Examining the impact of common faults on chiller performance through experimental investigation and parameter sensitivity analysis

Abstract

Chillers are the important components across various applications, and understanding the impact of common faults on their performance is crucial for monitoring fault progression and predicting degradation. Consequently, an experimental investigation was conducted on a magnetic levitation-driven chiller across different severity levels. The quantitative influence of common faults on performance was then analyzed, with a specific focus on thermodynamic mechanism parameters. From a data variation perspective, a sensitivity analysis was implemented to identify the fault-sensitive parameters that exhibited noteworthy variations due to faults. From a classification performance perspective, the diagnosis-effective parameters were identified based on their significance in fault diagnosis. The results of this study led to several key conclusions: 1) Trends and magnitudes of changes in 38 parameters related to nine typical faults are identified in comparison to their normal levels; 2) Common faults have a significant influence on thermodynamic mechanism parameters, causing big changes in two to eight thermodynamic mechanism parameters for each fault; 3) Discrepancies between fault-sensitive parameters and diagnosis-effective parameters results in a difference of up to 64% in diagnostic performance; 4) Nine decoupling parameters are identified as pivotal in diagnosing concurrent faults, and an effective set of fault diagnosis rules is recommended. These findings provide valuable insights into the selection of sensitive parameters, identification of fault-decoupling parameters, and the development of fully interpretable and reliable fault diagnosis approaches.