Maintenance work on Unit 2 at the Merom Generating Station includes use of a ‘Gecko’ that can scale walls
EnergyLines April 2018
This robotic ‘gecko’ is scanning the tubes within the boiler at the Merom Generating Station during scheduled maintenance taking place this spring.
The purpose of the maintenance is to prepare for summer demand. Projects like this connect
to Hoosier Energy’s mission to provide members with assured, reliable and competitively priced energy and services in a safe and environmentally acceptable manner.
Unique to this year’s scheduled maintenance is the use of advanced technology in the boiler. A robot termed the ‘Gecko’ climbs the boiler tubes. The robot, developed by Gecko Robotics, attaches to the tubes by using high-strength rare Earth magnets.
It crawls up the side of the wall at a rate of about six inches per second. The Gecko is able to take ultrasonic thickness measurements every inch on eight boiler tubes at a time.
The robot can travel in all directions allowing for safe access to hard-to-reach areas inside the boiler. For each tube, approximately 36 data points are captured for every foot traveled.
The Merom Generating Station is using the technology to monitor corrosion. Data collected shows where tubes have thinned and where a tube leak might occur. This data is output as a map.
The red areas on the data map indicate a thin wall of the tube, which will be repaired. The green color indicates areas that are in acceptable condition. Information collected provides the tube number and elevation showing teams exactly where repairs are needed.
“In order to produce reliable and economic electricity for our members, it’s important that we stay on top of tube leaks and frequently monitor the condition of the water walls [tubes] to prevent tube leaks,” said Senior Power Production Engineer for Hoosier Energy Luke McKinney.
“The utilization of the technology that Gecko Robotics has developed helps us quickly identify and properly prioritize areas that require repairs or replacements. The new technology takes approximately 132 times more data than traditional inspection methods in the same four-day inspection period,” McKinney added.
At the end of the inspection, the data is compiled and a map is developed, which records the lowest thickness readings for each foot of boiler tubing.
McKinney uses the thickness reading data to direct repairs, which can include boiler makers performing weld metal buildup on some areas, tube replacement on others, and in some cases, spraying a ceramic coating on the tubes to avoid future corrosion.