Construction Update

Tuesday, 9 September 2014

Draught Group Test Run commenced

Each boiler is equipped with two draught groups, consisting of an axial flow forced draft (FD) fan, a radial flow primary air fan and an axial flow induced draft fan. The forced draft fan supplies air to the furnace while the primary air fan is used to supply air for drying and conveying the pulverised fuel into the furnace. The induced draft fan draws the products of combustion from the furnace via the steam superheaters, reheaters, economiser, air preheater and fabric filter plant. The induced draft (ID) fans then exhaust the combustion gases to the chimney.

The Draught Group Test run commenced on Sunday, 07 September 2014 and is due to run for approximately 12 days. The purpose of the draught group test run is to test:

The ID, FD and air sub-group start sequence, individually.

The complete draught group, group start-up sequence.

The purge program.

Basic optimization of windbox and furnace pressure control.

Boiler purging is a process to eliminate the risk of explosion in the boiler during boiler start-up by removing any gasses out of the boiler that might contain unburnt fuel particles. The process is carried out before fire can be put in to the boiler. The testing of the fans and the purge program will be executed by the Alstom DCS and the boiler protection system monitors and determines the success of the Draught Group Test run.

Above illustration the Boiler Purging process

Chimney

FD Fan

ID Fan

PA Fan

PA Fan Air Heater

Air Heater

ID Fan

Construction Update

Gas Air Heater

Forced Draught Fan

PA Fan

Boiler – Cladding progress

ID Fans and PJFF

Pulse Jet Fabric Filter Hopper

Construction Update

Please Ctrl-click on the following link to view a video clip covering construction activity at Unit 6 or copy and paste it into your Web-browser:

http://medupiproject.eskom.co.za/videos/Sept2014Update.mp4

The Site Integration Tests (SIT) for PI6 and BOP were successfully completed. The accomplishment of this significant milestone for the C&I Control systems means that the Distributed Control System is now ready to support First Fires and Synchronisation.

“The Site Integration Test (SIT) refers to the validation and verification of the Distributed Control System (DCS) as an integrated unit after delivery and installation on site. The verification of communication to any third party systems also forms an integral part of the SIT. As a fully integrated Factory Acceptance Test (FAT) had never taken place, the SITs were the first integrated tests of the complete Medupi DCS.

The SER DCS SIT was conducted between 28 July 2014 and 7 August 2014, releasing the SER DCS for use during commissioning. The PI6 (Unit 6) DCS SIT and BOP DCS SIT were conducted in parallel shortly after completion of Chemical Clean, from 25 August 2014 to 5 September 2014. All three DCS SITs were successfully completed and signed off on 5 September 2014 with the submission of all the relevant documentation.

The SITs included, but were not limited to:

Verification of the DCS reliability and availability with individual and concurrent DCS equipment failures present,

Ensuring the correct performance and functioning of the integrated systems that make up the Medupi DCSs,

Verification of third party system interfaces, e.g. the Auxiliary Boiler, the Turbine Control and Protection System, the Boiler Protection System, etc.

The DCS SIT is an important part of proving the DCS readiness and the integrity of the system prior to process plant commissioning.

Site Integration Tests (SIT) for PI6 and BOP successfully completed

Construction Update

Commissioning is progressing steadily towards 1st Syncronization of Medupi Unit 6

Construction Update

Alstom has commenced work to align the suction pipe line of the CEP pumps at the Air Cooled Condenser Condensate tank (ACCCT) building.

Wind cross foundation on Grid Line 37 to 39 is ready for handover to Alstom for erection of the steel structure.

Erection of the Condensate Reserve Tank is now complete. The next phase is the execution of the hydro test.

6.6kV boards ringing out are progressing well.

Unit 5

Construction Update

Unit 4

Unit 4 transformer bay data books were issued on completion of the civil works. The transformers will be installed during 12 – 14 September 2014.

Unit 4 transmission line cantilever installation is in progress. Stringing will follow on completion.

Unit 4 lube oil tank and oil coolers were placed into position in the lube oil room. Pipe work installation will follow.

Unit 3

Unit 3 Air Cooled Condenser Condensate tank (ACCCT) installation on top of the building is complete. The Condensate pipe installation can now proceed.

Unit 3 Turbine House 6.6m Level Q-deck installation has started in preparation for the concrete to be poured.

UNIT 4 & 3

Construction Update

ACC Unit 1 ESD CU09+CU10 North 41m long (±68 tons) was lifted into position, making a total of 144m installed out of 284m/unit length.

Turbine Hall Unit 1 first roof section was erected.

A total of 83m out of 284m/ unit length of ESD were installed to date.

ACC Unit 2 good production is being achieved on bundle erection, currently 480 bundles out of 640/unit are installed.

Medupi Power Station will comprise of six units with a gross nominal capacity of 800MW each, resulting in a total capacity of 4 800 MW. Construction activities commenced in May 2007, with the first of the six units of the power plant planned for first synchronisation in December 2014. In an effort to improve efficiency of the station, supercritical boilers and turbines are being installed. These operate at higher temperatures and pressures than Eskom’s other stations resulting in reduced need for natural resources, reduced emissions and lower water consumption. This baseload station will also use direct dry-cooling due to the water scarcity in the area and all the water will be re-used in the electricity generation process.

Roman Crookes

Project Director: Medupi Power Station Project

UNIT 2 & 1