Construction work

Description

I/S REFA (hereinafter ‘REFA’) operates a waste-to-energy combined heat and power plant in Nykøbing Falster, Denmark. Due to the condition of the existing turbine, showing heavy erosion-corrosion damage in its low-pressure parts, as well as reaching the end of its service life, REFA has decided to remove the existing and procure a new steam turbine. The tender concerns a turnkey project including design, manufacturing, delivery, erection, commissioning, testing and one overhaul of a retrofit turbine. Design, manufacturing, delivery, erection, commissioning, testing and one overhaul of a complete retrofit extraction condensing steam turbine including all necessary instrumentation and control to be installed on the existing spring supported main steel frame and integrated into the existing plant. The retrofit turbine is expected to be ready for hand-over in July/August 2021. The delivery includes all piping modification works, inclusive calculation, materials, welding, NDE and pipe support for integration into the existing plant. The turbine will be operated from the central control room and the delivery includes the control and protection system integration into the existing DCS and vibration monitoring system. The delivery includes dismantling of the existing turbine. Civil work for dismantling of the existing turbine or erection of the retrofit turbine is not included. The turbine will receive steam from a waste incineration boiler at approx. 48 bara and 410 C. The casing must have two extractions, the first supplying the deaerator and the second supplying the high-pressure district heat condenser, heating district heating water between 78 C to 89 C. The high-pressure district heat condenser also serves as condenser during plant start-up or during turbine by-pass operation. The steam is exhausted into the low-pressure district heat condenser, receiving district heating water with temperatures varying between 40 C to 60 C. The turbine load range is between approx. 1 MW to full load. At low load operation the boiler can be operated at maximum load, where surplus steam is sent to the high-pressure district heat condenser via the existing turbine bypass. The turbine allows a load change from minimum load to full load within 15 minutes. The retrofit turbine allows to reuse as much of the existing equipment as possible, in particular, gearbox, generator, district heat condensers and deaerator. Reuse of the existing turbine auxiliary equipment, were useful, is possible, but subject to the same requirements, obligations and guarantees as for a new installation. The defects liability period for the equipment within the scope of supply is 2 years. During the liability period any fault or defect of the delivered equipment is mended by the applicant. The turbine is to be designed in accordance with today’s highest technical standards and quality applied to equivalent systems, for a service life of more than 20 years, operating on a very high load for more than 8 000 hours yearly, with an availability of more than 97.5 %. The turbine design should be simple and robust, using adequate material qualities to cope with erosion and corrosion within its wet sections.