Quality assured during Sines thermal power plant upgrade

Lisbon - Energias de Portugal (EDP), one of Europe's major electricity operators, launched a desulphurisation project back in May 2006, with the objective of reducing SO2 in the Sines Thermal Power Plant.

The desulphurisation project had to ensure that the future energy production of the plant was in accordance with the Portuguese law DL178/2003, also known as the LCP Directive, which implements the European Directive 2001/80/EC on the limitation of emissions of certain air pollutants into the air from large combustion plants.

A consortium between Hitachi Ltd. and Cobra Instalaciones y Servicios S.A. was the main subcontractor for this project and was responsible for the turnkey solution for the desulphurization plant engineering, design, construction and implementation, as well as for the initial operations.

The project consisted of four units, one in each of the concerned production groups. The desulphurization facility was installed in the pieces where SO2 neutralisation occurs, as well as in absorbers and in the preparation and storage facilities for plaster.

Highlighting the scale of the project, Alejandro Suárez Serrats, director of the desulphurisation project at the power Plant on behalf of Cobra, said: "There were 800 workers on site, with more than two million working hours. Additionally, we needed a lot of extra resources for support, transport, elevation, etc."

The Hitachi-Cobra Consortium assigned SGS Portugal to manage and supervise all quality-related activities during the whole upgrade process. The award was due to SGS's experience in power generation and in similar desulphurisation projects.

Accordin to SGS, it paid particular attention to the continuous availability of dedicated technical staff for the evaluation of technical conformity with engineering specifications of both materials and equipment used during the entire project.

Throughout the evaluation of technical conformity, continuous quality supervision was implemented during the production of in-line equipment, filters, instrumentation, pipes and plates for several tank assemblies onsite. The quality supervision aimed to avoid failures in future operation caused by poor material quality or wrong choice of material. It also ensured that performance tests of the equipment on manufacturers' premises were carried out before delivery to the plant site.

The SGS team onsite also worked to assure conformity with engineering specifications during project execution. Activities involved among others, mechanical testing, non-destructive testing, pressure equipment certification, equipment licensing and CE Marking.

SGS services during assembling and instrumentation, electrical and automation activities focused on reviewing the subcontractors' specifications, evaluating their conformity with requirements, monitoring the tests, testing the welds, and final commissioning.

The company also provided the Consortium with an entire support team whose job was to calculate and verify equipment and structures under different circumstances of the project assumptions or before changing specifications onsite. The team also assisted in finding proper materials and welding solutions and elaborating corrosion and anti-corrosion plans. In addition, SGS consulted with the competent official authorities and handled all details related to licensing.

The SGS team provided real time information and participated proactively in resolving any difficulties. Project Director Alejandro Suárez Serrats concluded saying: "The collaboration between the Hitachi-Cobra Consortium and SGS came through without any problems. Generally, the Consortium was very pleased with SGS, especially with the importance they gave to quality in this project."