NH3 Refrigeration: How It Works

NH3 refrigeration or ammonia refrigeration is one of the most affordable methods offering the best results in this area. Believe it or not, ammonia is a natural preservative that provides excellent performance, in addition to serving as a cleaning product. If you want to learn about its advantages, its applications, its operation, and the existing refrigeration systems, continue reading this post.

Some foods such as meat, fish, dairy products, and vegetables have been subjected to this method for two centuries to preserve their quality for a longer time. Throughout this time, NH3 refrigeration has become the most widely used method in the sector, especially due to its thermodynamic properties; that is, it allows changes in the working substance.

On the other hand, the new European regulation on fluorinated gases requires us professionals in the heat exchanger industry to increasingly use natural refrigerants such as ammonia. Furthermore, the growing social awareness of the environment to which we always adapt is another factor to consider in this regard. But what is it, what does it consist of, and what benefits can it generate?

What type of gas is ammonia?

Ammonia is a chemical compound formed by one nitrogen atom (N) and three hydrogen atoms (H) that give rise to the well-known formula NH3. It is a pungent-smelling gas, colorless, that can dissolve in water and in its liquid state is easy to evaporate. Among its main characteristics is the fact that it is a strong base, corrosive, and reacts strongly with acids, oxidants, and halogens.

What is ammonia refrigeration?

NH3 refrigeration consists of the operation of a compressor that reduces the dry gas coming from the separator at evaporation temperature to condensation temperature and carries the discharge gas to the compressor itself. It is in this device where the refrigerant condenses, so that the heat dissipates.

In this way, the liquid refrigerant arrives from the condenser to the expansion device and it is at this point where the ammonia expands to evaporation temperature. From there it passes to the separator where the liquid gas is released from the flash-gas.

Next, the pump draws the liquid refrigerant and sends it to the evaporator, the place where heat exchange occurs. Finally, the process ends when the liquid separates from the gas in the separator and the compressor can draw the dry gas.

Advantages of ammonia as a refrigerant

• This gas is not polluting, making it ideal for complying with the aforementioned European regulation on fluorinated gases. Furthermore, it is perfect for caring for the environment, as it does not destroy the ozone layer nor contribute to the greenhouse effect.
• Compared to other refrigerants, it offers a performance between 3 and 10% higher, which translates into lower energy consumption.
• Continuing with the comparisons, its economic aspect must also be highlighted, as it has a considerably lower cost than other refrigerants and requires less quantity for the same application.
• Thanks to its pronounced odor we can detect if our NH3 refrigeration system has any leak problems.
• It is one of the safest refrigeration methods currently available, given that safety valves are used in pipes and vessels to prevent overpressure, as well as ammonia detectors that prevent unexpected accidents.

Disadvantages of ammonia as a refrigerant

• Ammonia and copper are not compatible, so the chemical compound cannot be used in solutions with tubes made of this material.
• At certain concentrations it is flammable.
• Breathing it in excessive quantities is a gas that is harmful to health, but this should not happen if proper precautions are taken. Our body is capable of tolerating a measured amount of NH3 without any problem.

The systems we use today have all the necessary safety measures, such as safety valves in vessels and pipes to prevent excessively high pressures.

What application does NH3 refrigeration have?

Ammonia can frequently be found in large freezing and refrigeration plants as anhydrous ammonia, which means it has almost no water and its purity is 99%. For comparison, domestic use is made of 10% ammonia mixed with water.

Historically, NH3 absorption refrigeration plants have been used in those industrial sectors that require refrigeration at low temperatures and continuously. Toward the middle of the 19th century, ammonia machines began to be used in the food industry for ice factories and chemical plants.

Since then, this method has gained popularity for cooling and preserving meat, fish, fruit, vegetables, milk, and cheese. In fact, if you stop to think about the products you consume daily that need cold to ensure their durability, it is very likely that at some point in the process they have been stored in a plant that uses ammonia for refrigeration.

Another sector that uses NH3 refrigeration is that of industrial air conditioning equipment and air conditioners, especially in quite large spaces such as airports, hospitals, and hotels.

Inditer is committed to safety and sustainability

Inditer is a leading company in the heat exchanger industry. We always offer our customers products of maximum safety, ensuring energy efficiency and environmental sustainability. This is thanks to the proper use of the Integrated Quality, Environmental, and Occupational Health and Safety Management System.

Do not hesitate to contact us to ask your questions about purchasing your next NH3 refrigeration system. We will be happy to assist you to offer you a personalized solution that best suits your needs. Call 957 664 142 or fill out the form on our website to communicate with you online.