Research On Hydraulic Actuator Performance Of Capacity Regulating System Used In Reciprocating Compressors

As wildly used machine in chemical industry, the function of compressors is to transform the motor power into gas energy, achieving the purpose of gas compression or delivery. Because of the inconsistency between reciprocating compressor displacement and air needed, the compressor capacity regulation arises at the historic moment. The method of depressing off suction valves in partial stroke is wildly used in reciprocating compressors for its full range and stepless characteristics. This method adopts hydraulic actuator to depress off suction valves before compression stroke, so the gas flows back into the air and the energy is saved. So the effect of capacity regulation depends largely on the precision and stability of hydraulic system.Based on the National Key Technology R&D Program "Key Technology Development Program for High Efficiency Compressor", the article focused on the performance of hydraulic actuator with thoroughly theoretical and experimental study. Firstly, the structures and size of hydraulic components are calculated. Secondly, the physical model of hydraulic distributor is established, the meshing and parameters setting are done. Through simulation, article gives the velocity distribution and pressure distribution in hydraulic distributor, and puts forward reasonable improvement methods for the problems existing. Lastly, the hydraulic actuator’s operating effects are evaluated with simulation and experiment methods.The main content of the article is summarized as follows:The first part is hydraulic actuator design. According to the movement demand of hydraulic actuator, article completes the calculation and type selection of hydraulic pump, drive motor, oil tank, relief valve, pipes, hydraulic distributor, hydraulic cylinder, etc. Data acquisition and monitoring system based on LabVIEW is designed. The system can implement the function of valve working condition monitoring, oil pressure monitoring and piston movement monitoring.The second part is flow field characteristics research and structure improvement of hydraulic distributor. The simulation of oil flow characteristics in hydraulic distributor is carried out. Paper gives the simulation results of velocity distribution, pressure distribution and path lines in the inner flow channels of hydraulic distributor. Improvement program is given according to the simulation results.The third part is dynamic performance research of hydraulic actuator. The system model of hydraulic actuator is set up using software AMESim, and the model is used to observe the influences of parameters change on hydraulic actuator performance. Finally, the simulation results are validated by experiment results, which are proved to be effective ways for this research.