The Research On Monitoring And Diagnosing For Stirling Engine

Stirling engine is a closed-cycle reciprocating engine by the means of external heating gas compression and expansion cyclical in different temperature, with the features of high efficiency, low noise and low pollution. With the development of Stirling engine, the existing technology and management measures have been unable to meet the demands of daily management. In order to improve the reliability level of Stirling engine, timely warn to early failures, and reduce the breakdowns and parking, it's very importment to research for Stirling engine on fault diagnosis.In this paper, on the basis of investigation in Stirling engine, refer to ongoing monitoring and diagnosis of advanced methods about reciprocating machinery, the Monitoring and Diagnosing System for Stirling Engine is developed. The major contents of the paper are as follows:1. The methods of instantaneous speed signal measurement about Stirling engine are introduced in detail. The way of digital filtering, the whole cycle average and the average of teeth is used to remove the noise component of the instantaneous speed waveform. The instantaneous speed signal is analysised in time-frequency domain; the characteristic parameters are extracted for fault diagnosis. According to the structure of the Stirling Engine, a dynamic model is improved for the simulation analysis. The calculated result is compared with the measured waveforms.2. The expert system based on the fault tree is used in the development of the Monitoring and Diagnosing System for Stirling Engine; expert system structure is designed; as a knowledge base platform, SQL Server2000 is choiced to manage the knowledge base. The mothod of knowledge representation, the data-driven forward chaining strategy and knowledge base are introduced in detail.3. The Monitoring and Diagnosing System for Stirling Engine is developed. The methods of thermal parameters and instantaneous speed monitoring are applied in the system. The expert system is used for fault diagnosis. The function of monitoring, diagnosing, knowledge base maintenance, data management and report generation can be best achieved. The research work about Stirling engine in this paper is significant for maintenance management on Stirling engine. The Monitoring and Diagnosing System for Stirling Engine can improve the level of day-to-day management.