Air Handling Unit Fault Detection And Diagnosis Method Research On Variable Air Volume (VAW) Air Conditioning System

The energy crisis has become a worldwide problem of common concern, in orderto solve this problem, people are working to find all sorts of new energy andenergy-saving technology. Building energy consumption is large proportion of totalenergy consumption in society, and the air conditioning system of building energyconsumption energy consumption is the main component, so the energy-saving of airconditioning system has great potential. The variable air volume (VAV)air-conditioning system has characteristic of energy-saving and good thermal comfort,In the HVAC area, the variable air volume (VAV) air-conditioning system soon got arapid development and widely application. However, due to the composition of thevariable air volume (VAV) air conditioning system is complex, the fault there is more,too. These faults will make the air-conditioning system not in the optimal operationstate, cause the consequences of indoor environment degradation and high energyconsumption, etc. So the research for VAV system fault detection and diagnosis has avital significance.VAV system has great energy saving potential, air handling units (AHU) is animportant part of the variable air volume system, so many scholars and experts do athorough research work. At present, some researchers mainly adopts pure expert rulesfor the research of air handling units fault detection and diagnosis.Based on the analysis of VAV system air handling units work and controlprinciple, Combined with practical engineering projects in Hong Kong, this papermakes a research on a online fault detection and diagnosis method of air handlingunits of the VAV system. The CUSUM Chart method is applied to online faultdetection of VAV system air handling units, combining malfunction happenedduration, greatly reduce the misstatement fault rate. Summarizes the fault diagnosisrules put forward by related scholars and experts, and combining with the actualsituation, put forward some new fault diagnosis rules, finally establishes a perfectfault diagnosis expert rules set and designs the fault isolation fault diagnosis method,develops an air handling units online fault detection and diagnosis software of theVAV system by these diagnosis rules. The fault detection and diagnosis software hasbeen developed successfully in Cambridge House in Hong Kong on the onlineapplication and validation. Through the online validation of the air handling units fault detection anddiagnosis software of the VAV system, this software can well diagnose correspondingfaults, make air handling units run in the best mode, meet the air conditioning areacomfort requirements, but also can achieve the purpose of saving energy.