目前兩所英國(guó)頂尖科技大學(xué)正在牽頭進(jìn)行的兩個(gè)研究項(xiàng)目，一是通過(guò)設(shè)計(jì)來(lái)降低催化轉(zhuǎn)換器的成本，另一個(gè)是通過(guò)更先進(jìn)的渦輪增壓與燃燒技術(shù)來(lái)降低發(fā)動(dòng)機(jī)的排放。
在倫敦的帝國(guó)理工學(xué)院，化學(xué)工程學(xué)院的研究員Benjamin Kingsbury博士正在領(lǐng)導(dǎo)團(tuán)隊(duì)開(kāi)發(fā)生產(chǎn)流程，以達(dá)到大批量生產(chǎn)一款新型催化轉(zhuǎn)換器的目的，旨在提高汽車燃油效率，并降低生產(chǎn)成本。
而巴斯大學(xué)動(dòng)力傳動(dòng)系統(tǒng)與車輛研究中心（PVRC）正在開(kāi)展一個(gè)由政府和企業(yè)界共同投資的“綠色汽車”項(xiàng)目，該項(xiàng)目總資金達(dá)到1.33億英鎊, 由該研究中心新設(shè)立的高級(jí)推進(jìn)中心（APC）負(fù)責(zé)實(shí)施。PVRC中心曾主導(dǎo)研發(fā)了福特汽車1.0-L I3 EcoBoost發(fā)動(dòng)機(jī)。APC由英國(guó)汽車協(xié)會(huì)與行業(yè)共同建立，匯聚了先進(jìn)傳動(dòng)技術(shù)領(lǐng)域的優(yōu)秀人才，研究領(lǐng)域包括改進(jìn)燃油效率、降低碳排放、以及將技術(shù)轉(zhuǎn)化為產(chǎn)品等等。
催化劑載體的改進(jìn)
Kingsbury博士與Kang Li教授、Zhentao Wu博士一起著手進(jìn)行催化轉(zhuǎn)換器的研發(fā)，后兩位教授也是帝國(guó)理工學(xué)院化學(xué)工程學(xué)院的研究員。早期的測(cè)試顯示，這項(xiàng)技術(shù)可將燃耗降低3%左右，而二氧化碳的排放也會(huì)隨之降低。
Kingsbury博士表示，他們研發(fā)的催化轉(zhuǎn)換器設(shè)計(jì)可以減少80%的貴金屬（鉑族元素）用量，這將大大降低生產(chǎn)成本。此外，該設(shè)計(jì)還能減輕整個(gè)壽命周期內(nèi)的材料劣化。通常，稀有金屬占到一個(gè)催化轉(zhuǎn)換器成本的70%。而在10萬(wàn)公里（161,000mi）的測(cè)試中，新系統(tǒng)只顯示出4%的劣化率，而一個(gè)普通的催化轉(zhuǎn)換器的材料劣化率則高達(dá)35%。
帝國(guó)理工學(xué)院的一位發(fā)言人表示，Kingsbury博士已經(jīng)就該系統(tǒng)與數(shù)家汽車公司進(jìn)行了接觸。同時(shí)，他還成立了一家帝國(guó)理工學(xué)院下屬的創(chuàng)業(yè)公司，負(fù)責(zé)對(duì)系統(tǒng)進(jìn)行市場(chǎng)推廣。
Kingsbury博士表示，他們并未對(duì)汽車中的“Cats（三元催化器）”的基本設(shè)計(jì)做重大改變，因?yàn)檫@項(xiàng)技術(shù)在上世紀(jì)70年代中期就已經(jīng)成為美國(guó)輕型汽車排放控制系統(tǒng)的一部分，并在十年后被普及到歐洲。他們所做的，是在設(shè)計(jì)中加入了閉環(huán)反饋機(jī)制，對(duì)原設(shè)計(jì)進(jìn)行了提升，通過(guò)將氮氧化物轉(zhuǎn)化成氮?dú)夂退?，大大降低了顆粒物的排放。
“我開(kāi)發(fā)的原型可以降低汽車的運(yùn)行成本，因?yàn)樗娜加陀昧拷档土耍?/span>”Kingsbury表示。“它可以幫助汽車制造商降低成本，節(jié)約燃油成本，并最終降低二氧化碳的排放。”
Kingsbury說(shuō)，他還對(duì)一個(gè)現(xiàn)有的制造工藝進(jìn)行了改進(jìn)，以優(yōu)化轉(zhuǎn)換器的蜂窩狀基材的結(jié)構(gòu)。這一改進(jìn)的原理，是通過(guò)增加基材表面積來(lái)提高稀有金屬的分布效果，并減少其用量。增大基材表面積還可以增強(qiáng)系統(tǒng)的化學(xué)反應(yīng)，降低排氣背壓。
帝國(guó)理工學(xué)院的一篇新聞稿稱，Kingsbury博士已經(jīng)獲得英國(guó)皇家工程院的資助，用于該系統(tǒng)的市場(chǎng)推廣。
與福特合作的ACTIVE項(xiàng)目
作為福特ACTIVE（先進(jìn)渦輪增壓燃燒內(nèi)嵌式可變氣門機(jī)構(gòu)發(fā)動(dòng)機(jī)）項(xiàng)目的11名研究合作伙伴之一，巴斯大學(xué)的PVRC獲得了120萬(wàn)英鎊的投資。該項(xiàng)目的中心研究項(xiàng)目是1.0-L EcoBoost發(fā)動(dòng)機(jī)，目前該發(fā)動(dòng)機(jī)已經(jīng)應(yīng)用到福特的數(shù)個(gè)車型上。
這一項(xiàng)目的出發(fā)點(diǎn)是為幫助加速下一代低碳技術(shù)推出市場(chǎng)，這項(xiàng)技術(shù)旨在通過(guò)先進(jìn)渦輪增壓和燃燒系統(tǒng)的開(kāi)發(fā)，輔以尖端的可變氣門機(jī)構(gòu)技術(shù)，實(shí)現(xiàn)降低二氧化碳排放的目標(biāo)。
PVRC的汽車工程學(xué)講師Sam Akehurst博士解釋說(shuō)：“PVRC在福特的ACTIVE項(xiàng)目中的主要任務(wù)是研究新型渦輪增壓器和新型可變氣門正時(shí)技術(shù)的基本性能與互動(dòng)機(jī)制。我們將研究由于排氣閥開(kāi)啟時(shí)每個(gè)氣缸的排空所造成的發(fā)動(dòng)機(jī)排氣脈動(dòng)氣流和渦輪增壓機(jī)構(gòu)的相互作用機(jī)制。”
這一研究將通過(guò)兩種方式完成：第一種是直接在發(fā)動(dòng)機(jī)上進(jìn)行研究，第二種是借助PVRC正在研發(fā)的一種獨(dú)特的“熱脈動(dòng)渦輪增壓氣站(hot pulsating turbocharger gas stand)”進(jìn)行研究。這兩種方法都能支持高級(jí)模擬技術(shù)的驗(yàn)證，以幫助福特公司了解怎樣才能最好地利用這些新科技。
“研究的目的是同時(shí)優(yōu)化發(fā)動(dòng)機(jī)和渦輪增壓器的性能，從而使發(fā)動(dòng)機(jī)扭矩、燃油經(jīng)濟(jì)性和瞬態(tài)響應(yīng)的整體狀況都達(dá)到最佳水平。” Akehurst博士告訴《汽車工程》期刊的記者。
巴斯大學(xué)工程與設(shè)計(jì)學(xué)院院長(zhǎng)兼PVRC主任Gary Hawley教授補(bǔ)充道：“我們對(duì)該項(xiàng)目的參與延續(xù)了我們對(duì)EcoBoost發(fā)動(dòng)機(jī)研發(fā)的巨大貢獻(xiàn)。”他表示，這些成果都是建立在巴斯大學(xué)在降低汽車發(fā)動(dòng)機(jī)二氧化碳排放方面，特別是在模擬復(fù)雜技術(shù)與系統(tǒng)的性能和表現(xiàn)方面的實(shí)力之上的。
福特的ACTIVE研究項(xiàng)目的參與方包括4所在汽車技術(shù)研究方面居于領(lǐng)先地位的英國(guó)大學(xué)（巴斯大學(xué)、拉夫伯勒大學(xué)、布拉德福德大學(xué)和諾丁漢大學(xué)），部件和設(shè)備供應(yīng)商，如大陸、舍弗勒、UEES, Cambustion、AP Raicam，以及像英國(guó)石油（BP）這樣的能源公司。
Reducing the cost of catalytic converters through design, and reducing engine-out emissions using advanced turbocharging and combustion techniques, are the focus of recent U.K.-based research projects spearheaded by two leading technical universities.
At Imperial College, London, Dr. Benjamin Kingsbury, a Research Associate in the Dept. of Chemical Engineering, is heading a project to develop a production process for high volume manufacture of a new catalytic converter aimed at both improving vehicle fuel consumption while offering production cost savings.
And the University of Bath’s Powertrain and Vehicle Research Center (PVRC), which had a significant role in the development of Ford’s 1.0-L I3 EcoBoost engine, is taking part in a £133 million government-and-industry-backed “greener cars” program. The work is being carried out by the new Advanced Propulsion Center (APC), a joint industry and government body established by the U.K. Automotive Council to become a hub of excellence for advanced powertrain technology, including improvements to fuel efficiency and reduction in carbon emissions — and to migrate technologies into products.
Catalyst substrate improvements
Dr. Kingsbury developed the catalytic converter together with Prof. Kang Li and Dr. Zhentao Wu, who are also with Imperial College’s Dept. of Chemical Engineering. Early tests indicate a potential fuel consumption benefit of around 3%, with a complementary reduction in CO2 emissions.
Dr. Kingsbury said the catalytic converter’s design uses up to 80% less precious metals (platinum group), which brings significant cost reduction. The design is also said to suffer less through-life degradation. Typically, rare metals represent up to 70% of the cost of a catalytic converter. Laboratory tests indicate a 4% deterioration over 100,000 km (161,000 mi) for the new system, compared to a claimed 35% deterioration for a regular catalytic converter.
A spokesperson for Imperial College says Kingsbury has been in contact with several auto industry companies regarding the new system. He has initiated an Imperial start-up company to market it.
According to Kingsbury, the fundamental design of automotive "cats" has not significantly changed since the technology became an integral part of light-vehicle emissions control systems in the mid-1970s in the U.S., and in Europe about a decade later. The adoption of closed-loop feedback capability improved the original design by markedly reducing emission of particulates via conversion of NOx into nitrogen and water.
“The prototype I have developed could make cars cheaper to run because they use less fuel," Kingsbury said. "It could potentially help manufacturers to reduce their costs and it could also save on fuel costs and ultimately lead to reduced CO2 emissions.”
He explained that he has advanced an existing manufacturing process to improve the structure of the catalytic converter’s honeycombed substrate. The effect is to increase the surface area, which facilitates the rare metals being distributed more effectively and fewer being required. The increased surface area also results in an enhancement of the system’s chemical reaction process. Exhaust back pressure is also reduced, he claimed.
Dr. Kingsbury has received funding from the Royal Academy of Engineering to take his system to the marketplace, according to a release from Imperial College.
Project ACTIVE with Ford
At the University of Bath, the PVRC has been awarded £1.2m to carry out research as one of Ford’s 11 partners on Project ACTIVE (Advanced Combustion Turbocharged In-line Variable Valvetrain Engine), which centers on the 1.0-L EcoBoost, now powering several of the company’s models.
The basis of the project is to help accelerate the introduction of future generation low-carbon technologies aimed at reducing CO2 via advanced turbocharging and combustion system development, complemented by highly sophisticated variable valvetrain technology.
Dr. Sam Akehurst, Lecturer in Automotive Engineering at the PVRC, explained: “The PVRC's role in the Ford-led ACTIVE program is to investigate the fundamental performance and interactions of a new type of turbocharger with new variable valve timing technology. We will study how the turbocharger interacts with the pulsating flow in the engine exhaust due to the blow-down events that occur from each cylinder as the exhaust valve opens."
This will be done in two ways—on engine and by utilising a unique hot pulsating turbocharger gas stand that the PVRC is developing. Both of these methods will support the validation of advanced simulation techniques aimed at assisting Ford in making decisions on how best to use the new technologies.
"The objectives are to optimise the performance of the engine and turbocharger in unison to achieve best performance in terms of overall engine torque, fuel economy and good transient response,” Dr. Akehurst told Automotive Engineering.
Prof. Gary Hawley, Dean of the Engineering and Design faculty, and Director of the PVRC, added: “Our involvement in this project continues the high impact contribution that we made to the development of the EcoBoost engine.” He said it builds on the University’s capability to emulate the performance and behavior of complex technologies and systems to drive down the car-engine CO2 footprint.
Along with Ford, the ACTIVE project involves four of the U.K.’s leading automotive research universities (Bath, Loughborough, Bradford, and Nottingham), as well as component and equipment suppliers including Continental, Schaeffler, UEES, Cambustion, AP Raicam, and the energy company BP.
巴斯大學(xué)動(dòng)力傳動(dòng)系統(tǒng)與車輛研究中心主任Gary Hawley教授
A test cell at the University of Bath's research facility.