Slagging MHD generator: a parametric study
The design and performance of a direct coal-fired MHD generator depends on the effect the liquid slag layer (that forms on the generator walls) has on the fluid dynamic, heat transfer, and electrical characteristics of the generator. This study presents a simplified, self-consistent analysis of the slagging MHD generator. The ultimate goal is to initiate a detailed study of the interaction between the turbulent gasdynamic boundary layer and the condensing slag layer in the presence of electrodynamic forces. The vapor condensation for a laminar boundary layer flow over infinitely segmented Faraday-connected electrodes in the entrance region of the generator is examined. Simply stated, a mixture of a condensible vapor (slag) and a non-condensible gas (seeded coal combustion products) flows through an MHD channel with wall temperatures below the condensation temperature of the vapor. The vapor condenses on the walls creating a liquid slag layer. Vapor condensing at the gas-slag interface carries with it the heat of condensation which is transferred, in part, to the electrodes across the liquid layer. The condensation rate depends on the interface temperature through an equilibrium constraint and the interface shear stress causes slag to flow along the channel walls. In addition, the MHD effects influence the entire system through momentum (Lorentz force) and energy (joule dissipation) considerations. A mathematical model is presented.
- Research Organization:
- Sandia Labs., Albuquerque, N.Mex. (USA)
- DOE Contract Number:
- EY-76-C-04-0789
- OSTI ID:
- 5213068
- Report Number(s):
- SAND-77-1951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
300104* -- MHD Generators-- Duct Engineering & Fluid Dynamics
BOUNDARY CONDITIONS
BOUNDARY LAYERS
CALCULATION METHODS
COAL-FIRED MHD GENERATORS
COMBUSTION PRODUCTS
DIRECT ENERGY CONVERTERS
EQUATIONS
FLOW MODELS
INTERFACES
LAYERS
MATHEMATICAL MODELS
MHD CHANNELS
MHD GENERATORS
SLAGS
VAPOR CONDENSATION