Modernized drive for ДС-3А for Karmanovskaya GRES

Karmanovskaya GRES is the most powerful condensational heat generating station in Bashkortostan. It is a part of OJSC “Bashkir generating company”. The GRES is situated on the north-west of the region, in the town of Neftekamsk, on the river Buy. It was designed and constructed to use local high-sour oil as fuel there. Now the main fuel used at the station is natural gas.

There are six units at the station; each one consists of steam boiler Пп-950-255ГМ with capacity of 950 ton of steam/ hour and turbo-aggregate K-300-240 with capacity of 300MW. Putting into operation one unit annually the station has become the most efficient in the republic. The electric capacity of the station now is 1800 MW, heat capacity is 204Gkal/h.

Drawing. 1 Karmanovskaya GRES

Under the investment program of development for 2016 at Karmanovskaya GRES it was decided to replace the worn out electric motor of exhauster ДАЗО-1910-12(1700kW, 500rp/m, 6kV).

Specialists of JSC “EnergoFront” got the task to find the optimal variant to replace electric motor ДАЗО-1910-12 for the modern one; moreover, according to the demand of the station the new electric motor must be set on the current basement without replacement of cable.

After the thorough examination of variants in cooperation with specialists from Karmanovskaya GRES it was decided to choose electric motor АДО-1700-6000-12У1 (1700kW, 500rp/m, 6kV with adaptor plate to be set on the current basement of ДАЗО-1910-12) (drawing 2) produced by NPO “Elsib” JSC.

Drawing. 2 Dimension characteristic of electric motor АДО-1700-6000-12У1 produced by NPO “Elsib” JSC

Since 1953 NPO “Elsib” JSC has been known as designer and producer of large high-voltage induction motors for power generating, oil transfer, mining and other industries. More than sixty thousand large electric motors have been produced during the mentioned period.

Electric motors АДО are induction squirrel-cage motors with WWC, used for the drive of exhauster and mill equipment of heat power generating stations. They are exhausters, fans, hammer and ball mills, coal grinders and other mechanisms that have some serious requirements to driven motors:

- reliable start of mechanisms, having high moment of inertia ratio and high resistance moment at decreasing of voltage during start till 0,8 Uн;

- reliable operation at overloads up to 150-200%;

- long-term stable operation at increased vibrations caused with misbalance from mill rotors.

Motors are made with deep-bar rotors and proper contact of bars and iron of claw that allowed decreasing of heating of bars during starts and guaranteed reliable operation of motors with number of starts not less than 5,000 for heavy duties and up to 10, 000 for exhauster equipment for the operation period. These conditions of operation under start duties are proved either with designed data or with real experience of operation at the stations.

Drawing 3. Electric motor АДО-1700-6000-12У1

The suggested electric motor АДО-1700-6000-12У1 (Drawing 3) has some advantages over the current electric motor ДАЗО-1910-12, i.e.:

- electric motor АДО has higher efficiency (efficiency of АДО 95,9 %, ДАЗО – 94%),i.e. high energy efficiency that allow saving of active electric energy and, thus, reduce auxiliary expenses;

- intensified isolation of stator wiring type “Monolit-4” is used on thermo-reactive connectors. It provides increased humid resistance, mechanical (solid heart of stator has increased inflexibility) and electric durability. As a result of implementation of this technology the operation period of electric motor is increased by 50% starting from 30 years;

- electric motor produced by NPO “Elsib” JSC has temperature stator rise- F class;

- weight of electric motor АДО-1700-6000-12У1is less than ДАЗО-1910-12 by 3.5 tons, thus static and electric load on basement will be decreased;

- high protection IP54 of “Elsib” electric motor is more reliable that allows operation under heavy conditions;

- shield design of electric motor АДО, connection of assemblies body-shields-bearing on grind significantly decreases possibility of contacts between rotor and stator;

Examination of the given data proves that electric motor АДО-1700-6000-12У1 is the best solution to replace the worn out motor ДАЗО-1910-12.

Drawing. 4 Current electric motor ДАЗО-1910-12

To provide full correspondence of the designed variant of fixing via adaptor plate to current basement service specialists from JSC “EnergoFront” examined the current basement( drawing 4) at the station and gathered initial data for production of adaptor plate and the electric motor.

After the delivery service specialists from JSC “EnergoFront” will do commissioning and start-up of the electric motor.