Faced with budgetary and personnel constraints, many plant managers must make difficult choices to ensure their steam-water analysis system can provide the critical data they need to protect their equipment. Yet, improperly installed or retrofitted SWAS can have far-reaching maintenance and downtime effects, leaving you without necessary visibility.
Common Swas challenges
The Electric Power Research Institute (EPRI), American Society of Mechanical Engineers (ASME), and the International Association of the Properties of Water and Steam (IAPWS) require continuous online analysis of all parameters that minimize corrosion and deposit formation in the boilers or turbines of power plants.
A steam and water analysis system (SWAS) conditions, analyzes and monitors steam and water's chemical properties to generate electricity. A well-designed SWAS will maximize efficiency and output while protecting plant assets, operators and the environment. Good analysis starts from the point of sample extraction and includes proper sample transport and conditioning so that each analyzer receives a consistent, reliable sample that is representative of the process. Without this, analyzer measurements are not trust worthy.
Common SWAS challenges that may require a new install or retrofit include:
- Some systems already have been retrofitted once from their original design
- As SWAS equipment ages, performance and efficiency can dwindle
- Plant chemistry requirements might have changed since the SWAS was originally specified
- Plant managers might need to consult the plant's chemistry program before selecting new analyzers or the number of sample points
- Current conditioning systems might not be effective
Ensure proper installation or retrofit
1. Start with technical design specs. Your technical design specification is the first step in designing a SWAS that operates accurately, reliably and safely under the specified operating conditions. A well-written SWAS specification will include specific equipment details (such as materials of construction, performance specs and ratings) and deal with issues like vibration, wear, corrosion or other performance issues.
2. Automate flow control. Power plants that frequently cycle or have sliding pressures require technicians to manually adjust the variable pressure-reducing element in sample panels to maintain flow and EPRI-recommended sample velocity.
Mount an automated flow controller on high-pressure reducing valves for fully automatic operation of the pressure reducing valve to maintain consistent sample flow, regardless of fluctuating pressure conditions. Or choose a fully automated sample conditioning system to provide automatic startup (including blowdown), flow control and shutdown.
3. Streamline sampling efforts. Automated sample sequencing ensures proper analysis frequency and saves time during the proposal evaluation because it quickly identifies preferred solutions. Allowing sample sequencing will also reduce the number of analyzers and mitigate operational, calibration and maintenance costs.
4. Leverage smart sensors and new technology. SWAS can contain a variety of online chemistry parameter analyzers, including smart chemistry alarms. These sensors monitor the signals generated by analyzers to provide real-time intelligence about what's happening and what steps need to be taken to resolve the chemistry event or analyzer issue.
Other systems in the plant, including water treatment, cooling water or GT cooling, utilize similar technology to measure steam purity samples, such as pH, conductivity and silica. The mechanical installation of these systems is akin to a SWAS installation, which can add benefits to your entire system.
5. Add an extended warranty. Some manufacturers offer extended warranties on their OEM equipment if a monthly service agreement is in place at commissioning.
6. Implement training. Training staff to properly operate these different systems is paramount, secondary only to the routine maintenance and calibrations. This insight will ensure that safety guidelines are followed and your SWAS is meeting your process specifications.
Proper Sampling Knowledge And Experience
By protecting plant assets, proper cycle chemistry can help you confidently ensure your plant operators' safety and maintain uninterrupted production. The net result is more precise water and steam chemistry and fewer chemistry-related failures caused by corrosion and contamination. Learn how Sentry ProShield Install and Retrofit services can help your facility.