Ammonia refrigeration is a type of refrigeration system that uses ammonia as the refrigerant. Ammonia is a colorless gas with a very pungent odor that is commonly used in industrial refrigeration applications due to its favorable thermodynamic properties.

In an ammonia refrigeration system, ammonia is compressed to a high pressure and then condensed into a liquid. The liquid ammonia then flows through an expansion valve, which reduces its pressure and causes it to evaporate into a gas. As the ammonia evaporates, it absorbs heat from its surroundings, which cools the area being refrigerated.

Ammonia refrigeration systems are widely used in a variety of industrial applications, including food processing, cold storage warehouses, and chemical processing plants. They are often preferred over other refrigerants because they have a high refrigeration capacity, are energy-efficient, and have a low environmental impact.

However, ammonia can be hazardous if not handled properly, as it is toxic and flammable. Therefore, strict safety measures must be taken when designing, installing, and operating ammonia refrigeration systems. These measures typically include using proper ventilation, implementing emergency shutdown systems, and providing adequate training to personnel who work with the systems.