G4 at the heart of pipeline compressor station upgrade in Canada
GE's Oil & Gas business recently implemented its new PGT25+G4 power turbine technology in an upgrade project for Alliance Pipeline that will increase power and efficiency while lowering emissions.
Based in Calgary, Alberta, the Alliance Pipeline system transports approximately 1.6 billion cubic feet of rich natural gas from British Columbia and Alberta through Saskatchewan, North Dakota, Minnesota, and Iowa to its terminus in Illinois, USA. There are 14 compressor stations located across the 3,700-km mainline system.
”The debut of our G4 technology builds on our relationship with Alliance, one of the world’s leading pipeline companies,” said Nagel. “GE has provided all of the compression equipment in the Alliance mainline pipeline system.”
The new G4 module replaced an older unit at Alliance’s Windfall Compressor Station in Whitecourt, Alberta. Components were delivered on site in late March and May and, following the G4's successful installation and start-up, the station was returned to service in just three weeks.
Introduced in late 2005, the G4 power module can be applied for both upgrade and new unit projects. It is an upgrade of GE’s well-proven PGT25+ technology and is specifically designed for oil and gas applications including large pipelines and onshore/offshore production facilities.
“Since the package design and the footprint are the same as for the previous PGT25+ unit, upgrading to the more powerful G4 can be done quickly and easily, reducing any downtime,” said Jeff Nagel, Vice President, Global Services for GE Oil & Gas. “This enables our customers to grow without the cost and time involved in replacing an entire plant.”
GE's two-stage, high-speed power turbine module was coupled with an enhanced LM2500+G4 gas generator recently introduced by GE Aeroderivative business. Its 34-MW power output is a 10% increase over the previous model. The unit is also designed to achieve fuel efficiencies greater than 40%, the highest thermal efficiency level in its power range, while also low emissions of 25 ppmvd NOx and CO. The first unit also features control software and hardware customized to meet Alliance’s specific needs.
“We faced several challenges with our first G4 upgrade installation,” said Nagel. “Alliance needed to maintain low emissions while achieving a significant power increase along with high efficiency and availability. The successful start-up has demonstrated that our enhanced technology will meet these requirements.”
Design features include higher firing temperature and axial compressor airflow. Component innovations include a power turbine first-stage blade designed with the new GTD-111 directionally solidified alloy, and a new unit control panel and fuel metering skid designed for more accurate combustion tuning.
The PGT25+G4 comes in both a standard and dry low emissions (DLE) version (for more precise combustion turning as was the case for Alliance in Canada). Operating at a speed of 6,100 RPM, the power turbine is capable of directly driving a compressor without the need of a gearbox in most of oil and gas applications.
"This is a very exciting project," said Alliance's Technical Services Manager David Mucz. "We are the first to use this new technology in this capacity, which keeps our system on the leading edge."
For more information on the G4 upgrade please contact:
Francesca Monti
Francesca.Monti@ge.com
