No abstract

Exhausted air reuse is one of the most important energy-saving methods for pneumatic actuation systems. However, traditional exhausted air storage tanks have the disadvantages of unstable pressure and low energy density. To solve these problems, this paper presents an energy-saving method by exhausted air reuse for industrial pneumatic actuation systems based on a constant pressure elastic accumulator. Employing the hyperelastic mechanical properties of rubber, a constant pressure energy storage accumulator is designed and applied to a pneumatic circuit for exhausted air recovery and energy saving. In the circuit, the accumulator recovers exhausted air from a primary cylinder and supplies it to another secondary cylinder. Then the secondary cylinder no longer needs air supply from the air compressor to achieve the purpose of energy saving. The energy-saving mathematical model of the circuit is established using air consumption, and the system operation test bed is built to verify the energy-saving efficiency. Results show that the maximum energy-saving efficiency of the system is 54.1% under given working conditions, and the stability of the cylinder can be improved.

Focusing on the low energy-storage efficiency and unstable energy output of existing accumulators, this paper proposes a novel constant-pressure elastic-strain energy accumulator based on the rubber material hyperelastic effect. The proposed accumulator can store and release energy at a constant pressure. Based on the exergy analysis method, the charging/discharging energy storage efficiency of a constant-pressure elastic-strain energy accumulator was analyzed. Then, the Mullins effect on the rubber airbag over multiple charging/discharging cycles was studied. Finally, a test platform was established to verify the energy storage efficiency, as well as the expansion and contraction pressure stability of the rubber accumulator during charging/discharging cycles. The experimental results showed that the energy storage efficiency calculation by the exergy analysis method was more accurate compared with the enthalpy analysis method. In tests with more than 200 cycles, the rubber airbag energy storage efficiency was always higher than 76%, and the expansion and contraction pressure errors at a steady state were less than 2.92 and 1.79 kPa, respectively. The results showed that the rubber airbag could be used as an effective energy storage component, which is very meaningful for energy recovery in pneumatic or hydraulic systems.