Search

The purpose of the study was to determine the effect of the fuel used in the spark-ignition engine of the selected vehicle on the characteristics of maximum torque and power at the crankshaft of the engine as a function of crankshaft speed and the composition of exhaust gas. The vehicle engine was tested on a stand equipped with V-tech VT-2/B2 chassis dynamometer, MAHA MET 6.3 exhaust gas analyzer and engine parameter monitoring system in compliance with OBD standard. The tests used two commercial fuels with different test octane number (RON) values of 95 and 100 octanes. Measurement of the characteristics of the maximum torque, power on the crankshaft and the total power losses in the drive system, the contact of the wheels with the rollers of the dynamometer and the dynamometer as a function of the crankshaft rotational speed was carried out using the acceleration method with a dynamic load comprising the braking torque of the rotating masses and the electro-swirl brake. On the basis of the test results, engine and drive system parameters of the vehicle, a set of measuring points determining the values of the engine crankshaft speed and the torque generated by the engine crankshaft was determined, using the software for generating driving test runs "the calculation of gearshift points for the WLTC cycle". The parameters of the selected engine operating conditions were within the ranges specified by the software for generating the selected test runs. The content of selected exhaust gas components (carbon monoxide (CO), carbon dioxide (CO2), other hydrocarbons (HC), oxygen (O2), coefficient, nitrogen oxides (NO) and nitrogen dioxide (NO2)) was measured for the selected operating parameters of the vehicle for the tested fuels. On the basis of the results of the toxicity measurements, analytical models determining the content of individual components in the exhaust gases as a function of the crankshaft rotational speed and the torque generated on the crankshaft and software simulating the exhaust emissions of the selected vehicle moving under dynamic conditions were developed. [ABSTRACT FROM AUTHOR]

The object of research is the environmental parameters of a reciprocating engine when using a synthesis gas additive to the main fuel. The research is aimed at solving the problem of reducing the concentration of harmful components in the exhaust gases of an internal combustion engine by adding synthesis gas to the main fuel. Experimentally, the dependences of the effect of the addition of synthesis gas to ethanol on the change in the environmental performance of a piston engine with spark ignition were obtained. The positive effect of the addition of synthesis gas obtained by thermochemical conversion to ethanol in an amount of up to 5 % by weight on the environmental performance of a spark-ignition piston engine was established. Provided that the engine achieves the same effective power, the use of a synthesis gas additive to the main fuel made it possible to reduce the concentration of CO by 61.5 % and CH by 51.3 % in the exhaust gases. no more than 25–30 words The addition of synthesis gas contributed to the formation of radicals that activate oxidation chain reactions, and also made it possible to increase the normal combustion rate of the fuel-air mixture by 6.25 %. This ensures normal engine operation on a leaner fuel-air mixture (α=1.21) without deterioration of environmental, energy and economic performance. no more than 25-30 words The simultaneous reduction of the concentration of harmful components in the exhaust gases and engine efficiency can be achieved by using fuels with a wide concentration limit of ignition and high combustion rate in a lean mixture. The experimental data obtained can be used in the design or modernization of transport and stationary power plants with internal combustion engines as an approach to meet ever-increasing environmental standards. [ABSTRACT FROM AUTHOR]

The paper considers the use of exhaust gas heat in modular power plants. In this regard, fuel consumption at power plants will decrease, efficiency of power plant will increase the emission of harmful gases into the atmosphere and environmental burden will reduce. [ABSTRACT FROM AUTHOR]

To save the environment and utilize the waste heat associated with exhaust gases of internal combustion engines, it is crucial to design an efficient system that can recover this heat loss and convert it into useful energy. This study is devoted to developing, through an experimental approach, a practical technical solution to minimize the waste heat of the exhaust gases and convert it into a source of power for further applications in the vehicle. Six thermoelectric generators (TEG1-1263-4.3) were attached to the exhaust pipe in an arrangement of three connected in parallel and three connected in series. The thermoelectric generators were in a square shape of size 30 mm x 30 mm, and operated at a maximum temperature of 320. The experiments were conducted for a vehicle speed limit between (10 km/h - 60 km/h). It has been found that at a vehicle speed of 55 km/h, the exhaust pipe surface temperature reached approximately 116oC. For six models of TEGs, the output voltage was 4.13 volts. And the system efficiency was found to vary between 3.6% -15.9%, depending on the surface temperature of the exhaust pipe, i.e., the surface temperature that is in contact with the hot side of the thermoelectric generators. Such outputs refer to the efficiency of TEGs to be used as a heat recovery system. Furthermore, the produced power can be used for feeding other applications within the vehicle, such as using a small fridge for a cooling process.

In this study, a second-by-second (SbS) data set obtained from monitoring vehicle emissions over a series of 75 test runs from 2 test vehicles (a conventional vehicle (CV) and a hybrid-electric vehicle (HEV)) over an 18-month period in 2010-2011 during real-world on-road operations on a specified 32-mile route in Chittenden County, Vermont was used in an innovative new method of analysis to assess emissions differences between the two propulsion systems and attribute these differences to physical roadway/infrastructure characteristics. The K-S test was used to assess the difference between the cumulative distributions of the CV and HEV emissions samples on each link, and the K-S test statistic was regressed against the full set of roadway link characteristics. The regression results allowed the team to identify specific roadway characteristics that contribute to emissions differences between the vehicle types. Overall, the models that included maximum grade and intersection control type performed best, however speed limit and horizontal curvature were also shown to be important. The performance differences identified in this project confirm that engine controls that are responsive to roadway characteristics are necessary.View the NCST Project Webpage

One of the key problems of modern engine construction is the improvement of environmental performance while ensuring a competitive price of produced engines. This is achieved using state-of-the-art control systems, expensive fuel equipment, and complex exhaust gas neutralization systems. The search for ways to improve the environmental performance of transport engines without significant complication of their structure is a priority area of modern research. Plasma chemical treatment of gas makes it possible to reduce the level of harmful substances in exhaust gases by 1.5‒4 times relative to operation on propane-butane without processing. This paper considers the possibility of using a plasma dynamic stabilization technique and conducting an electric discharge without contact with metal electrodes for the implementation of endothermic reactions whose implementation requires energy from an external source. During test experiments, volt-ampere characteristics of the system with needle electrodes were established, the distance between which was 2‒5 mm at different feed pressures of propane- butane gas mixture (75 % propane and 25 % butane). At the outlet of the plasma- chemical reactor, a hydrogen-containing gas mixture is obtained, which is subsequently supplied to the combustion chamber through the regular gas fuel system of the engine. Next, when such a gas mixture burns in the combustion chamber, hydrogen acts as a catalyst for chemical reactions, which reduces the thickness of the flame extinguishing front, increases the speed and completeness of combustion of the gas mixture. Based on the results of comparative motor studies, it was found that plasma-chemical treatment of propane-butane has almost no influence on the effective efficiency of the engine and specific fuel consumption. It should also be noted that the use of plasma- chemical reactors on board a vehicle allows them to be integrated into regular gas fuel engine systems with minimal changes in their structure, which has almost no effect on the mass-size indicators and maintenance conditions of the gas fuel system. [ABSTRACT FROM AUTHOR]

The authors propose the use of ultrasonic radiation to clean the exhaust gases of internal combustion engines of the solid particles. An experimental stand and research results are presented, proving the possibility and efficiency of using the process of ultrasonic cleaning of exhaust gases due to the process of the solid particles coagulation. The authors received a corresponding patent, the efficiency of which has been proven by results of the conducted research. [ABSTRACT FROM AUTHOR]

The energy transition from fossil fuels to renewable fuels is constantly developing and implementing. It is the subject of worldwide research, seeking to curb climate change and the negative effects of pollution. An economic sector worldwide that generates a large amount of pollutants is the transport sector, which only uses fossil fuels. Accordingly, it is necessary to test renewable alternatives that reduce the pollution caused by the sector, trying to use the current automotive fleet. The purpose of this paper is to show the effects of the direct injection of hydrogen gas obtained using an alkaline electrolysis system in a single-cylinder internal combustion engine operated with Diesel fuel, managing to study the effects of hydrogen injection on the different engine parameters such as fuel consumption, rpm, torque, temperature, and exhaust gas analysis, performing a statistical analysis that allows determining the input variables that most influence the decrease in polluting gases CO and CO2 and the variation in fuel consumption in addition to engine performance. [ABSTRACT FROM AUTHOR]

Waste heat recovery for meeting the air conditioning demand of a ship is reported. An absorption refrigeration system is proposed. Water-LiBr is used as the working pairs for this purpose. A steady-state energy, exergy, and environmental analysis is done to compare the proposed system with the conventional system. Exhaust gases of auxiliary engines are used to vaporize high-pressure water. High-pressure steam is employed as a heat source for the generator of the absorption system. The results show that exhaust gases of the auxiliary engine as a permanent heat source suffice for the generator of the absorption system. For tropical conditions, the required power for the absorption system is much lower than that for the conventional system. (W ̇ demand for the absorption system is 0.02, while it is 88.28 for the conventional system). The second law of thermodynamics shows a 31% lower total irreversibility in the proposed system versus the conventional system. The use of the absorption system causes a USD 45,078 saving in the yearly penalty cost of CO2 emission. [ABSTRACT FROM AUTHOR]

A significant jump in the development of machine building technologies requires the adjustment of environmental indicators. The main sources of air pollution are vehicles with internal combustion engines. According to research data, the main share of toxic emissions is accounted for by the engine idle mode and constant load mode. Studies carried out to improve fuel efficiency of diesel engines which have been in operation for some time show the potential for increasing the efficiency by deactivating a portion of the cylinders. At the same time, the improvement of efficiency indicators varies within a wide range - from 4 to 30%. The larger the number of deactivated cylinders, the higher the fuel economy effect, but as the effective power increases, it is advisable to reduce their number. The potential for increasing efficiency by deactivating a portion of the cylinders is incorporated in all diesel engines in operation. The efficiency of cylinder deactivation is confirmed by experimental data obtained on various types of engines, including automobile, tractor, diesel locomotive, and ship engines. This method is known in engine building primarily as a means of increasing the efficiency of diesel engines at idle speed and small loads. It has been established that there is a decrease in the hourly fuel consumption to 33% of the rated effective power when engine cylinders are deactivated compared to operation without cylinder deactivation. A diesel engine was tested on a running-brake stand fitted with the necessary measuring and recording equipment and instruments, allowing for a maximum torque of 363 N·m at the crankshaft speed within 1200–3000 min−1. Our studies covered three engine operation options. It has been established experimentally that the specific indicator fuel consumption in the second mode, as compared to the first mode, decreases to 9% due to a decrease in the hourly fuel consumption at the speeds from 1600 min−1 to 2350 min−1. In the third mode, fuel economy at idle speed with a shutdown of the fuel supply and the drive of the gas distribution mechanism of the 2nd and 3rd cylinders was about 24% at the engine shaft speed in the range from 1200 min−1 to 2350 min−1. Upgrading the diesel engine using an electromagnetic fuel valve will pay itself off in about a year. A comparison of the experimental and theoretical data shows that their discrepancy in the whole range of the engine crankshaft speeds does not exceed 7%. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to examine the toxicological impacts of exhaust generated during the combustion process of aviation fuel containing synthesized hydrocarbons. Design/methodology/approach: Tests on aircraft turbine engines in full scale are complex and expensive. Therefore, a miniature turbojet engine was used in this paper as a source of exhaust gases. Toxicity was tested using innovative BAT–CELL Bio–Ambient Cell method, which consists of determination of real toxic impact of the exhaust gases on the human lung A549 and mouse L929 cells. The research was of a comparative nature. The engine was powered by a conventional jet fuel and a blend of conventional jet fuel with synthesized hydrocarbons. Findings: The results show that the BAT–CELL method allows determination of the real exhaust toxicity during the combustion process in a turbine engine. The addition of a synthetic component to conventional jet fuel affected the reduction of toxicity of exhaust gases. It was confirmed for both tested cell lines. Originality/value: In the literature related to the area of aviation, numerous publications in the field of testing the emission of exhaust gaseous components, particulates or volatile organic compounds can be found. However, there is a lack of research related to the evaluation of the real exhaust toxicity. In addition, it appears that the data given in aviation sector, mainly related to the emission levels of gaseous exhaust components (CO, Nox and HC) and particulate matters, might be insufficient. To fully describe the engine exhaust emissions, they should be supplemented with additional tests, i.e. in terms of toxicity. [ABSTRACT FROM AUTHOR]

We have devised a scheme for the energy-generating unit based on the internal combustion engine 1Ch 6.8/5.4 with a spark ignition and a two-stage system for the recovery of heat from the exhaust gases. The basic elements for the first and second stages of the heat recovery system have been selected. A first stage involves a rotary piston expansion machine while a second stage employs the fuel conversion. We have studied effective parameters for the engine 1Ch 6.8/5.4 with a system of the deep two-stage recovery of heat from exhaust gases under different modes of operation. The dependences were established for change in the specific effective fuel consumption on the power of the energy-generating installation using only the conversion of fuel and in a combination with the expansion machine. The dependences have been derived for the operational parameters of a rotary piston engine on consumption of a working body. We have determined temperatures of the working bodies in a reactor and the heat capacity of exhaust gases depending on the load on the engine, as well as the necessary amount of energy to convert ethanol into synthesis gas. The dependences have been obtained of the degree of ethanol conversion on the reaction temperature and the mass flow rate through the reactor. We have established the dependence of specific heat of the chemical reaction on the degree of conversion. It was established that when reaching full conversion in line with the reaction of decomposition the entire liquid ethanol is completely converted into combustible synthesis gas, whose main components are hydrogen, carbon monoxide, and methane. The estimated specific lower combustion heat of the synthesis gas is 28.79 MJ/kg. Obtaining 1 kg of synthesis gas requires 4.0 MJ of thermal energy. It was determined that under condition of applying the conversion of fuel and, accordingly, the addition of synthesis gas, the specific effective ethanol flow rate, depending on the mode of engine operation, decreases by up to 12 %. The amount of energy that needs to be used in the reactor for obtaining synthesis gas is 50…65 % of the heat released with the exhaust gases under a given mode of operation. It has been established that the application of a rotary-piston expansion machine that acts as the first stage in the recovery of heat from exhaust gases has made it possible to gain an increase in the capacity of the energy-generating unit of 27 %. It has been found that the use of two stages of heat recovery leads to a decrease in the specific effective fuel consumption by 29 % [ABSTRACT FROM AUTHOR]

Hydrogen as potential engine fuel can appear either as a single gas or as a component in processing gases e.g. syngas, hythane and coke gas. The research in this paper investigates impact of combustible mixture dilution on abnormal combustion called knock in the reciprocating internal combustion engine. Dilution can be realized by either exhaust gas recirculation (EGR) or making the combustible mixture lean. Novelty of this work is a new metrics defined as dilution ratio, which makes it possible to compare knock reduction caused by either EGR or leaning the air-gas mixture to the engine. Two gaseous fuels were investigated: hydrogen and coke gas with 65% hydrogen. Conclusion based on the proposed dilution ratio states that, for hydrogen as the fuel, applying EGR is more effective in knock reduction than making the mixture lean. It was found that EGR strategy in the hydrogen fueled engine can reduce knock intensity from initial 40 kPa–20 kPa, whereas by leaning the mixture to the same dilution ratio, the knock is reduced to approximately 28 kPa. With respect to coke gas, it is proved that both EGR and lean mixtures influence on knock reduction at the same strength. • Combustible mixture dilution impact on combustion knock intensity. • Dilution ratio as a metrics for both exhaust gas recirculation and lambda. • Engine knock reduced more effectively by applying exhaust gases recirculation. • The correlation between dilution ratio and knock intensity is almost linear. [ABSTRACT FROM AUTHOR]

Highlights • An improved WSGG model suitable for the exhaust gases of aero engines is proposed. • The effects of temperature and pressure are included in the improved model. • Comparison between the improved model and existing models is conducted. Abstract Advanced aero engines operate at high temperatures and pressures to improve thermal efficiency and power output, thus thermal radiation becomes a significant mode of heat transfer for exhaust gases. The existing gaseous radiative models for atmosphere are not suitable for the application in aero engines due to the huge pressure variation of exhaust gases. In this work, an improved weighted sum of gray gases (WSGG) model for mixtures of H 2 O and CO 2 within broader ranges of temperature and pressure variations is proposed. The mole ratio of H 2 O and CO 2 is fixed at 1/1, which represents typical products of stoichiometric combustion of kerosene. The weighting factors, which only relate to the temperature in previous WSGG models, are modified by taking into account the effects of both temperatures and pressures. The coefficients of the improved WSGG model are obtained based on the up-to-date HITEMP-2010 database, and they are valid for the temperatures varying from 500 K to 2500 K, pressures ranging from 1 atm to 30 atm, and pressure path-lengths ranging from 0.0001 atm·m to10 atm·m. To access the accuracy of the coefficients, the improved WSGG model and other two traditional WSGG models are applied to the solution of the radiative heat transfer with the discrete ordinate method, and the comparison is conducted with the benchmark line-by-line calculations. The results indicate that the improved WSGG model has much higher accuracy in the simulation of gaseous radiative heat transfer for exhaust gases of aero engines. [ABSTRACT FROM AUTHOR]