Experimental Research on Performance Comparison of Compressed Air Engine under Different Operation Modes

An air-powered vehicle is a low-cost method to achieve low-pollution transportation, and compressed air engines (CAE) have become a research hotspot for their compact structure, low consumption, and wide working conditions. In this study, a pneumatic motor (PM) test bench is built and tested under different inlet pressures, operation modes, and three driving cycles. On the basis of the data obtained by sensors, power output, compressed air consumption rate, and efficiency are calculated to evaluate the pneumatic motor performances. The results show that with an increase in rotation speed, the output power and efficiency first increase and then decrease, and the compression air consumption rate decreases. With an increase in torque, the rotation speed decreases, and the power output and efficiency first increase and then decrease. With an increase in mass flow rate, the torque increases, the power output and efficiency first increase and then decrease. The pneumatic motor achieves the best performance under a rotation speed of 800-1200 rpm, where power output, efficiency, and compressed air consumption rates are 1498 W, 13.6%, and 10 J/g, respectively. The pneumatic motor achieves the best power output and efficiency under the UDDS driving cycle.