Techniques for Enhancing Durability and Equivalence Ratio Control in a Rich-Lean, Three-Stage, Ground Power Gas Turbine Combustor
This effort summarizes the work performed under Task IV, Sector Rig Tests of the CRT - Critical Research and Support Technology Program, a Department of Energy funded project. The rig tests of a can-type combustor were performed to demonstrate two advanced ground power engine combustor concepts: steam cooled rich-burn combustor primary zones for enhanced durability; and variable combustor geometry for three stage combustion equivalence ratio control. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This offers the potential of both long life and reduced use of strategic materials for liner fabrication. Three degrees of variable geometry were successfully implemented to control airflow distribution within the combustor. One was a variable blade angle axial flow air swirler to control primary airflow while the other two consisted of rotating bands to control secondary and tertiary or dilution air flow.Copyright © 1982 by ASME
Literature survey of properties of synfuels derived from coal
A literature survey of the properties of synfuels for ground-based turbine applications is presented. The four major concepts for converting coal into liquid fuels (solvent extraction, catalytic liquefaction, pyrolysis, and indirect liquefaction), and the most important concepts for coal gasification (fixed bed, fluidized bed, entrained flow, and underground gasification) are described. Upgrading processes for coal derived liquid fuels are also described. Data presented for liquid fuels derived from various processes, including H-coal, synthoil, solvent refined coal, COED, donor solvent, zinc chloride hydrocracking, co-steam, and flash pyrolysis. Typical composition, and property data is also presented for low and medium-BTU gases derived from the various coal gasification processes.
Recent developments in actuators: GTO and related devices
Abstract In addition to the established silicon devices for power switching and motor control, the bipolar transistors and the thyristors, new devices such as power field-effect transistors, gate-turn-off thyristors (GTO) and integrated power devices have been developed in recent years. Power MOS field-effect transistors allow very fast switching with low control power, because they have no stored charge. Their on-state resistance, however, is very high in high voltages devices. Bipolar transistors with high volatge capability have low current gain at high current densities, mainly because of recombination of the stored charge in the emitter layers. GTO thyristors do not suffer from these effects, so they can be designed for very high voltages. Though they need high turn-off current gate pulses, GTO circuits are simpler and, in many applications, more economical than thyristor circuits, because the commutation circuit can be omitted. A short comparative description of these devices is given, and the GTO is described in greater detail. As an important example for power device integration, developments of optothyristors (or optotriacs) are shown which will result in simplified solid-state relay technologies.