Development Of Full-Range Capacity Stepless Control System In Reciprocating Compressor

Reciprocating compressors have widely applied in the petrochemical industries which are the national economy's pillar industries. With the constant changing in petrochemical processes and the growing tensions energy in the world, the capacity regulation is needed, moreover the reducing energy is needed based on the capacity decreased ratio. Full-range capacity stepless control is one of the methods of capacity regulating for reciprocating compressor, and it possesses economic, safe and well-fixing character.From the reciprocating compressors cycle with the actual work, the basic principle of full-range capacity stepless control is analysed. The mathematical models of thermodynamic calculations of full-range capacity stepless control is established. The mathematical relations between state parameters of multi-level compressors and times of pressing-off inlet valve are calculated.The entire system, which achieves synchronous operation function between reciprocating compressor and hydraulic distributor and regulatory function of capecity and Level-pressure, is composed of the actuating mechanism and the monitoring system. Hydraulic distributor is the core of the actuating mechanism. The monitoring system is composed of host computer and slave computer. Servo-motor and controller make up slave computer. PC and configuration software make up host computer.Stepless control system is established in the lab and applied to a 3L10/8 L-type air compressors. Synchronous operation between hydraulic distributor and reciprocating compressor and regulation control of capacity, level-pressure and exhaust temperature are initially achieveed. The changeing time of pressing-off inlet valve, capacity, level-pressure and exhaust temperature in various status are analysed and compared with theoretical calculations based on lab experiment results. The conclution is found.Research work is conclused and the future study is presented.