Fuel Efficiency Research Articles

Unhiding the role of CHP in power & heat sector decomposition analyses

In many countries the role of combined heat & power (CHP) generation in the power & heat sector is significant. However, in decomposition analyses of the power & heat sector the contribution of CHP to observed changes in primary energy use or CO2 emissions is generally not made explicit. In this paper, the contribution of CHP is shown for eight countries (China, Denmark, France, Germany, Italy, the Netherlands, Poland and the USA) in the period 2005–2016. In addition, an alternative method is proposed for power & heat sector decomposition analysis with five driving factors: volume effect, subsector effect, heat effect, fuel mix effect and efficiency effect. This method combines indicators from existing decomposition methods and complements them with a CHP specific heat effect. The proposed method provides improved insight in the factors driving change in primary energy use or CO2 emissions in the power and heat sector, especially in case changes take place regarding either 1) the power-to-heat ratio, 2) the share of CHP electricity in total electricity production, 3) the CHP fuel mix, and/or 4) the efficiency of individual CHP fuels.

Kalman Filter-Based Real-Time Implementable Optimization of the Fuel Efficiency of Solid Oxide Fuel Cells

The electric power characteristic of solid oxide fuel cells (SOFCs) depends on numerous influencing factors. These are the mass flow of supplied hydrogen, the temperature distribution in the interior of the fuel cell stack, the temperatures of the supplied reaction media at the anode and cathode, and—most importantly—the electric current. Describing all of these dependencies by means of analytic system models is almost impossible. Therefore, it is reasonable to identify these dependencies by means of stochastic filter techniques. One possible option is the use of Kalman filters to find locally valid approximations of the power characteristics. These can then be employed for numerous online purposes of dynamically operated fuel cells such as maximum power point tracking or the maximization of the fuel efficiency. In the latter case, it has to be ensured that the fuel cell operation is restricted to the regime of Ohmic polarization. This aspect is crucial to avoid fuel starvation phenomena which may not only lead to an inefficient system operation but also to accelerated degradation. In this paper, a Kalman filter-based, real-time implementable optimization of the fuel efficiency is proposed for SOFCs which accounts for the aforementioned feasibility constraints. Essentially, the proposed strategy consists of two phases. First, the parameters of an approximation of the electric power characteristic are estimated. The measurable arguments of this function are the hydrogen mass flow and the electric stack current. In a second stage, these inputs are optimized so that a desired stack power is attained in an optimal way. Simulation results are presented which show the robustness of the proposed technique against inaccuracies in the a-priori knowledge about the power characteristics. For a numerical validation, three different models of the electric power characteristic are considered: (i) a static neural network input/output model, (ii) a first-order dynamic system representation and (iii) the combination of a static neural network model with a low-order fractional differential equation model representing transient phases during changes between different electric operating points.

Influence of Short Carbon-Chain Alcohol (Ethanol and 1-Propanol)/Diesel Fuel Blends over Diesel Engine Emissions

Oxygenated fuels, in this case short carbon-chain alcohols, have been investigated as alternative fuels to power compression ignition engines. A major advantage of short-chain alcohols is that they can be produced from renewable resources, i.e., cultivated commodities or biomass-based biorefineries. However, before entering the market, the effects of short-chain alcohols on engine performance, exhaust emissions, noise and sound quality need to be understood. This work sheds light on the relationship between the physicochemical properties of the alcohol/diesel fuel blends (ethanol and 1-propanol) on engine performance, exhaust emissions and, for the first time, on noise and sound quality. It has been demonstrated that when the content of alcohol in blends increased, soot and soluble organic material emissions drastically decreased, mainly due to the increase of oxygen content in the fuel. Reduction in soot emissions combined with higher thermodynamic efficiency of alcohol fuels, with respect to diesel fuel, enable their utilization on compression ignition engines. There is also an improvement in the soot-NOx trade off, leading to large reductions on soot with a small effect on NOx emissions. The oxygen content within the fuel reduces CO and THC emissions at extra-urban driving operation conditions. However, hydrocarbons and CO emissions increased at urban driving conditions, due to the high heat of vaporization of the alcohol fuels which reduces cylinder temperature worsening fuel atomization, vaporization and mixing with air being more significant at lower cylinder temperature conditions (low engine loads and speeds). Similarly, the higher the presence of alcohol in the blend, the higher the noise emitted by the engine due to their low tendency to auto-ignition. The optimization of alcohol quantity and the calibration of engine control parameters (e.g., injection settings) which is out of the scope of this work, will be required to overcome noise emission penalty. Furthermore, under similar alcohol content in the blend (10% v/v), the use of propanol is preferred over ethanol, as it exhibits lower exhaust emissions and better sound quality than ethanol.

Extrusion as a novel production method for MOX (UO2-PuO2) fuel rods: Rheological and physical characterizations on surrogate pastes

To improve the manufacturing efficiency of ceramic MOX fuels, wet processes, such as extrusion, are studied as a novel production method. The flowing behavior, is essential to obtain smooth and defectless rods. This work provides a study on the rheological properties of the paste and assesses the possibility to produce MOX nuclear fuel by extrusion.Surrogate ceramic powders of UO2 and PuO2 were used, respectively TiO2 and Y2O3. A paste with 40.9%vol ceramic loading, yielded smooth, defect free and dense rods. The paste rheology was studied with a ram extruder, using the Benbow-Bridgwater empirical model for ceramic extrusion, and capillary rheometry. The extrusion pressure was predicted using a combination of Benbow-Bridgwater’s approach including a Herschel-Bulkley modeling for the extensional flow at the entry die, and for the viscoplastic flow behavior in the die. The fired extrudates had a homogeneous microstructure and achieved a 95.0 ± 0.9% density with few micropores.

Fuel burning efficiency under various fire severities of a boreal forest landscape in north-east China

Forest fires are important natural disturbances that influence accurate estimations of forest carbon budgets, largely owing to the uncertainty of carbon emissions from forest fires. Fuel burning efficiency is an important factor affecting accurate estimations of carbon emissions and is difficult to quantify. Here, we quantified burning efficiencies of fuel strata by fire severity and forest types and investigated influencing factors. Burning efficiencies of fuel strata increased with increasing fire severity. The tree stratum had low values of burning efficiency of 0.76, 0.83, 6.84% under low-, moderate-, high-severity fires respectively. The burning efficiency of the herb stratum was the highest, over 95%, followed by the litter stratum between 49 and 85%. Although the tree stratum accounted for the largest carbon storage of aboveground fuels, most carbon consumed during fires came from the shrub and herb strata. Among forest types, the burning efficiency of aboveground fuels in Pinus pumila–Larix gmelinii forest was much higher than the other two studied. Fire Weather Index (FWI) and temperature exerted a positive effect on the burning efficiency of understorey fuels. Precipitation mainly had a negative influence on the burning efficiency of shrub and duff.

Modifying Single-Cylinder Diesel Engine Become Dual-fuel System to Reduce NOx Emission and Maintain Fuel Efficiency

Tier III of Annex VI from MARPOL 73/78 about NOx emission control soon may be implemented at a global level. There are three potential methods to fulfill the Tier III. First is derating power, second is using gas as fuel, and the third one is installing SCR. This research deals with using CNG as diesel engine fuel. This initial study was occupied a single-cylinder diesel engine. Gas cannot burn inside conventional diesel cycles. Dual fuel technology also tends to reduce fuel efficiency compared with the conventional one. Therefore, the single-cylinder engine was modified its piston crown part to overcome both problems. The modification of piston crown geometry affects the engine compression ratio. Modify the conventional diesel engine to become the dual-fuel type is concluded as a potential technique to be developed. The study results show NOx reduction up to 33.68% and the fuel efficiency increase up to 1.512% without any disruption to the engine operating conditions.

Оценка воспламеняемости топлив для судовых дизельных двигателей

There were studied the influence of composition of foreign marine fuels on its quality indexes which estimate the combustibility and combustion efficiency of this fuels in the marine reciprocators. It was found that using the high-density fuels in the engines of marine technique, which specified for exploitation on the automotive diesel fuels, can be the cause of decreasing the combustion efficiency, increasing of smokiness of exhaust gases and facility of technique’s failure. Using of methyl esters of fatty acids in the marine fuel’s composition in concentrations until 1 mass percent influents positively on combustibility and combustion efficiency. This result in the aggregate of results of other researches of influence these concentrations of FAME on the emulsification and lubricity of marine fuels follows to possibility of its short-time using marine technique. Experimentally proved the necessity of offered calculating method which estimates the combustion efficiency and combustibility of marine fuels. It was found that this method is more adequate and sensitive for estimation of those properties of heavy marine diesel fuels and petroleum diesel fuels with the FAME contention then the method of estimation of Cetane Index (GOST 27768).

Оценка точности измерения параметров автомобиля на стенде с беговыми барабанами

Fuel efficiency is one of the indicators for evaluating the efficiency of rolling stock. The article discusses the main reasons that determine the need to assess the fuel efficiency of road vehicles during their operation. An analysis of recommendations for the accuracy of measuring vehicle parameters in regulatory documents was given. The goal of the work was formulated, which is to develop measures to improve the accuracy of measurements during bench tests of cars. The main features of measuring fuel consumption on a simulation stand with running drums were considered. Formulas for calculating fuel travel on the road and on the stand with running drums were presented. A criterion for the similarity of road and bench tests for the fuel efficiency of a car was determined. The factors that influence the measurement of fuel consumption were considered. The general measuring scheme of the simulation bench was drawn up. The components of the load-speed modes for the stand operation were analyzed. A metrological assessment was made of the equipment used to measure the torque and rotation speed of the drive shaft of the running drums. A diagram of the calibration process of a strain gauge beam was given, which is used to measure the torque on the running drums of the stand and the wheels of a car. An assessment was made of the regularity of the change in the output channel of the measuring signal from the torque. The characteristic of the relative error was obtained for two ranges of load measurements. The influence of the frequency and number of successive measurements on the convergence of the accuracy of determining the fuel consumption, speed and load of the vehicle during bench tests was established. The optimal measurement time was obtained with an acceptable accuracy. The general dependence of the total error in measuring fuel consumption on a stand with running drums was obtained, taking into account the accuracy of measuring, processing and sampling the signal. The influence of the sampling frequency of the analog-to-digital conversion on the measurement accuracy was assessed. Conclusions and recommendations were developed, which indicated the main avenues for further research.

Temperature inversion of the action of multilayer fullerenoid structures in the oxidation of N-decan by molecular oxygen

It was established that at low temperatures MFS inhibit the oxidation of n-decan, and at temperatures close to the boiling point of the hydrocarbon, on the contrary, accelerate the transformation of the original alkane molecules. The composition of alkane transformation products in the high-temperature two-phase (gas-liquid) oxidation regime was analyzed by gas-liquid chromatography. It is shown that the transformation of n-decan molecules occurs according to the same schemes both in the case of oxidation without the additive of MFS, and in the presence of these compounds in a liquid. The work is devoted to the actual problem of increasing the energy efficiency of liquid motor fuels (gasoline, diesel and jet fuels) in transport power plants. One of the most acceptable ways to solve this problem at the present stage, which does not require capital expenditure, is to improve the processes of chemical transformations of fuel molecules in engines under the action of additives. The use of multilayer fullerene-like structures (MFS) as additives to motor fuels is proposed. The influence of additives modified MFS on the conversion of reagents in the processes of liquid-phase oxidation of n-decan by molecular oxygen at low (70°C) and high (150°C) temperatures has been studied. The change in the direction of the MFS action on chemical transformation of initial reagents depending on process temperature is experimentally revealed. It was established that at low temperatures MFS inhibit the oxidation of n-decan, and at temperatures close to the boiling point of hydrocarbons, on the contrary, accelerate the transformation of the original alkane molecules. The composition of alkane transformation products at high-temperature two-phase (gas-liquid) oxidation regime was analyzed by gas-liquid chromatography. It is shown that the transformation of n-decan molecules occurs according to the same schemes both in the case of oxidation without the additive of MFS, and in the presence of these compounds in a liquid.

Socio-Economic Rebound Mechanisms in Automobile Fuel Efficiency in the European Union: A System Dynamics Model

Socio-Economic Rebound Mechanisms in Automobile Fuel Efficiency in the European Union: A System Dynamics Model

Eco-Driving and Its Impacts on Fuel Efficiency: An Overview of Technologies and Data-Driven Methods

Eco-driving is a multidimensional concept that includes driving behavior, route selection and all other choices or behaviors related to the vehicles’ fuel consumption (e.g., the use of quality fuel, the use of air conditioning, driving at peak hours, etc.). The scope of this paper is to present an overview of recent literature referring to eco-driving and developed models for calculating fuel consumption, as well as the most important factors affecting it. Recent literature contains a large number of models that estimate fuel consumption, based on naturalistic driving data, which are collected using smartphones and OBDs. In this work, the existing literature is critically assessed in relation to conceptual, methodological and data related aspects. The analyses result to a set of limitations and challenges that are further discussed in the framework of system wide implementations for deriving policies that increase drivers’ awareness, but also improve system performance.

Local organization for promoting energy efficiency\u2014reform of local energy advice service in Sweden

Homeowners are identified as a group in society that could change their energy behaviour towards greater energy efficiency and use of non-fossil fuels. External local energy advisors, who provide knowledge, motivation and service, can influence their decisions and thereby increase energy efficiency and dissemination of non-fossil fuels. In Sweden, the energy advice system has recently been reformed and this paper investigates this reform and analyses its early effects. The aim is to analyse how energy advisors manage the reform and how they work as middle actors to increase energy efficiency and non-fossil fuel use among homeowners. We use the theoretical framework of middle actors in the middle-out perspective together with the theory of institutional logics to analyse the case of the energy advisor reform. This qualitative analysis contributes to the discussion of energy advisors by focusing on the relevance of organizational structures and logics for their possibilities to influence homeowners’ energy practices. The reform has introduced a governance and New Public Management logic that runs parallel with the former energy advice logic, guiding the advisors’ work practice. The results show that the reform potentially has increased the energy advisors’ ability to act as middle actors. However, there are organizational practices following the reform, which greatly constrain the advisors’ abilities as middle actors. One conclusion is that the advisors are in need of more guidance from the Energy Agency to be able to perform more successful work.

An assessment of emission characteristics of Northern Hemisphere cities using spaceborne observations of CO2, CO, and NO2

Intensified anthropogenic activities and high levels of energy consumption in cities have led to an increase in emissions of CO2 and air pollutants, impacting air quality and calling for better measures to monitor and reduce emissions. This study assesses the emission characteristics of cities in the Northern Hemisphere during two winter seasons from December 2018 to March 2020 using a combination of CO2 observations from the Orbiting Carbon Observatory-2 (OCO-2) along with CO and NO2 observations from the Sentinel-5 Precursor TROPOspheric Monitoring Instrument (S-5P TROPOMI). We calculate the estimates of urban enhancement concentrations of CO2, CO, and NO2 from anthropogenic emissions in cities. Moreover, using ratios of CO/CO2 and NO2/CO2 according to each city, we analyze the relationship between CO2 and air pollutants and find that cities show distinct emission patterns according to where they are located in different regions of the world. Our analysis shows that a positive relationship exists in the comparisons of CO/CO2 and NO2/CO2 ratios to city population and GDP. However, when cities in the Northern Hemisphere are divided into “developed” and “developing” regions, a difference in pattern is found where most developed cities show a smaller increase of both CO/CO2 and NO2/CO2 ratios with the increase of GDP, while developing cities show a larger increase of ratios per increase of GDP. Especially, developing cities facing rapid economic development like Mumbai and Tianjin show high emission ratios that almost match that of developed cities. The higher incline of increase in emission ratios in developing cities can be attributed to the low combustion efficiency of fossil fuels along with less stringent pollution control measures. This implies that pollution control measures are crucial for effective management of air quality degradation with economic advancement within these developing cities. The analysis also highlights the importance of urban geological features in cities such as that of Tehran and Milan which can trap air pollution under appropriate meteorological conditions. Despite the short period of analysis, our study demonstrates that satellite observations of CO2 and air pollutants together can provide clues about factors controlling the co-emission of air pollutants and carbon in cities and suggests that the application of the proposed methods with longer periods of observation will support coupled air quality and climate mitigation strategies.

WITHDRAWN: Reduction of drag in box-type and half streamlined automobile vehicles

Fuel efficiency, mileage, cost and comfortable of the car is the key factors for customer attraction, apart from above features; fuel efficiency plays a major role for the overall attractiveness of car. An Influencing factors for fuel efficiency of cars are based on the performance of internal combustion engines and also on the aerodynamic design of body of the car. In the total, 50% of fuel consumption is obtained by the aerodynamic drag force at highway speeds. The drag force is formed by relative motion between air and vehicle. The objective of this project is to trim down the drag coefficient in sedan and SUV cars by reducing the turbulence at exit of the car and reducing the skin friction drag. In SUV car model, tapered smooth edges are used for the analysis, in sedan car, diffuser is used for the analysis purpose. While designing an automotive, the aerodynamic drag plays a major role. Due to the aerodynamic design, the entire performance of the automotive will be changed. In recent years, the demand for the fuel has been increasing, so extensive research is undergoing for improvement of aerodynamically optimized vehicle designs by using PTC Creo Parametric software and Autodesk Flow Design software. The simulation results are taken under the concept of Computational Fluid Dynamics with necessary boundary conditions.

Fuel Efficiency and Engine Power in Hybrid and Electric Vehicles - A Review Study

Fuel Efficiency and Engine Power in Hybrid and Electric Vehicles - A Review Study

Исследование влияния магнитной обработки топлива на работу судового двигателя

The article considers the influence of the fuel magnetic treatment onto the operation of a ship engine. Many shipowners are interested in reducing their fuel consumption. Fuel efficiency is one of the most important indicators of a ship's engine. There are various methods to improve the fuel quality. In addition to traditional physical and chemical methods, wave effects are also used, for example, a magnetic treatment. The magnetic treatment effectiveness for diesel fuels has been confirmed by many studies. The analysis of the influence of the magnetic treatment of diesel fuel with a magnetic induction of 0.4 T on the operation of a 4CHN9.5/11 marine engine under different modes is carried out. Magnetic treatment of the fuel was carried out by creating a magnetic field with permanent magnets NdFeb (neodymium - iron - boron) installed in special magnetizers on the fuel line to the high-pressure fuel pump.The methods of analysis of changes in external indicators of the 4CHN9.5/11 engine during magnetic treatment of fuel are considered. The pictures of the 4CHN9.5/11 engine tested are presented. The results of the parameters of the 4CHN9.5/11 diesel engine (effective power, speed, average effective pressure, hourly fuel consumption, specific effective fuel consumption) during tests on load and screw characteristics before or after installation of the magnetizer are presented. The bench tests have confirmed that the reduction in fuel consumption when testing a diesel engine running on magnetically treated fuel makes 5-8%. It is noted that with other types of marine fuel and on other models of engines it is possible to clarify the methods of using magnetic processing in sea and river transport

A Conjoint Based Approach on Female Customers’ High Relevant Attributes Towards Passenger Car Preferences

Automobile industry has become more competitive in recent years as customers’ expectations are ever changing. As the nature of the environment grows more competitive, the demand to meet customer expectations has grown significantly. One of the key pieces of information that would assist car manufacturers is an underlying of what determines customer preferences. The research focused on (1) exploring the attributes most-preferred by female customers when selecting a car to buy; (2) to evaluate the relative importance of the various levels of each attribute that influence the selection of a car by female customers and (3) to identify relative priority of attributes across different groups of female customers. The current research design employed qualitative as well as quantitative methods. To generate attributes Thematic analysis was employed that were then used to construct a questionnaire for quantitative survey. In the quantitative section both conjoint and cluster analysis was involved in the decision to select cars through which a final sample size of 435 responses obtained. Using conjoint analysis, to investigate the importance of car attributes in Chennai. The result indicates that the six most important attributes female customer prefer were Gear type, Body type, Safety, Price, Color and Fuel efficiency. Based on these findings car manufacturers can develop marketing strategies and better position their vehicles.

Fuel efficiency and exhaust characteristics of turbocharged diesel engine equipped with an electric supercharger

The electric supercharger, which is an important device of the 48 V hybrid system, is known to increase the low-speed efficiency and torque of the internal combustion engine. However, there is a lack of research on exhaust emissions, which are becoming more stringent owing to the use of the electric supercharger. Therefore, this study conducted basic experiments and analysis on the power, fuel efficiency, and exhaust emissions according to the change of engine control parameters during operation of the electric supercharger. The maximum indicated mean effective pressure (IMEP) increase was 52.9% at 1250 rpm. However, friction mean effective pressure (FMEP) and pumping mean effective pressure (PMEP), associated with a loss of engine efficiency, increased under various operating conditions. Brake specific fuel consumption (BSFC) improved by up to 8.8%, and brake specific carbon dioxide (BSCO2) decreased accordingly. Brake specific particulate matter (BSPM) and brake specific oxides of nitrogen (BSNOx) fluctuated significantly with the adjustment of the parameters for engine control. These were partially reduced compared to the conventional engines according to the experimental conditions. Therefore, even if an electric supercharger is applied to a diesel vehicle equipped with exhaust reduction devices, emission regulations can be satisfied.

Where does all the biofuel go? Fuel efficiency gains and its effects on global agricultural production

Increasing biofuel production over the last decade and biofuel policies in Brazil, the European Union, and the United States have changed the global agricultural landscape in terms of land-use, commodity prices, and trade. Increasing fuel efficiency and electrification of the vehicle stock is projected to lower gasoline, diesel, and biofuel demand in the future. In this analysis, we quantify the effects of a 30% reduction in ethanol consumption in the U.S. and the European Union triggered by higher vehicle fleet fuel efficiency on global agricultural markets. Our results show decreases in global commodity prices by 1.9%–6.6% and a slight decrease in global cropland by 0.3%. Major changes occur in trade patterns with U.S. corn exports increasing by 30.3%. Global greenhouse gas emissions are lower due to the overall reduction in cropland. Gasoline and diesel consumption of the vehicle fleet is not changing rapidly but is a long-term process because vehicles are on average in operation for 10 or more years. Consequently, there are important long-term policy implications from changes in fuel efficiency requirements or ethanol blending limits that affect commodity prices, trade, and greenhouse gas emissions.

Research on a Method of Evaluating Fuel Efficiency during Traveling and Driving for Head-feeding Combine Harvesters

Research on a Method of Evaluating Fuel Efficiency during Traveling and Driving for Head-feeding Combine Harvesters