Oxidation and sulfidation behavior of Fe-20Cr-16Ni-4Al-1Y2O3 oxide-dispersion-strengthened alloy

Malik, Arshi; Natesan, K.

doi:10.1007/bf00664428

Cited by 9 publications

(1 citation statement)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The entrapped or absorbed dispersoid reduces diffusion of cations through the scale with oxide growth taking place at the scale-metal interface by exclusive inward oxygen transport with minimal growth stresses from alumina nucleation within the existing scale (Quadakkers, 1989). The presence of yttrium at the scale grain boundaries retards grain boundary migration resulting in fine grain scales where growth stress are more effectively relieved by diffusional plastic flow improving scale adherence (Malik, 1990). Quadakkers (1990) and Versaci et al (1993) have shown that the Kp values vary with exposure time.…”

Section: -4mentioning

confidence: 99%

Combustion 2000

Levasseur¹,

Goodstine²,

Ruby³

et al. 2001

View full text Add to dashboard Cite

. The objective of this report is to emphasize the results and achievements of the program and not to archive every detail of the past six years of effort. These details are already available in the twenty-two quarterly reports previously submitted to DOE and in the final report from Phase I. The report is divided into three major foci, indicative of the three operational groupings of the program as it evolved, was restructured, or overtaken by events. In each of these areas, the results exceeded DOE goals and expectations.HIPPS Systems and Cycles (including thermodynamic cycles, power cycle alternatives, baseline plant costs and new opportunities) HITAF Components and Designs (including design of heat exchangers, materials, ash management and combustor design)Testing Program for Radiative and Convective Air Heaters (including the design and construction of the test furnace and the results of the tests)There are several topics that were part of the original program but whose importance was diminished when the contract was significantly modified. The elimination of the subsystem testing and the Phase III demonstration lessened the relevance of subtasks related to these efforts. For example, the cross flow mixing study, the CFD modeling of the convective air heater and the power island analysis are important to a commercial plant design but not to the R&D product contained in this report. These topics are of course, discussed in the quarterly reports under this contract.The DOE goal for the High Performance Power Plant System ( HIPPS ) is high thermodynamic efficiency and significantly reduced emissions. Specifically, the goal is a 300 MWe plant with > 47% (HHV) overall efficiency and ≤ 0.1 NSPS emissions. This plant must fire at least 65% coal with the balance being made up by a premium fuel such as natural gas.To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine.The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 °F (1260-1371 °C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. ivThe UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by t...

show abstract

Section: -4mentioning

confidence: 99%