Experimental study of flow energy merger of hybrid pneumatic power system

Hybrid pneumatic power system (HPPS) is an energy system, which stores flow work instead of battery’s electric-chemical energy. Moreover, this system can recycle the exhaust-gas energy and make the internal combustion engine (ICE) operates at its optimal point. Thus, it can be considered as an effective solution to improve the system’s thermal efficiency and significantly reduce the exhaust emissions. In this paper, an experimental study on the flow work storing and flow energy merger in the HPPS is presented. Experimental results showed that the storing capability of the flow energy, exhaust-gas energy recycling and merger flow energy are strongly dependent on the operating pressure (P
air
) in the system and contraction of cross-section area (CSA). Under the optimal adjustment of the CSA for the change in the P
air
, the exhaust-gas energy recycling efficiency reached about 75–80%; therefore, the system’s energy efficiency will achieve about 45%.