Pneumatically assisted Truck – CAP

The air hybrid engine absorbs the vehicle kinetic energy during braking, stores it in an air tank in the form of compressed air, and reuses it to propel a vehicle during cruising and acceleration. Capturing, storing and reusing this braking energy to give additional power can therefore improve fuel economy to a range of 4% - 18%.
The idea is not new, many previous investigations propose to work on a VVA or HVA engine to make use of the flexibility of such systems in controlling the air flow. Another category of investigations brings adapted engine designs with compressed air dedicated valve added to the engine cylinder head.
The technology might be more successfully used in hybridizations and auxiliary power devices, just as electric hybrids. The main differences between energy storage in batteries and in compressed air is that compressed air tanks are cheaper, environmentally-friendlier, easily disposable, have a much higher life cycle and do not drain in time, if a proper sealing is guaranteed. They can also benefit from the high temperature exhaust from the internal combustion engine in hybrids, and can generate high transient torques, as opposed to limitations of high-current demands in batteries. This is also important in regenerative braking, where a great amount of kinetic energy must be almost instantaneously absorbed. The disadvantages are the greater complexity and size of the engine and auxiliary systems (such as heating fluid, etc).
This project aims at the conception and evaluation of the pneumatic hybrid functionality with minor modifications on the engine itself. The target application is a long haul truck (4O tonnes). For this kind of application the standard electric hybrid system is too expensive and the recoverd energy is too low, mainly because of the few stop and start phases.