Existing Gas Turbine Research Articles

Influence of AM Generated Burner Surface Roughness on NOx Emissions and Operability of Hydrogen-Rich Fuels

ABSTRACT The additive manufacturing (AM) technique enables the fabrication of advanced burner components to enhance the hydrogen capability of the existing gas turbines (GTs) and reduce the carbon footprints of the power generation sector. This technique produces rough surfaces that may require post-processing to maintain the desired functionality of a burner, particularly for hydrogen fuel with unique thermo-physical properties. This study, therefore, compared the stability of three swirlers of variable surface roughness manufactured using AM and traditional machining methods, with one of the AM swirler post-processed by grit-blasting. The comparison included a conventional benchmark (100% CH4), low carbon (23%volCH4/77%volH2) and zero carbon (100% H2) fuels across a range of equivalence ratios. Additionally, the study quantified the flame topology and emissions performance of the fuel blends for each swirler using high-speed OH* chemiluminescence and exhaust gas emissions measurements, respectively. The experimental investigation concluded that the AM-generated surface roughness within the considered range does not detrimentally impact NOX emissions and the stability of the fuel mix. However, the flame location was observed to be influenced by surface roughness and shifted more toward the vertical centerline of the burner with increased roughness. From the practical perspective, the results showed that post-manufacturing surface finishing offers negligible performance advantages, indicating potential cost reductions. It is recommended that further studies should investigate the influence of increased surface roughness on burner performance, as well as numerical modeling techniques which could provide an insight into when AM surfaces are likely to be more influential.

Emissions reduction in LNG production facilities through emerging post-combustion carbon capture and storage technologies

The liquefied natural gas (LNG) sector relies extensively on gas turbines for on-site power generation and to drive refrigeration compressors. They provide an efficient and reliable energy source for LNG operations in remote locations. With upcoming changes to the Safeguard Mechanism in Australia, there is an increased focus on Scope 1 emissions, so management and targeted reduction are a priority to reduce liabilities. Despite technology advancements, gas turbines remain one of the largest sources of carbon dioxide (CO2) emissions in LNG production facilities. Also, in Australia, many facilities are not grid-connected, meaning that displacement of Scope 1 emissions through renewable electricity sourcing is a challenge. To develop deeper cuts in Scope 1 emissions, one solution is to deploy post-combustion carbon capture and storage (CCS) on existing gas turbines, with the potential to reduce associated emissions by over 90%. Globally, a number of LNG facilities are already deploying CCS to permanently store reservoir CO2 from the LNG processing trains. Several Australian LNG facilities are located in close proximity to potential CO2 storage reservoirs, meaning that a coordinated approach to both reservoir and post-combustion CO2 should be considered when sizing pipelines, shipping systems and storage wells to optimise and leverage the required investment. This paper outlines the technological, economic and policy aspects of integrating both reservoir post-combustion CCS on LNG facilities, including barriers and opportunities for deployment. It will discuss new developments and enablers for CCS to be more widely deployed at LNG production sites.

Comparative Technical and Economic Analyses of Hydrogen-Based Steel and Power Sectors

Decarbonizing the current steel and power sectors through the development of the hydrogen direct-reduction iron ore–electric arc furnace route and the 100% hydrogen-fired gas turbine cycle is crucial. The current study focuses on three clusters of research works. The first cluster covers the investigation of the mass and energy balance of the route and the subsequent application of these values in experiments to optimize the reduction yield of iron ore. In the second cluster, the existing gas turbine unit was selected for the complete replacement of natural gas with hydrogen and for finding the most optimal mass and energy balance in the cycle through an Aspen HYSYS model. In addition, the chemical kinetics in the hydrogen combustion process were simulated using Ansys Chemkin Pro to research the emissions. In the last cluster, a comparative economic analysis was conducted to identify the levelized cost of production of the route and the levelized cost of electricity of the cycle. The findings in the economic analysis provided good insight into the details of the capital and operational expenditures of each industrial sector in understanding the impact of each kg of hydrogen consumed in the plants. These findings provide a good basis for future research on reducing the cost of hydrogen-based steel and power sectors. Moreover, the outcomes of this study can also assist ongoing, large-scale hydrogen and ammonia projects in Uzbekistan in terms of designing novel hydrogen-based industries with cost-effective solutions.

Ammonia blends for gas-turbines: Preliminary test and CFD-CRN modelling

Ammonia, with its high hydrogen density, cost effectiveness and ease of storage, is emerging as a potential fuel to meet decarbonisation targets in various sectors. However, the combustion of pure ammonia poses challenges due to its low calorific value and reactivity. Existing gas turbine combustion systems, refined over decades with conventional fuels, struggle to maintain comparable flue gas emission concentrations when burning ammonia.Overcoming this challenge requires a paradigm shift in gas turbine combustion, with implications for chemistry and combustor design methodology. Research into the chemical kinetic mechanism for ammonia combustion worldwide reveals differences in flame radical pools compared to methane combustion. The dominant NOx formation mechanism shifts to a "fuel-bound nitrogen" type, which differs from the "thermal" mechanism in hydrocarbon and hydrogen combustion.The integration of chemical reaction rates into Computational Fluid Dynamics (CFD) models with transport equations results in impractical computational times for industrial applications. Therefore, streamlined approaches such as chemical reaction reduction methods are being developed. This involves the construction of lumped parameter models (Chemical Reactor Network - CRN) to identify key parameters that affect species production. A reliable CRN implementation involves the identification of critical volumes using a preliminary CFD approach (CFD-CRN).This paper analyses preliminary experimental tests by Baker Hughes on an industrial burner using different ammonia, hydrogen, and methane fuel mixtures. The NOx results show a different behavior between methane and hydrogen. While the detailed mechanisms behind these results remain open questions, the CFD-CRN modelling approach is adopted. A proposed CRN is investigated for methane, hydrogen, and ammonia blends, providing insight into key parameters and a reasonable physical explanation for the different NOx results. A single calibration parameter (ϕpilot/ϕref) is used to predict accurately NOx emissions using experimental data available from experimental campaign.

Blend of flue gas from a methane-fueled gas turbine power plant and syngas from biomass gasification process to feed a novel trigeneration application: Thermodynamic-economic study and optimization

Enhancing the stability and cost-effectiveness of gas turbine power plants while mitigating input costs, co-feed arrangements, and multi-heat recovery processes shows great promise. The present study introduces an innovative trigeneration application to energetically and economically modify the existing gas turbine cycle. This trigeneration system incorporates several components, namely a helium gas turbine power plant, a regenerative steam Rankine cycle, a domestic water heating unit, and a multi-effect desalination subsystem. The thermodynamic and economic factors were considered to assess the performance indexes. Furthermore, a thorough technical analysis was conducted on the thermodynamic and economic variables, considering the influence of five crucial decision-making factors. Also, the operation mode of the system was optimized through multi-objective optimization of power and heating load. The outcomes of this optimization process revealed that the optimal values for electric power and heating load are 507.34 kW and 261.94 kW, respectively. Additionally, the capacity of freshwater obtained of about 0.076 kg/s. The optimal solution also showcased an exergy efficiency of 44.93 % and a relatively short payback period of 4.68 years, indicating the system's cost-effectiveness and favorable performance.

Power generation gas turbine performance enhancement in hot ambient temperature conditions through axial compressor design optimization

The output power and efficiency of gas turbines are profoundly influenced by ambient temperatures, with higher temperatures resulting in a notable decline in power output. This issue becomes particularly critical during periods of heightened power demand in hot climates. There are two common ways to solve this problem: incorporating auxiliary systems, such as inlet air cooling, or undertaking a comprehensive redesign of the gas turbine core engine. However, these methods sometimes are costly and unfeasible, particularly in regions characterized by arid conditions or constrained budgets for engine modifications. An alternative strategy has been developed to optimize axial compressor performance in order to improve gas turbine power in high-temperature environments, through an innovative approach. This approach centers on the concept of “re-staggering” the stator blades as a retrofit upgrade for existing gas turbines, enabling an increase in compressor inlet mass flow rate while maintaining peak efficiency at 45 °C. An in-house optimization tool was developed, incorporating a genetic algorithm and artificial neural network, to ascertain the optimal configuration of the re-stagger angles. This optimization process was initially coupled with a mean-line solver and subsequently refined using a through-flow model to enhance the preliminary design. The refined compressor design was then subjected to a comprehensive 3D Computational Fluid Dynamics analysis. Additionally, “end-bend” and “elliptical leading edge” techniques were employed to sustain compressor efficiency and ensure stability across various design and off-design operating conditions. Following a thorough structural analysis, the newly designed compressors were manufactured and tested at two distinct sites in Iran (Yazd and Bampur). The measured data demonstrated the commendable performance and stability of the redesigned compressors, aligning closely with numerical predictions. Notably, the results showcased a substantial increase in gas turbine power output ranging from 7.0% to 8.0% at hot ambient conditions, all while preserving efficiency and stability. Encouragingly, the upgraded compressor also exhibited superior performance even at lower temperatures, such as 15 °C. Consequently, this uprating concept presents a practical and cost-effective solution for power plant operators seeking a significant boost in power output, especially during hot weather conditions or in arid regions prone to drought.

Supercritical Carbon Dioxide Bottoming Cycles for Off-Shore Applications—An Optimization Study

Abstract Closed Joule–Brayton thermodynamic cycles working with carbon dioxide in supercritical conditions (sCO2) are presently receiving great attention, for their multiple attractive aspects: high energy conversion efficiency, compact size, flexibility of operation, and integration with energy storage systems. These features make the sCO2 technology interesting for several energy and industrial sectors, including renewable sources and waste heat recovery. A further promising area of application of sCO2 systems is bottoming gas turbines in combined cycles installed in off-shore platforms, where the lack of space complicates the application of steam Rankine cycles. The use of steam implies large-scale components and demands for large space availability for the plant installation; in such context, the combination of gas turbines with sCO2 cycles could open the way for developing novel combined cycles, which could be attractive for all the sectors which might take advantage from the footprint savings, the enhanced flexibility, and the fast dynamics of sCO2 systems. In this work, we investigate the thermodynamic potential of combining sCO2 cycles with an existing gas turbine for off-shore applications. We consider a midsize (25 MW) gas turbine available on the market and perform a series of thermodynamic optimizations of the sCO2 bottoming cycle to maximize the exploitation of the heat discharged by the gas turbine. We analyze four alternative configurations and include realistic technical constraints, evaluated by leveraging on the most recent technical outcomes from ongoing sCO2 research projects. A comparison is also proposed with a state-of-the-art steam Rankine cycle, in terms of system efficiency and footprint of the largest components. This study clarifies the advantages and challenges of applying sCO2 in combination with gas turbines, and it confirms the relevance of sCO2 systems for off-shore applications, calling for further technical studies in the field.

Demonstration of Natural Gas and Hydrogen Cocombustion in an Industrial Gas Turbine

Abstract Hydrogen cofiring in a gas turbine is believed to cover an energy transition pathway with green hydrogen as a driver to lower the carbon footprint of existing thermal power generation or cogeneration plants through the gradual increase of hydrogen injection in the existing natural gas grid. Today there is limited operational experience on cocombustion of hydrogen and natural gas in an existing gas turbine in an industrial environment. The ENGIE owned Siemens SGT-600 (Alstom legacy GT10B) 24 MW industrial gas turbine in the port of Antwerp (Belgium) was selected as a demonstrator for cofiring natural gas with hydrogen as it enables ENGIE to perform tests at higher H2 contents (up to 25 vol. %) on a representative turbine with limited hydrogen volume flow (one truck load at a time). Several challenges like increasing risk of flame flashback due to the enhanced turbulent flame speed, avoiding higher NOx emissions due to an increase of local flame temperature, supply and homogeneous mixing of hydrogen with natural gas as well as safety aspects have to be addressed when dealing with hydrogen fuel blends. In order to limit the risks of the industrial gas turbine testing a dual step approach was taken. ENGIE teamed up with the German Aerospace Center (DLR), Institute of Combustion Technology in Stuttgart to perform in a first step scaled-burner tests at gas turbine relevant operating conditions in their high-pressure combustor rig. In these tests the onset of flashback as well as the combustor characteristics with respect to burner wall temperatures, emissions and combustion dynamics were investigated for base load and part load conditions, both for pure natural gas and various natural gas and hydrogen blends. For H2 < 30 vol. % only minor effects on flame position and flame shape (analyzed based on OH* chemiluminescence images) and NOx emission were found. For higher hydrogen contents the flame position moved upstream and a more compact shape was observed. For the investigated H2 contents no flashback event was observed. However, thermo acoustics are strongly affected by hydrogen addition. In general, the scaled-burner tests were encouraging and enabled the second step, the exploration of hydrogen limits of the second generation dry low emissions burner installed in the engine in Antwerp. To inject the hydrogen into the industrial gas turbine, a hydrogen supply line was developed and installed next to the gas turbine. All tests were performed on the existing gas turbine hardware without any modification. A test campaign of several operational tests at base and part load with hydrogen variation up to 25 vol. % has been successfully performed where the gas composition, emissions, combustion dynamics and operational parameters are actively monitored in order to assess the impact of hydrogen on performance. Moreover, the impact of the hydrogen addition on the flame stability has been further assessed through the combustion tuning. The whole test campaign has been executed while the gas turbine stayed online, with no impact to the industrial steam customer. It has been proved that cofiring of up to 10% could be achieved with no adverse effects on the performance of the machine. Stable operation has been observed up to 25 vol. % hydrogen cocombustion, but with trespassing the local emission limits.

The investigation of an SGT5-2000E gas turbine power plant performance in Benin City based on energy analysis

• The effect of change in ambient air temperature on the performance of the SGT5 -2000E Gas turbine Power Plant was analyzed for this location. • The average net power output was 97.33% of the guaranteed value. • For this location, a 1 0 C rise in ambient air temperature, there are drops of 1.16% in net power output and 1.58% net thermal efficiency, a 1.58% increase in SFC and HR, and a 0.64% decrease in WR. • This study has suggested efficient ways of overcome drawbacks observed. In order to address the growing global energy demand and save energy from operating gas turbine power plants, the performance and losses from existing gas turbine power plants need to be studied. In view of this, this research work aims at carrying out the energy analysis of the SGT5-2000E Gas Power Plant for off-design conditions. The energy analysis was conducted using operating data collected from the power plant to evaluate the thermal efficiencies, specific fuel consumption (SFC), heat rate (HR), work ratio (WR) and energy losses with the aid of MATLAB software. The effects of ambient air temperature and compressor pressure ratio on the thermodynamic performance were carried out. Energy analysis results obtained showed that the average net thermal efficiency of the SGT5-2000E Gas Power Plant was found to be 30.21% at the ambient air temperature range from 21 to 35 0 C, the compressor pressure ratio of 10.73 to 10.96, the net power output of 148.92MW to 160. 70MW, and 60.16% of the fuel energy input was lost to the power plant surroundings as waste heat. Also, the results obtained revealed that for a 1 0 C rise in ambient air temperature, there are drops of 1.16% in net power output and 1.58% net thermal efficiency, a 1.58% increase in SFC and HR, and a 0.64% decrease in WR. Furthermore, the results obtained showed that there was a lower performance of the plant at high ambient air temperature and a lower compressor pressure ratio and the exhaust gas waste heat can be utilized for a combined heat and power system. Accordingly, the study has provided an understanding of suitable information about the power plant that can be used for efficient operation and waste minimization as ways of performance enhancement of the SGT5-2000E Gas Turbine Power Plant in Benin City.

Co-firing hydrogen and dimethyl ether in a gas turbine model combustor: Influence of hydrogen content and comparison with methane

To promote the utilization of hydrogen (H2) in existing gas turbines, dimethyl ether (DME) was used to co-fire with H2 in a model combustor. The swirl combustion characteristics of DME/H2 mixtures were measured under the varying H2 content up to 0.7. The results show that the flow velocity elevates as the H2 content increases, which is associated with the increased flame temperature. The OH level firstly increases and subsequently keeps nearly unchanged as the H2 content increases. Meanwhile, the OH area nonlinearly increases with the increasing H2 content. Moreover, the increasing H2 content induces almost linearly decreased lean blowout limit (LBO), increased NO emission, and intensified combustion acoustics. Furthermore, the combustion characteristics of the 0.46DME/0.54H2 mixture and CH4 with the same volumetric heat value were compared. The 0.46DME/0.54H2 flame displays lower LBO and higher NO emission than the CH4 flame, which mainly results from the higher reactivity of 0.46DME/0.54H2 mixture.

Mathematical Modelling of Marine Power Plants with Thermochemical Fuel Treatment

Abstract The article considers the methodological aspects of the theoretical investigation of marine power plants with thermochemical fuel treatment. The results of the study of the complex influence of temperature, pressure, and the ratio of steam / base fuel on the thermochemical treatment efficiency are presented. The adequacy of the obtained regression dependences was confirmed by the physical modelling of thermochemical fuel treatment processes. For a gas turbine power complex with a thermochemical fuel treatment system, the characteristics of the power equipment were determined separately with further merging of the obtained results and a combination of material and energy flow models. Algorithms, which provide settings for the mathematical models of structural and functional blocks, the optimisation of thermochemical energy transformations, and verification of developed models according to the indicators of existing gas turbine engines, were created. The influence of mechanical energy consumption during the organisation of thermochemical processing of fuel on the efficiency of thermochemical recuperation is analysed.

Analysis of the combustion characteristics of hydrogen and hydrocarbon fuels based on the results of numerical simulation

At present, an upward trend in the field of studying the processes of hydrogen combustion in the combustion chambers of the ground-based gas turbine power plants is obvious. The use of pure hydrogen as a fuel gas would solve the problem of environmental decarbonization. One of the emerging problems is to ensure the stable combustion of such fuels in combustion chambers of various applications. The information-analytical review of studies showed that there is a large number of theoretical and experimental results on the diffusion and homogeneous combustion of hydrogen and hydrogen-containing fuels in various burners and combustion chambers, which are not part of the existing gas turbine power plants. The purpose of this work is a comparative analysis of the gas-dynamic and emission characteristics of the combustion of the hydrogen-air and methane-air components based on the results of numerical simulation of a convertible combustion chamber of a 75 kW microgas turbine power plant. This goal is achieved by numerical simulation of the diffusion combustion of hydrogen and methane with air in a convertible combustion chamber. The most significant result of the work is obtaining the isosurface of the flame, which made it possible to obtain the conditions for stable combustion in the form of the Damköhler criterion and the ratio of the midsection velocity to the velocity of turbulent combustion. The significance of the results obtained lies in the further development of the methodology for the conversion of megawatt-class gas turbine plants to hydrogen and hydrogencontaining fuels.

Increasing the efficiency and reliability of gas turbine power plants through the use of additive technologies

The article is dedicated to the study of the feasibility of increasing the efficiency, reliability and manufacturability of existing gas turbine power plants with additive technologies that allow creating recuperators with regeneration degrees of 90...95%. The characteristics are presented for the following gas turbine power plants: TEEDA (Iran) 3.13 MW, ODK Perm Motors GTU-4P (Russia) 4.13 MW, Siemens SGT-100 (Germany) 5.1 MW, Solar Turbines Taurus 60 (USA) 5.67 MW. The research was carried out using the methods and programs of the Higher School of Power Engineering for the calculation of thermal circuits of GTPP. The dependences of effective efficiency, work ratio, effective specific work and specific consumption of conventional fuel of GTPPs under examination on compressor pressure ratio and regeneration factor are obtained. Solving the problem of increasing the regeneration factor in GTPP (above 0.9) requires the development of special designs of heat exchanger matrices of the recuperator, which is only possible with the use of additive technologies and new heat-resistant materials. Promising recuperators have a more complex design of heat exchange matrices, which ensures their being very compact. Such technical solutions can ensure the development and creation of fundamentally new designs of GTPP heat exchangers and significantly improve their technical characteristics.

Integration of MHD System to The Gas Turbine and The Steam Turbine Power Plant: A Brief Review

Electrical energy generation is essential for the survival of the modern society. Fossil fuels are limited and create pollution. Also the conventional power generation systems using fossil fuel have lesser efficiency due to higher amount of losses in different sections of the plants. The Magnetohydrodynamic (MHD) is found as a nonconventional energy generation system which has the capability to enhance the thermal power plant efficiency significantly. The MHD is a direct energy conversion system that describes the interactions of a magnetic field and an electrically conductive fluid to produce electrical power. The system is simple and it avoids the difficulty of choosing a rotating turbine or engine and massive number of complex calculations. The high temperature tolerable materials can be used in the system due to the exponential development of material science. In MHD system, energy of plasma or ionized gas is directly converted into electric power. The conversion process of the system is based on the principle of Faraday’s Laws of electromagnetic induction and fluid dynamics. The MHD generator uses hot conductive ionized gas or plasma as the moving conductor whereas in the mechanical dynamo, in contrast, uses the motion of mechanical devices to accomplish this. Seeding materials such as potassium carbonate, potassium sulphates are used to enhance the conductivity of the ionized gas. The focus of the present study is to investigate alternative methods through which an MHD power generator can be coupled to the existing gas turbine and steam plants. In doing so, the thermal cycle efficiency of these conventional plants can be improved. A case study is also presented to calculate the power output and efficiency in a simple way.

СОВЕРШЕНСТВОВАНИЕ ПРОИЗВОДСТВЕННОГО ЦИКЛА ИЗГОТОВЛЕНИЯ ДЕТАЛЕЙ ПРИ ОБЕСПЕЧЕНИИ ПАРАМЕТРОВ СЕЛЕКТИВНОЙ СБОРКИ УЗЛА

The problem of production cycle improving of the gas turbine engine unit is considered. The analysis of existing gas turbine engine unit production cycle was carried out and the identification of its main shortcomings are considered. The paper purpose is to develop a new production cycle for release the products with the assembly quality increase in a shorter production time, the use of selective assembly with the repeated cycles exclusion and with use of an electronic database replenished with actual dimensions using a control and measuring machine, which will speed up the process of controlling parts for compliance assembly requirements.

Evolution of Iran’s gas turbine sectoral innovation system as a complex product system (CoPS)

Many scholars have studied various sectoral innovation systems that are categorized as mass-produced goods, whereas there are only a few previous studies that have investigated complex product systems (CoPS). CoPS are defined as high-cost, engineering, and software-intensive goods, systems, networks, infrastructure, engineering constructs, and services. However, many differences between these two categories of industries have been reported by a large number of scholars. To address this shortcoming, this paper intends to study the evolution of Iran’s gas turbine sectoral innovation system as a CoPS industry. To this end, a qualitative approach and a case study research design were employed. To do this, we conducted 17 in-depth interviews, participated in different conferences and conventions, as well as studied various documents as secondary data. Our findings suggest that: firstly, technological capabilities in Iranian gas turbine producers have evolved from assembling to manufacturing, and re-designing existing gas turbines; Secondly, diverse and dynamic governmental policies associated with the gas turbine industry over the last two decades have played a key role in encouraging domestic firms to acquire technological capabilities; and thirdly, the large and growing domestic market not only justified investing in R&D and building infrastructure by the government but also contributed to improved interaction and collaboration between domestic and overseas’ companies. As the main policy implication, our paper suggests that the transition from product-using to product-manufacturing in CoPS industries is not an automatic process. It is important to design the corresponding policies and institutional arrangements following the evolving technological capabilities and demand conditions. Finally, this paper has contributed to sectoral innovation systems and CoPS literature by shedding light on the evolution of the gas turbine industry as CoPS in the context of Iran as a developing country with some restrictions in global technology collaborations.

Development of novel mathematical models of plate heat exchanger for the task of optimization main parameters of the aviation gas turbine engine with heat recovery

Nowadays, the task of increasing the economic and technical efficiency of the gas turbine engine and decrement of the specific weight and specific fuel consumption is one of the main targets in the development of the aviation gas turbine engine. A promising approach for decrement of specific fuel consumption and obtaining high thermal efficiency of the gas turbine engine (30% and above) is based on the concept of the recuperative cycle of the gas turbine engine. The article presents the computer-aided calculation for analysing the heat exchanger surface and developing novel mathematical models of heat exchanger in terms of weight goodness, flow passage goodness, and optimum weight and flow passage, furthermore, the study presents the novel mathematical models of the pressure drops in the air and gas channels of the heat exchanger. 18 different heat transfer surfaces for heat exchanger cores have been evaluated and the results are presented. The same hydraulic diameter assumed for all heat transfer surfaces and only their thermo-hydraulic performances evaluated during the calculation design. To assess the reliability of the obtained models, the results of the design calculations of the developed models compared with the data of other authors and with the data of the existing gas turbine engine with heat exchanger. The obtained models focus on mathematical design calculation for optimizing the main thermodynamic parameters of a gas turbine engine coupled with a heat exchanger at the stage of conceptual design of aviation gas turbine engine with heat recovery of exhaust gas.

Artificial Neural Network based Process History Data Model for Gas Turbine Compressor Systems

Gas turbine-based power plants are found to play a vital role in electric power generation and act as spinning reserves for renewable electric power. A robust performance assessment tool is inevitable for a gas turbine system to maintain high operational flexibility, availability, and reliability at different operating conditions. A suitable simulation model of the gas turbine provides detailed information about the system operation under varying ambient and load conditions. This paper illustrates a systematic methodology for process history data-based modelling of a gas turbine compressor system. The ReliefF feature selection method is applied for the proper identification of the parameters influencing the compressor efficiency. Appropriate Artificial Neural Network (ANN) based models are developed for data classification and system modelling of the compressor. The model performance has been validated using actual plant operational data, and the standard deviation of the error in model output was found to be 0.38. A novel approach for suitable integration of data processing methods, machine learning tools and gas turbine domain knowledge has led to the development of a robust compressor model. The model has been utilized for the health assessment of an existing gas turbine compressor, demonstrated through an illustrative case study. The model has been found suitable for parametric analysis of compressor efficiency with operating hours, which is helpful for operational decision-making involving studies on the influence of part-load operation, compressor wash planning, maintenance planning etc.

Design point analysis of two-shaft gas turbine engines topped by four-port wave rotors for power generation systems

Wave rotors are rotating equipment designed to exchange energy between high and low enthalpy fluids by means of unsteady pressure waves. In ground power plants, they can be used as topping devices to existing gas turbines aiming to improve their performance characteristics. A four-port wave rotor is an attractive configuration to be integrated into the gas generator of a two-shaft gas turbine, typical for power generation and propulsion systems, by slightly modifying the architecture of existing engines. In particular, in the present article the wave rotor-topped engine utilizes the same compressor, combustion chamber and turbine inlet temperature of the baseline engine. Cycle analysis for two-shaft gas turbine engines topped with four-port wave rotors is studied and their performance at design point is compared to the performance of the baseline engines accordingly. It is concluded that important benefits are obtained with respect to the ones of the baseline engines in terms of specific work and specific fuel consumption. Furthermore calculations by varying the pressure ratio within the wave rotor and the pressure losses in the ducts connecting the wave rotor to the engine's components indicate the effect on performance, for engines with different compressor pressure ratios and turbine inlet temperatures.

Thermo-economic analysis of a heat recovery steam generator combined cycle

A significant amount of energy gets lost through the exhaust of simple gas turbine plants, more often than not, this energy can be used to run another power cycle or a combined heat and power setup, leading to an increase in the overall efficiency of the plant, reduce air pollution and energy wastage. In this study, a retrofitted performance analysis of incorporating a steam power cycle to the existing gas turbine cycle in Delta IV power station is carried out, the analysis is carried out using first law of thermodynamics and energy cost comparison to describe the effect of combining both cycles on power output, thermal efficiency and energy cost. Operating data were obtained from existing gas thermal plant in Ughelli (Delta IV) and steam thermal plant in Lagos (Egbin). Preliminary assessment shows that power output increases by a further 51.5MW, thus raising the overall combined efficiency to 41.85%. Analysis on cost savings accruable from incorporating a heat recovery steam generation was also done and significant savings in cost was obtained. Keywords: combined cycle, HSRG, gas turbine, steam turbine, energy cost