Turbine Compressor Research Articles

Investigation of the Difference Between Ordinary and FSI Numerical Solution for Flutter of Tandem Compressor

This research aims to analyze and compare the flutter of turbine compressor blades from experimental, numerical, and fluid structure interaction (FSI) derived data. The results proved that the FSI solution results are closer to the experimental results. A reduced velocity parameter of 5 can be regarded as the flutter boundary in the bending flutter. Additionally, the incidence angle parameter equal to 1.5 can be characterized as the torsional flutter boundary. Tandem leads to strengthening the load applied on the compressor blades, reducing the number of compressor stages, and ultimately reducing the weight of the engine. Adding tandem to the rotor increases the vibration bending frequency by a factor of 2. Increasing the compressor velocity caused the FSI vibration frequency to be close to the experimental results. It was found that the vibration range of the main rotor is greater than that of the tandem. The vibration of the rotor and the tandem is damped for approximately 0.1 s to reach a constant frequency.

Synchronous Vibration Parameter Recognition of Constant-Speed Blades Based on Blade Tip Clearance Measurement

A new method for the synchronous vibration parameter identification of constant-speed rotating blades based on blade tip clearance (BTC) measurement and blade tip timing (BTT) is introduced. A BTC sensor is used to measure the BTC when the blade tip passes through each sensor. The BTT method is used to determine whether the blade tip arrives in advance or lags. The geometric model between the BTC and the blade tip vibration displacement (BTVD) is established, and the BTVD of the blade tip passing through each sensor is obtained. Then, the nonlinear least squares method is used to determine the synchronous vibration parameters of the constant-speed rotating blade. The results show that with an increase in amplitude, the higher the accuracy of the vibration parameter identification proposed in this paper; with a decrease in the random error of the BTC measurement, the higher the accuracy of the vibration parameter identification proposed in this paper; with a decrease in the random error in the measurement of the blade disk dimensions, the higher the accuracy of the vibration parameter identification proposed in this paper. In addition, the smaller the ratio of the blade length to the blade disk radius, the higher the accuracy of the vibration parameter identification method introduced in this paper. Because the structure of the gas turbine compressor and turbine blade disk has a small blade disk ratio, the method proposed in this paper is suitable for the simultaneous vibration parameter identification of gas turbine compressor blades and turbine blades.

Optimal design and performance assessment of a proposed constant power operation mode for the constant volume discharging process of advanced adiabatic compressed air energy storage

A power operation mode of constant volume discharging process for advanced adiabatic compressed air energy storage (AA-CAES), called compensation mode (C mode), is proposed. The dynamic model of the proposed C mode discharging process is established based on the conservations of mass, momentum, and energy. The reliabilities of compressor, air tank, and air turbine are verified separately. The optimal design is carried out to reduce the power consumed by the compressor. The optimal design pressure ratio and reduced flow rate are 2.48 and 9.292 × 10−5 m·s·K0.5, respectively. This finding proves that the proposed dynamic model obeys the first and second laws of thermodynamics. The exergy distribution of the entire discharging process is studied. Results show that the two largest exergy losses occur in MT and MR. The performance of the proposed C mode is compared with that of the two other operation modes. The proposed C mode enhances the energy storage efficiency of the AA-CAES system by 14.71 %. This study provides a relatively efficient and feasible technical solution for the constant power operation of AA-CAES.

Comparative Evaluation for Selected Gas Turbine Cycles

The energy and exergy evaluation of simple gas turbine (SGT), gas turbine with air bottoming cycle (GT-ABC), and partial oxidation gas turbine (POGT) are studied. The governing equations for each cycle are solved using energy equation Solver (EES) software. The characteristics performance for selected cycles are discussed and verified with that obtained for available practical cycles (SGT, GT-ABC, POGT). The present results show a good agreement with the practical one. The effects of significant operational parameters, turbine inlet temperature (TIT), compression ratio (CR), and compressor inlet temperature (CIT), on the specific fuel consumption, energy and exergy efficiencies are discussed. According to the findings, a reduction in CIT and a rise in TIT and CR led to enhance energy and exergy efficiency for each configuration with different ranges. Results revealed that the GT-ABC and POGT cycles are more efficient than those of SGT at the same operational parameters. The energy and exergy efficiencies are 38.4%, 36.2% for SGT, 40%, 37.8 % for GT-ABC, and 41.6%, 39.3% for POGT. The POGT cycle has a better energy and exergy performance at a lower pressure ratio than the SGT and GT-ABC.

Tip Rubbing as a Rare Metallurgical Root Cause of Gas Turbine Compressor Blade Failure

Tip Rubbing as a Rare Metallurgical Root Cause of Gas Turbine Compressor Blade Failure

Thermodynamic feasibility and multiobjective optimization of a closed Brayton cycle-based clean cogeneration system

The present research has analyzed the energy and exergy of a combined system of simultaneous power generation and cooling. To provide a comprehensive data sheet of this system, the system has been investigated in the temperature range of 300–800 °C, and 6 working fluids, including air, carbon dioxide, nitrogen, argon, xenon, and helium, have been investigated. The parameters affecting the performance of the system, namely the compressor inlet pressure, the compressor pressure ratio, and the intermediation pressure ratio were investigated. The power produced by the Brayton cycle at a pressure ratio of 5.2 is the highest due to the increase in compressor power consumption and turbine power generation. The results of the parametric study showed that the exergy efficiency of the system has the maximum value at the pressure ratio of 4.73. The results of the parametric study showed that increasing the pressure of the compressor does not have a significant effect on the electricity consumption and the temperature of the working fluid due to the constant pressure ratio. The input energy to the heat exchanger of the absorption chiller decreases with the increase in the Brayton cycle pressure ratio, and as a result, the cooling created by the chiller also decreases. In this method, three objective functions of exergy efficiency, energy efficiency, and total production power are considered as objective functions. The most optimal value of intermediation pressure ratio was obtained after the optimization process of 1.389. Also, the most optimal value of the pressure ratio of high-pressure and low-pressure turbines was reported as 2.563 and 1.845, respectively.

Efficient turbomachinery layout design and performance comparison of supercritical CO2 cycles for high-temperature concentrated solar power plants under peak-shaving scenarios

The supercritical CO2 (S–CO2) cycle with high operating temperature for the next-generation concentrated solar power (CSP) technology are constructed. The turbomachinery layouts are designed and operating parameters are optimized to efficiently and flexibly respond to part-load operating conditions. The thermodynamic performance advantages of CSP plant based on S–CO2 cycle with high temperature and optimized turbomachinery layout under peak-shaving scenarios are clearly indicated. Results show that compared with the cycle with split shaft layout, the optimization of cycle turbomachinery layout can improve the part-load efficiencies of the cycle by 0.47%–2.33 %. The cycle connecting the turbine and main compressor is recommended to be adopted for deep peak-shaving scenarios, and its efficiency at 30 % rated load is only reduced to 86.3 % of the rated value. While the cycle connecting the turbine and re-compressor maintains superior efficiency performance when the load exceeds 60 % of the rated value. Furthermore, the increase of operating temperature to 750 °C and optimization of cycle turbomachinery layout can improve the efficiency of CSP plant to 21.60 % under PV-CSP peak-shaving scenarios, which is 0.55 % higher than that of the system based on cycle with split shaft layout and 2.18 % higher than that of the conventional CSP plant with 550 °C operating temperature.

Improving the Microstructure and Wear Behavior of Gas Turbine Compressor Parts Through the Application of FeCoNiCuAl–WC High Entropy Composite Coating by Laser Cladding

Improving the Microstructure and Wear Behavior of Gas Turbine Compressor Parts Through the Application of FeCoNiCuAl–WC High Entropy Composite Coating by Laser Cladding

Analysis of the Efficiency of a Power Generating Plant Operating on the Basis of the Brayton Thermodynamic Cycle and Energy Recuperation

The thermal scheme of a power generating plant with a remote heat exchanger operating according to the Brayton cycle with energy recuperation is considered. It is assumed that the plant will work on non-certified (cheap) biofuel. It is shown that, in contrast to the usual Brayton cycle, in the cycle with energy recuperation, the greatest influence on the thermal efficiency is the heating temperature of the working medium and the internal efficiency of the main components of the plant, such as the compressor and the turbine. Also, in contrast to the usual Brayton cycle, a higher efficiency of the plant is achieved with smaller degrees of pressure reduction (increase) in the turbine (compressor). It was established that even at a relatively low temperature of the working medium heating (500 ºC), with high efficiency of the compressor and turbine, it is possible to achieve good characteristics of the power plant as a whole. At a temperature of up to 850 ºC, a thermal efficiency of 40% is achieved, but in this case the cost of materials and production increases. For a final conclusion about the possibility of using the proposed plant and its efficiency, it is necessary to conduct additional studies, in particular, of its main elements, such as a compressor, turbine, heat exchanger and others.

Advanced fuel limit design to improve dynamic performance of marine three-shaft gas turbine

Gas turbine powered integrated power system can effectively supply for shipboard weaponry, representing an obvious developing trend of world naval ship power. However, in the large pulsed power load environment, system stable operation still suffers from insufficient gas turbine power response. In order to improve the dynamic performance and transient stability of three-shaft gas turbine, in this paper, fuel limit design is focused to a novel perspective. As a basis, a high accuracy model of three-shaft gas turbine is established, the model accuracy is validated against actual test data. By decoupling and analyzing multi-inertia coupling structure of three-shaft gas turbine, a transient performance prediction method is proposed, and the advanced fuel limit design considering multiple factors such as compressor surge, turbine overtemperature and combustor lean blowout is suggested. MATLAB/Simulink simulations are carried out to present the performance of advanced fuel limit design under different operating conditions. The simulation results indicate that, in a set large pulsed power load environment, the upgraded fuel limit could increase fuel flow rate and power response by a multiple of approximately 3.1 while satisfying safe indicators, reducing the transient speed regulation from 21.7 % to 7.2 %, meeting the stability capability to adapt for load impact.

Enhanced compression heat recovery of coupling thermochemical conversion to trigenerative compressed air energy storage system: Systematic sensitivity analysis and multi-objective optimization

Compressed air energy storage system has been considered as a promising alternative solution for stabilizing the electricity production driven by intermittent renewable energy sources. However, the inefficient utilization of thermal energy within the compressed air energy storage system hinders the efficient operation of system. Therefore, a novel trigenerative system integrated compressed air and chemical energy storage system is introduced in this study. The proposed system transforms the compression heat to the syngas in the form of chemical energy to achieve energy level upgradation during the charging process, and recuperates the thermal energy at the exit of the gas turbine to increase the inlet temperature of the compressed air for electricity enhancement during the discharging process. The residual heat during the operation process is then conducted for producing cooling and heating outputs simultaneously based on the law of energy cascade utilization. A systematic parametric analysis is carried out to investigate the effects of critical parameters on system comprehensive performance. Furthermore, the multi-objective optimization is employed to find the optimal trade-off among the thermodynamic performance, economic attractiveness and environmental friendliness of the proposed system. The parametric analysis indicates that the operating parameters of air compressor and gas turbine affect the performance indicators of thermodynamic and economic significantly. Moreover, at the best trade-off solution selected by the TOPSIS method, the system reaches 42.96 % of exergetic round trip efficiency, 105.28 $/MWh of levelized cost of energy and 206.94 kg/MWh of CO2 emission per unit energy output.

Dynamic particle swarm optimization-radial function extremum neural network method of HCF probability analysis for compressor blade

The high cycle fatigue (HCF) of compressor rotor seriously affects the performance and reliability of gas turbine. Probabilistic HCF evaluation is an effective measure to quantify the uncertain traits of vibration stresses and assess the reliable HCF life for compressor rotor. To improve modeling accuracy and computational efficiency in transient probability analysis of HCF life of gas turbine compressor, radial basis function neural network (RBFNN) and dynamic particle swarm optimization (DPSO) algorithm were introduced into extreme response surface method (ERSM). In this paper, we propose a HCF life probability evaluation method for compressor blades based on the dynamic particle swarm optimization-radial basis function extremum neural network (DPSO-RBFENN) model. By selecting random input variables such as aerodynamic load, centrifugal load and material parameters, a prediction model was established based on DPSO-RBFENN sample learning, and the reliability evaluation of compressor blade HCF life was carried out. Distribution characteristics, reliability and sensitivity to fatigue life were obtained, which provided a basis for the structural design of compressor blades. The Monte Carlo method, ERSM, RBFNN and DPSO-RBFENN are compared.

Multidimensional analysis and performance prediction of heavy-duty gas turbine based on actual operational data

This study aims to analyze and predict the degradation, safety and operational performance of a heavy-duty gas turbine based on actual operational data after running for a long time. The dataset consists of 288,039 operational records from the Ban Shan Power Plant. The data is screened using Pearson correlation coefficients and 2-means clustering. Then, efficiency degradation of compressor and gas turbine is conducted by decoupling operation state from degradation. Next, Long short-term memory(LSTM) is employed to build data-driven T-model based on algorithm structure similarity. Meanwhile, the safety requirements containing the compressor surge and turbine inlet temperature boundary are determined, which are considered in operational performance analysis. Results show that abnormal operation data is identified during operational times 37, 38, 39, 40, 41, 42, and 248. After 254,341 minutes, the compressor efficiency degrades nearly 1%. The surge margin of a compressor is a binary function of the corrected air mass flow and inlet guide vane (IGV). The pressure ratio of the working margin moves downward by 0.11 for each 1° increase in IGV. What’s more, the T-model demonstrates high accuracy and can predict operational performance at high environmental temperatures, with the accuracy of turbine outlet temperature within 0.995. The unit is particularly sensitive to IGV, natural gas flow mass, compressor inlet temperature, and turbine outlet gauge pressure. When the relative humidity is 68%, the electrical power is the highest and overall efficiency is the best. Overall, this study's approach has significant potential for multidimensional analysis and performance prediction.

Numerical Solution of Inviscid and Viscous Flow Across NACA0010 Airfoil with different Angles of Attack

The role of the airfoil in all engineering fields is very important. Airfoil designs are utilized in various applications such as aircraft wings, helicopter rotor blades, sails, fans, and turbine compressors. In the case of aircraft, airfoils are accountable for generating lift force and determining if it is adequate for balancing the aircraft's weight, as well as determining the amount of drag force that should be applied to the body. They also play a vital role in optimizing blade performance, as well as the heat and operational efficiency of turbines. Airfoils are moving in the flow passing by them, and they show different responses based on many parameters such as whether the flow is smooth or turbulent, viscous or inviscid, flow velocity, angle of attack, multidimensionality of velocity components, etc. For aeronautics vehicles and wind turbines, a large number of studies have been conducted to analyze aerodynamic forces on two dimensional airfoils as well as flow phenomena associated with different Reynolds numbers. Main object of this research is to figure out the flow characteristics around the airfoil body and analyze aerodynamic performance of airfoil. In order to investigate the computational efficiency of flow models, numerical examination has been done for flow across NACA0010 airfoil by using 2D Computational Fluid Dynamics (CFD) solver, ANSYS FLUENT 18.0, at various angle of attack (0o to 13o) for inviscid flow and (-30o to 30o) for viscous flow. Lift and drag coefficients and C p for lower and upper airfoil surface and velocity diagram based on different angle of attack has been solved for the sample under two different flow regimes. The contours of velocity were simulated, and stall point was noticed from 13° angle of attack in inviscid flow and 24o in viscous flow. In the non-viscous state, lift coefficient and drag coefficient was higher, in comparison with viscous flow.

Numerical studies of air humidity importance in the first stage rotor of turbine compressor

Numerical studies of air humidity importance in the first stage rotor of turbine compressor

Techno-economic and environmental optimization of a combined regenerated gas turbine and supercritical CO2 cycle based on methane and hydrogen mixture as fuel for environmental remediation

Achieving power generation systems with high efficiency and low emission of environmental pollutants is one of the requirements of a sustainable environment. In this study, a hybrid power generation system based on gas turbine (GT) with regenerator configuration is introduced. A supercritical carbon dioxide (sCO2) cycle is used to recover the waste heat from GT exhaust gases. In order to reduce the emission of environmental pollutants, the combination of hydrogen and methane is used as GT fuel. In order to investigate the effect of using hydrogen in the fuel composition, the fraction of hydrogen is changed between 0 and 50% and its effect on performance, environmental, and economic factors is investigated. Also, the effect of design parameters such as compressor pressure ratio (CPR) and turbine inlet temperature (TIT) of GT and sCO2 cycles on exergy efficiency, total cost rate (TCR), and normalized pollutants emission index are investigated. Then, by performing a bi-objective optimization process with the aim of achieving maximum exergy efficiency and minimum TCR, the optimal operating point is extracted. At the optimal operating point, exergy efficiency is 44% and TCR is 6 dollars/second.

Techno-Economic Analysis and Optimization of a Compressed-Air Energy Storage System Integrated with a Natural Gas Combined-Cycle Plant

To address the rising electricity demand and greenhouse gas concentration in the environment, considerable effort is being carried out across the globe on installing and operating renewable energy sources. However, the renewable energy production is affected by diurnal and seasonal variability. To ensure that the electric grid remains reliable and resilient even for the high penetration of renewables into the grid, various types of energy storage systems are being investigated. In this paper, a compressed-air energy storage (CAES) system integrated with a natural gas combined-cycle (NGCC) power plant is investigated where air is extracted from the gas turbine compressor or injected back into the gas turbine combustor when it is optimal to do so. First-principles dynamic models of the NGCC plant and CAES are developed along with the development of an economic model. The dynamic optimization of the integrated system is undertaken in the Python/Pyomo platform for maximizing the net present value (NPV). NPV optimization is undertaken for 14 regions/cases considering year-long locational marginal price (LMP) data with a 1 h interval. Design variables such as the storage capacity and storage pressure, as well as the operating variables such as the power plant load, air injection rate, and air extraction rate, are optimized. Results show that the integrated CAES system has a higher NPV than the NGCC-only system for all 14 regions, thus indicating the potential deployment of the integrated system under the assumption of the availability of caverns in close proximity to the NGCC plant. The levelized cost of storage is found to be in the range of 136–145 $/MWh. Roundtrip efficiency is found to be between 74.6–82.5%. A sensitivity study with respect to LMP shows that the LMP profile has a significant impact on the extent of air injection/extraction while capital expenditure reduction has a negligible effect.

Exergo–Economic and Parametric Analysis of Waste Heat Recovery from Taji Gas Turbines Power Plant Using Rankine Cycle and Organic Rankine Cycle

This study focused on exergo–conomic and parametric analysis for Taji station in Baghdad. This station was chosen to reduce the emission of waste gases that pollute the environment, as it is located in a residential area, and to increase the production of electric power, since for a long time, Iraq has been a country that has suffered from a shortage of electricity. The main objective of this work is to integrate the Taji gas turbine’s power plant, which is in Baghdad, with the Rankine cycle and organic Rankine cycle to verify waste heat recovery to produce extra electricity and reduce emissions into the environment. Thermodynamic and exergoeconomic assessment of the combined Brayton cycle–Rankine cycle/Organic Rankin cycle (GSO CC) system, considering the three objective functions of the First- and Second-Law efficiencies and the total cost rates of the system, were applied. According to the findings, 258.2 MW of power is produced from the GSO CC system, whereas 167.3 MW of power is created for the Brayton cycle (BC) under the optimum operating conditions. It was demonstrated that the overall energy and exergy efficiencies, respectively, are 44.37% and 42.84% for the GSO CC system, while they are 28.74% and 27.75%, respectively, for the Brayton cycle. The findings indicate that the combustion chamber has the highest exergy degradation rate. The exergo–economic factor for the entire cycle is 37%, demonstrating that the cost of exergy destruction exceeds the cost of capital investment. Moreover, the cost of the energy produced by the GSO CC system is USD 9.03/MWh, whereas it is USD 8.24/MWh for BC. The results also indicate that the network of the GSO CC system decreases as the pressure ratio increases. Nonetheless, the GSO CC system’s efficiencies and costs increase with a rise in the pressure ratio until they reach a maximum and then decrease with further pressure ratio increases. The increase in the gas turbine inlet temperature and isentropic efficiency of the air compressor and gas turbine enhances the thermodynamic performance of the system; however, a further increase in these parameters increases the overall cost rates.

Thermo-economic and environmental assessment of a combined cycle fueled by MSW and geothermal hybrid energies

The hybrid renewable energy-based power generation systems offer a reliable solution to mitigate the drawbacks of individual energy source. In this respect the biomass and geothermal energies have some well-known advantages (such as continuous provision) over the solar and wind energies. In the present paper, two integration modes are proposed for hybridization of geothermal heat with a biomass-driven gas turbine based combined power cycle. The Mode 1 configuration employs geothermal heat to increase the temperature of feedwater before the deaerator, whereas the Mode 2 structure applies the geothermal energy to generate more steam for the low pressure steam turbine. Detailed exergetic, environmental and economic appraisals are carried out to examine the hybrid systems performances. In order to represent an accurate comparison of the suggested hybridization modes, the systems are optimized to achieve minimum levelized electricity cost. The results have indicated better performance for Mode 2 hybridization scenario over the Mode 1. The former system yields 10.0% greater exergy efficiency with 20.1% less electricity cost compared to Mode 1, while it can generate 22.5% more electricity. Also, it brings about 22.5% lower CO2 emission. However, the Mode 2 configuration possess one drawback compared to Mode 1, which is its higher overall system cost rate by 17.9%. The results show that, the higher cost rate of Mode 2 configuration is mainly due to larger pressure ratio of the air compressor which causes more costs for the compressor and gas turbine components.

Numerical Study on Vibration Response of Compressor Stator Blade Considering Contact Friction of Holding Ring

There are many kinds of assembly structures in heavy-duty gas turbine compressor stator blades which have significant influence on the complex damping vibration characteristics. At present, compressor design is becoming more and more compact, so it is very meaningful to accurately obtain stator blade vibration characteristics of structures with contact damping. Firstly, a fretting slip friction dynamic model was introduced, and then a vibration analysis model of the compressor stator blade with outer ring structure was established based on the slip friction theory. Then, the vibration response of the compressor stator blade was obtained according to various working conditions, and the main factors affecting the vibration characteristics of the stator blade were revealed. Finally, the vibration response of the blade under a particular exciting force condition was simulated. The results show that the damping vibration characteristics of the compressor stator blades were affected by the excitation force and the normal load of the contact surface. The vibration response curve of the stator blade and the equivalent stiffness coefficient of the contact surface were analyzed, and the friction motion of the contact surface changed with the change of the working condition. The model can simulate the nonlinear vibration characteristics of stator blades. This method provides a reference for the vibration safety analysis of compressor stator blades.