Eaton Vehicle Group’s new eVaptive electronically controlled fuel tank vapor-venting system offers engineers flexibility never before possible in designing fuel systems. Designing a vehicle’s fuel and vapor-venting system is no easy task, despite the fact that much of the technology involved is not overly complex.
But in today’s automotive industry, where new vehicles are introduced at an increasingly fast pace, designing new fuel and venting systems can lead to added costs, time, and complexity. Eaton says adding in the varying and evolving emission standards across the world and eVaptive’s ability to be applied to any number of vehicle platforms illustrate its advantage over competitive systems.
Current in-tank fuel systems are largely composed of commodity parts. The technology used in eVaptive seeks to replace those antiquated systems and componentry with software-controlled actuators not presently found in automotive fuel tanks.
In a traditional fuel tank design, optimal vapor-venting positions are determined at the top of the tank where vapors accumulate. Unlike traditional vents, eVaptive system vent points can be opened and closed as needed for optimized venting via an actuator system. Any liquid fuel that enters the vents is routed to a central liquid trap where it is drained back into the fuel tank. Once the vapor and errant fuel are separated in the liquid trap, the vapor is routed to a charcoal canister for adsorption.
The controlled venting enabled by eVaptive can also assist highly boosted engines, as the natural vacuum used to purge the charcoal canister, present in a traditional internal combustion engine, may no longer be available.
eVaptive’s software can be optimized for all driving situations, as well as stationary and refueling modes, and its hardware is a “one-size-fits-all” unit that can be programmed to fit any vehicle platform.
Other benefits of the eVaptive system include:
• Reduces complexity and cost by allowing customers to use one set of hardware across all vehicle lines and tank variants;
• Prevents liquid from leaving the tank in all conditions while still venting vapors;
• Reduces validation cycles and development time;
• Maintains overall lower tank pressures in dynamic situations and at high-fuel levels;
• eVaptive system is not impacted by the shut-off height of mechanical valves;
• Enhanced On-Board Diagnostics II (OBDII) enables leak detection to ensure no hydrocarbons are escaping into the atmosphere and allows for a greater detail system check, all the way down to separate sub-systems;
• System can replace current FTIV (Fuel Tank Isolation Valve) that is used to plug the fuel tank on hybrid vehicles when the electric motor is operating, thereby reducing cost and complexity; and,
• eVaptive system can optimize the depressurization of the fuel tank that is required just prior to a refueling event on plug-in hybrid electric vehicle applications.
eVaptive has been presented at multiple industry conferences in the US, Germany, and China, and has garnered interest and feedback from multiple global OEMs and fuel tank suppliers. Now that the system has been demonstrated, efforts are underway to design a production version and determine possible value pricing configurations.
“This new technology is an example of Eaton’s advanced engineering capabilities as it looks to provide customers with solutions that not only provide a single packaging option but also the flexibility to customize the system based on the specific vehicle design,” said Deborah Kullman, vice president, general manager, chassis driveline and controls, Eaton Vehicle Group. “As the industry moves from traditional mechanical to electronic solutions, Eaton is leading the way with technologies such as eVaptive.”