发动机传感器:让汽车更节能

应用于发动机启停系统的曲轴和凸轮轴位置传感器能够精确监测活塞位置,对发动机喷油和点火时间进行优化,从而有效减少燃油消耗和CO2排放。发动机传感器作为检测发动机状态的"电子眼",能有效提升发动机燃油消耗性能大陆集团推出了应用于发动机启停系统（Start&Stop）的曲轴和凸轮轴位置传感器,其中带方向检测的曲轴位置传感器（CPDD）具有方向检测功能、灵敏度高。

Design of speed controller for electronic fuel injection gasoline generator based on feed-forward PID control

As for the application of electronic fuel injection （EFI） system to small gasoline generator set, mechanical speed controller cannot be coupled with EFI system and has the shortcomings of lagged regulation and poor accuracy, a feed-forward control strategy based on load combined with proportional-integral-differential （PID） control strategy was proposed, and a digital speed controller applied to the electrical control system was designed. The detailed control strategy of the controller was intro- duced. The hardware design for the controller and the key circuits of motor driving, current sampling and angular signal captu- ring were given, and software architecture was discussed. Combined with a gasoline generator set mounted with EFI system, the controller parameters were tuned and optimized empirically by hardware in loop and bench test methods. Test results show that the speed deviation of generator set is low and the control system is stable in steady state; In transient state the control system responses quickly, has high stability under mutation loads especially when suddenly apply and remove 100% load, the speed deviation is within 8% of reference speed and the transient time is less than 5 s, satisfying the ISO standard.

Effects of working parameters on gasoline engine exergy balance

To improve the energy utilization efficiency of internal combustion （IC） engine, exergy analysis was conducted on a passenger car gasoline engine. According to the thermodynamic theory of IC engine, in-cylinder exergy balance model was built. The working processes of gasoline engine were simulated by using the GT-power. In this way, the required parameters were calculated and then gasoline engine exergy balance was obtained by programming on computer. On this basis, the influences of various parameters on exergy balance were analyzed. Results show that, the proportions of various forms of exergy in gasoline engine from high to low are irreversible loss, effective work, exhaust gas exergy and heat transfer exergy. Effective exergy proportion fluctuates with cylinder volumetric efficiency at full load, while it always increases with break mean effective pressure （BMEP） at part load. Exhaust gas exergy proportion is more sensitive to speed, and it increases with speed increasing except at the highest speed. The lower proportion of heat transfer exergy appears at high speed and high load. Irreversible loss is mainly influenced by load. At part load, higher BMEP results in lower proportion of irreversible loss; at full load, the proportion of irreversible loss changes little except at the highest speed.

Modelling of modern automotive petrol engine performance using Support Vector Machines

Modern automotive petrol engine performance is significantly affected by effective tune-up. Current practice of engine tune-up relies on the experience of the automotive engineer, and tune-up is usually done by trial-and-error method and then the vehicle engine is run on the dynamometer to show the actual engine performance. Obviously the current practice involves a large amount of time and money, and then may even fail to tune up the engine optimally because a formal performance model of the engine has not been determined yet. With an emerging technique, Support Vector Machines (SVM), the approximate per- formance model of a petrol vehicle engine can be determined by training the sample engine performance data acquired from the dynamometer. The number of dynamometer tests for an engine tune-up can therefore be reduced because the estimated engine performance model can replace the dynamometer tests to a certain extent. In this paper, the construction, validation and accuracy of the model are discussed. The study showed that the predicted results agree well with the actual test results. To illustrate the significance of the SVM methodology, the results were also compared with that regressed using multilayer feedforward neural networks.

Auto-Ignition and Heat Release Correlations for Controlled Auto-Ignition Combustion in Gasoline Engines

Auto-ignition and heat release correlations for controlled auto-ignition(CAI)combustion were derived from extensive in-cylinder pressure data of a four-stroke gasoline engine operating in CAI combustion mode.Abundant experiments were carried out under a wide range of air/fuel ratio,speed and residual gas fraction to ensure that the combustion correlations can be used in the entire CAI engine operation range.Furthermore,a more accurate method to compute the residual gas fraction was proposed by calculating the working fluid temperature at the exhaust valve close timing in the experiments.The heat release correlation was described in two parts,one is for the first slower heat release process at low temperature,and the other is for the second faster heat release process at high temperature.Finally the heat release correlation was evaluated on the single cylinder gasoline engine running with CAI combustion by comparing the experimental data with the 1-D engine simulation results obtained with the aid of the GT-Power simulation program.The results show that the predicted loads and ignition timings match closely with the measurements.

Fuel Burning Rate Model for Stratified Charge Engine

A zero-dimensional single-zone double-curve model is presented to predict fuel burning rate in stratified charge engines, and it is integrated with GT-Power to predict the overall performance of the stratified charge engines. The model consists of two exponential functions for calculating the fuel burning rate in different charge zones. The model factors are determined by a non-linear curve fitting technique, based on the experimental data obtained from 30 cases in middle and low loads. The results show good agreement between the measured and calculated cylinder pressures, and the deviation between calculated and measured cylinder pressures is less than 5%. The zerodimensional single-zone double-curve model is successful in the combustion modeling for stratified charge engines.

Effect of Gasoline Property on Formation of Intake Valve and Combustion Chamber Deposits

The cleanliness of gasoline is related to its components and properties.All commercial gasoline builds up deposits on the engine's injector,intake valve and combustion chamber,which can significantly lower the engine performance and influence exhaust gas emissions.In this study,the intake valve deposits (IVD) and combustion chamber deposits (CCD) produced from combustion of fuel containing 21 v%—42 v% of aromatics and 8 v%—31 v% of olefins have been studied using Ford engine tests,and the characteristics of deposits were studied by IR spectroscopy,TGA and elemental analysis instrument.The test results have shown that deposit formation depends on the fuel composition,especially the aromatic content in the fuel.It is also observed that there are differences in the values of IVD and CCD measured by IR spectrometry and elemental analyses.

Kinematic Viscosity and Shear Stress of Used Engine Oil

The goal of this paper describes kinematic viscosity and shear stress of two used engine oils, which have been taken from two different passenger cars. Kinematic viscosity and shear stress are two of the most important physical behaviours of fluids, especially lubricating fluids. In this paper the authors have focused on engine oil. Knowledge of these properties of engine oil is very important due to its lifetime. The experiments have been done using digital rotary rheometer Anton Paar DV-3 P with use of TR8 spindle and special adapter for a small amount of sample （20 mL）. Two different engine oils have been observed--first from passenger car Renault Scenic with petrol engine （engine capacity 1.6 dm3） and the second from passenger car Skoda Roomster with diesel engine （engine capacity 1.4 dm3）. Castrol Magnatec 10W-40 engine oil has been taken from Renault car and Shell Helix Ultra Extra 5W-30 engine oil has been taken from ~koda car. Service interval of change oil has been set to 15,000 km and samples of used engine oils have been taken after 1,500 km. Only first samples of used engine oils have been taken after raid of 20 km. All samples of used engine oils have been compared with new （unused） engine oils same specification. The measured values of kinematic viscosity and shear stress have been modeled using linear function. The coefficients of correlation R have been achieved high values （0.88-0.96）. The obtained models can be used to prediction of engine oil flow behaviour.

One of the Scenarios for Reduction the Emission of Pollutants from Motor Vehicle in the Territory of the Republic of Kosovo

Together with development of the industry, there is present a continuous increase number of motor vehicles that contributes to the growth of the emission of pollutants. This is the main reason that during eighties of the last century, a special attention has started to be paid on pollution emissions from vehicles. It is important to note that most of the current emissions are formed directly and are present in urban areas. The aim of this research was to determine the emission of pollutants in the territory of the Republic of Kosovo, when circulates more than 380,000 motor vehicles. Taking into consideration the daily traffic jam, and the fact that gasoline engines are responsible for most emissions of CO, while diesel engines for NOx emission, the conclusion arises that there is necessary a special dedication to the emission of pollutants and to the definition of the measures to reduce or control them. Based on the performed tests and realistic assessment of the overall situation in the Republic of Kosovo, the current situation on the amount of pollution was compared with development countries in the region as a matter in the research. The results obtained, suggest to the most important causes that increase pollutant emission from motor vehicles and offer actions to keep the same level or to reduce them.

Strategy on Development of Gasoline and Diesel Standards in China with Reference to Overseas Practice for Upgrading Gasoline and Diesel Quality

This article analyzes the standards for car exhaust emissions and gasoline and diesel quality in Europe and the US. As revealed by the evolution of gasoline and diesel standards in China, the gasoline and diesel compositions of China and the exhaust gas emissions standard are closely related with the specifics of the petroleum refining industry and automotive industry in China. After studying the current situations of gasoline and diesel quality in China while taking into account the commonly accepted practice in the overseas this article raises some suggestions on development of gasoline and diesel standards in compliance with the actual conditions of China.

Performance Evaluation of Spark Ignited Engine Fueled with Gasoline-Ethanol-Methanol Blends

In this paper, experimental investigations are presented to assess the performance variations in a single cylinder spark ignited engine when run with three different gasoline-alcohol blends： （88% gasoline-12% methanol, 88% gasoline-12% ethanol and 88% gasoline-6% methanol-6% ethanol）. Additional tests are carried out with the basic gasoline fuel for comparison analysis and performance assessment. Engine performance is investigated under a variety of engine operating conditions. The results are presented in the domain of engine speed. In particular, the brake power of the engine is shown to be slightly increased. The brake thermal efficiency showed an increase compared with the basic gasoline engine. Similarly, it is shown that brake specific fuel consumption is enhanced compared with basic gasoline engine. The exhaust gas temperature showed a decrease compared with gasoline fuel which is preferable to reduce emissions. The alcohol additives are strongly recommended to enhance performance, increasing the mileage and reducing the emissions.

Optimal Simulation of Distributed Generation System for CO_2-Reduction in Supermarket and Restaurant

After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data： distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV （photovoltaic） panel, PCM （phase change material）, thermal storage, FCU （fan coil unit） and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.

Three-dimensional transient numerical simulation for intake process in the engine intake port-valve-cylinder system

This paper presents a KIVA-3 code based numerical model for three-dimensional transient intake flow in the intake port-valve-cylinder system of internal combustion engine using body-fitted technique, which can be used in numerical study on internal combustion engine with vertical and inclined valves, and has higher calculation precision. A numerical simulation (on the intake process of a two-valve engine with a semi-sphere combustion chamber and a radial intake port) is provided for analysis of the velocity field and pressure field of different plane at different crank angles. The results revealed the formation of the tumble motion, the evolution of flow field parameters and the variation of tumble ratios as important information for the design of engine in-take system.

Study on Using Mixed Fuel of Jet Fuel/Gasoline as Fuel of Gasoline Engine

This paper has integrated various methods such as laboratory physical and chemical analysis, engine bench test and actual road test, etc. to conduct a feasibility study on the emergency alternative fuel of gasoline by mixed jet fuel and gasoline. The study shows that both the evaporability and anti-knock quality decrease after mixing jet fuel with gasoline. While the mixing proportion increases, the engine power decreases and the fuel consumption increases gradually. When the proportion reaches 40%, the engine power drops by 5.3% to 11.7%, the fuel consumption rises by an average of 3.8%, and meantime the oil dilution and emission of the engine power become worse. Therefore, as for the gasoline engine, the mixed oil can only be used as emergency alternative fuel due to its harm to the engine.

Modeling and multi-objective optimization of a gasoline engine using neural networks and evolutionary algorithms

In this paper, a multi-objective particle swarm optimization （MOPSO） algorithm and a nondominated sorting genetic algorithm II （NSGA-II） are used to optimize the operating parameters of a 1.6 L, spark ignition （SI） gasoline engine. The aim of this optimization is to reduce engine emissions in terms of carbon monoxide （CO）, hydrocarbons （HC）, and nitrogen oxides （NOx）, which are the causes of diverse environmental problems such as air pollution and global warming. Stationary engine tests were performed for data generation, covering 60 operating conditions. Artificial neural networks （ANNs） were used to predict exhaust emissions, whose inputs were from six engine operating parameters, and the outputs were three resulting exhaust emissions. The outputs of ANNs were used to evaluate objective functions within the optimization algorithms： NSGA-II and MOPSO. Then a decision-making process was conducted, using a fuzzy method to select a Pareto solution with which the best emission reductions can be achieved. The NSGA-II algorithm achieved reductions of at least 9.84%, 82.44%, and 13.78% for CO, HC, and NOx, respectively. With a MOPSO algorithm the reached reductions were at least 13.68%, 83.80%, and 7.67% for CO, HC, and NOx, respectively.

Friction and wear of sand-contaminated lubricated sliding

This paper reports a test investigation of friction and wear responses from sand contaminated lubricated sliding. The influence of sand contaminants on wear and friction is characterized. Analyses are completed utilizing segments of piston ring sliding against the cylinder liner. Paraffin oil, with and without sand contaminants, is utilized. The effects of the concentration and particle size of sand are examined. Based on the observations in the present work, we found that friction and wear increase with sand concentration in the lube. Solid proposals ought to be considered, in order to enlighten the general population on the importance of changing a car engine's oil filter regularly.

Effect of rich air/fuel ratio and temperature on NO_x desorption of lean NO_x trap

An experimental and model-based study of the effect of rich air/fuel ratios(AFRs) and temperature on the NOx slip of a lean NOx trap(LNT) was conducted in a lean-burn gasoline engine with an LNT after-treatment system. The emissions of the engine test bench and the inlet temperature of the LNT were used as the major inlet boundary conditions of the LNT. The engine periodically operated between a constant lean AFR of 23 with alterable rich AFRs of 10, 11, 12, 13, and 14. A decrease in the rich AFR of the engine strengthened the desorption atmosphere in the LNT, an effect closely related to the number of reductants, and further heightened the NOx desorption of the LNT, but with a penalty in fuel consumption. To eliminate that penalty, the inlet boundary conditions of the LNT were varied by adjusting the inlet temperature within a range between 200℃ and 400℃. An increase in inlet temperature heightened the NOx desorption of the LNT, and a NOx breakthrough occurred after the inlet temperature exceeded 390℃. To control NOx breakthrough, the inlet temperature can be adjusted to offset the strong desorption atmosphere in the LNT commonly created by a rich AFR.

Role of ammonia in forming secondary aerosols from gasoline vehicle exhaust

Ammonia(NH3) plays vital roles in new particle formation and atmospheric chemistry. Although previous studies have revealed that it also influences the formation of secondary organic aerosols(SOA) from ozonolysis of biogenic and anthropogenic volatile organic compounds(VOCs), the influence of NH3 on particle formation from complex mixtures such as vehicle exhausts is still poorly understood. Here we directly introduced gasoline vehicles exhausts(GVE) into a smog chamber with NH3 absorbed by denuders to examine the role of NH3 in particle formation from GVE. We found that removing NH3 from GVE would greatly suppress the formation and growth of particles. Adding NH3 into the reactor after 3 h photo-oxidation of GVE, the particle number concentration and mass concentrations jumped explosively to much higher levels, indicating that the numbers and mass of particles might be enhanced when aged vehicle exhausts are transported to rural areas and mixed with NH3-rich plumes. We also found that the presence of NH3 had no significant influence on SOA formation from GVE. Very similar oxygen to carbon(O:C) and hydrogen to carbon(H:C) ratios resolved by aerosol mass spectrometer with and without NH3 indicated that the presence of NH3 also had no impact on the average carbon oxidation state of SOA from GVE.

Evaporate prediction and compensation of intake port wall-wetting fuel film for spark ignition engines fueled with ethanol-gasoline blends

The fuel dynamic transfer process,including fuel injection,fuel film deposition and evaporation in the intake port,was analyzed for spark ignition(SI) engines with port fuel injection(PFI).The influence of wall-wetting fuel film,especially its evaporation rate,upon the air-fuel ratio of in-cylinder mixtures was also discussed.According to the similarity principle,Fick's law,the ideal gas equation and the Gilliland correlation,an evaporate prediction model of wall-wetting fuel film was set up and an evaporate prediction based dynamic fuel film compensator was designed.Through engine cold start tests,the wall-wetting temperature,which is the key input of the fuel film evaporate prediction model,was also modeled and predicted.Combined with the experimental data of the evaporation characteristics of ethanol-gasoline blends and engine calibration tests,all the parameters of the wall-wetting fuel film evaporate prediction model used in the fuel film compensator were identified.Square-wave disturbance tests of fuel injection showed that with the help of the fuel film compensator the response of the in-cylinder air-fuel ratio was significantly improved and the real air-fuel ratio always closely matched the expected ratio.The fuel film compensator was then integrated into the final air-fuel ratio controller,and the engine tests showed that the air-fuel ratio control error was less than 2% in steady-state conditions,and less than 4% in transient conditions.The fuel film compensator also showed good adaptability to different ethanol-gasoline blends.