Phase Changing Material Introduction with Medical application
- 1. PHASE CHANGE MATERIALS (PCM) R.SARATHKUMAR 2016251038 M.E. R and AC RA7212 SEMINAR 1
- 2. • Introduction • What is a PCM • PCM physical principle and behavior • Water as a PCM • PCM classification • PCM general applications • PCM application in medical field • Birth asphyxia (detailed study) • Conclusion 2
- 3. • The demand for comfort cooling is expanding much. • Thermal energy storage is renewable source of energy to develop cooling system. • Minimize ozone depletion and global warming. Cold thermal storage systems imbalance between production and demand. INTRODUCTION 3
- 4. A phase-change material (PCM) is a substance presenting a high heat of fusion, and capable of storing and releasing large amounts of energy. Heat energy is absorbed or released when the material changes from solid to liquid phase and vice versa, thus, being classified as latent heat storage (LHS) units. 4
- 5. HOW IS PCM MANUFACTURED? PCMs are manufactured by mixing various chemicals in particular proportions under appropriate environment conditions. 5 WHAT ARE THE MATERIAL PROPERTIES? Material Latent Heat, Density, Specific Heat in liquid and solid state, thermal conductivity in liquid and solid state, toxicity, flammability, operating temperature range and maximum operating temperature would be the specifications.
- 6. 6 HOW DO YOU MANIPULATE THE PHASE CHANGE TEMPERATURE? By adding different chemicals or altering the proportions of it IS THE PCM TOXIC OR CORROSIVE? (TO STEEL?) savEnrg PCM use non toxic base materials - some inorganic PCMs may be corrosive to some metals WHAT IS THE PCM MADE OUT OF? PCMs are made from either inorganic chemicals or organic chemicals
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- 8. The Latent Heat of fusion is the amount of thermal energy required to cause a liquid to freeze into solid 8
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- 10. • Latent Heat • Sensible Heat 10
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- 12. Heat (energy) is transferre d into the ice. The heat is used to break the bonds between molecules, not to increase the average kinetic energy of the molecules. Since the bonds among the ice molecules have been broken, water is formed. The water molecules, at this moment, have the same average kinetic energy as they did when they were ice. Since the ice and water molecules both have the same average kinetic energy, they are at the same Kelvin temperature. • Changing levels 12
- 13. 13 Source Research Gate PCMs can be categorized on the basis of latent heat of fusion and melting temperature
- 14. 14 ORGANIC MATERIALS melt and freeze frequently without phase separation that help to retain their latent heat of fusion. Paraffin Non-paraffin mostly straight chain n-alkanes and with the increase in chain length of paraffin wax, melting point and latent heat of fusion increase Non-paraffin have the advantage of higher heat of fusion but comes at the expense of higher cost
- 15. 15 • Inorganic PCMs, on the other hand, store about twice as much energy per volume as organic PCMs, use cheaper raw materials, tolerate impurities, and are flame-retardant. http://www.coolcomposites.com Inorganic PCMs • Inorganic PCMs are salt hydrates. The advantages of these materials are: high latent heat values, non- flammable, low-cost and readily available
- 16. 16 • These are combination of two or more components and shows minimum melting temperature. Eutectic almost melts and freezes without phase separation • Eutectics tend to be solutions of salts in water that have a phase change temperature below 0°C (32°F). Eutectics
- 17. B. Zalba et al. / Applied Thermal Engineering 2 (2003) 251–283 Inorganic PCMs 17
- 18. Organic PCMs B. Zalba et al. / Applied Thermal Engineering 2 (2003) 251–283 18
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- 21. Study about PCM application in Medical Field Birth Asphyxia Or Neonatal Asphyxia Or Perinatal Asphyxia 21
- 22. Asphyxia means LACK OF OXYGEN. Birth asphyxia happens when a baby's brain and other organs do not get enough oxygen before, during or right after birth. Without oxygen, cells cannot work properly. Waste products (acids) build up in the cells and cause temporary or permanent damage Some causes of birth asphyxia may include: •Too little oxygen in the mother's blood before or during birth •Problems with the placenta separating from the uterus too soon •Very long or difficult delivery What Is Birth Asphyxia? This causes hypoxic-ischemic encephalopathy 22
- 23. What is hypoxic-ischemic encephalopathy? asphyxia is a leading cause of death or severe impairment among infants. Source Michigan Cerebral Palsy Attorneys 23
- 24. THE IMPACT OF ASPHYXIA 2/3 of infant mortality in India Second largest cause of death among infants in first month WHO says 683,000 babies died in 2012 Source ; ISHRAE JOURNAL -JULY AUGUST 2015 4times of Chepauk Stadium seating is 150000 24
- 25. • Research shows that cooling the baby's internal body temperature to 33.5 degrees C (about 91 degrees F) for up to 72 hours can help protect the baby's brain from damage during the second stage of asphyxia. • Normal blood flow and oxygen are restored to the brain. • The baby must be at least 36 weeks' gestation (not more than four weeks early) to qualify for this treatment. • Using ice packs to cool the baby (sadly a failure one ) Only treatment is Hypothermia Source from www.seattlechildrens.org 25
- 26. The Problem in conventional • Very expensive 15-20lakh • Require very high manual supervision • Possibility for Tissue damage (fat necrosis) • Uninterrupted power needed to run 26
- 27. PCM based Neonatal cooling device For precise temperature control cascaded system of PCMs is used. ’Quasi-automated’ cooling system is created Source MiraCradle™ - Neonate Cooler 27
- 28. • Passive heating and cooling substances , usually made of a salt hydride , fatty acid and ester or paraffin such as Octadene • PCMs are solid at room temperature , but when in contact with warmer objects they liquefy and absorb and store heat • Liquid PCMs can solidify and give off heat • Once its is stored in refrigerator for 6 to 8 hours it can been used up to for 72hours without uninterrupted power August 2, 2015 28
- 29. • Plastic structure-framework for placing all the other components • provides insulation to the PCM Insulated Cradle savE®FS-29 • In solid state passively extracts heat from the neonate’s body which is at 37°C • Inducing and sustaining hypothermia. savE®FS-21 Bottom Layer Middle Layer • It is used in conjunction with savE®FS - 29 to quickly bring the temperature of the neonate down to 33°C. Conduction Mattress • It is a gel bed which provides a smooth surface for the baby to lie on • Improves heat transfer between the baby and the PCM 29
- 30. A NEONATAL COOLING DEVICE IN USE Source MiraCradle™ - Neonate Cooler 30
- 31. Advantages • Cost is 1/10th of existing equipment • All PCMs are reusable so no maintenance cost • Does not require electricity when in use • No intimidating wires and circuits for nurses and doctors 31
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