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Biodiesel combustion particulate matter (PM) is different from diesel combustion PM in terms of microscopic morphology, which directly affects the optical properties of PM. To investigate the effect of the microstructure of biodiesel PM on the extinction characteristics, an experiment was performed on a high-pressure common rail diesel engine to collect PM from three kinds of biodiesel (the main raw materials were soybean oil methyl eater (SME), palm oil methyl eater (PME), and waste cooking oil methyl eater (WME), respectively). The particle size distribution, micro morphology, and extinction characteristics of biodiesel PM were analyzed. Results show that combustion biodiesel reduces PM emissions by up to 84.2%. Compared to PM from diesel, biodiesel PM has a smaller particle size and a higher aggregation degree, which results in weaker light absorption capacity. With the iodine number of biodiesel decreasing, the number concentration of biodiesel PM decreases and the fractal dimension increases, which leads to producing a more complex agglomerate and a consequent reduction in extinction coefficient. The average particle sizes of PM from SME, PME, and WME are 5.1%, 6.7%, and 13.9% lower than that of diesel PM. Compared with diesel combustion PM, the peak absorption coefficients of SME, WME, and PME combustion PM decrease by 8.4%, 11.4%, and 13.3%, respectively. The extinction properties of particles decrease with increasing fractal dimension within the wavelength range of visible light.

In order to further improve the power and fuel economy of hybrid vehicles, this paper proposes a method of hybrid vehicle powertrain matching by combining orthogonal tests with Cruise software, supplemented by the control strategy formulation of critical components of the whole vehicle on the MATLAB/Simulink platform. Considering the influence of vehicle engine, electric motor, battery and overall mass on the powertrain design, the L9(34)-type orthogonal table is selected for the orthogonal test design. After verifying the feasibility and accuracy of each design solution of the powertrain, the different design solutions are simulated for power and economic performance. Finally, the best performance indicators of the vehicle are as follows: the maximum speed is 183.35 km/h, the 0–100 km/h acceleration time is 6.87 s, and the maximum degree of climbing is 39.65 percent. The fuel consumption of 100 km is 3.47 L. The optimal solution was compared with the third-generation Harvard H6 and AITO M5 in terms of fuel saving and emission reduction, and it was found that for every 15,000 km driven, it is expected to save 469.5 L of fuel and 109.5 L of CO2, respectively, which can reduce fuel use and emission by about 1051.21 kg and 245.17 kg CO2, respectively. This simulation experiment can reduce the workload of traditional power system matching. It can provide ideas for power system matching and optimization for Corun CHS Technology Co., Ltd. (Foshan City, Guangdong Province, China) and offer a certain degree of reference for hybrid vehicle power system design and simulation.

Battery electric vehicles (BEVs) are one of the most promising new energy models for industrialization and marketization at this stage, which is an important way to solve the current urban haze air pollution, high fuel cost and sustainable development of the automobile industry. This paper takes pure electric buses as the research object and relies on the operation information management platform of new energy buses in Nantong city to propose an electric bus cycle construction method based on the mixed interpolation method to process sparse data. Three different interpolation methods, linear interpolation, step interpolation and mixed interpolation, were used to preprocess the collected data. The principal component analysis method and K-means clustering algorithm were used to reduce and classify the eigen parameter matrix. According to the clustering results, different categories of moving section and idle section libraries were established. According to the length of time and the correlation among various types, several moving sections and idle sections were selected to form a representative driving cycle of Nantong city buses. The results show that the mixed interpolation method, based on linear interpolation and cubic spline interpolation, has a good processing effect. The average relative error between the synthesized working conditions and the measured data are 15.71%, and the relative error of the seven characteristic parameters is less than 10%, which meets the development requirements. In addition, the comparison and analysis with the characteristic parameters of the world typical cycle conditions (NEDC, WLTC) show that the constructed cycle conditions of Nantong city are reasonable and reliable to represent the driving conditions of pure electric buses in Nantong city, which can provide a reference for the optimization of the bus energy control strategy.

In this study, two shale samples with different maturities, from Geniai, Lithuania (Ro = 0.7%), and Wenjiaba, China (Ro = 2.7%), were selected for open-system pyrolysis experiments at 400 °C and 500 °C, respectively. The generation of isotopic gases from the shales with different maturities was investigated, and the effects of pyrite catalysis on the carbon isotopic compositions were also studied. It was found that CO2, CH4 and their isotopic gases were the main gaseous products of the pyrolysis of both shales, and more hydrocarbon gases were generated from the low-maturity Geniai shale. The δ13C1 values fluctuated from −40‰ to −38‰, and δ13C2 showed higher values (−38‰~−34‰) for the Geniai shale. In addition, its δ13CCO2 values ranged from −28‰ to −26‰. Compared with the Geniai shale, lower δ13C1 values (−43‰~−42‰) and higher δ13CCO2 values (−19‰~−14‰) were detected for the Wenjiaba shale. As temperature increased, CH4 became isotopically lighter and C2H6 became isotopically heavier, which changes were due to the mass-induced different reaction rates of 12C and 13C radicals. Furthermore, the pyrite made the kinetic isotope effect stronger and thus made the CH4 isotopically lighter for both shales, especially at the lower temperature of 400 °C.

This paper studies the influence of carbonaceous components on the optical properties of particulate matter (PM) in biodiesel combustion by conducting a bench test on an electronically controlled high-pressure common-rail diesel engine. In addition, the PM produced by the combustion of diesel oil, soybean oil methyl ester (SME), waste edible oil methyl ester (WME), and palm oil methyl ester (PME) was collected. The carbonaceous composition and optical properties of diesel and three biodiesel particulates were then analyzed. The obtained results showed that the ratio of organic carbon (OC) to total carbon (TC) in diesel PM was 0.25 and the ratio of OC/EC was 0.33. The OC to TC ratio of biodiesel PM was significantly greater than that of diesel PM, ranging between 0.59 and 0.65, with OC/EC values in the range of 1.44-1.86. The mass absorption cross-section (MAC) values of three kinds of biodiesel particles were all higher than those of diesel particles. When the incident laser wavelength increased, the difference of MAC values among four kinds of fuel particles gradually decreased. The MAC values of all the three biodiesel particles were higher than those of the diesel particles, and the difference between the MAC values of the four fuel particles gradually decreased with the increase of the incident laser wavelength. Afterwards, the "shell-core" model of particles was developed with 80 nm EC sphere as the core. At the two refractive indices, the scattering cross section, absorption cross section, and extinction cross section of the particles decrease with the increase of the incident light wavelength, and the scattering cross section, absorption cross section, and extinction cross section of the particles increase with the increase of the OC coating thickness.

Extraction of shale gas from shale reservoirs is significantly affected by shale wettability. Recently, thermal recovery technologies (e.g., combustion) have been tested for shale gas recovery. This requires an understanding of the wettability change mechanism for thermally treated shale samples. In this study, the effect of combustion on shale wettability was investigated. Shale samples were first processed to obtain smooth surfaces and then combusted at temperatures of 200, 400, and 800 °C. The initial contact angles and dynamic behavior of water droplets on shale surfaces were recorded using the sessile drop method. It was found that pores and fractures were generated on the shale surfaces following high-temperature combustion. The pore volume and diameter increased with increasing combustion temperature, which improved the connectivity of hydrophilic pore networks. Compared to a raw shale sample, the shale sample combusted at 400 °C showed a smaller initial water contact angle and a more rapid decrease in the contact angle because of the oxidation of organic matter and generation of pore structures. Water droplets were found to completely spread over the surface of the shale sample combusted at 800 °C because of the generation of fractures. Moreover, the van der Waals potential between water droplets and combusted shale samples was determined to be stronger. However, the initial contact angle and dynamic behavior of water droplets did not show a significant change for the shale sample combusted at 200 °C. As a result, high-temperature combustion (≥400 °C) can be used to significantly improve the hydrophilicity of shale.

This study aims to reveal the evolutionary process of particles during the diesel exhaust transport process and to further understand the effects of diesel exhaust transport distance (DET) on a particulate microstructure. Specifically, the micromorphological, particle size distribution, and aggregate characteristics of particles as well as the variation of the structural characteristics of elementary carbon particles (ECPs) as DET changed were examined using an engine exhaust particle size spectrometer, a high-resolution transmission electron microscopy system, and a small-angle X-ray scattering system. The results show the following: As DET increased, the chains gradually lengthened, the extent of accumulation and stacking increased, and a number of clusters gradually rose. The average particle diameter increased from 23.1 nm at 0 m to 92.7 nm at 3 m. In addition, as DET increased, the number of accumulation-mode particles, the number of folded, curved carbon layers in the inner core of carbon particles, and the disorderliness of carbon layers in the outer shell of carbon particles all increased. Moreover, the boundary between the inner core and the outer shell became increasingly obscure. As DET increased, there was a gradual decrease in the difference in electron density between particles, and the fractal dimensionality of the distribution, average cross-sectional size, radius of gyration, and axial length of pores were, respectively, 33.3%, 40%, 38.2%, and 50.3% less at 3 m than at 0 m. Besides that, the number of small ( 10 nm) pores gradually decreased. Overall, as DET increased, pore size and number decreased. There was a gradual increase in the number of folded and curved carbon layers in the inner core of ECPs and an increase in the disorderliness of carbon layers in their outer shell as DET increased. Furthermore, the boundary between the inner core and the outer shell became increasingly obscure as DET increased. The crystallite size of ECPs decreased from 1.365 nm at 0 m to 1.098 nm at 3 m. This suggests that the number of continuously arranged carbon atoms decreased, the arrangement of carbon atoms was more disorderly, and the degree of graphitization decreased. As DET increased, there was a gradual increase in the interlayer spacing and curvature of ECPs. This suggests that increasing DET led to a more disorderly distribution of electron orbitals inside the carbon layers, less electron resonance stability in the carbon layers, greater oxidative activity of ECPs, and greater inherent oxidative capacity of particles.

Appropriate amount of methyl myristate (C14), methyl palmitate (C16), methyl stearate (C18), methyl oleate (C18:1), methyl linoleate (C18:2), and methyl ricinoleate (C18:1OH) were blended into low-...

Recently, thermal recovery technologies such as combustion have been studied for shale gas recovery. Thus, understanding of the microstructure of combusted shale is essential for evaluating the effects of thermal treatment on shale gas transport capacity. In this study, the effect of combustion on shale microstructure changes was investigated. Firstly, different-sized shale samples were combusted at 450 °C for 30 min. Afterward, shale microstructure properties including surface topographies, porosity and permeability of the raw and combusted shale samples were measured and compared. It was found that the pore volume and specific surface area increased after combustion, especially for small pulverized samples. According to surface topography obtained from atomic force microscope, more rough surfaces were obtained for the combusted shale due to larger pores and generation of thermal fractures caused by the removal of organic matter. Based on the mercury intrusion porosimetry measurements, the porosity of the shale samples increased from 2.79% to 5.32% after combustion. In addition, the permeability was greatly improved from 0.0019 to 0.6759 mD, with the effective tortuosity decreased from 1075.40 to 49.27. As a result, combustion treatment can significantly improve the gas transport capacity.

Extracting coalbed methane is challenging due to the strong gas adsorption capacity and low matrix permeability of the coalbed. Recently, thermal recovery methods have been tested to promote methane recovery. In this study, anthracite samples were heated to different temperatures to investigate the internal pressure variation and microstructure changes. It was found that higher temperature resulted in higher internal pressure. At low temperatures, the increase in the internal pressure was mainly due to gas desorption. At 500°C, thermal cracking gases provided the main contribution to the high internal pressures, as more gaseous products were generated at the higher temperature. In addition, the microstructure of coal significantly changed after combustion, including the increased pore volume, the increased specific surface area, and the generation of microfractures. These changes could potentially increase the porosity and permeability of coal. Thus, high‐temperature thermal treatments not only provided energy for gas desorption and organic matter decomposition but also improved conditions for gas transport.

The effects of EGR on the carbon-containing functional groups in PM were determined by X-ray absorption near-edge spectroscopy. A TG analyzer was used to determine the effects of EGR on the components and oxidative activity of PM. The results show that the use of EGR in the diesel engine had a minor influence on the types of carbon-containing functional groups in the PM; however, it did affect their relative contents. As the EGR rate increased, the aromatic and graphitized carbon contents of the PM gradually decreased, and the contents of the oxygen-containing and aliphatic C H functional groups increased, which strongly promoted the oxidative activity of the PM. The percentage of soot in the PM decreased with the use of EGR, while the percentages of water and volatile organic matter increased. In addition, the volatile emission temperature TSOF1 gradually decreased, and the trends in the initial volatile combustion temperature TSOF2, the soot ignition temperature Ti, and the burnout temperature Th were consistent with that in the volatile emission temperature. Both the combustion and burnout characteristic indices gradually increased as the EGR rate grows. Instead, the activation energy decreased dramatically, and the energy required for PM to react decreased with the increase of EGR rate.

To investigate the effect of diesel fuel and different fatty acid methyl esters (FAMEs) biodiesels on the pore structure and oxidation activity of exhaust soot, an experiment was performed on a 4-cylinder high-pressure common-rail diesel engine fueled with commercial diesel fuel and three types of biodiesels (used soybean oil methyl eater (SME), palm oil methyl eater (PME), and waste cooking oil methyl eater (WME) as the main resources, respectively). Results showed that four kinds of exhaust soot had similar porous morphology, while the C/O ratio of biodiesel soot was lower than diesel soot. The N2 adsorption of four kinds of soot belonged to the multi-layer adsorption of mesopore or macropore media, and the N2 adsorption capacity of biodiesel soot was more substantial than that of diesel soot. The specific surface area, the pore volume, and the fractal dimension of three biodiesel soot were larger than that of diesel soot, and the mean pore size was smaller, which meant that the porosity of biodiesel soot was higher than that of diesel soot, and it had a rougher surface. Biodiesel particles contained more aliphatic C–H surface functional groups (SFGs), which may be related to the adsorption of more soluble organic fractions (SOF) by soot surface. A larger surface area and a higher porosity of biodiesel soot also improved the reactivity of soot. The iodine number and oxygen content of biodiesel had a significant effect on the pore structure and oxidation activity of soot. The low iodine number and high oxygen content of biodiesel (mainly consist of WME) helps to reduce PM emissions and improve the porosity and oxidation activity of biodiesel soot.

This study aims to reveal the evolutionary process of particles during the diesel exhaust transport process and to further understand the effects of diesel exhaust transport distance (D

Via partial hydrogenation, polyunsaturated fatty acid methyl esters (FAMEs) in biodiesel were largely converted to monounsaturated and saturated FAMEs, which brought the following changes i...

The nano-fuel are prepared by dispersing CNT, CeO2, and Co3O4 nanoparticles in n-tetradecane (C14). This experimental study investigates the effect of nanoparticles mass fraction as well as the var...

Silicon is one of the most promising anode candidates for the next generation Li-ion batteries. Polymer binders play a crucial role as they are very essential to keep mechanical integrity of the electrodes and affect the solid electrolyte interphase (SEI) properties. Alginate appears to be the best binder system for Si electrode and it is able to form three-dimensional (3D) conductive polymeric network through in-situ inter-chain cross-linking by divalent cations. Herein, the effects of different cross-linking cations (Cu2+, Ca2+, Fe2+ and Ni2+) on the electrochemical behavior of silicon nano-sized particle anodes with alginate binder are investigated. It is found that all the alginate networks bridged by the transition metal cations are able to tolerate the volume change of silicon and effectively restrict the volume expansion of the Si particles. The overall electrochemical properties of the Si anode with Ni cations cross-linked alginate exhibit the highest reversible capacity, extraordinary cycleability and superior rate capability. The main reason for the electrochemical enhancement is explained by the improved stability of SEI film on the Si surface.

How to improve interface stabilization of silicon/silicon oxide anodes during the lithiation and delithiation process is a big challenge to promote their commercial utilization. In this work, a novel electrolyte additive of mesylethyl-methyl-pyrrolidinium (MEMP-DFOB) is reported, which helps to generate a beneficial film on the surface of silicon oxide-graphite (SiO/Gr) anode. Differential capacity vs. voltage (dQ/dV) results show that the film is formed at ~1.4 V. As a result, SiO/Gr anode based pouch full cells not only demonstrate enhanced discharge performance and cycling stability at −20 °C, but effectively inhibit gas releasing at high temperature of 45 and 60 °C, and successfully run over 900 cycles with a capacity retention of ~75 % at 45 °C. This strategy highlights a new way to develop SiO/Gr anode based lithium-ion batteries with outstanding performances at low and high temperature.

The partially hydrogenated soybean methyl ester (PHSME) is produced from soybean methyl ester (SME) via catalytic transfer hydrogenation. It is revealed that after the catalytic transfer hydrogenat...

For the hybrid electric vehicle (HEV), accurate prediction of the remaining use life for the power batteries under actual operating conditions is of great significance to the battery power state of charge (SOC) estimation, as well as to the reliability and safety. However, there is little study available to evaluate the battery degradation behavior in real applications. Current battery degradation model is mostly established based on laboratory condition. In such case, charging/discharging scenarios are mostly constant across the battery cycle, and thus, they may be not a good representative of the working condition of the Ni-MH in real application where charging/discharging are frequently altered. Therefore, in this paper, the cycle life degradation characteristics of Ni-MH batteries for HEVs were studied, and an experienced model of cycle life is established based on the data from the real-world driving settings. The cycle life results indicated that the capacity loss is strongly impacted by the charge and discharge rate (C-rate), temperature, and depth of discharge (DOD). A large cycle test matrix is used to collect battery life data to build the model. The test matrix parameters include temperature (25 °C, 45 °C, 55 °C), DOD (0.5, 0.8, 1) and C-rate (1C, 2C, 5C). To verify the reliability of the life model applied to the HEV, the equivalent cycle life test verification of the real vehicle road spectrum was carried out. The test results show that the model can characterize the battery's decay process well.

Aiming at an optimised single-mode compound power split hybrid system, the main operating mode of the hybrid system and the torque control strategy were developed in this paper. LMS/AMESim was used...

This study carries a comprehensive investigation on the influences of the key environmental and operating parameters on SOC and cycling life of the Ni-MH battery. The Ni-MH cells were tested through loading the actual road spectrum at different temperatures (25/35/45°C). Other parameters of SOC fluctuation and currents are set to be 10% and 15.5A by average, respectively. Tests have been performed to obtain the OCV (open circuit voltage)~SOC curves at different temperatures under the 1-C rate of charging/discharging. The investigation results show that the capacity decay compared to initial capacity is increased by a slight 2.46% at 45°C, demonstrating an excellent cycling performance of the Ni-MH battery. Additionally, the battery polarization effect is found to be correlated to the charging and discharging processes and temperature. In summary, this study presents a comprehensive factor analysis needed to achieve a reliable SOC estimate for the Ni-MH based HEV.

Biodiesel is mainly composed of methyl palmitate (MeC16), methyl stearate (MeC18), and methyl oleate (MeC18:1). In order to explore the crystallization behavior of biodiesel, the thermal parameters of the three fatty acid methyl esters, their binary mixtures, and biodiesel have been analyzed based on the differential scanning calorimeter. Supposing that biodiesel is a complex solution of various fatty acid methyl esters, the saturated fatty acid methyl esters MeC16 and MeC18 are treated as solutes and the unsaturated fatty acid methyl ester MeC18:1 is served as the solvent; thus a thermodynamic model according to the solid–liquid equilibria for predicting the crystallization onset temperature has been established. As a result, the model is effectively verified when the estimated crystallization onset temperatures for four types of actual biodiesel are compared with the experimental results.

The V2O5 catalysts which supported on nano-scale TiO2 with variation of vanadium contents (5%, 10%, 20% and 40%) were prepared by an incipient-wetness impregnation method. The phase structures of nano-scale V2O5/TiO2 catalysts with different loading rates were characterized by Scanning electron microscope (SEM), X-Ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectra. The oxidation activities of catalysts over diesel soot were performed in a themogravimetric analysis (TGA) system. The kinetics of the catalytic oxidation process were analyzed based on Flynn-Wall-Ozawa method. The characterization results showed that the phase structure of V2O5 supported on TiO2 depends heavily on the vanadium contents, which will put great effects on the catalytic performances for soot oxidation. At a low vanadium loading rates (V5-V20), active species exist as monomers and polymeric states. At a high loading rate (V40), the crystalline bulk V2O5 covers the surface of TiO2. The formed crystal structure occupied the active sites and led a decreasing in the catalytic effect. By comparing the characteristics temperatures of soot oxidation over V2O5 catalysts, the catalytic activities of catalysts with different loading rates for soot oxidation can be ranked as: V5 < V10 < V40 < V20. Via pyrolysis kinetics analysis, it is revealed that the activation energy of soot oxidation is minimum when the vanadium loading rates is 20%, which is fit well with the TG experimental results. The consistency of pyrolysis kinetics and TG experimental results confirm that the best activity catalyst is V20 in discussed catalysts of this paper, which is nearest to the monolayer dispersion saturated state of V2O5/TiO2 catalyst. Moreover, it convincingly demonstrate the obvious threshold effect in V2O5 catalysts. Copyright © 2016 BCREC GROUP. All rights reservedReceived: 25th October 2015; Revised: 25th December 2015; Accepted: 5th January 2016How to Cite: Mei, D., Li, L., Zhu, C., Zhao, X., Yuan, Y. (2016). Phy-chemical Attributes of Nano-scale V2O5/TiO2 Catalyst and Its’ Effect on Soot Oxidation. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2): 161-169 (doi:10.9767/bcrec.11.2.542.161-169)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.542.161-169

Palm methyl ester (PME) was prepared from palm oil through transesterification using NaOH as catalyst. Chemical composition of the PME and -10 petrodiesel (-10PD) was determined by gas chromatography-mass spectrometer (GC-MS). The PME and -10PD were characterized for their fuel properties including density, kinematic viscosity, and flash point, cold filter plugging point, sulfur content, copper strip corrosion and oxidative stability. Volatility was measured by thermogravimetric analysis (TGA). Volatile index was proposed to describe PME/-10PD volatility. A good correlation model was put forward for calculating the PME/-10PD volatility by PME blending ratio. The study showed that PME was mainly composed of long chain fatty acid methyl esters (FAMEs): C14:0－C24:0, C16:1－C22:1, C18:2 and C18:3. -10PD was mainly composed of long chain alkanes: C8－C26. The fuel properties of PME were within the limits prescribed in the GB/T 20828-2007 standards for biodiesel. With respect to -10PD, volatilization of PME was stronger and quicker, but volatilization onset at higher temperature. The volatilization onset temperatures of PME and -10PD were 448.9 and 361.7 K respectively; and the volatile indexes were 1.76E-04 and 3.64E-05 respectively. The PME/-10PD volatility had relation to PME blending ratio. The volatility of B0－B20 was very close to the -10PD. The volatility of B20－B100 was better with increasing the PME blending ratio.

The Cottonseed oil methyl ester (COME) was prepared using an alkali catalyzed trans esterification reaction, and its chemical composition and cold flow properties (CFP) were studied. Two approaches, viz. blending with petrodiesel and treating with cold flow improver (CFI) were used to improve the CFP of COME. The results showed that COME was mainly composed of fatty acid methyl esters (FAMEs): C14:0–C22:0, C16:1–C20:1, C18:2 and C18:3–C20:3. The mass fractions of saturated and unsaturated FAMEs were 27.69% and 71.65%, respectively. The cold filter plugging point (CFPP) and kinematic viscosity (KV) at 40 °C of COME are -1 °C and 4.63 mm2/s respectively. Blending with -10 petrodiesel (-10PD) and 0 petrodiesel (0PD) can decrease the CFPP of COME/-10PD (B30-B40) and COME/0PD (B40-B50) -12 and -8 °C respectively. With the increase in petrodiesel content, the KV at 40 °C of blending oil decreased, and viscosity-temperature characteristics of blending oil were improved. When used Flow Fit (≤3vol.%), the CFPPs were reduce from COME/-10PD B5, B7, B10, B20, B50 and COME -8, -8, -9, -11, -11 and -1 °C to -28, -27, -26, -25, -16 and -5 °C respectively; COME/0PD -3, -3, -4, -5, -8 and -1 °C to -26, -25, -24, -24, -16 and -5 °C respectively.

High power cylindrical Ni-MH battery cells have a heavy heat load because of their high discharge rate and large equivalent internal resistance. This heavy heat load, together with an imbalanced flow in parallel liquid cooling systems, can lead to variances in the temperature of each cell in the entire battery pack, thereby reducing the life cycle of the battery pack. In this paper, a parallel-series combined liquid cooling system for a 288V Ni-MH battery pack was designed, and several parameters that influence the flow balance of the system by heat transfer and fluid dynamics were calculated. Then, a thermal-fluid simulation was executed with different parameters using StarCCM+ software, and the simulation results were validated by a battery pack temperature experiment on a bench and in a vehicle. The results indicate that the cell&rsquo, s temperature and temperature differences can be kept within an ideal range. We also determined that within the battery power requirements and structural spacing limits, the total flow rate of the cooling liquid, the cross-sectional area ratio of the main pipe to the branch pipes, and the number of internal supporting walls in each branch pipe need to be large enough to minimize the cell&rsquo, s maximum temperature and temperature differences.

One of the most important challenges in engine applications is to reduce emissions. Improving fuel quality by adding nanoparticles is an appropriate method to meet this challenge. In the study, two typical nanometre materials, i.e., CNT (which is non-metallic and possesses excellent thermal conductivity) and nano-MoO3 (which represents the metal oxides and owns favourable catalytic function), were examined comparatively as additives in neat diesel. CNT-diesel and MoO3-diesel nano-fuels were prepared using the appropriate physical and chemical dispersion methods. Experiments were performed in a single-cylinder common rail diesel engine to investigate and compare the combustion and emissions performances of nano-fuels with neat diesel. It was found that both CNT-diesel and MoO3-diesel achieved better performance in fuel economy, combustion and emissions than neat diesel. These outcomes may be due to the excellent thermal conductivity and surface deficits of CNT and the good catalytic oxidation function of MoO3. In addition, CNT-diesel was found more promising, because it seems to produce more benefits in promoting combustion efficiency and emissions reduction than MoO3-diesel.

Power electronic transformer (PET) is being widely used in place of line frequency transformer (LFT) in modern power systems. For PETs' circuit in high-power and high-voltage applications, cascaded H-bridge or modular multilevel converter is preferred due to the advantages of modular structure. For such topologies, the low-frequency ripple powers stored in dc-link capacitors pose passive effects on power density. In this paper, a power channel based power electronic transformer (PC-PET) as well as power decoupling control is proposed for three-phase AC - DC conversion. Based on cascaded architecture, the ripple powers introduced by each AC input are counteracted without flowing into dc link. Therefore the dc capacitance can be reduced so as to achieve higher power density and lower cost. Simulation results prove the validity of proposed topology and decoupling control strategy. It is expected to be applied in the interconnection of three-phase AC and DC grid as smart energy router.

External morphology and internal carbonaceous compositions are important characteristics for the source recognition of atmospheric particulate matter (PM). The fractal dimension of morphology and carbon components of diesel PM with different sizes both at high and low load were studied through fractal theory and thermal optical reflection method. It is revealed that small-size PM absorbs more soluble organic fractions and correspondingly has greater box dimension. Due to heavy aggregation, PM collected at low load has greater box dimension than that at high load because of heavy aggregation. OC1, which is the most volatile among organic carbons, is remarkably increased at low load or for small-size PM, absorbing more unburned hydrocarbons. At low load, a large amount of EC1 (char-EC) is generated and the ratio of OC/EC is more than 10, while, at high load, the EC is mainly composed of EC2 (soot-EC) and the ratio of OC/EC is less than 1. Apparently, the box dimension from the morphology of diesel PM presents a positive correlation with the ratio of OC/EC. Via above external and internal characteristics, particulates exhausted from motor vehicles in the atmosphere can be beneficially identified.