AES Meghnaghat Combined Cycle Power Plant

Owner: AES Meghnaghat Limited

• Electrical Power 450 MW
• 2 Ansaldo V94.2 Gas Turbines with air-cooled generators 135 MW each
• 2 Hyundai triple pressure HRSGs with duct firing
• 1 Fuji triple pressure steam turbine with air-cooled generator 180 MW

Background

The Meghnaghat 450 MW Gas-Fired Combined Cycle Power Plant is located on the northern bank of the Meghna River just off the Dhaka-Comilla highway in the District of Narayanganj, Bangladesh approximately 22 km Southeast of Dhaka.

Process Technology

The plant is a 2+2+1 configuration, (two gas turbines, two HRSG’s and one steam turbine) and is a multi shaft design for gas turbine and steam turbine generators.

The exhaust from each of the two 2 Ansaldo V94.2 gas turbines with air cooled generators is directed into Hyundai Heavy Industry triple pressure, natural circulation, Heat Recovery Steam Generators with supplementary firing, producing superheated HP-steam, superheated reheat steam, and superheated LP-steam. The steam from the two HRSGs drives a Fuji double casing, triple pressure reheat, condensing Steam Turbine and its air-cooled generator..

The plant is designed to have a guaranteed net output , with duct firing, of 450 MW at the the high voltage side of the 230 kV transformer corrected to the reference conditions.

The gas turbine gross electrical output is 137.4 MW, and the steam turbine gross electrical output is 189.8 MW measured at the generator terminals after deducting excitation power losses of the generator.

The essential plant operation and management functions of start-up, shut down and normal load operation are done with the operator maxSTATIONs of the Plant Automation System (PAS). The PAS is integrated with the gas turbine control system, steam turbine control system and with auxiliary control systems for remote control and supervision.



Metso’s Scope of Supply

The Metso Plant Automation System (PAS) monitors, controls, and optimizes the performance of each unit and the common services at the plant site. The PAS provides the following functions:

• Automatic plant start-up and shut-down control (APS)
• Automatic power regulation control (APR)
• Modulating control
• Data acquisition
• Sequence of events reporting 1 millisecond resolution
• Electrical switch-gear control.
• Redundant maxLINKS – to interface with gas and | steam turbines, gas compressor system, gas metering station, water and waste water treatment system, duct burner system
• Billing package – To provide automated billing
• maxCALCS - performance calculation package

The functions of HRSG controlled by the PAS include:

Modulating control

• High pressure drum level control
• Intermediate pressure drum level control
• Low pressure drum level control
• High pressure super-heater steam temperature control
• Re-heater steam temperature control

Binary control

The Automatic Plant Start-up / Shut-down control application (APS) within maxDNA controls the start up and shut down of the gas turbines, HRSGs, and steam turbine. maxDNA is completely integrated with plant floor sub-system controls and their packaged auxiliary systems through redundant maxLINKS processors.

The PAS contains over 9,000 measured process variables and a similar number of calculated variables. From the control room, operators can routinely monitor and control each unit and the supporting common equipment. The PAS includes the following elements

• 6 Operator maxSTATIONs
• 1 Engineer’s maxSTATIONs
• 2 maxLINKS interfaces
• 1 maxSTORIAN
• 10 Pairs of Distributed Processing Units (DPU4E)
• 5 Operations alarm, log, and screen printers