Engenharia Mecânica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/23
Navegar
2 resultados
Resultados da Pesquisa
- Optimal coordination strategy to form and dissolve truck platoons on a highway stretch(2022) DE SOUZA MENDES, A.; Fabrizio Leonardi; DE TOLEDO FLEURY, A.© 2022, The Author(s), under exclusive licence to The Brazilian Society of Mechanical Sciences and Engineering.This paper presents a coordination strategy to optimally form and dissolve N-truck platoons on a highway stretch. Truck platooning, a set of trucks driving with small inter-vehicle distances, can benefit the transportation sector by reducing the overall fuel consumption and greenhouse gas emissions while increasing traffic throughput. However, different itineraries and delivery time restrictions may limit the opportunities to from platoons on a large scale. Therefore, a coordination strategy must be capable of merging scattered trucks and splitting the platoon considering the constraints from each participant to avoid penalties. To address this issue, an optimization problem is formulated to provide optimal speed profiles for an unlimited number of trucks during the merging, platooning and splitting phases of the coordination. An equivalent single stretch representation is presented to simplify complex road networks using appropriate merging and splitting constraints. The resulting optimal speed profiles are presented for 2, 3 and 10 trucks highlighting the capability to handle different desired traveling speeds without compromising the itinerary of each truck and allowing the overtake of trucks directly in the optimization problem. Sensitivity analyses are used to investigate the savings potential according to the main parameters of the coordination. Finally, the proposed algorithm is evaluated in a simulation study using validated vehicle and consumption models with real road topography data. In a 100 km Brazilian highway stretch, scenarios with two and three scattered trucks with substantial initial separation distances are evaluated and present energy efficient maneuvers under the proposed coordination strategy.
- Thermodynamic analysis and optimization of a multi-stage compression system for CO2 injection unit: NSGA-II and gradient-based methods(2021-10-10) ALLAHYARZADEH-BIDGOLI, A.; DE MELO, P. E. B.; DEZAN, D. J.; SALTARA, F.; SALVIANO, O.; YANAGIHARA, J. I.© 2021, The Brazilian Society of Mechanical Sciences and Engineering.The injection of CO2 into oil reservoirs is used by the oil and gas industry for enhanced oil recovery (EOR) and/or the reduction of environmental impact. The compression systems used for this task work with CO2 in supercritical conditions, and the equipment used is energy intensive. The application of an optimization procedure designed to find the optimum operating conditions leads to reduced energy consumption, lower exergy destruction, and reduced CO2 emissions. First, this work presents two thermodynamic models to estimate the amount of power necessary for a multi-stage CO2 compression system in floating production storage and offloading (FPSO) using accurate polytropic relationships and equations of state. Second, a thermodynamic analysis using the first and second laws of thermodynamics is conducted to identify possible improvements in energy consumption and the sources of the compression unit’s irreversibilities. In the final step, optimization procedures, using two methods with different approaches, are implemented to minimize the total power consumption. As the number of stages and the pressure drop between them influence the total power required by the compressors, these are considered as the input parameters used to obtain the inlet pressure at each stage. Three different compositions with variations in CO2 content, i.e., pure CO2, pure CH 4, and 70% CO2 + 30% CH 4, are also investigated as three different operating scenarios. The optimal configurations and pressure ratios result in a reduction in power consumption of up to 9.65%, mitigation of CO2 emissions by up to 1.95 t/h, and savings in exergy loss of up to 23.9%, when compared with conventional operating conditions.