Background

Mae Moh power plant consists of 10 generating units, i.e. Units 4-13 (Units 1-3 were decommissioned from operation). Having a production capacity of 2,400 MW, the Mae Moh Power Plant can supply 50% of the electricity to the northern area, 30% to the central area, and 20% to the northeastern area of Thailand. The fuel consumption is approximately 16 million tons yearly. Electricity Generating Authority of Thailand (EGAT) had planned to replace the expired 600 MW Units 4-7 of Mae Moh Power Plant, which were in operation for 33 years, with new units using modern and higher efficiency technology. The new plant would use less volumes of coal, have low level of emissions and on completion it would well serve the ever-increasing electricity demands. The Project was awarded to a joint-venture between Alstom Power System SA from France, Alstom (Thailand) Ltd. and Marubeni Corporation (Note that GE Power acquired Alstom after the award)

Operating Process

Units 4-7 Replacement Project covers an area of 63 Rai of Mae Moh Power Plant. The new plant uses indigenous lignite as main fuel and is equipped with supercritical pressure steam generation to obtain higher efficiency, resulting in less fuel use and therefore less carbon dioxide emission. Furthermore, the plant is equipped with a Flue Gas Desulfurization (FGD) System, Low NOx Burner System, Electrostatic Precipitator (ESP) System, and the new Selective Catalytic Reduction (SCR) System. The SCR reduces the nitrogen oxide emissions, thus helps effectively control the environmental impact.

Special Requirements

The rubber lining was selected was a self-vulcanizing black rubber lining based on Bromobutyl Rubber (BIIR). The material was applied to site erected steel tanks and cured at ambient temperatures. This option was recommended compared to workshop applied rubber lining as damages may occur to rubber lined tanks during transport to site.

Corrosion / Wear Protection

The tanks that the rubber lining was applied to required protection to constant immersion, abrasion media, erosion and high temperature and pressure. This rubber lining was recommended to achieve protection and with the thickness applied, can provide long term protection to realize the lifetime service goal of the project.

Lining System Specification

The 4 – 6 mm pre-cured Bromobutyl rubber sheet was applied to all surfaces including tank walls, ceilings, 2 layers on floors and 2 meters up the walls and 2 layers on the baffles. A hard rubber plate was used on manhole and nozzle flange faces. These rubber lining system was applied to the Purge, Auxiliary Storage, Equalization, Reclaimed Water and Local Gypsum Slurry Tanks, Air Receivers, Hydro-Cyclone Primary Pipes and Hydro-Cyclone Secondary Repairs.

Project Details

Location	Lampang, Thailand
Project	Mae Moh Power Plant: MMRP1 – Units 4-7 Replacement Project
Owner	Electricity Generating Authority of Thailand (EGAT)
EPC	Alstom-Marubeni Consortium (AMC)
Date	2017 – 2018
Work	Tanks,Pipes & Repair Work
System	Self-Vulcanizing Rubber Lining
Area	4,500 m2
Value	US$ 700,000