scholarly journals Alternative fuel in the combustion process of combustion engines

2018 ◽  
Vol 48 (1) ◽  
pp. 55-81 ◽  
Author(s):  
Antoni Jankowski ◽  
Mirosław Kowalski

Abstract The article analyses the impact of emulsified fuel, containing H2O2 hydrogen peroxide, on the emissions of nitrogen oxides and diesel engine smoke. The process of forming toxic components in exhaust gases of reciprocating engines during the engine operation, and the relationship that specifies the hydrogen peroxide decomposition process were presented. The research was carried out with the use of fuel containing 30%, 20% and 10% of hydrogen peroxide. The concentration courses of the nitric oxide (NO) and nitrogen oxides (NOx), as well as the (CO) carbon monoxide concentration and (S) engine smoke courses were shown separately for the external characteristics of the engine. Finally, the importance of knowledge related to the mechanisms of generation of toxic components in exhaust gases in the reciprocating engines was emphasised.

2015 ◽  
Vol 36 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Antoni Jankowski ◽  
Mirosław Kowalski

Abstract The paper contains analysis of the impact on the quality of the fuel spray of droplets on the number and the value of the surface area of the droplets that have a direct impact on the efficiency of the combustion process. It presents a change in the level of toxic exhaust emissions with an increase in the so-called. Sauter Mean Diameter (SMD) of fuel droplets. The presented figures show that the increase in the average droplet diameter SMD in particular causes an increase of toxic exhaust gases emissions, i.e. mainly nitrogen oxides NO, carbon monoxide CO, hydrocarbons HC and Particulate Matter (PM). This tendency is not constant, because it is changing according to changes of the coefficient of equivalence Φ. For example, emissions of nitrogen oxides for the lean mixtures (Φ <1), with an increase in average droplet diameter increases, while now for the rich mixtures (Φ> 1), this trend is significantly changed, i.e. the level of this emission decreases.


2015 ◽  
Vol 36 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Antoni Jankowski ◽  
Mirosław Kowalski

Abstract The paper analyses the mechanisms of creation of toxic exhaust gases, which mainly derived from inexact fuel metering and improper air-fuel mixture preparation. The paper describes the process of creating toxic components in the exhaust gases of piston engines during engine operation, and impact on the emission of these components determining the composition of the fuel mixture determined equivalence factor Φ. The principal mechanisms of formation of toxic exhaust gases, in particular nitrogen oxides, carbon monoxide and hydrocarbons, and also essential according to create each of toxic exhaust gases are the subject of the paper. Moreover, empirical relationships, by means of which it is possible to determine the time of creation of the individual components of toxic exhaust gases, are presented. For example, one of the mechanisms for prompt formation of nitrogen oxides and hydrocarbons graphic illustration of formation as a function of crank angle is described. At the conclusion, the summary and significance of information on creation mechanisms of toxic components in the exhaust gases of piston engines are presented.


2021 ◽  
pp. 28-32
Author(s):  
VALERIY L. CHUMAKOV ◽  

The paper shows some ways to improve the environmental characteristics of a diesel engine using gaseous hydrocarbon fuel and operating the engine in a gas-diesel cycle mode. Some possibilities to reduce toxic components of exhaust gases in a gas-diesel engine operating on liquefi ed propane-butane mixtures have been studied. Experiments carried out in a wide range of load from 10 to 100% and speed from 1400 to 2000 rpm showed that the gas-diesel engine provides a suffi ciently high level of diesel fuel replacement with gas hydrocarbon fuel. The authors indicate some eff ective ways to reduce the toxicity of exhaust gases. The engine power should be adjusted by the simultaneous supply of fuel, gas and throttling the air charge in the intake manifold. This method enriches the fi rst combusting portions to reduce nitrogen oxides and maintains the depletion of the main charge within the fl ammability limits of the gas-air charge to reduce carbon monoxide and hydrocarbons. The authors found that when the engine operates in a gas-diesel cycle mode, the power change provides a decrease in nitrogen oxide emissions of gas-diesel fuel only due to gas supply in almost the entire load range as compared to the pure diesel. At high loads (more than 80%) stable engine operation is ensured up to 90% of diesel fuel replaced by gas. Even at 10% of diesel fuel used the concentration of nitrogen oxides decreases by at least 15…20% as compared with a diesel engine in the entire load range. However, there is an increased emission of hydrocarbons and carbon monoxide in the exhaust gases. Further experimental studies have shown that optimization of the gas diesel regulation can reduce the mass emission of nitrogen oxides contained in exhaust gases in 2…3 times and greatly reduce the emission of incomplete combustion products – carbon monoxide and hydrocarbons.


2020 ◽  
Vol 181 (2) ◽  
pp. 46-52
Author(s):  
Filip SZWAJCA ◽  
Krzysztof WISŁOCKI

Gas engines are a viable source of propulsion due to the ecological indicators of gas fuels and the large amount of the needed natural resources. Combustion of lean homogeneous gas mixtures allows achieving higher thermal efficiency values, which is a key factor in current engine development trends. Using the spark-jet ignition system (also called as Turbulent Jet Ignition or Two-stage combustion) significantly improves the efficiency and stability of the combustion process, especially in the part-load operation on lean or very lean mixtures. This paper presents the impact of using two different fuel injection methods: Port Fuel Injection or Mixer on the operation stability of a gas engine designed for LDVs. Comparative studies of two different mixture preparation systems were carried out on a single-cylinder AVL 5804 test engine. By re-cording the cylinder pressure for a significant number of engine cycles, it became possible to determine the repeatability of engine operation and to correlate the results with the mixture formation system and the air-fuel ratio. In the performed research the beneficial effect of the mixer system application on the engine operation stability in the part-load conditions was found.


2020 ◽  
Vol 221 ◽  
pp. 02006
Author(s):  
Irina Belinskaia ◽  
Rahim Zainetdinov ◽  
Konstantin Evdokimov

The problem of negative impact on the environment of motor transport is one of the most fundamental in the complex of global problems. The constant increase in the number of cars with internal combustion engines encourages the search for methods and ways to reduce the volume of negative impulses. The operation of heat engines is accompanied by significant emissions of gaseous harmful substances into the atmosphere, i.e. nitrogen oxides, carbon monoxide, hydrocarbons, as well as solid particles, including soot. The solution to this problem should be implemented within the framework of a systematic approach. To do this, it is necessary to combine the study of technical, economic, and organizational approaches to the organization of the exhaust gas disposal process. To date, there is a significant methodological base in the field of organizational and economic decisions. The article discusses various methods of cleaning exhaust gases of piston engines, their advantages and disadvantages are noted. The method of processing using ammonia is widely known. It is noted that a catalytic method for reducing nitrogen oxides using ammonia is quite economical. However, the optimal temperature range at which nitrogen oxides are reduced is rather narrow. To solve this problem, it is proposed to use the vortex effect in the exhaust system. The efficiency of using a vortex gas recirculation pipe is due to its significant influence on the thermal gasdynamic processes occurring in the exhaust system. Using the principles of non-equilibrium thermodynamics allows us to take into account dissipative processes when establishing the relationship of fuel and economic indicators of internal combustion engines with thermodynamic parameters. This significantly increases the accuracy of calculations and allows you to develop measures to reduce the level of negative impact on the environment.


2021 ◽  
Author(s):  
Jianyin huang ◽  
Maximus Ghaly ◽  
Peter Hobson ◽  
Christopher W.K. Chow

Abstract The treatment and control of cyanobacterial blooms using copper-based algaecides in water reservoirs has historically been used, however, due to the adverse impact of copper on the environment, water authorities have been researching and studying new and innovative ways to control cyanobacterial blooms. Hydrogen peroxide has been investigated as an environmentally friendly alternative and this research aims to determine the impact of water quality on its effectiveness based on the decay characteristics in different water samples. Natural water samples from South Australian reservoirs were used to evaluate hydrogen peroxide decomposition and provide a better strategy for water operators in using it as an algaecide. Our experiments show the dependency of hydrogen peroxide decomposition not only on water quality but also on the initial hydrogen peroxide dose. A higher initial hydrogen peroxide dose can trigger the increase of pH, leading to increased consumption of hydrogen peroxide. In addition, the hydrogen peroxide decomposition is significantly accelerated with the rise of copper concentration in water samples. Moreover, it is found that UV light can also affect the decomposition rate of hydrogen peroxide. The hydrogen peroxide decay is more significant under UV light for the samples with lower hydrogen peroxide concentrations. Our study also shows the impact of DOC on hydrogen peroxide decomposition is not substantial. The study also presents a modelling method to optimise hydrogen peroxide application based on water quality characteristics. Our findings can provide knowledge for the water industry to produce a suitable model which can be used to optimise the application of hydrogen peroxide for the control of cyanobacteria.


2018 ◽  
Vol 234 ◽  
pp. 03001 ◽  
Author(s):  
Evgeni Dimitrov ◽  
Boyko Gigov ◽  
Spas Pantchev ◽  
Philip Michaylov ◽  
Mihail Peychev

In this paper, a dual-fuel compression ignition engine test bench is presented. In hydrogen-diesel fuel co-combustion conditions, the engine parameters are determined – performance: effective torque, effective power and mean effective pressure; fuel economy: fuel consumption and specific fuel consumption; toxicity: carbon monoxide, carbon dioxide, nitrogen oxides, hydrocarbons, and smoke emissions (opacity). The impact of hydrogen-diesel fuel mass ratio on the performance, toxicity and economy of the engine is studied by obtaining a series of hydrogen-diesel fuel ratio variation characteristics at constant engine speed and load. Improvement of the economical parameters of the engine and reduction of carbon dioxide concentration in exhaust gases is detected under operation with hydrogen gas fuel. Significant reduction of the exhaust gases opacity is observed. It is not clear what the impact of the quantity of hydrogen, injected in the engine, on the concentration of nitrogen oxides in the exhaust gases is.


Author(s):  
В.В. Мурамович ◽  
В.Ю. Каминский ◽  
С.Н. Турусов

Рассматривается экологическая проблема очистки отработавших газов углеводородных энергетических установок от токсичных компонентов. Показан состав основных токсичных компонентов, приведены значения энергии связи их молекул. Представлены существующие методы улучшения экологических характеристик двигателей внутреннего сгорания: рециркуляция отработавших газов, снижение степени сжатия, уменьшение угла опережения впрыска, добавление присадок к топливу и др. Перечислены их достоинства и недостатки. Предлагается новый метод – использование электромагнитных полей для очистки отработавших газов от токсичных компонентов. Выполнен оценочный расчет его эффективности. Показано, что применение устройств модификации в топливной системе двигателей внутреннего сгорания, а также в системе выпуска отработавших газов позволяет существенно снизить выбросы в окружающую среду вредных веществ, и, при этом, не требует принципиальных изменений в конструкции двигателей. Рабочий ресурс предлагаемых устройств электромагнитной обработки обусловлен применяемыми для их изготовления материалами. The ecological problem of cleaning the exhaust gases of hydrocarbon power plants from toxic components is considered. The composition of the main toxic components is shown; the values of the binding energy of their molecules are given. The existing methods of improving the environmental characteristics of internal combustion engines are presented: exhaust gas recirculation, reduction of the compression ratio, reduction of the injection advance angle, addition of fuel additives, etc. Their advantages and disadvantages are listed. A new method is proposed – the use of electromagnetic fields for cleaning exhaust gases from toxic components. An estimated calculation of its effectiveness is performed. It is shown that the use of modification devices in the fuel system of internal combustion engines, as well as in the exhaust gas system, can significantly reduce emissions of harmful substances into the environment, and, at the same time, does not require fundamental changes in the design of engines. The materials used for their manufacture determine the working life of the proposed electromagnetic processing devices.


2017 ◽  
Vol 66 (2) ◽  
pp. 147-168
Author(s):  
Tadeusz Dziubak ◽  
Mateusz Borchet

The sources of atmospheric air pollution are presented. It has been shown that dust is a major component of the intake air of internal combustion engines. The impact of dust on the accelerated wear of the engine components and the influence of T-P-C system wear on engine operation were analysed. The parameters of the air filters are described and defined. The properties of nonwovens and papers, of which filters used in the filtration intake air internal combustion engines of motor vehicles are made, were analysed. Conditions and methodology for testing nonwoven air filter cartridge for passenger cars were developed. A research desk with a particle counter was presented. The results of the study on efficiency characteristics, filtration accuracy and flow resistance for three different filtration rates (three nonwoven cartridges) were presented. There were much smaller levels of efficiency (φw = 92÷98%) and accuracy for nonwoven filter contribution in comparison with paper ones (φw = 95.5÷99.9%). There were observed higher values of the absorbency factor km for nonwoven cartridge (km = 1000÷1300 g/m2) in relation to the paper cartridge (km = 190÷220 g/m2). Keywords: engine, air filter, nonwoven contribution, efficiency and accuracy of filtration, flow resistance, coefficient of dust absorbency, grain size


1987 ◽  
Vol 109 (1) ◽  
pp. 3-35 ◽  
Author(s):  
John B. Heywood

The flow field within the cylinder of internal combustion engines is the most important factor controlling the combustion process. Thus it has a major impact on engine operation. This paper reviews those aspects of gas motion into, within, and out of the engine cylinder that govern the combustion characteristics and breathing capabilities of spark-ignition engines and compression-ignition or diesel engines. Necessary background information on reciprocating engine operating cycles, the primary effect of piston motion and the spark-ignition and diesel engine combustion processes is first summarized. Then the characteristics of flow through inlet and exhaust valves in four-stroke cycle engines, and through ports in the cylinder liner in two-stroke cycle engines are reviewed. These flows govern the airflow through the engine, and set up the in-cylinder flow that controls the subsequent combustion process. The essential features of common in-cylinder flows—the large scale rotating flows set up by the conical intake jet, the creation and development of swirl about the cylinder axis, the flows produced during compression due to combustion chamber shape called squish, flow during the combustion process, and two-stroke scavenging flows—are then described. The turbulence characteristics of these flows are then defined and discussed. Finally, flow phenomena which occur near the walls, which are important to heat transfer and hydrocarbon emissions phenomena, are reviewed. The primary emphasis is on developing insight regarding these important flow phemomena which occur within the cylinder. To this end, results from many different research techniques—experimental and computational, established and new—have been used as resources. It is the rapidly increasing convergence of engine flow information from these many sources that make this an exciting topic with promise of significant practical contributions.


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