Passenger Car Gasoline Engine Research Articles

USE OF UREA FOR CLEANING USED SEMI-SYNTHETIC MOTOR OILS

During the operation of motor vehicles with gasoline or diesel internal combustion engines, motor oil is exposed to high temperatures, is constantly in contact with metals, its hydrocarbon part undergoes chemical transformations, is contaminated by wear products of metal surfaces, decomposition of additives, and residues of incomplete combustion of fuel. As a result, motor oil undergoes irreversible changes in its high-quality chemical composition and loss of operational properties. The paper describes the results of the study of the process of cleaning exhausted semi-synthetic motor oils in the presence of crystalline urea. Castrol 10W-40 oil, widely used in truck diesel engines, and ELF Evolution 700 STI oil, used in passenger car gasoline engines, were chosen as used semi-synthetic motor oils. The influence of the main factors of process control (the amount of urea, duration, and temperature) on the change in the functional properties of refined motor oils was studied. It was established that the lowest values of defective indicators (acid number, water content, ash content, content of mechanical impurities) were obtained at 140 ºС, duration of 80 min., and 5 mass. % of crystalline urea. In addition, there is a slight increase in the values of kinematic viscosity and viscosity index. The method of X-ray fluorescence analysis confirmed that the content of metals decreased in urea-treated oils compared to used ones. IR spectroscopic research demonstrated that under the established optimal conditions of the purification process with crystalline urea, the content of oxygen-containing "aging" products (aldehydes, ketones, alcohols, ethers, esters, organic acids) in purified semi-synthetic motor oils significantly decreased. It is proposed to use the process of cleaning used semi-synthetic motor oils in the presence of crystalline urea as an intermediate stage of the combined technological cycle of regeneration of used motor oils.

An experiment of lubricating oil gas concentration in the standardized driving cycles

There always is cavitation in the positive displacement pump, and the bubbles in the lubricating oil have a great influence on the lubricating performance. This paper aims to measure the lubricating oil gas concentration of a passenger car gasoline engine in the standardized driving cycles. We use a passenger car engine lubricating system in the lubricating experiment, simulating the lubricating oil pump working state in the standardized driving cycles. The lubricating oil density and flow rate are measured to calculate the gas concentration in the lubricating oil, according to the engine work state in the standardized driving cycles, including NEDC Urban, NEDC Ultra Urban, WLTC High Speed. The test results show that under the steady-state conditions, the gas volume ratio decreases linearly with the increase of the outlet pressure, the air mass ratio increases with the increase of the pump speed. In the driving cycles, the air mass ratio also increases with the increase of outlet pressure, and it has a high positive correlation with lubricating oil flow and pump speed. With the increase of oil temperature from 25 to 100°C, the air volume ratio decreases by 72.6%, and the air mass ratio decreases by 84.3%. In the engine accelerating state, the rate of lubricating oil flow gain lags behind the pump speed, which makes the lubricating oil gas mass ratio in the accelerating state is significantly higher than that in the decelerating state.

In situ multimodal imaging for nanoscale visualization of tribofilm formation

A third of the energy from fuel combustion in passenger car gasoline engines is lost due to friction. Carefully designed engine lubricants can recover some of these losses by reducing friction and wear by forming a nanometer-scale chemico-physico tribofilm between surfaces. Accordingly, attention has focused on developing oil formulations that form low-friction tribofilms. However, analyses of resultant tribofilms are typically conducted after tribo-tests with conventional characterization tools and do not offer insights into tribofilm formation and evolution, precluding information critical to tuning tribofilm properties. In this work, we developed a unique multimodal methodology based on Atomic Force Microscopy (AFM) with local probe heating for in situ tribological studies that activates friction modifiers and simultaneously captures the evolution of friction and surface roughness, with nanometer resolution. As a platform to demonstrate the ability of this methodology to visualize dynamics of tribofilm formation in situ, we apply it to molybdenum-based friction modifiers to distinguish key factors in their functionality and correlate nanoscale AFM and Friction Force Microscopy data to bench tribo-tests used in the industry. To decode the formation mechanisms observed in situ and underlying chemistry of tribofilms, we performed ab initio Molecular Dynamics (AIMD) simulations at comparable conditions. AIMD simulations confirmed both nanoscale and bench tribo-test results and showed deviations in molecular organization in tribofilms that are formed from different molybdenum-based friction modifiers that corroborates with surface functionality. With this innovative methodology, we demonstrate proof-of-principle in situ formation of molybdenum-based tribofilms directly on steel surfaces that could be applied generally to studying tribofilm formation.

On the improvement by laser ignition of the performances of a passenger car gasoline engine.

Laser ignition was used to operate a four-stroke, four-cylinder, multipoint fuel injection gasoline passenger car engine, replacing the engine classical ignition device. The laser ignition system was compactly built with diode end-pumped Nd:YAG/Cr4+:YAG composite ceramics, each laser spark plug delivering pulses at 1.06 μm with 4 mJ energy and 0.8ns duration at variable repetition rate, in accordance with the engine speed. The engine was operated at constant speed-constant load condition of 2000 rpm-2 bar equivalent brake mean effective pressure, and different ignition timings, thus simulating city traffic situations. Two relative air-fuel ratios have been considered: λ~1 for the stoichiometric mixture operation and λ~1.25 for the lean mixture condition. Parameters indicating engine performance, efficiency, combustion stability, and emissions have been measured and registered when groups of 500 consecutive cycles were acquired. The engine brake power, brake specific fuel consumption, coefficient of variability for indicated mean effective pressure, initial and main combustion stage durations, as well as exhaust emissions like carbon monoxide (CO) and total unburned hydrocarbons (THC) emphasized that significant improvements can be obtained for lean air-fuel mixture operation. Increases of the nitrogen oxides emission (NOx) were measured when laser ignition was used.

Experimental analysis of the V-Charge variable drive supercharger system on a 1.0 L GTDI engine

A compound charging system that pairs a turbocharger with a supercharger seems to be a potential trend for future passenger car gasoline engines, as the strength of both could be enhanced and the deficiencies of each could be offset. The use of a fixed-ratio positive-displacement supercharger system on a downsized turbocharged gasoline engine has already appeared on the market. Although such systems can achieve enhanced low-end torque and improved transient response, several challenges still exist. An alternative solution to the fixed-ratio positive-displacement supercharger is the V-Charge variable ratio centrifugal supercharger. This technology utilizes a Torotrak continuously variable transmission (CVT) coupled to a centrifugal compressor for near silent boosting. With a wide ratio spread of 10:1 and rapid rate of ratio change, the compressor speed can be set independently of the engine speed to provide an exact boost pressure for the required operating points, without the need to recirculate the air through a bypass valve. A clutch and an active bypass valve can also be eliminated, due to the CVT capability to down-speed, thus improving the noise vibration and harshness performance. This paper will, for the first time, present and discuss the V-Charge technology optimization and experimental validation on a 1.0 L GTDI engine to achieve a better brake specific fuel consumption and transient response over the turbo-only and the fixed-ratio positive-displacement supercharger solution. The potential for the V-Charge system to increase the low-end torque and enable a down-speeding strategy is also discussed.

A comparative study on various turbocharging approaches based on IC engine exhaust gas energy recovery

In this paper, two kinds of novel boosting pressure approaches, steam turbocharging and steam-assisted turbocharging, have been proposed. And both are based on the principle of internal combustion (IC) engine exhaust gas energy recovery. In order to demonstrate the advantages of the two types of new turbocharging concepts, a comparative study among exhaust turbocharging, steam turbocharging and steam-assisted turbocharging was conducted on a passenger car gasoline engine, and the effects of various boosting pressure approaches on IC engine performances as well as turbocharging system energy flow were analyzed. The results show that, steam turbocharging can achieve the target intake pressure in the entire IC engine speed range, while steam-assisted turbocharging can improve IC engine intake pressure at the low-speed operating conditions; the energy saving potentials from high to low follow the subsequence of steam turbocharging, steam-assisted turbocharging and exhaust turbocharging; with the increasing of IC engine speed, the exhaust gas energy recovery efficiency of steam turbocharging system decreases and its maximum value is 6.5%, while the exhaust gas energy recovery efficiency of steam-assisted turbocharging and exhaust turbocharging first increases and then decreases.

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.

Research on Hydrocarbon Emission Regularity of Passenger Car

To analyse and research the idle hydrocarbon emission regularity of passenger car gasoline engine, based on large sample detected data of different type cars, parameter estimation and hypothesis test are carried on by statistical tools and neans, and the optimum distribution parameters of idle hydrocarbon emission of different type engines are also got. Then the optimum distribution models of these engines are established. The calculating result shows that the maximum error between model calculating and sample detecting certification rates is only 0.526 8%, and the established models have very high calculating precision and practical value. On the other hand, the research also shows that the inspect and maintenance program should be strengthen in order to control vehicle emission pollution effectively.

403 環境対応ガソリンエンジンにおける排気バルブシートの開発

The recent passenger car gasoline engines have oriented for low fuel consumption and low emission due to the eco-friendly requirements. As the concrete problem to develop the eco-friendly engine, the exhaust valve seat insert is exposed to severe wear condition by friction due to the rise of combustion temperature with the progress of the lean burn. This paper is to introduce the exhaust valve seat insert which we have developed for this kind ofeco-friendly gasoline engine.

Tribological aspects of by‐pass oil filters on gasoline passenger car engines

AbstractContaminants in passenger car engines are physically separated from lubricating oil by full flow oil filters. The additional cleaning in by‐pass filters should allow oil drain intervals to be extended or to operate engines without oil change and reduce engine wear noticeably, as claimed by some by‐pass filter manufacturers.To establish whether the claim is mere conjecture or if the addition of by‐pass filters into the oil circuits of passenger car gasoline engines are indeed of real benefit with respect to engine and lubricant performance, a research project was initiated by the UBA on behalf of the German environment ministry.Special attention had to be paid to the influence on oil contamination, variation in viscosity, detergency, dispersancy, fuel and oil consumption, engine wear and overall reliability and durability. Some highlights of the total programme are presented in this paper.

Electronic Control of Fuel Injection for Passenger Car Gasoline Engine

A unique electronically controlled fuel injection system, named ECI, has been jointly developed by Mitsubishi Motors Corporation, Mitsubishi Electric Corporation and Mikuni Kogyo Co., LTD. for 2.0-and 2.6-liter passenger-car gasoline engines.The system incorporates a vortex-shedding air-flow sensor, a single-point injection assembly and a microprocessor control unit.This paper presents descriptions of physical arrangement, components and control strategy of the ECI system.