Re: [TRNSYS-users] Solar Collector Series and parallel

[Jeff Thornton <thornton@tess-inc.com>]

Think of your array as one big collector.  If we fix the total flow rate and solar radiation, would it matter if we broke that collector into 3 pieces along the flow direction and connected them in series?  Of course not.  Take that a step farther.  Break each of those 3 pieces in half in the other direction such that we have two parallel paths of 3 collectors each.  Hopefully you’ll agree that again we’ll get the same answer.  Now if we take all 6 of these pieces, break them apart and hook them up all in series (same total flow and solar) such that we have 6 in series we will again get the same answer.  Yes it’s a longer path but the flow through each collector is now higher and in the end it cancels out.  But therein lies the answer to your problem.  You wouldn’t pump those individual collectors at a rate that is 6x their individual expected flow rate - the pressure drop would be tremendous.  So you have to figure out the array flow rate that’ll give each collector what it expects.  

Array Flow Rate = Individual Collector Flow Rate x # Collectors / # Collectors in Series per Parallel Path

If you use that approach you’ll find that as the flow rate changes with each different arrangement your resultant outlet temperatures will also change.

Jeff

Sent from my iPhone

> On Feb 8, 2018, at 3:52 AM, maverickxxx1991 via TRNSYS-users <trnsys-users@lists.onebuilding.org> wrote:
> 
> Hey,
> 
> I’ve searched for it by different terms but didn’t find any openable diagrams and explanation. Can you please send me a link?
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