Examinando por Autor "Plana, Daniel"

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Acceso Abierto
Coatings for Oxycombustion - Supercritical Steam Boilers Components
(University of Hakodate, 2014-01-21) Agüero, Alina; Baraibar, Ignacio; González, Vanessa; Gutiérrez del Olmo, Marcos; Muelas Gamo, Raúl; Plana, Daniel
[1] CO2 Capture Technologies: Oxi Combustion with CO2 Capture, Global CCS Institute, Palo Alto, CA, January 2012 http://www.globalccsinstitute.com/publications/co2-capture-technologies-oxy-combustion-co2-capture [2] Production of Coatings for New Efficient and Clean Coal Power Plant Materials (POEMA), FP7 Program, G.A. No.: 310436, 2013-2016. [3] Agüero A., González V., Gutiérrez M., Knödler R., Muelas R. and Straub S., Comparison between Field and Laboratory Steam Oxidation Testing of Aluminide Coatings on P92, Materials and Corrosion, Vol. 62 (2011), pp. 561-568 [4] Agüero A., González V., Gutiérrez M. and Muelas R., Oxidation under pure steam: Cr based protective oxides and coatings, Surface and Coatings Technology, 237 (2013) 30-38 [5] Agüero A., Progress in the Development of Coatings for Protection of New Generation Steam Plant Components, Energy Materials, 3 (2008) 35-44 [6] R. Muelas and A. Agüero, INTA, unpublished results.
Restringido
Corrosion Resistance of Novel Coatings on Ferritic Steels for Oxycombustion–Supercritical Steam Boilers: Preliminary Results
(Springer Nature Link, 2015-07-23) Agüero, Alina; Baraibar, Ignacio; González, Vanessa; Muelas Gamo, Raúl; Plana, Daniel; European Commission; Ministerio de Economía y Competitividad (MINECO)
Increasing the efficiency of coal fired steam power plants is an important contribution towards clean coal power. In fact, new ferritic steels are expected to withstand 325 bar and 650 °C. Moreover, in order to facilitate CO2 capture oxygen can be used instead of air for combustion (oxycombustion) so that no NOX emissions are produced. Boiler components, such as superheater tubes, are exposed to both steam and fireside corrosion and at higher temperatures, ferritic steels corrode at very fast rates under both atmospheres. A solution can be found in the use of protective coatings, a number of which, applied by techniques capable of depositing said coatings both on the inner and outer surfaces of tubes, are being studied within nationally and European funded projects. In particular, two new Ni and Cr modified aluminide coatings deposited on P92 by non-line-of-sight hybrid processes have been produced and the preliminary results of on-going laboratory testing, both under oxycombustion model atmospheres as well as under pure steam at 650 °C are promising, in particular those exhibited by the Cr enriched aluminide coating. Moreover, results obtained in a pilot oxycombustion boiler operated by CIUDEN in Leon, Spain are also shown.
Restringido
Laboratory corrosion testing of coatings and substrates simulating coal combustion under a low NOx burner atmosphere
(Wiley online library, 2013-07-02) Agüero, Alina; Gutiérrez del Olmo, Marcos; Muelas Gamo, Raúl; Plana, Daniel; Román, A.; Hernández, M.
It is certainly a difficult task to evaluate new materials and coatings to be used for boilers in power plants, as conditions are extremely complex, comprising a highly erosive environment, high temperature, highly corrosive gases, and reactive deposits. In particular, early catastrophic failures, as well as higher degradation rates have been observed on different power plant boiler components when operating under atmospheres containing low levels of oxygen. These atmospheres are typical of low NOx burners, and can be more corrosive than normal oxidizing conditions. The presence of a sulfidizing atmosphere as well as ash deposits present in boilers, are in part responsible of this accelerated damage. In this work, testing under a low oxygen atmosphere has been carried out on T22 and P92 uncoated and coated specimens. The atmosphere was equal to that measured in a Spanish coal-fired power plant (ENDESA, Compostilla, León) and the test temperature was 580 °C. Tested coatings were slurry applied aluminides, as well as two HVOF sprayed coatings including a commercially deposited Cr2C3NiCr, and a newly developed Cr2O3-Cr composite coating. The specimens were covered with ash (taken from the plant) prior to testing. After testing, the uncoated substrates exhibited high thickness oxides with some sulfide inclusions whereas all tested coatings were very protective. Exposed samples of T22 tubes employed in the Compostilla power plants were analyzed and compared with the corresponding specimens tested in the laboratory. In both cases, the scales contained Fe3O4 and FeS but the sulfide content was significantly higher in the scale formed in the plant. Moreover, ash particles were found embedded in the both scales.