GE Energy’s Jenbacher gas engine business has made several significant developments in its product and technology portfolio in response to an increasingly diverse array of projects requiring natural gas and specialty gases for distributed energy generation.
GE Jenbacher Gas Engines
Two of the newest advances involve the largest Jenbacher engine type that GE Energy currently offers, the Type 6. With the Type 6 Jenbacher gas engine’s introduction in 1988, GE has continuously developed this engine family, first culminating in the new F-version and, even more recently, the 4 MW,
24-cylinder J624 GS model.
With commercial start-up beginning in 2007, the most important feature of the Type 6 F-version engine is the utilization of the Miller camshaft timing. The Miller effect allows for optimized ignition timing, thus enhancing mechanical efficiency — especially with low methane-number gases. The 1500 r/min model’s key technologies additionally include an enhanced mixture forming and gas control concept to improve dynamic behavior and control accuracy, highly efficient blow-by demisters to prevent oil mist from being returned to the suction side of the turbocharger and flexible bell housing between the gas engine and alternator, thus reducing the transmission of vibrations from the engine to the alternator. There are more than 80 F-version engines in the field, resulting in about 250 000 operating hours of experience.
In June 2007, GE unveiled the J624 GS, representing the first high-speed, 24-cylinder gas engine in the 4 MW power generation segment. The engine, successfully running on the test bench in Jenbach, Austria, fulfiling all output and efficiency expectations, represents a quantum leap in GE’s gas engine technology. GE’s J624 GS lean-burn, turbocharged and mixture-cooled gas engine is the logical next step in the evolution of the Jenbacher Type 6 engine family after the previous introduction of its 20-cylinder models. The J624 GS, with its compact design, delivers the highest electrical output of all existing 1500 r/min high-speed gas engines, according to GE.
Successfully mastered technological challenges of the new engine include designing both engine and turbochargers for an extremely high brake mean effective pressure; controlling the vibrations by decoupling the intercooler and turbochargers, optimizing the combustion sequence; and increasing the mechanical strength of the crankshaft. Scheduled to enter serial production in 2009, the new engine will initially be operated with natural gas at its first pilot installation at a greenhouse in the Netherlands.
In general, both units — the new engine, as well as the Type 6-F version provide the same fuel flexibility and high reliability offered by the entire Jenbacher gas engine portfolio. Additionally, after its commercial start-up in late 2006, GE successfully commissioned several 1800 r/min J420 GS engines for 60 Hz applications in the U.S. in 2007. With a mechanical outputof 1466 kW, these engines are installed for different applications like landfill gas, sewage gas and natural gas in CHP systems.
The engines are equipped withlong-proven features such as the cylinder individual knocking control KLS98, the Jenbacher-developed spark plugs, the TecJetTM gas-dosing valve, offering a high control accuracy degree and also high-efficiency combustion system with Miller LIVC technology.