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Tianjin, China

Zheng Q.-P.,Hebei University of Technology | Li S.,Hebei University of Technology | Lang X.-J.,Hebei University of Technology | Zhang K.-P.,Tianjin Lovol Engines Co.
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2012

Established one-dimensional thermodynamic model for a turbocharged inter-cooled diesel engine with exhaust gas recirculation (EGR) system, the numerical simulation was carried out. Comparison of simulated and experimental results shows that both are consistent, error is in reasonable scope. On this basis, the influences of EGR on engine power output, specific fuel consumption and emissions were studied for different operating conditions, and the EGR system was optimized according to comprehensive performance of the engine to obtain ideal EGR control MAP. Experimental results on the platform built based on simulated results show that the soot and NO x emissions according to 13 model cycle are 3.0 g/(kW·h) and 0.45 g/(kW·h) respectively, satisfying Euro IV emission standards.

Yao C.-D.,Tianjin University | Liu J.-H.,Tianjin University | Wei L.-J.,Tianjin University | Xia Q.,Tianjin University | Li F.-C.,Tianjin Lovol Engines Co.
Ranshao Kexue Yu Jishu/Journal of Combustion Science and Technology | Year: 2012

Diesel/ethanol compound combustion(DECC) was investigated, in which ethanol blended with water(30% volume fraction of water in the blend)was injected into the intake port to fumigate mixture as pretreatment. The testing results showed that the intake pretreatment of ethanol injected into intake port could remarkably reduce nitrogen oxides(NO x), nitric oxide(NO)and smoke emissions simultaneously. Nitrogen dioxide(NO 2) emissions decreased at high engine load but increased at low load. Unburned hydrocarbons(HC) and carbon monoxide(CO) emissions increased, but they could be eliminated by means of diesel oxidation catalytic converter (DOC), the catalytic efficiency of DOC was more than 96%. The emissions of formaldehyde and acetaldehyde increased in general, however, they both could be reduced by more than 91% with DOC, approximately to the level of baseline engine. Experimental results also indicated that, with intake injected ethanol pretreatment, the brake thermal efficiency of engine could be improved obviously and the fuel economy increased.

Li S.,Hebei University of Technology | Zheng Q.,Hebei University of Technology | Zhang K.,Tianjin Lovol Engines Co. | Liu G.,Hebei University of Technology | Zhang S.,Hebei University of Technology
Nongye Jixie Xuebao/Transactions of the Chinese Society of Agricultural Machinery | Year: 2012

Fluid-solid coupled heat transfer simulation of cylinder head in CNG engine were carried out by using CFD software, the temperature field and the flow field of cylinder head were achieved and investigated. Calculating results were compared with the experimental results in order to validate the veracity of model. Improvements refer to gasket hole area have been presented according to the problems in calculation results. The cooling effect was improved by increasing water flow quantity in the vicinity of fifth cylinder and decreasing the water flow quantity near the first and second cylinders.

Pan S.-Z.,Tianjin University | Pei Y.-Q.,Tianjin University | Song C.-L.,Tianjin University | Lu G.,Tianjin University | And 3 more authors.
Ranshao Kexue Yu Jishu/Journal of Combustion Science and Technology | Year: 2012

A DMS, 500 fast particulate spectrometer was employed to characterize the particle size distribution from a port fuel injection(PFI) gasoline engine which meets the regulations of China III standards. The results show that exhaust particulates from gasoline engine are dominated by nucleation mode particles, with accumulation mode particles generated only under some conditions. Under an idle condition, exhaust particles exhibit a bimodal size distribution consisting of nucleation mode and accumulation mode. Particle number size distribution shows a unimodal nucleation mode at low engine speed and a large size distribution involving nucleation mode and accumulation mode at middle engine speed. At the constant speed, the peak value of number concentration for nucleation mode shows an increasing trend after an initial decrease with the increase of engine load. At the constant load, both the peak value of number concentration and the peak diameter for nucleation mode drop with the increase of engine speed, while the peak value of number concentration for accumulation mode shows an increasing trend with the increase of engine speed. Conversion efficiency of three-way catalyst(TWC) is high for nucleation mode particles, while it is low for accumulation mode particles. Furthermore, particle size distribution varies greatly between the upstream and downstream of TWC when engine runs at low speed.

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