“How do can we apply the laws of physics and chemistry to make a refrigerator?”
Refrigerators allow us to survive in the modern world, whether it be in keeping our buildings cool or our food fresh. However, how exactly do these systems work? Well, let’s look at one such approach.
First, let’s start with a solution of hydrogen and ammonia in a boiler. Then, let’s apply heat to separate out these two substances, leading the ammonia gas to a higher pipe and the hydrogen to a lower pipe to be mixed later. Once this is complete, let’s send the ammonia gas through a heat exchanger to condense it into a liquid. Afterwards, let’s shove this new liquid with the hydrogen gas in a freezer (evaporator). The highly reactive chemical reaction will absorb a large amount of heat from the surroundings. The ammonia gas will then be evaporated with a second heat exchanger and sent back to the original boiler, starting the process all over again!
Absorption Refrigeration is commonly implemented in food storage in commercial vehicles and in buildings for waste heat recovery.