Unmet Hours - RSS feedhttps://unmethours.com/questions/Question-and-Answer Resource for the Building Energy Modeling CommunityenTue, 03 Mar 2020 17:59:25 -0600To model PCM hysteresis in EnergyPlus, what are the high/low temp difference of freezing/melting curves?https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/ I read the EnergyPlus input output reference to see what are the inputs for modeling PCM hysteresis, but I can't understand what is the input for Low Temperature/ High Temperature Difference of Melting / Freezing Curve. Can someone explain in a graphic way what these fields mean? Thanks in advance for your help.Fri, 26 Apr 2019 11:07:30 -0500https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/Comment by ZeyadAmin for <p>I read the EnergyPlus input output reference to see what are the inputs for modeling PCM hysteresis, but I can't understand what is the input for Low Temperature/ High Temperature Difference of Melting / Freezing Curve. Can someone explain in a graphic way what these fields mean? Thanks in advance for your help.</p>
https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?comment=40643#post-id-40643I am looking for the same information. Can anyone help, please. Your cooperation is highly appreciated. Thank you.Mon, 07 Oct 2019 21:26:35 -0500https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?comment=40643#post-id-40643Answer by Fan for <p>I read the EnergyPlus input output reference to see what are the inputs for modeling PCM hysteresis, but I can't understand what is the input for Low Temperature/ High Temperature Difference of Melting / Freezing Curve. Can someone explain in a graphic way what these fields mean? Thanks in advance for your help.</p>
https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?answer=42880#post-id-42880I think I have figured out what these mean. If we look at the phase transmission in the following picture(A heat flux-temperature curve, and it could also be viewed as a Cp-Temperature curve), we will get what these inputs mean.
Btw, Enthalpy-temperature curves could be calculated by integrating the Cp-Temperature curve using the following Equations.
![image description](/upfiles/15819733944737864.png)
![image description](https://www.researchgate.net/profile/Dawei_Yu/publication/278967001/figure/fig10/AS:614371164160032@1523488908960/Repeated-tests-for-the-determination-of-the-melting-temperature-of-Ag-by-DTA.png)Mon, 17 Feb 2020 15:03:32 -0600https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?answer=42880#post-id-42880Comment by andresgallardo for <p>I think I have figured out what these mean. If we look at the phase transmission in the following picture(A heat flux-temperature curve, and it could also be viewed as a Cp-Temperature curve), we will get what these inputs mean.
Btw, Enthalpy-temperature curves could be calculated by integrating the Cp-Temperature curve using the following Equations.
<img alt="image description" src="/upfiles/15819733944737864.png"></p>
<p><img alt="image description" src="https://www.researchgate.net/profile/Dawei_Yu/publication/278967001/figure/fig10/AS:614371164160032@1523488908960/Repeated-tests-for-the-determination-of-the-melting-temperature-of-Ag-by-DTA.png"></p>
https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?comment=42898#post-id-42898Thanks for taking the time to explain this. Can you be more clear, what is Exo and Endo in the graph? In the picture you sent, what are the inputs for Low Temperature/ High Temperature Difference of Melting / Freezing Curve? It's still not clear for me.Tue, 18 Feb 2020 08:59:02 -0600https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?comment=42898#post-id-42898Comment by Fan for <p>I think I have figured out what these mean. If we look at the phase transmission in the following picture(A heat flux-temperature curve, and it could also be viewed as a Cp-Temperature curve), we will get what these inputs mean.
Btw, Enthalpy-temperature curves could be calculated by integrating the Cp-Temperature curve using the following Equations.
<img alt="image description" src="/upfiles/15819733944737864.png"></p>
<p><img alt="image description" src="https://www.researchgate.net/profile/Dawei_Yu/publication/278967001/figure/fig10/AS:614371164160032@1523488908960/Repeated-tests-for-the-determination-of-the-melting-temperature-of-Ag-by-DTA.png"></p>
https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?comment=43144#post-id-43144Endo is endothermal.
Exo is exothermal.
The low temperature difference is the temperature difference between the melting/freezing onset point and peak point, and high temperature is the difference on the other side of the peak..Tue, 03 Mar 2020 17:58:52 -0600https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?comment=43144#post-id-43144Comment by Fan for <p>I think I have figured out what these mean. If we look at the phase transmission in the following picture(A heat flux-temperature curve, and it could also be viewed as a Cp-Temperature curve), we will get what these inputs mean.
Btw, Enthalpy-temperature curves could be calculated by integrating the Cp-Temperature curve using the following Equations.
<img alt="image description" src="/upfiles/15819733944737864.png"></p>
<p><img alt="image description" src="https://www.researchgate.net/profile/Dawei_Yu/publication/278967001/figure/fig10/AS:614371164160032@1523488908960/Repeated-tests-for-the-determination-of-the-melting-temperature-of-Ag-by-DTA.png"></p>
https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?comment=43145#post-id-43145Sorry for the late replyTue, 03 Mar 2020 17:59:25 -0600https://unmethours.com/question/38447/to-model-pcm-hysteresis-in-energyplus-what-are-the-highlow-temp-difference-of-freezingmelting-curves/?comment=43145#post-id-43145