Micro Gas Turbine Research Articles

Micro Gas Turbines in the Global Energy Landscape: Bridging the Techno-Economic Gap with Comparative and Adaptive Insights from Internal Combustion Engines and Renewable Energy Sources

This paper investigates the potential of Micro Gas Turbines (MGTs) in the global shift towards low-carbon energy systems, particularly focusing on their integration within microgrids and distributed energy generation systems. MGTs, recognized for their fuel flexibility and efficiency, have yet to achieve the commercialization success of rival technologies such as Internal Combustion Engines (ICEs), wind turbines, and solar power (PV) installations. Through a comprehensive review of recent techno-economic assessment (TEA) studies, we highlight the challenges and opportunities for MGTs, emphasizing the critical role of TEA in driving market penetration and technological advancement. Comparative analysis with ICE and RES technologies reveals significant gaps in TEA activities for MGTs, which have hindered their broader adoption. This paper also explores the learning and experience effects associated with TEA, demonstrating how increased research activities have propelled the success of ICE and RES technologies. The analysis reveals a broad range of learning and experience effects, with learning rates (α) varying from 0.1 to 0.25 and experience rates (β) from 0.05 to 0.15, highlighting the significant role these effects play in reducing the levelized cost of energy (LCOE) and improving the net present value (NPV) of MGT systems. Hybrid systems integrating MGTs with renewable energy sources (RESs) and ICE technologies demonstrate the most substantial cost reductions and efficiency improvements, with systems like the hybrid renewable energy CCHP with ICE achieving a learning rate of α = 0.25 and significant LCOE reductions from USD 0.02/kWh to USD 0.017/kWh. These findings emphasize the need for targeted TEA studies and strategic investments to unlock the full potential of MGTs in a decarbonized energy landscape. By leveraging learning and experience effects, stakeholders can predict cost trajectories more accurately and make informed investment decisions, positioning MGTs as a competitive and sustainable energy solution in the global energy transition.

Upgraded one-dimensional code for the design of a micro gas turbine mixed flow compressor stage with various crossover diffuser configurations

Abstract Micro Gas Turbine (MGT) designers often have the need for a design tool, capable of rapidly providing feasible design options. The upgrade of such an existing MATLAB® based mixed flow compressor design application (1D App) is discussed. In MGT engines, diffuser design largely influences the compressor stage performance. Crossover diffusers provide superior efficiency and pressure ratio performance compared to legacy type diffusers, albeit at the expense of operating range. The reduced operating range attributed to single vane crossover diffusers can be alleviated by splitter vane, tandem vane, and combined configurations. Therefore, the 1D App is updated to allow the user the ability to design these additional crossover diffuser configurations. Performance results are verified using Numeca/FINE™ Turbo CFD software. It is shown that the upgraded 1D App provides predicted performance results within 1 % of CFD results for both total-to-total efficiency and pressure ratio.

Experiment and dynamic simulation of micro gas turbine combined with concentrated solar power system

The solar micro gas turbine (SMGT) system is a promising solution to address the instability and intermittency of renewable energy sources. Its dynamic characteristics under unstable input conditions and uncertain output load demands are crucial for peak shaving. This paper constructs an SMGT system based on experiments with micro gas turbine (MGT) and concentrated solar power (CSP), analyzing the impact of integrating CSP system on the MGT. Then the performance of the SMGT under varying ambient conditions and load demands is studied. Results show that in grid-connected mode, the turbine speed of MGT and SMGT is determined by ambient temperature and set power, with electrical efficiency decreasing as temperature and DNI increase. The solar receiver in the SMGT should maximize temperature increase while maintaining pressure loss below 55 kPa. Additionally, a higher heat capacity can reduce sensitivity to ambient changes but also extends stabilization time. Under real solar radiation, the SMGT system can keep constant power within 0.6% fluctuation, with a solar share of 36.5%. When combined with photovoltaic, the hybrid system’s maximum power fluctuation does not exceed 2.6%, with a solar share of 48.8%. This study provides guidance for optimizing SMGT systems and their application in peak shaving scenarios.

Effects of inlet air holes on swirl flow characteristics and outlet temperature distribution in an axial swirl combustor

The air inlet holes on the swirl combustor are crucial for high-performance micro gas turbine (MGT), affecting internal airflow, fuel-air mixing, temperature distribution, and cooling. However, there are seldom studies that pay attention to the influence of the air inlet holes coupled with low volatility macromolecular fuels for fast and better fuel-air mixing and combustion processes in MGT. This study investigates the influence of primary and dilution hole positions on airflow, temperature, emissions, and combustion efficiency. Numerical simulations in ANSYS Fluent examine five inlet hole configurations in a two-stage axial swirl combustor. Simulation validation is conducted under three test conditions. The results showed that the cut-off effect of the primary hole affected the size of the swirl vortex core, and the backward movement of the primary hole resulted in a significant increase in the length of the recirculation zone and the coherence high-temperature zone, accelerated the droplet evaporation rate, and reduced CO and NO emissions. Backward movement of dilution hole alters flow field, affecting swirl vortex stability and reflow intensity. Case 3, with original dilution hole and backward extended primary hole, exhibits optimal outlet temperature distribution and combustion efficiency.

Renewable fuel-powered micro-gas turbine and hydrogen fuel cell systems: Exploring scenarios of technology, control, and operation

Two technology options, a proton exchange membrane (PEM) fuel cell and a recuperated micro-gas turbine (MGT) consisting of equipment with variable efficiencies and a controllable bypass valve, are modeled numerically. The validated simulations are studied under multiple scenarios, including technology, control, and operation. Under the technology scenario, the PEM fuel cell depicts higher net heat energy (1390.5 kW) with an overall efficiency of 93.27 %, significantly reducing thermal dissipation compared to the MGT, which has a low heat-to-power ratio (0.69) with the same hydrogen combustion rate (0.018 kg s−1). Following the fuel scenario, at 40 %-part load and 100 % bypass valve position, the highest net power (137.08 kW) and heat generation (635.07 kW) are achieved when 0.009 kg s−1 of hydrogen is combusted in MGT, exceeding other fuel utilization. In addition, the heating control strategy determines the availability status of the proposed technologies. The observed operational trends indicate effective fulfillment of urban heating needs by hydrogen combustion during Winter and Fall. However, the utilization of biogas leads to significant functional limitations. Finally, the operating function of the PEM fuel cell under off-design conditions is evaluated, resulting in notable enhancements in energy outputs and hydrogen consumption when considering the combination of control parameters compared to their individual evaluations.

On the Potential of Biomass-Fueled Externally Fired Micro-Gas Turbines in the Energy Transition: Off-Design Performance Analysis

Abstract The potential of replacing the use of natural gas with biomass gasification syngas through an externally fired micro-gas turbine (EFMGTs) is the main scope of this study. This includes the performance assessment at various off-design and ambient conditions compared to a reference natural-gas-fired Micro-Gas Turbine. The penetration of biomass use in the decentralized combined heat and power (CHP) sector can reduce fossil fuel dependency and contribute to the achievement of the net-zero emissions target. For this purpose, an analytical externally fired thermodynamic model is incorporated and validated with an artificial neural network (ANN) based on a natural-gas-fired micro-gas turbine unit. An operating strategy is proposed to ensure the system's safe operation under any fuel input conditions. The performance between the investigated cases is compared using an exergetic analysis. The main loss contributors that determine each case's performance are the exit losses. The substantial decrease of the latter results in high externally fired part-load efficiency, maximizing 110% of design-point efficiency. System performance has a linear dependency on ambient conditions. The increased flexibility introduced by the proposed operating strategy case facilitates the transition from natural gas to biomass, especially for higher heat-to-power ratio demands. The analysis highlights that the current externally fired configuration lags behind in high electrical demands (>90 kWel). However, this deficiency is diminished in cold ambient temperatures (<0 °C), indicating that the proposed technology is very opportune for these climatic conditions.

Isothermal turbines − New challenges. Numerical and experimental investigations into isothermal expansion in turbine power plants

The efficiency of power plants with steam or gas turbines depends on the efficiencies of a thermodynamic cycle and devices implementing this cycle. In the case of high power outputs, we cannot expect a significant increase in the efficiency of individual devices. Therefore, what remains is to increase the efficiency of the implemented thermodynamic cycle − the complex Rankine cycle in the case of steam turbines or the extended Brayton cycle in gas turbine units. The efficiencies of these cycles depend on the hot reservoir temperatures, limited by the materials used. The solution seems to be the thermodynamic cycles with the highest efficiency within given temperature limits, the „generalized Carnot cycles”. About gas turbines, such a cycle is the Ericsson cycle. The most difficult element of this cycle is carrying out high-temperature expansion. So far, there is no literature data on a technical device implementing this process. In this article, we present a method for designing turbine nozzles for isothermal expansion and the results of experimental tests of the first isothermal turbine. In the case of gas microturbines with a regenerator, isothermal expansion can increase efficiency from 24% to 28% up to 36%. An increase in efficiency of several to a dozen percentage points is expected for Organic Rankine Cycle (ORC) turbines. Due to such significant increases in energy generation efficiency, an isothermal turbine may become a future solution for energy systems.

ANALYSIS OF MICRO GAS TURBINE PERFORMANCE USING MODELLING APPROACH

Micro-gas turbine (MGT) is compact and self-sufficient distributed power generation units that exhibit reliability and has the capability to mitigate carbon monoxide (CO) emissions while conserving energy together with biomass used as a fuel sources. It is expected that they will have a noteworthy impact on securing the provision of upcoming energy resources for isolated areas, disaster condition and off-grid zone regardless of their connection to the power grid. However, the MGT performance using the various fuel still questionable. Databases and procedure of the MGT performance analysis should be established well to understand the overall MGT performance. In this study, MGT performance is determined by utilising the computer aided design (CAD) and solver software such as SOLIDWORKS and ANSYS-FLUENT. CAD drawing is used to design the combustion chamber and simulation performance is visualised in specific inside the combustion chamber (CC) of the MGT. The solver software was employed for the purpose of conducting computational fluid dynamics (CFD) analyses. The optimal configuration contained a flame holder with a diameter of 50 millimetres, a chamber height of 60 centimetres, four holes with diameters of 6, 8, and 10 millimetres, and a dead zone separating the combustion and dilution zones. The air inlet boundary conditions were established by utilising the specifications and compressor maps of the Garrett GT25 turbocharger in the simulation. The simulation employed the standard k-ε model of viscous model and energy equation to establish an optimal maximum airflow rate of 0.15 kg/s at a pressure of 1.4 bar, resulting in a compressor efficiency of approximately 70%. Three different fuels, diesel-air, wood-volatiles-air, and coal-hv-volatile, were used to determine the MGT's optimal performance. Successful investigation of this study opts to significant contribution to understand the MGT performance thus, give the awareness to choose as one of the alternative power generations which can be used in the future.

Upgrading the Compressor Stage of the CAT250TJ Micro Gas Turbine Engine

AbstractDue to their simplicity and relative ease of manufacture, single-stage centrifugal and mixed flow micro gas turbine (MGT) engines are preferred in thrust-based remotely piloted aerial vehicles. A single-stage mixed-flow compressor upgrade for the 200 N CAT250TJ MGT engine is numerically evaluated and presented. An in-house developed mean line application and commercial CFD software is used for the design and performance evaluation of the proposed upgrade configurations. The CAT250TJ – Gen1 engine features a single-stage centrifugal compressor, annular combustor, and single stage axial turbine. Apart from an upgraded impeller, a new crossover diffuser configuration is introduced to replace the wedge-type, straight outlet diffuser configuration of the Gen1 engine. The new single vane crossover diffuser configuration provides a design point total-to-total efficiency and pressure ratio increase of 8.3% and 12.1%, respectively. A disadvantage of a single-vaned crossover diffuser compared to legacy diffusers is a narrower operating range. To alleviate this issue, various combinations of tandem and splitter vane crossover diffuser configurations are proposed. These provide an enhanced operating range, comparable with the operating range displayed by the Gen1 configuration. A turbine power matching analysis is additionally completed to ensure proper compressor integration. Gas turbine cycle software is used to evaluate the on-engine performance of the upgraded compressor configurations. It is shown that the new baseline, single vane crossover diffuser configuration provides a 10.74% increase in design point static thrust.

Микрогазотурбинные установки с повышенными термодинамическими характеристиками

Конструирование микрогазотурбинных двигателей (МГТД) с повышенными термодинамическими характеристиками на единицу расхода рабочего тела является важной задачей транспортной, мобильной энергетики, а также теплоэлектроснабжения локальных и удаленных объектов. Одним из актуальных путей решения этой задачи является повышение энергоэффективности цикла. Предметом рассмотрения в статье является исследование влияния способов повышения энергоэффективности цикла на КПД и удельную мощность для различных базовых схем микрогазотурбинных установок (МГТУ). Рассмотрены следующие способы повышения энергоэффективности цикла: повышение максимальной температуры, промежуточный перегрев и двухступенчатое сжатие с промежуточным охлаждением. Применение всех модификаций позволило повысить удельную мощность базовых схем МГТУ в 2,0…2,7 раза. Показано, что, МГТУ, содержащие в составе и турбокомпрессорный утилизатор, и регенератор являются наиболее перспективными для любых модификаций. The design of micro-gas turbine engines (MGTE) with increased thermodynamic characteristics per unit of working fluid flow is an important task in transport and mobile energy, as well as heat and power supply of local and remote objects. One of the current ways to solve this problem is to increase the energy efficiency of the cycle. The subject of consideration in the article is the study of the influence of methods for increasing the energy efficiency of the cycle on the efficiency and specific power for various basic schemes of microgas turbine plants (MGTP). The following methods for increasing the energy efficiency of the cycle are considered: increasing the maximum temperature, reheat and two-stage compression with intercooling. The use of all modifications made it possible to increase the specific power of the basic circuits of the MGTP by 2.0...2.7 times. It has been shown that MGTPs containing both a turbocharge utilizer and a regenerator are the most promising for any modifications.

Optimal operating scenario and performance comparison of biomass-fueled externally-fired microturbine

This paper focuses on the determination of the optimal operating scenario of an Externally-Fired Micro-Gas turbine utilizing syngas produced by biomass gasification. Biomass exploitation can contribute to the achievement of the net-zero emissions target in 2050. This can be boosted by the advancement of externally-fired technology. In this study, a dual-objective optimization process, including a validated thermodynamic model, is combined with preliminary cost insights to assist the decision-making process. The resulting performance is compared with the actual data-based performance of a reference natural-gas-fired Micro-Gas Turbine. The performance comparison is performed through an exergetic analysis, identifying the main losses contributors. The optimization results in an externally-fired performance of 77.9 kWel electrical power and 20.3% efficiency, improved by 31.5% compared to the average current externally-fired demonstrated efficiencies. Yet, there is still room for improvement to reach natural-gas-fired Micro-Gas Turbine efficiency. The study highlights an unavoidable efficiency decrease of at least 4.0 percentage points due to the use of syngas itself instead of natural gas, which conversely increases heat recovery potential. However, compared to the state-of-the-art demonstrations, the proposed analysis is a significant step towards efficiency improvement, which can be exploited for future biomass demonstrations, attractive for electricity generation as well.

Impact of heat recovery and thermal load control on combined heat and power (CHP) performance

This research assesses the energy efficiency and techno-economic viability of a Combined Heat and Power (CHP) system designed for a typical building that meets both its electrical (97 kWh/d) and thermal (92 kWh/d) loads. The CHP system comprises wind turbines (WT), photovoltaic panels (PV), batteries, micro gas turbines (MGT), and boilers, which are evaluated for their techno-economic performance. To enhance the system's efficiency and minimize energy wastage in CHP, two strategies, namely heat recovery (HR) from MGT and Thermal Load Control (TLC) for converting surplus renewable power generation into thermal energy, are implemented. Four case studies are conducted to analyze the impact of each strategy on the CHP system's performance. The optimization of hybrid renewable energy systems, considering the overall system's economic performance, is achieved through the integration of MATLAB and HOMER PRO. The study reveals that the incorporation of TLC and HR results in significant reductions in the Cost of Energy (COE), Net Present Cost (NPC), CO2 emissions, loss of Power Supply (LPS), and energy sizing while increasing the renewable fraction in the CHP system. Sensitivity analysis is performed on the capital cost of components, TLC, and HR variations, demonstrating their substantial influence on the economic performance of CHP. The cash flow results show that the integration of these two components reduces the system cost by 25 %. It is also shown that almost 70 % of the CC of the system is related to PV and batteries. The proposed strategies and findings provide valuable insights for enhancing the reliability and techno-economic evaluations of hybrid renewable.

Optimal Economic Research of Microgrids Based on Multi-Strategy Integrated Sparrow Search Algorithm under Carbon Emission Constraints

In the global transition towards sustainable energy, microgrids are emerging as a core component of distributed energy systems and a pivotal technology driving this transformation. By integrating renewable energy sources such as solar and wind power, microgrids not only enhance energy efficiency and reduce reliance on traditional energy sources but also bolster grid stability and mitigate the risk of widespread power outages. Consequently, microgrids demonstrate significant potential in improving the reliability of power supply and facilitating flexibility in energy consumption. However, the operational planning and optimization of microgrids are faced with complex challenges characterized by multiple objectives and constraints, making the reduction in operational costs a focal point of research. This study fully considers an operational model for a microgrid that incorporates distributed energy resources and comprehensive costs, integrating a battery storage system to ensure three-phase balance. The microgrid model includes photovoltaic power generation, wind power generation, fuel cells, micro-gas turbines, energy storage systems, and loads. The objectives of operating and maintaining this microgrid primarily involve optimizing dispatch, energy consumption, and pollution emissions, aiming to reduce carbon emissions and minimize total costs. To achieve these goals, the study introduces a carbon emission constraint strategy and proposes an improved Multi-Strategy Integrated Sparrow Search Algorithm (MISSA). By applying the MISSA to solve the operational problems of the microgrid and comparing it with other algorithms, the results demonstrate the effectiveness of the carbon emission constraint strategy in the microgrid’s operation. Furthermore, the results prove that the MISSA can achieve the lowest comprehensive operational costs for the microgrid, confirming its effectiveness in addressing the operational challenges of the microgrid.

Exogenous-spatial scale techno-economic methodology for energy application assessment based on levelized cost of electricity: A case study in Norway

Amidst the escalating electricity prices in Norway and Europe, a compelling need arises for alternative and sustainable energy solutions. This study introduces a novel techno-economic method to assess micro-combined heat and power (m-CHP) systems, specifically those powered by Micro Gas Turbines (MGTs). Employing both numerical and experimental analyses, the investigation focuses on the techno-economic viability of MGT-based m-CHP systems fueled by natural gas (NG) and a blend of NG-H2 (23 % Vol.%). A 20-year operational lifespan serves as the basis for calculating the Levelized Cost of Electricity (LCoE) and comparing it with grid-based electricity costs. The technical model relies on 3 kW MGT experiments and numerical system modelling using IPSEPro® software. Economic modelling involves developing a cost model and employing a unique Techno Economic Analysis (TEA)-rooted methodology for LCoE calculation. Through 16 techno-economic scenarios, substantial cost-benefit advantages of m-CHP systems over grid-based electricity are demonstrated, supported by point LCoE values. To address uncertainties, a “Risk and Uncertainty” analysis is conducted using Monte-Carlo Simulation, generating a LCoE distribution. This method incorporates the standard deviations and mean values of key parameters, ensuring economic consistency and reliability with minimal fluctuations. Findings reveal negligible variation from the expected LCoE at 100 % power with NG, providing 98 % accuracy in assessing cost-benefit. The final result yields a Ceq, LCoE of 1.42 Current NOK/kWh (0.13 USD/kWh) and 1.19 constant NOK/kWh (0.11 USD/kWh). In contrast to grid electricity costs (2.54 NOK/kWh (0.24 USD/kWh) with current NOK and 1.78 NOK/kWh (0.17 USD/kWh) with constant NOK, the analysis underscores the significant and sustained cost benefits of m-CHP systems. Moreover, the proposed methodology offers flexibility for transitioning to a “carbon-neutral” operation with hydrogen (H2) as its prices decrease.

The effect of a tandem vane crossover diffuser configuration on the performance of a MGT mixed flow compressor

Due to the inherent geometric restrictions of a micro gas turbine (MGT) mixed flow compressor design, diffuser design has a major impact on compressor performance and operating range. Vaned diffusers are often preferred to vaneless diffusers in MGT compressor designs due to better efficiency and pressure recovery, albeit at the expense of operating range. A numeric investigation of the effect of a tandem vane crossover diffuser configuration on the performance and operating range of a MGT mixed flow compressor stage is presented. Three baseline test compressors, covering a wide range of design speeds, mass flow rates and meridional exit angles, are designed with a single vane crossover diffuser. For each of the three baseline compressors, the crossover diffuser design is modified to feature various tandem vane configurations. The tangential shift of the second vane row relative to the first row is evaluated. Additionally, relative first and second vane row lengths are evaluated. The performance (efficiency and pressure ratio) and operating range of the modified diffuser configurations are compared to the baseline configurations. It is shown that a 75% second vane row tangential shift configuration displays the best overall performance, regardless of the relative vane length. It is further shown that an appropriate vane length depends on the design requirement.

Supply and demand balance control strategy for microgrids considering uncertainty and disturbance based on online H∞ policy iteration

Abstract With the rapid growth of renewable energy generation, its proportion in power generation is increasing. Accompanied by this, due to the uncertain characteristics of renewable energy generation, the issue of imbalanced power supply and demand in microgrids has posed, which brings great challenges to the reliability of microgrid. In recent years, how to use energy storage system to solve this problem has become a hot research topic in microgrid. In this paper, an online H∞ policy iteration algorithm is proposed to control the output power of photovoltaic arrays and micro-gas turbines. At the same time, considering the uncertainty of the load demand in the microgrid system and the input disturbance of the micro gas turbine governor, the power supply and demand relationship of the microgrid can be balanced by the proposed control strategy. Finally, the effectiveness and practicality of the control strategy were demonstrated through simulation analysis.

An Artificial Neural Network-Based Fault Diagnostics Approach for Hydrogen-Fueled Micro Gas Turbines

The utilization of hydrogen fuel in gas turbines brings significant changes to the thermophysical properties of flue gas, including higher specific heat capacities and an enhanced steam content. Therefore, hydrogen-fueled gas turbines are susceptible to health degradation in the form of steam-induced corrosion and erosion in the hot gas path. In this context, the fault diagnosis of hydrogen-fueled gas turbines becomes indispensable. To the authors’ knowledge, there is a scarcity of fault diagnosis studies for retrofitted gas turbines considering hydrogen as a potential fuel. The present study, however, develops an artificial neural network (ANN)-based fault diagnosis model using the MATLAB environment. Prior to the fault detection, isolation, and identification modules, physics-based performance data of a 100 kW micro gas turbine (MGT) were synthesized using the GasTurb tool. An ANN-based classification algorithm showed a 96.2% classification accuracy for the fault detection and isolation. Moreover, the feedforward neural network-based regression algorithm showed quite good training, testing, and validation accuracies in terms of the root mean square error (RMSE). The study revealed that the presence of hydrogen-induced corrosion faults (both as a single corrosion fault or as simultaneous fouling and corrosion) led to false alarms, thereby prompting other incorrect faults during the fault detection and isolation modules. Additionally, the performance of the fault identification module for the hydrogen fuel scenario was found to be marginally lower than that of the natural gas case due to assumption of small magnitudes of faults arising from hydrogen-induced corrosion.

Cogeneration in electrical microgrids.

Simultaneous generation of electrical and useful thermal energy (hot, cold, or both) is an obvious way to optimize the consumed energy efficiency. In the last decade, cogeneration has had, in a world level, a big deployment, thanks to the use of gas and the fact of taking advantage of biomass and other waste products energetically valuable. However, there are possibilities to extend cogeneration applications by means of new technologies of multiple generation of: electrical power, heat, cold, desalination and/or regeneration of water and chemical products in general. The priority performances about this context are being centered in the development and researching of a distinguished group of electrical micro-generation technologies, which energetic benefits highlight because of a high global index of efficiency. In this group of advanced technologies Fuel Cells, Stirling Motor and Gas Microturbines are included.

DESIGN AND MULTI-PERSPECTIVE INVESTIGATIONS ON THE AERODYNAMIC PERFORMANCE FACTORS OF CONVENTIONAL AND ADVANCED UAV’S MICRO GAS-TURBINE ENGINE NOZZLES THROUGH VALIDATED CFD APPROACH

This paper describes the internal flow behaviors, aerodynamic performance effects, noise reduction techniques, and structural characteristic study on micro gas-turbine engine (MGTE) nozzles for small fixed-wing unmanned aerial vehicles (UAV). Firstly, the primary purpose is to obtain the aerodynamic performance, aeroacoustic, and structural parameters of the nozzle when applied to the MGTE. A baseline MGTE convergent nozzle is investigated on aeroacoustics and structural characteristics. Secondly, the baseline design is implemented with noise reducers, which include notches, a step-back airfoil, and nature-inspired notches. The notch initiates small disturbances on the surface of the jet plume and deforms the shear behind the nozzle, which in turn causes suppression in the jet mixing noise. Thirdly, the step-back airfoil is used in the nozzle's trailing end to optimize the flow at the exit. This causes turbulence and flow separation at the steps located at 50% of the chord length. Here, the step-back airfoil is done with a NACA0018-based configuration. Fourthly, nature-inspired notches impose computational performances on the aerodynamic factors, so the variations are noted. The notch, airfoil, and nature-inspired notch counts are increased and decreased to find the optimum model with minimal acoustic levels. The nozzle is modeled using CATIA and analyzed in the Ansys workbench. Furthermore, the model is tested through an advanced experiment facility and analyzed for pressure variations, velocity variations, and thermal variations by implementing numerous materials.

Thermodynamic investigation of an integrated near-zero CO2 emission power generation system with SOFC, MGT, SCO2BC, and CO2 capture

In response to the imperative to reduce carbon emissions in power generation, a novel near-zero CO2 emission power generation system integrating solid oxide fuel cell (SOFC), micro gas turbine (MGT), supercritical carbon dioxide recompression Brayton cycle (SCO2BC) and CO2 capture (CC) is proposed and investigated. The innovation lies in the utilization of oxy-combustion for CO2 capture from the anode off-gas and the strategic harnessing of waste heat from the cathode off-gas through sequential MGT and SCO2BC processes. A comprehensive mathematical model is developed to assess the thermodynamic performance of the integrated system. The results indicate that the electrical efficiencies of the individual components, SOFC, SOFC-MGT, and SCO2BC, are 56.52%, 66.00%, and 40.76%, respectively, and the integrated system demonstrates an impressive overall efficiency of 70.15% under a current density of 5000 A/m2. The efficiency penalty incurred by CC on the integrated system is approximately 2%. A sensitivity analysis of key parameters highlights the potential for optimizing individual components to enhance power output or efficiency. Notably, the optimal overall efficiency is achieved when the SOFC operates at 0.25 MPa, the fuel utilization ratio is 85%, and the SCO2BC compressor pressure ratio is 2.6. This research not only establishes the viability of the proposed integrated system but also provides insights into optimizing its components for improved performance in power output and efficiency.