Performance Of Micro Gas Turbine Research Articles

Numerical Modelling and Design Experiment of a Model Gas Turbine Petro with Combination of Natural Gas, Hydrogen

Abstract: In this study, we are constructing an analytical model to evaluate the energy performance of a Micro Gas Turbine (MGT) utilizing H2 NG mixes as fuel. During the experimental campaign, the model findings were verified in the real working conditions of the Micro Gas Turbine. It was during the spring and summer of this year that a model validation experiment was carried out. Fueled by H2 NG, MGT performance has been shown to increase from zero to 10 percent hydrogen content, with a 2 percent volume step. Fuel usage has been considerably decreased, according to the data. Heat recovery and electrical reliability increase marginally even if environmental conditions have an influence on the system. A MATLAB-Simulink numerical model was built to depict the MGT's operation. As a consequence, the relative standard errors of the major output parameters have been determined.

The Heat-Storing Micro Gas Turbine—Process Analysis and Experimental Investigation of Effects on Combustion

Renewable energy sources such as wind turbines and photovoltaics are the key to an environmentally friendly energy supply. However, their volatile power output is challenging in regard to supply security. Therefore, flexible energy systems with storage capabilities are crucial for the expansion of renewable energy sources since they allow storing off-demand produced power and reconverting and supplying it on-demand. For this purpose, a novel power plant concept is presented where high-temperature energy storage (HTES) is integrated between the recuperator and the combustor of a conventional micro gas turbine (MGT). It is used to store renewable energy in times of oversupply, which is later used to reduce fuel demand during MGT operation. Hereby, pollutant emissions are reduced significantly, while the power grid is stabilized. This paper presents a numerical process simulation study, aiming to examine the influence of different storage temperatures and load profiles of HTES on the MGT performance (e.g., fuel consumption, efficiency). Furthermore, relevant operating points and their process parameters such as pressures, temperatures, and mass-flow rates are derived. As operation conditions for the combustor are strongly influenced by the HTES, the paper contains a detailed theoretical analysis of the impact on combustor operability and includes an experimental investigation of the first combustor design adapted for the compound and tested under higher inlet temperatures conditions.

Predicting the performance of a micro gas turbine under solar-hybrid operation

There are currently no commercial solar-hybrid gas turbine systems readily available off-the-shelf. Several operation and control challenges still exist, and significant development effort is still required to provide technically proven units. To address this gap, this study modeled the performance of a solar-hybrid micro gas turbine (MGT) system, considering both steady-state and transient operation. Based on the component matching, the equilibrium running point shifted on the compressor characteristic, to counter the additional system pressure losses, and ensure a useful work output, albeit with a reduced surge margin. Solar-hybrid operation was only possible for solar share of at least 20%, while the work output and cycle thermal efficiency drop below standard operation levels beyond certain solar share. In contrast to standard operation, a higher nominal work output of 20 kW, at a lower SFC of 0.0004 kg/kWh and a higher cycle thermal efficiency of 8% was predicted, the latter potentially increasing to 20% with recuperation. Solar-hybrid equilibrium running could eliminate the risk of running into compressor surge. The findings from this study should guide operation and control strategies for the proposed, and future solar-hybrid MGT systems, which should in turn contribute to their development and commercialization.

Performance and emissions of liquefied wood as fuel for a small scale gas turbine

This study investigates for the first time the combustion in a micro gas turbine (MGT) of a new bioliquid, a viscous biocrude, which is a liquefied wood (LW) produced via solvolysis of lignocellulosic biomass in acidified glycols. The test rig includes a modified fuel injection line, a re-designed combustion chamber and revised fuel injection positions. The main novelties of this work are: (1) producing of liquefied wood with pure ethylene glycol as a solvent, and methanesulfonic acid as a catalyst, to obtain a bio-crude with lower viscosity and higher lignocellulosics content than previous tested formulations; (2) upgrading raw liquefied wood by blending it with ethanol to further reduce the viscosity of the mixture; (3) utilizing a commercially available MGT Auxiliary Power Unit (APU) of 25 kW electrical power output, with notably reduced extent of adaptations to use the newly obtained fuel mixture. Fuel properties, and their impact on combustion performance using liquefied wood, are investigated by analyzing MGT performance and emissions response at different load and blend ratios. Emissions revealed that the presence of LW in the blends significantly affects CO and NOX concentrations compared to conventional fuels. CO roughly increased from 600 ppm (pure ethanol as fuel) to 1500 ppm (at 20 kW electrical power). The experimental study reveals that it is possible to achieve efficient MGT operation while utilizing high biocrude to ethanol ratios, but a number of adaptations are necessary. The achieved maximum share of liquefied wood in the fuel blend is 47.2% at 25 kW power output. Main barriers to the use of higher share of liquefied wood in these type of systems are also summarized.

Application of Micro Gas Turbine in Range-Extended Electric Vehicles

The increasing number of passenger cars worldwide and the consequent increasing rate of global oil consumption have raised the attention on fuel prices and have caused serious problems to the environment. Nowadays, the demand for reducing fuel consumption and pollutant emissions has paved the way to the development of more efficient power generation systems for the transportation sector. The lower fuel burning and pollutant emissions of hybrid electric vehicles give a strong motivation and encourage further investigations in this field. This research aims to investigate novel configurations, which could achieve further performance benefits for vehicle powertrain. Automakers claim that the employment of a gas turbine operating as range extender in a series hybrid configuration is the most efficiency solution in the coming years. In particular, a Micro Gas Turbine (MGT) can be considered as an alternative to the internal combustion engine (ICE) as a range extender for electric vehicles. The MGT produces less raw exhaust gaseous emissions such as HC and CO and static applications compared to the ICE. In addition, the MGT weight is lower than an equivalent ICE and potentially can reduce the level of CO2 especially in a vehicle application. This study presents a parametric study of MGT applications for Range-Extended Electric Vehicle (REEV). The main objective is to examine the MGT performance to meet the requirements for a REEV that could become competitive, in terms of fuel consumption and pollutant emissions, to equivalent diesel or gasoline hybrid propulsion units or to conventional diesel vehicle.

Syngas feed of micro gas turbines with steam injection: Effects on performance, combustion and pollutants formation

In this work, the performance of a 100kW Micro Gas Turbine (MGT) fed by biomass-derived Synthesis gas (S) have been assessed using a simulation algorithm, consisting of a set of equations describing the behavior of the turbomachines, the pressure losses in each component, as well as the consumption of the other auxiliary devices. An additional algorithm using Cantera’s library has been developed in order to study the combustion kinetics and to assess the MGT emissions with S and with natural gas (NG) feed.The electric power output, achieved using S with a Lower Heating Value (LHV) of about 9MJ/kg, turns out to be similar to that achieved with NG, if a proper fuel injection strategy is adopted; efficiency is slightly lower, mainly because of the variation of the working fluid composition which involves an increase of the heat required to run the machine. In this work, the effect of the steam injection on the MGT performance characteristics has been also investigated with both NG and S. Steam injection allows to obtain higher power and efficiencies at the rated rotational speed. Attention must be paid to the risk of the compressor stall, especially when using S, as the mass flow rate processed by the compressor decreases significantly. As regards the pollutants’ emission, S combustion involves a reduction of NOX emissions of about 75%, while CO emissions slightly increase with respect to natural gas combustion. However, it was found that, with a proper fuel and steam injection strategy, the concentration of the polluting compounds can be further reduced.Moreover, another advantage of adopting the steam injection technique lies in the increased flexibility of the system: according to the users’ needs, the discharged heat can be exploited to generate steam, thus to enhance the electric performance, or to supply thermal power.

Nonlinear modeling of regenerative cycle micro gas turbine

In this paper, a nonlinear mathematical model of modern regenerative MGT (micro gas turbine) with superior accuracy is developed. The regenerator can improve efficiency and slow dynamic response of MGT. In view of its significant influence on MGT performance, the average static and dynamic model of the regenerator is included. In order to get more accurate mathematical description for off-design condition performance characteristic of compressor and turbine, nonlinear analytical expressions of compressor and turbine are employed instead of polynomial approximate expressions. The specific expressions of nonlinear state space equations are deduced in this paper. Static simulation results prove the correctness and validity of the model. In this paper, the new model is adopted to analyze dynamic characteristic of MGT having regenerator. The new nonlinear model can be used to thoroughly study performance characteristic of MGT and design superior nonlinear controller.

B125 超小型遠心コンプレッサの性能向上に向けた数値解析(OS-8:マイクロ・ナノ熱工学(2))

This study focuses on an analysis of the compressor performance of a micro gas turbine to realize an improved micro gas turbine design. For this purpose, the performance of the compressor is determined, and the results are feedback for an experiment. Heat transfer impacts greatly the performance of whole micro gas turbine than other gas turbine because the distance between the compressor and the turbine or combustor is small in micro gas turbines. The obtained values when heat transfer is not considered did not satisfy the design requirements. Therefore, the compressor model could not perform sufficiently well. Furthermore, when heat transfer is considered in the model, a decrease of approximately 32% is observed in the compressor performance in comparison to models in which heat transfer is not considered.

Theoretical analysis of performance of a micro gas turbine co/trigeneration system for residential buildings in a tropical region

This study shows performance of micro gas turbine (MGT) based cogeneration system (CGS) and trigeneration system (TGS) in residential buildings located in the area with a tropical climate. Energy, economic and environmental performance of MGT-CGS and MGT-TGS were studied. MGT-CGS consists of an MGT and an exhaust heat exchanger (EHE), whereas MGT-TGS consists of an MGT, an EHE, an absorption heat pump and a heat storage. Heat storage was essential for storing heat generated during daytime to be utilized during night-time in which heat demand was higher. MGT-TGS was a better configuration compared to MGT-CGS because it can utilize more exhaust heat and had Energy Recovery Utilized Efficiency (ηER,utilized) of 0.37 and 0.80 during daytime and night-time, respectively. Furthermore, the payback period for the MGT-TGS was also shorter than MGT-CGS, 13.8 years under highly subsidized electricity tariff. The MGT-TGS also had a higher Fuel Energy Saving Index FESI when compared to a gas turbine, but had a lower FESI when compared to a combined cycle gas turbine. MGT-CGS and MGT-TGS can also reduce pollutants especially NOx emissions compared to conventional systems.

Effect of ambient temperature on the performance of micro gas turbine with cogeneration system in cold region

Abstract A small-scale prime mover especially micro gas turbine is a key factor in order to widespread the utilization of biogas. It is well known that a performance of large-scale gas turbine is greatly affected by its inlet air temperature. However, the effect of the inlet air temperature on the performance of small-scale gas turbine (micro gas turbine) is not widely reported. The purpose of the present study is to investigate the effect of the inlet air temperature on the performance of a micro gas turbine (MGT) with cogeneration system (CGS) arrangement. An analysis model of the MGT–CGS was set up on the basis of experimental results obtained in a previous study and a manufacturer standard data, and it was analysed under a various ambient temperature condition in a cold region. The results show that when ambient temperature increased, electrical efficiency ηele of the MGT decreased but exhaust heat recovery ηehr increased. It was also found that when ambient temperature increased, exhaust heat to mass flow rate Qexe/me and exhaust heat recovery to mass flow rate Qehr/me increased, with maximum ratios of 259 kJ/kg and 200 kJ/kg, respectively were found in summer peak. Furthermore, it was also found that the exhaust heat to power ratio Qexe/Pe had a similar characteristic with exhaust heat recovery to power ratio Qehr/Pe. Qexe/Pe and Qehr/Pe increased with the increase of ambient temperature. Moreover, although different values of total energy efficiency, fuel energy saving and CO2 reduction for every temperature condition were found comparing with a two conventional system that were considered, the MGT–CGS could annually reduce 30,000–80,000 m3/y of fuel consumption and 35–94 t-CO2/y of CO2 emissions.

Application of artificial neural networks to micro gas turbines

In this work, artificial neural networks (ANNs) were applied to describe the performance of a micro gas turbine (MGT). In particular, they were used (i) to complete performance diagrams for unavailable experimental data; (ii) to assess the influence of ambient parameters on performance; and (iii) to analyze and predict emissions of pollutants in the exhausts. The experimental data used to feed the ANNs were acquired from a manufacturer’s test bed. Though large, the data set did not cover the whole working range of the turbine; ANNs and an artificial neural fuzzy interference system (ANFIS) were therefore applied to fill information gaps. The results of this investigation were also used for sensitivity analysis of the machine’s behavior in different ambient conditions. ANNs can effectively evaluate both MGT performance and emissions in real installations in any climate, the worst R 2 in the validation set being 0.9962.

A micro gas turbine for UK domestic combined heat and power

Various micro-radial compressor configurations were investigated using one-dimensional meanline and computational fluid dynamics (CFD) techniques for use in a micro gas turbine (MGT) domestic combined heat and power (DCHP) application. Blade backsweep, shaft speed, and blade height were varied at a constant pressure ratio. Shaft speeds were limited to 220 000 r/min, to enable the use of a turbocharger bearing platform. Off-design compressor performance was established and used to determine the MGT performance envelope; this in turn was used to assess potential cost and environmental savings in a heat-led DCHP operating scenario within the target market of a detached family home. A low target-stage pressure ratio provided an opportunity to reduce diffusion within the impeller. Critically for DCHP, this produced very regular flow, which improved impeller performance for a wider operating envelope. The best performing impeller was a low-speed, 170 000 r/min, low-backsweep, 15° configuration producing 71.76 per cent stage efficiency at a pressure ratio of 2.20. This produced an MGT design point system efficiency of 14.85 per cent at 993 W, matching prime movers in the latest commercial DCHP units. Cost and CO2 savings were 10.7 per cent and 6.3 per cent, respectively, for annual power demands of 17.4 MWht and 6.1 MWhe compared to a standard condensing boiler (with grid) installation. The maximum cost saving (on design point) was 14.2 per cent for annual power demands of 22.62 MWht and 6.1 MWhe corresponding to an 8.1 per cent CO2 saving. When sizing, maximum savings were found with larger heat demands. When sized, maximum savings could be made by encouraging more electricity export either by reducing household electricity consumption or by increasing machine efficiency.

Numerical analyses and experiment investigations of an annular micro gas turbine power system using fuels with low heating values

This study investigates the effects of using fuels with low heating values on the performance of an annular micro gas turbine (MGT) experimentally and numerically. The MGT used in this study is MW-54, whose original fuel is liquid (Jet A1). Its fuel supply system is re-designed to use biogas fuel with low heating value (LHV). The purpose is to reduce the size of a biogas distributed power supply system and to enhance its popularization. This study assesses the practicability of using fuels with LHVs by using various mixing ratios of methane (CH4) and carbon dioxide (CO2). Prior to experiments, the corresponding simulations, aided by the commercial code CFD-ACE+, were carried out to investigate the cooling effect in a perforated combustion chamber and combustion behavior in an annular MGT when LHV gas was used. The main purposes are to confirm that there are no hot spots occurring in the liners and the exhaust temperatures of combustor are lower than 700°C when MGT is operated under different conditions. In experiments, fuel pressure and mass flow rate, turbine rotational speed, generator power output, and temperature distribution were measured to analyze MGT performance. Experimental results indicate that the presented MGT system operates successfully under each tested condition when the minimum heating value of the simulated fuel is approximately 50% of pure methane. The power output is around 170 W at 85000 r/min as 90% CH4 with 10% CO2 is used and 70 W at 60000 r/min as 70% CH4 with 30% CO2 is used. When a critical limit of 60% CH4 is used, the power output is extremely low. Furthermore, the best theoretical Brayton cycle efficiency for such MGT is calculated as 23% according to the experimental data while LHV fuel is used. Finally, the numerical results and experiment results reveal that MGT performance can be improved further and the possible solutions for performance improvement are suggested for the future studies.

System Development of Micro Gas Turbine Co-Generation

The new market penetration using the distributed generation technology is linked to a large number of factors like economics and performance, safety and reliability, market regulations, environmental issues, or grid connection standards. KEPCO, a government company in Korea, has performed the project to identify and evaluate the performance of Micro Gas Turbine (MGT) technologies focused on 30, 60kW-class grid-connected optimization and combined Heat & Power performance. This paper describes the results for the mechanical, electrical, and environmental tests of MGT on actual grid-connection under Korean regulations. As one of the achievements, the simulation model of Exhaust-gas Absorption Chiller was developed, so that it will be able to analyze or propose new distributed generation system using MGT.

Integrated CHP with autothermal biomass gasification and SOFC–MGT

Autothermal biomass gasification produces a gaseous fuel that, after gas cleaning and conditioning, can be used in solid oxide fuel cells (SOFC). Conceptually, the integrated system can be near atmospheric or at elevated pressures, allowing combination with a micro gas turbine (MGT) expander. This work comparatively investigates three small scale combined heat and power (CHP) configurations that integrate these technologies: (a) gasification at 4 bar and MGT, (b) gasification at 1.4 bar and SOFC and (c) gasification at 4 bar and SOFC–MGT. Aspenplus™ process simulation software was used for modelling each major and peripheral component of the CHP. Interestingly, the MGT system proved more efficient than the atmospheric SOFC, both of which were surpassed by SOFC–MGT performance that reached an exergetic electrical efficiency of 35.6% using an SOFC of 100 m 2 active surface area and nominal biomass throughput of 200 kg/h. An exergy analysis allowed optimisation of the SOFC fuel utilisation factor ( U f) and efficiency impact of system capacity and level of product gas moistening prior to the cell.