why feed control valve providing after economiser for some boilers (WHRB), and what is diff between WHRB&HRSG

 

Raj... for "What's in a Name?" see Control.Com Thread # 1026145196.

Regards, Phil Corso

 

One of the main reasons to have the feed control valve after the economiser is to protect the economiser itself. I will explain:

In the setups where the control valve is before the economiser, when this valve closes the economiser attains the boiler pressure. If the temperature of the exhaust gases reaching the ecnomiser is higher than the economiser saturated water pressure (temperature) the water inside the economiser starts boiling, turning the economiser into an evaporator. In the worst of cases it will boil off and run dry. To prevent or minimize this risk, the control valve is placed after the economiser such that the economiser is always at the feedwater pump pressure. This is mainly applicable to the situations when the boiler is still being heated up and is not up to working pressure. In such situations the risk of boiling of the water in the economiser is much higher.

 

ok friends thanks for reply one more question: What is the diff between WHRB & HRSG

 

>What is the diff between WHRB & HRSG<

They are spelled differently. There is no functional difference.

 

True, however it seems that WHRB mainly refers to boilers which produce saturated steam, and HRSG refers to boilers that produce SH steam. But again as Otised stated, there is no functional difference between them. Somebody just decided to use the two acronyms to differentiate between the two.

 

As otised says, a rose by any other name would still smell as sweet.

WHRB: Waste Heat Recovery Boiler
HRSG: Heat Recovery Steam Generator

The two terms are synonymous and interchangeable.