Micro Gas Turbine Research Articles

CFD study case of ammonia-hydrogen mixture powered methane gas microturbine combustor in the context of the temperature repartition modifications

Actually many research are conducted on the ability of hydrogen-ammonia mixture fuel to replace classical fuel such as methane for gas (micro)turbine use. These studies concern the combustion stability and NOx formation. Temperature repartition in gas (micro)turbine combustor is very important from a thermomechanical point of view. This issue is often omitted in research. If modifications occur in temperature repartition, an overheating zone can appear and lead to mechanical damage of the combustor liner. Numerical studies, CFD method based with the use of Ansys Fluent tools, were conducted on a self-designed gas microturbine combustor, for methane application, using various ammonia-hydrogen mixtures and methane fuelling. Then, the obtained temperature maps were compared between methane and ammonia-hydrogen mixtures with various compositions to find an ammonia-hydrogen mixture composition that permits to reproduce a similar temperature repartition as for methane fuelling; this mixture contains maximally 10%mass hydrogen (or 48%vol). This ammonia-hydrogen mixture composition was compared to others research where the ammonia-hydrogen composition was optimised for combustion stability and NOx reduction (hydrogen content of 30%vol). According to performed studies, the proposed ammonia-hydrogen composition in others research is confirmed to be safe for gas microturbine applications from a thermomechanical point of view.

Technologies for capturing and storing carbon dioxide during conversion, use of fuel and gaseous waste from energy production

Relevance. The continued dependence on the combustion of carbon-based fuels for energy and industry leads to the need to develop various categories of technologies to reduce carbon dioxide emissions. Aim. Development of carbon capture and storage technologies for all stages of fuel conversion and processing, ensuring a low-carbon cycle for the production of electrical and thermal energy, as well as industrial and social facilities. Methods. Chemical, physical adsorption and absorption. Results and conclusions. For large industrial and energy producers, for small energy consumers, it is necessary to be guided by the principles of environmental friendliness and efficiency when implementing the production process, and to increase the percentage of carbon dioxide removal, implement decarbonization technologies at all stages of producing electricity and thermal energy. For the category of CO2 removal at the stage of preliminary fuel conversion, adsorbent compositions using predominantly environmentally friendly and inexpensive natural materials based on bentonite have been developed and tested. The collection capacity of the developed adsorbents is 85–98%. For the category of CO2 removal at the stage of fuel use, a hybrid energy system is presented, including a microgas turbine with heat recovery, a high-temperature fuel cell and other devices and material flows connecting them. A pilot industrial prototype of a 30 kW hybrid energy system will produce heat, electricity, steam, and hot water. In this embodiment, the hybrid system can work as an autonomous energy source for small social and commercial facilities, representing a pilot stage of the engineering and design implementation of the results of an industrial-level hybrid system. For the category of carbon dioxide removal at the stage of CO2 separation from the flue gas mixture after fuel conversion, a block for removing CO2 from flue gases using the absorption method was proposed. Solutions of 15% monoethanolamine, 15% ammonia solution, and 6% sodium hydroxide solution showed the best absorption capacity. It is proposed to equip the hybrid energy system with a CO2 capture unit for complete decarbonization of gas emissions based on closed-cycle technology. The proposed technology for capturing and storing carbon dioxide at the post-fuel conversion stage is characterized by ease of implementation and economic accessibility.

Numerical study of the influence of flow control methods on the efficiency of a micro-gas turbine

This paper presents innovative solutions to enhance the aerodynamic performance of the radial turbine and the efficiency of the Capstone C30 micro-gas turbine unit (micro-GTU) through the integration of a cycle air cooling system and advanced flow control mechanisms. The study investigates various flow control methods within the blade channels of the radial turbine, including splitters, triangular root fins, and inter-tier partitions. The results show that using splitters with a relative length of 0.7 increases internal relative efficiency from 80.9% to 81.75%, implementing triangular root fins enhances efficiency from 80.9% to 81.44%, and adding an inter-tier partition improves internal relative efficiency from 80.9% to 81.7%. A finned turbine configuration with splitters of relative length 0.7 achieves the highest internal relative efficiency of 82.2%. These advancements contribute to improved turbine performance and efficiency, addressing the need for enhanced domestic energy solutions in the context of distributed energy generation in Russia.

CFD modelling of micro turbomachinery blade: integrating surface roughness with novel reverse-engineering strategies

Abstract This paper presents the results of reverse-engineering (RE) strategies, surface roughness and computational fluid dynamics (CFD) modelling for a Wren100 micro gas turbine (MGT). Utilising silicone moulds and resin tooling, precise blade geometry capture was achieved for 3D reconstruction allowing for discrete and parametric geometric models to be created. Using these geometries, CFD simulations employing both Reynolds-averaged Navier–Stokes (RANS) and large eddy simulation (LES) models, alongside experimental wind tunnel cascade tests, were used to evaluate these reverse engineering strategies. The results show that while the parametric model captures overall MGT performance with fewer parameters, the discrete model provides enhanced accuracy, highlighting its suitability for detailed aerodynamic analyses. Contrary to initial expectations, surface roughness exhibited a noticeable impact on performance despite the lower Reynolds numbers (40,000), as demonstrated by the CFD model and wind tunnel experiments. The results indicate that surface roughness can reduce laminar separation bubbles on the blade leading edge, delay the onset of transition, and mitigate secondary flow losses. Overall, this study contributes to knowledge advancement in turbine blade reverse engineering and aerodynamics by detailing the impact of surface roughness on performance.

An Innovative Online Adaptive High-Efficiency Controller for Micro Gas Turbine: Design and Simulation Validation

In this article, an innovative online adaptive high-efficiency control strategy is proposed to improve the power generation efficiency of a marine micro gas turbine under partial load. Firstly, a mathematical model of the micro-gas turbine is established, and a control strategy consisting of an on-board prediction model and an online update model is proposed. To evaluate the performance changes of the gas turbine, we applied deep learning techniques to enhance the extreme learning machine (ELM) algorithm, resulting in the development of a high-precision, high-real-time deep extreme learning machine (DL_ELM) prediction model. This model effectively monitors changes in the gas turbine’s performance. Furthermore, an online time-series deep extreme learning machine with a dynamic forgetting factor (DFF_DL_OSELM) model is designed to achieve the real-time tracking of performance variations. When the DL_ELM model detects a gas turbine’s performance change, a particle swarm optimization (PSO) algorithm is employed to iteratively calculate the DFF_DL_OSELM model, determining the optimal speed control scheme to ensure the gas turbine operates at maximum efficiency. To validate the superiority of the proposed control strategy, a comparison is made with traditional high-efficiency control strategies based on polynomial fitting and BP neural networks. The results demonstrate that although all three strategies can achieve efficient operation under constant conditions, traditional strategies fail to identify and adjust to performance changes in real time, leading to decreased control performance and potential engine damage as engine characteristics degrade. In contrast, the proposed online adaptive control strategy dynamically adjusts the speed control plan based on performance degradation, ensuring that the gas turbine operates efficiently while keeping the turbine inlet and exhaust temperatures within safe limits.

Performance analysis and optimization of a combined cooling, heating and power system based on active regulation of thermal energy storage

The energy storage unit can significantly address the issue of mismatch between the energy supply and demand of the combined cooling, heating and power (CCHP) system. Therefore, this article proposes a micro-gas turbine coupled with low-concentrating photovoltaic/thermal CCHP system with thermal energy storage active regulation, which can change the thermoelectric output ratio of the micro-gas turbine. The impact of the volume of the heat storage tank and the changes in ambient temperature on the system's performance is analyzed. This system is optimized with the objective functions of primary energy consumption saving rate, carbon dioxide emission reduction rate, total annual cost saving rate and exergy efficiency maximization. The results indicate that increasing the volume of the thermal energy storage tank enhances the exergy efficiency. Furthermore, an increase in ambient temperature can improve the objective functions. The optimum comprehensive performance of this system is achieved when the thermal energy storage tank volume is 40 m³ and the gas boiler capacity is 241.16 kW. With the thermal energy storage active regulation, the primary energy consumption, carbon dioxide emissions and annual total cost of the system decline by 2.24 %, 2.12 % and 1.48 %, and the system exergy efficiency improves by 1.72 %.

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.

Techno-economic optimization of microgrid operation with integration of renewable energy, hydrogen storage, and micro gas turbine

Microgrids are integral to modern energy systems, yet they face substantial challenges in integrating diverse components, managing complex dynamics, and ensuring stability amid renewable energy variability. This study investigates the integration of wind turbines, an electrolyzer, and a hydrogen-compatible micro gas turbine (MGT), with a focus on enhancing operational efficiency and maintaining dynamic equilibrium within the microgrid. The synergy between the electrolyzer and MGT provides a robust energy storage solution, improving both system stability and performance.Using advanced machine learning and real operational data, this research generates highly accurate, rapid models with greater precision and detail than conventional methods. The intelligent management system developed combines real-time optimization and adaptive fine-tuning, using forecasts of weather, electricity prices, and energy demand to devise optimized operational strategies. The study systematically analyzes various configurations, including grid-connected and island modes, and evaluates the impact of hydrogen storage in each scenario.The results demonstrate that the optimization approach substantially enhances economic returns. However, this can also lead to increased natural gas consumption and emissions, revealing a trade-off between financial gains and environmental sustainability. This highlights the necessity for strategies that reconcile economic incentives with sustainability objectives, offering valuable insights for improved microgrid management.

Evaluation of the Interconnection of a Biomethane Microturbine in an Absorption Refrigeration System

This article evaluates the performance and environmental impact of a combined system of natural gas microturbine and absorption refrigeration system. The objective of the study is to evaluate the interconnection of a biomethane microturbine in an absorption refrigeration system. The study applies energy and exergy balances to each component of the system, using EES software for the simulation. The microturbine is a Capstone C600s model with a nominal power of 600 kW, and the absorption chiller is a single-stage LiBr-H2O system with a cooling capacity of 680.7 kW. The results show that the microturbine achieves a thermal efficiency of 34%, an exergetic efficiency of 86%, and a net power output of 585.4 kW. At the same time the absorption chiller has a coefficient of performance (COP) of 0.7 and 680.7 kW with generator water temperature inlet of 100 °C. On the other hand, this study identifies the most efficient points of interconnection between the two systems. The combined system reduces the CO2 equivalent emissions by 700 to 900 tons/year compared to conventional systems. The behaviour of the interconnection heat exchanger is also evaluated using Computed Fluid Dynamics. The investigation concludes that the interconnection of a natural gas microturbine and an absorption refrigeration system is a promising alternative that can optimize both technical and economic aspects of energy generation and utilization, while mitigating environmental problems.

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.

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.

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.