The performance of a power pack for a compressed air driven vehicle

Compressed air driven vehicles have two advantages over their rival electro-chemical battery driven vehicles in the locally non-polluting transport market, namely the much shorter recharging time possible and the long life of the high-pressure storage vessels. Comparatively poor energy density and poor efficiency of the initial air compression process have made these systems unattractive to the transport sector. Lightweight carbon fibre compressed air storage vessels are now practical but, if compressed air driven vehicles are to compete successfully further weight and efficiency savings must be made. A possible source of energy is the ambient heat available from the air in the vehicles immediate environment. This would require a lightweight high efficiency heat exchanger to be placed in the airflow between the pressure vessel and the air motor. A heat pipe based heat exchanger, capable of fulfilling these demands, has been built and tested in various configurations and is now described. The unit is capable of significantly increasing the energy, delivered to the air motor, at minimal cost.