Co_(3)O_(4)as an efficient passive NO_(x) adsorber for emission control during cold-start of diesel engines

The Co_(3)O_(4)nanoparticles,dominated by a catalytically active(110)lattice plane,were synthesized as a low-temperature NO_(x) adsorbent to control the cold start emissions from vehicles.These nanoparticles boast a substantial quantity of active chemisorbed oxygen and lattice oxygen,which exhibited a NO_(x) uptake capacity commensurate with Pd/SSZ-13 at 100℃.The primary NO_(x) release temperature falls within a temperature range of 200-350℃,making it perfectly suitable for diesel engines.The characterization results demonstrate that chemisorbed oxygen facilitate nitro/nitrites intermediates formation,contributing to the NO_(x) storage at 100℃,while the nitrites begin to decompose within the 150-200℃range.Fortunately,lattice oxygen likely becomes involved in the activation of nitrites into more stable nitrate within this particular temperature range.The concurrent processes of nitrites decomposition and its conversion to nitrates results in a minimal NO_(x) release between the temperatures of 150-200℃.The nitrate formed via lattice oxygen mainly induces the NO_(x) to be released as NO_(2) within a temperature range of 200-350℃,which is advantageous in enhancing the NO_(x) activity of downstream NH_(3)-SCR catalysts,by boosting the fast SCR reaction pathway.Thanks to its low cost,considerable NO_(x) absorption capacity,and optimal release temperature,Co_(3)O_(4)demonstrates potential as an effective material for passive NO_(x) adsorber applications.

Analysis of Emissions Profiles of Hydraulic Fracturing Engine Technologies

Today, the oil and gas industry, and in particular hydraulic fracturing operations, have come under increasing pressure from regulators and the public to reduce emissions. As the industry evolves, oil and gas producers are in the position of evaluating alternative technologies which will support their objectives of reducing their overall emissions profile and carbon footprint. As a response, the deployment of technology and solutions to reduce emissions related to hydraulic fracturing applications has recently accelerated, creating various options to address these industry challenges. BJ Energy Solutions and West Virginia University have been working on the application and emissions characterization of various hydraulic fracturing technologies. A study was conducted to evaluate the efficiency and resultant emissions from various technologies, including natural gas reciprocating engines, diesel-natural gas dual-fuel engines, large (>24 MW) gas turbines, and direct drive turbines. The study involved the development of an emissions model with the purpose of estimating total emissions of carbon dioxide (CO2), nitrous oxide (N2O) and exhaust methane (CH4) slip, all Greenhouse Gases (GHGs), and converted to tons of CO2 equivalent emissions per day of operation. The model inputs are the required Hydraulic Horsepower (HHP) based on pumping rate and pressure for various shale play scenarios. The model calculates emissions from the TITAN, which is a direct-drive turbine model fielded by BJ, using data collected following U.S. Environmental Protection Agency (EPA) testing protocols. The model also calculates and compares other hydraulic fracturing technologies utilizing published Original Equipment Manufacturer (OEM) data. Relevant EPA-regulated criteria emissions of oxides of nitrogen (NOx), Carbon Monoxide (CO) and Particulate Matter (PM) are also reported. Modeling results demonstrated that in most cases, the TITAN gas turbine system has lower total GHG emissions than conventional diesel and other next-generation technologies, and also has lower criteria emissions. The benefits of the TITAN gas turbine system compared to the other technologies stems from significantly lower methane slip, and the high-power transfer efficiency resulting from directly connecting a turbine to a reciprocating pump, despite the comparatively lower thermal efficiency.

Effect of Palm Oil Biodiesel Blends on Engine Emission and Performance Characteristics in an Internal Combustion Engine

Increasing global environmental issues and depleting fossil fuel reserves has necessitated the need for alternative and sustainable fuel. In this paper, the effects of biodiesel and its blend on engine emission and performance characteristics in an internal combustion engine were analyzed. Biodiesel derived from the transesterification of raw palm oil was blended with diesel fuel at different proportions designated as PO5 (5% Biodiesel and 95% Diesel), PO10 (10% Biodiesel and 90% Diesel), PO15 (15% Biodiesel and 85% Diesel), PO20 (20% Biodiesel and 80% Diesel), PO50 (50% Biodiesel and 50% Diesel), PO85 (85% Biodiesel and 15% Diesel), and PO100 (100% Biodiesel). A Lombardini 2-cylinder, four-stroke direct injection diesel engine with a compression ratio of 22.8 was developed using Ricardo Wave software in which diesel, palm oil biodiesel blends and pure biodiesel are used in the model, and the obtained results were analysed and presented. The simulation was done under varying engine speeds of 1200 rpm to 3200 rpm at full load condition. Biodiesel and its blends are more environment-friendly and non-toxic when compared to diesel fuel;it also improves the mechanical efficiency of the engines, and above all can also lead to a reduction in poverty among rural dwellers. The obtained results showed that brake specific fuel consumption and brake thermal efficiency increased with palm oil biodiesel blends as compared to diesel fuel which might be a result of biodiesel’s lower heating value, and the increase in thermal energy may be a result of the oxygenation of the biodiesel blend as compared to pure diesel. In terms of brake torque, palm oil biodiesel blends were lesser than diesel fuel. The CO, HC, and NOx emissions of palm oil biodiesel blends decreased significantly compared to that of pure diesel. From this study, palm oil biodiesel emits lesser emissions than diesel fuel and its performance characteristics are similar to diesel fuel. Therefore, palm oil biodiesel can be used without any modifications directly in a diesel engine. In addition, it can also be used as blends as an alternative and sustainable fuel, decreasing air pollution, and increasing environmental sustainability.

COMPOSITIVE EMISSION CONTROL SYSTEM OF GASOLINE VEHICLE

The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation （EGR）, thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite （S.I.） engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.

Control Engineering of China Special Issue on "Control Systems Engineering"

Control systems contribute to every aspect of modem society.In our life control systems exist in almost everywhere such as toasters,VCRs and smart phones.In science and technology,control systems already have widespread applications,for example,steering ships,guiding missiles and driving driverless cars in the near future.In all the control systems,systems are the key platform where control should be put into.It is at the system level that control shows its values.Extracting and formulating

Analysis of the Emissions and Performance of a Diesel Engine Using Pumpkin Seed Oil Methyl Ester with Different Injection Pressures

Biodiesel fuel is a potential alternative energy source for diesel engines due to its physiochemical characteristics relatively similar to those of traditional diesel fuel.In this study,the performance,emission,and combustion features of a mono cylinder DI diesel engine are assessed using 20%Pumpkin seed methyl ester(PSOME20)and considering varying injection pressures(200,220,240,and 260 bar).The considered Pumpkin seed oil is converted into pumpkin biodiesel by transesterification and then used as fuel.The findings demonstrate that the Brake Thermal Efficiency(BTE)of PSOME20 can be raised by 1.68%,and the carbon monoxide(CO),hydrocarbon(HC),and smoke emanations can be lowered,while oxides of nitrogen(NOx)emissions are increased at an injection pressure(IP)of 240 bar compared to the standard IP of 200 bar.The cylinder pressure and the Heat Release Rate(HRR)become higher at 240 bar,whereas the ignition delay is shortened with respect to PSOME20 at a normal IP of 200 bar.

Novel Oxygen Storage Components Promoted Palladium Catalysts for Emission Control in Natural Gas Powered Engines

A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted in improved activities of the fresh and aged catalyst by lowering the light-off temperature for methane in natural gas engines exhaust.

使用《Linear Control Systems Engineering》的实践

本文介绍了使用原版教材《L inear Con trol Systems Engineering》、英语授课的教学实践及改革措施 ,提出了进一步的实施计划。

Combining artificial neural network and multi-objective optimization to reduce a heavy-duty diesel engine emissions and fuel consumption

Nondominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ) is well known for engine optimization problem. Artificial neural networks(ANNs) followed by multi-objective optimization including a NSGA-Ⅱ and strength pareto evolutionary algorithm(SPEA2) were used to optimize the operating parameters of a compression ignition(CI) heavy-duty diesel engine. First, a multi-layer perception(MLP) network was used for the ANN modeling and the back propagation algorithm was utilized as training algorithm. Then, two different multi-objective evolutionary algorithms were implemented to determine the optimal engine parameters. The objective of the present study is to decide which algorithm is preferable in terms of performance in engine emission and fuel consumption optimization problem.

Emission and performance analysis of a diesel engine burning cashew nut shell oil bio diesel mixed with hexanol

In this study, the effect of doping hexanol into biodiesel which is from neat cashew nut shell biodiesel oil on the emissions and the performance characteristics was studied in a constant speed diesel engine. The main purpose of this work is to reduce various emissions and also to improve the performance of the diesel engine when fueled with blends of hexanol and neat cashew nut shell biodiesel. Cashew nut shell oil is not edible, and hence it can be used as a viable alternative to diesel.Cashew nut shell biodiesel is prepared by conventional transesterification. Hexanol with 99.2% purity was employed as an oxygenated additive. Experimental studies were conducted by fueling diesel as a baseline and by fueling hexanol and neat cashew nut shell biodiesel mixture. A fuel comprising 10%（by volume） of hexanol and 90%（by volume） neat cashew nut shell biodiesel was referred to as CNSBD900 H100 and fuel comprising 20%（by volume） of hexanol and 80%（by volume）of neat cashew nut shell biodiesel was referred to as CNSBD800 H200. This study also investigated the possibility of using pure biofuel in an unmodified naturally aspirated diesel engine. The outcome of this study showed that adding hexanol at10% and 20%（by volume） to cashew nut shell biodiesel results in a reduction in emissions. In addition, a significant improvement in brake thermal efficiency and reduction in brake-specific fuel consumptions were achieved. Hence, it could be concluded that hexanol could be a viable and promising additive for improving the drawbacks of biodiesel when it was used to fuel an unmodified diesel engine.

Emission and performance study emulsi ed orange peel oil biodiesel in an aspirated research engine

This study paves the way on reducing smoke emission and NO_x emissions of research diesel engine by detailing the e ect of water addition in biodiesel. Fuel samples were prepared with di erent concentrations of water in orange peel oil biodiesel(94% waste orange peel oil biodiesel + 4% water + 2% Span 80(WOPOBDE1) and 90% waste orange peel oil biodiesel + 8% water + 2% Span 80(WOPOBDE2). Span 80 was employed as a nonionic surfactant, which emulsifies water in biodiesel. Experimental results revealed that the nitrogen oxides and smoke emission of orange peel oil biodiesel emulsion were reduced by 11%–19% and 3%–21%, respectively, compared to that of neat orange peel oil biodiesel(WOPOBD). In addition, the introduction of orange peel oil–water emulsions in the diesel engine considerably reduced the emissions of unburned hydrocarbons and carbon monoxide. The overall hydrocarbon emission of WOPOBDE2 was 12.2% lower than that of WOPOBD and 16.3% lower than that of diesel. The overall CO emission of WOPOBDE2 was 17% lower than that of base fuel(WOPOBD) and 21.8% lower than that of diesel. Experimental results revealed that modified fuel had higher brake thermal e ciency and lower brake specific fuel consumption than that of base fuel at all engine brake power levels.

Modeling the Effect of Variable Timing of the Exhaust Valves on SI Engine Emissions for Greener Vehicles

The problem with fixed valve timing that the valve train is set by the automaker for peak efficiency running at a specific point in the engine’s operating range. When the vehicle is moving slower or faster than this ideal operating point the engine’s combustion cycle fails to properly burn the air/fuel mixture leading to considerably compromised engine performance and wastes fuel. Variable Valve Timing (VVT) is a solution developed to overcome this engine deficiency, dynamically altering the valve's opening and closing for optimal performance at any speed. The intension in this work is to contribute towards pursuing the development of variable valve timing (VVT) for improving the engine performance. This investigation covers the effect of exhaust valve opening (EVO), and closing (EVC) angle on engine performance and emissions. The aim is to optimize engine power and brake specific fuel consumption (BSFC) where the effect of engine speed has also been considered. Power, BMEP, BSFC, NO, and CO were calculated and presented to show the effect of varying valve timing on them for all the valve timing cases. The calculations of engine performance were carried out using the simulation and analysis engineering software: LOTUS”, and engine emissions were calculated using “ZINOX” program. Sensitivity analysis shows that the reduction of 10% of (EVO) angle gave a reduction of around 2.5% in power and volumetric efficiency, also a slight increase in nitrogen oxide (NO) and carbon monoxide (CO), while a 10% decrease in (EVC) causes around 1% improvement in Power. The effects of different (VVT) from the simulations are analyzed and compared with those in the reviewed literature.

Research on Spray, Combustion and Emission Characteristics for DI Diesel Engine

To improve the combustion chamber shape that can decrease the directed injection （DI） diesel emission, the theories of DI diesel spray, combustion and pollutant formation model are analysed and implemented based on the CFD code FIRE. Results show that the chamber with contracting orifice can get stronger squish swirl intensity. The results of the verification studies show a good accordance with the measurements and reveal that the individual processes of spray, evolution, combustion and pollutant formation are well captured in FIRE. Finally, based on the analyzing and comparing of the calculation results of different chambers, a combustion chamber of contracting orifice geometry with lower emission is proposed.

Research and Development of Engine-Generator Set Control System for Tracked Vehicle Electric Transmission System

As an energy generating equipment, the engine-generator set supplies power to the electric transmission. Therefore, its control is one of the key technologies of electric vehicles. Based on the discussion about the demands to the engine-generator set in tracked vehicles, the detailed function of engine-generator and the control strategy are determined. The hardware and software of the control system are also developed and tested in a prototype vehicle. The experiment results show that the control system has good reliability and can satisfy the power requirements of vehicles under all operating conditions.

Engine Performance and Exhaust Emissions of Peanut Oil Biodiesel

The engine performance and exhaust emissions of biodiesel produced from peanut oil must be evaluated to assess its potential as an alternative diesel fuel. In this study, two diesel engines rated at 14.2 kW (small) and 60 kW (large) were operated on pure peanut oil biodiesel (PME) and its blends with a reference diesel (REFDIESEL). Results showed that comparable power and torque were delivered by both the small and large engines when ran on pure PME than on REFDIESEL while brake-specific fuel consumption (BSFC) was found to be higher in pure PME. Higher exhaust concentrations of nitrogen oxides (NOx), carbon dioxide (CO2) and total hydrocarbons (THC) and lower carbon monoxide (CO) emissions were observed in the small engine when using pure PME. Lower CO2, CO and THC emissions were obtained when running the large engine with pure PME. Blends with low PME percentage showed insignificant changes in both engine performance and exhaust emissions as compared with the reference diesel. Comparison with soybean biodiesel indicates similar engine performance. Thus, blends of PME with diesel may be used as a supplemental fuel for steady-state non-road diesel engines to take advantage of the lubricity of biodiesel as well as contributing to the goal of lowering the dependence to petroleum diesel.

Numerical Investigation of the Effects of Rate-Shaped Main Injection on Combustion and Emission in an OPOC Two-Stroke Diesel Engine

The effects of various split injection strategies on the opposed-piston opposed-cylinder(OPOC)diesel engine combustion and emission characteristics have been studied numerically using AVL-Fire CFD tools.The five rate-shaped main injections were used in split injection strategies.The results show that ignition delay from a rectangular injection rate is the shortest.Maximum pressure of the trapezoid injection rate is the largest.And the NOx emission of the rectangular injection rate is the largest.Meanwhile,the soot emission of the trapezoid injection rate is the least among the five injection rates.

Evaluation of Anthropogenic Air Emissions from Marine Engines in a Coastal Urban Airshed of Texas

Corpus Christi, Texas, is a growing urban area with a busy port and a petrochemical industrial base that is currently in compliance with the US Environmental Protection Agency’s (EPA) National Ambient Air Quality Standards (NAAQS) for ozone. However, the Texas Commission on Environmental Quality (TCEQ) has classified this urban airshed as a near non-attainment area. A comprehensive annual air emission inventory based on marine engines activity was developed for the years of 2006-2009 for the Port of Corpus Christi, Texas using recent EPA approved methodology. A regional-scale photochemical model Comprehensive Air Modeling system with extensions (CAMx) was used to evaluate the impact of these emissions on the ground level ozone concentrations by zeroing out the emissions and employing Direct Decoupled Method (DDM) for sensitivity analysis to estimate the 8-hour ozone sensitivity coefficients due to NOx and VOC emissions from marine engines. The analysis has shown a localized increase of up to 7.8 ppb in the 8-hour ozone concentration very close to the port premises and a decrease of about 1.73 ppb further downwind. Ozone sensitivity analysis using DDM on the 8-hour ozone concentrations showed a higher sensitivity to NOx emissions. Thus, any NOx related controls of marine engines will benefit local urban and regional ozone levels.

Experimental Study on the Performance and Emission of Chinese Small Agricultural Diesel Engine Fuelled with Methanol/Biodiesel/DTBP

Diesel engine alternative fuels, such as methanol and biodiesel, are beneficial to reduce diesel engine emission. In order to study the influence of methanol and biodiesel on the performance, economy and emission of small agricultural diesel engine, the physical-chemical properties(cetane number, lower heat value(LHV), viscosity, etc.) of methanol and biodiesel were analyzed. The methanol and biodiesel showed good complementary property to some extent. When a large proportion of methanol was added into biodiesel, the cetane number of the methanol/biodiesel blend will be greatly reduced. Since the cetane number of the blend fuel has great influence on the combustion process of diesel engine, after testing for blending ratio of methanol/biodiesel, the blend was prepared with 5%(BM5), 10%(BM10) and 15%(BM15) methanol, respectively. Di-Tert-Butyl Peroxide(DTBP) was chosen as a cetane number improver to be added into methanol/biodiesel blend. 0.25%, 0.50% and 0.75% of DTBP was added into BM15. The bench test was carried out on a 186 FA diesel engine to study the effect of methanol and DTBP on the engine performance and emissions. The results show that, at rated condition, compared with biodiesel, the NO;concentration of BM5, BM10 and BM15 is reduced by 5.02%, 33.85% and 21.24%, and smoke is reduced by 5.56%, 22.22% and 55.56%. However, the engine power is also reduced by 5.77%, 14.23% and 25.41%, and the brake specific energy consumption is increased by 3.31%, 7.78% and 6.37%. The addition of DTBP in methanol/biodiesel could recover the engine power to the level of diesel. DTBP shows good effect on the reduction of the brake specific energy consumption and NO_(x), CO, HC concentration, but a little increase of exhaust smoke.

Diesel Engine Emissions and Performance Characteristics under Cape Chestnut Biofuel

Cape Chestnut oil was processed to biodiesel through transesterification. Cape Chestnut kennels are reported to have oil content of 60% - 63% [1]. Properties of biodiesel were determined and compared with those of diesel and engine tests done at a constant speed of 1500 RPM on the biodiesel blends to evaluate their performance and emissions characteristics. Performance evaluation was in terms of Brake Specific Fuel Consumption (BSFC), Brake Horse Power (BHP) and Brake Thermal Efficiency (ETE). The engine was initially run on diesel to establish the reference characteristics before running on biodiesel blends. The biodiesel was blended with diesel volumetrically to 80% (B80), 50% (B50), 20% (B20) and 5% (B5) the percentage being the volume of biodiesel in the blended fuel. Diesel fuel had the lowest BSFC followed by B5 whose BSFC was 7.3% higher than that of diesel. BTE for B100 was lower than that of diesel by 20.3% while that of B5 was 7.6% lower. Concentration of SO2 in B100 was 92.7% lower than that of diesel fuel while that of B20 was 24.7% lower. NO and NO2 concentrations for B100 were around 15% higher than that of diesel. Particulate matter of less than 10 μm diameter (PM10) for diesel was found to be 72% of the total collected from all the test fuels as compared to that of biodiesel blends at 28%. The study concluded that Cape Chestnut biodiesel blends containing up to 20% biodiesel can be used in an unmodified diesel engine since their performance and emission characteristics were very similar to that of diesel but with reduced toxic gas emissions therefore friendly to the environment.

Application of Taguchi’s Orthogonal Array in Multi Response Optimization of NO_xEmission of Crude Rice Bran Oil Methyl Ester Blend as a CI Engine Fuel

In this work an attempt was made to minimize the NOx emission of a crude rice bran oil methyl ester (CRBME) blend with less sacrifice on smoke density and brake thermal efficiency. Three factors namely fuel injection timing, percentage EGR and fuel injection pressure were chosen as the influencing factors for the set objective. Experiments were designed by employing design of experiments method and Taguchi’s L9 orthogonal array was used to test the engine. MRSN ratio was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi’s parametric design. ANOVA was employed to analyze the variance of MRSN and the most influencing factor for the set objective was taken from the ANOVA table. Obtained combination was confirmed experimentally and significant improvement was observed in the response variables.