Slagging MHD generator: a parametric study

Technical Report · Sat Jan 01 00:00:00 EST 1977

OSTI ID:5213068

Taylor, J G

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
• Resource Relation: Other Information: From 17. symposium on engineering aspects of MHD; Stanford, CA, USA (27 Mar 1978). Portions of document are illegible
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
COAL-FIRED MHD GENERATORS
MHD CHANNELS
FLOW MODELS
SLAGS
BOUNDARY CONDITIONS
BOUNDARY LAYERS
CALCULATION METHODS
COMBUSTION PRODUCTS
EQUATIONS
INTERFACES
LAYERS
MATHEMATICAL MODELS
VAPOR CONDENSATION
DIRECT ENERGY CONVERTERS
MHD GENERATORS
300104* - MHD Generators- Duct Engineering & Fluid Dynamics