,江發(fā)潮. 車離合器[M].北京:清華大學(xué)出版社,2005.
[7] 王望予. 車設(shè)計(jì)[M].北京:o械工業(yè)出版社,2006.
[8] 林世裕.膜片彈簧離合器的演 、結(jié)構(gòu)形式與[J].江蘇工學(xué)院學(xué)報(bào),1990,11(1):7-18
[9] 朱茂桃,劉雪萊. 車離合器膜片彈簧的優(yōu)化設(shè)計(jì)分析[J].o械設(shè)計(jì)與 造,2014,6.
[10] 張文華.膜片彈簧式離合器的分析 優(yōu)化設(shè)計(jì)[J].應(yīng)用¢源– ,2009,12.
[11] 嚴(yán)紅.淺談 車膜片彈簧離合器[J].洛陽 工學(xué)院學(xué)報(bào),2012,22(2).
[12] 肖文穎,許海華. 車離合器膜片彈簧的優(yōu)化設(shè)計(jì)[J].公路與 ,2007.121(4):9-10
[13] 韋遠(yuǎn)飛,朱啟庚.介紹幾種自?試膜片彈簧離合器
[14] 余志生. 車 論[M].北京:o械工業(yè)出版社,2000.
[15] 林世裕.膜片彈簧與蝶形彈簧離合器的設(shè)計(jì)與 造[M].南京:東南大學(xué)出版社,1995.
畢 業(yè) 設(shè) 計(jì)(論 文)任 務(wù) 書
5.?畢業(yè)設(shè)計(jì)(論文)課題工 度計(jì)劃:
2015.12.05-2015.12.22確? 題,填寫審題?;指導(dǎo)教師下發(fā)任務(wù)書,學(xué)生查 課題 '“文?、資
料,?寫開題報(bào)告。
2015.12.23-2016.01.22提‰開題報(bào)告、 文'“資料 譯文、畢業(yè)設(shè)計(jì)(論文)大綱;開始畢業(yè)設(shè)計(jì)
(論文)。
2016.01.23-2016.04.15具體設(shè)計(jì)或ˇ— a 施,提‰畢業(yè)設(shè)計(jì)(論文)草稿,填寫 ” 查?。
2016.04.16-2016.05.04 論文或設(shè)計(jì)說明書、 材料,提‰畢業(yè)設(shè)計(jì)(論文)?稿,指導(dǎo)老師審
核。
2016.05.05-2016.05.09提‰畢業(yè)設(shè)計(jì) 質(zhì)文檔,學(xué)生準(zhǔn)備答辯;評(píng) 教師評(píng) 學(xué)生畢業(yè)設(shè)計(jì)(論文)。
2015.05.10-2015.05.16根據(jù)學(xué)院統(tǒng)一安 , 畢業(yè)設(shè)計(jì)(論文)答辯。
所在專業(yè)審查 :
負(fù)責(zé)人: 2016 ? 1 ? 11 ?
畢 業(yè) 設(shè) 計(jì)(論 文)開 題 報(bào) 告
設(shè)計(jì)(論文)題目:某轎車膜片彈簧式離合器的結(jié)構(gòu)設(shè)計(jì)與分析
學(xué)生姓名:
開題報(bào)告填寫要求
1.開題報(bào)告(含“文獻(xiàn)綜述”)作為畢業(yè)設(shè)計(jì)(論文)答辯委員會(huì)對(duì)學(xué)生答辯資格審查的依據(jù)材料之一。此
報(bào)告應(yīng)在指導(dǎo)教師指導(dǎo)下,由學(xué)生在畢業(yè)設(shè)計(jì)(論文)工作前期內(nèi)完成,經(jīng)指導(dǎo)教師簽署意見及所在專業(yè)審查
后生效;
2.開題報(bào)告內(nèi)容必須用黑墨水筆工整書寫或按教務(wù)處統(tǒng)一設(shè)計(jì)的電子文檔標(biāo)準(zhǔn)格式打印,禁止打印在其它紙
上后剪貼,完成后應(yīng)及時(shí)交給指導(dǎo)教師簽署意見;
3.“文獻(xiàn)綜述”應(yīng)按論文的框 成文, 書寫(或打?。┰?開題報(bào)告 一 目?jī)?nèi),學(xué)生寫文獻(xiàn)綜述的
文獻(xiàn)應(yīng) 15 ( );
4. 期的填寫,應(yīng) 按 標(biāo)GB/T 7408—94 據(jù) 交?格式 ¢£交? 期 時(shí)?¥
?§currency1'“的要求,一?用??fi fl書寫。 “2004 4 26 ”或“2004-04-26”。
5 開題報(bào)告(文獻(xiàn)綜述)fl–?按?– · ?書寫,???1.5?。
畢 業(yè) 設(shè) 計(jì)(論文) 開 題 報(bào) 告
1.結(jié)合畢業(yè)設(shè)計(jì)(論文)”題?…,‰據(jù)所查 的文獻(xiàn)資料,? `寫 1000fl′?的文獻(xiàn)綜述:
一.前? ˉ題目的 意?: ˙ˉ¨”題為某轎車離合器的結(jié)構(gòu)設(shè)計(jì)與分析, ˙設(shè)計(jì)為膜片彈簧離合器的
設(shè)計(jì), 此設(shè)計(jì) ??的意? ?的用?,ˇ為離合器作為— 統(tǒng) 的?要 ,它
之?的 ?作用, 它的?要a 容· 。一 的離合器???o 車的 ,所 設(shè)計(jì)一
作? 分離 的離合器?分?要, ˉ¨ 設(shè)計(jì)離合器??? 對(duì) 車內(nèi)?要 的 ?。 ˉ題??:離
合器 車 統(tǒng)的 要 成之一,它 常安裝在 飛 后側(cè), 與 相連 的 。 過離合器
的結(jié)合或分離,使 與 統(tǒng) 驅(qū) 車 聯(lián) 或者斷開。離合器還 的作用 :保證 車平穩(wěn) 步 保
證 統(tǒng)?擋時(shí)工作平順 防止 統(tǒng)過載。離合器的種類 摩擦離合器 液力偶合器或液力變矩器 電
磁離合器。其工作原理 :離合器的 分 分借 觸面?的摩擦作用,或 用液–作為 介質(zhì)
(液力偶合器),或 用磁力 (電磁離合器)來 遞轉(zhuǎn)矩,使兩者之?可 暫時(shí)分離,又可逐漸 合,在
過程 又允許兩 分相互轉(zhuǎn) 。它的優(yōu)點(diǎn):目前, 車上 ?采用膜片彈簧作為壓緊彈簧的離合器,稱為
膜片彈簧離合器。它的特點(diǎn)在 ,膜片彈簧既 離合器的壓緊 構(gòu)又 分離杠桿。由 膜片彈簧離合器其結(jié)構(gòu)
原ˇ,它 下優(yōu)點(diǎn):(1)膜片彈簧的軸向尺寸較· 徑向尺寸很?,這 利 在?o離合器 遞轉(zhuǎn)矩?力
的?…下減·離合器的軸向尺寸(2)膜片彈簧的分離只 分離杠桿的作用, 需專門的分離杠桿,使離合
器結(jié)構(gòu)???化,零 目 ,質(zhì)量輕(3)由 膜片彈簧軸向尺寸·,所 可 適 增加壓 的厚度,?o
熱容量; 還可 在壓 上增設(shè)散熱筋及在離合器蓋上開設(shè)較?的 風(fēng)孔來改善散熱條 (4)膜片彈簧離
合器的 要 形狀?單,可 采用沖壓加工,?批量生產(chǎn)時(shí)可 降低生產(chǎn)成 二. 題 車作為現(xiàn)代交
工具之一,已成為 類現(xiàn)代文明生活 生產(chǎn) 可或缺的的?要 成 分。我 自 1953 創(chuàng)造 一 車制造
廠至今,已 140多家 車制造廠,還 更多的 車改裝廠。隨 我 民經(jīng)濟(jì)的 展 民生活水平
的 斷?o,對(duì) 車的使用功? 斷?出 的要求。為 車 種? 需求,在 車上需要一 的
統(tǒng)?,F(xiàn)代 車上 常用的 式 統(tǒng),它 由 及離合器 變 器 向 軸 減
器 器 驅(qū) 車 的 裝 ( 軸) 成。其 離合器 作為一 在的。它在
統(tǒng) 遞 矩 分離轉(zhuǎn) 減 過載保 多?作用。其 質(zhì) 車的a?,對(duì) 使用工…
載 ?的 車更 此。離合器的 展 :1889 , 明 車離合器,它 過
?來工作?!椤觌x合器 ?, 過分離?¥??§形currency1',“?彈簧, 使離合器分離。隨后出現(xiàn) 摩擦
片,其 展?經(jīng)? 一 fifl的過程, 使用–?作為§形 摩擦面的材料,?很 · ??代。? 后,
單 離合器又?” §形 離合器。De Dion Bouton 一 ?… 單 離合器 離合器‰來 展 向
的 。后來,隨 Ferodo? 摩擦片的出現(xiàn),離合器`′?? 一??步。? 摩擦片 1920 代 一
使用 代, 其·ˉ? 摩擦片?代。隨 轉(zhuǎn) 的 斷?o,離合器變??來??,˙此之¨,用
來作用 分離杠桿的分離軸 一 處 ?壓狀?下,使其 離合器¨ 很容? 生?ˇ,—其 在 o轉(zhuǎn)
時(shí)?擋。為 , 開 出 膜片彈簧離合器,膜片彈簧離合器 生 1936 用 車的
, 在1930 代后期在 ?批量生產(chǎn)。1960 代 至今,? 所 的 車制造 采用膜片彈簧離
合器。 內(nèi)¨ 展現(xiàn)狀:我 車業(yè)的o 展, 我 車離合器? 需求a ? 增fl。隨 我 自
擋轎車的增加,我 統(tǒng)離合器?業(yè)的前 ?, ?業(yè) 在?求 的a 展的?徑。隨 多種變 o`
′的 展 ?,我 離合器`′?由單一的 統(tǒng)的摩擦式離合器向多種 `′ 的 向 展。在
用車 , 內(nèi)`′ ¨`′ ??較明 。在 還在轎車 及 ?, ¨轎車已經(jīng)向 適 保 ?
向 展。今后離合器?業(yè) 展的一 向? ??o?擋的 適a, ¨ 種自 變 `′ 減 降?
的離合器`′應(yīng)用 生。 內(nèi) ?在`′上還 在工業(yè) 上 ?較 。在 用車離合器 面我 競(jìng)爭(zhēng)
優(yōu)勢(shì)的,很多¨資?業(yè) 無§?入我 載貨 車的配 統(tǒng)。為什么呢,難道 ¨沒 開 出適合載貨 車用
的離合器? 的, 要的 別 ?造成的。在 ,載貨 車 載已經(jīng)成為一 遍的現(xiàn)象,即“?噸
·標(biāo)”現(xiàn)象ˉ常突出,離合器? 這樣設(shè)計(jì)的。所 ?在? 上運(yùn)用自 。我 可 現(xiàn) 用離合器
在?,盡管 此,我 在離合器的 展上還 很fl的路要走, 適應(yīng) 的 展趨勢(shì)。 三.總結(jié)離合器
車 較為?要的一 分。 過上述? 面 ? ,我 離合器制造水平與 ¨還 較? ?,
這 一 擺在我 面前的 峻事 。這?需要我 仔細(xì)對(duì)他分析與 ,這? ?o我 自身?力的一種?徑。
. 文獻(xiàn) [1] 周海濤, 佳園.淺談 車離合器的 展[J].?業(yè)導(dǎo)報(bào),2014.7. [2] 胡靜.捷達(dá)轎車
離合器膜片彈簧的設(shè)計(jì)與 [D].fl春理工?學(xué),2008. [3] 許兆棠,劉永臣. 車構(gòu)造(下)[M].北京:
防工業(yè)出版社,2012. [4] 陳 德. 設(shè)計(jì) [M].北京:o 教育出版社,2013. [5] 馬·峰.離
合器ˉ型校核與應(yīng)用[J].現(xiàn)代車用 力,2012,3. [6] 徐?安,江 潮. 車離合器[M].北京:清華?學(xué)
出版社,2005. [7] 王望予. 車設(shè)計(jì)[M].北京: 工業(yè)出版社,2006. [8] 林世裕.膜片彈簧離合器
的演變 結(jié)構(gòu)形式與[J].江蘇工學(xué)院學(xué)報(bào),1990,11(1):7-18 [9] 朱茂桃,劉雪萊. 車離合器膜片
彈簧的優(yōu)化設(shè)計(jì)分析[J]. 設(shè)計(jì)與制造,2014,6. [10] 張文華.膜片彈簧式離合器的分析及優(yōu)化設(shè)計(jì)
[J].應(yīng)用?源`′,2009,12. [11] 紅.淺談 車膜片彈簧離合器[J].洛陽理工學(xué)院學(xué)報(bào),
2012,22(2). [12] 肖文穎,許海華. 車離合器膜片彈簧的優(yōu)化設(shè)計(jì)[J].公路與 運(yùn),
2007.121(4):9-10 [13] 韋遠(yuǎn)飛,朱啟庚.介紹?種自調(diào)試膜片彈簧離合器 [14] 余志生. 車?yán)碚?
[M].北京: 工業(yè)出版社,2000. [15] 林世裕.膜片彈簧與蝶形彈簧離合器的設(shè)計(jì)與制造[M].南京:東
南?學(xué)出版社,1995.
畢 業(yè) 設(shè) 計(jì)(論文) 開 題 報(bào) 告
2. ”題要 或?決的問題 擬采用的 ?(?徑):
2.1 內(nèi)容:(1) 車總– 設(shè)計(jì)(2)離合器ˉ型(3)離合器 要 的ˉ¨(4)膜片彈簧的設(shè)計(jì)
(5)離合器 總–設(shè)計(jì)(6)壓 離合器蓋設(shè)計(jì)(7) 轉(zhuǎn)減振器設(shè)計(jì)(8)離合器 縱 構(gòu)設(shè)計(jì) 2.2
設(shè)計(jì) § 設(shè)計(jì)要求對(duì) 車離合器的結(jié)構(gòu)型式??合理ˉ¨,再??離合器的 結(jié)構(gòu)尺寸 的ˉ¨及
計(jì)算; 后??離合器 要零 的結(jié)構(gòu)ˉ型及設(shè)計(jì)計(jì)算, 利用軟 ??必要的校核,繪制離合器零 圖。
畢 業(yè) 設(shè) 計(jì)(論文) 開 題 報(bào) 告
指導(dǎo)教師意見:
1.對(duì)“文獻(xiàn)綜述”的評(píng)語:
該同學(xué)對(duì) 車離合器的 展? ?? ?單綜述, 針對(duì)膜片彈簧離合器的結(jié)構(gòu) 特點(diǎn)?? 分析,對(duì)將要完
成的畢業(yè)設(shè)計(jì)內(nèi)容?? ?單闡述。文獻(xiàn)綜述寫作符合要求。
2.對(duì) ”題的深度 度及工作量的意見 對(duì)設(shè)計(jì)(論文)結(jié)果的預(yù)測(cè):
畢業(yè)設(shè)計(jì)ˉ題符合所學(xué)專業(yè) 向 專業(yè)要求,設(shè)計(jì)內(nèi)容切 可?,深度 度適 ,工作量 ,預(yù)計(jì)??完
成設(shè)計(jì)要求,同意開題。
3. 同意開題: 同意 同意
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2016 03 06
所在專業(yè)審查意見:
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2016 04 07
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譯文題目: 現(xiàn)代交通運(yùn)輸對(duì)環(huán)境和歷史的影響
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Environmental Impact and History of Modern Transportation
The development of internal combustion (IC) engine vehicles, and especially automobiles, is one of the greatest achievements of modern technology. Automobile shave made great contributions to the growth of modern society by satisfying many of the needs for mobility in everyday life. The rapid development of the automotive industry, unlike that of any other industry, has prompted the progress of human beings from a primitive security to a highly developed industrial one. The automobile industry and the other industries that serve it constitute the backbone of the world’s economy and employ the greatest share of the working population.
However, the large number of automobiles in use around the world has caused and continues to cause serious problems for environment and human life. Air pollution, global warming, and the rapid depletion of the Earth’s petroleum resources are now problems of paramount concern.
In recent decades, the research and development activities related to transportation have emphasized the development of high-efficiency, clean, and safe transportation. Electric vehicles (EVs), hybrid electric vehicles (HEVs),and fuel cell vehicles have been typically proposed to replace conventional vehicles in the near future.
This chapter reviews the problems of air pollution, gas emissions causing global warming, and petroleum resource depletion. It also gives a brief review of the history of EVs, HEVs, and fuel cell technology.
1.1 Air Pollution
At present, all vehicles rely on the combustion of hydrocarbon (HC) fuels to derive the energy necessary for their propulsion. Combustion is a reaction between the fuel and the air that releases heat and combustion products.The heat is converted to mechanical power by an engine and the combustion products are released to the atmosphere.An HC is a chemical compound with molecules made up of carbon and hydrogen atoms. Ideally, the combustion of an HC yields only carbon dioxide and water, which do not harm the environment. Indeed, green plants “digest” carbon dioxide by photosynthesis.Carbon dioxide is a necessary ingredient in vegetal life. Animals do not suffer from breathing carbon dioxide unless its concentration in air is such that oxygen is almost absent.
Actually, the combustion of HC fuel in combustion engines is never ideal.Besides carbon dioxide and water, the combustion products contain a certain amount of nitrogen oxides (NOx), carbon monoxides (CO), and unburned HCs,all of which are toxic to human health.
1.1.1 Nitrogen Oxides
Nitrogen oxides(NOx) result from the reaction between nitrogen in the air and oxygen. Theoretically, nitrogen is an inert gas. However, the high temperatures and pressures in engines create favorable conditions for the formation of nitrogen oxides. Temperature is by far the most important parameter in nitrogen oxide formation. The most commonly found nitrogen oxide is nitric oxide(NO), although small amounts of nitric dioxide (NO2) and traces of nitrous oxide (N2O) are present. Once released into the atmosphere, NO reacts with the oxygen to form NO2. This is later decomposed by the Sun’s ultraviolet radiation back to NO and highly reactive oxygen atoms that attack the membranes of living cells. Nitrogen dioxide is partly responsible for smog; its brownish color makes smog visible. It also reacts with atmospheric water to form nitric acid (HNO3), which dilutes in rain. This phenomenon is referred to as “acid rain” and is responsible for the destruction of forests in industrialized countries.Acid rain also contributes to the degradation of historical monuments made of marble.
1.1.2 Carbon Monoxide
Carbon monoxide results from the incomplete combustion of HCs due to a lack of oxygen.1 It is a poison to human beings and animals who inhale/breathe it. Once carbon monoxide reaches the blood cells, it fixes to the hemoglobin in place of oxygen, thus diminishing the quantity of oxygen that reaches the organs and reducing the physical and mental abilities of affected living beings.1 Dizziness is the first symptom of carbon monoxide poisoning, which can rapidly lead to death. Carbon monoxide binds more strongly to hemoglobin than oxygen. The bonds are so strong that normal body functions cannot break them. People intoxicated by carbon monoxide must be treated in pressurized chambers, where the pressure makes it easier to break the carbon monoxide–hemoglobin bonds.
1.1.3 Unburned HCs
Unburned HCs are a result of the incomplete combustion of HCs.1,2 Depending on their nature, unburned HCs may be harmful to living beings.2 Some of these unburned HCs may be direct poisons or carcinogenic chemicals such as particulates, benzene, or others. Unburned HCs are also responsible for smog:the Sun’s ultraviolet radiations interact with the unburned HCs and NO in the atmosphere to form ozone and other products. Ozone is a molecule formed of three oxygen atoms. It is colorless but very dangerous, and is poisonous because as it attacks the membranes of living cells, causing them to age prematurely or die. Toddlers, older people, and asthmatics suffer greatly from exposure to high ozone concentrations. Annually, deaths from high ozone peaks in polluted cities have been reported.3
1.1.4 Other Pollutants
Impurities in fuels result in the emission of pollutants. The major impurity is sulfur: mostly found in diesel and jet fuel, but also in gasoline and natural gas.1 The combustion of sulfur (or sulfur compounds such as hydrogen sulfide) with oxygen releases sulfur oxides (SOx). Sulfur dioxide (SO2) is the major product of this combustion. On contact with air, it forms sulfur trioxide, which later reacts with water to form sulfuric acid, a major component of acid rain. It should be noted that sulfur oxide emissions originate from transportation sources but also largely from the combustion of coal in power plants and steel factories. In addition, there is debate over the exact contribution of、natural sources such as volcanoes.
Petroleum companies add chemical compounds to their fuels in order to improve the performance or lifetime of engines.1 Tetraethy lead, often referred to simply as “l(fā)ead,” was used to improve the knock resistance of gasoline and therefore allow better engine performance. However, the combustion of this chemical releases lead metal, which is responsible for a neurological disease called “saturnism.” Its use is now forbidden in most developed countries and it has been replaced by other chemicals.1
1.2 Global Warming
Global warming is a result of the “greenhouse effect” induced by the presence of carbon dioxide and other gases, such as methane, in the atmosphere. These gases trap the Sun’s infrared radiation reflected by the ground, thus retaining the energy in the atmosphere and increasing the temperature. An increased Earth temperature results in major ecological damages to its ecosystems and in many natural disasters that affect human populations.2
Considering the ecological damages induced by global warming, the disappearance of some endangered species is a concern because this destabilizes the natural resources that feed some populations. There are also concerns about the migration of some species from warm seas to previously colder northern seas, where they can potentially destroy indigenous species and the economies that live off those species. This may be happening in the Mediterranean Sea, where barracudas from the Red Sea have been observed.
Natural disasters command our attention more than ecological disasters because of the amplitude of the damages they cause. Global warming is believed to have induced meteorological phenomena such as “El Ni?o,” which disturbs the South Pacific region and regularly causes tornadoes, inundations, and dryness. The melting of the polar icecaps, another major result of global warming, raises the sea level and can cause the permanent inundation of coastal regions and sometimes of entire countries.
Carbon dioxide is the result of the combustion of HCs and coal. Transportation accounts for a large share (32% from 1980 to 1999) of carbon dioxide emissions. The distribution of carbon dioxide emissions is shown in Figure 1.1.4
Figure 1.2 shows the trend in carbon dioxide emissions. The transportation sector is clearly now the major contributor to carbon dioxide emissions. It should be noted that developing countries are rapidly increasing their transportation sector, and these countries represent a very large share of the world population. Further discussion is provided in the next subsection.
The large amounts of carbon dioxide released into the atmosphere by human activities are believed to be largely responsible for the increase in the global Earth temperature observed during the last decades (Figure 1.3).It is important to note that carbon dioxide is indeed digested by plants and sequestrated by oceans in the form of carbonates. However, these natural assimilation processes are limited and cannot assimilate all of the emitted carbon dioxide, resulting in an accumulation of carbon dioxide in the Atmosphere.
1.3 Petroleum Resources
The vast majority of fuels for transportation are liquid fuels originating from petroleum. Petroleum is a fossil fuel, resulting from the decomposition of living matters that were imprisoned millions of years ago (Ordovician,600–400 million years ago) in geologically stable layers. The process is roughly the following: living matters (mostly plants) die and are slowly covered by sediments. Over time, these accumulating sediments form thick layers and transform to rock. The living matters are trapped in a closed space, where they encounter high pressures and temperatures and slowly transform into either HCs or coal, depending on their nature. This process takes millions of years to accomplish. This is what makes the Earth’s resources in fossil fuels finite.
Proved reserves are “those quantities that geological and engineering information indicates with reasonable certainty can be recovered in the future from known reservoirs under existing economic and operating conditions.”5 Therefore, they do not constitute an indicator of the Earth’s total reserves. The proved reserves, as they are given in the British Petroleum 2001 estimate,5 are given in billion tons in Table 1.1. The R/P ratio is the number of years that the proved reserves would last if the production were to continue at its current level. This ratio is also given in Table 1.1 for each region.5
The oil extracted nowadays is the easily extract able oil that lies close to the surface, in regions where the climate does not pose major problems. It is believed that far more oil lies underneath the Earth’s crust in regions such as Siberia, or the American and Canadian Arctic. In these regions, the climate and ecological concerns are major obstacles to extracting or prospecting for oil. The estimation of the total Earth’s reserves is a difficult task for political and technical reasons. A 2000 estimation of the undiscovered oil resources by the US Geological Survey is given in Table 1.2.6 Although the R/P ratio does not include future discoveries, it is significant. Indeed, it is based on proved reserves, which are easily accessible to this day. The amount of future oil discoveries is hypothetical, and the newly discovered oil will not be easily accessible. The R/P ratio is also based on the hypothesis that the production will remain constant. It is obvious, however, that consumption (and therefore production) is increasing yearly to keep up with the growth of developed and developing economies. Consumption is likely to increase in gigantic proportions with the rapid development of some largely populated countries,particularly in the Asia-Pacific region. Figure 1.4 shows the trend in oil consumption over the last 20 years.7 Oil consumption is given in thousand barrels per day (one barrel is about 8 metric tons). Despite the drop in oil consumption for Eastern Europe and the former USSR, the world trend is clearly increasing, as shown in Figure 1.5. The fastest growing region is Asia Pacific, where most of the world’s population lives.An explosion in oil consumption is to be expected, with a proportional increasein pollutant emissions and CO2 emissions.
1.4 Induced Costs
The problems associated with the frenetic combustion of fossil fuels are many: pollution, global warming, and foreseeable exhaustion of resources, among others.Although difficult to estimate, the costs associated with these problems are huge and indirect,8 and may be financial, human, or both.
Costs induced by pollution include, but are not limited to, health expenses, the cost of replanting forests devastated by acid rain, and the cost of cleaning and fixing monuments corroded by acid rain. Health expenses probably represent the largest share of these costs, especially in developed countries with socialized medicine or health-insured populations.
Costs associated with global warming are difficult to assess. They may include the cost of the damages caused by hurricanes, lost crops due to dryness, damaged properties due to floods, and international aid to relieve the affected populations. The amount is potentially huge.
Most of the petroleum-producing countries are not the largest petroleum consuming
countries. Most of the production is located in the Middle East, while most of the consumption is located in Europe, North America, and Asia Pacific. As a result, consumers have to import their oil and depend on the producing countries. This issue is particularly sensitive in the Middle East, where political turmoil affected the oil delivery to Western countries in 1973 and 1977. The Gulf War, the Iran–Iraq war, and the constant surveillance of the area by the United States and allied forces come at a cost that is both human and financial. The dependency of Western economies on a fluctuating oil supply is potentially expensive. Indeed, a shortage in oil supply
causes a serious slowdown of the economy, resulting in damaged perishable goods, lost business opportunities, and the eventual impossibility to run businesses.
In searching for a solution to the problems associated with oil consumption, one has to take into account those induced costs. This is difficult because the cost is not necessarily asserted where it is generated. Many of the induced costs cannot be counted in asserting the benefits of an eventual solution. The solution to these problems will have to be economically sustainable and commercially viable without government subsidies in order to sustain itself in the long run. Nevertheless, it remains clear that any solution to these problems— even if it is only a partial solution—will indeed result in cost savings, which will benefit the payers.
現(xiàn)代交通運(yùn)輸對(duì)環(huán)境和歷史的影響
內(nèi)燃機(jī)的發(fā)展,車輛發(fā)動(dòng)機(jī)的發(fā)展,特別是汽車,是現(xiàn)代科技的最偉大的成就之一。汽車為現(xiàn)代社會(huì)的發(fā)展作出了巨大貢獻(xiàn)。滿足了日常通行的便利性。汽車行業(yè)的快速發(fā)展不像其他行業(yè)一樣,是促使人類從原始安全高度進(jìn)步的發(fā)達(dá)工業(yè)之一。汽車產(chǎn)業(yè)和其服務(wù)產(chǎn)業(yè)構(gòu)成了世界經(jīng)濟(jì)的支柱,占據(jù)了勞動(dòng)人口的最大份額。
然而,在世界各地由于使用大量的汽車引起的并繼續(xù)給環(huán)境和人類的生活造成嚴(yán)重的問題。空氣污染,全球變暖,地球上石油資源快速損耗的問題在現(xiàn)在看來至關(guān)重要。
近幾十年來,研究和運(yùn)輸有關(guān)的開發(fā)活動(dòng)強(qiáng)調(diào)發(fā)展高效、清潔和安全的運(yùn)輸。在不久的將來電動(dòng)車,混合動(dòng)力電動(dòng)汽車和燃料電池汽車被提出取代傳統(tǒng)的車輛。
本章回顧了空氣污染的問題,氣體排放造成的全球變暖,和石油資源枯竭的問題。同時(shí)也簡(jiǎn)要回顧了電動(dòng)汽車的歷史、混合動(dòng)力汽車和燃料電池技術(shù)。
1.1 空氣污染
目前,所有汽車依賴碳?xì)浠衔锶剂系娜紵裏岖@得所需的能源推進(jìn)。燃燒是一個(gè)反應(yīng)燃料和空氣之間的釋放熱量和燃燒產(chǎn)物的關(guān)系。熱量轉(zhuǎn)化為機(jī)械動(dòng)力傳遞到發(fā)動(dòng)機(jī)和燃燒產(chǎn)品釋放到大氣中。碳?xì)浠衔锸且环N由碳和氫的原子組成的分子。理想情況下,燃燒碳?xì)浠衔锏氖找媛手挥卸趸己退?不傷害環(huán)境。實(shí)際上,綠色植物通過光合作用“消化”二氧化碳。二氧化碳是植物生活的必要組成部分。動(dòng)物呼吸二氧化碳不會(huì)導(dǎo)致生病除非在空氣中它的濃度過高而導(dǎo)致沒有氧氣一樣。
實(shí)際上,碳?xì)浠衔锶剂系娜紵趦?nèi)燃機(jī)中從來都不是理想的。除了二氧化碳和水,燃燒包含一個(gè)特定的產(chǎn)品:大量的氮氧化物(NOx),一氧化碳(CO),未燃燒的高碳化合物,所有的這一些對(duì)人體健康都是有害的。
1.1.1氮氧化物
氮氧化物(NOx)與空氣中氮?dú)庵g的反應(yīng)結(jié)果是氧氣。從理論上講,氮?dú)馐且环N惰性氣體。然而,發(fā)動(dòng)機(jī)的高溫和高壓為氮氧化物的形成創(chuàng)造有利條件。溫度是氮氧化物形成的最重要的參數(shù)。最常見的氮氧化物是一氧化氮(NO),盡管也有少量的二氧化碳(NO2)和一氧化二氮(N2O)。一旦釋放到大氣中,一氧化氮與氧氣形成NO2。后來被太陽的紫外線分解輻射回到一氧化氮和高度活性氧原子攻擊細(xì)胞膜的活細(xì)胞。二氧化氮是煙霧的形成部分,它的存在使煙霧形成可見的褐色。它還與大氣中的水反應(yīng)形成硝酸(HNO3)稀釋在雨中。這種現(xiàn)象被稱為“酸雨”,就是這種物質(zhì)在工業(yè)化國(guó)家破壞森林。酸雨也有助于大理石古跡的退化。
1.1.2一氧化碳
碳?xì)浠衔镉捎谌鄙傺鯕鈱?dǎo)致不完全燃燒的結(jié)果是產(chǎn)生一氧化碳。一旦呼吸/吸入它對(duì)人類和動(dòng)物來說是毒藥。一旦一氧化碳到達(dá)血液細(xì)胞,它就會(huì)與血紅蛋白中的氧結(jié)合,從而減少到達(dá)器官的氧氣含量,影響生物的身體和精神能力。
1.1.3未燃碳?xì)浠衔?
未燃碳?xì)浠衔飳?dǎo)致碳?xì)浠衔锊煌耆紵慕Y(jié)果。根據(jù)其本質(zhì)上來講,未燃的碳?xì)浠衔锟赡苡泻ι铩2糠诌@些未燃的碳?xì)浠衔镉锌赡苤苯雍杏卸绢w粒、苯或其他致癌化學(xué)物質(zhì)危害人體健康。未燃的碳?xì)浠衔镞€會(huì)產(chǎn)生煙霧,太陽的紫外線輻射與未燃的碳?xì)浠衔镉羞€有大氣中的一氧化氮形成臭氧臭氧和其他產(chǎn)品。臭氧是一種由三個(gè)氧原子組成的分子。它是無色的,但非常危險(xiǎn),是有毒的。因?yàn)樗艋罴?xì)胞的細(xì)胞膜,使它們過早老化或死亡。幼兒、老年人和哮喘患者遭受很大威脅當(dāng)暴露于高濃度臭氧中。每年有很多報(bào)道關(guān)于死于高濃度臭氧。
1.1.4其他污染物
雜質(zhì)的燃料導(dǎo)致污染物的排放。主要的雜質(zhì)是硫:主要是柴油和噴氣燃料中,也存在在汽油和天然氣中。硫的燃燒(或硫化物如硫化氫)與氧氣形成硫氧化物(SOx)。二氧化硫(SO2)是這個(gè)燃燒的主要產(chǎn)品。它與空氣接觸后形成三氧化硫,后來又與水反應(yīng)生成硫酸。酸雨的主要組成部分。應(yīng)該注意的是,硫氧化物排放源也主要來自燃燒煤炭的發(fā)電廠和鋼鐵工廠。此外,還有爭(zhēng)論的是火山等自然資源。
石油公司將化學(xué)物質(zhì)添加到他們的燃料中來提高他們發(fā)動(dòng)機(jī)性能。四乙鉛,經(jīng)常被簡(jiǎn)稱為“領(lǐng)導(dǎo)”,用于改善汽油的爆震阻力,用了獲得更好的發(fā)動(dòng)機(jī)的性能。然而,燃燒這種化學(xué)物質(zhì)釋放鉛金屬,這種金屬會(huì)產(chǎn)生神經(jīng)系統(tǒng)疾病,稱為“鉛毒。現(xiàn)在在大多數(shù)發(fā)達(dá)國(guó)家已經(jīng)禁止使用這種金屬,它已經(jīng)被其他化學(xué)物質(zhì)取代了。
1.2全球變暖
全球變暖是由”溫室效應(yīng)”而引起的問題,“溫室效應(yīng)”是空氣中的二氧化碳和其他氣體引起的,如甲烷。在大氣中,這些氣體阻隔了地面太陽的紅外輻射反射,從而留住大氣中的能量和增加溫度。增加地球溫度將導(dǎo)致其生態(tài)系統(tǒng)遭到損害,發(fā)生自然災(zāi)害影響人類生產(chǎn)活動(dòng)??紤]到全球變暖而引起的生態(tài)破壞,一些瀕危物種的消失也是一個(gè)值得關(guān)注的焦點(diǎn)因?yàn)檫@些些也是人類生活的組成部分。也有擔(dān)心的是一些物種的遷移是從溫暖的海洋到寒冷的北方海域,他們可能會(huì)破壞當(dāng)?shù)匚锓N種類和當(dāng)?shù)赝林慕?jīng)濟(jì)生活。這可能發(fā)生在地中海,因?yàn)榧t海已經(jīng)有梭魚能夠看到了。
自然災(zāi)害引起我們的注意力超過生態(tài)災(zāi)害。因?yàn)樗麄冊(cè)斐傻膿p害的范圍與頻率。全球變暖是被認(rèn)為誘導(dǎo)氣象的現(xiàn)象,如“厄爾尼諾現(xiàn)象”,它擾亂了南太平洋地區(qū),經(jīng)常引起龍卷風(fēng)、洪水和干旱等問題。另一個(gè)全球變暖的結(jié)果就是極地冰帽的融化,從而導(dǎo)致海平面的提高,這可能在沿海地區(qū)導(dǎo)致整個(gè)國(guó)家永久性的洪水。
二氧化碳是碳?xì)浠衔锖兔喝紵慕Y(jié)果。交通運(yùn)輸產(chǎn)生的二氧化碳占了很大份額從1980年到1999年(32%)。現(xiàn)在的交通行業(yè)顯然是二氧化碳排放的主要因素。應(yīng)該指出的是,發(fā)展中國(guó)家的交通行業(yè)也在迅速增長(zhǎng),和這些國(guó)家代表世界非常大的人口份額。在接下來的小節(jié)提供進(jìn)一步討論。
人類活動(dòng)產(chǎn)生的大量的二氧化碳釋被排放到大氣中,這被認(rèn)為是全球氣溫升高的主要因素。從過去的幾十年里觀察,值得注意的是,確實(shí)消化二氧化碳是通過植物和海洋中的海洋生物。然而,這些自然同化過程是有限的,不能吸收所有排放的二氧化碳,這導(dǎo)致在大氣中二氧化碳的快速積聚。
1.3石油資源
絕大多數(shù)的交通運(yùn)輸液體燃料來自石油。石油是一種化石燃料,是從數(shù)百萬年前德地質(zhì)穩(wěn)定層的生物得來的。這個(gè)過程大約是:生物(主要是植物)死亡,正在慢慢地覆蓋沉積物。隨著時(shí)間的推移,這些沉積物積累形成厚層并且變換成巖石。生物被困在一個(gè)封閉的空間,在那里遇到高壓力和高溫度,它們慢慢轉(zhuǎn)變成碳?xì)浠衔锘蛎禾浚@取決于他們的本質(zhì)。這個(gè)過程需要數(shù)百萬年來完成。這就是什么形成地球上有限的化石燃料資源。
探明儲(chǔ)量是“從已知的現(xiàn)有經(jīng)濟(jì)和操作條件下,合理明確表明在未來可以恢復(fù)的那些地質(zhì)和工程信息的數(shù)量”。因此,他們不構(gòu)成地球的總儲(chǔ)量的一項(xiàng)指標(biāo)。探明儲(chǔ)量,就像英國(guó)石油公司在2001年估計(jì),R / P比值的表明探明儲(chǔ)量將持續(xù)減少如果生產(chǎn)繼續(xù)以當(dāng)前的水平開采。
現(xiàn)在提煉出來的油是在表面最容易提煉出來的油。不同地區(qū)氣候的的不同對(duì)提煉石油不構(gòu)成重大問題。他們相信很多地區(qū)的更多的石油位于地殼下面,比如西伯利亞,美國(guó)和加拿大北部。在這些地區(qū),氣候和生態(tài)問題是提取或勘探石油的主要障礙。地球石油資源總儲(chǔ)備的估計(jì)在政治上是一項(xiàng)艱巨的任務(wù)。
盡管R / P比值不包括未來石油的發(fā)現(xiàn),但它是重要的。事實(shí)上,它是基于探明儲(chǔ)量,這很與今天的情況很接近。假設(shè),未來的石油發(fā)現(xiàn)量和新發(fā)現(xiàn)石油不會(huì)容易。R / P比值也是保持不變。然而,由于發(fā)展中國(guó)家和發(fā)展中經(jīng)濟(jì)的增長(zhǎng),很明顯消費(fèi)(因此生產(chǎn))每年在增加。在一些主要國(guó)家人口的的快速發(fā)展,消費(fèi)是有巨大的可能會(huì)增加,尤其是在亞太地區(qū)。
盡管在東歐和前蘇聯(lián)石油消費(fèi)量在下降,但在世界上石油消費(fèi)量趨勢(shì)明顯增加,尤其在發(fā)展最快的亞太地區(qū),世界上大部分的人口住在哪里。很快就會(huì)到達(dá)石油爆炸的消費(fèi)時(shí)期。石油消費(fèi)量比例在增加而污染物排放和二氧化碳排放也在增加。