The Experts below are selected from a list of 1767 Experts worldwide ranked by ideXlab platform
Rodolfo Taccani - One of the best experts on this subject based on the ideXlab platform.
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A thermodynamic feasibility study of an Organic Rankine Cycle (ORC) for heavy-duty diesel engine waste heat recovery in off-highway applications
International Journal of Energy and Environmental Engineering, 2017Co-Authors: Simone Lion, Ioannis Vlaskos, Constantine N. Michos, Rodolfo TaccaniAbstract:This work assesses the possibility of fitting an organic Rankine cycle (ORC) system in a commercial agricultural tractor, recovering waste heat from a 300-kW brake power heavy-duty diesel engine. Two different cycle architectures are considered: a single evaporator layout to recover Tail-Pipe exhaust heat, and a parallel evaporator configuration to recover both exhaust and exhaust gas recirculation (EGR) heat. A second lower-temperature cooling circuit is also considered as possible different heat sink for the ORC system. Ten different working fluids have been assessed, and the optimum system configuration, in terms of fuel consumption, has been obtained applying an optimization algorithm to a process simulation model. A preliminary study has been carried out to evaluate the impact of the ORC system on the engine–vehicle-cooling system. A maximum fuel consumption reduction of 10.6% has been obtained using methanol and recovering heat from Tail-Pipe and EGR. However, considering also components and heat rejection performance, water steam, toluene and ethanol allow to obtain the best compromises between thermodynamic performance and engine–vehicle-cooling circuit impact.
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Analysis of the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged heavy duty diesel power generator for marine applications
Energy Conversion and Management, 2017Co-Authors: Constantine N. Michos, Simone Lion, Ioannis Vlaskos, Rodolfo TaccaniAbstract:In marine and power generation sectors, waste heat recovery technologies are attracting growing attention in order to increase heavy duty diesel engines efficiency and decrease fuel consumption, with the purpose of respecting stringent emissions legislations. In this work, the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged, V12 heavy duty diesel engine, for typical marine and power generation applications has been investigated using the commercial software Ricardo WAVE. Three different state-of-the art turbocharging strategies are assessed in order to counterbalance the increased pumping losses of the engine due to the boiler installation: fixed turbine, Waste-Gate (WG) and Variable Geometry Turbine (VGT). At the same time, the steady-state thermodynamic performance of two different ORC configurations, simple Tail-Pipe evaporator and recuperated simple Tail-Pipe evaporator layouts, are assessed, with the scope of further increasing the engine power output, recovering unutilized exhaust gas heat. Several different working fluids, suitable for medium-high temperature waste heat recovery, are evaluated and screened, considering, as well, health and safety issues. Thermodynamic cycle parameters such as, for example, evaporation and condensing pressures, working fluid mass flow and cycle temperatures, are optimized in order to obtain the maximum improvement in Brake Specific Fuel Consumption (bsfc). From the engine side point of view, a VGT turbocharger is the most favorable solution to withstand increased backpressure, while, regarding the ORC side, between the considered fluids and layouts, acetone and a recuperated cycle show the most promising performance.
Simone Lion - One of the best experts on this subject based on the ideXlab platform.
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A thermodynamic feasibility study of an Organic Rankine Cycle (ORC) for heavy-duty diesel engine waste heat recovery in off-highway applications
International Journal of Energy and Environmental Engineering, 2017Co-Authors: Simone Lion, Ioannis Vlaskos, Constantine N. Michos, Rodolfo TaccaniAbstract:This work assesses the possibility of fitting an organic Rankine cycle (ORC) system in a commercial agricultural tractor, recovering waste heat from a 300-kW brake power heavy-duty diesel engine. Two different cycle architectures are considered: a single evaporator layout to recover Tail-Pipe exhaust heat, and a parallel evaporator configuration to recover both exhaust and exhaust gas recirculation (EGR) heat. A second lower-temperature cooling circuit is also considered as possible different heat sink for the ORC system. Ten different working fluids have been assessed, and the optimum system configuration, in terms of fuel consumption, has been obtained applying an optimization algorithm to a process simulation model. A preliminary study has been carried out to evaluate the impact of the ORC system on the engine–vehicle-cooling system. A maximum fuel consumption reduction of 10.6% has been obtained using methanol and recovering heat from Tail-Pipe and EGR. However, considering also components and heat rejection performance, water steam, toluene and ethanol allow to obtain the best compromises between thermodynamic performance and engine–vehicle-cooling circuit impact.
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Analysis of the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged heavy duty diesel power generator for marine applications
Energy Conversion and Management, 2017Co-Authors: Constantine N. Michos, Simone Lion, Ioannis Vlaskos, Rodolfo TaccaniAbstract:In marine and power generation sectors, waste heat recovery technologies are attracting growing attention in order to increase heavy duty diesel engines efficiency and decrease fuel consumption, with the purpose of respecting stringent emissions legislations. In this work, the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged, V12 heavy duty diesel engine, for typical marine and power generation applications has been investigated using the commercial software Ricardo WAVE. Three different state-of-the art turbocharging strategies are assessed in order to counterbalance the increased pumping losses of the engine due to the boiler installation: fixed turbine, Waste-Gate (WG) and Variable Geometry Turbine (VGT). At the same time, the steady-state thermodynamic performance of two different ORC configurations, simple Tail-Pipe evaporator and recuperated simple Tail-Pipe evaporator layouts, are assessed, with the scope of further increasing the engine power output, recovering unutilized exhaust gas heat. Several different working fluids, suitable for medium-high temperature waste heat recovery, are evaluated and screened, considering, as well, health and safety issues. Thermodynamic cycle parameters such as, for example, evaporation and condensing pressures, working fluid mass flow and cycle temperatures, are optimized in order to obtain the maximum improvement in Brake Specific Fuel Consumption (bsfc). From the engine side point of view, a VGT turbocharger is the most favorable solution to withstand increased backpressure, while, regarding the ORC side, between the considered fluids and layouts, acetone and a recuperated cycle show the most promising performance.
Constantine N. Michos - One of the best experts on this subject based on the ideXlab platform.
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A thermodynamic feasibility study of an Organic Rankine Cycle (ORC) for heavy-duty diesel engine waste heat recovery in off-highway applications
International Journal of Energy and Environmental Engineering, 2017Co-Authors: Simone Lion, Ioannis Vlaskos, Constantine N. Michos, Rodolfo TaccaniAbstract:This work assesses the possibility of fitting an organic Rankine cycle (ORC) system in a commercial agricultural tractor, recovering waste heat from a 300-kW brake power heavy-duty diesel engine. Two different cycle architectures are considered: a single evaporator layout to recover Tail-Pipe exhaust heat, and a parallel evaporator configuration to recover both exhaust and exhaust gas recirculation (EGR) heat. A second lower-temperature cooling circuit is also considered as possible different heat sink for the ORC system. Ten different working fluids have been assessed, and the optimum system configuration, in terms of fuel consumption, has been obtained applying an optimization algorithm to a process simulation model. A preliminary study has been carried out to evaluate the impact of the ORC system on the engine–vehicle-cooling system. A maximum fuel consumption reduction of 10.6% has been obtained using methanol and recovering heat from Tail-Pipe and EGR. However, considering also components and heat rejection performance, water steam, toluene and ethanol allow to obtain the best compromises between thermodynamic performance and engine–vehicle-cooling circuit impact.
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Analysis of the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged heavy duty diesel power generator for marine applications
Energy Conversion and Management, 2017Co-Authors: Constantine N. Michos, Simone Lion, Ioannis Vlaskos, Rodolfo TaccaniAbstract:In marine and power generation sectors, waste heat recovery technologies are attracting growing attention in order to increase heavy duty diesel engines efficiency and decrease fuel consumption, with the purpose of respecting stringent emissions legislations. In this work, the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged, V12 heavy duty diesel engine, for typical marine and power generation applications has been investigated using the commercial software Ricardo WAVE. Three different state-of-the art turbocharging strategies are assessed in order to counterbalance the increased pumping losses of the engine due to the boiler installation: fixed turbine, Waste-Gate (WG) and Variable Geometry Turbine (VGT). At the same time, the steady-state thermodynamic performance of two different ORC configurations, simple Tail-Pipe evaporator and recuperated simple Tail-Pipe evaporator layouts, are assessed, with the scope of further increasing the engine power output, recovering unutilized exhaust gas heat. Several different working fluids, suitable for medium-high temperature waste heat recovery, are evaluated and screened, considering, as well, health and safety issues. Thermodynamic cycle parameters such as, for example, evaporation and condensing pressures, working fluid mass flow and cycle temperatures, are optimized in order to obtain the maximum improvement in Brake Specific Fuel Consumption (bsfc). From the engine side point of view, a VGT turbocharger is the most favorable solution to withstand increased backpressure, while, regarding the ORC side, between the considered fluids and layouts, acetone and a recuperated cycle show the most promising performance.
Ioannis Vlaskos - One of the best experts on this subject based on the ideXlab platform.
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A thermodynamic feasibility study of an Organic Rankine Cycle (ORC) for heavy-duty diesel engine waste heat recovery in off-highway applications
International Journal of Energy and Environmental Engineering, 2017Co-Authors: Simone Lion, Ioannis Vlaskos, Constantine N. Michos, Rodolfo TaccaniAbstract:This work assesses the possibility of fitting an organic Rankine cycle (ORC) system in a commercial agricultural tractor, recovering waste heat from a 300-kW brake power heavy-duty diesel engine. Two different cycle architectures are considered: a single evaporator layout to recover Tail-Pipe exhaust heat, and a parallel evaporator configuration to recover both exhaust and exhaust gas recirculation (EGR) heat. A second lower-temperature cooling circuit is also considered as possible different heat sink for the ORC system. Ten different working fluids have been assessed, and the optimum system configuration, in terms of fuel consumption, has been obtained applying an optimization algorithm to a process simulation model. A preliminary study has been carried out to evaluate the impact of the ORC system on the engine–vehicle-cooling system. A maximum fuel consumption reduction of 10.6% has been obtained using methanol and recovering heat from Tail-Pipe and EGR. However, considering also components and heat rejection performance, water steam, toluene and ethanol allow to obtain the best compromises between thermodynamic performance and engine–vehicle-cooling circuit impact.
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Analysis of the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged heavy duty diesel power generator for marine applications
Energy Conversion and Management, 2017Co-Authors: Constantine N. Michos, Simone Lion, Ioannis Vlaskos, Rodolfo TaccaniAbstract:In marine and power generation sectors, waste heat recovery technologies are attracting growing attention in order to increase heavy duty diesel engines efficiency and decrease fuel consumption, with the purpose of respecting stringent emissions legislations. In this work, the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged, V12 heavy duty diesel engine, for typical marine and power generation applications has been investigated using the commercial software Ricardo WAVE. Three different state-of-the art turbocharging strategies are assessed in order to counterbalance the increased pumping losses of the engine due to the boiler installation: fixed turbine, Waste-Gate (WG) and Variable Geometry Turbine (VGT). At the same time, the steady-state thermodynamic performance of two different ORC configurations, simple Tail-Pipe evaporator and recuperated simple Tail-Pipe evaporator layouts, are assessed, with the scope of further increasing the engine power output, recovering unutilized exhaust gas heat. Several different working fluids, suitable for medium-high temperature waste heat recovery, are evaluated and screened, considering, as well, health and safety issues. Thermodynamic cycle parameters such as, for example, evaporation and condensing pressures, working fluid mass flow and cycle temperatures, are optimized in order to obtain the maximum improvement in Brake Specific Fuel Consumption (bsfc). From the engine side point of view, a VGT turbocharger is the most favorable solution to withstand increased backpressure, while, regarding the ORC side, between the considered fluids and layouts, acetone and a recuperated cycle show the most promising performance.
John E Dec - One of the best experts on this subject based on the ideXlab platform.
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2016Co-Authors: John E Dec, Jay O KellerAbstract:The cyclic behavior of the oscillating velocity field in the Tail Pipe of a pulse combustor was studied using laser doppler velocimetry. In this flow, the oscillations result from an acoustic resonance and have amplitudes of up to 5 times the mean velocity. Oscillation frequencies were varied from 67 to 101 Hz. Streamwise velocity and turbulence-intensity boundary layer profiles were measured to within 130 #m of the wall, and transverse turbulence measurements were made to within 2 ram. The phase relationships of the velocity, turbulence intensity, and combustion chamber pressure oscillations are compared. Velocity oscillations near the wall are found to phase lead those in the center of the Pipe, creating periodic flow reversals through the boundary layer. A comparison is made between this turbulent oscillating boundary layer and the laminar oscillating boundary layer for flow over a flat plate. The effects of axial position, pulsation frequency, pulsation amplitude, and mean flow rate on the velocity and turbulence profiles are discussed. Time-resolved wall shear stresses (directly calculated from the velocity measurements) are presented and compared with those of steady turbulent flow. Time-averaged velocity and turbulence profiles are also compared with those of conventional steady turbulent flows. The time-averaged velocity profile is found to be flatter than that of steady flow at the same mean Reynolds number, and both the streamwise and transverse turbulence intensities are found to be significantly higher than those of steady flow. NOMENCLATURE D hydraulic diameter P pressure P~ms combustion chamber pressure, mean square about he mean roo
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heat transfer enhancement in the oscillating turbulent flow of a pulse combustor Tail Pipe
International Journal of Heat and Mass Transfer, 1992Co-Authors: John E Dec, Jay O Keller, Vedat S ArpaciAbstract:Abstract Heat transfer rates in pulse combustor Tail Pipes and in other reversing, oscillating, turbulent flows have been found to be much higher than those of steady turbulent flow. To elucidate the mechanisms of the enhancement, the temperature and velocity fields, measured with two-line atomic fluorescence (TLAF) and laser Doppier velocimetry (LDV), respectively, are compared. Time-resolved wall heat fluxes and Nusselt numbers are also presented and discussed. Possible causes for the heat transfer enhancement in oscillating flows are reviewed and discussed in view of the data presented in this paper and the recent literature.
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time resolved velocities and turbulence in the oscillating flow of a pulse combustor Tail Pipe
Combustion and Flame, 1991Co-Authors: John E Dec, Jay O Keller, Ichiro HongoAbstract:Abstract The cyclic behavior of the oscillating velocity field in the Tail Pipe of a pulse combustor was studied using laser doppler velocimetry. In this flow, the oscillations result from an acoustic resonance and have amplitudes of up to 5 times the mean velocity. Oscillation frequencies were varied from 67 to 101 Hz. Streamwise velocity and turbulence-intensity boundary layer profiles were measured to within 130 μm of the wall, and transverse turbulence measurements were made to within 2 mm. The phase relationships of the velocity, turbulence intensity, and combustion chamber pressure oscillations are compared. Velocity oscillations near the wall are found to phase lead those in the center of the Pipe, creating periodic flow reversals through the boundary layer. A comparison is made between this turbulent oscillating boundary layer and the laminar oscillating boundary layer for flow over a flat plate. The effects of axial position, pulsation frequency, pulsation amplitude, and mean flow rate on the velocity and turbulence profiles are discussed. Time-resolved wall shear stresses (directly calculated from the velocity measurements) are presented and compared with those of steady turbulent flow. Time-averaged velocity and turbulence profiles are also compared with those of conventional steady turbulent flows. The time-averaged velocity profile is found to be flatter than that of steady flow at the same mean Reynolds number, and both the streamwise and transverse turbulence intensities are found to be significantly higher than those of steady flow.
