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Alpiq in: Hungary
Alpiq Group

Electricity generation at Csepel II

The Csepel II Plant is a combined-cycle gas turbine (CCGT) power station of 403 MW electrical capacity with the option to supply district heat. The power station has two gas turbines which are connected to two heat recovery steam generators (HRSG) to provide steam for the steam turbine. In addition to the main plant items, the site also has a Water Treatment Plant, four hot water boilers and one auxiliary steam boiler to supply district heat, plus distillate unloading, transfer and storage facilities, and a gas reduction, filter and receiving station.

Power station main fuel is natural gas, and distillate may also be burned as a backup fuel.

The Plant provides nearly 7% of the annual demand of Hungary. It is connected to the national grid at 120 kV voltage level.

Gas turbines
Each of the two single-shaft GE MS9001E gas turbines consists of a 17-stage compressor, a burner equipment with 14 ring burners of low NOx-emission and a 3-stage power turbine. Gas turbines are within noise suppression enclosures. Each gas turbine has an electrical capacity of 142,5 MW at 1 °C ambient temperature and 1013 mbar pressure. Maximum output capacity can be reached with both natural gas or distillate fuel.
A generator connects onto the hot end of the turbine. Turbine exhausts flow into the connected heat recovery steam generators through 5 m diverter dampers.

Heat recovery steam generator
The heat recovery steam generators, made by AE Energietechnik, run with the exhausts of gas turbines. Exhausts may also avoid the heat recovery steam generators and enter directly the stacks through diverter dampers.
The water side of heat recovery steam generators consists of a district heating circuit, and a high-pressure and a low-pressure part. For better heat transfer,  water flows in horizontal finned tubes. Boilers have natural circulation. Boilers are supplied with water by two feed pumps from the low-pressure drum to the high-pressure drum. Both the low-pressure and the high-pressure sections have a feed water preheater, evaporator equipped with boiler header and a superheater. The low-pressure boiler drum also contains a de-aerator head. Low-pressure section and high-pressure section operating parameters are 184 °C, 7.2 bar and 512 °C, 89 bar respectively.

Steam turbine
The steam turbine is a single-shaft axial designed GE MS9001E with low-pressure and high-pressure sections. The high-pressure section has 14 stages, and the low-pressure section has 5 stages. The generator connects onto the steam turbine by rigid coupling.
The steam turbine may run in full condensation or partial extraction modes when heat is extracted for the district heating system. In full condensation, steam turbine capacity is 118 MW.

Condenser with water cooling
The condenser of the steam turbine is from ABB, cooled with river water, with a rigidly supported, one-way design. The condenser has 1950 non-corrosive steel tubes on the surface of which steam from the steam turbine condensates and transfers heat to cooling water extracted from the Danube. To improve efficiency of heat transfer, a Taprogge system with sponge balls is connected to it.

District heating system
A 3-stage district heating heat exchanger system was built for heat supply to the township. In the return line of the district heating circuit water is first preheated in the heat recovery steam generator and then it flows through the heat exchangers of the district heating circuit. Heat energy for heating purposes is obtained primarily from the steam turbine but the heat recovery steam generators may also provide heat directly through the pressure reducers, and the four hot water boilers can also produce heat.

Generators and transformers
Csepel II Plant has three identical ELIN generators connected to the two gas turbines and the steam turbine. The generators' capacity is 164 MVA at 15.75 kV output voltage. The generators have air cooling underneath, and the air cooling system is cooled by the closed-circuit cooling water system. Generators are connected to the main transformers by ABB circuit breakers filled with SF6 gas.
Generators are connected to the main transformers, their capacity is 160 MVA, which raise voltage to 120 kV. Transformers are ELIN-made with automatic tap changers, cooled by heat exchangers with air fans.

Auxiliary plant
Electrical auxiliary feed comes through three 6 kV distributors. Two of the distributors feed the two gas turbines, and one general distributor is fed from the distributors of the two gas turbines. Each gas turbine distributor has a 1600 kVA transformer which feed the 400 v distributors no. 1 and no. 2. Two 1600 kVA transformers are connected to the 6 kV general distributor feeding the 400 V general distributors no. 3 and no. 4.

Emergency backup
The backup to the 400 V main distributors is the emergency diesel distributor fed by two 500 kVA Cummins diesel power generators. That capacity is sufficient to safely shut plant down in case of a grid blackout.

Electricity generation
Alpiq Csepel generates power in Csepel II Power Station, which has a built-in capacity of 403 MW. This power station is the most efficient among the large CCGT power stations in Hungary. It started commercial operation on November 1, 2000, and has been one of the most reliable and flexible producers in the Hungarian power system.
During the commercial operation, the technical condition and our internal processes have been monitored, and a number of steps have been made in order to improve the reliability and efficiency of our power stations and to better our processes. A capacity monitoring system was installed on site, an air chiller system was built into the power station, and gas turbine blades were replaced with higher efficiency blades. Our organisational structure has been re-shaped for a better efficiency in recent years.
Our power generation focuses on the demand of customers. Thanks to the flexibility of the power station, diverse requirements can be met. In order to satisfy the regulation and reserve power demand of domestic electricity system, we are providing secondary, minute and hour regulation. We offer our clients flexibility and the diverse product range of an outstanding reliable power station.