[esp-r] Fw: Modelling Phase Change Materials

[Dariusz Heim]

Hallo Nuno,
 

About the first part of your e-mail, you must be right. For PCM I still use my old version

from 2001. During the later modifications ESRU must done some small changes in the

code. Thank you for your discovery where the bug is. I try to change it for the new release.

 

About the second part of your e-mail, I am not sure if I understand you well. In multilayer

construction database it is necessary to define the partition, like wall, floor etc. On of the

layer in that construction should be defined like a PCM composite. However on the level of

multicon dbs you define it as a ordinary material (gypsum, concrete, ceramic) with

corresponding sensible heat. The latent properties of the material you defined in spm file.

The discretization (the thickness of the layer or division the pcm into more layers) effects

on the accuracy of temperature distribution inside the construction. >From the energy point

of view it is less important.

As far as I know in ESP-r the finite differences method allowed to define each layer of the

construction with three nodes. One middle node and two boundary nodes. The idea was

similar to the PV modelling which was developed by Nick Kelly from Strathclyde in 1998.

Please, look at his PhD Thesis which must be available on the web side:

http://www.esru.strath.ac.uk/

and than Books and PhD Thesis. There is a detailed description how the "material properties

substitution" works.

 

I will be very happy, if you have additional questions or comments.

 

with the best regards,

Darek

  ----- Original Message ----- 
  From: Nuno Fernandes 
  To: 'Dariusz Heim' 
  Sent: Thursday, October 26, 2006 12:11 PM
  Subject: RE: [esp-r] Modelling Phase Change Materials


  Hello Mr. Heim,

   

  Once again thanks for your reply. 

   

  It seems that the problem that I have related is crossed. The initial problem occur when defining the phase change material in the advance components module, a incorrect value of the parameter "Latent Heat member b"  was written in the folder with the properties of the PCM. To cross this, I have manually introduced the value in the folder and everything work's properly. Well not everything and this is my newest problem. 

   

  I have read some of yours publications from IBPSA Conferences and an ASHRAE Transaction where you describe your work. It seams, when modelling PCMs, its necessary to define the layer properties in the multilayer constructions file, until here no problems. But when defining the active material (PCM) in the advanced components module it is necessary to define the node were it is associated. Well my problem starts here. My reading conclusions indicate that the proper way of putting them in the layer is in the middle node but, the system, by default, only define two nodes for each layer.

   

  How can I tell the system to define, unless 3 nodes in each layer? I read too, that a better subdivision of the layer will increase accuracy.

   

  Thanks in advance.

   

  Best regards,

   

  Nuno Fernandes

   

   

   

   

  ################################################# 

    Nuno Tiago Afonso Fernandes

   

    Universidade de Aveiro

    Departamento de Engenharia Mecânica

    Campus Universitário de Santiago  

    3810-193 Aveiro  

    Portugal

    Tel.: +351 234 370 830

    nuno.fernandes at mec.ua.pt

    www.ua.pt

  ##########################################################

   

   


------------------------------------------------------------------------------

  From: Dariusz Heim [mailto:dariusz.heim at p.lodz.pl] 
  Sent: sexta-feira, 13 de Outubro de 2006 17:41
  To: Nuno Fernandes; esp-r at lists.strath.ac.uk
  Subject: Re: [esp-r] Modelling Phase Change Materials

   

  Dear Nuno,

   

  I was working on PCM in ESP-r a few years ago and it works.

  I not sure how it is going just now. Please, let me know

  what is your version of ESP and than I will try to help you.

   

  with best regards,

  Darek

    ----- Original Message ----- 

    From: Nuno Fernandes 

    To: esp-r at lists.strath.ac.uk 

    Sent: Friday, October 13, 2006 4:15 PM

    Subject: [esp-r] Modelling Phase Change Materials

     

    Dear all esp-r users,

     

    I'm starting to model a project, which will include in its constructions, phase change materials. 

     

    My question is related with the modelling of PCMs in esp-r. Does anyone have notes or tips to give me? I tried to model it but I haven't any good resultsL. Can someone help me?

     

    Thanks in advance.

     

    Best regards,

     

    Nuno Fernandes

     

     

    ################################################# 

      Nuno Tiago Afonso Fernandes

     

      Universidade de Aveiro

      Departamento de Engenharia Mecânica

      Campus Universitário de Santiago  

      3810-193 Aveiro  

      Portugal

      Tel.: +351 234 370 830

      nuno.fernandes at mec.ua.pt

      www.ua.pt

    ##########################################################

     

     


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