Design and construction of a lNG storage tank in Huelva, Spain

Abstract

This issue contains a number of articles; contents of which are summarized below, giving an overall idea of this outstanding engineering accomplishment. The National Gas Scheme intends to duplicate the consumption of natural gas during the period 1985-1992 to reach 6 % participation in the provision of primary energy by 1992. It is essential a great effort to meet the requirements of this scheme. Among the activities included in the Scheme, we shall mention the construction of a LNG Terminal at Palos de la Frontera, Huelva, Spain, with the singular first 60,000 cubic meter net capacity LNG Storage Tank. Design, construction and commissioning of the tank was made on a turn-key basis to only one contractor who assumed the overall responsibility with fixed cost and completion date. The project was awarded to the Joint Venture ENTRECANALES Y TAVORA, S. A. and SOCIETE NOUVELLE CONSTRUCTIONS METALLIQUES DE PROVENCE The important coordination effort and the Work conducted by an homogeneous and integrated team have resulted in the fulfillment of quality requirements on the specified dates. The storage tank is a self-supporting structure of steel concrete double wall type. The design conforms to rigid project requirements and location conditions. Among the design parameters it should be remarked the infernal temperature of —170 °C, Boil-off 0,05%, Seism 0,28 g OBE and 0,34 g SSE, Burn-out 72 h, Impact 2,000 kg. at 50 m/s, etc. The external concrete tank, doubly post-tensioned is composed of a slab made in two stages to free from movement the cylinder wall which is concreted in layers using slipforms. It is topped with a spherical dome that was concreted on a steel liner that was erected on the foundation slab and then raised to position by compressed air. The inner container, 9 % Ni steel, is erected by introducing the prefabricated and previously curved plates inside the external tank. They are then placed into position and welded with the assistance of motor cars and automatic (welding equipment) that run on a rail anchored to the dome. The Quality Assurance organization integrated all activities and on the basis of the applicable regulations, it has prepared specifications and detail procedures. The material used was characterized through homologation and control tests, with verification and determination of physical properties of such materials at cryogenic temperatures. The tests were conducted at specialized laboratories under the coordination of the IBERINSA Construction Materials Laboratory under the direction of Professor Elices. The experience and results obtained have permitted a discussion of the essential aspects of the Prescriptions developed by KELLOGG suggesting alternates to his most conflictive items.