Combustor modified

Experiments are described using premixed prevaporized JP-10 in a dump combustor modified to accommodate counterflow control at the dump plane. The primary benefit of operation under prevaporized conditions is the careful regulation of the JP-lO/air stoichiometry, thereby providing independent assessment of flame speed modification using counterflow technology. Studies were also conducted to evaluate the fundamental nature of a planar nonreacting turbulent countercurrent shear layer. An abrupt transition in flow behavior at a counterflow level of U2/U1 w —0.13 provides the first evidence of global instability in a self-similar turbulent shear layer. 

It is necessary to modify the edge of the hole in various ways to reduce these stress concentrations. Some methods of modification are priming, plunging, and standard radiusing and polishing methods. In the Dry Low NOx Combustors, especially in the lean pre-mix chambers, pressure fluctuations can set up very high vibrations, which lead to major failures. 

Previous data have concerned rmconfined flame configurations driven by velocity perturbations. These cases are less dependent on the geometry because sound generation is not modified by reflection from boundaries. It is also easier to examine rmconfined flames with optical techniques. However, in many applications, combustion takes place in confined environments and sound radiation takes place from the combustor inlet or exhaust sections. The presence of bormdaries has two main effects ... 

Raju, M. S., and W. A. Sirignano. 1990. Multicomponent spray computations in a modified centerbody combustor. J. Propulsion Power 6 97-105. 

Because the initial emphasis of this study was on extending ACC to liquid-fueled combustors, a simple closed-loop controller, which had been well tested in the previous studies involving gaseous fuel, was utilized. Such a controller, however, may not be effective in a combustor where the oscillation frequencies drift significantly with the control. The main problem was the frequency-dependent phase shift associated with the frequency filter. For such a case, it would be more useful to employ an adaptive controller that can rapidly modify the phase setting depending on the shift in the dominant oscillation frequencies. 

The performance of the gas turbine combustor in the Delft PDU with respect to main combustion product formation and fuel NO, was quite well predicted by FLUENT CFD modelling with a modified post-processor, although validation at pressures lower than 0.5 MPa is recommended. 

The Vamamo gas turbine is an almost standard ALSTOM Power Typhoon gas turbine, with modified combustors and burners. In brief, the combustor design is based on the conventional diffusion flame principle. The combustor has contra-rotating primary air and fuel addition to promote good shear layer mixing. In addition, a portion of the fuel is injected through plain holes in the burner head to avoid excessive swirl momentum of the fuel gas. 

The gas turbine installed in the plant is an almost standard Typhoon from ABB Alstom Gas Turbines in Lincoln, England. Modified components are the combustors, the burners and the addition of an air bleed from the compressor, Furthennore, has a special design gas control module been developed to control the product gas, steam and nitrogen to the unit. 

---