Leakage Diagnosis Method And Robustness Analysis Of Closed Refrigerant Pipe Network System

Leakage may bring danger to stable operation of refrigerant pipe networks of centralized heating system for electronic devices.Traditional leakage diagnosis method is low-effective and high labor intensity,couldn’t meet the practical requirements of fast and timely in modern devices system.With the complement of monitoring and data collection system in modern pipe networks,developing research on model-based leakage diagnosis method has a great significance for online leakage diagnosis.This paper proposes a method of using pressure sensitivity analysis for leakage diagnosis of a closed refrigerant pipe networks.A case of a refrigerant pipe networks is studied,the pipe network hydraulic model is established,and the model is calibrated by the actual hydraulic data.This model is used to calculate residuals and sensitivity matrix,and integrality correlation coefficient method to carry out leakage diagnosis.The result shows that the method can effectively diagnosis the area of leakage.In addition,two index of model accuracy index(improved Grey Relational Analysis method IGR2)and leakage diagnosis method assessment index(Fault diagnosis success percent FDSP)is proposed This two indexes is used to analysis robustness of the leakage diagnosis method in a quantitive way.First of all,the method of sensitive on leakage magnitude is studied,Then,the influence on method effectiveness and robustness of four factors which is model accuracy,measurement error,nominal leakage and pressure sensor placement is studied one by one.What’s more,coupling influence by leakage magnitude and measurement error is studied,and influence on method robustness of different factor is compared.The result shows that the diagnosis would be robust if model accuracy,measurement error and pressure sensor placement meet a certain requirement,the degree of their influence from high to low is,model accuracy,measurement error,pressure sensor placement.