Jose,
Your timing couldn’t be better. We just finished (literally
yesterday), a steam accumulator model that is intended to do exactly
as you suggest; store steam in a pressurized vessel for periods of low
steam production and higher load. If you search for STEAM ACCUMULATOR
online you’ll be able to see how they work. The key is you have to
store steam at a higher pressure than the load pressure to be able to
use the stored steam. This model will be part of the new TESS
Libraries v18 package but can be made available as a stand alone
component now if needed. Let me know and I can get you a quote.
As for Type 22, I’ll start with my usual questions when people ask
about controls:
1) Are you using a small timestep?
2) Do you have capacitance in your solar loop (pipes etc) to dampen
the oscillations?
If you do then I’d like to know which collector model you are using?
Many of the TESS ones have an option for internal controls where you
can set the desired outlet temperature.
Jeff - TESS LLC
Sent from my iPhone
On Sep 14, 2019, at 8:31 AM, José María Roca via TRNSYS-users
<trnsys-users@lists.onebuilding.org> wrote:
Hello community,
I’m trying to model solar steam generation and I was wondering if
there is some kind of storage that could hold steam and saturated
water, that could act as buffer in case the radiation falls for a
small gap of time (1h, 2h, etc).
I’m using to generate steam the type 637a HRSG using as hot source
pressurized water from the solar field. I looked into the flash tank
but it doesn’t have volume parameters, so this can’t hold steam and it
works pretty much as the 637. Am I right?
On the other hand regarding the second part of the question, I’m using
the type22 to modulate the speed of the pump in the solar field, to
try and keep an outlet temperature at a certain value. The problem I’m
having is that this controller in some (many) occasions goes into
“stuck at previous value”, controller status value 17. This in turn
makes the colector output temperature go to the maximum value and no
flow goes through the solar field, until some time steps in the future
it starts working again. I can’t figure out why this happens, the only
thing I can think is that as the direct radiation falls in those time
periods perhaps de controller can’t resolve a pump flow to keep the
temp at the setpoint, but this makes the temperture to raise to
maximum, seems odd.
Thanks for reading and for any comments.
Best,
José M. Roca
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