Performance monitoring of gas turbine components: a real case study using a micro gas turbine test rig

Estimating the performance of all the components of a recuperated micro gas turbine cycle plays a determinant role in improving their reliability for distributed power generation and cogeneration. The monitoring and diagnostic activity consists in continuously evaluating the productivity capacity and the efficiency of the plant, using the stream of data coming from the plant’s instrumentation. In this framework a diagnostic tool for the micro gas turbine installed at the TPG test rig (located in Savona, Italy) was developed, with the objective of monitoring the operating parameters of the turbomachine, the performance of the heat exchanger and, in general, the good operation of the plant. Even though the commercial machine is equipped with the essential probes for control (rotational speed, TOT, intake temperature and eating water temperature meters) and diagnostic purposes (vibration sensor, filter differential pressure and other thermocouples), further instruments were introduced in the test rig to measure a larger number of properties and points. As result of this, a wide number of measurements is available and can be effectively used for the development of a diagnostic model. The diagnostic model presented in this paper is written in Matlab-Simulink® environment and, in its first version, provides information about compressor and turbine efficiency and heat exchanger effectiveness. The model was developed starting from the turbomachinery maps and the heat exchanger design performance. A validation of the code was performed using the measurements coming directly from the data acquisition system. Preliminary results coming from the model are presented, showing the different performance of each component of the plant in the various operating conditions.