Antonio Vallejo ��lvarez: arquitectura de la sensatez

La presente tesis doctoral desarrolla la obra del arquitecto Antonio Vallejo ��lvarez (n. 1903, t. 1928, f. 2002) cuya larga carrera profesional permite observar una evoluci��n que tiene como fondo la de la arquitectura espa��ola desde los planteamientos academicistas de principios del siglo XX, pasando por el primer racionalismo, hasta la influencia del Movimiento Moderno. Antonio Vallejo naci�� en Almonacid de Zorita, un pueblo de la provincia de Guadalajara peque��o pero singular ya que entonces se constru��a el Salto de Bolarque, instalaci��n energ��tica crucial en la ��poca que albergaba adem��s elementos de arquitectura culta. La familia le envi�� a Madrid a estudiar en las Escuelas P��as de San Fernando y luego en la vieja escuela de arquitectura de la calle Escritorios perteneciente a la Real Academia de Bellas Artes de San Fernando. Terminada la carrera realiz�� unas primeras edificaciones de corte historicista con relativa abundancia de estilemas academicista que van desapareciendo paulatinamente a la vez que evolucionan hacia el ���dec�����. De esta depuraci��n, que puede observarse muy bien en los n��meros 69,73 y 62 de la calle Viriato de Madrid, resulta un primer racionalismo en el que las balconadas y cuerpos volados se apoyan sobre una trama racionalista ortogonal cada vez m��s r��gida. Simult��neamente trabaj�� en esta ��poca en la Oficina de Informaci��n sobre la Ciudad del Ayuntamiento de Madrid junto a Bernardo Giner de los R��os y Fernando Garc��a Mercadal, entre otros. M��s tarde se incorpor�� a las ��rdenes del primero a la Oficina de Construcciones escolares donde se mantuvo hasta el estallido de la guerra civil. Al amparo de la Ley Salm��n fund�� la empresa promotora de viviendas Ar-In donde realiz�� una arquitectura en la que la trama racionalista cobra una gran fuerza expresiva, matizada y potenciada por grandes balcones aterrazados de corte higienista. Sus exponentes m��ximos son el conjunto en la calle Narv��ez esquina a Alcalde S��inz de Baranda, y la manzana de Guzm��n el Bueno, 75 de Madrid. La guerra civil interrumpe el proceso y tras ella nuestro autor ensaya la supervivencia del racionalismo mediante la superposici��n de la trama en grandes cuerpos de alzado de ladrillo ocupando las plantas de pisos, sobre un basamento de granito en la planta baja y una especie de p��rtico enmarcando los huecos del ��tico a modo de remate. En las ventanas se colocan embocaduras de caliza de diversas formas. Esta arquitectura, muy en la l��nea del gusto de la ��poca, ser�� sublimada mediante un magn��fico ejemplo de manierismo en su gran obra de la Residencia de los Agustinos Recoletos y la Iglesia de Santa Rita de Madrid. Superados los al menos tres lustros de postguerra, Vallejo inicia un proceso que podr��amos llamar estructuralista en la medida en que la asunci��n de la situaci��n de la estructura en el edificio y el m��dulo por ella creada definen sus caracter��sticas formales. Aqu��, tras trabajar el hormig��n armado en algunos edificios como los del Residencial Bellas Vistas de Madrid, lo hace con mucho m��s convencimiento en edificios con estructuras de acero como el colegio del Sagrado Coraz��n de Guadalajara. Es tambi��n importante hablar de la provincia de Almer��a, a cuya capital llega nuestro arquitecto inmediatamente despu��s de la guerra civil para alejarse de las indeseables consecuencias que hubiera podido tener su fidelidad al gobierno de la Rep��blica con el que colabor�� hasta el ��ltimo momento. En la ciudad desarroll�� una extensa labor como constructor a trav��s de Duar��n SA, que se hab��a formado sobre los restos de su promotora. Tambi��n como arquitecto, con una labor paralela a la madrile��a pero con menor presi��n ambiental, lo que contribuy�� a que en cierta medida el proceso de afloramiento de su arquitectura estructuralista, heredera lejana de su primer racionalismo, fuese m��s r��pido, como prueban realizaciones como los edificios de la calle Juan P��rez, 18 y del Paseo de la Estaci��n, 19. ABSTRACT This thesis deals with the works in architecture from Antonio Vallejo ��lvarez (b. 1903, g. 1928, d. 2002) whose long career enables us to concentrate on the evolution of the Spanish Architecture from the Academicism taking place at the beginning of XXth century , until the influence of the Modern Movement, taking also into account Racionalism. Antonio Vallejo was born in Almonacid de Zorita, a village in the province of Guadalajara small but unique because then Salto de Bolarque the crucial energy facility at the time also housed elements of classical architecture is built. His family sent him to study to Madrid in Escuelas P��as de San Fernando first, and then he attended lessons in the old Architecture school from Escritorios street belonging this last one to la Real Academia de Bellas Artes de San Fernando. Once he finished his degree on Architecture, he worked on some historicist buildings with a great use of academicist stylemes which will be disappearing little by little, turning into ���deco���. From this depurationn, whose traces can be found in 69, 73, 62 at Viriato street in Madrid, our architect ends up with a first racionalism in which balconies and flown bodies are suspended on a racionalist and orthogonal more and more rigid. At that time, he was also working in the Information Office in Madrid Town Hall together with Bernardo Giner de los R��os y Fernando Garc��a Mercadal, among others. Later, he worked for Bernardo Giner de los R��os in the School Building Offices until the breaking out of the Civil War. Under Salm��n law, he founded a developer for buildings named Ar-In, where he developed a type of Architecture in which racionalism develops a magnificent expressive force, empowered by great terraced balconies with higienistain court. His great masterpieces at this time are the buildings from Narvaez opposite to Alcalde S��inz de Baranda and the block in 75 Guzm��n El Bueno, in Madrid. Civil war interrupts somehow his process and once the war is over, our architect works on the survival of racionalism by overlapping on large bodies of brick elevation occupying different floor plants, on a base of granite on the ground floor and a sort of portico framing the gaps in the attic by way of auction. On the Windows he se colocan embocaduras de caliza de diversas formas. This type of architecture, very much enjoyed at that time, will be sublimed as a great example of manierism in his great work such as the case of Agustinos Recoletos Residence and Santa Rita Church in Madrid. About fifteen years after the war, in the post-war era, Vallejo starts a process which we could call structuralist, as lons as the asumption from the situation of the structure in the building and the created module define his main features. Here, once our architect works with reinforce concrete in some of his buildings such as Residencial Bellas Vistas de Madrid, he improves his technique with steel strucutres such as the on in the school Sagrado Coraz��n in Guadalajara. It is also remarkable to speak about the province of Almer��a, where our architect arrives inmediately after the civil war, to get rid of the consequences of his loyalty to the Republic movement to which he collaborated until his death. He developed a great career as a builder there through Duar��n SA, which was launched though his former enterprise. Similary as the way he worked in Madrid,he, also as an arquitect, did his work in Almer��a with less environmental pressure though, fact which contributed to the flourishing of the structuralist architecture, as an heir from his first racionalism, as it can be shown from buildings in streets such as 18 Juan P��rez, and 19 Paseo de la Estaci��n.

Fresnel-based modular solar fields for performance/cost optimization in solar thermal power plants: A comparison with parabolic trough collectors.

Linear Fresnel collectors are identified as a technology that should play a main role in order to reduce cost of Concentrating Solar Power. An optical and thermal analysis of the different blocks of the solar power plant is carried out, where Fresnel arrays are compared with the most extended linear technology: parabolic trough collectors. It is demonstrated that the optical performance of Fresnel array is very close to that of PTC, with similar values of maximum flux intensities. In addition, if the heat carrier fluid flows in series by the tubes of the receiver, relatively high thermal efficiencies are achieved. Thus, an annual solar to electricity efficiency of 19% is expected, which is similar to the state of the art in PTCs; this is done with a reduction of costs, thanks to lighter structures, that drives to an estimation of LCOE of around 6.5 c���/kWh.