No abstract

Current researches on the development of gas turbine related power plants such as HAT cycle and Combined Cycle are aimed to increase the plant efficiency and output power, while reducing the cost of power generation and emission. Humid air turbine cycle (HAT) is one of innovative cycles, which are able to provide a substantial power boost of the system and an efficiency rise of several percentage points. In order to perform energy analysis of Full Flow HAT cycle and Part Flow HAT cycle an advanced thermodynamic model is developed, which is enabling evaluation of behavior of Full Flow and Part Flow Humid Air Turbines and predicting the influence of operational parameters in the performance of these cycles. Changes in level of cooling technology are introduced in the model. Results show that this parameter has great influence on the cycle efficiency, especially at high Turbine Inlet Temperature (TIT). Also to model the accurate behavior of humid air, a new thermodynamic model is used to predict thermodynamic properties of air-water mixture at elevated temperature and pressure. In The pressure, in which compressor divided into two sections (LP/HP) is considered to find the optimum performance of cycle. Finally performance of Part Flow HAT cycle at different operating conditions (compressor pressure ratio, TIT) and bypass factors is verified and compared with Full Flow HAT cycle. Results show that in Part Flow HAT cycle changes in bypass factor has little influence on performance of the cycle. Furthermore, Part Flow HAT cycle exhibits better performance (compared to Full Flow HAT cycle) at high pressure ratio region, and vice versa at low pressure ratio region.

Performance testing of gas turbine packages is becoming increasingly common to assure that the turbine output power and efficiency meet the expected values during the turbine life cycle. In the conventional Performance Test Analysis (PTA), field measurements and calculations are carried out on the basis of standard codes to find the whole engine performance parameters (i.e. power and efficiency) at test conditions and to compare them with the expected values. Recently, regarding the development of Gas Path Analysis (GPA) and diagnostic techniques to investigate the gas turbine health state, performance test capabilities can be improved by using these analyses to perform further examination on the measured test data and to determine the deviation of gas turbine component health parameters from the “new and clean” health state during the engine operation. Determining the mentioned deviations, potentials of engine improvement in the component level can be obtained and subsequently the action-oriented recommendations are reported as guidelines in the overhaul. Also in the case of performance test after the overhaul, the main result of the GPA application in PTA is the verification of the overhaul effectiveness. Using the GPA in the cases studied in this paper indicates that heath state of engine components can be investigated from the performance test data and as the main result, it is show that applying the GPA, it is possible to distinguish the effect of non-recoverable degradation and that of the poor overhaul on the engine performance and finally to assess technically the effectiveness of overhaul.