Exhaust/Heat Recovery
Exhaust/Heat Recovery
(OP)
Hi All,
I'm new to the forum, and also a recent college graduate who has taken on a job as a Plant Engineer. I'm looking for some guidance on a project idea I had.
At my facility, we discharge (waste) approximately 200 million BTU/hr of hot air exhaust into the atmosphere. I was trying to come up with an idea of the best way to recover this exhaust and reuse for heat, etc. I was curious if anyone has done a project similar to this or if anyone had any ideas on how to use this exhaust.
Thanks in advance,
Joe
I'm new to the forum, and also a recent college graduate who has taken on a job as a Plant Engineer. I'm looking for some guidance on a project idea I had.
At my facility, we discharge (waste) approximately 200 million BTU/hr of hot air exhaust into the atmosphere. I was trying to come up with an idea of the best way to recover this exhaust and reuse for heat, etc. I was curious if anyone has done a project similar to this or if anyone had any ideas on how to use this exhaust.
Thanks in advance,
Joe





RE: Exhaust/Heat Recovery
The problem is where do you use the energy and is the vent stream at a temperature high enough to use it somewhere.
RE: Exhaust/Heat Recovery
My projects have included water heating, methanol recovery, treater feed pre-heating amongst quite a few.
Look around in your plant and the operational conditions for the processes that require heat.
Something like this might make you stand out as a hero or as a fool, depending on the sucess of the recovery (both, process wise and $$$).
RE: Exhaust/Heat Recovery
In our plant, we use kettles to cook the free moisture out of FGD and a kiln to dry wallboard. It might be best served to reuse this heat to keep these kettles and kiln temps up.
RE: Exhaust/Heat Recovery
200 MMBTU/h is substantial but quite useless if you have nothing colder you need to heat.
RE: Exhaust/Heat Recovery
One nice use for waste heat is absorption chilling. I'm sure you have a demand for chilled water in your facility. A waste-heat absorption chiller will generate 'free' chilled water for comfort, or process cooling.
RE: Exhaust/Heat Recovery
Here is an approximation of the maximum inlet exhaust gas temperaure that would keep the fin tube in steel material. Otherwise the fins would need to be the more expensive 409ss material. This based on the above mentioned fin configeration.
Tg = 1090 -0.23Bt
where:
Tg is maximum gas temperature in F.
Bt is boiling temperature in F.