원전 비상디젤발전기 연료분사펌프 진단신호 분석

Abstract

This study analyzes the characteristics of combustion and fuel injection components through the signals generated during engine operation. This information is used to reliably diagnose the engine conditions of emergency diesel generators at nuclear power plants. The characteristics of the combustion signal were analyzed using a medium-speed four-stroke diesel engine under different loads. The same fuel injection pump as that used during the engine operating conditions was installed in a fuel injection pump simulator. Further, the signal characteristics were analyzed according to the operation load and measurement points. This study confirmed that the injection signal of the fuel injection pump was divided into two signals (i.e., fuel injection start and end phase) according to an increase in the operation load. In a medium-speed diesel generator, it is possible to detect a reliable fuel injection end signal downstream of the fuel injection pump delivery valve. The phase difference at the beginning of combustion according to the operating load is ineffective for diagnosing the combustion conditions. The phase difference boundary of the injection signals is the delivery valve at the upper end of the fuel injection pump. The fuel injection phase estimated using the combustion pressure coincides with the phase of the diagnostic signal acquired downstream of the delivery valve.