The word rack is an English term that is used to refer to structures that have very important applications. These structures house related equipment, and are designed to facilitate their assembly and disassembly, with little time and effort. In this sense, a refrigeration rack is a parallel refrigeration system, made up of two or more compressors and other auxiliary equipment.
Rack architecture for refrigeration systems has great advantages in both commercial and industrial applications. For this reason, its use has spread throughout the world, thanks to its great versatility and practicality.
Differences between a refrigeration plant and a refrigeration rack
When you are not familiar with the refrigeration industry, it is possible to confuse these terms. The refrigeration rack is only one part of the refrigeration unit, since the complete refrigeration cycle is carried out in the unit. In other words, only the refrigerant compressors are found in the rack, while the condenser and evaporators make up the entire plant.
What are the parts that make up a refrigeration rack?
Racks for refrigeration systems consist of a rack, compressors, discharge manifold, liquid manifold, and suction manifold. In addition, they have a suction filter, oil separator, line filter, liquid receiver, stop valves, control cabinet, etc. Next, we will talk about the most important parts:
Cooling rack frame
The frame of the refrigeration rack is a stainless steel structure, which provides support for all the components already mentioned above. On the other hand, this structure is closed and organized in the form of cabinets, using metal sheets. Normally, said rack is located in the machine room of each refrigeration plant or in any outdoor part where it is most convenient. Outdoor installation racks come with better weather protection than those designed for indoor spaces.
Parallel refrigeration system compressors
As we mentioned at the beginning of the post, a refrigeration rack is basically a group of compressors that work in parallel. Depending on the type of compressor, there are scroll, screw, and piston compressor racks. In this way, in medium and high-temperature refrigeration cycles, scroll compressor racks are the most used, with powers between 20 and 150 Hp.
On the other hand, screw compressor racks are the most used for industrial uses, with powers between 30 and 1000 Hp. Finally, the racks of piston compressors cover refrigeration powers between 30 and 400 Hp, being the most common among all those mentioned.
Rack discharge manifold for refrigeration systems
The discharge manifold is nothing more than a tube with a much larger diameter than the rest of the pipes in the system. In this way, the collector receives the contribution of refrigerant gas, at high pressure, which comes out of all the compressors in parallel. Normally, each compressor is connected to the discharge manifold by means of a non-return check valve.
The discharge manifold feeds the refrigeration plant condenser with refrigerant gas at high pressure and temperature.
Liquid collector
This is another tube with a large diameter, which receives the refrigerant liquid that returns from the aforementioned condenser. Subsequently, from this liquid collector, the pipes go to the different evaporators, to continue with the refrigeration cycle of the refrigeration system.
Oil separator
This component fulfills the important function of separating the oil from the refrigerant gas that comes out of the compressors. In this way, the separated oil is deposited inside the separator and is then returned to the compressors. Without this separator, all the lubricating oil from the compressors would be lost, contaminating the rest of the refrigeration system.
Suction manifold
The suction manifold is also another tube with a much larger diameter than the refrigeration system pipes. This component is responsible for receiving all the refrigerant gas that returns from the evaporators to then feed the suction of the compressors. In this way, the refrigeration cycle of the system is complete.
Control and power cabinet
All the electrical part of the rack is located in the control and power cabinet. Therefore, the thermomagnetic circuit breakers and the compressor start contactors are located in them. In addition, the cabinet also houses the programmable controller (PLC), which allows automatic control of the entire rack. All electrical signals from the rack temperature, pressure, and flow sensors reach the control cabinet and the PLC.
What advantages do parallel compressor racks offer?
A cooling rack increases the reliability of the cooling system. This aspect is of vital importance in large commercial and industrial refrigeration systems. For example, in the event of a compressor failure, or in preventive maintenance situations, the system continues its operation without major inconveniences. However, this is not possible when there is only one powerful compressor. For this reason, a system of several smaller compressors in parallel is more convenient.
The racks take up less space and are designed to make repairs faster and more convenient. On the other hand, compressors in parallel allow for reaching higher levels of energy efficiency than using a single compressor. This is because the thermal loads are highly variable, and it is more efficient to activate or deactivate compressors automatically.
Are you thinking of placing a compressor rack in your refrigeration system?
If you want to modernize your refrigeration system with a rack, you should seek advice from a company specializing in industrial refrigeration. This company must previously carry out a technical evaluation of its entire system. That is, you must evaluate, among other things, the condenser and the evaporators.
At Intersam we are specialists in the manufacture of condensers and evaporators for showcases, refrigeration rooms, cooling tunnels, etc. Therefore, we can advise you on said equipment, since the efficiency of the refrigeration rack will also depend on this equipment. Contact us and we will give you all the technical advice you need, so that you can get the most out of your parallel refrigeration system, without setbacks.