Understanding the Purpose and Placement of a Feed Water Heater's Drain Cooler

[ashoksmulpuri]

1. What is the function of drain cooler in a feed water heater and is there any reason that it is integral within the heat exchanger but some times it is also placed outside the heater.

Homework Equations

3. ok i got to know the function of a drain cooler.it sub cools the extraction steam. but why is it important i couldn't understand. i couldn't get the answer for the construction of drain cooler(wheteher it is integral with the heater or outside the heater.)

 

[Valkarie]

A drain cooler is important because it helps to reduce the temperature of the extracted steam from the feed water heater, which in turn helps to improve the thermal efficiency of the heater. When the drain cooler is placed outside the heater, it allows for more flexibility in terms of the location of the drain cooler, as well as the ability to control the temperature of the extracted steam more precisely.

 

[Mene]

I can provide some insight into the purpose and placement of a feed water heater's drain cooler. The drain cooler serves the important function of subcooling the extraction steam, which helps to increase the overall efficiency of the power plant. This is because the cooler steam is denser and therefore contains more energy that can be used to heat the feed water.

The placement of the drain cooler can vary depending on the design of the feed water heater. In some cases, it may be integral within the heat exchanger, meaning it is built into the same unit as the heater. This allows for a more compact design and can save space in the power plant.

However, there may be reasons why the drain cooler is placed outside the heater. One possible reason is to prevent thermal stresses on the heat exchanger tubes. The temperature difference between the hot extraction steam and the cooler feed water can cause expansion and contraction of the tubes, which can lead to damage over time. By placing the drain cooler outside the heater, this temperature difference is reduced, minimizing the stress on the tubes.

In addition, placing the drain cooler outside the heater can also allow for easier maintenance and repair, as it can be accessed separately from the heat exchanger.

Overall, the placement of the drain cooler depends on various factors, including the design and efficiency goals of the power plant. But its function remains the same - to subcool the extraction steam and increase the efficiency of the feed water heater. I hope this helps to clarify the purpose and placement of the drain cooler in a feed water heater.