The back of each refrigerator is marked with the freezing capacity in kilograms, indicating how many kilograms of beef can be frozen from 25℃ to-18℃ in 12 hours. If there is less milk to be frozen, for example, only 250mL, it is estimated that 2 hours will be enough.
Freezing refers to lowering the temperature to freeze the object. Also known as "refrigeration", it is a method to artificially create low temperature by applying the principle of thermodynamics. Refrigerators and air conditioners are based on the principle of refrigeration. From a chemical point of view, a gas with a high critical point is generally liquefied under pressure, and then vaporized to absorb heat, and this process is repeated. When liquefied, it releases heat in other places, and when vaporized, it absorbs heat within the required range.