MODEL BASED FAULT DETECTION AND DIAGNOSIS METHODOLOGY FOR HVAC SUBSYSTEMS

摘要

A fault detection system for an HVAC system including sensors for measuring the performance of a condenser, a compressor, an evaporator, and a chiller. The fault detection system is provided with a thermodynamic preprocessor f or calculating characteristic quantities (CQ's) from a plurality of measured inputs. Also provided is a base-case lookup table for storing plural first sets of CQ values generated by the thermodynamic preprocessor in an initial period in which fault-free operation of the HVAC system is assumed, a first set of CQ values being generated for each of plural different measured input values. An interpolator is provided for interpolating a set of base-case CQ values from the first sets of CQ values stored in the base-case lookup table for a given set of measured inputs. A fault- detector detects a fault when a difference between actual CQ values and base-case CQ values exceeds a predetermined threshold value for at least one of the CQ values. A fault classifier classifies a detected fault based on which ones of the actual CQ values exce ed the interpolated CQ values.