20 documents found, page 1 of 2
Turpentine as an additive for diesel engines: experimental study on pollutant e...
Chivu, Robert Mădălin; Martins, Jorge; Popescu, Florin; Uzuneanu, Krisztina; Ion, Ion V.; Gonçalves, Margarida; Codau, Teodor Cezar; Onofrei, ElenaThe need for reducing fossil fuel consumption and greenhouse gas (GHG) emissions in internal combustion engines has raised the opportunity for the use of renewable energy sources. For the progressive replacement of fossil fuels like diesel, those derived from the sustainable management of forest resources may be a good option. In Portugal, pine trees (pinus pinaster) are among the most widely cultivated tree sp...
Assessment of an exhaust thermoelectric generator incorporating thermal control...
Sousa, Carolina Clasen; Martins, Jorge; Carvalho, Óscar Samuel Novais; Coelho, Miguel Granja Pinheiro; Moita, Ana Sofia; Brito, F.P.The road transport industry faces the need to develop its fleet for lower energy consumption, pollutants and CO<sub>2</sub> emissions. Waste heat recovery systems with Thermoelectric Generators (TEGs) can directly convert the exhaust heat into electric energy, aiding the electrical needs of the vehicle, thus reducing its dependency on fuel energy. The present work assesses the optimisation and evaluation of a t...
Complex fluid flow in microchannels and heat pipes with enhanced surfaces for a...
Moita, Ana Sofia; Pontes, Pedro; Martins, Lourenço; Coelho, Miguel Granja Pinheiro; Carvalho, Óscar Samuel Novais; Brito, F.P.; Moreira, António Luís N.This paper addresses a multiscale approach for heat recovery systems, used in two distinct applications. In both applications, a microscale approach is used (microchannel heat sinks and heat pipes) for macroscale applications (cooling of a photovoltaic—PV cell), and the thermal energy of exhaust gases of an internal combustion engine is used for thermoelectric generators with variable conductance heat pipes. Se...
Experimental assessment of the performance and emissions of a spark-ignition en...
Costa, Joaquim; Martins, Jorge; Arantes, Tiago; Gonçalves, Margarida; Durão, Luis; Brito, F.P.The use of biofuels for spark ignition engines is proposed to diversify fuel sources and reduce fossil fuel consumption, optimize engine performance, and reduce pollutant emissions. Additionally, when these biofuels are produced from low-grade wastes, they constitute valorisation pathways for these otherwise unprofitable wastes. In this study, ethanol and pyrolysis biogasoline made from low-grade wastes were ev...
Analysis and design of a silicide-tetrahedrite thermoelectric generator concept...
Brito, F.P.; Peixoto, João Silva; Martins, Jorge; Gonçalves, António P.; Louca, Loucas; Vlachos, Nikolaos; Kyratsi, TheodoraIndustrial Waste Heat Recovery (IWHR) is one of the areas with strong potential for energy efficiency and emissions reductions in industry. Thermoelectric (TE) generators (TEGs) are among the few technologies that are intrinsically modular and can convert heat directly into electricity without moving parts, so they are nearly maintenance-free and can work unattended for long periods of time. However, most exist...
Improvement of biocomposite performance under low-velocity impact test - a review
Sanivada, Usha Kiran Kumar; Dolores, Gonzalo Mármol de Los; Brito, F.P.; Fangueiro, RaúlThe study of the impact energy and the composite behaviour plays a vital role in the efficient design of composite structures. Among the various categories of impact tests, it is essential to study low-velocity impact tests as the damage generated due to these loads is often not visible to the naked eye. The internal damages can reduce the strength of the composites and hence the impact behaviour must be addres...
Efficiency improvement of vehicles using temperature controlled exhaust thermoe...
Brito, F.P.; Pacheco, N.; Vieira, R.; Martins, Jorge; Martins, Luís Barreiros; Teixeira, J. Carlos; Gonçalves, L. M.; Oliveira, J.; Hall, M. J.One of the main obstacles for the use of thermoelectric generators (TEGs) in vehicles is the highly variable thermal loads typical of driving cycles. Under these conditions it will be virtually impossible for a conventional heat exchanger to avoid both thermal dilution under low thermal loads and TEG overheating under high thermal loads. The authors have been exploring an original heat exchanger concept able to...
Performance and emissions of a spark ignition engine operated with gasoline sup...
Durão, Luís; Costa, Joaquim; Arantes, Tiago; Brito, F.P.; Martins, Jorge; Gonçalves, MargaridaThe partial replacement of fossil fuels by biofuels contributes to a reduction of CO<sub>2</sub> emissions, alleviating the greenhouse effect and climate changes. Furthermore, fuels produced from waste biomass materials have no impact on agricultural land use and reduce deposition of such wastes in landfills. In this paper we evaluate the addition of pyrolysis biogasoline (pyrogasoline) as an additive for fossi...
Improvement of biocomposite performance under low velocity impact test - a review
Sanivada, Usha Kiran; Mármol, Aka G.; Brito, F.P.; Fangueiro, RaúlThe study of the impact energy and the composite behavior plays a vital role in the efficient design of the composite structures. Among the various categories of impact tests, it is essential to study low velocity impact tests as the damage generated due to these loads is often not visible to the naked eye. The internal damages can reduce the strength of the composites and hence the impact behavior must be addr...
Compact automotive thermoelectric generator with embedded heat pipes for therma...
Pacheco, N.; Brito, F.P.; Vieira, R.; Martins, Jorge; Barbosa, H.; Gonçalves, L. M.Currently, the automotive industry faces challenges to implement solutions that provide reductions in energy consumption, pollutants and greenhouse-gas (GHG) emissions. Exhaust heat recovery employing Thermoelectric generators (TEGs) enables the direct conversion of heat into electric energy without moving parts and little to no maintenance. On-board electrical production is especially useful given the growing ...