• General information and main characteristics of GE LM6000 turbine
• GE LM6000 turbine design
• Turbine cycle

The General Electric LM6000 is a twin-shaft gas turbine based on the CF6-80C2 aircraft engine (also manufactured by General Electric). This turbojet engine was first put into service in 1985 and is still widely used today in wide-body airliners. GE used successful operating experience of more than 30 million flight hours with 99.88% reliability to create the LM6000.Both engines have a similar design. The low-pressure turbine, high-pressure compressor, high-pressure turbine and combustion chamber are virtually identical. Proven elements manufactured in high volume contribute to the low initial cost and high operating efficiency of the GE LM6000.

The additions and modifications were designed to make the unit more suitable for ship propulsion, power generation and offshore power generation applications. Differences between the engine and turbine include an enlarged turbine section to convert thrust to power at the shaft, supports and struts for mounting on steel or concrete decks, and modernized controls for power generation. Taking advantage of the CF6-80C2 engine’s 3,600 rpm speed, the LM6000PC applies the load directly to the low-pressure turbine shaft. The LM6000PG operates at 3900 rpm, but the big plus is the additional power for the same unit size. Both models utilize inexpensive, field-proven parts.

The turbine is a unique two-speed low and high pressure system. The purpose of the plant is energy production (electricity, heat and power).

The electrical efficiency is 41% (simple cycle). Specific fuel consumption is about 200 g/kWh. The weight of GE LM6000 is approximately 8 tons, which is almost half the weight of other large turbines based on aircraft engines. The LM6000 turbines are available in 50 Hz or 60 Hz versions. Installation dimensions (PC/PG): length 4.91 m, width 2.159 m. Available in models: LM6000PC, LM6000PG; LM6000PF.

LM6000PC	LM6000PG	LM6000PF

Applications

More than 1,100 General Electric LM6000 units have already been delivered or are in operation in the industrial sector, as a drive for electrical generators for power generation and as a mechanical drive for liquefied natural gas (LNG) compressor units. Examples of GE LM6000 turbine applications include: warships; floating oil production, storage and offloading systems; LNG tankers; hospitals; airports; pulp and paper, cement, and mining plants.

Environmental aspect

The GE LM6000 is the first aircraft engine-based gas turbine to expand fuel choices beyond traditional fossil fuels and now has a proven ability to operate on one of the cleanest forms of biofuel, ethanol from Brazilian sugarcane.

The ethanol initiative stems from GE Energy and Petrobras’ shared interest in demonstrating the capabilities and benefits of this biofuel. While running on ethanol from Brazilian sugarcane instead of No. 2 diesel, the LM6000-PC can generate equivalent power while reducing NOx, C02, S02 emissions and reducing water used to dilute emissions. Environmental benefits over 4,000 hours of operation include:

1. Reduction of carbon dioxide (C02) emissions by approximately 6% or 6,500 metric tons. This is equivalent to the annual C02 emissions of over 1,800 cars on Brazilian road.
2. Reducing water consumption (used as a diluent in the combustion process) by approximately 20 million liters. This is equivalent to the amount of water used by 72,000 people in São Paulo in a day.
3. Reduction of sulfur dioxide (S02) emissions by approximately 73 tons.
4. Reduction of nitrous oxide (N02) emissions by 3% or 3.3 tons.

Benefits

An efficient, flexible solution for changing industrial needs.

• Fast start-up with acceleration to full power in less than five minutes – even in part-load mode.
• Designed for cost-effective duty cycles.
• Modular configuration, lightweight for easy transportation, installation and on-site maintenance.
• Optimized performance on hot days with a SPRINT® system that injects fine spray water to cool the air in the compressor.
• Robust design with the industry’s highest reliability (> 99.8%) and component availability (> 98.4%).
• Proven simple and combined duty cycles.
• Each turbine is fully tested at the factory prior to delivery.

GE LM6000 PC/PG Turbines:

• Reaches maximum power in less than 10 minutes, start-up takes no more than 5 minutes.
• Emissions level of 25 parts per million.
• Proven SAC system provides the ability to burn a variety of fuels (kerosene, propane, coke oven gas, ethanol and LNG) using water injection to reduce exhaust emissions.

GE LM6000 PF/PF+ turbines:

• Combined cycle with over 56% efficiency.
• Power ramping capability of 50 MW/min.
• DLE technology with 15 ppm emissions.

GE LM6000 turbine design

The GE LM6000 turbine consists of four sections: low pressure equipment (outer sections) – five-stage turbine, five-stage compressor; high pressure equipment (located between the outer sections) – two-stage turbine, fourteen-stage compressor. The turbine also includes a combustion chamber; radial inlet; 30 fuel injectors and double igniters; boroscopic ports for diagnostic examination; drive unit for the starting system, oil and suction pumps; connecting elements and protective devices.

The modular design of the LM6000 turbine was developed by General Electric specialists to ensure maximum maintainability and minimum downtime for maintenance operations and parts replacement.

Some versions of the General Electric LM6000 are equipped with a Dry Low Emission (DLE) system designed to suppress emissions dry.

GE LM6000 turbine engine types:

• SAC (Single Annular Combustor), стандартная версия (LM6000PA, LM6000PC, LM6000PG);
• DLE (LM6000PB, LM6000PD, LM6000PF, LM6000PH).

Main components of GE LM6000 turbine

• Main gearbox
  Gear ratio 1.209:1.
• Electrical generator
  Brushless excitation system; air-cooled; stator winding with class F insulation.
• Power unit enclosure
  Designed to protect against precipitation and absorb noise (up to 85 dB on average).
• Air intake system
  High efficiency integrated air cleaning unit (IACU) of multistage design; noise absorption system; support structure, ladders and platforms.
• Exhaust system
  Axial exhaust, connecting flange..
• Mesh screen
  Protects the turbine from foreign bodies. The material of the screen is stainless steel.
• Support frame
  The structure of the support frame has high rigidity and strength.
• Fuel system
  Natural gas; water injection for NOx, liquid/liquid and gaseous fuels.
• Synthetic and mineral lubricating oil systems.
• Hydraulic starting system
  Includes 151 liter reservoir, electrically driven hydraulic pump, cooler, filters, hydraulic motor, and control system.
• Piping connections
• Fire Protection System (FPS)
  The FFS includes sensors, nozzles, piping, a carbon dioxide cylinder module, and devices for powering the FFS.
• Plant Control System
  Common equipment: fuel control system, voltage regulator, controller (Woodward Micronet Plus), critical monitoring system, meters, gauges, measuring instruments, generator relay protection, automatic excitation control, human-machine interface.
• Compressor cleaning system
  Compressor flow part flushing system in operating and non-operating mode.

Turbine cycle

1. Inlet guide apparatus
2. Drive flange
3. Five-stage low-pressure compressor
4. Bypass air collector
5. Fourteen-stage high-pressure compressor
6. Combustion chamber
7. Two-stage high-pressure turbine
8. Five-stage low-pressure turbine
9. Piping for fuel supply to injectors
10. Auxiliary gearbox

The turbine cycle includes the following steps:

• Filtered air enters the intake cone and passes through the guide vanes to the low-pressure compressor (LPC)
• The LPC compresses the air at a ratio of 2.4:1
• Air exits the LPC through the front frame and bypass air collector to the high pressure compressor (HPCC)
• Air enters the HPC through the inlet guide apparatus
• The HPC compresses the air at a 12:1 ratio
• 30 (SAC) or 75 (DLE) fuel injectors mix the air and fuel
• The air-fuel mixture is ignited in an annular combustion chamber
• The hot gaseous combustion gases expand in the high-pressure turbine (HPT), driving the AHV
• The hot gaseous combustion products then expand in the low pressure turbine (LPT), driving the LPC and load
• The flanged end of the LPC shaft drives the generator with the electrical load
• The exhaust gases exit the engine/system through the exhaust flange

CEM GmbH offers the supply of all necessary new or remanufactured spare parts, OEM parts as well  as service and repair services for GE LM6000 turbines.