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Re : Re: Re : Re: Re : Re: [EnergyPlus_Support] question about AirLoopHVAC



Thanks Richard for your reply.
I will try to implement it in this way and come back to you if needed...
Herve


Message original Re : Re: Re : Re: Re : Re: [EnergyPlus_Support] question about AirLoopHVAC

De : Richard Raustad <RRaustad@xxxxxxxxxxxx>
A : EnergyPlus_Support@xxxxxxxxxxxxxxx
Date : 2011-02-24 18:29:10


 

You would first have to get the regeneration branch isolated (i.e., not connected to the exhaust node of the mixer). I guess you could just set it up to have an inlet that is an outside air node. Of course, there would be 0 flow rate through this branch.

Then you would need to get the flow rate through this isolated branch to match the mixed air flow rate. The EMS could do this.

After that, you would need to use the EMS to calculate the "mixed air condition entering the regeneration branch" and place those conditions at the regeneration inlet just as you did for the flow rate.

On 2/24/2011 12:03 PM, Brouchery Herve wrote:

OK but in this case the mixed air stream will be 100% outdoor air.

The test case I would like to implement is the following:
- mixed air : 90% return air (from zone) and 10% outdoor air
- relief air : 10% return air (from zone) and 90% outdoor air

Do you think this is possible to implement?

Many thanks
Herve

Message original Re : Re: Re : Re: [EnergyPlus_Support] question about AirLoopHVAC

De : Richard Raustad <RRaustad@xxxxxxxxxxxx>
A : EnergyPlus_Support@xxxxxxxxxxxxxxx
Date : 2011-02-24 17:36:21


 

A second mixing box is not allowed.

You kind of said it in your question, "this only happens when the outdoor air fraction is 1". The mixed and exhaust air steam flow rates can only be the same when you are providing 100% outdoor air. That's the key. Set your minimum outdoor flow rate to be the same as the max supply air flow rate and see what happens.

On 2/24/2011 11:25 AM, Brouchery Herve wrote:

Hi Richard,

I come back to you on this topic. I succeeded to connect the exhaust stream and I am now able to run a complete simulation.

My problem now is that I would like to have the same flow rate in both branches: the process branch and the exhaust branch. In the file I sent (please refer to attached file Dunkle_cycle_v1.pdf), this occurs only when the outdoor air fraction is 1 (in the file, when x=1). For any other fractions, the flow rates become unbalanced.

Do you think adding another outdoor air mixer could solve the issue (please refer to the file Dunkle_cycle_v2.pdf)? If no, could you please suggest me a way to solve it?

Many thanks for your help!
Herve


Message original Re : Re: [EnergyPlus_Support] question about AirLoopHVAC

De : Richard Raustad <RRaustad@xxxxxxxxxxxx>
A : EnergyPlus_Support@xxxxxxxxxxxxxxx
Date : 2011-02-16 17:15:03


 

I am fairly sure that will work. At least the code seems to allow it. You will need to attach your input file and send to:

energyplus-support@xxxxxxxx

or submit a ticket through the help desk web site at:

http://energyplus.helpserve.com/

On 2/16/2011 11:01 AM, Brouchery Herve wrote:

Hello,

I have tried to model the attached AirLoopHVAC system under Energy Plus (see attached file "Dunkle_cycle.pdf ").
I obtained the following error : Invalid Air Loop Component Type = "HEATEXCHANGER:AIRTOAIR:SENSIBLEANDLATENT". Why does Energy Plus have such limitation? Do you know any workaround that I could use?

Thanks in advance for your help.
Hervé

-- 
Richard A. Raustad
Senior Research Engineer
Florida Solar Energy Center
University of Central Florida
1679 Clearlake Road
Cocoa, FL  32922-5703
Phone:   (321) 638-1454
Fax:     (321) 638-1439 or 1010
Visit our web site at: http://www.fsec.ucf.edu

UCF - From Promise to Prominence: Celebrating 40 Years

-- 
Richard A. Raustad
Senior Research Engineer
Florida Solar Energy Center
University of Central Florida
1679 Clearlake Road
Cocoa, FL  32922-5703
Phone:   (321) 638-1454
Fax:     (321) 638-1439 or 1010
Visit our web site at: http://www.fsec.ucf.edu

UCF - From Promise to Prominence: Celebrating 40 Years

-- 
Richard A. Raustad
Senior Research Engineer
Florida Solar Energy Center
University of Central Florida
1679 Clearlake Road
Cocoa, FL  32922-5703
Phone:   (321) 638-1454
Fax:     (321) 638-1439 or 1010
Visit our web site at: http://www.fsec.ucf.edu

UCF - From Promise to Prominence: Celebrating 40 Years