The Dynamics Analysis Of The Reciprocating Compressor With The Capacity Regulation System

The stepless capacity regulation method by depressing the suction valve makes the inhalational intake gas back to suction chamber during partial compression stroke, only the required gas is compressed. With this method, compressor capacity can be regulated steplessly and the power consumption is saved proportionally with capacity. However, after this system is used in reciprocating compressor system, there are some failures appeared, such as the lower capacity than the expected value, the piston ring wear, the abnormal sound in the compressor and so on. So the promotion of this system has been limited in the industry. Therefore, it is necessary to analyze the mechanical effects of reciprocating compressor in stepless capacity regulation situation, and to remove all the trouble they cause. Then the stepless capacity regulation system could be widely applied in industry.Based on the National Key Technology R&D Progect "Key Technology Development Program for High Efficiency Compressor" (No.2008BAF34B13), the thermal cycle and valve dynamic in the case of stepless capacity regulation are deeply studied by theory and experiment in this paper. The experiment equipment which can regulate the capacity from 0-100% is established. Some failures caused by the abnormal hydraulic system will be analyzed and solved by experiment measurement and computer simulation method.The main research topics in this paper are as follows: 1. A theoretical thermal cycle model in case of stepless capacity regulation has been developed. Capacity variation with regard to the unloaded crank angle has been calculated. The calculation results are in accordance with experiments.2. The laboratory stepless capacity control system and associated signal test systems and control systems for stepless capacity control system has been established. These systems will provide experimental evidence for the operation status monitoring and failure analysis. 3. Through establishing the mechanical motion modal of the compressor and computer simulation, the changes of mechanical properties have been analyzed and cause analysis and prevention of the faults are proposed.4. Through experiment measurement and theory analysis, the corresponding solution of common faults of the hydraulic system in the stepless capacity control system has been analyzed; some guidance and advices have been provided for the piping arrangement and the selection of hydraulic oil station of hydraulic system.