10 replies to this topic

[jeffr]

As part of energy efficiency reviews for operating oil and gas production installations, the performance of fired heaters used for supplying process heating is often of prime importance. Many are either fired water bath heaters with natural draft (smaller capacity) or vertical induced draft (larger types). Only a small percentage appear to be forced draft. What I am having difficulty in determining is the achievable thermal efficiencies of different types and if retrofits of existing units is likely to be economically viable to improve energy performance. In short:

Thermal efficiency of fired heaters for glycol reconcentrator units
natural draft bath type heater
forced draft bath heater (simple mechanical linkage for air fuel ratio control)

Thermal efficiency for fired heaters for hot oil heating units
Induced draft vertical unit
Forced draft vertical unit

Any rules of thumb for economic approach to design based on thermal capacity would be appreciated, i.e. below x MW thermal forced draft not realistic.

Regards

JeffR

[Robert Montoya]

Dear Jeffr in the attachment file is the article to check and performance fired heater.

Attached Files

•  check fired heater performance.pdf   3.64MB   7135 downloads

[breizh]

Consider this resource too .

Breizh

[Heater Guru]

API-560 provides complete details for calculating thermal efficiency of fired heaters. Please send me an email and I will email you our thermal efficiency calculator to you.

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[Ahsan67]

jeffr,

API-560 provides a complete guide to calculate effieciency of fired heaters for now i am facing a problem in uploading sheets which i made accordingly API-560 for calculating effieciencies for refinery fired heaters, which requires the following data


fuel gas composition(or provide LHV or HHV) & for oil fired heaters carbon-hydrogen rartio (or provide LHV or HHV)
Amount of Atomizing steam (pounds per pound of fuel or assumed) in case of oil fired
Relative humidity , Vapour Pressure of water at that Temperature (simply from steam table)
percent of O2 leaving from stack(O2 Analyzer)
Then get amount of heat loss from stack with flue gases(CO2,N2,H2O,Excess Air) which we can find from relation given in graph in API-560

Then the final step is to find the heat efficieny by simply dividing{ (LHV+amount of heat possesed by fuel because of temprature at the inlet+Air Temprature at the inlet+amount of heat possesed by steam at the inlet) - (amount of heat releaed at stack with flue gases)-( 1% heat loss assumed in radiation section) divided by (LHV+amount of heat possesed by fuel because of temprature at the inlet+Air Temprature at the inlet+amount of heat possesed by steam at the inlet)

Regards
Ahsan

Edited by Ahsan67, 20 November 2012 - 12:26 AM.

[ali.m.garadi@gmail.com]

is there any Excl sheet that we can perform heater efficiency ?

[thorium90]

The following site is useful

http://www.jehar.com/heater.htm

 

Although google curiously black lists it for no reason..

[sajju]

Dear all

 

Do any one have the simulation for indirect water bath heater in chemcad. how to do that send me with an example simulation problem if possible.

[avedhesh]

API-560 provides complete details for calculating thermal efficiency of fired heaters. Please send me an email and I will email you our thermal efficiency calculator to you.

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Dear Sir, I am comparitively new and trying to find calculators/calculation starting from Fuel (oil/gas) compositions to Flue gas compostions and emssions values, air flow requirement etc. Can you help me on this.

 

Thanks

[BaderD]

Hey guys,

 

If possible, I need a calculator for the thermal efficiency of fired heat exchangers. It would be very helpful for my project. Thanks in advance.

 

Regards,

[breizh]

BaderD ,

Why don't you try to do your own work with all the materials given and share with us after ? It will be beneficial for all the forum members .

 

Good luck.

 

Breizh