Building a Thermal Energy Storage System: What Additive Can I Use?

[alexwin_75]

im working on building a simple thermal energy storage system...im using water as phase change material.The PCM will be injected into spherical capsules and dropped into a storage tank.Now my problem is that the freezing process initiates only at arnd -12 C.Remember it is under pressure..
Though I am not filling the capsule completely.I need to add some quantity of additives to raise the freezing point of water and get it back to 0 c...
Silver Iodide i cannot use since the solution cannot be properly injected into
my spherical capsules...any ideas?
what additive should i add ?

 

[Greg Bernhardt]

Have you considered using glycol-based additives? Glycols are often used as antifreeze, and they can be injected into spherical capsules. They work by lowering the freezing point of the water and making it easier to store in a liquid state. You can also look into calcium chloride or magnesium chloride. These are both salts that can be used to raise the freezing point of water.