Fuel Consumption Characteristics Research Articles

Operating Point Optimization of Auxiliary Power Unit Based on Dynamic Combined Cost Map and Particle Swarm Optimization

Series hybrid electric vehicles improvements in fuel consumption and emissions directly depend on the operating point of the auxiliary power unit (APU). A new APU operating point optimization approach based on dynamic combined cost map (DCM) and particle swarm optimization (PSO) is presented in this paper. The influence of coolant temperature, catalyst temperature, and air/fuel (A/F) ratio on fuel consumption characteristics and HC, CO, NOx emission characteristics are quantitatively analyzed first. Then, the DCM is derived by combining the individual cost maps with predefined weighting factors, so as to balance the potentially conflicting goals of fuel consumption and emissions reduction in the choice of operating point. The PSO is utilized to search the optimum APU operating point in the DCM. Finally, bench experiments under three typical driving cycles show that, compared with the results of the traditional static steady-state fuel consumption map-based APU operating point optimization approach, the proposed DCM and PSO-based approach shows significant improvements in emission performance, at the expense of a slight drop in fuel efficiency.

Emissions and fuel consumption characteristics of a heavy duty diesel engine fueled with Hydroprocessed Renewable Diesel and Biodiesel

Renewable biofuels such as Hydroprocessed Renewable Diesel (HRD) and Biodiesel (B100) are perceived as potential alternative fuels for compression ignition (CI) engine. HRD and B100 are produced from the same feedstock i.e. Jatrophacurcas oil by transesterification and hydro-deoxygenation reactions respectively. Petro-diesel served as a reference fuel. The main objective of this study is to identify a better alternative fuel among HRD and B100 in terms of emissions and fuel consumption characteristics. The C–H–O based lubricity additive was added in HRD to give adequate lubricity to fuel injection pump. Both biofuels showed substantial reduction in particulate matter (PM), carbon monoxide (CO) and hydrocarbon (HC) emissions as compared to petro-diesel. But NOx increased by 26% for HRD and 77% in the case of B100 fueled engine. Brake specific fuel consumption (BSFC) of the engine fueled with HRD was lower than with B100 and petro-diesel. A comparative analysis of emission results revealed that the engine fueled with B100 performed well on many counts such as PM, CO and HC, but the HRD outperformed B100 in terms of NOx emission and BSFC, which are vital parameters for CI engines. Hence, HRD may be considered as a promising alternative fuel for CI engines over other transesterified biodiesels.

Spatio-temporal analysis of car distance, greenhouse gases and the effect of built environment: A latent class regression analysis

This work examines the temporal–spatial variations of daily automobile distance traveled and greenhouse gas emissions (GHGs) and their association with built environment attributes and household socio-demographics. A GHGs household inventory is determined using link-level average speeds for a large and representative sample of households in three origin–destination surveys (1998, 2003 and 2008) in Montreal, Canada. For the emission inventories, different sources of data are combined including link-level average speeds in the network, vehicle occupancy levels and fuel consumption characteristics of the vehicle fleet. Urban form indicators over time such as population density, land use mix and transit accessibility are generated for each household in each of the three waves. A latent class (LC) regression modeling framework is then implemented to investigate the association of built environment and socio-demographics with GHGs and automobile distance traveled. Among other results, it is found that population density, transit accessibility and land-use mix have small but statistically significant negative impact on GHGs and car usage. Despite that this is in accordance with past studies, the estimated elasticities are greater than those reported in the literature for North American cities. Moreover, different household subpopulations are identified in which the effect of built environment varies significantly. Also, a reduction of the average GHGs at the household level is observed over time. According to our estimates, households produced 15% and 10% more GHGs in 1998 and 2003 respectively, compared to 2008. This reduction can be associated to the improvement of the fuel economy of vehicle fleet and the decrease of motor-vehicle usage – e.g., a decrease of 4% is observed for fuel efficiency rates and 12% for distance according to the raw average estimates from 1998 with respect to 2008. A strong link is also observed between socio-demographics and the two travel outcomes. While number of workers is positively associated with car distance and GHGs, low and medium income households pollute less than high-income households.

On modeling microscopic vehicle fuel consumption using radial basis function neural network

Energy conservation is one of the central challenges for the transportation system today. A variety of microscopic vehicle fuel consumption models have been developed to support eco-friendly transport strategies. However, most existing models are regression based and are sensitive to the vehicle-specific parameters and the operating conditions, therefore, an expensive and time-consuming calibration procedure is always indispensable in these models' application. In this paper, we propose an artificial neural network-based model to avoid the calibration problem. The main works include: (1) collect extensive field datasets such as large-scale controller area network bus to reflect the local transportation environment's fuel consumption characteristics; (2) conduct correlational analysis to identify the key fuel consumption influence factors; (3) develop a radial basis function neural network-based learning model to capture the nonlinear relationship between the key factors and the corresponding fuel consumption values based on the collected training datasets. The proposed model can give a reasonable prediction of instantaneous fuel consumption without calibration. The effectiveness of the proposed model is validated from a combination of both in-lab and field experiments.

Comparison of Test Standards for the Performance and Safety of Agricultural Tractors: A Review

Purpose: The objective of this paper was to compare test standards regarding the performance and safety of agricultural tractors to identify the differences in test conditions, measurement tolerances, and test procedures. Based on the comparison, some recommendations were proposed for possible rev isions or improvements to current tractor test standards. Methods: The test standards and codes of major standards development organizations (SDOs), such as the Organization for Economic Co-operation and Development (OECD), the International Organization for Standardization (ISO), the American Society of Agricultural and Biological Engineers (ASABE), EC type approval, and the board of actions of the Nebraska Tractor Test Laboratories (NTTL), were selected and analyzed. Comparison of the test standards: The ISO provides references for fuel and lubricants for tractor tests, and the OECD provides additional measurements for calculating fuel consumption characteristics during the power take-off (PTO) tests. The ISO, EC type approval, and the ASABE provide PTO protective device and the safety requirements. During drawbar power tests, seven transmission ratios are selected for fully automatic transmissions, according to the OECD. In case of hydraulic lift tests, ISO 789-2 and OECD Code 2 advise the use of a static lift force, while SAE J283 advises the use of additional dynamic lift capacity tests for a better representation of in-field operations. The OECD, the ISO, and EC type approval determine the seat index point (SIP), whereas the ASABE determines the seat reference point (SRP) for roll-over protective structure (ROPS) tests. Diversified measurement tolerances were among the braking performance test standards. The European Union (EU) has developed daily limits for vibration exposures with adaptations from ISO 2631-1. Electroma gnetic compatibility evaluations are emerging of high-efficiency tractors due to the long-term conformance to electromagnetic emissions and interferences. Comparisons of tractor test standards discussed in this paper are expected to provide useful information for tractor manufacturers and standards development personnel to improve the performance and safety test standards of tractors.

Emissions and fuel consumption characteristics of an HCNG-fueled heavy-duty engine at idle

The idle performance of an 11-L, 6-cylinder engine equipped with a turbocharger and an intercooler was investigated for both compressed natural gas (CNG) and hydrogen-blended CNG (HCNG) fuels. HCNG, composed of 70% CNG and 30% hydrogen in volume, was used not only because it ensured a sufficient travel distance for each fueling, but also because it was the optimal blending rate to satisfy EURO-6 emission regulation according to the authors' previous studies. The engine test results demonstrate that the use of HCNG enhanced idle combustion stability and extended the lean operational limit from excess air ratio (λ) = 1.5 (CNG) to 1.6. A decrease of more than 25% in the fuel consumption rate was achieved in HCNG idle operations compared to CNG. Total hydrocarbon and carbon monoxide emissions decreased when fueled with HCNG at idle because of the low carbon content and enhanced combustion characteristics. In particular, despite hydrogen enrichment, less nitrogen oxides (NOx) were emitted with HCNG operations because the amount of fuel supplied for a stable idle was lower than with CNG operations, which eventually induced lower peak in-cylinder combustion temperature. This low HCNG fuel quantity in idle condition also induced a continuous decrease in NOx emissions with an increase in λ. The idle engine test results also indicate that cold-start performance can deteriorate owing to low exhaust gas temperature, when fueled with HCNG. Therefore, potential solutions were discussed, including combustion strategies such as retardation of spark ignition timing combined with leaner air/fuel ratios.

Modelling the Hungarian energy system – The first step towards sustainable energy planning

In Hungary, there is a need for detailed alternatives to its fossil-based, highly import-dependent energy system. In this paper, an energy model of the Hungarian energy system of 2009 is worked out, as a reference model for a 100% renewable-based scenario. The model is created in the EnergyPLAN software and is able to simulate all sectors of the national energy system on an hourly basis. The EnergyPLAN software and the main issues of its first Hungarian application are presented. The model is validated by comparing its results to Hungarian and international statistics for 2009. Two alternative models – ‘Natural gas + biomass’ and ‘Biomass’ – were created in EnergyPLAN for an analysis to see how the energy system of 2009 could have been operated in an optimised way from environmental point of view, within the existing infrastructure. In ‘Biomass’ alternative model, the utilisation of primary renewable energy sources almost doubles, causing a decrease of 10% in carbon-dioxide emission. By changing the distribution of fuels by a different power plant utilisation, more favourable fuel consumption characteristics could have been achieved from the environmental point of view in 2009.

Stability enhancement of ozone-assisted laminar premixed Bunsen flames in nitrogen co-flow

Ozone (O3) is known as one of the strongest oxidizers and therefore is widely used in many applications. Typically in the combustion field, a combination of non-thermal plasma and combustion systems have been studied focusing on the effects of ozone on flame propagation speeds and ignition characteristics. Here, we experimentally investigated the effects of ozone on blowoff of premixed methane/air and propane/air flames over a full range of equivalence ratios at room temperature and atmospheric pressure by using a co-flow burner and a dielectric barrier discharge. The results with ozone showed that a nozzle exit jet velocity at the moment of flame blowoff (blowoff velocity) significantly increased, and flammability limits for both fuel-lean and rich mixtures were also extended. Ozone had stronger effects of percent enhancement in the blowoff velocity for off-stoichiometric mixtures, while minimum enhancements could be observed around stoichiometric conditions for both fuels showing linear positive dependence on a tested range of ozone concentration up to 3810ppm. Through chemical kinetic simulations, the experimentally observed trends of the enhancement in blowoff velocity were identified as a result of the modification of the laminar burning velocity. Two ozone decomposition pathways of O3+N2→O+O2+N2 and O3+H→O2+OH were identified as the most controlling steps. These reactions, coupled with fuel consumption characteristics of each fuel determined the degree of promotion in laminar burning velocities, supporting experimental observations on blowoff velocities with ozone addition.

Thermochemical conversion of fuels into hydrogen-containing gas using recuperative heat of internal combustion engines

The problem of the thermochemical recuperation of heat from the exhaust gases of internal com� bustion engines (ICEs) as a method of increasing of the efficiency of fuels has been considered. The thermo� dynamic analysis of thermochemical recuperation conditions was performed, and maximum efficiency con� ditions were determined. Catalysts for the steam conversion of oxygencontaining fuels into syngas were developed, and the Co-Mn/Al2O3 catalyst was shown to be the most promising. The model of a thermo� chemical heat recuperation system was developed and manufactured, and its bench tests in the conversion of alcohols were performed using the simulated exhaust gases from a heating device. Mathematical models for calculating units of the heat recuperation system were developed. A recuperation system was manufactured and tested in the ICEfree and ICEintegrated variants. Based on the test results, the equivalent fuel con� sumption characteristics of a recuperative ICE was revealed to decrease by 11-22% depending on its load with a decrease in the concentration of hazardous emissions by 8-12 times for CO, 2-3.5 times for CH, and 18-25 times for NO x .

Reducing greenhouse gas emissions of a heterogeneous vehicle fleet

Recent research on the vehicle routing problem attempts to integrate so-called “green” aspects into classical planning models. The minimization of transport-related emissions (especially CO2) instead of driving distances is an important integration approach. Within this paper, we propose an approach which is focusing on the reduction of CO2 emissions caused by transportation. Based on the observation that vehicles with different maximal payload values have different payload-dependent fuel consumption characteristics, we integrate into Dantzig’s classical vehicle routing model the option of choosing vehicles of different size for route fulfillment. Then, the Emission Minimization Vehicle Routing Problem with Vehicle Categories (EVRP-VC) is introduced. It aims at minimizing the fuel consumption, respectively CO2 emissions instead of the driving distances. Comprehensive computational experiments with CPLEX are conducted to evaluate the EVRP-VC. A major finding is that the quantity of fuel needed to serve a given request portfolio can be reduced tremendously by using an inhomogeneous fleet with vehicles of different size.

Spatio-Temporal Analysis of Car Distance, Greenhouse Gases and the Effect of Built Environment: A Latent Class Regression Analysis

This work examines the temporal-spatial variations of daily automobile distance traveled and greenhouse gas emissions (GHGs) and their association with built environment attributes and household socio-demographics. A GHGs household inventory is determined using link-level average speeds for a large and representative sample of households in three origin-destination surveys (1998, 2003 and 2008) in Montreal, Canada. For the emission inventories, different sources of data are combined including link-level average speeds in the network, vehicle occupancy levels and fuel consumption characteristics of the vehicle fleet. Built environment indicators over time such as population density, land use mix and transit accessibility are generated for each household in each of the three waves. A latent class (LC) regression modeling framework is then implemented to investigate the association of built environment and socio-demographics with GHGs and automobile distance traveled. Among other results, it is found that population density, transit accessibility and land-use mix have small but statistically significant negative impact on GHGs and car usage. Despite that this is in accordance with past studies, the estimated elasticities are greater than those reported in the literature for North American cities. Moreover, different household subpopulations are identified in which the effect of built environment varies significantly. Also, a reduction of the average GHGs at the household level is observed over time. According to our estimates, households produced 15% and 10% more GHGs in 1998 and 2003 respectively, compared to 2008. This reduction is associated to the improvement of the fuel economy of vehicle fleet and the decrease of motor-vehicle usage. A strong link is also observed between socio-demographics and the two travel outcomes. While number of workers is positively associated with car distance and GHGs, low and medium income households pollute less than high-income households.

Profit based unit commitment and economic dispatch of IPPs with new technique

Each generation company may have number of generating units of different fuel consumption characteristics, some generating units consume more fuel as compared to other units this directly effects the production cost and profit of the company. Production cost and profit of the company is also affected by unit commitment and economic dispatch. Each and every power generation company wants to maximize/increase profit, same is the case for independent power producers (IPPs). Profit can be maximized by changing the unit commitment and economic dispatch strategy. Previously it was achieved in such a way that production cost goes to minimum level. But as the competition in power market is going to increase day by day IPPs trend of UC solution is toward achieving maximum profit. Previously achieved solution by LR–PBUC is slow and may face convergence problem. In this paper, we will see the way how a GENCO or IPP can earn more by UC on the base of profit, with minimum computational time and always with some final solution. Hamiltonian method has been used for ED. To demonstrate the effectiveness of the PBUC achieved and Hamiltonian economic dispatch, it will be tested on two test cases. Profit and computational time comparison of proposed technique with already available/techniques for evaluation of performance are also presented.

Novel Strategies and Optimization Techniques to Reduce Harmful Diesel Engine Emissions

Abstract This article presents experimental and optimization work in developing a premixed charged compression ignition (PCCI) combustion diesel engine characterized in a low emission vehicle. An overall process to achieve PCCI combustion in a diesel engine is described, and effects of engine operating parameters such as exhaust gas recirculation rate, injection pressure, swirl ratio, and intake pressure along with injection features for fuel consumption and harmful engine-out emissions are evaluated. A late intake valve closing (LIVC) strategy was employed for further reduction in particulate matter (PM) and nitrogen oxide (NOx) emissions without sacrificing fuel economy. Design of experiments was used to evaluate the effect of three selected operating parameters and their interactions on the emission and fuel consumption characteristics of the PCCI engine. Upon optimization it was found that NOx and PM emissions could be simultaneously decreased 57% and 39%, respectively, compared to the emission level ...

Experimental Investigation to Fuel Consumption Characteristics of Light-Duty Passenger Vehicle under Sliding Condition

Technical level of driving behavior has run as high as 20% impact on vehicle’s fuel consumption, so choosing proper operation mode is one effective way to improve the vehicle’s running fuel economy. Vehicle sliding on level road is often used by driver, and analyzing vehicle’s fuel consumption characteristics during sliding condition has practical significance on realizing the reasonable driving and lowering fuel consumption. Taking some light-duty diesel passenger vehicle as experimental object, this paper discussed the variation discipline and curves involving sliding speed, sliding time and fuel consumption rate based on various sliding tests, especially analyzed the fuel consumption difference of sliding in neutral and sliding in different gears. Finally, following conclusions are achieved: the average fuel consumption rate while vehicle sliding in different gears is similar, which is about to 1/50 of sliding in neutral’. While sliding, the vehicle’s fuel consumption rate basically maintains at a low level. But once the sliding speed decreases too low, the fuel consumption rate increases dramatically. Therefore, aiming at lowing fuel consumption and reducing emission discharge, vehicle sliding in gear should have priority to sliding in neutral and choosing a reasonable sliding speed range is important for reducing vehicle’s running fuel consumption and exhaust emission.

Utilisation of Cashew Seed Oil Methyl Ester in Compression Ignition Engines and its Engine Performance

Methyl ester, also called biodiesel, is an alternative fuel for diesel engine that is produced from renewable agricultural products. Biodiesel is an alkyl ester obtained from vegetable oils, waste cooking oils or animal fats via transesterification process. The three types of fuels used for the tests are pure biodiesel (BIOO), blended biodiesel (B20), which is a 20% mixture of biodiesel with 80% diesel fuel, and pure diesel fuel (100%) derived from crude petroleum. The characterised fuels were utilised in a compression ignition engine to determine their torque, power brake mean effective pressure and specific fuel consumption characteristics. From the test results obtained, the cashew seed oil methyl ester can be used in diesel engines as a substitute fuel. The results of this study were quite encouraging.

Ecological Vehicle Control on Roads With Up-Down Slopes

This paper presents a novel development of an ecological (eco) driving system for running a vehicle on roads with up-down slopes. Fuel consumed in a vehicle is greatly influenced by road gradients, aside from its velocity and acceleration characteristics. Therefore, optimum control inputs can only be computed through anticipated rigorous reasoning using information concerning road terrain, model of the vehicle dynamics, and fuel consumption characteristics. In this development, a nonlinear model predictive control method with a fast optimization algorithm is implemented to derive the vehicle control inputs based on road gradient conditions obtained from digital road maps. The fuel consumption model of a typical vehicle is formulated using engine efficiency characteristics and used in the objective function to ensure fuel economy driving. The proposed eco-driving system is simulated on a typical road with various shapes of up-down slopes. Simulation results reveal the ability of the eco-driving system in significantly reducing fuel consumption of a vehicle. The fuel saving behavior is graphically illustrated, compared, and analyzed to focus on the significance of this development.

Cold start and fuel consumption of a vehicle fuelled with blends of diesel oil–soybean biodiesel–ethanol

Fuel consumption and cold start characteristics of a production vehicle fuelled with blends of N. 2 diesel oil (500ppm sulfur content), soybean biodiesel (3%,5%,10%, and 20%) and hydrous ethanol (2% and 5%) were compared. A wagon-type vehicle equipped with a four-cylinder, 1.3-l, 63kW diesel engine was tested in a cold chamber at the temperature of −5°C for the cold start tests. Fuel consumption tests were performed following the 1975 US Federal Test Procedure (FTP-75). The results showed that the cold start time was satisfactory for all fuel blends tested, but it was longer for the blend containing 20% of soybean biodiesel (B20) in comparison with the blends with lower biodiesel concentration. The cold start time also increased with increasing with increasing ethanol content in the fuel blend. Specific fuel consumption was not affected by increasing biodiesel concentration in the blend or by the use of 2% of ethanol as an additive. However, the use of 5% of ethanol concentration in the B20 blend resulted in increased specific fuel consumption.

A new equation of state for hydrogen gas

A new equation with high precision has been proposed to investigate the fuel consumption characteristics of hydrogen-fueled vehicles. This new equation is designed to calculate the hydrogen consumption of vehicles under high pressure condition. Based on data from the American National Standards Institute (ANSI), error of hydrogen consumption calculated using the new equation is less than 0.5% when hydrogen storage pressure ranges from 0.5 to 70 MPa at 298 K. When storage pressure ranges from 0.1 to 50 MPa and temperature is 48–398 K, error is still less than 0.5%, with reference to data from the National Institute of Standards and Technology (NIST). Therefore, the new equation provides a simple yet effective way of estimating the cruising range of hydrogen-fueled vehicles.

Application of Genetic Neural Network in Power Battery Charging State-of-Charge Estimation

With global non-renewable resources and environmental issues becoming more apparent, the development of new energy vehicles have become the trend of auto industry. Hybrid vehicle becomes the key development of new energy vehicles with its long distance, low pollution, low fuel consumption characteristics and so on. The battery performances directly influence the quality of the whole vehicle performance. Considering the importance of the battery state of charge (SOC) estimation and the nonlinear relationship between the battery SOC and the external characteristic, genetic algorithm (GA) and back propagation (BP) neural network are proposed. Because of the strong global search capability of the genetic algorithm and the generalization ability of BP neural network, the hybrid vehicle Ni-MH power battery GA-BP charging model is designed. In this approach, the network training speed is superior to the traditional BP network. According to the real-time data of the batteries, the optimal solution can be concluded in a short time and with high estimation precision.

On-road pollutant emission and fuel consumption characteristics of buses in Beijing

On-road emission and fuel consumption (FC) levels for Euro III and IV buses fueled on diesel and compressed natural gas (CNG) were compared, and emission and FC characteristics of buses were analyzed based on approximately 28,700 groups of instantaneous data obtained in Beijing using a portable emissions measurement system (PEMS). The experimental results revealed that NO x and PM emissions from CNG buses were decreased by 72.0% and 82.3% respectively, compared with Euro IV diesel buses. Similarly, these emissions were reduced by 75.2% and 96.3% respectively, compared with Euro III diesel buses. In addition, CO 2, CO, HC, NO X, PM emissions and FC of Euro IV diesel buses were reduced by 26.4%, 75.2%, 73.6%, 11.4%, 79.1%, and 26.0%, respectively, relative to Euro III diesel buses. The CO 2, CO, HC, NO x, PM emissions and FC factors all decreased with bus speed increased, while increased as bus acceleration increased. At the same time, the emission/FC rates as well as the emission/FC factors exhibited a strong positive correlation with the vehicle specific power (VSP). They all were the lowest when VSP < 0, and then rapidly increased as VSP increased. Furthermore, both the emission/FC rates and emission/FC factors were the highest at accelerations, higher at cruise speeds, and the lowest at decelerations for non-idling buses. These results can provide a base reference to further estimate bus emission and FC inventories in Beijing.