Penetration of Refractory Metals by Alkali Metals

Klueh, R.L.

doi:10.1007/978-1-4684-1845-3_11

Cited by 11 publications

(2 citation statements)

References 4 publications

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“…If the exotic and expensive are eliminated this leaves the refractory metals: W, Nb, Ta, Mo, and Zr and their alloys; some of which have substantially higher creep strength than Ni-Cr alloys [30,31]. Refractory metals can also exhibit resistance to corrosion by liquid alkali metals [32]. Furthermore, the poor oxidation resistance of refractory metals due to their volatile oxides [33,34] is not a limitation if reducing conditions are maintained.…”

Section: Metal Vapor Gas 'I\irbinesmentioning

confidence: 99%

Chemical Looping Combustion Using the Direct Combustion of Liquid Metal in a Gas Turbine Based Cycle

McGlashan

Childs

Heyes

2010

Journal of Engineering for Gas Turbines and Power

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A combined cycle gas-turbine generating power and hydrogen is proposed and evaluated. The cycle embodies chemical looping combustion (CLC) and uses a Na based oxygen carrier. In operation, a stoichiometric excess of liquid Na is injected directly into the combustion chamber of a gas-turbine cycle, where it is burnt in compressed O2 produced in an external air separation unit (ASU). The resulting combustion chamber exit stream consists of hot Na vapor and this is expanded in a turbine. Liquid Na20 oxide is also generated in the combustion process but this can be separated, readily, from the Na vapor and collects in a pool at the bottom of the reactor. To regenerate liquid Na from Na20. and hence complete the chemical loop, a reduction reactor (the reducer) is fed with three streams: the hot Na20 from the oxidizer, the Na vapor (plus some entrained wetness) exiting a Na-turbine, and a stream of solid fuel, which is assumed to be pure carbon for simplicity. The sensible heat content of the liquid Na20 and latent and sensible heat of the Na vapor provide the heat necessary to drive the endothermic reduction reaction and ensure the reducer is externally adiabatic. The exit gas from the reducer consists of almost pure CO, which can be used to generate byproduct H2 using the water-gas shift reaction. A mass and energy balance of the system is conducted assuming reactions reach equilibrium. The analysis allows for losses associated with turbomachinery; heat exchangers are assumed to operate with a ßnite approach temperature. However, pressure losses in equipment and pipework are assumed negligible-a reasonable assumption for this type of analysis that will still yield meaningful data. The analysis conflrms that the combustion chamber exit temperature is limited by both first and second law considerations to a value suitable for a practical gas-turbine. The analysis also shows that the overall efficiency of the cycle, under optimum conditions and taking into account the work necessary to drive the ASU, can exceed 75%.

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Section: Metal Vapor Gas 'I\irbinesmentioning

confidence: 99%

Chemical Looping Combustion Using the Direct Combustion of Liquid Metal in a Gas Turbine Based Cycle

McGlashan

Childs

Heyes

2010

Journal of Engineering for Gas Turbines and Power

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“…In this respect, according to the predictions of world-famous scientific-research centers specializing in the field of reactor materials science, the application of refractory metals, in particular, vanadium and low-alloyed vanadium alloys (up to 15 at. %) [9][10][11][12], nickel-based alloys, and special steels [3,9], is gaining in importance. The advisability of using vanadium is due to the optimum complex of physicomechanical properties and its compatibility with nuclear fuel and high corrosion resistance in promising high-temperature, heat-transport media (helium, lithium, and sodium melts).…”

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confidence: 99%

Methods of improving the high-tempera ture strength and corrosion resistance of vanadium and certain alloys used in reactors

Широков¹

1999

Mater Sci

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We present new evidence for the high-temperature strength of vanadium and low-alloyed (up to 15 at. %) vanadium-based alloys under conditions of prolonged (up to 5000 h) high-temperature (973-1173 K) exposure to vacuum, helium, lithium and sodium melts, modeling reactor heat-transport media (10 Pa). The kinetics of phase transformations in alloys of the systems V-Zr-C, V-Nb-Zr-C, V-Mo-Zr-C, and V-Ti-O in the process of prolonged aging under stress is analyzed. It is established that the process of pre-decay of a solid solution has many stages and is intensified by the action of stresses. The corresponding isothermal diagrams of the decay of VTsU (V-Zr-C) alloy are constructed. We give recommendations as to the choice of alloying elements with the aim of enhancing the high-temperature strength of vanadium and vanadium alloys used for reactors. New alloys developed on the basis of the systems V-Ti-O, V-Nb-Zr, V-Ta-Hf, V-Cr-Sc, and V-Cr-Nd and a new method of hardening thermochemical treatment of vanadium-titanium alloys with the use of oxygen from air have found application in pilot-engineering developments for high-temperature nuclear power plants.The strategy of the development of power engineering consists of increasing the power of existing nuclear reactors, transferring to the use of the energy of fast neutrons, bringing controlled thermonuclear fusion to a commercial level, and increasing the safety margin of energy production to the maximum possible extent [1][2][3]. The analysis of the principles of selection of materials for the operating and promising fast-neutron nuclear power plants and for fusion-type reactors shows that one of the methods of upgrading their efficiency consists of raising the operating temperatures of the processes of energy conversion and transmission up to 900-1400 K and using unconventional high-temperature media. The experience in the operation of reactors and the predictions of many scientists allow one to separate the following promising media [4][5][6][7][8][9]. For fast-fission reactors, these are heat-transport media based on sodium, helium, and, in some cases, on lithium. For fusion-type reactors, we mention lithium (blanket), eutectics (tritium-reducer), helium (heat-transport medium), and vacuum (vacuum wall). For this to be realized, the development of new materials and the improvement of the reliability and serviceability of tested high-temperature metallic materials are required. These materials should meet the requirements of not only the physics of nuclear fission and lusion, but also the physicochemical requirements that are imposed by their prolonged interaction with reactor media and related ones under the simultaneous action of high temperature and loads. In this respect, according to the predictions of world-famous scientific-research centers specializing in the field of reactor materials science, the application of refractory metals, in particular, vanadium and low-alloyed vanadium alloys (up to 15 at. %) [9][10][11][12], nickel-based alloys, and special steels [...

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A Review of the Chemical, Physical, and Thermal Properties of Lithium that are Related to its Use in Fusion Reactors

Cairns

Cafasso

Maroni

1972

The Chemistry of Fusion Technology

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Penetration of Refractory Metals by Alkali Metals

Cited by 11 publications

References 4 publications

Chemical Looping Combustion Using the Direct Combustion of Liquid Metal in a Gas Turbine Based Cycle

Chemical Looping Combustion Using the Direct Combustion of Liquid Metal in a Gas Turbine Based Cycle

Methods of improving the high-tempera ture strength and corrosion resistance of vanadium and certain alloys used in reactors

A Review of the Chemical, Physical, and Thermal Properties of Lithium that are Related to its Use in Fusion Reactors

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