Small scale gas turbine combustor sizing

Michal Czarnecki

doi:10.24136/atest.2019.032

Small scale gas turbine combustor sizing

AUTOBUSY – Technika Eksploatacja Systemy Transportowe ◽

10.24136/atest.2019.032 ◽

2019 ◽

Vol 20 (1-2) ◽

pp. 180-184

Author(s):

Michal Czarnecki

Keyword(s):

Boundary Conditions ◽

Gas Turbine ◽

Small Scale ◽

Gas Turbine Combustor ◽

Full Size ◽

Micro Scale ◽

Initial Design ◽

Numeric Model ◽

Complex Process ◽

Prototype Design

Presented article is focused on initial design of small scale combustors for micro scale jest engines. In comparison to the full size equivalent, small combustor are design and manufactured in experimental way. To try building universal numeric model for micro size design is important to acquire as many data as possible to identify boundary conditions for a model. Major advantage of analyzing different design is possibility to quick building prototype design without investigating complex process of combustion.

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Grasp of the influence of temperature distribution in the tube simulating a gas turbine combustor on acoustic boundary conditions

The Proceedings of Mechanical Engineering Congress Japan ◽

10.1299/jsmemecj.2019.j09104p ◽

2019 ◽

Vol 2019 (0) ◽

pp. J09104P

Author(s):

Kosuke AKINO ◽

Akane UEMICHI ◽

Yudai YAMASAKI ◽

Shigehiko KANEKO

Keyword(s):

Temperature Distribution ◽

Boundary Conditions ◽

Gas Turbine ◽

Gas Turbine Combustor ◽

Acoustic Boundary Conditions ◽

Influence Of Temperature

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Development of a Small-Scale Catalytic Gas Turbine Combustor

Journal of Engineering for Power ◽

10.1115/1.3227265 ◽

1982 ◽

Vol 104 (1) ◽

pp. 52-57 ◽

Cited By ~ 2

Author(s):

S. J. Anderson ◽

M. A. Friedman ◽

W. V. Krill ◽

J. P. Kesselring

Keyword(s):

Steady State ◽

Gas Turbine ◽

Gas Turbines ◽

Combustion Efficiency ◽

Small Scale ◽

Time Interval ◽

Nox Emissions ◽

Fuel Injector ◽

Gas Turbine Combustor ◽

Opposed Jet

Catalytically supported thermal combustion can provide low NOx emissions with gaseous and distillate fuels while maintaining high combustion efficiency. For stationary gas turbines, catalytic combustion may be the only emerging technology that can cost effectively meet recent federal regulations for NOx emissions. Under EPA sponsorship, a small-scale, catalytic gas turbine combustor was developed to evaluate transient and steady state combustor performance. The combustor consisted of a multiple air-atomizing fuel injector, an opposed jet igniter, and a graded-cell monolithic reactor. System startup, including opposed jet ignition and catalyst stabilization, was achieved in 250 seconds. This time interval is comparable to conventional gas turbines. Steady state operation was performed at 0.505 MPa (5 atmospheres) pressure and 15.3 m/s (50 ft/s) reference velocities. Thermal NOx emissions were measured below 10 ppmv, while fuel NOx conversion ranged from 75 to 95 percent. At catalyst bed temperatures greater than 1422K (2100°F), total CO and UHC emissions were less than 50 ppmv indicating combustion efficiency greater than 99.9 percent. Compared with conventional gas turbine combustors, the catalytic reactor operates only within a relatively narrow range of fuel/air ratios. As a result, modified combustor air distribution or fuel staging will be required to achieve the wide turndown required in large stationary systems.

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Resolving Large- and Small-Scale Structures in the Swirl Flow of a Typical Land-Based Gas Turbine Combustor Single Nozzle Rig

Volume 4B: Combustion, Fuels and Emissions ◽

10.1115/gt2014-26615 ◽

2014 ◽

Author(s):

R. K. R. Katreddy ◽

S. R. Chakravarthy

Keyword(s):

Velocity Field ◽

Gas Turbine ◽

Large Scale ◽

Recirculation Zone ◽

Laser Diagnostics ◽

Swirl Flow ◽

Sudden Expansion ◽

Small Scale ◽

Gas Turbine Combustor ◽

Scale Structures

The present study focuses on identifying and resolving large-scale energy containing structures and turbulent eddies in a typical gas turbine combustor single nozzle rig, using particle image velocimetry in cold flow. A generic fuel-air nozzle through a swirler is integrated with a sudden expansion square duct with optical access to perform laser diagnostics. Experiments are conducted to analyze the swirl flow field under starting and operating flow conditions. Three-component velocities are obtained in cross-sectional planes of Z/D = 0, 1.25, and 2.5 (normalized by the nozzle diameter), and two-component velocities are obtained in the mid-plane along the longitudinal (Z-) axis from Z/D = 0 to 2.5D. Velocity splitting is performed using spatial Gaussian smoothing with a kernel with filter width equal to integral scale is performed over the velocity fields to resolve the field of large-scale energy containing eddies. Proper orthogonal decomposition is performed over the large-scale velocity field, and the modes obtained indicate the existence of the precessing vortex core (PVC), formation of small scales Kelvin-Helmholtz (K-H) vortices for Z/D < 1.25D, and large-scale growing K-H structures in 1.25D < Z/D < 2.5D. Turbulent kinetic energy (TKE) is obtained from the turbulent velocity fluctuations below the integral length scale and is observed to be higher at the interface of the corner recirculation zone (CRZ) and central toroidal recirculation zone (CTRZ). Resolving the swirl velocity field obtained in the above manner into large-scale structures formed by the PVC, CTRZ, K-H vortices, CRZ, and small-scale turbulence field, indicates the clear distinction in rapid mixing zones and unsteady convective zones. The length-scales and zones of these structures within the swirl combustor are identified.

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Design and Testing of a Micromix Combustor With Recuperative Wall Cooling for a Hydrogen Fuelled μ-Scale Gas Turbine

Volume 5: Industrial and Cogeneration; Microturbines and Small Turbomachinery; Oil and Gas Applications; Wind Turbine Technology ◽

10.1115/gt2010-23453 ◽

2010 ◽

Author(s):

A. E. Robinson ◽

H. H.-W. Funke ◽

P. Hendrick ◽

R. Wagemakers

Keyword(s):

Combustion Chamber ◽

Gas Turbine ◽

Mass Flow ◽

Gas Turbines ◽

High Energy ◽

High Energy Density ◽

Energy Output ◽

Experimental Investigations ◽

Small Scale ◽

Micro Scale

For more than a decade up to now there is an ongoing interest in small gas turbines downsized to micro-scale. With their high energy density they offer a great potential as a substitute for today’s unwieldy accumulators, found in a variety of applications like laptops, small tools etc. But micro-scale gas turbines could not only be used for generating electricity, they could also produce thrust for powering small unmanned aerial vehicles (UAVs) or similar devices. Beneath all the great design challenges with the rotating parts of the turbomachinery at this small scale, another crucial item is in fact the combustion chamber needed for a safe and reliable operation. With the so called regular micromix burning principle for hydrogen successfully downscaled in an initial combustion chamber prototype of 10 kW energy output, this paper describes a new design attempt aimed at the integration possibilities in a μ-scale gas turbine. For manufacturing the combustion chamber completely out of stainless steel components, a recuperative wall cooling was introduced to keep the temperatures in an acceptable range. Also a new way of an integrated ignition was developed. The detailed description of the prototype’s design is followed by an in depth report about the test results. The experimental investigations comprise a set of mass flow variations, coupled with a variation of the equivalence ratio for each mass flow at different inlet temperatures and pressures. With the data obtained by an exhaust gas analysis, a full characterisation concerning combustion efficiency and stability of the prototype chamber is possible. Furthermore the data show a full compliance with the expected operating requirements of the designated μ-scale gas turbine.

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