Is ammonia refrigeration better, or are chillers better?

Reply: 1. The poster’s view may have some issues; in my understanding, it should be a comparison between absorption refrigeration using ammonia (lithium bromide) and ice machine refrigeration. 2. Ice machine refrigeration, also known as cryogenic refrigeration, is widely used in the ammonia synthesis industry. It is generally driven by electric motors. Initially, piston-type refrigerators were the most common design, but since the 1980s, screw-type refrigerators have been used in new projects. In China, Dalian Cold, Wuhan Cold, and Yantai are the three major manufacturers. 3. Since ice machine refrigeration consumes electricity, amid the broader trend of energy conservation and emission reduction, ammonia absorption refrigeration has been widely promoted. Absorption refrigeration uses a binary solution composed of two substances as the working fluid. These two substances have different boiling points at the same pressure; the component with the higher boiling point is called the absorbent, while the component with the lower boiling point is called the refrigerant. There are two common combinations of absorbents and refrigerants: one is lithium bromide-water, that is, lithium bromide absorption refrigeration ； Another is water-ammonia, that is, ammonia absorption refrigeration. Ammonia absorption refrigeration is mainly used in facilities where there is a large amount of waste heat that is not fully utilized by the enterprise. Waste heat is the energy in a system that is not utilized under certain production process conditions; in other words, it is excess or unused energy. It includes the waste heat from high-temperature exhaust gases, the waste heat from cooling media, the waste heat from exhaust gases and wastewater, the waste heat from high-temperature products and slag, the waste heat from chemical reactions, the waste heat from combustible exhaust gases, liquids, and waste materials, as well as the excess pressure of high-pressure fluids.

An ice machine uses liquid ammonia for cooling; it operates on a principle similar to that of a refrigerator, just on a larger scale

If it’s for a larger scale, of course, an ice-cooling system is the better choice. The principle of ammonia-based refrigeration still requires cooling capacity; ammonia is merely an intermediate substance, acting like a refrigerant in systems such as York units. So these two comparisons are also meaningless.

Agree with the view on the second floor. Both ammonia absorption refrigeration and ammonia ice mechanism refrigeration actually utilize the endothermic effect of ammonia vaporization. The difference between the two is that chillers can be used for cooling in low-temperature conditions (ammonia can evaporate under negative pressure), while absorption refrigeration is generally used in situations where there is an abundance of low-pressure steam available.