×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# Request for Sample Calculation &Assistance with Phase Change Material System Design for Cold Sto

## Request for Sample Calculation &Assistance with Phase Change Material System Design for Cold Sto

(OP)
Dear Engineering Forum Members,

I am currently working with a cold storage facility on implementing a Phase Change Material (PCM) system. As I am relatively new to this technology, I am seeking your valuable insights and guidance.

Project Details:
The project involves integrating a PCM system into an existing cold storage facility.
I have reviewed the forum's search function but haven't found specific sample PCM calculations.

Request for Assistance:
I would greatly appreciate assistance with the following aspects of PCM system design:
Calculation Methods: Could you please share or guide me towards resources that detail the calculation of critical parameters like:
Required PCM mass
PCM cooling capacity
PCM discharge time and cycles
Re-freeze time
Electricity consumption for PCM freezing

Provided Material Properties:
For reference, I have included the provided specifications of the chosen PCM:
Ambient temperature (Ta) = 32°C
Chilled storage temperature (Tc) ≈ 2°C
Wall U-value: 0.425 W/m²K
Latent heat of fusion (solid/liquid) (Lh_s/Lh_l): 213 kJ/kg / 271 kJ/kg
Specific heat (solid/liquid) (Cp_s/Cp_l): 3.86 kJ/kg.K / 5.96 kJ/kg.K
Melting temperature (Tm): 6°C
Freezing temperature (Ts): 5°C
Density (solid/liquid) (ρ_s/ρ_l): 727 kg/m³ / 763 kg/m³
Thermal conductivity (solid/liquid) (k_s/k_l): 0.13 W/mK / 0.12 W/mK

Missing Information and Assumptions:
I understand that some additional information is crucial for accurate calculations. Please feel free to suggest reasonable assumptions for the following missing parameters:
Wall areas
Room volume
Mass of stored goods and products
Heat gain rate

High Energy Savings and Additional Considerations:
In my initial calculations, the PCM system showed a significant reduction in daily electricity consumption compared to a traditional refrigeration system (around 90%). This result seems overly optimistic. Could you offer insights into this discrepancy and potential reasons for a more realistic energy saving range?

Furthermore, could you advise on any additional infrastructure required for a smooth-functioning PCM system besides the PCM enclosures themselves?

Thank you in advance for your time and expertise. I eagerly await your valuable feedback and suggestions.
Replies continue below

### RE: Request for Sample Calculation &Assistance with Phase Change Material System Design for Cold Sto

Talk to manufacturer of that PCM about design guidelines. I assume it isn't just ice-storage but some other material. I suspect a lot of what applies to ice storage will apply here.

You need to know if the PCM should provide all day cooling and re-charges over night. Or if you still run a smaller chiller during the day etc. How many hours a night do you have to re-freeze? The answer may depend on the electric utility charges.

You need to know what fluid temperatures you need for the cooling coils used in that facility.

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!