عنوان مقاله [English]
Fuel additives are a promising engineering solution to achieve clean combustion with high thermodynamic efficiency. Combustion quality in a variety of internal combustion engines is significantly correlated with the thermophysical properties of the fuel. Accordingly, there is a significant tendency to develop a new formulation of gasoline fuel to increase braking power and reduce fuel consumption of spark ignition engines and reduce their emissions. For this purpose, the present study was dedicated to investigating a gasoline engine's performance changes and emissions by gasoline mixtures and ethanol and thinner additives. Part of this research is an attempt to investigate the effect of fuel samples on engine vibration to achieve a fuel mixture that reduces pollution, increases engine performance, and increases engine life. All tests were performed at constant engine speed and full engine load. After obtaining experimental data, the effects of single additives and their interaction were analyzed using statistical software such as. Based on the results, it can be said that integrated additives can be a good way for future studies in terms of the performance and pollution of gasoline engines. These additives can also be studied in terms of the engine's durability. It is suggested in future studies to use samples of fuels with high percentages of mixing with thinner and ethanol additives for a more detailed study.
In this study, gasoline was used as a control fuel, and thinner and ethanol were used as diesel additives (at three levels of 2, 4, and 6%). A homogenizer (Polytron® Switzerland) was used to stabilize the fuel sample at room temperature for 15 minutes.
The prepared fuel samples were poured into half-liter bottles and then experimentally tested in a four-stroke single-cylinder ignition engine, model rme1000, with a displacement volume of 98 ccs and a maximum power of W800. In this study, in order to use fuel samples in the rme1000 generator engine and measure the amount of fuel consumed by installing a separate duct behind the carburetor and installing a valve in the fuel transfer path, an attempt was made to control the fuel consumed. In this way, the fuel could be measured from a separate tank by passing through a calibrated glass tube by the method of movement and the primary tank and the built-in valve; we could access the control fuel at any time. A variable resistor of TDGC2-5kVA type and a 1 kW heater were used to load the motor. The number of amps and voltage was measured by measuring the motor power (the product of amperes and direct voltage (DC) shows the amount of power consumed). The pollutant model QRO-401 made by QROTECH company was used to measure the number of pollutants emitted from the engine exhaust.
A VIBRO RACK 1000 analyzer system was used to measure the engine's vibration due to combustion, which produces outputs in the form of broken waves. This device works with the help of a computer that is connected by network cables. Sensors were placed to measure the sensors on the motor block to reduce vibration errors and be ready for evaluation in the X, Y, and Z directions when the motor is started. The end parts of the sensors were threaded and connected to the engine block in rotation.
One of the most important parts for measuring vibration is the sensors used in which directions to measure, and also the end of the sensor, which is located in the direction of each of the axes, should be placed somewhere closed or in a firm position to transmit the blows and vibrations to the complete state.
This study was conducted to study the effects of ethanol and thinner additives on performance, greenhouse gas emissions, and fuel consumption of single-cylinder, four-stroke gasoline in which gasoline additives were combined with a research octane number of 88. The research was performed on a single-cylinder gasoline engine. The results were evaluated from the perspective of engine performance, pollution and vibration, and based on the observations, suggestions were made. According to this:
Adding thinner and ethanol to the samples of gasoline-containing fuels reduces the calorific value of the fuel and increases the density and viscosity, which can have a significant effect on the quality of combustion.
- It can be said that the addition of thinner and ethanol alone has caused a relative increase in fuel consumption. This trend is due to the decrease in calorific value of fuel samples containing thinner and ethanol compared to natural gasoline fuel.
- It can be seen that the addition of thinner ethanol has relatively reduced carbon monoxide emissions compared to the control fuel. This trend can be due to oxygen in the sample contents of fuels containing thinner and ethanol.
- On average, carbon dioxide emissions in samples with additives other than GT1E6, GT3E4, and GT3E6 are higher than in control fuel (gasoline). The trend of increasing carbon dioxide emissions from the GT5E2 fuel sample onwards is highest.
- On average, oxygen emissions are lower than in the control sample, except in GT0E2, GT0E4, GT0E6, and GT1E6 fuel samples. Low oxygen in the output can be a reason for reducing oxygen content in the output. It can promise high oxygen consumption in the combustion formulation due to complete combustion.
- The highest emissions of nitrogen oxides are related to GT5E2, GT5E4, and GT5E6 fuel samples. Also, the lowest emissions of nitrogen oxides are related to GT1E0 and GT1E6 fuel samples. In cases where the emission of nitrogen oxides is high, it is recommended to strengthen the engine cooling system. Alternatively, use ORC cycles to absorb as much energy as possible released into the combustion chamber to increase energy production stability.
- Based on the results, it can be seen that increasing the percentage of thinner and ethanol additives in the fuel sample has reduced the vibration of the gasoline engine compared to the control fuel sample.
Based on what has been obtained from previous sections and this section, it can be said that integrated additives can be a good way forward for future studies both in terms of performance and pollution and in terms of examining engine durability because these types of additives benefit from several types of additives and reduce the disadvantages of existing fuels. It is suggested in future studies to use samples of fuels with high percentages of mixing with thinner and ethanol additives for a more detailed study.