Alstom turbine upgrade

Alstom is introducing an upgraded version of its GT13E2. The GT13E2 E-class turbine was originally launched in 1993. More than 150 have been installed worldwide representing a total generation capacity of over 32 GW. The new GT13E2 turbine has over 202.7 MW of power, 10% more electricity compared to the earlier rating. The higher output is offered at an increased efficiency of 38% (0.2% higher than before).

Every major area of the engine’s performance has been enhanced. The compressor design is taken from Alstom’s industrial-class GT24 gas turbine, a development that allows it to deliver the additional output. The engine also lowers carbon dioxide emissions and cuts water consumption by as much as 60% when burning oil (it runs on natural gas or diesel oil).

“The major changes are in the compressor and combustor,” said Michael Ladwig, Director, Marketing & Product Management, Gas Turbines at Alstom.

The compressor utilizes the low pressure (LP) compressor of the Alstom GT24 turbine. This compressor has enabled the company to increase the mass flow of the engine by 10% and thus boost power by a similar margin.

On the combustor side, Alstom has modified the EV burner improved to what is now called the AEV Advanced Environmental (AEV) burner. Ladwig said the AEV had been successfully validated at three customer sites. They report improved emissions at lower loads and at a range of different temperatures.

“The AEV customer has four air slots instead of two before in the EV burner so it can handle more air,” said Ladwig. “That allowed us to reduce the number of burners from 72 to 48. The result is a simplification of the combustion chamber which in turn reduces maintenance requirements.”

Variable Guide Vanes (VGVs) were also modified. While the GT24 had 3 VGVs, the GT13E2 only had one. This latest upgrade increases the GT13E2’s VGV numbers to that of the GT24. That helps the turbine to better control mass flow into the compressor so it can accommodate lower loads more efficiently.

“Normally, lower load means lower efficiency,” said Ladwig. “This compressor minimizes the loss of efficiency so operators can turn it down.”

At 75% load, these upgrades make engine efficiency 1% better. At 50% load, a four- to five-percent increase in efficiency is realized. Emissions-wise, NOx on fuel gas will be 15 ppm at full load and 25 ppm at 50% load.

In addition, the machine has two modes — high performance and low maintenance. If the GT13E2 is run at 95% load, i.e., maintenance mode, the time between inspections is lengthened by 50%.

“Most users prefer the maintenance optimized mode,” said Ladwig.

He also called attention to startup times — 15 minutes to provide 200 MW. This comes without a lifetime penalty if the turbine was shutdown 60 hours ago or more. That makes it a good target for peaking markets, he said.

A combined cycle version, the KA13E2-2, is also being prepared for market. This will have a two-on-one configuration — two gas turbines and one steam turbine. Its output will be 565 MW and it will run at 53.8% net plant efficiency.

Siemens’ China compressors

Siemens Energy will supply China, together with its Chinese joint venture, Siemens Industrial Turbomachinery Huludao Co. (SITHCO), the first two large-sized, pre-engineered, integrally geared compressors for an air separation plant. Purchaser is Hangzhou Hangyang Co. The new air separation unit will supply gas for a nonferrous metal smelting plant in the city of Fangchenggang in the Guangxi Zhuang region in Southern China.

The plant will go online in 2013. The Siemens scope of supply encompasses two STC-GC compressors, each with three stages, including geartype coupling, lube oil unit, inlet expansion joint and other auxiliary systems. The inlet volume flow of the pre-engineered compressors is about 200,000 m³ air per hour. In the air separation process compressor efficiency is of utmost importance.

The extension of the STC-GC compressor series covers the 120,000- 400,000 m3/h capacities at a pressure ratio of 6.5 with three impeller stages and adjustable inlet guide vanes for compressor control.

CNC endworking

The flexible endworking of tubes and pipes is crucial for the production process in the automotive, petrochemical, ship and offshore industries. Arla Maschinentechnik GmbH, Wipperfuerth, Germany, has built Computerized Numerical Control (CNC) endworking machines, which are available for single-sided and double- sided machining. This machine works like two separate CNC lathes operating independently for every side. The principal difference is that the endworking concept comprises a fixed workpiece and revolving tools.

Coolant and lube filter

Eclipse Magnetics has launched the Micromag HP50 magnetic filter for applications up to 50 bar fluid pressure. It is designed to eliminate common coolant and lubricant circulation problems on machine tools and wash systems. Ferrous particles produced during machining processes, such as grinding, milling and drilling, are a major cause of poor surface finish, drill burning, filter blockages and tool breakages. The HP50 features a high-intensity magnetic core which extracts ferrous particles down to sub-micron size.

GT filter in harsh conditions

The GE TS1000 coalescer is a gas turbine filtration product aimed at power generation facilities in harsh conditions near coastal environments. Coalescers remove moisture in the air stream, which protects the downstream filters and the turbine. This is essential in environments with high levels of ambient moisture — humidity, rain, fog and mist. Coalescers also can help remove liquid-phase corrosives, reducing the likelihood of reaching the turbine and causing damage.

Radial seal rings

Metallized Carbon Corp. (Metcar) announced the availability of custom radial seal ring assemblies, also known as packing rings. They are used to prevent leakage of industrial blowers, pumps and other turbo machinery by sealing the clearance between a rotating or reciprocating shaft and the stationary housing. The carbon-graphite seal rings are manufactured by Metcar. More than 150 grades of proprietary carbon-graphite material are available, depending upon the environment, shaft, housing materials, or rotational speed.

Redundant turbine control

Turbine Technology Services Corporation (TTS) has designed triple modular redundancy (TMR) for gas turbine control applications. It leverages the Rockwell Automation Trusted TMR controller to provide enhanced safety and availability for power generation and gas compression applications. The controller incorporates a fault-tolerant architecture to help eliminate spurious system trips. It also provides high availability as part of its inherent safety-related functionality.