[Equest-users] Cogeneration follies

Marc Wachter marc at wachterbsd.com
Thu Jan 1 16:15:36 PST 2009


I too have been struggling quite a bit understanding the model behind the
cogeneration system - specifically a gas turbine. We have been doing a
number of facility assessments recently and while we set the meter to
"Maximum Output" it is clear from the load profile that the turbine is not
running at peak load nor is the hot water loop picking up all of the
rejected heat.

I am still trying to get a report out of DOE for generation output as well.
I will keep you posted on my developments - hopefully I will have something
out of the four day weekend.

Happy New Year!

Best regards,
Marc Wachter

Marc W. Wachter
Wachter & Associates Engineering
marc at wachterbsd.com
600 Jessup Road
Suite 104
West Deptford. NJ 08066
tel: (856) 686-0900
fax: (856) 686-0901

John Wrote:

What a way to end a year (besides all the other stuff going on in the
world). Struggling through eQuest once again.

Has anyone really tried to work the cogeneration (generator) portion of
eQuest? Although cogen doesn't pay back like it used to, I deemed it
something I should reacquaint myself to during the current lull in projects.

I took a small hotel with default profiles and loads. I also ran the same
building with a 400 kW gas fired reciprocating generator (400 kW pulled from
the air). I wanted to optimize the generator size and/or time of operation
for this mythical building.

For the base case, I can develop the 8,760 hours of electric usage in hourly
day and transfer this to an Excel spreadsheet. This gives me a Histogram (I
believe) of the intensity of load for each hour of the day
(365 1 AMs, 365 2 AMs, etc). This used to be a DOE-2.1E standard printout,
but has disappeared from Version 2.2.

I then tried to find a hourly parameter that shows me either the generated
electric load, or the electric load remaining after cogen is applied. I
cannot seem to find such a parameter.

Has anyone else played with cogen in eQuest?

My thanks to all who have contributed to this Forum over the years. As they
say "Keep those cards and letters coming". I read all posts. I just cannot
respond answers for them all (assuming I HAD an answer). But something is
always learned.

Keep 'em flyin..



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