This paper presents a comprehensive computational analysis of a real gas turbine, considering the first and second laws of thermodynamics and employing an iterative trial-and-error approach. An equilibrium constant-based combustion model capable of calculating mole fractions of 10 species and applicable to various hydrocarbon fuels has been developed. The model can predict the mole fractions and production rates of pollutants such as NOx, CO, and CO2. In addition, steam injection has been employed in this model to reduce the formation of NOx and other combustion-generated pollutants. This technique lowers the flame temperature and alters the mechanisms of pollutant formation. A comprehensive simulation model was employed in this paper to investigate the impact of steam injection and other key parameters on the performance and emissions of a combined gas cycle. Energy, exergy, economic, and environmental analyses were conducted to provide a comprehensive evaluation of the system. Finally, a modified genetic algorithm is employed to optimize a multi-objective function considering total cost rate, CO2 index, and second law efficiency. The results of the developed combustion model have been validated against CEA and GASEQ software, demonstrating a maximum average error of only 0.5027% for 10 species. As a result of the multi-objective optimization, a three-dimensional Pareto front is obtained, indicating a maximum achievable exergy efficiency of 0.4058%, a minimum total cost rate of $1471.2 per hour, and a CO2 index of 0.5075 kg/kWh. The distribution of the primary decision variables reveals the optimal range for these variables where Pareto optimal points are obtained. Based on the scatter analysis, the optimal steam injection mass flow rate was determined to be 26.9 kg/s (corresponding to 10.63% of the total air mass flow rate). This optimal value simultaneously optimizes the system's performance, economic, and environmental indicators.
Axial compressors tend to experience significantly increased losses during off-design operation and are prone to flow separation under high aerodynamic loads. Active flow control (AFC) presents a way to counteract this by means of local injection or aspiration, in order to obtain more favourable momentum distributions. It is a strength of active injection methods that the injection rates may be adapted during compressor operation, in order to maximise the benefit at different operating points. This paper investigates the potential of varying the mass-flow rate of a suction-side stator injection, in order to improve the off-design performance.
The impingement cooling of hydrocarbon fuels represented by kerosene has broad application prospects in the field of hypersonic aircraft and engine thermal protection. However, compared with air and water, the thermal properties of kerosene are more complex and need to be further studied. Using the Reynolds average method and the SST k-ω turbulence model, the superalloy is used as the heat transfer material. By simplifying the model, the effects of different jet structures on the impingement cooling effect under the same inlet conditions are numerically simulated. The wall temperature distribution is used as the evaluation index of heat transfer performance, and the overall design of the stabilizer is based on this. The research shows that the wall temperature of the stabilizer shows a tendency of increasing annularly around the stagnation point. The increase of opening ratio, hole pitch and jet distance will lead to the decrease of heat transfer effect.
The emergency gas turbine generators offered by IHI Power Systems are designed to supply large volumes of electric power instantaneously in the event of power outages. They are installed in data centers, public facilities, waterworks systems, and other facilities, where they play key roles in ensuring the safety and security of people and society. To meet the growing need for highcapacity generators, we have undertaken component development for higher output compressors and turbine blades to boost the output of 2 MW class gas turbine engines by 25%. This paper describes the efforts to develop compressors and turbines required for highpowered emergency gas turbine.
A full 3D rotor/stator FE model with CMS-based superelement modal reduction is developed. The method enables a high fidelity and efficient rotordynamic analysis for a newly designed power turbine (PT) with a slim spoke frame stator. In parallel, the stator support structure dynamic stiffness is quickly assessed using the FE simulated frequency response functions (FRF) data on the requirement of API standard. The results of the dynamic stiffness of the stator shows lower than the API standard recommended. The derived support dynamic stiffness is directly applied to the unbalance response analysis of the PT rotor incorporating the bearing characteristics. The comparison of the unbalance response shows that the rotor with FRF representation of stator structure and the full 3D FE superelement model are very well cross validated. Finally, the rotordynamic analysis of full FE model shows that with the slim spoke frame, the PT still meets all the API requirements.
This paper presents the development of a gas turbine simulator based on an application of a real turbogenerator used to generate electricity on an offshore oil platform, the configuration is a turboshaft with free power turbine. The compressor, turbines and the control system were developed using specific methodologies. The development of the simulator was done using the Simulink environment in Matlab®. The development was done using blocks to represent each one of the main components in the engine. A stage stacking methodology based on the real geometry for each stage was adopted to create the compressor maps. The map was used in lookup tables blocks with help of auxiliary coordinates, also known as beta lines. To model both turbines were applied an ellipse equation also known as Stodola's law. The engine simulator model was tested in an open loop and the results evaluated with the manual data from the engine.
Accurately estimating turbine cooling requirements at a preliminary design stage is crucial for modeling the overall propulsive system. The operating conditions of compressor, combustor and turbine are significantly influenced by these requirements. Empirical cooling models have thus far provided reliable initial estimations. For next-generation aero-engines this solution becomes inadequate. To address this challenge, an alternative semi-empirical approach based on an established cooling model is built into a collaborative turbine design tool chain. This cooling model is applied to the two cooled high-pressure turbines developed by P&W and GE within the NASA E3 program for both validation and to provide calibrated model parameters for future studies. Finally, sensitivity analysis provide a better understanding on how cooling requirements can be reduced through turbine preliminary design decisions, material and cooling technologies. This work focuses on 1D turbine studies with an accompanying paper on 0D engine modeling.
