Suchergebnisse

International audience ; Increasing fuel prizes, future CO2 emission legislation as well as new powertrain architectures are the main factors for truck manufacturers to invest into fuel saving technologies. Especially for long haul heavy duty transport and high mean engine loads, Rankine cycle waste heat recovery can lead to significant fuel savings. In this study transient road cycle simulations are performed to compare different Rankine architectures, coupled to a mild hybrid driveline, using tailpipe heat as heat source and ethanol as working fluid. The results show better performance for the indirect cooling strategy. Furthermore the multi-model proportional integral controller is considered as the best controller to fulfill the requirements about safety and performance.

International audience ; Increasing fuel prizes, future CO2 emission legislation as well as new powertrain architectures are the main factors for truck manufacturers to invest into fuel saving technologies. Especially for long haul heavy duty transport and high mean engine loads, Rankine cycle waste heat recovery can lead to significant fuel savings. In this study transient road cycle simulations are performed to compare different Rankine architectures, coupled to a mild hybrid driveline, using tailpipe heat as heat source and ethanol as working fluid. The results show better performance for the indirect cooling strategy. Furthermore the multi-model proportional integral controller is considered as the best controller to fulfill the requirements about safety and performance.

International audience ; Increasing fuel prizes, future CO2 emission legislation as well as new powertrain architectures are the main factors for truck manufacturers to invest into fuel saving technologies. Especially for long haul heavy duty transport and high mean engine loads, Rankine cycle waste heat recovery can lead to significant fuel savings. In this study transient road cycle simulations are performed to compare different Rankine architectures, coupled to a mild hybrid driveline, using tailpipe heat as heat source and ethanol as working fluid. The results show better performance for the indirect cooling strategy. Furthermore the multi-model proportional integral controller is considered as the best controller to fulfill the requirements about safety and performance.

International audience ; Increasing fuel prizes, future CO2 emission legislation as well as new powertrain architectures are the main factors for truck manufacturers to invest into fuel saving technologies. Especially for long haul heavy duty transport and high mean engine loads, Rankine cycle waste heat recovery can lead to significant fuel savings. In this study transient road cycle simulations are performed to compare different Rankine architectures, coupled to a mild hybrid driveline, using tailpipe heat as heat source and ethanol as working fluid. The results show better performance for the indirect cooling strategy. Furthermore the multi-model proportional integral controller is considered as the best controller to fulfill the requirements about safety and performance.

Driven by future emissions legislations and increase in fuel prices engine, gas heat recovering has recently attracted a lot of interest. In the past few years, a high number of studies have shown the interest of energy recovery Rankine based systems for heavy duty trucks engine compounding. Recent studies have brought a significant potential for such a system in a Heavy Duty (HD) vehicle, which can lead to a decrease in fuel consumption of about 5% [Wang et al. (2011)] and reduce engine emissions. But many challenges still need to be faced before the vehicle integration. This paper presents a control strategy development for waste heat recovery Rankine based systems in heavy duty trucks. Due to the highly transient operating conditions, improving the control strategy of those systems is an important step to their integration into a vehicle. It is shown here that moving to more advanced control strategies than classical PIDs lead to some gains in terms of performance. Due to the limited availability and high operational cost of test bench, the validation of such a controller is done on a representative and previously validated model. ; Peer reviewed

Under the economic and political pressure due to the depletion of fossil fuels and global warming concerns, it is necessary to develop more sustainable techniques to provide electrical power. In this context, the present study aims at designing, building and testing a small-scale organic Rankine cycle (ORC) solar power plant ( 3 kWe) in order to define and optimize control strategies that could be applied to larger systems. This paper presents a first step of the design of the solar power plant and focuses more specifically on the ORC engine. This design is defined on the basis of simulation models of the ORC engine and takes into account some technical limitations such as the allowed operating ranges and the technical maturity of the components. The final configuration includes a diaphragm pump, two plate heat exchangers for the regenerator and the evaporator, an air-cooled condenser, two hermetic scroll expanders in series and R245fa as the working fluid. Simulations indicate that an efficiency close to 12% for the ORC engine can be reached for evaporating and condensing temperatures of 140 and 358C, respectively. ; Peer reviewed