Energy loss mechanisms and multi-cylinder coordinated fault-tolerant control in compressor capacity control systems

Capacity control actuators in reciprocating compressors are prone to faults, while traditional fault-tolerant control methods mainly rely on local compensation strategies, making it difficult to simultaneously maintain overall compressor performance and load balance. To address this issue, a multi-compression-chamber coordinated fault-tolerant control method based on discharge mass flow redistribution is proposed. By isolating faulty actuators and coordinating the remaining healthy actuators, cooperative redistribution of discharge mass flow is achieved while simultaneously considering energy consumption, operational performance, and load balancing. A high-fidelity three-dimensional (3D) flow field model is established, incorporating complex flow channel structures, independent valve motions, and coupled parallel flow characteristics. Furthermore, the thermodynamic characteristics and energy loss evolution under four typical fault conditions are analyzed to provide support for fault diagnosis and discharge mass flow redistribution. Experimental results show that, while restoring the total discharge mass flow, the proposed method can significantly improve the overall operating state of the compressor, with recovery rates of multiple energy-consumption- and performance-related indicators reaching 40–95%.