South Hedland achieves first-fire milestone
On August 2, TransAlta’s engineer, procurement and construction (EPC) contractor and project team successfully conducted the first fire testing on its simple cycle gas turbine, the first of the three gas turbines installed at the South Hedland power station. This achievement is an important milestone in the construction schedule as we prepare to put the simple cycle unit into operation, scheduled for later this year.
“The gas turbine first-fire is a key point in time during the commissioning process; it marks the first time that the gas turbine is actually operated at the new site. The gas turbines will be the beating heart of this power station, so it always feels like a big step when one of them is started for the first time.”
– Jamie Hodel, project manager of South Hedland’s construction
Systems in check
Starting the gas turbine isn’t as simple as flicking a switch to see if it turns on or not; numerous construction and commissioning verification checks and tests are needed prior to the gas turbine’s first fire. These verifications confirm that the equipment has been installed in accordance with the power station design and is safe to energize for the first time. Our South Hedland power station has many intricate systems that work together to allow the site to operate safely, and each of these systems have vital roles to help control, monitor and power the gas turbines.
“Our EPC contractor has been systematically commissioning and energizing the balance of plant equipment that supplies fuel, water, air and lubrication to the gas turbine. This is a critical process that must be tightly controlled to ensure that we have clear delineation between areas that are still under construction and areas that contain energized equipment.”
One of the more complex systems under commissioning is the gas turbine control system, designed and programmed by IHI Engineering Australia, and is essentially the brain of the of the power station. Testing the system’s communications are working with all power station equipment is critical to ensure that the instrumented functions of the power station are properly and safely working prior to energizing any equipment for the first time.
In addition to testing the systems, it is also important to make sure the fuel, lubrication and cooling systems are flushed clean so that construction debris accumulated during installation does not damage the equipment prior to it going into service. One of the final requirements is for a gas inspector to review the gas system installation and the protection devices and approve the system for operation.
First fire testing
Only once all of these checks and approvals are completed can the gas turbine be started, which successfully marks the first fire milestone. However, this is just the beginning; each and every system has another round of checks and tests to undergo with the gas turbine in operation. This remaining work will take approximately two months.
“It’s great to achieve this milestone but we still have a lot of work ahead of us,” says Jamie. “Before the end of 2016, we still have to commission two more gas turbines, two boilers and prepare the condensate, feed water and steam systems. That will set us up for the final months of steam turbine and air cooled condenser testing and commissioning before we hand the new power station over to the operations team in the first half of 2017.”
With the first fire of South Hedland’s simple cycle gas turbine a success, the team now is in the last stretch of tests and checks before the turbine can be commissioned and begin delivering power later this year.