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![solution
Varying the composition of PCM by incorporating other
materials like embedded aluminum powder into paraffin
wax reduced the charging time by 60%[1] .
Embedding Xgnp [graphite nano particles] up to 7% into
paraffin increased, thermal conductivity from 0.2 to
0.8W/MK](https://image.slidesharecdn.com/pcmsecondppt-181018150238/85/introduction-to-pcm-13-320.jpg)
![continued
Next approach to solve thermal conductivity problem is
to vary the design of storage tank.
So for shell and tube type design is most analyzed.
Its established by various research works the most
suitable configuration is to have heat transfer fluid
within the tube and PCM around it within the shell [2,3]](https://image.slidesharecdn.com/pcmsecondppt-181018150238/85/introduction-to-pcm-14-320.jpg)
![References
[1] A. Sharma et al.: Review on thermal energy storage
with phase change materials and applications.
Renewable and Sustainable Energy Reviews,
vol.13, 2009, pp. 318-345.
[2] S. Kim, L.T. Drzal: High latent heat storage and high
thermal conductive phase change materials
using exfoliated graphite nano platelets. Solar
Energy Materials & Solar Cells, vol. 93,2009,
pp. 136-142.
[3] Thomas Hasenöhrl: An Introduction to Phase Change
Materials as Heat Storage Mediums Project
Report 2009 MVK 160 Heat and Mass Transport
May 09, 2009, Lund, Sweden.](https://image.slidesharecdn.com/pcmsecondppt-181018150238/85/introduction-to-pcm-17-320.jpg)
More Related Content
introduction to pcm
- 1. TOPIC : phasechange material Presented to : Mr. varun dutta Presented by : junaid bhat
- 2. content Introduction Characteristicsof PCM Why PCM Classification Comparison of organic and inorganic PCMs Problems Solution Conclusion References
- 3. INTRODUCTION At presenttwo concepts regarding energy politics are important. First is utilization of renewable energy sources. Second is increased energy efficiency. These concepts serve to make environment green plus divert the focus from fossil fuels
- 4. Continued… Renewable resourcesimplies less pollution Less utilization of fossil fuels implies green environment
- 5. problems Renewable energyis often available at times when there is no need. Example sun shines during day and no energy is available during night, wind energy is the other case. Thus we conclude energy availability is not equal to energy utilization
- 6. solution Energy storage It implies wherever energy is available it can be stored . Conventional energy storing systems being less efficient and less economical, are now been replaced with new energy storing systems involving phase change materials
- 7. PCM Materials thatcan store or release large amount of energy upon melting or freezing. This type of energy storage is known as latent heat storage. Two types of PCM exist Organic and inorganic Organic PCMs include paraffin's wax, fatty acids, alcohols etc Inorganic PCMs include salt hydrates ,alloys , metallic's etc
- 8. Characteristics High heatstorage density Negligible temperature change Very small volume change Latent storage systems store 5-12 times the energy stored by sensible heat storage systems
- 9. Why latent heatstorage? Reason is high storage density.
- 10. Comparison Heat storedor released in sensible storage system is given by dQ = mcΔt Heat stored in latent heat storage system is given by Q = mcΔt +mh Where h=latent heat of fusion
- 11. Organic verses inorganic OrganicPCM low heat of fusion Higher storage density Thermal stability Non corrosive No incongruent melting Lower thermal conductivity Inorganic PCM high heat of fusion Less storage density Less stable Corrosive in nature Incongruent melting Higher thermal conductivity
- 12. Main problems withorganic PCM Lower thermal conductivity The time taken by a PCM to melt or solidify essentially limits the performance of latent heat storage system That is lesser the thermal conductivity ,lesser will be the energy transfer and higher will be time required to store energy
- 13. solution Varying thecomposition of PCM by incorporating other materials like embedded aluminum powder into paraffin wax reduced the charging time by 60%[1] . Embedding Xgnp [graphite nano particles] up to 7% into paraffin increased, thermal conductivity from 0.2 to 0.8W/MK
- 14. continued Next approachto solve thermal conductivity problem is to vary the design of storage tank. So for shell and tube type design is most analyzed. Its established by various research works the most suitable configuration is to have heat transfer fluid within the tube and PCM around it within the shell [2,3]
- 15. continued Figure 1: Shelland tube configuration. The PCM is located in the cylindrical capsules (source: German Aerospace Center (DLR) (http://spie.org/x8476.xml?pf=true- &Article ID=x8476).
- 16. conclusion PCMs have twofavorable properties 1 . They store and release energy at constant temperature 2 . High storage density These two properties make PCM alternative to many heat storage systems
- 17. References [1] A. Sharmaet al.: Review on thermal energy storage with phase change materials and applications. Renewable and Sustainable Energy Reviews, vol.13, 2009, pp. 318-345. [2] S. Kim, L.T. Drzal: High latent heat storage and high thermal conductive phase change materials using exfoliated graphite nano platelets. Solar Energy Materials & Solar Cells, vol. 93,2009, pp. 136-142. [3] Thomas Hasenöhrl: An Introduction to Phase Change Materials as Heat Storage Mediums Project Report 2009 MVK 160 Heat and Mass Transport May 09, 2009, Lund, Sweden.