Numerical Study of a Small-Scale Micro Gas Turbine-ORC Power Plant Integrated With a Biomass Gasifier

2020 ◽  
Author(s):  
Fabrizio Reale ◽  
Raniero Sannino ◽  
Raffaela Calabria ◽  
Patrizio Massoli
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Combustion Stability ◽  
Small Scale ◽  
High Hydrogen ◽  
Micro Gas Turbine ◽  
Fuel Blends

Abstract The paper is focused on coupling a small-scale power plant, based on a micro gas turbine (mGT) and a bottoming Organic Rankine Cycle (ORC), with a biomass gasifier. The aim of this study is to define the optimal strategies to maximize the benefits related to distributed generation and to promote the organic solid waste gasification, in terms of energy efficiency and renewable sources exploitation. In particular, they were investigated the energetic performances of the system when the micro gas turbine was fed with several fuel blends, made by specific volume concentration of syngas and biogas. The low heating value of both considered fuels implies the necessity of operating the mGT in peculiar conditions as determined by the performance maps of compressor and turbine. Then, the thermodynamic analyses of the whole energy system have been carried out to evaluate the performance for each fuel. The high hydrogen content of syngas and the different thermodynamic properties of the studied fuel blends required a deeper investigation of the combustion process. In order to analyze the combustion stability and the fluid dynamic aspects, an accurate investigation of combustion chamber has been performed through a CFD solver. Finally, a comparison of the plant performances for each fuel blend have been reported, along with opportunities and critical aspects related to power plant integration.

Numerical Study of a Small-Scale Micro Gas Turbine-ORC Power Plant Integrated With a Biomass Gasifier

2021 ◽  
Author(s):  
Fabrizio Reale ◽  
Raniero Sannino ◽  
Raffaela Calabria ◽  
Patrizio Massoli
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Numerical Study ◽  
Small Scale ◽  
Micro Gas Turbine

scholarly journals Performance Analysis of Biomass Fuel Driven EFMGT Cycle

2019 ◽  
Vol 9 (2) ◽  
pp. 2421-2425
Keyword(s):  
Heat Exchanger ◽  
Power Plant ◽  
Gas Turbine ◽  
Electrical Power ◽  
Cost Effective ◽  
Biomass Fuel ◽  
Small Scale ◽  
Inlet Temperature ◽  
Micro Gas Turbine ◽  
Electrical Power Output

Biomass fuel as carbon neutral, abundant, domestic, cost effective is being reconsidered to fuel-up the power plant to produce electricity in clean way. But utilization of biomass fuel directly in existing conventional power plant causes problem in turbine such as erosion, hot corrosion, clogging and depositions [1]. As such combustion of biomass fuel outside the primary cycle eradicates potential hazards for turbine. In such a case indirectly fired micro gas turbine opens a door to biomass fuel as this technology is free from negative aspects of direct combustion as well as making micro gas turbine feasible to generate electricity in small scale at non-grid areas for individual consumer or group of consumers. In this research, the effect of different types of biomass fuel on operating parameters as well as on output electrical power of externally fired micro gas turbine (EFmGT)has been analyzed. The biomass fuels are categorized on the basis of air to fuel ratio (AFR) using stoichiometry combustion theory. It is found from results that parameters like air mass flow rate, compression ratio, heat exchanger effectiveness, turbine inlet temperature, combustion temperature, and temperature difference in heat exchanger affect the performance of EFmGT. Also types of biomass fuel have substantial impacts on these performance parameters as well as on electrical power output of EFmGT cycle.

Performance and Emission Assessment on a 3kW Micro Gas Turbine: Comparison of RANS and LES Predictions

2021 ◽  
Author(s):  
Alessio Pappa ◽  
Francesco F. Nicolosi ◽  
Antoine Verhaeghe ◽  
Laurent Bricteux ◽  
Massimiliano Renzi ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Industrial Applications ◽  
Combustion Stability ◽  
Navier Stokes ◽  
Small Scale ◽  
Significant Discrepancy ◽  
Performance And Emission ◽  
Micro Gas Turbine ◽  
Inlet Conditions ◽  
The Impact

Abstract Computational fluid dynamics represent a powerful tool to assess the performance of a combustor and identify possible issues/instabilities, helping thus e.g. to investigate the impact of advanced cycle modifications on the combustion in mGTs. The steady Reynolds-averaged Navier-Stokes (RANS) approach is still mostly used in this framework. With growing computational power, Large Eddy Simulation (LES) has gained more interest. LES provides higher details concerning flow structures and can better predict possible instabilities, specifically needed for advanced cycle modelling. On the other hand, LES remain rather challenging for real industrial applications. This work aims at providing an answer whether the advantages of LES justify the much higher computational costs. The objective of the present study is thus to assess the combustion performance and emissions of a typical small-scale 3.2 kWe micro gas turbine (mGT), using steady RANS and LES for various fuels. In this framework, a comparison of RANS and LES approaches (two levels of fidelity) is performed on a typical industrial case, to point out the strengths and weakness of each method with regard to industrial and research needs. The results show that both RANS (at a reduced cost) and LES can accurately predict the time-averaged trends of the main performance parameters, like temperature levels and emissions, also using various non-conventional inlet conditions. For the accurate prediction of the instabilities, the LES approach stands out as this approach takes into account the time-variation of the different quantities. Finally, a significant discrepancy has been observed between the CO levels provided by RANS and LES approaches where LES is overestimating the level of CO in the exhaust gases. Whereas it is difficult for LES to compete with convincing results provided by RANS, especially in the prediction of global emissions at reduced simulation cost, the LES strengths come out especially in flame and combustion stability analysis.

Numerical Investigation of Perfectly Premixed Combustion and the Effect of NOx Emission for Syngas in a Gas Turbine Combustor

2015 ◽  
Author(s):  
Sarzina Hossain ◽  
Mohammad A. Hossain
Keyword(s):  
Gas Turbine ◽  
Numerical Study ◽  
Control Volume ◽  
Combustion Process ◽  
Transport Processes ◽  
Combined Cycle ◽  
Premixed Combustion ◽  
Nox Emission ◽  
High Hydrogen ◽  
Dissipation Model

Integrated Gasification Combined Cycle (IGCC) is a gasification process that is used to produce syngas from variety of fossil fuels, including coal, biomass, organic waste, and refinery residual. It contains variable composition of CO and H2. Because of its wide fuel flexibility, the syngas is considered as most effective fuel particularly for power generation purposes. These types of high hydrogen content fuel faces a great difficulty to lower the NOx emission due to its high flame speed, low ignition energy can cause flashback. This paper is focused on the syngas combustion along with the NOx emissions for different equivalence ratios for a multi-tube injector inside a gas turbine combustion chamber. This paper describes the numerical study of the emissions of nitrogen oxides (NOx) for perfectly premixed combustion using CFD combustion modeling. In this study CO+H2 is mixed with air in lean equivalence ratio. The CFD Eddy Dissipation model is used to study the perfectly premixed combustion. Commercial software ANSYS Fluent has been used for CFD analysis. The Eddy Dissipation model is best for turbulent flows when the chemical reaction rate is fast relative to the transport processes in the flow. There is no kinetic control of the reaction process. The Eddy Dissipation model is sufficient enough for the combustion process if air and fuel is available in a control volume.

scholarly journals Combustion of Fuel Surrogates: An Application to Gas Turbine Engines

2021 ◽  
Author(s):  
Mansour Al Qubeissi ◽  
Nawar Al-Esawi ◽  
Hakan Serhad Soyhan
Keyword(s):  
Gas Turbine ◽  
Combustion Process ◽  
Chemical Mechanism ◽  
Cfd Modelling ◽  
Ansys Fluent ◽  
Turbine Engine ◽  
Fuel Blends ◽  
Combustion Simulation ◽  
Fuel Surrogate ◽  
Fuel Surrogates

The previously developed models for fuel droplet heating and evaporation processes, mainly the Discrete Multi Component Model (DMCM), and Multi-Dimensional Quasi-Discrete Model (MDQDM) are investigated for the aerodynamic combustion simulation. The models have been recently improved, and generalised for a broad range of bio-fossil fuel blends so that the application areas are broadened with increased accuracy. The main distinctive features of these models are that they consider the impacts of species thermal conductivities and diffusivities within the droplets to account for the temperature gradient, transient diffusion of species and recirculation. A formulation of fuel surrogates is made, using the recently introduced model, referred to as ‘’Complex Fuel Surrogate Model (CFSM)’’ and analysing their heating, evaporation, and combustion characteristics. The CFSM is aimed to reduce the full composition of fuel to a much smaller number of components based on their mass fractions, and to formulate fuel surrogates. Such approach has provided a proof of concept with the implementation of the developed model into a commercial CFD code ANSYS-Fluent. A case study is made for the CFD modelling of gas-turbine engine using kerosene fuel surrogate. The surrogate is proposed using the CFSM. The model is implemented into ANSYS-Fluent via a user-defined function to provide the first full simulation of the combustion process. Detailed chemical mechanism is also implemented into ANSYS Chemkin for the combustion study.

Model Simulation and Design Optimization of a Can Combustor with Methane/Syngas Fuels for a Micro Gas Turbine

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Chi-Rong Liu ◽  
Ming-Tsung Sun ◽  
Hsin-Yi Shih
Keyword(s):  
Gas Turbine ◽  
Turbulent Flows ◽  
Film Cooling ◽  
Fuel Injection ◽  
Model Simulation ◽  
Combustion Process ◽  
Three Dimensional ◽  
Future Application ◽  
Detailed Chemical Kinetics ◽  
Micro Gas Turbine

Abstract The design and model simulation of a can combustor has been made for future syngas combustion application in a micro gas turbine. An improved design of the combustor is studied in this work, where a new fuel injection strategy and film cooling are employed. The simulation of the combustor is conducted by a computational model, which consists of three-dimensional, compressible k-ε model for turbulent flows and PPDF (Presumed Probability Density Function) model for combustion process invoking a laminar flamelet assumption generated by detailed chemical kinetics from GRI 3.0. Thermal and prompt NOx mechanisms are adopted to predict the NO formation. The modeling results indicated that the high temperature flames are stabilized in the center of the primary zone by radially injecting the fuel inward. The exit temperatures of the modified can combustor drop and exhibit a more uniform distribution by coupling film cooling, resulting in a low pattern factor. The combustion characteristics were then investigated and the optimization procedures of the fuel compositions and fuel flow rates were developed for future application of methane/syngas fuels in the micro gas turbine.

Experimental and numerical study of flame structure and emissions in a micro gas turbine combustor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vedant Dwivedi ◽  
Srikanth Hari ◽  
S. M. Kumaran ◽  
B. V. S. S. S. Prasad ◽  
Vasudevan Raghavan
Keyword(s):  
Gas Turbine ◽  
Rural Areas ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
Numerical Study ◽  
Operating Conditions ◽  
Emission Characteristics ◽  
Nitric Oxides ◽  
Gas Turbine Combustor ◽  
Micro Gas Turbine

Abstract Experimental and numerical study of flame and emission characteristics in a tubular micro gas turbine combustor is reported. Micro gas turbines are used for distributed power (DP) generation using alternative fuels in rural areas. The combustion and emission characteristics from the combustor have to be studied for proper design using different fuel types. In this study methane, representing fossil natural gas, and biogas, a renewable fuel that is a mixture of methane and carbon-dioxide, are used. Primary air flow (with swirl component) and secondary aeration have been varied. Experiments have been conducted to measure the exit temperatures. Turbulent reactive flow model is used to simulate the methane and biogas flames. Numerical results are validated against the experimental data. Parametric studies to reveal the effects of primary flow, secondary flow and swirl have been conducted and results are systematically presented. An analysis of nitric-oxides emission for different fuels and operating conditions has been presented subsequently.

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