Eraring Power Station – NSW, Australia

Vertical Condensate Extraction Pump Upgrade

Written by: Greg James, Hydro Australia
Publisher: Pumps & Systems / October 2014

 

 

Station History
Eraring Power Station, located in the coal belt area at Lake Macquarie on the central coast of New South Wales, began generating in 1982, with all four units commissioned between 1982 and 1984. Formerly state owned under the banner of Eraring Energy until mid 2013, the station is now owned by Origin Energy, one of Australia’s largest electricity generators and retailers.

The power station underwent a significant upgrade during 2010 to 2012, increasing the output of all four generating units from 660MW to 720MW each. Eraring is the largest generating unit in the Origin group and has established itself as Australia’s largest power station since the upgrade.

Condensate Extraction Pumps
The pumps are the standard arrangement of condensate extraction pump used in the power generation industry: underfloor, vertically mounted, canned design, 4 stages with a double suction impeller and inline suction and discharge ports. Each of the four generating units has two 100% duty pumps, driven by a 1850kW 4 pole, electric motor.

Problems
For more than a few years, the life of the thrust bearing has been subjected to scrutiny after causing numerous premature failures and constant concern for the Station Operators, Maintenance Engineers and Management. The thrust bearing design was typical for the period that the pumps were manufactured, tapered back to back roller design incorporating both thrust and radial loads and the drive coupling configuration as part of the bearing cartridge.

Station Engineers had been researching the upgrade design options for a period of time, calling on the original equipment manufacturer, aftermarket service centres and bearing manufacturers for input and options to overcome this troublesome plant and work towards the best possible solution.

Contract Overview
In 2012, Eraring Energy released a tender for the upgrade project to several service providers. The project included a sizeable work scope including design and supply of a new white metal bearing cartridge with an appropriate pedestal and several other new components.

The contract specifications require maintaining the same pump drive couplings, electric motor, mechanical seal cartridge and as many of the original pump components, meaning there was substantial engineering work required by the Hydro Australia Engineers.

Contract Award
A contract of this size was sought after by several original equipment manufacturers and Hydro Australia Pty. Ltd. located in the Gippsland region at Morwell Victoria was awarded the contract late in 2012. The contract runs for a period of 4 years with the first pump installation completed in April 2013 and the final pump due for installation in 2016.

2014_10_22

Additional Requirements & Spare Pump
With the knowledge and experience of Hydro Australia with the supply of engineered spare parts, a major undertaking was to supply and a complete new discharge head, a first for Hydro Australia. The 2.5 m high and 1.7 m wide discharge head is the most significant component of the pump as it ties everything together. Other new components were manufactured by Hydro Australia including impellers, stage cases, wear rings, couplings and shafts. The new components complete with the stations spare parts, enabled a complete spare pump to be manufactured. This spare pump gives flexibility and relieves time critical exchanges and on the run maintenance. Continue reading

Increasing Capacity

Author:

Ross Bertoli, Hydro Australia, and Mark Moerke, International Power Hazelwood

Publisher:

Pumps & Systems

Date Published:

August, 2009

 

As the global demand for energy grows, power companies are working to implement new technologies that would enable them to produce more power from existing stations. The following example demonstrates how International Power’s Hazelwood power station in Australia improved the efficiency of their motor-driven boiler feed pumps to produce a higher megawatt output without burning additional fossil fuels.

 

The Growing Demand for Energy

Built between 1964 and 1971, the Hazelwood Power Station in Victoria’s Latrobe Valley originally planned to have six units producing 200 MW each. However, growing electricity demand in the late 60s prompted the approval of a proposal to add two units to the station to increase generating capacity. The eight-unit power station was producing 1,600 MW output by the early 70s; each unit generated 200 MW of power. In recent years, this power station has moved to improve its output through thermal efficiency gains and increasing each unit’s capacity by 20 MW.

 

Engineered Modifications to Improve Pump Efficiency

Having modified the turbines to use less power, the plant needed to upgrade the 11-stage ring section, boiler feed pumps to meet the newly elevated performance requirements. International Power Hazelwood (IPRH) contacted a pump aftermarket service center in the Latrobe Valley to determine if modifications could be made to seven of these pumps within a two-year time period.

Though the original pump curves implied that the pump would have sufficient head and flow to handle the increased service conditions, several factors were discovered during inspection that would determine the course of action. Due to a vane pass vibration, the diffuser vanes had been machined to correct a vane pass issue that the pump experienced early on in its life. As a result, the hydraulic performance of the diffuser was compromised, and the pump no longer matched the manufacturer’s original design. The motor size also limited the power usage.

 


Rotor Centralization was performed to improve pump efficiency

 

Continue reading

Failure Solution

Author:

Kwa Soo Teck, Phu My 3 Power Station (Vietnam), & Chandra Verma, Hydro Australia

Publisher:

Pumps & Systems

Date Published:

September, 2011

 

Phu My 3 BOT Power Station, a Vietnamese power station using combined cycle gas turbine technology and operating at 749 megawatt capacity, had been experiencing some problems with their vertical pumps. The station asked Hydro Australia to assess the damage and assist with a solution.

 

The power plant in Vietnam

 

The vertical pumps were used for the circulating water system. The impeller material was a super duplex and the product being pumped was sea water. Over a period of three years, Phu My 3 had experienced catastrophic failures with the impellers and were unsure of the cause. The first pump was installed in Sept 2003 and the first blade failed in September 2008; the second failure occurred in Sept 2009 and a third failure occurred in June 2010.

On viewing the damaged impellers, which weigh 850 kilograms, it was obvious the quality was poor. The first step in the process was to send over an engineer with a Romer Arm, a 3D coordinate measuring instrument, to reverse engineer the impeller. This data could be used to analyse the existing impeller design.

 

Continue reading