子方阵分析法对发动机进行故障诊断

本文提出的子方阵分析法可在测量参数较少的情况下对部件故障进行诊断。本方法的特点是将故障参数进行组合 ,每组中故障参数数目等于监测参数数目 ,以使故障参数可对监测参数求解。本文给出了选择最可能的解的选择准则 ,数值试验证明这个方法对诊断一个部件或同时有两个部件出现故障是非常有效的 ,这正是发动机出现故障的早期情况。本文也指出了必须十分注意的问题 ,以免误诊。本方法用于 JT9D发动机显示了其有效性。

SUB-MATRICES ANALYSIS APPLIED TO ENGINE FAULTS DIAGNOSIS

The Gas Path Analysis method for fault diagnosis has be known as an effective method.But the crucial problem is the necessity of measuring a number of aerothermodynamic parameters more than or at least equal to the number of component fault parameters.But the number of measured parameters is always confined by cost and the structure integrity of the engine.The Sub-Matrices Analysis presented in this paper can perform component directed fault diagnosis with less measured parameters.The feature of this method is to combine the fault parameters into groups,in each of which the number of fault parameters equals the number of measured parameters to make the fault parameters solvable with respect to measured parameters.Thus,a set of solutions may be obtained.In order to select the most possible solution(s),the criteria are also given.The numerical investigation shows that this method is very effective to diagnose the malfunction occuring in one or two components which is the usual case at an early stage of engine fault.The problems which are worth careful consideration to avoid false diagnosis are also pointed out.Application of this method to JT9D commercial engine verifies its effectiveness.