The idea of using jet engines to produce electricity has been around for a while. The word “aeroderivative” is a nod to the machine’s heritage, meaning that the designers borrowed technology originally developed by their aerospace colleagues at GE Aviation.
The technology is also a good example of what GE calls the GE Store — the system of sharing technology, research and expertise among its many businesses. Today, aeroderivatives power towns and factories but also oil platforms and ships.
Engineers built the first generation of GE aeroderivatives called LM100 from a helicopter engine in the late 1950s. The next machine, the LM1500, had inside components from GE’s first supersonic engine — the J79 — and generated more than 10,000 kilowatts. GE Power kept improving on the design, building aeroderivatives from the CF6 engine, which powers Air Force One and many other Boeing 747s, as well the F404 engine used by F/A-18 Hornet and F-117 Nighthawk military jets. Aeroderivatives based on these engines generate electricity in remote corners of the world and also power the world’s fastest passenger ferry.
But the LM9000 takes the technology to a new level. GE’s Oil & Gas business developed the machine for powering massive liquefied natural gas (LNG) plants. “An LNG plant is like a giant refrigerator, but instead of making ice and keeping your food cool, it turns natural gas into liquid by bringing the temperature down to minus 160 degrees Celsius,” says Tayo Montgomery, customer applications engineer at GE Oil & Gas. He says the LM9000 is so powerful it enables LNG plant operators to restart production without first draining the refrigerant from the entire plant. “It has enough power and starting torque than you can just get up and go.”
The GE90 engines have clocked 41 million flight hours since they first entered service in the mid-1990s and have departure reliability of 99.98 percent, according to GE. They are also very light and relatively easy to maintain. “It can take as long as 24 days to do a major maintenance of gas turbines typically installed in older LNG plants,” Montgomery says. “But we can replace the entire LM9000 turbine in 24 hours.”
The team made other adaptations to optimize the LM9000 for industrial applications. They switched the machine’s combustion system from jet fuel to natural gas. The machine also will have a 3D-printed combustor whose innovative design will enable the machine to meet low-emission requirements around the world.
Under the hood, engineering geeks will search in vain for a gear box. That’s because the design utilizes “free power” turbine architecture that enables the machine to operate efficiently over a wide range of power and speed conditions.
As a result, “the LM9000 will provide the highest availability with the lowest cost of ownership for LNG applications,” says Preetham Balasubramanyam, the product manager for the new machine at GE Oil & Gas. He say the LM9000 generates 20 percent more power, can go 50 percent longer without service and emits 40 percent less NOx emissions than existing models in the class. He says that the combination could help LNG plants lower production costs by 20 percent.
The first turbine is slated to enter service in the first half of 2019.