Study On Fault Diagnosis Technology About Chilly Water Set Of Single Screw

The probability and the reason of the fault of HVAC are increasing with the big and complex building,so it is difficult to meet the need of fault detection only depending on the manual method and it is urgent to study the fault detection of HVAC.This dissertation adopts the combined method including theory analysis and experiment validation to study the fault detection of chilly water set of single screw. Firstly, the dissertation analyzes the principle of refrigeration circulation of steam compression, analyzes the performance characteristic of refrigerator and gets the fault characteristics of chilly water set in theory.Nine faults including decreasing flux of cooling water and non-condense gas in set etc are simulated in the experiment part of the dissertation. Keep other factors constantly while simulate certain fault and keep simulated condition and real condition similar.Dispose the experiment data and select five internal parameters as the parameters of fault detection including evaporating temperature, condensing temperature etc from all the variables. Variation rule of one of the five parameters represents the one running state. So the five rules of fault detection form one rule of fault detection. Comparing the rule and the theory analysis, the comparison result is ok.According to the detection rule of the simulation faults,diagnostic rules for those faults simulated in this thesis are obtained.The software is developed based on the rule of fault detection that can be used to detect the running state conveniently.