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Compression-Ignition Engine Combustion
Published in Kenneth M. Bryden, Kenneth W. Ragland, Song-Charng Kong, Combustion Engineering, 2022
Kenneth M. Bryden, Kenneth W. Ragland, Song-Charng Kong
Diesel engines follow the same four-stroke cycle as SI engines. The primary difference is that ignition of the fuel in a diesel engine is by compression, and there is no spark plug. Some diesel engines have glow plugs for cold starting. In the ideal thermodynamic cycle, diesel combustion occurs at constant pressure, whereas combustion in the Otto cycle occurs at constant volume. In practice for both types of engines, the pressure and volume change during combustion. Diesel engines, similar to SI engines, have a higher thermal efficiency at an increased compression ratio. The compression ratio in SI engines, which burn premixed fuel and air, is limited by abnormal knocking combustion. Diesel engines, which have direct injection of liquid fuel into each cylinder, do not experience knock and thus can have a higher compression ratio than SI engines. Whereas diesel engines may have compression ratios between 12 and 18, the compression ratio in SI engines is limited to about 10. In addition, diesel engines control load (power output) by reducing the amount of fuel injected into each cylinder. By contrast, SI engines restrict the air and the fuel at part load by means of a throttle so as to maintain a stoichiometric mixture over all loads. The throttle increases the pressure loss during the intake stroke, increasing pumping loss and reducing the net thermal efficiency of the SI engine.
Portable Power Generators
Published in Richard Cadena, Electricity for the Entertainment Electrician & Technician, 2021
There are many different types of generators and prime movers, but most of the ones used for live event production are diesel-powered. Diesel engines have a turbocharger that forces a mixture of air and exhaust gases into the combustion chamber of the engine to increase its efficiency. Because the exhaust gases are very hot, the turbocharger gets very hot, so the engine should be idled before shutting it off in order to allow the operating temperature to drop. Unless there is an emergency, the engine should never be turned off without idling it first; otherwise, the bearings in the turbocharger could seize. At the end of the day, when the generator is no longer needed, turn off the circuit breaker and disconnect the cables while the generator is idling and let it idle for five or ten minutes before turning it off.
Road-Traffic Emissions
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Air Quality and Energy Systems, 2020
Fabian Heidegger, Regine Gerike, Wolfram Schmidt, Udo Becker, Jens Borken-Kleefeld
As previously mentioned, kinetic energy is generated in either a combustion or an electric engine. Electric engines have a higher degree of efficiency than combustion engines. A hybrid vehicle obtains its energy from an electric engine and a fuel-based engine. Combustion engines are characterized by a cyclic, non-stationary, and non-optimal combustion process (Pfäfflin 2018). For a comparable vehicle type with similar engine power, the diesel engine has an advantage in terms of fuel consumption as compared to the gasoline engine. The spark ignition of the diesel leads to a more energy-efficient yield of fuel: This combustion process results in less fuel consumption and lowers CO2 emissions; however, rising combustion temperatures lead to greater NOx emissions.
Straight vegetable oil fuel performance and exhaust emissions under turbocharged and naturally aspirated conditions
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Albert K. Sunnu, Godwin K. Ayetor, James M. Gaye
The viscosity and density of vegetable oils have been known to be higher than petroleum diesel (Kumar and Gakkhar 2018; Sonthalia and Kumar 2017). Lower calorific values of vegetable oils have been the cause of inferior engine performance such as power, torque and engine efficiency (Mat et al. 2018). These properties affect vaporization, atomization and fuel mixing in the combustion chamber (Yilmaz, Atmanli, and Vigil 2018). Many researchers have reported injector coking, filter plugging, and injection pump failure with vegetable oil usage in direct combustion engines (Capuano et al. 2017). There are little investigations comparing the effect of a turbocharged engine and a naturally aspirated engine run on vegetable oils. This will provide answers on whether the performance of a vegetable oil-run engine could be improved by employing a turbocharger. The turbocharger is commonly employed in diesel engines to improve efficiency. A turbocharger is used to increase power by pumping additional compressed air into the combustion chamber (Halderman and Mitchell 2014). This allows more fuel, which would have otherwise gone waste, to be burned to release more power (Mashadi and Crolla 2011). Exhaust gas is used to spin the wheel of the turbocharger which drives the turbine blades. The turbine allows air to be pumped into the intake system by spinning the compressor.
The combined effect of multiwalled carbon nanotubes and exhaust gas recirculation on the performance and emission characteristics of a diesel engine
Published in International Journal of Ambient Energy, 2019
Anchupogu Praveen, G. Lakshmi Narayana Rao, B. Balakrishna
Environmental pollution caused by the combustion of fossil fuels has been creating an impact on the environment and human life. The contribution of the petroleum-based fuels does not meet the current demand of energy due to increased automobiles utilisation in the transportation sector (Jayed et al. 2009). Diesel engines are more advantageous because of their higher efficiency, fuel economy, reliability and durability. But diesel engines emit various pollutants (such as CO, CO2, HC, NOx and smoke emissions) into the environment, creating air pollution (Khalife et al. 2017). The NOx emissions from diesel engines create harmful effects on the environment and human health. The NOx emissions were reduced by adopting after treatment technologies like exhaust gas recirculation (EGR), Selective catalytic reduction (SCR), Lean NOx Trap (LNT) and SCR Filter (SCRF) (Devarakonda, Parker, and Johnson 2008).
The empirical correlation between the parameters influencing the performance and emissions of CI engine run by aqueous nanofluid fuel blends using response surface methodology
Published in Petroleum Science and Technology, 2022
Sorakka Ponnappan Venkatesan, Kadiresh Parthasarathy Natarajan, Jeya Jeevahan Jayaraj
The diesel engine is more efficient, better in fuel economy, and emits a lower rate of unburnt hydrocarbon and carbon monoxide compared to the petrol engine. Diesel engines are used in various sectors such as transportation, marine propulsion, power generation, agricultural and industrial application. When diesel engines are vastly used, it could result in an increase in the emissions i.e., NOX, particulate matter, smoke, and soot which affect the environment to a large extent. India's oil utilization is around 4,990,000 barrels per day and it is placed 3rd in the world of oil-consuming countries. The pollution control research association says that more than 50% of the entire oil consumption is used by the transport sector. The contribution of the transport sector to environmental pollution is very large and of these pollutants, CO is the main pollutant followed by the emission of hydrocarbons. In India, the transport sector discharges approximately 261 tons of CO2, of which 94.5% is provided by road transport. 60% of the greenhouse gas staging represents the transport sector. Air pollution is a threat to public health and is also considered exasperation. On average, a man breathes 22,000 times and inhales 35 pounds of air each day. The health effects due to poor air quality are eye pain, impaired lung function, decreased inattention to infection, increased incidence and severity of lung cancer, reproductive problems, birth defects, and premature death, mainly due to respiratory and cardiac conditions. The fossil fuels are steadily draining day by day and stringent emission legislations are formed on IC engines are the driving forces for finding fuel sources with better specific fuel consumption and emissions reduction characteristics. Combustion system design and quality of fuel are the important factors in emissions formation. Many improvements in the design of combustion systems have reduced emissions (Yun et al. 2013; Yuan et al. 2014; Yasuda et al. 2016; Ganesan et al. 2019; Vos et al. 2019)