Engine emission and performance effects of ethanol addition into fuel at internal combustion engines

Along with worldwide developing technology, automotive industry develops in parallel with these developments. The vehicles which is produced in Turkey and all over the world is being sold quickly and also presented to customers' like with a lot of different brands. In order to increase the sales figures, competing with other brands, continous development and studies are on going inconformity with the customers criterias. These requirements and customer's likes are supported with the new generation techniques. These improvements and developments are vehicle performance improvements as well as vehicle design improvements. That' s why market demand for engines as a future concept is to increasing the efficiency and minimum fuel consumption. However with these developments and improvements in the world, we face some health problems due to wastes of these developments and improvements. In the 21st century, despite the research on the electric and hybrid engines internal combustion engines are still have the domination. Major developments in internal combustion engines are focused on the engine efficiency and emissions reduction. This focus is driven by the potentially damaging effect of global warming and the depletion of fossil fuels. The worlwide health organizations, envorimental organizations and also the goverments are attracting the attention of the people to these health problems. These health problems are very critical for the human bodies and the world's enviroment. That's why, we need to prevent these waste's side effects to save our world's future and also leave better and liveable world to our children. One of this health problem's factor which caused by this improvements and developments is the automotive industry. There are a lot of studies which aimed to prevent the air pollutant gases formation which caused by vehicles. Many goverments are also supporting these studies with placing restrictios on these air pollutant gases emissions. They are limiting the emissions of the air pollutant and harmful gases which are unhealty to human health to support these studies. In addition of this limitation, goverments are not allowing the sales of the vehicles which are not appropriate these standards. Turkey, United States, Japan, European countries are the several examples which limit these unhealthy gases emissions. On the other hand, the world's oil reserves are depleting and consuming too rapidly. There has been intensive researchs to find out alternative to fossil fuels to reduce the dependency on the conventional petroluem reserves. The main group is the bio – fuels which are produced from crops and wastes is alcohols. The main idea is to blend the fuel with alcohols and decrease the gasoline amount in the fuel. To decrease the fuel consumption and the depency of the fossil energy sources at the vehicle, scientists are keep on studying. There are a lot of methods and studies on these aim. One of the method of to decrease the fuel consumptions using alternative fuels at engines. There are several alternative fuels to gasoline however one of the most popular one is the Ethanol. Ethanol' s chemical properties and storable feature also the more cheaper benefit are the several advantages to be chosen as an additive into gasoline. The aim of this study is to adding ethanol with different amounts in the fuel and examine the consequences and positive effects on the engine performance and emissions. Another method to decrease the fuel consumption is supercharging and turbocharging the engine. The aim of the supercharging and turbocharging is increasing the inlet pressure of the engine cylinder and trying to get more efficient engine. In this study the inlet pressure of the internal combustion engine is increased and tryed to get more power and less air pollutant and unhealty gases emission at the same speed of engine. At classic supercharging and turbocharging studies, cylinder volume is decreased in addition to inlet pressure increasing. However in this study, cylinder volume is kept same against inlet pressure increment. The reaso is to change just one variable in the engine to investigate inlet pressure increment effect on engine performance and emissions. In this study, four cylinder internal combustion engine is modelled and this modelling is made in AVL Boost software as 1D simulation. The advantage of the 1D simulation is used, quick solution and more simple modelling in AVL Boost's Library. Four cylinder internal spark ignited combustion model is used which is stored AVL Boost' s Library. The engine parameters are defined in the library also. After model selecting, Vibe 2-Zone Combustion Model is used for combustion modelling. At the all of the operating conditions, the spark advance is chosen between -5 to -20 degrees and where the maximum cylinder pressure reachs maximum value after 10 – 15 degrees of cranck angle, that spark advance is used to define engine performance and the emission results. The aim to change the spark advance in each simulation is to define the best operating conditions in different speeds, different ethanol ratio, air / fuel ratio, inlet cylinder pressure. All of the simulations are done between 1000 – 5000 rpm in order to see how engine is reacting ethanol addition and inlet pressure increasing wih low speed and also high speeds. Also at all of the simulations, engine is operateed at full load condition. In order to see the emissions, Classic Species of Transport is selected for emission models. At the first stage of this study, just different ethanol ratios are blended into the gasoline and the engine perfomance, engine emissions are investigated. Firstly the aim is to examine the ethanol addition in the gasoline and compare the results according initial ( no ethanol added fuel ) engine operating conditions. The study and the simulation results shows that the power of the engine is decreases when ethanol added into the fuel. On the other hand, NOx and CO emissions are decreasing and the HC emissions are increasing. At the second stage of this study, the air / fuel ratio of the fuel charge is changed and the effect of lean fuel on the engine performance and engine emissions are examined. The simulation results of the lean fuel shows that the engine power decreases however with the same operating conditions at initial conditions fuel consumption decreases. There are reductions at engine emissions for HC and CO. On the other hand, results shows that NOx emissions are increasing with lean fuel. At the third stage of this study, the inlet pressure of the internal combustion engine is increased and the best operating conditions in respect to healthy and more efficiency. The goal of this study is in respect to engine resistance to high pressure and high temperatures to get maximum 2 times bigger cylinder pressure. To avoid too much high pressure in the cylinder, compression ratio of the engine is tunned between 8 – 10.5. At the end of this study, when the inlet pressure of the cylinders are increased, the cylinder pressure and engine power increases, correspondingly the engine tork increases and accordingly the fuel consumption increases. By the way, HC and CO emissions decreases however NOx emissions are increases.