|The new TCe 130.|
In a series of announcements related to environmental performance, Renault introduced a new downsized, charged gasoline engine in its TCe line (earlier post), the TCe 130. With a low-inertia turbocharger, this 1.4-liter engine delivers the power of a 1.8-liter and the torque of a 2-liter engine for the fuel consumption of a 1.6-liter unit.
Renault also introduced the Scénic ZEV H2 fuel cell hybrid vehicle prototype, a joint project of the Nissan-Renault Alliance. Nissan supplied the fuel cell stack, the high-pressure hydrogen tank, and lithium-ion batteries. Renault repackaged the Grand Scénic to enable the underbody to incorporate the fuel cell stack, tank and batteries.
Other announcements included the development of a new NOx trap and a driver-oriented project: Renault will offer its customers environmental driving lessons with simulators installed in dealerships by the end of 2008. Renault also highlighted its EV work and the partnership with Project Better Place to mass market EVs in Israel and Denmark by 2011. (Earlier post.)
|Power and torque for the TCe 130. Click to enlarge.|
The TCe 130. Developed as part of the Nissan-Renault Alliance, the TCe 130 is derived from the normally aspirated HR15 and HR16 engines (the 1.5 and 1.6-liter units in the Nissan line-up).
The new engine delivers maximum power of 96 kW (130 hp) at 5,500 rpm and torque of 190 Nm (140 lb-ft) at 2,250 rpm; it will be applied in Renault C-segment vehicles.
The new TCe 130 has an aluminium sump and a single-flow turbocompressor. The profile of its inlet ports has been redesigned compared with those of the normally-aspirated engine. The new ports create a swirling inflow, which mixes fuel and air more evenly, so improving combustion.
Due to the tumbling flow of air, the combustion flame propagates more efficiently, improving torque at low revs without impairing performance at higher engine speeds. A continuous camshaft angle variator at the intake port improves performance at all engine speeds and helps reduce fuel consumption. The engine has a timing chain that which not only cuts noise but is also reliable and durable.
The TCe 130 will be paired with a six-speed manual gearbox.
|Scénic ZEV H2 prototype. Click to enlarge.|
The Scénic ZEV H2 prototype. In 2006, Renault and Nissan decided to pool their efforts to produce a demonstration vehicle powered by a fuel cell that drew on Alliance technologies. Scénic ZEV H2 was designed in just 15 months, testing included.
The first vehicle kicked off in France in the summer of 2007. After a joint check, the first prototype was then transferred to Japan for final assembly. At the end of 2007, the first vehicle was on the road. The project reached completion at the end of April 2008 once all fine-tuning had been finalized.
The ZEV H2 is driven by a 90 kW asynchronous electric motor and a 400V, 25 kW output lithium-ion battery. The stack is fueled by compressed hydrogen stored at 350 bar. Top speed of the 5-seat Scénic ZEV H2 is approximately 160 kph (99 mph), with acceleration from 0 to 100 kph of 14.65 seconds. Range is approximately 350 km (217 miles) on the NEDC combined cycle with the 350 bar hydrogen tank (3.7 kg of H2). The plan is to use a 700 bar tank at a later date, which would ensure a range of more than 500 km (311 miles).
The ZEV H2 weighs 1,850 kg (4,079 lbs), compared to the 1,550 kg of the Scénic 1.9 dCi.
The fuel cell hybrid vehicle has five main operating modes:
The battery alone supplies power directly to the electric motor. This power supply mode operates when the vehicles starts, when parking, or when driving in the city. It also kicks in when the car accelerates sharply, as the battery can deliver bursts of high power to complement the fuel stack.
The fuel stack alone supplies power to the electric motor. The vehicle generally uses this mode when travelling at a steady speed, e.g. on a motorway. Power not used by the electric motor is directed to the battery.
The stack and the battery deliver power to the electric motor when the vehicle’s requires an extra power boost, e.g. up a long gradient or when overtaking at speed.
When the vehicle is at a standstill with its engine running, the electricity produced by the stack is used to recharge the battery.
When the vehicle is decelerating, the electric motor feeds the power battery, acting as a generator. The fuel stack can also recharge the battery.
The new NOx trap. The new NOx Trap with catalytic converter has a dual function:
The traditional function of oxidizing hydrocarbons (produced by partial combustion) and carbon monoxide (produced by partial combustion due to a lack of oxygen);
The treatment of NOx (produced by the combustion of diesel fuel at high temperatures).
|Aftertreatment system with new NOx trap. Click to enlarge.|
The NOx Trap operates by capturing and storing NOx (for 10 minutes/10 km) then releasing it in a five-second process. During the capture phase, NOx in the exhaust is trapped on a porous carrier in the catalytic converter which is impregnated with platinum, barium, and rhodium.
The platinum converts nitrogen oxide into nitrogen dioxide (NO2). The barium, which oxidizes into barium oxide, traps and holds NO2 as part of an aqueous barium nitrate solution—Ba(NO3)2.
In the release phase a process known as reductive elimination purges the NOx Trap of the stored NOx, with the engine operating in rich-burn mode. The nitrogen oxides are converted into neutral gases, mainly nitrogen. In this way the NOx trap is regenerated.
To ensure the NOx trap operates smoothly, additional (oxygen and heat) sensors are positioned at the intake manifold and on the tailpipe. The data they capture is transmitted over the controller area network to the ECU for managing the trap.
The new aftertreatment system will be available from September 2008 in France and Germany in private fleets of 2.0 dCi Renault Espaces. Renault has filed 36 patents for its NOx Trap.