Reconstruction of energy unit №2 at Iriklinskaya GRES

Iriklinskaya GRES (IGRES) is one of the biggest heat stations at the South Urals. It’s situated in Energetik (Novoorsky district, Orenburg region) on the bank of Iriklinsky dam pond on the river Ural. Its activity is to produce electric energy and distribute it to whole- sale market and supply heat to Energetik.

The TPP consists of 24 branches including 8 energy units with capacity of 300 MW each and hydro power station 30 MW. There are turbines produced by Leningrad metal works K-300-240 and boilers ПК-41(energy units №1,2), TГМП-114( units № 3,4), TГМП-314( units №5-8).

Installed electric capacity of IGRES is 2.430 MW ( including 30MW of hydro power station), and installed heat capacity is 121 Gkal /h( including 1Gkal/h of the boiler of hydro power station). Natural gas is the main fuel used at the station and oil slurry is auxiliary. The produced power is distributed via high voltage lines 500, 220, and 110 kV. The stations feeding such large industrial companies as Orenburg gas-transfer plant and Magnitogorsk metal combine are connected with these lines.

Reconstruction of energy unit №2.

In the third quarter of 2015 the large reconstruction of the second energy unit began. Modernization of the unit will increase efficiency of work, prolong the term of operation for 30 years, increase energy efficiency of the unit up to 40,5 % and capacity of the unit from 300 MW to 330 MW. A year-round economical effect from modernization of the unit will be increased due to increase of the payment for capacity, increase of efficiency of equipment, participation at the market of system services and reduction of repair costs. In 2014 the modernization of OSG-110kV was started with replacement of circulation water pipes of unit №6 , the reconstruction of oil facilities is in progress now, etc. The modernization of the main and auxiliary equipment of energy unit №2 will be completed till summer 2016.

Under this modernization JSC “Power machines” will supply the equipment for more than 1 billion rubles, namely: low pressure rotor and flow part of low pressure cylinder of turbine K-300-240 by LMW and other equipment.

JSC “EnergoFront” will take active part in this reconstruction. In particular till the beginning of 2016 the supply of the following equipment to replace the worn-out one will be completed:

-modernized booster pumps ПД650-160-2 with electric motors 4АЗМ-500/6000-УХЛ4- 3 pcs.

-electric motor 4АЗМ-8000/6000-УХЛ4( 8000kW,3000rp/m,6kV)-1pc as the drive for feeding reserve pump СВПЭ-320-550.

- double speed electric motor 2АДО-С-800/500-6000-8/10У1 (800/500kW, 750/600rp/m)- 1pc as the drive for fan ВДН-24х2II.

Modernized booster pumpsПД650-160-2.

Special attention JSC “EnergoFront” paid to the project of supply of modernized booster pumps ПД650-160-2 with electric motors 4АЗМ-500/6000-УХЛ4.

Reliable non-stop operation of energy units of heat power stations is mainly determined with the quality of their pump equipment and firstly feeding group. As the main feeding pumps of energy units with capacity 300 MW feeding turbo pumps are used. They are high-head and high-rotation multi-stage pumps of high capacity to transfer hot water.

To provide required positive suction head for high-rotation pumps and thus to avoid cavitating in impeller of the first stage the compulsive setting of booster pumps is necessary. At usage of turbine drive for feeding pump booster pump is taken as a compound part of multi component pump.

Now old design booster pumps ПД-650-160 and 12ПД-8 are in operation at Iriklinskaya GRES. Each energy unit has 3 booster pumps ( 2- for operation , 1-reserve).

Booster pumps ПД 650-160, which case parts are made from steel 20L acc. to GOST 977 80 have been produced commercial since 1980. Till that time pumps 12ПД8 had been supplied in cast iron design.

During the operation period of pumps it was found out that while the period 1,5…3 years there has been washout of surfaces of horizontal connection end and case between head and suction sections, places of O-rings of impellers. There also were some claims about operation of bearing assemblies. To increase reliability of operation and prolongation of inter-repair time up to 12 years, booster pump was significally redesigned and the new pump got the new name ПД 650-160-2.

Drawing.1 Sectional drawing of pump ПД 650-160-2

During the modernization of pumps ПД 650-160-2 the following tasks were completed:

- full interchangeability of modernized pump both in characteristics and dimensions with the pumps set at the stations (ПД 650-160 and 12ПД-8);

- to avoid flow of liquid from high-pressure chamber to low pressure chamber and washouts of case parts connected with it, case of pump is made from solid cast( without horizontal connector);

- the flow part of pump was modernized, efficiency of pump at nominal duty is 86%, that is more than the same value of efficiency of pump ПД 650-160 by8%;

- vibration speed of bearing chambers was decreased: at nominal input 650 m3/h it is 2,7 mm/s, at min. input 130m3/h-4,0 mm/s and at max. input 1100 m3/h-3,2 mm/sснижена;

- as the material of the case high-chromium steel austenite-to- martensite class 06Х12Н3ДЛ acc.to ТУ 108 978 80 or CA6NM acc.to ASTM А487М 93. Their resistance against erosion washout is 8-10 times more than the one of steel 20Л;

- for easy welding to pipes from carbon steel, adaptors from carbon steel are welded on pump tube assembly;

- to decrease vibration of rotor, impellers are made from two parts with shift of blades at the outlet of pumped medium from impellers;

- gland seals of shaft were replaced for mechanical end seal ;

-flexible plate coupling to connect shafts of motor and pump was used;

- design of bearing chambers was modernized.

To provide possible dismantling of end seal without replacement the driven motor from its basement, shaft of motor is shifted related to shaft of pump on 150 mm.

Drawing .2 Modernized ПД 650-160-2 in operation

Long-term experience (more than 10 years) of usage of booster pumps ПТА 3800-20-1 at units of NPS with reactors VVER 1000, and ПД 1600-180-2 at units 800 MW of heat power stations proves reliability of the new pump. Audit of these pumps are made not oftener than one time in four years where only seal rubber rings and plate washings are changed. Acc. to information from the sites of operation there haven’t been any capital repair of these pumps till now.

So at Iriklinskaya GRES for modernization of unit №2 the full replacement of pumps ПД 650-160 and 12 ПД8 for more effective pumps ПД 650-160-2 will be completed.

Commissioning and start-up

After the supply according the contract specialists of service department of JSC “EnergoFront” will make commissioning and start-up of the following equipment:

- pump units ПД650-160-2 with electric motor 4АЗМ-500/6000-УХЛ4-3 pcs.,

- electric motor 4АЗМ-8000/6000-УХЛ4 – 1pc.

- double speed electric motor 2АДО-С-800/500-6000-8/10У1- 1pc.

The beginning of commissioning is planned for the first quarter of 2016.