Micro Gas Turbine Research Articles

Distributed Generation of Energy Using Micro Gas Turbines. Polygeneration Systems and Fuel Flexibility.

The use of micro gas turbines (MGT) for on-sitesmall-scale energy production offers a great opportunity forprimary energy saving and reduction of pollutant andgreenhouse gas emissions. These benefits mainly come from thepossibility to locally recover waste heat from exhaust gasespecially for air conditioning thermally activated technologlesand also for their capability to use low heating value gases suchdigester gas. This paper summarises the potential of' micro gas turbines indistributed generation systems to simultaneously producepower, heat and chilled water for air conditioning. Differentconfigurations for coupling micro gas turbines and sorptionsystems will be presented from the conventional hot waterdriven to the directly exhaust gas driven configurations. Themain advantage of these systems is the consumption of wasteheat for refrigeration and air conditioning instead of high costelectricity. On the other hand the use of digester and landfill gas in microgas turbines is very attractive from many points of' view:reduced electrical bill, higher energy efficiency due to on-siteheat recovery, reduction of odours and lower greenhouseemissions. The processing of pig manure to produce biogas isof high interest in geographic areas with a surplus of manurethat can not be naturally absorbed and limits the growth of farmsites. In this paper it is presented a summary of' the state of' theart for the use of biogas in microturbine based cogenerationsystems along with a brief description of the different types offuels that can also be used in microturbines.

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.

Numerical Study of the Influence of Different Bending Shapes on the Heat Transfer Characteristics of Annular Cross Wavy Primary Surface Recuperator (CW-PSR)

The cross-wave primary surface recuperator (CW-PSR) is a dependable option as a recuperator for micro gas turbines (MGT). The micro CW-PSR studied in this paper is composed of 171 stacked curved plates, with each plate containing 33 micro heat transfer channels with equivalent diameters of less than 1 mm. In this study, the influence of bending curvature on the thermal performance of CW-PSR plates is investigated through three-dimensional numerical simulation with fluid–solid–thermal coupling. The results indicate that the variation in bending curvature studied can result in a noteworthy 8% difference in the total heat transfer coefficient of CW-PSR plates. A direct correlation between heat transfer capacity and secondary flow strength is derived mathematically, explaining the mechanism by which secondary flow enhances heat transfer. By employing this relationship, a comprehensive analysis of CW-PSR plates with diverse bending curvatures is conducted, effectively showcasing how curvature influences the secondary flow pattern and enhances the channel’s heat transfer capacity. In addition, this paper considers the comprehensive influence of the size parameters of the heat transfer unit and the bending curvature of the heat transfer plate on the heat transfer and flow characteristics of the CW-PSR, and a dominant mathematical expression is obtained, which can be used for the design of similar heat exchangers of the same type.

A Distributed Dispatch Method for Power Distribution Networks Considering Large-scale Connected Electric Vehicles

The connection of large-scale electric vehicles (EVs) to power distribution networks leads to challenges such as increased peak loads and communication difficulty. To address this challenge, in this paper, a distributed dispatch method is suggested for power distribution networks that take the connection of large-scale EVs into account. First, a distributed dispatch framework is developed for the power distribution network. Subsequently, resources such as EVs, distributed photovoltaics (PVs), and micro gas turbines (MGTs) are considered to construct an optimal dispatch model, and the alternating direction multipliers method (ADMM) is applied to achieve a distributed solution. Finally, the performance of the suggested approach is tested on a modified IEEE 33-bus model.

Direct Numerical Simulation of a Reacting Turbulent Hydrogen/Ammonia/Nitrogen Jet in an Air Crossflow at 5 Bar

The article aims to analyze the fluid dynamics and combustion characteristics of a non-premixed flame burning a fuel mixture derived from ammonia partial decomposition injected in an air crossflow. Nominal pressure (5 bar) and inlet air temperature (750 K) conditions are typical of micro-gas turbines. The effects of strain on the maximum flame temperature and NO generation in laminar non-premixed counter-flow flames are initially explored. Then, the whole three-dimensional fluid dynamic problem is investigated by setting up a numerical experiment: it consists of a Direct Numerical Simulation, based on accurate transport, chemical, and numerical models. The flow topology of the specific reacting jet in crossflow configuration is described in terms of its main turbulent structures, like shear layers, ring, and horse-shoe vortices, as well as of its leeward recirculation region anchoring the flame. The reacting region is characterized by providing instantaneous spatial distributions of temperature, heat release, and some transported chemical species, including NO, and calculating the Flame Index to identify non-premixed and premixed combustion local conditions. The latter is quantified by looking at the distribution of the volume fraction associated with a certain Flame Index versus the Flame Index and at the distribution of the average values of both the Heat Release Rate and NO versus the Flame Index and the mixture fraction.

Multi-objective optimization of micro-gas turbine coupled with LCPV/T combined cooling, heating and power (CCHP) system based on following electric load strategy

A distributed energy system integrated with solar and natural gas can achieve cascade energy utilization, high efficiency and energy-saving, and significantly reduce carbon emissions, which is receiving increasing attention. Therefore, this paper establishes an optimization model for primary energy consumption saving rate (PECSR), annual total cost saving rate (ATCSR), carbon dioxide emission reduction rate (CDERR) and exergy efficiency of micro-gas turbine coupled with low-concentrating photovoltaic/thermal (LCPV/T) CCHP system, and analyzes the influence of the parameters, such as solar irradiation, LCPV/T inlet temperature, LCPV/T inlet flow, LCPV/T area, low-temperature water source heat pump capacity, high-temperature water source heat pump capacity, the heat transfer efficiency of waste heat recovery boiler (WHRB) and gas boiler capacity, on the objective functions. The analysis results indicate that when the heat exchange efficiency of WHRB reaches 0.71, the CCHP system is most economical. Based on this, the Strength Pareto Evolutionary Algorithm-II (SPEA-II) optimization algorithm and decision-making method combining Technique for order preference by similarity to an ideal solution (TOPSIS) and weight entropy method are employed to solve the model comprehensively, and acquire the optimum solution. After multi-objective optimization and selection, the system exergy efficiency remains around 25 %. Compared with the separation production system, the PECSR and CDERR of the CCHP system are improved by more than 24 % and 41 %, respectively.

Chance constrained robust hydrogen storage management to service restoration in microgrids considering the methanation process model

After a natural disaster, electrical grids might go into a self-healing mode to restore service and reconnect any customers that lost power. In the self-heal system, the fast operation and restoring the critical loads (CLs) during a fault by available resources can increase the flexibility and resilience of the network. In addition to renewable energy sources and electric vehicles (EVs) storage devices, the hydrogen storage system and the process of converting hydrogen into electric energy by micro-gas turbine (MGT) have been modeled in order to assess the impact of this storage system in electrical loads restoration in critical conditions. Self-healing functionality is enhanced by using alternative and novel energy sources. In such a situation, how to interact with the stochastic nature of network components will be challenging. This paper formulates the optimal service restoration (SR) problem using chance-constrained Adaptive Distributionally Robust Optimization (ADRO) to address the ambiguities introduced by the uncertain parameters. A tri-level robust optimization model is developed such that the optimal switching in the network until clearing the fault is determined at the upper level, and the maximization of the SR based on the load demand values is determined at the lower level. The proposed method is demonstrated by simulation results on the modified Civanlar test system. In an equal operating condition and considering β = 3, it can be seen that the initial hydrogen State of the Tank (SoT) by 50 % can improve the load restoration by 7.5 % compared to the uncharged hydrogen tank. By increasing the initial SoT to the nominal value (10 Kg), the load restoration can increase to 13.2 %.

Micro Combined Heat and Power (micro-CHP) Systems for Household Applications: Techno-economic and Risk Assessment of The Main Prime Movers

ABSTRACT To limit global warming and meet international environmental targets, more environmentally benign technologies must be used in the residential market. Combined Heat and Power (CHP) at the micro-scale (<50 kWe) is seen as one of the best solutions that offers simultaneous generation of both electricity and heat with high overall efficiencies using environmentally friendly fuels (e.g., biofuel, hydrogen, syngas). In this study, four major micro-CHP prime movers (i.e. Micro-gas turbine, Gas engine, Stirling engine, and Fuel cell) have been evaluated in terms of their performance and the currently available technologies and products. The most suitable options for household applications were identified using Political, Economic, Social, Technological, Legal, and Environmental (PESTLE) risk analysis and a Multi-Criteria Decision Analysis (MCDA). Fuel cells display the best environmentally friendly properties despite their price and high start-up time. Gas engines (Reciprocating engines) have the most developed technology with the fastest start-up time and high efficiencies but have vibration and noise issues. Micro-gas turbine micro-CHPs are emerging into the market with relatively cheaper prices, lower maintenance, and good start-up time. Stirling engines are fuel flexible with reasonable prices and available products. Micro-CHP systems, particularly when running on biofuels and hydrogen, provide excellent energy solutions for the future net zero buildings.

Design and Thermo-Economic Analysis of an Integrated Solar Field Micro Gas Turbine Biomass Gasifier and Organic Rankine Cycle System

A micro gas turbine (MGT) is an advanced technology with a simple structure and fast load response. It represents a good choice for the next generation of distributed power systems, where fossil fuels are going to be largely replaced by biofuels and renewable sources. In this context, this work aims to investigate and compare the performance of gradually more complex energy systems integrating a micro gas turbine plant: simple cogenerating asset, integrating a solar field, presence of a gasifier, and the addition of a bottoming ORC. In all cases, a thermo-economic analysis has been carried out for an application in the agricultural sector. Agricultural waste can be used to create a syngas as fuel for MGT through a gasifier, promoting the utilization of carbon-neutral alternative fuels to reduce harmful emissions. The authors considered the electrical and thermal needs of a hypothetical agri-food company to build the electrical and thermal load curves. The new and more complex cogeneration plant, designed by using the Thermoflex 30 software, leads to an increase in electrical power, recovered thermal power, overall electrical efficiency, carbon neutrality, and cogeneration indexes. In particular, the presence of the solar field promotes a reduction in fuel consumption as well as greater heat input to the thermal unit. The addition of a bottoming ORC system increases the electrical power by 36.4%, without significantly penalizing the thermal unit. Moreover, thanks to the gasifier that offsets the fuel reduction costs, through an economic analysis of the entire plant, a payback time of the investment of less than 4 years is obtained.

Hybrid energy storage power allocation strategy based on parameter-optimized VMD algorithm for marine micro gas turbine power system

The power system onboard ships is typically a low-inertia, small-capacity isolated grid that is highly susceptible to system disturbances and instability, especially when connected to high power pulse loads. To mitigate power fluctuations and ensure stable operation, a hybrid energy storage system (HESS), which comprises the battery system and flywheel energy storage devices, has emerged as a promising solution. This paper explores the control strategy and coordinated operation of marine gas turbine power generation systems operating under pulse load conditions and presents a novel hybrid energy storage power allocation strategy based on variational mode decomposition (VMD). Specifically, we propose to implement parameter optimization of VMD using an artificial hummingbird algorithm (AHA), which enables effective primary allocation of hybrid energy storage power. To achieve secondary power allocation, we design two fuzzy controllers to optimize the state of charge (SOC) of battery system and speed of flywheel device. To evaluate the feasibility and effectiveness of the proposed control strategy, we establish a theoretical model of a shipboard micro gas turbine (MGT) direct current (DC) power system, which includes an MGT, generator, HESS, and pulse power load. Our simulation results demonstrate that the artificial hummingbird algorithm outperforms the particle swarm algorithm concerning search speed and calculation accuracy for parameter optimization of variational mode decomposition. Moreover, the proposed parameter-optimized VMD method can adaptively decompose pulse load power fluctuations and achieve optimal allocation of the flywheel and battery power in the HESS. Finally, the parallel fuzzy controller design effectively optimizes the operation ranges of the flywheel device and battery system, prevents over-charging and over-discharging of energy storage equipment, ensures that the SOC of energy storage equipment remains within a fixed interval, and reduces frequent and high-power charging and discharging of batteries.

Bellman–Genetic Hybrid Algorithm Optimization in Rural Area Microgrids

Incorporating renewable Distributed Energy Resources (DER) into the main grid is crucial for achieving a sustainable transition from fossil fuels. However, this generation system is complicated by the fluctuating behavior of renewable resources and the variable load demand, making it less reliable without a suitable energy storage system (ESS). This study proposes an Optimal Power Flow Management (OPFM) strategy for a grid-connected hybrid Micro Grid (MG) comprising a wind turbine (WT), a photovoltaic (PV) field, a storage battery, and a Micro Gas turbine (MGT). This proposed strategy includes (i) minimizing the MG’s daily energy cost, (ii) decreasing CO2 emissions by considering the variable load, weather forecast, and main grid fees to optimize the battery charging/discharging strategy, and (iii) optimizing the decision-making process for power purchase/sell from/to the main grid. The suggested OPFM approach is implemented using a Genetic Algorithm and compared with the Bellman Algorithm and a restricted management system via several simulations under the Matlab environment. Furthermore, the hybridization of the Bellman Algorithm and the Genetic Algorithm is proposed to enhance the OPFMC strategy’s efficiency by leveraging both algorithms’ strengths. The simulation results demonstrate the effectiveness of the proposed strategy in lowering energy costs and CO2 emissions and enhancing reliability. Additionally, the comparison of the hybridized GA algorithm reveals a cost 16% higher than the Bellman Algorithm; however, the use of the hybridized GA algorithm leads to a reduction in GHG emissions by 31.4%. These findings underscore the trade-off between cost and environmental impact in the context of algorithmic optimization for microgrid energy management.

Энергетический комплекс на базе высокооборотной электрической машины

Purpose: The purpose of this study is to develop the scientific basis for designing high-speed electric generators used in conjunction with gas micro-turbines. Methods: To solve the tasks set, the theories of electrical machines; the finite element method; automatic control theory; methods of mathematical analysis, mathematical and circuit modeling; numerical modeling on a PC using FEMM and Matlab Simulink software complexes have been used. The research has been carried out on experimental samples of a high-speed electric generator and confirmed by the results of tests as part of an energy complex based on a gas microturbine in 2019. Results: A complex of scientifically based technical solutions for the design of a high-speed electric generator with an energy complex control system based on a micro-gas turbine has been developed. As a result, a high-speed electric generator for a gas microturbine with a power of 100 kW and a rotation speed of 100,000 rpm has been developed and manufactured. When designing, an asynchronous type electric generator with a massive rotor has been selected. A feature of the developed design is the use of a five-phase stator winding. A control system of an experimental sample of a high-speed electric generator for micro-GTU has been developed. Practical significance: It lies in the development of methods and algorithms for designing high-speed generator equipment for micro-GTU. Recommendations have been developed for choosing the type and configuration of a high-speed electric generator for an electric complex based on a micro-gas turbine. A method is proposed for calculating the parameters of the substitution circuit of a highspeed electric generator, which allows us to determine the parameters of the substitution circuit according to the known configuration of the active layer at the design stage.

Computational Fluid Dynamics (CFD) Assessment of the Internal Flue Gases Recirculation (IFGR) Applied to Gas Microturbine in the Context of More Hydrogen-Enriched Fuel Use

Renewable energy is a promising substitute for fossil fuels when corelated with P2G technology. To optimise P2G efficiency, there is a need to increase hydrogen fraction in the fuel stream. Simultaneously gas microturbines are widely applied in many industry sectors. These devices are often equipped with diffusion combustors. This situation was investigated in this paper. The P2G and gas microturbines may be integrated together in the future leading to the application of hydrogen-enriched fuel. Hydrogen-enriched fuel causes increase in combustion temperature and velocity. In a nonadapted combustor, these phenomena could result in an increase of NOx emissions and risk of material overheating and failure. In order to adapt the combustors for hydrogen-enriched fuel, the concept of autonomous internal flue gases recirculation (IFGR) system was applied to this issue. In this paper, the IFGR system applied to gas microturbine was studied in terms of hydrogen-enriched fuel application. The obtained exhaust gases recirculation ratios were too low to affect the combustion process as it was expected. The observed combustion modifications in the combustor were hardly linked to the air flow modification in the liner, due to IFGR system implementation. After CFD studies, the proposed IFGR system does not seem to provide the expected effects.

Optimum Design, Socioenvironmental Impact, and Exergy Analysis of a Solar and Rice Husk-Based Off-Grid Hybrid Renewable Energy System

This study examines the optimal sizing of an off-grid hybrid system comprising solar photovoltaic (PV), rice husk-based biomass, and lead-acid battery for meeting the electric demand of a rural community. Considering a selected remote village in Bangladesh as a case study, the proposed optimized system is primarily compared with the diesel generator and the micro gas turbine (MGT)-based options in techno-economic and environmental terms. The potential social benefits, such as the employment creation and the improvement in the human development index in the locality, have been investigated in this study. Moreover, the impacts of operational greenhouse gas emissions on the human health damage and the surrounding ecosystem have been examined. Additionally, an exergy analysis of the hybrid system and the components has been carried out. Results indicate that in addition to being the environmentally preferable option, the proposed PV/biomass/battery system offers a lower cost of energy of 0.314 $/kWh compared to the MGT-based system (0.377 $/kWh). Although the diesel-based system offers a marginally better economy (9.55% less energy cost), it comes with the expense of probable damages to human health and the ecosystem worth of $15,211 and $6,608, respectively, making biomass the best option with no such damages. Exergy analysis reveals higher loss from PV than biomass and 13.09% system exergy efficiency. The assessment of the social indicators testifies to the potential of promoting the human development index from its current value and the formation of 1.41 jobs to as high as 15.15 full-time permanent jobs with the installation of hybrid systems in the community.

Chlorella vulgaris microalgae derived blends in micro gas turbine engines: A comprehensive environmental impact analysis for highway vehicle applications

The significant benefits of microalgae biofuel have made it a preferred choice in various industries, including aviation. Microgas turbine engines can be promising choice for highway vehicles. This research paper investigates the process of producing fuel from microalgae, as well as its performance and emission characteristics in the micro gas turbine engine operating at sea level conditions for highway vehicle applications. A two-step extraction and transesterification process were employed to convert the biofuel, using a batch stirrer reactor for esterification. The preparation of biofuel blends followed the volume fraction method at the concentration of 10% and 30%. Additionally, nanoparticles were incorporated into the blends at a 50 ppm concentration to enhance overall characteristics of the engine. Titanium dioxide nanoparticles, known for their high surface-to-volume ratio, were used for this purpose. Experimental tests were conducted on a 30 kW micro gas turbine engine to evaluate the fuel's quality in terms of performance and emissions. Various parameters were measured at different engine speed, including 30,000 rpm, 40,000 rpm, 50,000 rpm, 60,000 rpm, and 70,000 rpm. The results obtained clearly demonstrate that the optimal blending of biofuel with neat Jet-A fuel improves performance by generating the required thrust while significantly reducing harmful gas emissions. Furthermore, the addition of nanoparticles acted as a catalyst and enhanced the quality of the fuel blends, making them an efficient alternative for aircraft engines as well. Added to above, there is an significant reduction in the emission of the CO has been noted across wide range of speed. From the results it is evident that microgas turbine engine can be an ideal choice for the highway vehicles to meet reduced carbon emissions.

Evaluation of engine characteristics of a micro-gas turbine powered with JETA1 fuel mixed with Afzelia biodiesel and dimethyl ether (DME)

The use of Jet fuels in micro gas turbines results in high fuel consumption and increased gaseous emissions which in turn causes environmental pollution. In this study, a fixed proportion of Afzelia-Africana biodiesel (A) was mixed with dimethyl-ether (B) and Jet A1 (J) fuel of varying proportions, A10B10J80 (10% biodiesel, 10% dimethyl-ether, 80% Jet fuel), A10B15J75 (10% biodiesel, 15% dimethyl-ether, 75% Jet fuel), and A10B20J70 (10% biodiesel, 20% dimethyl-ether, 70% Jet fuel) in a bid to produce a fuel of improved properties. Their properties were compared with those of their pristine forms by testing the fuels in the gas turbine in order to ascertain the resulting engine emissions, thrust and thrust specific fuel consumption. Compared to the JETA1 fuel, the A10B10J80 fuel gave the best results in terms of engine speed, thrust (37 N) and thrust specific fuel consumption (4.3/h vs 5/h); the CO2, NOx, and CO emissions were lower for the blended fuels compared to those of the JET fuel. The A10B15J75 and A10B20J70 fuels gave 3 and 4.5% lower thrusts respectively, while the A10B10J80 fuel gave 3% increase in static thrust with a 14% reduction in its thrust-specific fuel consumption over the JET A1 fuel.

Development of a new hybrid energy system based on a microturbine and parabolic trough collector for usage in sports stadiums

The use of solar technologies is expanding day by day due to easy access and its easiness in combining with other systems. The low density of solar radiation in some places has caused a quiet acceptance of this type of energy, which can be overcome by concentrating solar radiation in a specific area. One of the other problems of renewable energy is the lack of access at all hours of the day and night, and to solve this problem, a gas microturbine system has been used. The purpose of this research is to supply the thermal and electrical energy needed by the sports stadium. The purpose of this research is to investigate the hybrid gas microturbine system with a capacity of 30 kW with a linear parabolic concentrator collector. To achieve this goal, thermodynamic modeling was done and the effect of effective parameters on electrical and thermal power production was evaluated. Among the significant results of this research, the decrease of 0.1% in mechanical power due to the increase of 5 °C in the ambient temperature is noticeable, and on the other hand, according to the obtained results, it can be said that the electrical and mechanical efficiencies increase by 3% due to the increase in the annual radiation intensity to the amount of 1100 W/m2.

Thermodynamic and economic analysis of a multi-energy complementary distributed CCHP system coupled with solar thermochemistry and active energy storage regulation process

The combination of distributed energy systems (DES) and solar energy is considered a vital measure to save the usage of fossil energy. A new distributed combined cooling, heating and power (CCHP) system integrated with solar thermochemistry (STC) and energy storage (ES) units is proposed. The methane steam reforming (MSR) reaction is driven by solar energy to produce hydrogen-rich syngas, which is fed with high-efficiency solid oxide fuel cell (SOFC) – micro gas turbine (MGT) to produce electricity. The residual heat of the flue gas drives a double effect lithium bromide unit for cooling and a heat exchanger for heating, while a parabolic trough collector (PTC) is used to supplement cooling and heating supply. Under different weather conditions and user load demands, simulation analysis of the matching between system outputs and user loads is conducted, and the thermodynamic and economic performance are analyzed. The results show that through active energy storage regulation, the new system outputs can meet the hourly user loads with a matching degree of 1. The total exergy efficiencies of the system on typical summer, transition and winter days are 69.93%, 62.03%, and 52.28%, respectively, and the specific CO2 emission rates are 152.57 g/kWh, 191.75 g/kWh, and 234.16 g/kWh, respectively, indicating that the system has higher exergy efficiency and is more environmentally friendly under strong solar radiation. Economic analysis indicates that the capital investment cost is 779.34 k$, and the revenue begins in the 9-th year.

Deterministic Optimization Approach for High-Performance Externally Fired Biomass-Fueled Micro-Gas Turbines

Abstract This work focuses on a dual-objective optimization of a 100 kWe externally fired micro-gas turbine utilizing the producer gas from a biomass gasifier. Although externally fired micro-gas turbines are convenient for resolving operability issues in biomass combined heat and power applications, these configurations are still lacking in efficiency compared to the commercial natural-gas fired microturbines. The main cause is the material temperature limitations in the recuperator and the current uneconomical use of high-temperature resistance materials. Toward the achievement of higher efficiency by keeping system economic viability, an optimization process is followed based on the Normal Constraint Method, which generates evenly distributed solutions of a Pareto front. The selected method can determine high-performance solutions, being unidentified by one-dimensional approaches, providing information about the distribution of critical cycle parameters, across the complete objective space by the evaluation of a relatively small set of Pareto points. These critical parameters are the pressure ratio, the recuperator temperature difference, and maximum temperature. The exergetic efficiency and the relative recuperator cost are the optimization objectives. The deterministic Nelder–Mead algorithm is used for the acquisition of Pareto solutions, along with a penalty-based method to perform the constrained optimization. The implemented optimization method can identify superior solutions compared to one-dimensional approaches, as the latter result in higher recuperator costs around 41–112% at the same exergetic efficiency, revealing that high-performance is not only restricted by the recuperator but also by the compressor operating range.