涡轴发动机性能差异故障分析

Fault Analysis of Performance Difference for a Turbo-Shaft Engine

某涡轴发动机在更换热电偶后进行整机试验过程中出现了性能差异。通过故障树分析了产生该性能差异的原因，定位为热电偶偶丝性能退化及探针头部微裂纹导致绝缘电阻降低，进而引起测量的燃气温度偏低。采取严格筛选偶丝质量、改进探针头部结构和工艺的措施，发动机长试验证该措施有效。

The performance of a turbo-shaft engine differed from itself after changing the thermal couple during the test. In this paper, a fault tree was constructed to analyze the reason of this performance difference. The fault reasons were that the wire performance of the thermal couple declined and the head of the probe was slightly cracked, which resulted in less insulation and lower measuring temperature. Actions are that the quality of the thermal couple wire will be strictly screened and the structure and process of the probe will be im- proved. These actions are effective after long-time test on the engine.