Efficiency Of Diesel Engine Research Articles

Prediction of split injection strategy assisted diesel engine combustion, performance and emission characteristics fuelled waste frying oil methyl ester through central composite design

The objective of this study is to use response surface methodology to forecast the performance, combustion, and emission characteristics of an advanced injection strategy-assisted diesel engine running on waste frying oil methyl ester. The experiment was carried out on a diesel engine using a high-pressure fuel injection system. The main injection timing ranges varied from 16 to 24 °CA bTDC, whereas the post-injection ranges from −6 °CA bTDC to 6 °CA aTDC. The injection quantity for the main and post injections quantity varied from 70 % to 90 %, 10 % to 30 %, and the injection pressure is set at 500 bar. Experiments were carried out using a design matrix developed by the design of experiments. At 100 % load, B100-90 %-10 % obtained the highest BTE of 33.87 % and the lowest fuel consumption of 0.268 kg/kW-hr. At the main injection timing of 22 °CA and post-injection timing of −4 °CA, D100-80 %-20 % achieved the lowest unburned hydrocarbon, Smoke emission of 13 ppm, and 1.613 FSN respectively. The point prediction approach was used to forecast the combustion and emission parameters of a diesel engine, and the predicted results were in good agreement with the experimental results. Furthermore, when compared to advance injection timing for biodiesel fuel, retarded injection timing reduces nitric oxide emission. The Split injection strategy is one of the most effective techniques to reduce soot and NO × emissions while maintaining diesel engine efficiency.

Study on Cu Based Organic Linkers for Effective Emission Control over Diesel Engine Effuluents

The Cu-MOF has outstanding catalytic activity because of its capacity to buffer oxygen. As a result, when added to diesel fuel, this additive reduces nitrogen dioxide emissions while also oxidising hydrocarbon emissions. The current study examines the impact of Cu-MOF nanoparticles on diesel engine efficiency and emissions. The SEM, and XRD methods were utilised to characterise the nanoparticles of Cu-MOF, which were generated by chemical approach. In a two-step method, Cu-MOF was combined with diesel using a conventional ultrasonic shaker in order to get a stable suspension, Extensive experiments using ASTM-standard testing procedures have also examined the impact of nanoparticles on several physicochemical parameters of diesel fuel. For the purpose of examining the impact of nanoparticles on engine efficiency and emissions, a diesel engine load test was conducted. Also included are side-by-side comparisons of fuel qualities with and without additives.

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%.

Modeling and Grey Relational Multi-response Optimization of Chemical Additives and Engine Parameters on Performance Efficiency of Diesel Engine

Singular optimization of engine conditions for better engine performance have been studied extensively. However, in the practical sense, more than one performance characteristics are essential in the optimization of engine conditions. The current study investigates the effect, optimization, and modeling of engine conditions on multi-characteristics of a single cylinder-dual direct injection-water cooled diesel engine with the help of Taguchi-grey relational and regression analyses. The engine conditions employed are engine load, hydrogen, multi-walled carbon nanotubes (MWCNTs), ignition pressure, and ignition timing, at four different levels. The engine performance characteristics analyzed were brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), hydrocarbons (HC), nitrogen oxide (NOx), carbon monoxide (CO), and carbon dioxide (CO2). The results showed that there was a similar behavioral pattern of the effect of engine conditions on engine performance, except for ignition timing. The optimal settings for better engine performance were obtained at 25% engine load, 20% hydrogen, 50 ppm MWCNTs, 220 bar ignition pressure, and 21 obTDC ignition timing. Interestingly, the discovered optimal did not fall within the considered experimental runs, however, the predicted optimal engine performance was within 95% confidence bounds. It is recommended that the experimental work based on the obtained optimal settings should be conducted to elucidate the efficacy of the confirmation analysis. The analysis of variance showed that the engine load was the most significant factor on the overall engine performance, having a contribution of 71.47%, followed by hydrogen and MWCNTs. Also, the ignition pressure and timing were not significant on the overall engine performance, which showed a need to place more attention on the significant factors for better engine performance. The mathematical and graphical modeling showed the efficacy of the design analysis, while the interaction plots showed broader detailed factor settings for better engine performance.

About the possibility of using natural gas as a fuel on agricultural tractors

AIMS: Evaluation of the effectiveness of converting diesel engines used in agricultural self-propelled vehicles to fully or partially natural gas (methane) fueled engines.
 METHOD: Is analytical.
 RESULTS: In agriculture up to 25% of operating expenses are fuel costs. However, the only number of the concomitant objective and subjective factors allow us to estimate expedience and efficiency of converting diesel engines used in agricultural self-propelled vehicles for full or partial supply of natural gas (methane). On the one hand, the price of an equivalent amount (in terms of work performance) of natural gas is more than 2 times lower than the price of diesel fuel. At the same time, natural gas is the most environmentally friendly hydrocar-bon fuel. But, on the other hand, the underdeveloped refueling infrastructure is obvious, and the environmental friendliness of natural gas itself is not a guarantee of the environmental friendliness of the engine itself. Also, the safety of gas equipment operation under high pressure is an important matter.
 CONCLUSIONS: Firstly, the use of natural gas instead of diesel fuel requires taking into account the difference in the physicochemical characteristics of these fuels, which determines both the requirements for the organization of the working process and the advantages and disadvantages of such replacement. Secondly, the combustion process of natural gas, compared to diesel fuel, is characterized by in-creased formation of water leading to more intensive watering of lubricating oil, although it re-duces carbon dioxide emission into the atmosphere. Safety of natural gas equipment operation plays an important role, and first of all, it is concern of cylinders that are filled at pressure of 20.025.0 MPa.

Prediction of cavitation inside mini-sac Diesel injector nozzle using computational fluid dynamics

Fuel injector nozzle is important part of fuel injection system which plays dominant role in spray formation which directly and indirectly affects on combustion efficiency of diesel engine. The performance of the internal flow of the fuel injector nozzle is impeded by several factors. Cavitation is one of the factor which affects fluid flow. It is associated with local pressure distribution inside nozzle. Therefore cavitation plays major role while designing injector nozzle. In the present study, analysis of existing six hole mini-sac diesel injector nozzle is carried out using commercial CFD package. The main objective of research is to design of nozzle to avoid cavitation and to find out contribution of different parameters through parametric study. The results are predicted and compared with both test result and analytical result at steady state conditions for different needle lift., the better the results.

Life-cycle CO2 mitigation of China’s class-8 heavy-duty trucks requires hybrid strategies

•No near-term silver bullet: target the right technology for the right duty-cycles •Efficient diesel engine, battery-electric, and hydrogen fuel cell can enable >38% GHGs reduction •Advanced trucks paired with low-carbon energies can reduce >70% life-cycle GHGs •Hybrid strategies are required for an orderly, effective, and efficient HDT decarbonization China has committed to peaking its CO2 emissions by 2030 in order to achieve its 2060 carbon neutrality target. Heavy-duty trucks (HDTs) are an important area to decarbonize, given the continuously rising greenhouse gas (GHG) emissions in this sector. Various low-carbon options have emerged, yet a comprehensive understanding of the extent to which these options can decarbonize HDT throughout the life cycle remains limited. Here, we adopt a life-cycle analysis to assess and compare the GHG mitigation potential ofhighly efficient diesel engines, battery-electrics, and hydrogen fuel cells for China’s class-8 HDTs in 2030. Results show that all three options could enable >38% life-cycle GHG reductions. The battery-electric option, however, requires well-established fast-charging infrastructures to maintain the freight-carrying capacity that will otherwise be compromised by larger batteries. Hydrogen fuel cells can attain 80% reduction when paired with low-carbon hydrogen. Hybrid strategies, including improving engine efficiency, decarbonizing power grids, optimizing freight logistics, and incentivizing behavioral changes, are necessary for the efficient and effective HDT decarbonization that is key to China achieving carbon neutrality by 2060. China has committed to peaking its CO2 emissions by 2030 in order to achieve its 2060 carbon neutrality target. Heavy-duty trucks (HDTs) are an important area to decarbonize, given the continuously rising greenhouse gas (GHG) emissions in this sector. Various low-carbon options have emerged, yet a comprehensive understanding of the extent to which these options can decarbonize HDT throughout the life cycle remains limited. Here, we adopt a life-cycle analysis to assess and compare the GHG mitigation potential ofhighly efficient diesel engines, battery-electrics, and hydrogen fuel cells for China’s class-8 HDTs in 2030. Results show that all three options could enable >38% life-cycle GHG reductions. The battery-electric option, however, requires well-established fast-charging infrastructures to maintain the freight-carrying capacity that will otherwise be compromised by larger batteries. Hydrogen fuel cells can attain 80% reduction when paired with low-carbon hydrogen. Hybrid strategies, including improving engine efficiency, decarbonizing power grids, optimizing freight logistics, and incentivizing behavioral changes, are necessary for the efficient and effective HDT decarbonization that is key to China achieving carbon neutrality by 2060.

Effect of assisted hydrogen on combustion and emission characteristics of a diesel engine fueled with biodiesel

In this paper, the effects of hydrogen assisted biodiesel with different fatty acid methyl esters (FAMEs) proportion on cylinder pressure, cylinder temperature, indicated thermal efficiency (ITE), NOx emission, HC emission and CO emission of a marine medium speed diesel engine are studied. The corresponding CFD model is executed by CONVERGE coupled to CHEMKIN, and a chemical kinetic mechanism with 314 reactions and 98 species is developed to accurately simulate the fuel injection and combustion processes. The results show that cylinder pressure, cylinder temperature and ITE increased with increasing HEF. Compared with rapeseed methyl ester (RME) and cottonseed methyl ester (CSME), the cylinder pressures are increased by 16.39% and 16.30% for CSME-6%H2 and RME-6%H2 at 100% load, respectively. The cylinder temperatures are increased by 7.42% and 7.14%, and ITE increased by 3.73% and 3.9%, respectively. In addition, the HC and CO emissions decreased significantly with the increase in HEF, while NOx emission increased. Compared with pure CSME and RME, HC emissions are reduced by 70.97% and 72.22% for CSME-6%H2 and RME-6% H2, and CO emissions are reduced by 41.89% and 38.12% for CSME-6%H2 and RME-6% H2 at 100% load, respectively. Overall, the strategy of using CSME-6% H2 mixed fuel for engine is not only economical and practical, but also can prevent performance loss and reduce emissions.

Investigation of future low-carbon and zero-carbon fuels for marine engines from the view of thermal efficiency

The use of low-carbon and zero-carbon alternative fuels on marine engine is the main measure to achieve carbon neutrality for shipping sector, thus attracting numerous research on fuel techno-economics, fuel safety and fuel production chains. However, among the factors that determine whether a fuel can finally be successfully marketed, the thermal efficiency of the fuel is very important as one of the cores in determining the operation cost. To evaluate the thermal efficiency of marine alternative fuels, a new theoretical engine cycle, Miller–Sabathe cycle, is proposed to identify thermal efficiency optimization potential of fuels under certain constraints. The Miller–Sabathe cycle can simultaneously optimize the combustion process and gas exchange process, offering a more comprehensive comparison of fuel thermal efficiency. Compared with technologies based on specific engine design or operation conditions, the Miller–Sabathe cycle analysis provides broader thermal efficiency optimization guidance, and is easy to generalize to different types of engines under different operating conditions. Based on the Miller–Sabathe cycle, a zero-dimensional model is built to further consider the influence of actual losses on thermal efficiency. Then the brake thermal efficiency of various alternative fuels under the Miller–Sabathe cycle is compared using a marine two-stroke diesel engine specifications. The theoretical Miller–Sabathe cycle analysis results shows that under a certain Miller cycle strength and an appropriate ratio of constant volume combustion, the maximum thermal efficiency is capable to increase to 71.17%. The results of 0-D model suggests that the brake thermal efficiency of the marine diesel engine is capable to reach 53.09% by balancing the power performance and actual losses. At last, the results of the alternative fuels calculation suggests that among several alternative fuels, the overall thermal efficiency of ammonia has significant advantages, which makes it a very economical zero-carbon fuel. These results may contribute to the future design of low-carbon emissions and high thermal efficiency engines.

Performance, emission and combustion characteristics of a diesel engine fuelled with diesel/coconut shell oil blends

In this work the coconut shell oil (CSO) - diesel blends are utilized in a compression ignition (CI) engine and its performance, combustion and emission behaviour are analysed with different loading conditions. The coconut shell oil is extracted from coconut shells by the pyrolysis method conducted in an oxygen-free environment with different processing temperatures. The extracted fuel was tested in a single-cylinder, four-stroke, direct-injected (DI) diesel engine with different diesel/coconut shell oil blends (CSO20, CSO40, CSO60, CPO80 and CSO100). During the experimentation, the engine was operated with a constant speed of 1500 rpm and an injection pressure of 250 bar at 23 deg before TDC. The result of this study is clearly showing that the neat coconut shell oil and its blends could be used effectively in diesel engines with better thermal efficiency and exhaust pollutants. It is found that the total fuel consumption by the diesel engine is increased with the presence of CSO in the blends. The blend of CSO20 has registered a lower fuel consumption rate compared to other blends, due to its high heating value. The brake thermal efficiency (BTE) of diesel engines operated with CSO and its blends have registered lower values compared to diesel fuel. The blend of CSO20 has resulted with high heat release rate (HRR) and in-cylinder pressure compared to other blends. The exhaust pollutants like carbon monoxide, hydrocarbon and smoke from CSO blends were registered at different values based on the presence of CSO in the blends. The blend of CSO20 has produced lower pollutants compared to other blends, which is nearer to the values of diesel fuel. The blends of CSO80, and CSO100 produced lower NOx emissions compared to neat diesel and other blends.

RETRACTED: Exploration over combined impacts of modified piston bowl geometry and tert-butyl hydroquinone additive-included biodiesel/diesel blend on diesel engine behaviors

Nowadays, the use of biodiesel for diesel engines has been attracting researchers aiming to improve engine characteristics although the engine performance could be decreased while utilizing biodiesel. In this aspect, optimizing the piston bowl geometry is one of the useful approaches to enhance the efficiency of the biodiesel-powered diesel engine. In this study, the standard piston of an existing diesel engine was modified into two different combustion bowls, namely Symmetrical Stepped Curved-V (SSCV) and Symmetrical Spline-V (SSV), to evaluate the CI engine performance powered with mixtures of sesame-originated biodiesel, diesel fuel, and tert-butyl hydroquinone (TBHQ) additive through two-stage experiment. In the first phase, experiments were carried out on two modified piston bowls powered by diesel and S20 (20% sesame biodiesel + 80% diesel fuel). Resultantly, SSV piston revealed superior engine characteristics to SSCV piston and standard piston due to enhanced air–fuel mixing and more complete combustion of SSV piston-based engine. Indeed, SSV piston operation exhibited an 8.68% of increased brake thermal efficiency (BTE), 6.54% of curtailed brake-specific fuel consumption (BSFC), 4.76% of lowered carbon monoxide (CO), 4.84% of decreased unburnt hydrocarbon (HC), and 2.22% of lowered smoke opacity but with increased nitrogen oxide (NOx) by 14.14% in comparison to diesel. In the 2nd phase, to control the NOx emission effectively, a TBHQ additive was added to the S20 sample at different proportions (500 mg and 1000 mg) to analyze the test engine behaviors with modified piston shapes. As a result, S20 + 500 mg TBHQ at 100% load improved BTE by 5.79% and reduced BSFC by 4.36% in the case of SSV piston. Moreover, it curtailed emissions of CO, HC, NOx, and smoke opacity by 13.33%, 15.49%, 12.09%, and 9.44%, respectively, when equated with diesel. Overall, S20 + 500 mg TBHQ could be thought of as a possible alternative fuel on SSV piston as it resulted in superior performance and emission characteristics in the existing standard engine. The current study's findings could pave the way for the development of diesel engines with modified piston geometry that is more efficiently compatible with biodiesel blends and additives.

Multidimensional Computational Fluid Dynamics Combustion Process Modeling of a 6V150 Diesel Engine

Abstract The smart diesel program requires the engine electronic control unit to consider additional parameters, such as altitude and climatic conditions, in the mapping calibration process. A specially designed environmental simulation cabin, which can simulate environmental conditions at any longitude and dimension, would allow dynamometer testing to be performed indoors. Considering its high cost, a three-dimensional (3D) computational fluid dynamics (CFD) is needed to guide and/or complement experimental researches. As a result, the main objective of this study was to establish a 3D RANS model (i.e., reasonable computational cost and running time) that can provide in-cylinder details and predict the efficiency of a 6V150 diesel engine under varied operating conditions. A sector mesh approach was employed, considering only the compression, combustion, and expansion periods from intake valve closing to exhaust valve opening. The results indicated that the model simulated cylinder pressure agreed well with the experimental data, with relative errors of less than 6% during the primary compression, combustion, and expansion. Further, the model predicted heat release phasing was inconsistent with the experimental results, with absolute errors of less than one crank angle degree for peak pressure location, CA50, and ignition delay. In addition, the multidimensional model captured the effects of environmental pressure and temperature on spray formation (i.e., the dominant phenomenological event). Moreover, the model reasonably reproduced the effects of engine control variables on performance and emissions. All these observations demonstrated the validity of the selection and calibration of geometry, chemistry, and submodels including turbulence, spray, heat transfer, combustion, etc. Overall, the model was deemed capable of predicting combustion characteristics under extreme conditions, including high-temperature, high-cold, and high-altitude environments, which can facilitate the development of smart engines.

Investigation of the Effect of Altitude on In-Cylinder Heat Transfer in Heavy-Duty Diesel Engines Based on an Empirical Model

Abstract Diesel engines are the predominant power source for the trucking industry. Heavy-duty trucks carry more than 70% of all goods transported across the United States. Atmospheric conditions vary with altitude but are critical to diesel engine performance, efficiency, and emissions. Existing studies have reported reduced thermal efficiency and increased emissions when truck engines were operated at high altitudes. Since heat loss is a key parameter related to engine efficiency, the goal of this paper was to investigate the altitude impacts on the in-cylinder heat transfer characteristics. Experiments on a single-cylinder four-stroke heavy-duty diesel engine were conducted at a constant speed and load, but with different intake pressures to simulate the varying atmospheric conditions at different altitudes. The quantity of diesel fuel injected into the cylinder per cycle was increased to maintain the same power output at decreased atmospheric pressure and to compensate for the combustion deterioration that occurred inside the cylinder. Experimental results showed that the bulk temperature was higher at high altitudes because of less mass of the mixture trapped in the cylinder. Such a large temperature difference between the hot products and the cold walls increased the in-cylinder heat transfer to the coolant, especially during combustion. Specifically, the 2000 m altitude rise led to an increase in heat loss to the atmosphere of ∼2% per cycle under full load conditions. As a result, the application of thermal coatings to improve fuel economy is even more necessary in high altitude states, such as Colorado and Wyoming.

Improving the efficiency of diesel engines of agricultural machines

The article discusses the development process of an internal hydraulic locking system for diesel injectors, which allows to reduce fuel consumption during idling and low loads. The development of a new effect based on functional analysis and the use of the TRIZ system (Theory of Inventive Problem Solving) is shown. At the same time, the effect of resolving technical contradictions is used. The proposed design will allow to increase the range of the fuel flame without changing the performance of the high-pressure fuel pump, which will, by upgrading the nozzle needle, provide an improvement in the working process of the diesel engine when idling and at low loads. The proposed system can be used in diesel engines of agricultural machines, as well as in various types of transport.

Experimental and Analytical Study of Temperature Swing Piston Coatings in a Medium-Duty Diesel Engine

<div class="section abstract"><div class="htmlview paragraph">The use of Thermal Barrier Coatings (TBCs) has been shown to be a promising technology to improve internal combustion engine efficiencies by reducing heat rejection to the coolant and oil. In recent studies, temperature swing coatings that have simultaneously low volumetric heat capacity and low thermal conductivity have been shown to be particularly promising in this regard. In this study, a traditional and a newer swing coating are applied to the piston of an on-road medium-duty diesel engine to assess the benefits of their use. An analytical wall temperature model is coupled to the 1-D engine simulation software GT-POWER and predictions of wall temperature, heat transfer and chemical heat release rate are presented. The swing coating is found to yield an ~1.2% efficiency benefit at the highest load condition studied alongside an 80°C improvement in exhaust temperature at the lowest load condition studied compared to a reference uncoated piston. Further, the traditional TBC was not found to have a significant efficiency advantage over the reference uncoated piston, highlighting the promise of the swing coating in improving the thermal efficiency of on-road diesel engines.</div></div>

Effects of Multi-Stage Split Injection on Efficiency and Emissions of Light-Duty Diesel Engine

The efficiency of light-duty diesel engines should be improved for further emissions regulation. Multi-stage split injection with five injection events was investigated for improvement in efficiency at low-load conditions. The injection timing and quantity were adjusted to achieve a smooth in-cylinder pressure rise and continuous heat release. The multi-stage split injection was compared to injection strategies involving two-pilot and single-main injections. A 0.5 L single-cylinder diesel engine experiment was conducted under low-load conditions. Two multi-stage split injection processes with different combustion phases were developed. The multi-stage split injections yielded a smooth in-cylinder pressure trace and a lower peak heat release rate than the two-pilot injection process. The combustion duration was shorter for multi-stage split injection with an advanced combustion phase, and the fuel consumption was reduced by 1.78% with lower heat transfer, exhaust heat, and combustion loss. The multi-stage split injection flame penetration was shorter than the two-pilot injections. The shorter flame penetration and lower tip velocity reduced the heat transfer to the combustion chamber. The PM emissions were also reduced by 30% under the same NOx emissions, because increased PM oxidation and divided fuel injection prevented flame diffusion and improved air utilization.

Effects on the transient energy distribution of turbocharging mode switching for marine diesel engines

Nowadays, the high-power density and high efficiency of marine diesel engines make the requirements of high boost pressure and wide-range intake flow increased. In this study, a two-stage sequential turbocharging (TSST) system is presented as a method for increasing the power density and broadening the efficient working range of diesel engines. Through experimental and analysis methods, the relationships of intake and exhaust energy migration and exhaust energy distribution in the turbocharging mode switching process of the TSST system are investigated, and the optimal control strategy for the switching valves is obtained. The experimental results show that the optimized valve control strategy can achieve a reasonable distribution and efficient utilization of exhaust energy during the switching process. More specifically, the boost pressure error function is only 0.0003 kPa2·s, the engine speed fluctuation amplitude is less than 6 r/min, and the speed transition time is less than 8 s. A smooth switching between the turbocharging modes of the TSST system is achieved, exhaust energy loss is minimized, and the fuel economy and power performance of marine diesel engines over the entire range of operating conditions are effectively improved.

Numerical Investigation of the Application of Miller Cycle and Low-Carbon Fuels to Increase Diesel Engine Efficiency and Reduce Emissions

In this paper, validated simulations using Ricardo WAVE have been performed to investigate the effect of the Miller cycle and low-carbon fuels on the performance (power, torque, BTE and BSFC) and emissions of a diesel engine. The results show that the increased Miller cycle effect (larger deviation of the advanced or retarded intake valve closing from the standard intake valve closing time) will decrease NOx, CO and HC emissions, and slightly improve brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) with slight loss in engine performance and increase in soot emissions. An engine running B0 (diesel with 0% Biodiesel in the blend) with a −18% Miller cycle effect has a reduction in NOx of 9% and CO of 4.3% with a decrease of 1.6% in power at the rated engine speed. Using low carbon fuels drastically reduces emissions with reduced BTE and increased BSFC. When used in conjunction, the Miller cycle and low-carbon fuels have an improved effect on both performance and emissions. The optimal results demonstrate that using B60 (60% Biodiesel in the blend) and a −8% Miller effect contributes to a 1.5% improvement in power, 1.2% in BTE, 13.3% in NOx, 38.5% in CO, 8.9% in HC, and 33.0% in soot at a cost of 6.0% increase in BSFC. The results show that it is an easy way to reduce NOx, CO, HC and soot emissions and increase the BTE of the engine by combining Miller cycle and low-carbon fuels.

Transitioning to sustainable freight transportation by integrating fleet replacement and charging infrastructure decisions

The transportation sector is the largest contributor to global greenhouse gas emissions. Disruptive technological changes in this sector, such as alternative fuel vehicles, are crucial for emission reduction. We show how a cost-minimizing strategic transition plan to adopt electric trucks over time can be developed for a firm that owns and operates a fleet of diesel trucks. We consider the case in which the firm decides to invest in the charging infrastructure required to support this transition, either because the public charging infrastructure is currently inadequate or for strategic reasons. The congestion effect at the charging stations, the charging times, and the potential loss of productive driving time due to detours to reach charging stations are explicitly considered. By developing an independence property, we are able to model this problem as a linear integer program without specifying origins and destinations. We illustrate the resulting transition plan with realistic parameter configurations. Our results indicate that a firm with high transportation demand density over a given service region significantly benefits from adoption of electric trucks, while also enjoying substantial carbon emissions savings. High demand density also favors smaller battery capacity with shorter ranges under the optimized charging network capacity, even though larger battery capacity would increase productivity with extended ranges. Our analysis also offers insights for governments and regulators regarding the impact of several influential factors such as carbon cost, content of renewable energy in electricity mix, diesel engine efficiency, and subsidizing the charging infrastructure. Additionally, we present an extension to the model that allows for different modalities of partnership in the infrastructure investment; notably public-private and private-private partnerships. While in general our results suggest that such partnerships are beneficial to all involved, the amount and relative distribution of the potential gains depend on the topography and on the density of charging infrastructure.

A literature survey on exergy analyses of marine diesel engine and power systems

The oil crisis in the world has led countries to seek an alternative fuel that can replace fossil fuels. In addition, the fact that global warming, which is one of the most important problems for the world, has reached significant levels, has led to an increase in studies on greenhouse gas emissions and the efficient use of energy. Every effort to increase efficiency contributes to both environmental and economic improvements. Considering this situation, the study was compiled by examining the studies on energy and exergy analysis related to diesel engines and marine diesel power systems in the literature. As a result of the study, it has been seen that the use of different fuel types contributes significantly to the decrease in environmental emissions as well as the increase in efficiency in diesel engines. In addition, it is thought that there are few studies in the literature on ship diesel engines, and with the increase in the studies to be done on this subject, there may be important references to both companies engaged in maritime transport and studies that will conduct research on this subject.