The boiler feedwater system has a major impact on the overall plant efficiency and performance. Poor control of the boiler feedwater can cause level in the boiler to overflow and dumping of the valuable treated feedwater. In addition, the boiler may trip resulting in unplanned plant shutdown that could impact financial performance of the plant.
In the normal range of plant operation, the boiler feedwater regulator experiences high flow rates with low differential pressure. However, during startup, this valve experiences low flow rates with very high differential pressure, which can cause severe cavitation damage.
Below is a link showing how the boiler feedwater control can be optimized by enhancing the control valve performance.
http://www.documentation.emersonprocess.com/groups/public_valvesprodlit/documents/case_history/d351913x012.pdf?&xBusinessUnit=Fisher%20Controls%20Valves%20Division
Has anyone experienced similar valve performance problem?
There was a similar problem in one of the power plant in Thailand. The customer had trouble maintaining their boiler water level, which resulted in the loss of treated water due to the water blowout. Through investigation, the boiler feedwater regulator were found to be the source of the issue. Not only did it cause unplanned shutdown, the customer had to keep repairing the valve trim damage.
For more information on this case, you can read up more about it in the case history below
http://www.documentation.emersonprocess.com/.../d352088x012.pdf
From this case, it showed a proper valve solution can help to minimize plant operation disruptions and keep the maintenance cost to a minimum. The cost savings can be quite substantial to the plant.
In reply to Marlin:
Indeed. Thanks Marlin, for sharing on how Fisher Protected Inside Seat helped to enhance performance of the Boiler Feedwater System.
Furthermore for Power Plants, it is important to have the plant available all time to avoid contract penalty.
In reply to Qian Xi:
Thanks for sharing this great information Qianxi & Marlin.
I would think that in general, most plants (be it O&G, Refinery, Chemical etc) would have a power utility plant in which a boiler feedwater valves could be found. Hence, there exists a great potential for our customer to maximize their plant efficiency and operating profit. Happy Selling.
Dear Quian Xi,
You didn’t estate any source cause of foreign particle in the system .What action you have taken to prevent this to damage again.
Is this system is scale free? Please add some feed water company (like NALCO Chemical CO) person to add more input in this regard .
So that customer can get complete solution for this type of problem of erosion, corrosion and scaling in the systems and also helpful to you also……….and can be solves so many other related problems also
Thanks & Regard
Lalit Mohan Kothari
“Dream and dedication makes powerful combination ”
In reply to Lalit Mohan Kothari:
Hi Lalit Mohan Kothari,
Thank you for the feedback.
The presence of foreign particles in the boiler feedwater system may be from various sources. Improper blow down techniques in new plant, iron oxide from piping system and degradation of upstream equipment in older plants can also result in debris/particles being cycled to the feedwater. Generally in boiler feedwater application, a black buildup may be magnetite. A red buildup may be hematite. Magnetite forms when little to no oxygen is present in the system and hematite will form in areas where oxygen levels are a little higher.
Indeed, water treatment methods are essential to reduce the magnetite/hematite buildup. However, even with very good water treatment, there may still be some light particles buildup in the system over time. A simple upgrade in the valve trims will help to prolong the seat life and enhance performance.
Thank you.