Development And Research On Exhausted-air Reclaiming Control System

The applications of pneumatic actuators have been extending widely in many fields as the most important executive elements. However, after the pneumatic actuator finished a stroke, the air with certain pressure in the original working chamber is exhausted directly into the atmosphere, and the exhausted-air has the capacity for work yet. If some of the air can be reclaimed for reutilization, which has momentous energy-saving meaning for the whole industry system. However, the pressure in the air tank will increase gradually after several working cycles if reclaiming the discharging chamber's pressure-air with an air tank directly, which will cause bad influence on the piston's movement characteristic. Aiming at these problems, a new technical scheme has been studied in this thesis which can not only reclaim more pressure-air of the discharging chamber, but also influence less on the piston's movement characteristics, and the in-depth theoretical analysis and experimental study have been done on concerning key technical problems.An original exhausted-air reclaiming technical method has been presented, that is to say, the discharging chamber's pressure-air is reclaimed into the air tank through the additory of the exhausted-air reclaiming control devices which can be considered as the mid-pressure air supply for reutilization in order to realize the aim to save energy. First, a constitution form of the reclaim system which is efficient and fit for the industrial application has been studied, and then the corresponding mathematical model of the system has been built up, and the key control technique problem has been analyzed by simulation and experiments. This established the theoretical foundation for the in-depth study of the exhausted-air reclaiming control criterion and the evaluation method of the exhausted-air reclaiming efficiency.The exhausted-air reclaim control criterion and control strategy have been given in this thesis in order to present the critical control criterion to control the switch of the exhausted-air reclaiming process. First, the theoretical expression of exhaust-air reclaiming control differential pressure has been deducted on the basis of the theoretical analysis of the exhaust-air reclaiming control process, and the analysis indicates that the control differential pressure is relative to the supply pressure, etc, and the approximate...