A Methodology for Diagnosing Multiple-Simultaneous Faults in Rooftop Air Conditioners

摘要

Existing methods addressing automated fault detection and diagnosis (FDD) for vapor compression air conditioning system have good performance for faults that occur individually, but they have difficulty in handling multiple -simultaneous faults. In addition, the methods require measurements over a wide range of conditions for training reference models, the development of which can be time consuming and cost-prohibitive. This paper demonstrates that decoupling is the key to handle multiple-simultaneous faults. To eliminate cost-prohibitive overall system modeling, a mathematical decoupling methodology is developed. During the mathematical development, a previously developed FDD method, termed the statistical rule-based (SRB) method, is re-examined and cast within the general mathematical framework. The method is evaluated using laboratory data and demonstrated using a field application.