The heated fluid is then fed into the expander unit, where a generator converts the thermal energy into AC electrical energy. The e-WHR is based on the Rankine Cycle and uses an evaporator to heat a fluid with the heat from the vehicle exhaust gas. The electric Waste Heat Recovery (e-WHR) converts the heat from the vehicle exhaust system into electrical energy, and so helps to improve the efficiency. During high way use-cases the vehicle is able to stop the internal combustion engine and fully drive on the E-machine thereby eliminating the internal friction from the engine and thus saving additional fuel. As the e-motor was designed for passenger cars, the peak output currents from the inverter is too low for a heavy duty vehicle to drive-off fully electric from standstill, and therefor it needs the internal combustion engine to assist. The e-motor is strong enough to fully drive the heavy duty truck, without support from the internal combustion engine. The electric motor is a permanent magnet synchronous machine, with a mechanical peak power of 100 kW, a peak torque of 250 Nm and an integrated reduction transmission bringing the peak torque at 750 Nm. Nonetheless, the E-machine and the dedicated inverter have been developed with the ECOCHAMPS philosophy to be compliant with the overall goals, using standardized components of the passenger car industry.
The electric motor is developed outside the ECOCHAMPS project. The main targets of the demonstrator are listed in below. The costs are addressed by applying standardized, modular hybrid components that were developed for high volume produced passenger car components, based on the established 400 V technology. A delay in response time of thermodynamic systems, such as the waste heat recovery system, results in a delay in the availability of thermal energy that is converted to drive power, reducing the potential of the waste heat recovery system. This enables the hybrid system to use the stored energy at a later moment or to use it directly for auxiliary power supply, resulting in an improvement of the overall fuel economy. The combination of a waste heat recovery system with the hybrid system offers freedom to store the generated energy from otherwise wasted heat. The energy management system optimizes the trade-off between using the combustion engine, auxiliaries and electric motor, minimizing the overall energy losses. Increased powertrain efficiency is gained from downsizing of the combustion engine and the hybrid electric components.
To address these challenges, the heavy duty truck demonstrator has a parallel hybrid powertrain and a combined waste heat recovery system. For these reasons, the heavy duty truck demonstrator is focusing on a significant driveline efficiency improvement with minimized cost increase. On top of that, the European Commission has set challenging targets on the CO 2 emissions of Heavy Duty Vehicles in 20. The customers in the heavy duty vehicle market are asking for low fuel consumption, as it is one of the key factors in the vehicle Total Cost of Ownership.
0 kommentar(er)
