Fault Detection and Diagnostics for Rooftop Air Conditioners

5
LIST OF FIGURES
Figure E-1. FDD demonstration output ........................................................................... 13
Figure E-2 Histogram of the normalized fault indicator for low refrigerant charge ........ 14
Figure E-3 Histogram of the cooling capacity degradation.............................................. 14
Figure E-4 Histogram of the EER degradation................................................................. 15
Figure 1-1 Paper statistics in HVAC FDD with time ....................................................... 23
Figure 1-2 Paper statistics in HVAC FDD with system ................................................... 23
Figure 1-3 Supervision approach of HVAC&R equipment.............................................. 25
Figure 3-1 Interactions of Rooftop Unit System............................................................... 40
Figure 3-2 Structure of the SRB FDD method ................................................................. 42
Figure 3-3 Fault detection classifier scheme for a 2-dimensional case ............................ 45
Figure 3-4 Fault detection and diagnosis boundaries ....................................................... 46
Figure 3-5 Distance method for fault diagnosis................................................................ 47
Figure 4-1 Taxonomy of Rooftop Faults .......................................................................... 51
Figure 4-2 Decoupling Scheme of Rooftop System Faults .............................................. 52
Figure 4-3 Decoupling compressor valve leakage fault using estimated compressor power
measurement and estimated refrigerant mass flow rate............................................ 55
Figure 4-4 Decoupling condenser fouling fault using measured refrigerant mass flow rate
................................................................................................................................... 56
Figure 4-5 Decoupling condenser fouling fault using estimated refrigerant mass flow rate
................................................................................................................................... 57
Figure 4-6 Decoupling evaporator fouling fault using measured evaporator air mass flow
rate............................................................................................................................. 58
Figure 4-7 Decoupling evaporator fouling using measured refrigerant mass flow rate ... 59
Figure 4-8 Decoupling evaporator fouling using estimated refrigerant mass flow rate ... 59
Figure 4-9 Decoupling liquid-line restriction using measured pressure drop................... 60
Figure 4-10 Decoupling liquid-line restriction using estimated pressure P
up
and measured
P
3
.............................................................................................................................. 61
Figure 4-11 Decoupling liquid-line restriction using estimated pressure drop................. 61
Figure 4-12 Decoupling refrigerant leakage faults using ∆ Tsh
− sc
..................................... 62
Figure 4-13 Illustration of Demo Movie........................................................................... 63
Figure 4-14 Timeline of the fault simulation in minutes. ................................................. 64
Figure 4-15 Outputs of the FDD demonstration after introduction of low refrigerant
charge fault................................................................................................................ 68
Figure 4-16 Outputs of the FDD demonstration after introduction of condenser fouling
fault ........................................................................................................................... 69