THE EXPERIENCES OF THE NEW ZEALAND FOSSIL POWER INDUSTRY WITH THE CHALLENGES OF FLOW-ACCELERATED CORROSION IN HRSGs – ISSUES AND SOLUTIONS
Author:
David Addison
Presented At:
International Conference on Flow-accelerated Corrosion in Fossil and Combined Cycle Plants with Heat Recovery Steam Generators, June 29/30 and July 1, 2010, Arlington, Virginia, United States of America
Abstract:
New Zealand is an island country in the south-western Pacific Ocean comprising two main land masses and has a total population of approximately 4.2 million people. The fossil power industry in New Zealand comprises of a combination of 1970’s and 1980’s vintage gas and coal fired conventional units, three large F Class single shaft Combined Cycle stations from different manufacturers commissioned from 1998 to 2007 all with horizontal, triple pressure Heat Recovery Steam Generators (HRSGs), and a number of small aero-derivative gas turbine/HRSG co-generation plants.
Flow-accelerated Corrosion (FAC) issues, in varying degrees, have occurred at all sites with a number of different monitoring and resolution strategies employed to ensure plant reliability and safe operation. These strategies have included operating and cycle chemistry changes, improved monitoring, increased non destructive testing (NDT), and improved specification of later units.
This paper provides a clear and concise summary of the New Zealand fossil power industry experiences with FAC in Combined Cycle Gas Turbine (CCGT) plants and future activities in relation to FAC.
CONDENSATE POLISHING AND COMBINED CYCLE GAS TURBINES – TECHNICAL AND FINANCIAL JUSTIFICATION AND APPROPRIATE TECHNOLOGY SELECTION
Author:
David Addison and Les Lloyd
Presented At:
EPRI: Ninth International Conference on Cycle Chemistry in Fossil and Combined Cycle Plants with Heat Recovery Steam Generators, June 30 - July 2, 2009, Westin Copley Place, Boston, United States of America
Abstract:
Whilst the technical justification for the inclusion of a condensate polisher for a Combined Cycle Gas Turbine (CCGT) new generation project is simple and straightforward with the benefits of condensate polishing clearly understood, very few projects worldwide are specified and constructed with a condensate polisher. This situation often arises because the robust financial justification and cost benefit analysis required for the inclusion of a condensate polisher into a project is often unable to be completed with the required level of detail to withstand the intense financial scrutiny of new CCGT projects.
Available condensate polishing technologies are reviewed with budget estimates provided for each key technology type. Technical and financial justification methodology’s for the inclusion of condensate polishers on CCGT projects are outlined and discussed. The cost of condensate polishing on a new CCGT project is shown to be approximately 1% of the cost of a standardised, new CCGT unit.
THE UNIQUE APPLICATION OF A SEPERATE BED CONDENSATE POLISHING PLANT SYSTEM (TRIPOL®) IN A 400 MW COMBINED CYCLE GAS TURBINE POWER PLANT – THE HUNTLY POWER STATION EXPERIENCE
Author:
David Addison & Les Lloyd (Veolia)
Presented At:
IEX 2008 Recent Advances in Ion Exchange Theory & Practice Conference, Cambridge, UK, 9-11 July 2008
Abstract:
The use of condensate polishing on modern Combined Cycle Gas Turbine (CCGT) power plants is often neglected due to incorrect cost benefit assumptions and short term project objectives. This has resulted in very few CCGT plants worldwide having condensate polishing plants so the short term and long term benefits of condensate polishing have not been fully realised. The application of separate bed condensate polishing on CCGT plants has, until now, been unheard of. This situation has now changed with the construction and commissioning of Huntly Power Station Unit 5, a 400 MW CCGT plant that utilises a cost effective, high performance, easy to operate, separate bed condensate polishing system (TRIPOL®) that delivers clear short term and long term benefits over the entire life of the CCGT plant.
THE EASY WAY IS ALWAYS THE WRONG WAY - HRSG COMMISSIONING AND THE EPIC STRUGGLE FOR GOOD CHEMISTRY
Author:
David Addison
Presented At:
API Power Station Chemistry Conference 25th to 30th May 2008, Sunshine Coast, Queensland, Australia
Abstract:
The easy and fast way on a Combined Cycle Gas Turbine (CCGT) project is to just forget about good chemistry. The easy and fast path will get your project built and commissioned quickly but it will then suffer from Heat Recovery Steam Generator (HRSG) and Steam Turbine related chemistry issues for the rest of it's operational life. For an operator of a CCGT unit this is not a position that one would wish to be in.
Chemistry is an integral part of the success of CCGT projects. The power plant chemist plays a vital part in the long-term future reliability of any power plant and has significant role in all phases of a CCGT project from specification to commissioning.
IMPROVING CHEMICAL PLANNING ASPECTS OF NEW GENERATION PLANT - HUNTLY E3P PROJECT EXPERIENCE
Author:
David Addison
Presented At:
2006 ESAA Power Station Chemistry Conference 5-10 March 2006 in Australia. Also published in Power Plant Chemistry Journal - 2006, 8(6)
Abstract:
Modern Engineer, Procure and Construct (EPC) contracts can, at times, lack suitable thermal power station chemistry expertise, resulting in less than best practice design choices being made. It is the responsibility of thermal power station chemists within organisations that are the clients of EPC contracts to ensure that thermal power station chemistry knowledge and good practice is utilised for new projects. This approach has been followed with Genesis Energy's new “Energy, Efficiency, Enhancement” (e3p) 385MW combined cycle gas turbine (CCGT) plant, located at its Huntly Power Station site in New Zealand. This project has also shown that the inclusion of condensate polishing for CCGT units is economically viable with significant long term benefits in terms of lower plant operating costs and improved plant reliability.
OXYGENATED TREATMENT ON 2-SHIFTING PLANTS: THE HUNTLY POWER STATION, NEW ZEALAND, EXPERIENCE
Author:
David Addison
Presented At:
2003 Electrical Power Research Institute (EPRI) International Conference on Power Station Chemistry
Abstract:
Due to concerns over Flow Accelerated Corrosion (FAC) damage at Huntly Power Station a cycle chemistry change from All Volatile Treatment [oxidising] (AVTo) to Oxygenated Treatment (OT) was trialled on Huntly Power Station unit 2. This has led to significant decreases in iron corrosion product transport rates to the boiler with corresponding observable physical changes in oxide layer morphology. Magnetite (Fe3O4) dominated FAC damaged areas showing significant material loss have changed to haematite (Fe2O3) dominated areas that are resistant to FAC damage and can be considered fully protected.
This paper describes comparisons made between corrosion product transport rates for AVTo and OT operation for both base load and 2-shifting operation along with comparisons between return to service iron corrosion product transport rates for AVTo and OT units. Also covered are oxygen injection and control system issues in relation to Economiser/Boiler dissolved oxygen (dO2) ratios at varying boiler pressures and the assessment of any copper migration from boiler water and steam touched surfaces to the high pressure (HP) turbine.
