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Gasoline compression ignition (GCI) is a highly feasible way to obtain high efficiency and low emissions simultaneously without many modifications of standard diesel engines. Exhaust gas recirculation (EGR) is an indispensable technology to achieve high efficiency and low emissions. A series of experimental studies were carried out to investigate the co-effect of EGR and fuel octane number on GCI combustion and emissions under all loads. Four primary reference fuels (PRF) with the research octane number of 90, 80, 70 and 60 were applied in this paper, which were denoted as PRF90, PRF80, PRF70 and PRF60. The results showed that high efficiency and low NOx emissions could be obtained under all loads by adjusting fuel octane number and EGR rate. PRF70 obtained the indicated thermal efficiency of above 47% by using the EGR rate of 30% and 40% under 6 bar and 8 bar, respectively. The increase in the EGR rate could decrease the oxygen content, thus reducing the NOx emissions. The EGR rate of 30% under 4–6 bar and the EGR rate of 40% under 8–12 bar could reduce the NOx emissions to below 300 ppm and 500 ppm, respectively. The effect of EGR on particle emissions was different under different loads. The increasing EGR rate reduced the particle emissions under low and medium loads, but increased the particle emissions under high loads due to the low volumetric efficiency. In addition, PRF90 with lower reactivity produced more methane, isopentane and aldehyde emissions than other fuels.

In recent years, electric vehicle ownership keeps rising. Meanwhile, the attention on post-collision safety of electric vehicles is becoming higher and higher. This paper proposes the necessity for adding rear collision requirements for electric vehicles, analyzes improvement schemes for four anti-HV electric shock protection measures and puts forward the idea of equivalent test on the basis of analysis of post-collision electrical safety of electric vehicles at home and abroad, which can provide reference for guiding product design of electric vehicles and perfecting applicable standards and regulations. In the meantime, the study achievements will be applied to revision of national standard GB/T 31498-2015 in China.

Rice-fish system is the first globally important agricultural heritage system (GIAHS) and could be a potential option to improve modern rice production. This paper investigates energy flows and eco...

As a renewable fuel, butanol has a higher energy density than short-chain alcohols, and can be mixed with diesel in any proportion. To analyze the particulate matter emissions of butanol isomer in compression ignition engines, in this paper, the four butanol isomers were blended with diesel (25 vol%) named as n-butanol/diesel, s-butanol/diesel, i-butanol/diesel and t-butanol/diesel. The characteristics of particulate matter emissions were studied under a wide range of engine loads (3bar–9bar) and exhaust gas recirculation (EGR) rates (0%–60%). The results revealed that for all tested fuels as indicated mean effective pressure (IMEP) increased, particulate matter emissions first decreased and then increased. Compared to diesel under low load condition (IMEP = 3bar), the blending of butanol isomers had limited effect on particulate matter emissions. Among them, t-butanol increased the peak of particulate size distribution. When the engine load is higher than IMEP of 6 bar, the blending of butanol isomer significantly improved the particulate matter emissions. For IMEP fixed at 8bar, increasing the EGR rate made the particulate matter increase, especially for direct injection diesel. Butanol isomer/diesel blends can achieve low NOx and significantly improves particulate matter emissions in low temperature combustion mode (EGR = 60%). When EGR rates higher than 30%, the butanol isomer/diesel blends had a much smaller GMD than neat diesel. A comprehensive investigation of the four butanol isomer/diesel blends showed that t-butanol always had the highest particles than other butanol isomers under different EGR rates.

Electric vehicles have the feature of being quiet when running, thus may led to high potential risk of traffic accident between cars and pedestrians. To avoid pedestrian injuries, many country tends to force auto manufacturers to equip their cars an acoustic vehicle alerting system for indication purpose. This paper intend to give a brief introduction of related standards and regulations developed or underway, deliver comprehensive comparison in technical aspects, and finally offers a broad view of the state of art of this realm.