Citation: Du, H.; Liu, W.; Bian, X.;
Xiong, W. Energy-Saving for
Industrial Pneumatic Actuation
Systems by Exhausted Air Reuse
Based on a Constant Pressure Elastic
Accumulator. Sustainability 2022, 14,
3535. https://doi.org/10.3390/
su14063535
Academic Editors: João Carlos de
Oliveira Matias and Paolo Renna
Received: 12 February 2022
Accepted: 16 March 2022
Published: 17 March 2022
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Article
Energy-Saving for Industrial Pneumatic Actuation Systems
by Exhausted Air Reuse Based on a Constant Pressure
Elastic Accumulator
Hongwang Du *, Wei Liu, Xin Bian and Wei Xiong
Ship Electromechanical Equipment Institute, Dalian Maritime University, Dalian 116026, China;
liuwei@dlmu.edu.cn (W.L.); bianxin@dlmu.edu.cn (X.B.); xiongwei@dlmu.edu.cn (W.X.)
* Correspondence: duhw_1984@dlmu.edu.cn
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.
Keywords:
pneumatic energy-saving; exhausted air reuse; constant pressure energy storage; elastic
strain accumulator; energy efficiency
1. Introduction
As one of the widely used energy sources in industrial fields, compressed air is
widely used in all walks of life because of its high speed, cleanliness, safety, low cost, and
easy maintenance. However, due to the shortcomings of leakage and compressibility of
air, th
e co
mpressed air utilization rate is quite inefficient. Many scholars have studied
compressed air energy saving.
Exhausted air reuse is one of the most effective ways to save energy in pneumatic
systems, which can save about 50% of compressed air consumption at most, and it is easy
to operate [
1
]. Yang et al. used a bypass valve to connect the cylinder inlet and exhaust
chamber and delivered part of the compressed air in the cylinder exhaust chamber to the
inlet chamber for reuse. This method saved about 12–28% energy. Due to the presence
of the bypass valve, cylinder drive performance was also improved [
2
]. Seslija et al. put
forward a new type of control mode using a bypass valve together with a PWM control,
showing that 30% of energy was saved under the same working conditions in comparison
to the traditional PWM control system. However, the tracking performance of the PWM
bypass control system was slightly worse because it took more time to reach the required
position influenced by gravity and load [
3
]. Du et al. connected the cylinder inlet and
exhaust chamber using an air compressor [
4
]. By directly controlling the piston rod speed
with a motor, 74% compressed air was saved on the premise of ensuring the smooth
operation of the piston. However, the applicability and robustness of this method needed
to be further verified [
5
]. Li et al. collected the compressed air from the exhaust chamber
Sustainability 2022, 14, 3535. https://doi.org/10.3390/su14063535 https://www.mdpi.com/journal/sustainability
