Experimental Investigation of the Impact of Biogas on a 3 kW Micro Gas Turbine FLOX\xae -Based Combustor

Abstract The use of biogas has currently two disadvantages. Firstly, processing biogas to natural gas quality for feeding into the natural gas grid is a rather energy consuming process. Secondly, the conversion into electricity directly in biogas plants produces waste heat, which largely cannot be used. Therefore, a feed-in of the desulfurized and dry biogas to local biogas grids would be preferable. Thus, the biogas could be used directly at the end consumer for heat and power production. As biogas varies in its methane (CH4) and carbon dioxide (CO2) content, respectively, this paper studies the influence of different biogas mixtures compared to natural gas on the combustion in a FLOX®-based six nozzle combustor. The single staged combustor is suitable for the use in a micro gas turbine (MGT) based combined heat and power (CHP) system with an electrical power output of 3 kW. The combustor is studied in an optically accessible atmospheric test rig, as well as integrated into the MGT system. This paper focuses on the influence of the admixture of CO2 to natural gas on the NOX and CO emissions. Furthermore, at atmospheric conditions the shape and location of the heat release zone is investigated using OH* chemiluminescence (OH* CL). The combustor could be stably operated in the MGT within the complete stationary operating range with all fuel mixtures.

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Experimental Investigation of A Twin Shaft Micro Gas-Turbine System

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/16/1/012011 ◽

2013 ◽

Vol 16 ◽

pp. 012011

Author(s):

Hussain Sadig ◽

Shaharin Anwar Sulaiman ◽

Idris Ibrahim

Keyword(s):

Experimental Investigation ◽

Gas Turbine ◽

Micro Gas Turbine

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Experimental investigation of a novel micro gas turbine with flexible switching function for distributed power system

Frontiers in Energy ◽

10.1007/s11708-020-0691-2 ◽

2020 ◽

Vol 14 (4) ◽

pp. 790-800

Author(s):

Xiaojing Lv ◽

Weilun Zeng ◽

Xiaoyi Ding ◽

Yiwu Weng ◽

Shilie Weng

Keyword(s):

Experimental Investigation ◽

Power System ◽

Gas Turbine ◽

Switching Function ◽

Distributed Power ◽

Micro Gas Turbine ◽

Distributed Power System

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Experimental Investigation of the Performance of a Micro Gas Turbine Fueled With Mixtures of Natural Gas and Biogas

Volume 6A: Energy ◽

10.1115/imece2013-64299 ◽

2013 ◽

Cited By ~ 4

Author(s):

Homam Nikpey ◽

Mohsen Assadi ◽

Peter Breuhaus

Keyword(s):

Natural Gas ◽

Gas Turbine ◽

Co2 Emissions ◽

Fuel Mixture ◽

Combined Heat And Power ◽

Test Rig ◽

Heating Value ◽

Micro Gas Turbine ◽

Fuel Mixtures ◽

The Impact

Previously published studies have addressed modifications to the engines when operating with biogas, i.e. a low heating value (LHV) fuel. This study focuses on mapping out the possible biogas share in a fuel mixture of biogas and natural gas in micro combined heat and power (CHP) installations without any engine modifications. This contributes to a reduction in CO2 emissions from existing CHP installations and makes it possible to avoid a costly upgrade of biogas to the natural gas quality as well as engine modifications. Moreover, this approach allows the use of natural gas as a “fallback” solution in the case of eventual variations of the biogas composition and or shortage of biogas, providing improved availability. In this study, the performance of a commercial 100kW micro gas turbine (MGT) is experimentally evaluated when fed by varying mixtures of natural gas and biogas. The MGT is equipped with additional instrumentation, and a gas mixing station is used to supply the demanded fuel mixtures from zero biogas to maximum possible level by diluting natural gas with CO2. A typical biogas composition with 0.6 CH4 and 0.4 CO2 (in mole fraction) was used as reference, and corresponding biogas content in the supplied mixtures was computed. The performance changes due to increased biogas share were studied and compared with the purely natural gas fired engine. This paper presents the test rig setup used for the experimental activities and reports results, demonstrating the impact of burning a mixture of biogas and natural gas on the performance of the MGT. Comparing with when only natural gas was fired in the engine, the electrical efficiency was almost unchanged and no significant changes in operating parameters were observed. It was also shown that burning a mixture of natural gas and biogas contributes to a significant reduction in CO2 emissions from the plant.

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Experimental Investigation of the Effect of Steam Dilution on the Combustion of Methane for Humidified Micro Gas Turbine Applications

Combustion Science and Technology ◽

10.1080/00102202.2016.1174116 ◽

2016 ◽

Vol 188 (8) ◽

pp. 1199-1219 ◽

Cited By ~ 8

Author(s):

Ward De Paepe ◽

Parisa Sayad ◽

Svend Bram ◽

Jens Klingmann ◽

Francesco Contino

Keyword(s):

Experimental Investigation ◽

Gas Turbine ◽

Micro Gas Turbine

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Design, Numerical Simulation and Experimental Investigation of Radial Inflow Micro Gas Turbine

Journal of Applied Fluid Mechanics ◽

10.29252/jafm.12.06.29782 ◽

2019 ◽

Vol 12 (6) ◽

pp. 1905-1917

Author(s):

S. P. Shah ◽

S. A. Channiwala ◽

D. B. Kulshreshtha ◽

G. C. Chaudhari ◽

◽

...

Keyword(s):

Numerical Simulation ◽

Experimental Investigation ◽

Gas Turbine ◽

Micro Gas Turbine

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

10.1115/gt2021-59618 ◽

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.

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Prediction and Mitigation Strategies for Compressor Instabilities due to Large Pressurized Volumes in Micro Gas Turbine Systems

10.1115/gt2021-59106 ◽

2021 ◽

Author(s):

Thomas Krummrein ◽

Martin Henke ◽

Timo Lingstädt ◽

Martina Hohloch ◽

Peter Kutne

Keyword(s):

Gas Turbine ◽

Gas Turbines ◽

Power Plants ◽

Flow Instability ◽

Measurement Data ◽

Mitigation Strategies ◽

Mathematical Explanation ◽

Shaft Speed ◽

Micro Gas Turbine ◽

The Impact

Abstract Micro gas turbines are a versatile platform for advanced cycle concepts. In these novel cycles, basic micro gas turbine components — compressor, turbine, combustor and recuperator — are coupled with various other technologies to achieve higher efficiency and flexibility. Examples are hybrid power plants integrating pressurized fuel cells, solar receivers or thermal storages. Characteristically, such complex cycles contain vast pressurized gas volumes between compressor and turbine, many times larger than those contained in conventional micro gas turbines. In fast deceleration maneuvers the rotational speed of the compressor drops rapidly. However, the pressure decrease is delayed due to the large amount of gas contained in the volumes. Ultimately, this can lead to compressor flow instability or surge. To predict and mitigate such instabilities, not only the compressor surge limit must be known, but also the dynamic dependencies between shaft speed deceleration, pressure and flow changes within the system. Since appropriate experiments may damage the system, investigations with numerical simulations are crucial. The investigation begins with a mathematical explanation of the relevant mechanisms, based on a simplified analytical model. Subsequently, the DLR in-house simulation program TMTSyS (Transient Modular Turbo-System Simulator) is used to investigate the impact of transient maneuvers on a micro gas turbine test rig containing a large pressurized gas volume in detail. After the relevant aspects of the simulation model are validated against measurement data, it is shown that the occurrence of compressor instabilities induced by fast deceleration can be predicted with the simulator. It is also shown that the simulation tool enables these predictions using only measurement data of non-critical maneuvers. Hence, mitigation strategies are derived that allow to estimate save shaft speed deceleration rate limits based on non-critical performance measurements.

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