4313 Nebraska Court
Pomfret, MD 20675
USA
Phone: (301) 934-5605
Fax: (301) 934-5606
Email:
Copyright (c) 2009 Jonas, Inc. All Rights Reserved
Specializing in Sampling and Instrumentation, Corrosion,
Water and Steam Chemistry, and Failure Analysis
Serving the power industry since 1983
Steam Cycle Water Chemistry Commissioning Guidelines
Water and steam chemistry and corrosion control is often a neglected area during the storage, erection, and commissioning of the equipment
when building new units. There are no industry-wide guidelines.
The lack of readiness of the related equipment, accumulation
of corrosion products, and often the use of incorrect water treatment chemicals can lead to significant delays of commissioning and
costly delays in transferring the steam cycle to the customer. One day of delay may cost as much as a quarter million dollars
and delays of several weeks are not uncommon. In addition, bad water chemistry caused by condenser leaks, air inleakage, accumulation
of corrosion products, and inappropriate chemicals may cause scale and deposits and permanent corrosion damage; particularly to the
boiler or HRSGs and turbines.
- condenser leak leading to cycle contamination by seawater
- destructive overspeed of turbine due to high boiler carry-over
and valves stuck open
- pitting and stress corrosion cracking of stainless steel feedwater heater tubes due to contamination
during storage and erection
- pitting of turbine blades during storage, leading to their replacement
- improper operation
- no training and guidelines
- system corrosion because water chemistry control was not functioning
Examples of Encountered Problems
1 Review of Cycle and Component Design
2 Preservation during Manufacture, Transport, Storage, Erection, and Layup
3 Water
Chemistry Control and Management
4 Training of Operators and Chemists
5 Manuals
6 Inspections: Methods and Results
7 Pre-Operational Cleaning, Hydro Tests
8 Maintenance Procedures
9 Pre-steaming Checks - Boiler, Turbine, Condensate
Polishing, Send-out Steam System, GT Injection
10 Performance Testing
The Commissioning Guidelines are Customized Based on Cycle Design and Type of Operation and can include:
10.1 Steam Purity/Carry-over
10.2 Boiler Hideout
10.3 Makeup/Water Storage
10.4 Condensate Polishing/Regeneration
10.5 Deaeration
10.6 Chemical Addition Equipment
10.7 Condenser:
Leaks, Deaeration
10.8 Send-out Steam and Return Condensate
10.9 GT Injection System
10.10 Iron (and Cu) Transport
10.11
Sampling and Monitoring Equipment
10.12 System Corrosion
11 Cooling Water System
12 Chemical Discharges/Disposal
13 Chemical Laboratory
14 Commissioning Schedule
15 Safety Issues
16 Checklist
- a list of tasks to be completed and signed off as a record for the transfer of the unit to the customer
