The compressor is one of the crucial parts of a cooling system. While the other components are also important, its role is to compress gas and provide the required mechanical energy. Since the early twentieth century, it has gone through different stages of development in order to suit different applications on the market and today, there are several common types that are widely applied.
As a renowned distributor of Emerson refrigeration parts, Gustave A. Larson, says that correctly matching a type with the specific needs of the system ensures optimal performance. Have a look at these common models and their characteristics.
What are the common types of refrigeration compressors?
Apart from enhanced efficiency, the right compressor will also ensure a prolonged service life. These 3 models have a wide range of application:
Reciprocating / piston compressors
This model is the simplest, but also the most common one. It is available in all sizes and configuration types and it’s quite affordable. However, it does require continuous lubrication and any liquid intrusion at the inlet may result in rapid deterioration of the valves.
It consists of a crankshaft which drives the pistons so they can deliver gasses of high pressure. Consequently, these parts, along with the motor, should be the focus of regular maintenance.
The screw compressor has a powerful output which can range from 20kW to as much as 1,200kW. However, it tends to be noisy and it takes up more space than a reciprocating compressor, so it’s necessary to place it accordingly.
It functions in a way that one or two screws rotate at high speed and compress the gas which goes in and out of the unit not through valves, but through ports. This system also requires constant lubrication and cooling.
This is one of the most sophisticated models and it uses radial movement which consequently reduces mechanical stress. It’s tolerant to a certain amount of liquid since it automatically vaporizes it, and due to the centrifugal forces, the risk of gas pocket leakage is significantly reduced.
With fewer parts, there’s less room for faults and it’s easier for maintenance. The power output ranges from 40kW to 50kW, but you can combine more units in parallel.
What are the system architectures of compressors?
In addition to the available types, there are also three system architectures which offer different ease of access when it comes to service. These are the 3 options to choose from:
With the open system, the compressor and motor are separated, which allows the use of gas, electric, or diesel motors. When it comes to service, there’s easy access to all parts which allows for efficient repairs. In addition, this design offers high power output.
As the name suggests, in this system, the compressor and motor are both encased in an envelope that is hermetically welded. While this kind of sealing protects the essential components from the environment, it doesn’t allow the option of opening for service or repairs. If it stops working you’ll need to replace it.
This kind of architecture combines the benefits of hermetic and open compressors. While it does enclose the motor and compressor in a hermetically welded envelope, you can open it for repairs. What’s more, you can also integrate a liquid cooling system into the casing to ensure proper thermal control.
When choosing the right option for your cooling system, you’ll need to decide which of the available best fits your needs. The proper selection will depend on the load, operating environment, the available space, and other factors.