CO2 challenges ammonia as an option in industrial refrigeration.
Traditionally, ammonia (NH3 or R717) is the typical choice for large-scale refrigeration systems. It has great thermodynamic properties and no global warming potential (GWP). However, advancements in CO2 (R744) refrigeration technology make it a suitable option for some of these applications on the lower end of the capacity range.
R744 systems have been primarily made for commercial refrigeration, but they can also be used in larger systems, as reported by Accelerate America, in an article about Henningsen Cold Storage’s pioneering use of transcritical CO2 in industrial refrigeration. (Accelerate Americais published by shecco, the publisher of this website.)
R744 can effectively be used in two formats for industrial applications: cascade systems and transcritical systems. It is the fastest growing refrigerant in this market, according to markets and markets.
“CO2 is moving quickly in the market.” — Pete Lepschat, Henningsen Cold Storage
A cascade system uses ammonia as a primary refrigerant, which cools the secondary refrigerant CO2. Danish component supplier Danfoss observed that this option can be used in applications where a smaller ammonia charge is needed. The company praises this system’s efficiency, especially in low temperature applications, adding that R744 is excellent as a brine.
“In places where it is only allowed to use a limited amount of ammonia, cascade or secondary CO2 systems are a great solution.” — Danfoss
Transcritical CO2 is another option for industrial refrigeration that’s gaining attention. In 2018, a new storage facility in Hamburg, Germany, runs entirely on it. The natural refrigerant provides the facility with 2 mW of cooling power. It has a significantly lower global warming potential (one) than HFCs and is non-toxic and non-flammable. Thus, it is not subjected to regulatory burdens. It also has great thermodynamic properties. Due to this, companies such as Carnot Refrigeration report growing demand for R744 in industrial applications.
“The more I work with CO2 [in the industrial sector], the more I see opportunities.” — Marc-André Lesmerises, Founder and CEO, Carnot Refrigeration
R744 and R717 are both safe and efficient refrigerants, if used correctly. However, one can be preferable over the other in certain settings. For example, U.S.-based Henningsen Cold Storage, selected transcritical CO2 for two of its plants.
R744’s growth can currently be observed in smaller industrial applications. But if the current development continues, larger compressors for more cooling power will enable its use in bigger applications.
To find out more about CO2 in industrial applications, read the articles below:
Taking on Transcritical in Cold Storage
By shecco , published Oct 08, 2018 - 2 pages