Global ETD Search

1	Measuring the cost-effectiveness of idle reduction technologies in heavy-duty trucks Prabhakar, Niranjani 07 January 2016 (has links) The main objective of idle reduction devices is to reduce the amount of energy wasted by idling trucks, decrease exhaust emissions and save in fuel use and maintenance costs and vehicle life extension. To achieve reductions emissions from vehicle idling in heavy-duty trucks, strategies and actions have been employed through the use of various technologies, namely auxiliary power units (APUs), direct-fire heaters (DFHs), truck stop electrification (TSE) and advanced truck stop electrification (ATSE). Little quantitative data exists on the amount of emissions that are emitted by heavy-duty trucks during idling. In general, diesel engines emit less CO and hydrocarbons (HC) when compared to gasoline engines since fuel-lean mixtures tend to reduce CO and HC emissions. The purpose of this study is to conduct a systematic review that illustrates the status of data present in literature for costs and emissions reduced for APUs, DFHs, TSEs and ATSEs. From the review process, a cost calculator was devised from the synthesis of literature data to measure cost-effectiveness of these technologies in dollars per year per ton per year of emissions reduced over a 30 year investment period. Data on capital costs, maintenance and operational costs, and fuel costs were reported in order to calculate net present values, payback periods and fuel savings from each technology. Given the relevant data available from various studies that compute the efficiency of competing technologies, TSEs were the most cost-effective for the investor and the truck owner in regards to NOx emissions reduction. Cost-effectiveness measured for investors at $1,707.57 and $1,473.27 per ton of NOx reduced, and $16,799.91, $22,261.44, and $20,583.79 per ton of NOx reduced for truck owners. The calculator also served as a tool to illustrate insufficient data currently present in the body of literature. Limited quantitative data and unknown variability of costs as a function of time over the 30-year investment period was used to assess best practices. Thus, policymakers and other stakeholders can benefit from this review in order to conduct future studies that would enlighten greater understanding of data points from specifications of the operating context and devise more robust models for the sake of comparing these technologies based on impact and risk Emissions Trucks Fuel Idling
2	Hydrogen generation from dimethyl ether by autothermal reforming Nilsson, Marita January 2007 (has links) <p>Heavy-duty trucks are in idle operation during long periods of time, providing the vehicles with electricity via the alternator at standstill. Idling trucks contribute to large amounts of emissions and high fuel consumption as a result of the low efficiency from fuel to electricity. Truck manufacturers are working to develop equipment using auxiliary power units to supply the trucks with electricity, which operate independently of the main engine. Fuel cell-based auxiliary power units could offer high efficiencies and low noise and vibrations. The hydrogen required for the fuel cell can be generated in an onboard fuel reformer. This thesis is devoted to hydrogen generation from dimethyl ether, DME, by autothermal reforming focusing on the application of fuel cell auxiliary power units. In the search for alternative fuels, DME has lately been identified as a promising diesel substitute.</p><p>The first part of the thesis gives an introduction to the field of DME reforming with a literature survey of recent studies within the area. Included are also results from thermodynamic equilibrium calculations.</p><p>In the following parts of the thesis, experimental studies on autothermal reforming of DME are presented. A reformer constructed to generate hydrogen to feed a 5 kW<sub>e</sub> polymer electrolyte fuel cell is evaluated with emphasis on trying to work close to a practically viable process, i.e. without external heating and using gas mixtures resembling real conditions. Additional experiments have been conducted to investigate the use of catalytic oxidation of dimethyl ether as a heat source during startup. The results of these studies are presented in Paper I.</p><p>In the second experimental study of this thesis, which is presented in Paper II, Pd-based monolithic catalysts are evaluated at small scale for use in autothermal reforming of DME. A screening of various catalyst materials has been performed followed by a study of the influence on the product composition of varying operating parameters such as oxygen-to-DME ratio, steam-to-DME ratio, and temperature.</p> autothermal reforming auxiliary power unit dimethyl ether fuel cell hydrogen palladium reforming catalyst temperature-programmed reduction truck idling X-ray diffraction zinc Chemical engineering Kemiteknik
3	Hydrogen generation from dimethyl ether by autothermal reforming Nilsson, Marita January 2007 (has links) Heavy-duty trucks are in idle operation during long periods of time, providing the vehicles with electricity via the alternator at standstill. Idling trucks contribute to large amounts of emissions and high fuel consumption as a result of the low efficiency from fuel to electricity. Truck manufacturers are working to develop equipment using auxiliary power units to supply the trucks with electricity, which operate independently of the main engine. Fuel cell-based auxiliary power units could offer high efficiencies and low noise and vibrations. The hydrogen required for the fuel cell can be generated in an onboard fuel reformer. This thesis is devoted to hydrogen generation from dimethyl ether, DME, by autothermal reforming focusing on the application of fuel cell auxiliary power units. In the search for alternative fuels, DME has lately been identified as a promising diesel substitute. The first part of the thesis gives an introduction to the field of DME reforming with a literature survey of recent studies within the area. Included are also results from thermodynamic equilibrium calculations. In the following parts of the thesis, experimental studies on autothermal reforming of DME are presented. A reformer constructed to generate hydrogen to feed a 5 kWe polymer electrolyte fuel cell is evaluated with emphasis on trying to work close to a practically viable process, i.e. without external heating and using gas mixtures resembling real conditions. Additional experiments have been conducted to investigate the use of catalytic oxidation of dimethyl ether as a heat source during startup. The results of these studies are presented in Paper I. In the second experimental study of this thesis, which is presented in Paper II, Pd-based monolithic catalysts are evaluated at small scale for use in autothermal reforming of DME. A screening of various catalyst materials has been performed followed by a study of the influence on the product composition of varying operating parameters such as oxygen-to-DME ratio, steam-to-DME ratio, and temperature. / QC 20101115 autothermal reforming auxiliary power unit dimethyl ether fuel cell hydrogen palladium reforming catalyst temperature-programmed reduction truck idling X-ray diffraction zinc Chemical Engineering Kemiteknik
4	Operational optimisation of water distribution networks Lopez-Ibanez, Manuel January 2009 (has links) Water distribution networks are a fundamental part of any modern city and their daily operations constitute a significant expenditure in terms of energy and maintenance costs. Careful scheduling of pump operations may lead to significant energy savings and prevent wear and tear. By means of computer simulation, an optimal schedule of pumps can be found by an optimisation algorithm. The subject of this thesis is the study of pump scheduling as an optimisation problem. New representations of pump schedules are investigated for restricting the number of potential schedules. Recombination and mutation operators are proposed, in order to use the new representations in evolutionary algorithms. These new representations are empirically compared to traditional representations using different network instances, one of them being a large and complex network from UK. By means of the new representations, the evolutionary algorithm developed during this thesis finds new best-known solutions for both networks. Pump scheduling as the multi-objective problem of minimising energy and maintenance costs in terms of Pareto optimality is also investigated in this thesis. Two alternative surrogate measures of maintenance cost are considered: the minimisation of the number of pump switches and the maximisation of the shortest idle time. A single run of the multi-objective evolutionary algorithm obtains pump schedules with lower electrical cost and lower number of pump switches than those found in the literature. Alternatively, schedules with very long idle times may be found with slightly higher electrical cost. Finally, ant colony optimisation is also adapted to the pump scheduling problem. Both Ant System and Max-Min Ant System are tested. Max-Min Ant System, in particular, outperforms all other algorithms in the large real-world network instance and obtains competitive results in the smallest test network. Computation time is further reduced by parallel simulation of pump schedules. 627
5	CONSTRUCTION EQUIPMENT FUEL CONSUMPTION DURING IDLING : Characterization using multivariate data analysis at Volvo CE Hassani, Mujtaba January 2020 (has links) Human activities have increased the concentration of CO2 into the atmosphere, thus it has caused global warming. Construction equipment are semi-stationary machines and spend at least 30% of its life time during idling. The majority of the construction equipment is diesel powered and emits toxic emission into the environment. In this work, the idling will be investigated through adopting several statistical regressions models to quantify the fuel consumption of construction equipment during idling. The regression models which are studied in this work: Multivariate Linear Regression (ML-R), Support Vector Machine Regression (SVM-R), Gaussian Process regression (GP-R), Artificial Neural Network (ANN), Partial Least Square Regression (PLS-R) and Principal Components Regression (PC-R). Findings show that pre-processing has a significant impact on the goodness of the prediction of the explanatory data analysis in this field. Moreover, through mean centering and application of the max-min scaling feature, the accuracy of models increased remarkably. ANN and GP-R had the highest accuracy (99%), PLS-R was the third accurate model (98% accuracy), ML-R was the fourth-best model (97% accuracy), SVM-R was the fifth-best (73% accuracy) and the lowest accuracy was recorded for PC-R (83% accuracy). The second part of this project estimated the CO2 emission based on the fuel used and by adopting the NONROAD2008 model. Keywords: Idling condition environmental effect diesel fuel machine learning multivariate data analysis partial least square regression support vector machine regression principal component analysis principal component regression correlation coefficient matrix artificial neural network exhaust emission reduction techniques global warming emission regulation CO2 estimation techniques Gaussian process regression Engineering and Technology Teknik och teknologier
6	Energy Prediction in Heavy Duty Long Haul Trucks Khuntia, Satvik 22 December 2022 (has links) No description available. Engineering Automotive Engineering Statistics Systems Design Sustainability Transportation Artificial Intelligence Mechanical Engineering "Heavy Duty truck SuperTruck Hoteling hybrid idling Physics based modeling HVAC Vapor compression cycle moving boundary method heat exchanger cabin Machine Learning User activity behavior time allocation matrix transition matrix markov chain driver comfort freight efficiency RNN LSTM powertrain cooling radiator thermostat"

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