Latent heat
Going back to the process of melting ice is important to note that the amount of energy that should be transferred to 1 kg of ice to melt it is much higher than the energy required to change the temperature of 1 kg of water, say, K. 1 In section 2.4 of the specific heat of water was given as 4.187 kJ/kg K. the energy used to make 1 kg of ice is 335 kJ. The same amount of energy that can melt 1 kg of ice can increase the temperature of 1 kg of water (335 kJ/4.187 kJ/kg K) = 80 K!
When looking at the boiling water, the energy required for evaporation of 1 kg of water 2501 kJ. The same amount of energy that can evaporate 1 kg of water can increase the temperature of 1, but not more than 6 kg of water per 100 K!
These examples show that the energy transfer is connected with the transition between phases significant. So the ice was used for cooling, and it takes a lot of energy to melt the ice, and the ice to melt temperature stays at 0 C.
In the cold-productivity of the refrigeration systems based on the use and control of the phase transition processes of evaporation. As the refrigerant evaporates he absorbs energy (heat) from the environment and placing the item in thermal contact with the boiling of refrigerant may be cooled to low temperature...
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Chillers