Thermal Efficiency Of Diesel Engine Research Articles

Experimental investigations on the performance and emission characteristics of hydrogen enriched Bio-CNG in a common rail direct injection dual fuel diesel engine

The current energy and environmental problems demand the replacement of fossil fuels with renewable fuels. Research shows that hydrogen-enriched CNG fuels enhance the thermal efficiency of diesel engines while reducing gaseous emissions. This experimental work investigates the performance and emissions parameters of a diesel engine in dual fuel mode with hydrogen-enriched Bio-CNG (HBCNG). It is performed on a single-cylinder, four-stroke common rail direct injection (CRDI) diesel engine at 1500 rpm and 3.5 kW. The outcomes of this experiment are compared to a neat diesel operation. It is observed that at low load with 30% gaseous fuel substitution (GFS), brake thermal efficiency decreases by 13.70% and 15.53% for hydrogen and BCNG-enriched diesel, respectively. Similarly, at medium load, with the gaseous mixture of 40% H2 and 60% BCNG co-combusted with 60% diesel, the BTE improves by 15.83%. At high load, 40% gaseous fuel mixture (40% H2 + 60% BCNG) combustion with diesel results in 21.25% enhanced BTE. Moreover, at the same load condition and GFS, emissions of HC increase by 41.59%, CO decreases by 30%, CO2 decreases by 55.36%, and NOx decreases by 25.94%.

Investigation of low carbon emission and high thermal efficiency of diesel engine combined with high-pressure direct injection of hydrogen carrier: Ammonia

Ammonia, as a zero-carbon fuel, has the potential to serve as a medium for the production, transportation, and utilization of clean energy. The scaling up of green ammonia production also necessitates broader utilization channels for ammonia. Applying ammonia as a fuel in engines is an effective way to reduce carbon emissions. This paper employs dual direct injection technology of ammonia and diesel in a novel ammonia-fueled engine to implement various control strategies and investigates their effects on combustion and emission performance. The results indicate that when the ammonia injection timing is advanced from −40°CA ATDC to −60°CA ATDC, the flash boiling of liquid ammonia decreases the indicated thermal efficiency (ITE) below 39% and increases unburned gas emissions. Globally, injecting ammonia during the intake stroke could receive better performance. Split injection strategies of diesel significantly improve the ITE, especially under a higher pilot-injection ratio of 75%. Additionally, increasing the load benefits the ammonia combustion process. Raising the IMEP to 12 bar improves ammonia combustion efficiency to over 95%, with an ITE reaching 49%.

An experimental study on optimum temperature of B20 POBD for higher efficiency and lower emissions of a DI diesel engine in lean and ultra‐lean combustion conditions

AbstractThe impact of inlet fuel temperature on the performance and emission characteristics of a 406 cc, single‐cylinder, air‐cooled, 4‐stroke, direct injection (DI) diesel engine was investigated to determine the suitable temperature of fuel for the best conditions of the engine in lean and ultra‐lean mixture combustion mode. B20 palm oil biodiesel‐diesel blend fuel (B20 POBD), as common renewable fuel and favorite biodiesel blend ratio used in the research, was provided and injected in the engine at varying temperatures in the range of 10–40°C and the engine parameters including the output power, specific fuel consumption (SFC), thermal efficiency, flue gas heat recovery efficiency and CO and NOx pollutant emissions were measured at different air–fuel ratios corresponded to lean and ultra‐lean mixtures. The results showed that there is an optimum temperature for fuel (about 20°C) in which maximum thermal efficiency and minimum SFC and CO emission are obtained. The minimum SFC and CO emission were 0.45 Kg/kWh and 610 ppm at the optimum temperature and output power of 1.5 kW, respectively. The effect of fuel temperature on SFC and CO increases as the output power decreases and for all fuel temperatures, the output power is inversely related to the air–fuel ratio. In addition, the elevated output power reduces the CO emission in all inlet fuel temperatures. Furthermore, an ultra‐lean mixture (very high A/F ratio) can dramatically decrease the thermal efficiency of diesel engines at all fuel temperatures, such that at the inlet fuel temperature of 17°C, increase in A/F ratio from 51 to 108 decreases the thermal efficiency from 16.8% to 0.12%. Finally, low engine output power leads to low levels of NOx emission, such that decrease in output power from 1.5 to 0.5 kW reduces the NOx emission from 522 to 204 ppm, respectively.

Effect of Temperature Variations of Corn (Maize) Oil Biodiesel on Torque Values and Thermal Efficiency of Diesel Engines

The trend of consumption of hydrocarbon fuels in Indonesia, which is increasing every year, is not accompanied by the amount of production, which is decreasing. Alternative fuels to reduce dependence on hydrocarbon fuels. One form of alternative fuel is biodiesel, which is made from corn (maize) oil. Corn oil itself, if processed, can be an option for clean and environmentally friendly energy option and that is the main objective of this research is to determine the performance of biodiesel corn oil on diesel engines. The method used in this study is an experimental method where corn oil biodiesel is tested directly on a testing machine. The data from the test results will be used to find the torque and thermal efficiency values so that the engine performance values for each fuel variation can be identified. The results of the study obtained the engine performance value, namely the highest torque was on diesel oil fuel 4.57 N.m. The highest thermal efficiency value achieved at the B30 fuel sample at a temperature of 60 °C with the thermal efficiency of 17.4 percent. With these results, it can be concluded that engine performance with corn oil fuel can be used as an alternative fuel to replace hydrocarbon fuel.

Model-based Performance Study of Electrically Assisted Turbocharging Diesel Engine

Under the low load conditions, the motor drives the compressor to increase the intake of the engine, and under the high load conditions, the motor recovers the excess exhaust energy, which greatly improves the performance of the diesel engine in all aspects. In this paper, the one-dimensional simulation prediction model of TBD620V16 diesel engine is established and checked. On this basis, the external electric auxiliary turbocharging system of motor is established. The influence of motor power on the performance of diesel engine under different working conditions is studied by simulation, and the control strategy is put forward according to the influence of power and economy of diesel engine under low load. Based on this control strategy, the improvement effect of power performance and economy under low load conditions is studied. The results show that there is an optimal motor power in each load condition to make the comprehensive thermal efficiency of diesel engine reach the maximum value. Under low load condition, with the increase of diesel engine speed, the pressure ratio of electrically assisted turbocharged diesel engine is higher and the fuel consumption is lower. When the diesel engine is accelerated from 25% to 30% load condition, the supercharged pressure of electrically assisted turbocharged diesel engine is stabilized for about 3s, and the supercharged pressure is higher when it is stable, and BSFC is significantly lower than that of traditional turbocharged diesel engine.

Energy Analysis of Diesel Engine With B30 at PLTD Selat Panjang

Many efforts have been made in energy efficiency in power plants. One way to improve the efficiency of energy use is to conduct analysis. The purpose of this study was to analyze the thermal efficiency of a diesel engine with B30 at PLTD Selat Panjang unit 4. The data were collected using a daily operation report log sheet for Caterpillar 3512B diesel with duration 3x24. From the calculation carried out, the average thermal efficiency of diesel engine with B30 as fuel at PLTD Selat Panjang was 47.52%.

Influence of piston bowl geometry on the performance and emission characteristics of a diesel engine operated on single fuel mode using dairy scum oil biodiesel

Contemporary diesel engines required to gratify the strict emission standards without concession of its performance and fuel economy. In view of this condition, effect of various piston bowl geometry on the performance of CI engine and emissions characteristics operated using diary scum oil biodiesel (DSOB) on single fuel mode has been examined. In this experimental study, the challenge was to increase the thermal efficiency of diesel engine using different configurations of piston bowl geometry. To achieve maximum performance and to match adequate piston bowl geometry for existing geometry of nozzle, five types of Piston bowls such as lateral swirl Piston bowl (LSPB), hemispherical, dual swirl Piston bowl (DSPB), re-entrant, lateral and dual swirl Piston bowl (LDSPB) are designed and studied. Study showed that the operation of DSOB with LDSPB provided 10.6% amplified thermal efficiency with 5–26% reduced carbon containing engine gives out gases marginally 25.4% of enhanced levels of NOx when compared to operation of same fuel with other designs of piston bowl.

Performance of diesel engine having waste heat recovery system fixed on stainless steel made exhaust gas pipe

Chemical energy is not effectively converted into mechanical energy by an internal combustion engine. Major portion of heat energy get dissipated with exhaust and coolant. Use of thermoelectric generator (TEG) technology is regarded as an environment friendly technique for recovering the waste heat, with which heat energy directly converts into electrical energy. In this study, an experiment is conducted in which TEG technology has been used to recover waste heat going out through exhaust gas from the diesel engine. Thermoelectric modules were fixed on the surface of stainless steel made pipe having square cross-section. It has been found that the power output of thermoelectric generator enhances with the increase in engine load. The maximum electrical power output of TEG has been obtained as 37 W at maximum load of 6 kg. Overall thermal efficiency of diesel engine has also been improved with the use of TEG type of waste heat recovery system.

Diesel engine waste heat recovery system comprehensive optimization based on system and heat exchanger simulation

Abstract To further improve the thermal efficiency of diesel engines, a waste heat recovery system model utilizing organic Rankine cycle (ORC) is constructed and verified through system bench test and heat exchanger bench test. To recover waste heat from diesel engine exhaust, ethanol, cyclopentane, cyclohexane, R1233zd (E), and R245fa were selected for comparison. The quality of heat source, the quality of evaporator, the system output, and the system complicity were taken as variables for comparison. Analysis shows that for ORC systems without recuperator, ethanol system has the best system output of the five in a wide operation temper range, with the highest exergy efficiency of 24.1%, yet the exergy efficiency increase after the application of recuperator, 9.0%, is limited. For low temperature exhaust, cyclopentane system has the best performance with or without recuperator, and the cyclopentane system with recuperator has the best performance in terms of exergy efficiency, 27.6%, though complex heat exchangers are also required for high power output. The system output of the R1233zd system is better than the R245fa system, yet the advantage of low evaporate temperature can be better utilized for low quality waste heat recovery.

Brake power, brake spesific fuel consumption, dan brake thermal efficiency mesin diesel injeksi langsung berbahan bakar solarjatropa-butanol

Jatropha is proven to reduce dependence on diesel fuel. Jatropha oil is widely used as a mixture of diesel fuel. However, low heating value and high viscosity result in lower engine performance and higher carbon black emissions than pure diesel fuel. Alcohol groups such as butanol have low viscosity properties and oxygen and cetane numbers close to diesel fuel. The use of butanol as an additive to diesel-jatropha mixed fuels is expected to improve engine performance. This study aims to observe brake power, brake specific fuel consumption, and brake thermal efficiency of diesel engines using diesel-jatropha-butanol mixed fuel. Jatropha used 10%, 20% and 30%. While the butanol used is 5%, 10%, and 15% based on volume. The research increased in a brake power value of 2.22%. The decrease in brake specific fuel consumption was 4.81% and the increase in brake thermal efficiency was 10.85%. Keywords : jatropha, viscosity, performance, soot, butanol.

Diesel spray and combustion of multi-hole injectors with micro-hole under ultra-high injection pressure – Non-evaporating spray characteristics

Increasing the injection pressure and reducing the nozzle hole diameters can increase the thermal efficiency of diesel engines (DI). To understand the spray characteristics under ultra-high injection pressure, the spray characteristics of multi-hole injectors with different diameters were investigated under different injection pressures. The results show that the injector with a larger hole diameter has a larger injection delay and a longer injection rate rise and fall time. The injection pressure has a small effect on the injection delay. As the injection pressure increases, the injection rate rise and fall time decreases. Increasing the injection pressure and the hole diameter increases the instability of the spray. The penetration of the injectors with different hole diameters is similar in the initial stage of injection. The penetration increased with the increase of the injection pressure. However, the effect of the high injection pressure on the increase of the penetration becomes weak. The injectors with a larger nozzle hole diameter displayed a larger penetration, spray angle, spray cone angle, and spray area. The micro-hole injector under the ultra-high injection pressure, the expansion of the middle of the spray caused a larger spray angle and spray area. A larger nozzle hole diameter and injection pressure promotes an increase in the gas mass rate. But the injector with the micro-hole diameter has a better ṀA/ṀF ratio and a lower average spray equivalent ratio under ultra-high injection pressure. Naber and Siebers’ penetration model and Inagaki and Mizuta's spray angle model with modified parameters showed the better prediction effect under all experimental conditions.

Study on lean burn limits and burning characteristics of n-heptane with effects of hydrogen enrichment

Lean combustion can be a more effective method to enhance the thermal efficiency of diesel engine, while also face incomplete-combustion and long-combustion duration issues at ultra-lean conditions. Effects of hydrogen, known with wider flame limits and greater burning velocity, on lean burn limits and burning characteristics of n-heptane were studied fundamentally based on optical experiments and chemical kinetics analysis. The results showed that the laminar flame appeared spherically from λ = 0.8 to λ = 1.5 by spark ignition energy of 37 mJ, whereas leaner mixture, λ ≥ 1.6, could only be ignited by 3000 mJ. However, the low ignition energy failed to burn the ultra-lean mixture, while high ignition energy disturbed the flame morphology. The buoyancy appeared near lean-limits due to lower burning velocity and rapid increase of thermal radiation losses. Lean burn limits of n-heptane increased from λ = 1.9 to λ = 4.2 at 393K, λ = 2.0 to λ = 4.3 at 433K and λ = 2.1 to λ = 4.4 at 473K under H2 addition from 0% to 90%. The increasing impact became more significant at H2 ≥ 70%. Besides, as lifting initial temperature, 393–473K, the lean-limits increased 0.2 λ only. With increase of H2, H increased faster than O and OH because more H2 reacted with both O and OH to produce H. CH2O became prominent among C–H–O species, which reacted with H increased rapidly under H2 addition. Consequently, H and CH2O played a substantial role to improve the lean burn limits and burning velocity of n-heptane under hydrogen addition.

Effect of vegetable oil share on combustion characteristics and thermal efficiency of diesel engine fueled with different blends

Diesel engines are one of the most widespread internal combustion engines in the world. However, the requirements of the Environmental saving and decreasing in fossil fuels quality demand on searching the alternative fuel composition, which will be more environmentally friendly. Using different Biofuels allows decreasing the impact on the environment. There are a lot of researches devoted to the investigation of different plant oils as additives to diesel fuel. However, most of them are limited to standard engine parameters investigation. Nowhere was an attempt to evaluate the efficiency of the engine in terms of energy conversion.An experimental investigation has been carried out to analyze the combustion characteristics and thermal efficiency of a diesel engine at constant engine speed fuelled with diesel and its blends (10, 20, 30, 40, and 50%) with linseed oil. The methodology for the determination of the thermal efficiency of the thermodynamic cycle was developed.The results show the effect of the amount of linseed oil in the blends with pure diesel has non-monotonous behavior. The best combustion characteristics and energy conversion efficiency were observed with 20% of the linseed oil share. The worst combination is the blend of 30% linseed oil and of 70% pure diesel. The results mean that the addition of the linseed oil to the fuel mixture has an ambiguous influence on engine performance.

카본 슬러지에 의한 디젤 차량 화재 가능성 연구

Thermal efficiency of diesel engine is higher than that of gasoline engine. But diesel engine requires more strict environmental regulations, due to the pollution. Vehicle manufacturers continue to develope the more efficient devices, reducing detrimental emission gas. EGR system reduces diesel engine NOx and widely used. However, while technological development and improvement of the technology of the exhaust gas abatement device has been made, the side effect increases the vehicle fire. Recent outbreak of fire in a manufacturer's diesel vehicles has surged, and many experts have pointed out that the cause of the fire is a defect in the EGR system and the ignition of carbon sludge attached to the intake system. The structure and the operating principle of EGR system, which is pointed out as the cause of the fire, are investigated and also, the possibility of the fire by the fire recurrence experiment of the carbon sludge is analysed.

Achievement Analysis of One Cylinder Diesel Engine Using Virgin Coconut Oil Biodiesel

Coconut biodiesel is one of the alternative fuels as a substitute for diesel fuel because it can be produced from renewable energy sources, such as virgin coconut oil (VCO). VCO is one of the most potential ingredients as biodiesel feedstock because of its high oil content. Biodiesel from virgin coconut oil in this study produced a transesterification reaction process using CaO catalyst. This study aims to compare the performance of diesel engines “Dong Feng R-175” using biosolar (B5) and virgin coconut oil biodiesel. This study shows that pure coconut oil biodiesel can be used directly in “Dong Feng R-175” diesel engines. The maximum torque of virgin coconut oil biodiesel is 9.81 Nm at 1200 RPM, and the maximum power produced is 1.33 kW at 1700 RPM with specific fuel consumption (SFC) 0.24 kg / kWh. On average, the thermal efficiency of diesel engines “Dong Feng R-175” using virgin coconut oil biodiesel increased by 33.08% compared to using biodiesel B5.

Thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel CI engine at various loads condition

Efforts to find alternative fuels and reduce emissions of CI engines have been conducted, one of which is the use of diesel hydrogen dual fuel. One of the goals of using hydrogen in dual-fuel combustion systems is to reduce particulate emissions and increase engine power. This study investigates the thermal efficiency and emission characteristics of a diesel-hydrogen dual fuel CI engine at various loads condition. The hydrogen was used as a secondary fuel in a single cylinder 667 cm3 diesel engine. The hydrogen was supplied to intake manifold by fumigation method, and diesel was injected directly into the combustion chamber. The results show that the performance test yielding an increase around 10% in the value of thermal efficiency of diesel engines with the addition of hydrogen either at 2000 or 2500 rpm. Meanwhile, emission analyses show that the addition of hydrogen at 2000 and 2500 rpm lead to the decrease of NOx value up to 43%. Furthermore, the smokeless emissions around 0% per kWh were occurred by hydrogen addition at 2000 and 2500 rpm of engine speeds with load operation under 20 Nm.

UJI PRESTASI DAN EMISI DIESEL BERBAHAN BAKAR MINYAK NABATI MURNI UNTUK PEMBANGKITAN DAYA DI DAERAH TERPENCIL

Pure Plant Oil (PPO) such as Pure Coconut Oil (PCO) and Pure Palm Oil (PPaO) could be a solution for electricity problem in remote areas in Indonesia. PCO and PPaO can be used as a fuel for diesel engine to produce electricity. This paper will compare and analyze the performance and emissions of the diesel power plant fueled with diesel fuel, PCO, and PPaO. For performance parameter, brake specific fuel consumption and thermal efficiency of diesel engine by using PPaO and PCO are higher than the diesel fuel, but the brake specific energy consumption are lower than the diesel fuel. That means diesel engine will be more efficient and have lower operational cost by using PPaO and PCO. For the emission parameters, CO2, CO, and CH emissions from PPaO and PCO are higher compared to diesel fuel. That means PPO have higher carbon emission than just using conventional diesel fuel. But, there are highly significant difference of less NOX emissions by using PCO and PPaO compared to the diesel fuel. That means it will be better using PPO because diesel engine has lack of high NOX emissions. These differences of diesel engine performance and emissions by PPaO, PCO, and diesel fuel are caused by the fuel characteristic differences such as cetane number, calorific value, and viscosity.

Advanced combustion free-piston engines: A comprehensive review

A reciprocating engine without a crank-slider mechanism is called a free-piston engine. If the piston is directly connected to a linear alternator, it is called a free-piston linear alternator. Free-piston engines and free-piston linear alternators have the potential to offer solutions for future hybrid electric vehicles and stationary power generation, by enabling direct conversion of mechanical energy to electricity. They benefit from reduced friction losses compared to conventional engines and can have variable compression ratio, which enables combustion control and optimization. Their widespread application has been limited by the necessity for high-speed control strategies. However, their operating characteristics can provide high efficiency, especially when used with low temperature combustion strategies. Low temperature combustion combines the high thermal efficiency of diesel engines, with the low soot emissions of spark-ignition engines, and low NO x emissions because of low burned gas temperatures. This article provides a comprehensive review of free-piston engine technology, with a focus on advanced combustion processes and their potential for use in future powertrain systems.

Effects of injection pressure on ignition and combustion characteristics of impinging diesel spray

The constant injection mass is a criterion for measuring the thermal efficiency of diesel engines. In this study, the effects of the injection pressure on the ignition and combustion characteristics of an impinging diesel spray are investigated for a constant injection mass. Experiments are performed in a constant volume combustion chamber including a high-pressure common-rail injector with a single-hole nozzle. A high-speed camera is used to capture the ignition and combustion behavior. Variation laws for the ignition delay, ignition location, combustion duration, flame area, spatially integrated natural luminosity, and time integrated natural luminosity are obtained by analyzing the images captured in these experiments.

A review on the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends.

Biodiesels have gained much popularity because they are cleaner alternative fuels and they can be used directly in diesel engines without modifications. In this paper, a brief review of the key studies pertaining to the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends, exhaust aftertreatment systems, and low-temperature combustion technology is presented. In general, most biodiesel blends result in a significant decrease in carbon monoxide and total unburned hydrocarbon emissions. There is also a decrease in carbon monoxide, nitrogen oxide, and total unburned hydrocarbon emissions while the engine performance increases for diesel engines fueled with biodiesels blended with nano-additives. The development of automotive technologies, such as exhaust gas recirculation systems and low-temperature combustion technology, also improves the thermal efficiency of diesel engines and reduces nitrogen oxide and particulate matter emissions.