## Featured Articles

Check out the latest featured articles.

## New Article

Product Viscosity vs. Shear

## Featured File

Vertical Tank Selection

## New Blog Entry

Low Flow in Pipes- posted in Ankur's blog

2

# Fired Heater Fuel Gas Cascade With Temperature

2 replies to this topic
|

### #1 zayedalshuhoumi

zayedalshuhoumi

Junior Member

• Members
• 27 posts

Posted 07 March 2021 - 10:00 AM

How do you calculate actual flow rate of Fuel Gas from the flow meter reading?
In our process plant we have Fuel Gas FTs which gives us reading in Nm3/hr and we want to calculate from this reading actual fuel gas flow taking into account temperature, pressure and specific gravity corrections.
Which is the most accurate formula for calculating flow rate? What are the best practices followed by other refineries in order to calculate the fuel gas flow, do they apply temperature and pressure correlations? Pressure or density which is better to take in .
Some time the actual fuel gas link with LHV to more accurate.

### #2 jayari

jayari

Veteran Member

• Members
• 30 posts

Posted 07 March 2021 - 01:29 PM

If you have a flow rate in normal cubic meters per hour, you can covert that to a mass flow rate with the density of the fluid at whatever temperature and pressure you (or the instrument manufacturer) have defined as the normal conditions. That is the true mass flow rate going through the meter and then you can covert that to actual volume flow with whatever density data you have.

Edited by jayari, 07 March 2021 - 01:29 PM.

### #3 zayedalshuhoumi

zayedalshuhoumi

Junior Member

• Members
• 27 posts

Posted 08 March 2021 - 01:00 PM

I agree with your comments.analyser specific gravity(AI20) ,out put of Fuel gas pressure PI023(kg/cm2g), Temperature of Fuel gas TI012 © and Fuel gas flow rate FI031(kg/hr) goes input to Heat rate (Fuel gas flowrate compensation block Arithmetic control block (FY015).Another out put from analyzer goes input to another block (AY024)calculates the LHV of the fuel gas based on its composition . The output of this block goes to Arithmetic control block QY013which is calculates the actual heat rate of the fuel gas stream plus input from.if only output from analyzer (AI20) goes to to FY015 it work fine. Why the put another output from analyzer to QY013 and why the called LHV because from same analyzer there is any difference?