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ERDEMİR TURBO-GENERATOR/MOTOR BLOWER PROJECT

Savaş YILDIZOĞLU  
Ereğli Iron and Steel Works.Inc.
 
Kdz. Ereğli
 

syildizoglu@erdemir.com.tr

ENERGY CONSUMPTION

PRIMARY ENERGY (PURCHASED) ENERGY  RECOVERED (BY PRODUCTS)
1 440  000 TEP 
(148 million  US$)
580 000 TEP 
(-40%)
 Coal                        %76 Blast Furnace Gas       %60
 Natural Gas             %15 Coke Ove Gas             %34
 Electricity                 %5 BOF Off Gas                 %6
Fuel-Oil                     %4  

ELECTRICITY CONSUMPTION IN 1999  


1.13 billion kWh (1% of National Consumption)
302 million kWh Purchased from Turkish Electrical Authority
396 million kWh Generated in turbo-generators (50 MW)
429 million kWh Generated  in co-generation (77 MW)
%73 generated, %27 purchased

ABSTRACT

Eregli Iron and steel works Inc. (ERDEMIR) is an integrated steel mill where two blast furnaces are in operation. The function of the blast furnace in the steel mill is important and vital. Unplanned shutdown is not permitted. Turbo-blower is the compressor which supplies blast air to blast furnace. In order to supply blast air without interruption a redundant blower is needed.

 Erdemir has by product gases obtained in the processes and the excess gases are consumed as fuel in steam generators. After the cogeneration system is established in Erdemir 100 t/h steam capacity became as excess. Either this capacity should be used or some by product gases should be released.

With TURBO-GENERATOR/MOTOR-BLOWER PROJECT both requirement has been satisfied.

A BRIEF DESCRIPTION OF ERDEMIR

The total crude steel production of Turkey in 1999 is 14,3 million tonnes, ranking as the 17 th. Largest steel producer in Europe.

Ereğli Iron and Steel Works Inc. (ERDEMİR) is the largest steel producer of Turkey and the only integrated steel plant producing flat steel products. Erdemir’s share of the total crude steel production in Turkey for 1999 was 18 percent.

Erdemir began operation in 1965 and now has a crude steel capacity of 3 million tons per year. It is located on the Black Sea coast at the town of Kdz.Ereğli, 270 km away from İstanbul.

Erdemir meets about 40-50 % of domestic flat steel requirement and exports 20 –25 % of its sales, mainly to European Union, USA and Japan.

The integrated steel plant of Erdemir occupy a site of 4 square kilometers and include harbour facilities, coal and iron ore stockyards, coke plant, sinter plant, power house, dam and water systems. The iron and steel making facilities include two blast furnaces, basic oxygen furnaces, hot and cold rolling mills.

Erdemir’s main strategy is to be a global company by modernizing the existing facilities with latest technologies and installing new hi-tech facilities. Erdemir was awarded ISO 9002 quality systems certificate in 1997. ISO 14 001 environment certificate is under study and probably will be awarded by the end of this year.

The quality and the price are main factors in the market. The market itself determines the price. To make a profit the only parameter which can be controlled is the cost. In flat steel production at ERDEMİR the cost distribution is,

Cost Distribution   ( % )

Consumable 10
Labour 21
Energy 27
Raw material 20
Other 22

 

The only parameter which can be controlled and reduced is the energy consumption.

In 1982 energy consumption per ton crude steel was 8220 Mcal.

After the application of many energy saving projects and modernization, energy consumption per ton crude steel was 5160 Mcal in 1999.

Energy saving percentage is 37 % .

In order to decrease the energy cost the more by products have to be consumed as fuel in the processes .  

In 1997 co-generation, consisting of;

2x38,5 MW Natural Gas Turbo Generators,

2x80 t/h Waste Heat Boilers, were taken into operation .

Steam generators which consume by product gases had 100 t/h excess capacity because of the waste heat boilers.

STATEMENT I

  A 25 MW TURBO-GENERATOR IS NECESSARY TO MAKE USE OF STEAM CAPACITY.

ERDEMİR has two Blast Furnaces which produce 7000 tons/day hot metal.

There are three turbo blowers to supply blast air to two Blast Furnaces. Two Blowers are in operation in one to one correspondence and the third one is a stand by as a cold spare . If one of the operating turbo blowers fails by some reason, the related blast furnace has to shut down and a certain amount of damage might occur. The cold spare third turbo blower can be started up nearly in two hours. The hot metal production decrease and some damage in the Blast Furnace is unavoidable.

In order to prevent such a situation

STATEMENT II  

TWO BLAST FURNACES NEED A STAND -BY MOTOR DRIVEN BLOWER AS A SPARE

THE STUDY FOR;

STATEMENT I
25 MW turbo-generator is necessary to make use of that steam capacity.

STATEMENT II

Two Blast Furnaces need a stand-by motor driven blower as o hot spare.

Came to a conclusion as
Turbo-Generator/Motor-Blower Project.

2- TURBO GENERATOR / MOTOR BLOWER PROJECT

In order to have economical and efficient operation in industry turbine-generator and turbine-blower are combined together recently. Instead of having a cold spare blower (blast air copressor) which can be put into operation in two hours, it is preferred to have a running steam driven turbo-generator which is capable of driving a blower as soon as it is needed. This combination is desingned for blast furnace use.

Steam turbine drives the generator to generate electricity and during the operation it is possible to decrease the generator load and drive the blower in 90 seconds to give service to the blast furnace of which turbo-blower has tripped by some reason.

Turbo Generator/ Motor Blower System

As shown Figure 1 consist of;

Steam Turbine (as driver )

Motor-Generator (When steam is available functions as generator to generate electricity and when steam is not available functions as Electric Motor to drive the blower)

Voith geared turbo coupling ( Between Motor/Generator and blower)

Blower (As driven by steam turbine)

OPERATION MODES

MODE 1) STEAM TURBINE – GENERATOR OPERATION (Figure 2) Steam turbine drives only generator for generating electricity (maximum load 25 MW)

VOITH GEARED TURBO COUPLING UNCOUPLED

MODE 2) STEAM TURBINE – GENERATOR – BLOWER OPERATION (Figure 3)

The main purpose of installing this plant is to provide blast air to BF 1 and BF 2 in case its existing turbo blower fails to supply blast air due to any reason except planned trip. Normally the plant will run in MODE 1. During MODE 1 operation if one of the turbo blowers trips, this machine will automatically engage the Voith geared turbo coupling to drive the blower and supply air totally in 90 seconds. The plant will supply blast air with minimum required capacity of related blast furnace.

MODE 3) MOTOR-BLOWER OPERATION (Figure.4)

When this plant is stand by (cold spare) and one of the operating two turbo blowers fails to supply blast air, the motor will start. When the motor has reached its nominal speed the Voith gear will be activated and the blower will be coupled. In 90 seconds the blower will provide blast air to blast furnace.

MODE 4) STEAM TURBINE – BLOWER OPERATION (Figure 5)

Steam turbine drives the generator rotor, generator rotor only serves as a mechanical clutch and drives the blower through Voith geared turbo coupling.

All of the operations can be performed either on automatic or on manual control.

CONCLUSION

By this project Erdemir will have many advantages.

200 million kWh additional electricity will be generated annually

-The price of purchased electricity is about 6 cents/kWh

-The cost of generated electricity is about 4 cents/kWh

(The cost of energy will be less)

All the by product gases will be consumed in the steam generators. (The cost of energy will be less)

Erdemir will generate 85% of the electricity needed.

Redundancy of the blast air of blast furnaces will be provided.    

syildizoglu@erdemir.com.tr


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