Principles of a Refrigeration System: A Complete Guide

Refrigeration is essential to keep the temperature of environments and equipment controlled. Often invisible, a Refrigeration System keeps products fresh, industrial processes running, and environments comfortable. In this blog article, we will look at a Refrigeration System in its different phases, namely:

1. The refrigerant
2. Steps and Components of the Refrigeration Cycle
3. The importance of energy efficiency
4. Compliance with standards
5. System maintenance

The refrigerant

The refrigerant is the protagonist of the Refrigeration Cycle. It is the vehicle by which heat is absorbed from one location and transferred to another. The refrigerant is chosen for its properties. That is, it must allow for an efficient transition between the liquid and gaseous states. The requirements of a refrigerant are:

• thermal capacity;
• boiling point;
• vapour pressure;
• guarantee of safety (it must not be toxic or explosive);
• coefficient of performance.

There are different types of refrigerants, each with specific characteristics. Some contribute to more energy efficiency. Others are chosen because of their environmental properties. In other words, they reduce the global warming potential (GWP). In a recent article, we explore this point. The choice of the refrigerant is an important and strategic decision. First, it influences the efficiency of the operation. Second, it ensures that environmental regulations are being complied with. Finally, it ensures the security of the system. That’s why we open this article with this point: choosing the right refrigerant.

The importance of energy efficiency

It is not in vain that the term “energy efficiency” comes up so often when we approach the topic of refrigeration. The truth is that this concept works as an operational metric. It is the way to read whether a system saves resources and contributes to reducing the impact on the environment. Complying with this metric implies keeping up with advances in technology. For example, variable frequency drives allow you to adjust the power of the compressor as needed. Another case is the line-start permanent-magnet (LSPM) motor technology. It takes advantage of the high motor efficiency and low heat input into the refrigerant, estimating 14% annual savings when compared with standard compressors. In addition to energy, there are practical decisions that influence this metric. Proper choice of components and their cleaning, regular maintenance, and monitoring are essential steps.

Steps and Components of the Refrigeration Cycle

Behind the scenes of a Refrigeration System, we can see different processes that take place simultaneously. This translates into the so-called “Refrigeration Cycle”. In this, the refrigerants are transformed to be able to extract heat from the environment and produce cold. This cycle comprises four stages: compression, condensation, expansion, and evaporation. Everything happens in a controlled way to keep the temperatures of a given environment under control. In the article “Demystifying CO2 Refrigeration System”, we explain how each step takes place and the function of each component.

Compliance with standards

This point is essential to ensure safe, productive, and environmentally responsible operations. Several standards define rules in the use of Refrigeration Systems. EN 378, ISO 5149, ISO 817, or the F-Gas Regulation, in another way, are some examples. On 17 January, the European Parliament approved a new rule related to the use of F-Gas. More specifically, the focus will be to phase out the use of HFCs in the EU by 2050 and reduce the EU’s share of these gases between 2024 and 2049. These standards include safe installation requirements, refrigerant handling requirements, and more. This scenario will continue to undergo updates and adaptations. That’s why it’s important to highlight it as a topic to follow. For example, there may be new bans or restrictions on certain refrigerants. As well as incentives for more efficient technologies.

System maintenance

It is important to understand a Refrigeration System in its different phases, including after installation. Maintenance is essential to ensure that the system maintains efficiency. There are 3 aspects to consider: preventive maintenance, diagnosing common problems, and replacing worn components. Here are some of the practical actions to consider:

• regularly check key components;
• change refrigerants according to the manufacturer’s specifications;
• cleaning of condensers and evaporators;
• attention to common problems such as leaks or compressor problems;
• monitor belts and filters.

In the end, we realized that decisions about refrigerants until the evaluation of the system’s performance, are important to ensure good performance and minimize impacts on the environment. As technology advances, challenges and opportunities arise. After this opening, the next step is to know in detail the technical characteristics of a Refrigeration System. In our academy, we offer specific training to learn how to operate CO2 Refrigeration Systems in different configurations.