Industrial refrigeration systems are critical infrastructure for facilities across food & beverage, biotech, aerospace, and energy sectors. Vapor compression refrigeration systems provide reliable temperature control for product preservation, process cooling, and environmental conditioning in large-scale operations. Understanding how these systems work helps facility managers and engineers make informed decisions about refrigeration solutions that meet their operational requirements.
In this guide, we will explore how a compression refrigeration system works, examine different refrigeration compressor types, and review the four main components that create the refrigeration cycle.
The vapor compression refrigeration system operates by circulating liquid refrigerant through four stages of a closed system. As the refrigerant circulates, it alternately compresses and expands, changing state from liquid to vapor. During these state changes, the system absorbs and expels heat, effectively lowering the temperature of the conditioned space.
In the first stage of the refrigeration cycle, refrigerant enters a compressor as a low-pressure vapor. The compressor compresses the refrigerant to a high-pressure vapor, causing it to become superheated. Once compressed and heated, the refrigerant leaves the compressor and enters the condensation stage.
Different refrigeration compressor types serve various industrial applications, each offering specific advantages for different operational requirements:
Reciprocating Compressors:
Scroll Compressors:
Screw Compressors:
Centrifugal Compressors:
The choice between refrigeration compressor types depends on facility size, load requirements, operating hours, and efficiency priorities.
After leaving the compressor, the hot vapor refrigerant enters the condensation stage. The refrigerant flows through a condenser with S-shaped tubes while cool air is blown across the tubes by a fan.
Heat transfers from the tubing to the cooler air because the air temperature is lower than the refrigerant temperature. This heat transfer causes the hot vapor refrigerant to reach its saturated temperature, changing state to a high-pressure liquid. Once in high-pressure liquid state, the refrigerant moves to the metering and expansion stage.
The high-pressure liquid refrigerant enters a metering device or expansion valve. The metering device maintains high pressure on the inlet side while expanding the liquid refrigerant and lowering pressure on the outlet side. During expansion, the liquid refrigerant temperature also reduces.
In a cool, low-pressure liquid state, the refrigerant enters the evaporation stage, where heat removal from the conditioned space occurs.
The cool liquid refrigerant leaves the metering device and enters coiled tubes in an evaporator. Fans blow warm air from the conditioned space across the evaporator coils. The cooler refrigerant in the evaporator coils absorbs heat from the warmer air, reducing the conditioned space temperature.
As the refrigerant absorbs heat, it boils and changes to a low-pressure vapor. The low-pressure vapor returns to the compressor, and the cycle repeats.
When evaluating vapor compression refrigeration systems for industrial applications, several factors influence system design and performance:
Capacity Requirements: Large facilities require systems capable of handling significant cooling loads while maintaining consistent temperatures across multiple zones.
Energy Efficiency: Industrial refrigeration systems operate continuously, making energy efficiency crucial for operational costs. For industrial applications you’ll also want to consider an energy management system like Airixa to help monitor and optimize energy usage over time.
Reliability and Maintenance: Industrial operations cannot afford extended downtime. System design should prioritize reliable components and accessible maintenance points.
Integration Capabilities: Modern industrial refrigeration systems often integrate with facility automation systems for monitoring, control, and optimization.
Understanding how vapor compression refrigeration systems work helps facility managers make informed decisions about industrial refrigeration solutions. The choice of refrigeration compressor types, system sizing, and integration requirements varies based on specific operational needs in food & beverage, biotech, aerospace, and energy facilities.
Leling Product Page
Ready to explore how refrigeration control systems can optimize your facility operations? Connect with our refrigeration controls specialist to learn how Process Solutions can help design and integrate reliable cooling solutions for your industrial application.
Refrigeration compressor as one of the most basic components of refrigeration, covers a major part of its construction cost. Optimal and correct selection, along with ensuring the authenticity of the compressor purchased, can guarantee the most optimal cost at the time of purchase, as well as reducing future maintenance costs.
What is a refrigeration engine?
The refrigeration compressor, commonly referred to as the refrigeration engine, is the heart of a refrigeration refrigeration system. The refrigeration engine can be categorized from different perspectives. These motors may be classified according to their application and temperature range (below zero, above zero). It may be based on the refrigerant used in them (gas R22, R404A, R134a or…) or their operating mechanism (piston, scroll, screw…) or the area where the refrigerator is to be installed. Accept. The most important distinguishing feature of a refrigeration engine is its power or power consumption, refrigeration power or displacement flow. In the some cooling industry, compressors are usually classified based on horsepower. However, this statement may not be scientifically accurate. In this article, all the above angles are discussed. In addition, we get acquainted with the types of engine brands, how to choose them, the price of the refrigeration engine, installation and maintenance conditions, and much more.
Types of refrigeration compressors based on operating mechanism
In terms of operating mechanism, compressors generally fall into the following categories:
Reciprocating Compressor، Rotary Compressor، Piston Compressor، Screw Compressor، Scroll Compressor
Piston compressors come in two types, hermetic or closed (non-repairable) and toxic, hermetic or semi-closed (repairable). These compressors may be single-cylinder or multi-cylinder. These compressors have a wide range of power from one to 70 horsepower. Screw compressors used in refrigeration systems are also mainly toxic hermetic screw types that are mostly used in refrigeration rack systems. These compressors generate more pressure than other compressors in exchange for lower power consumption. Screw compressors are available in capacities up to 35 hp. Scroll compressors used in refrigeration systems usually have low noise and have a power range of 1.5 to 30 hp. All the above models are compatible with different refrigerants depending on the type of oil used in the compressor.
Types of refrigeration compressors based on the manufacturer
Reputable brands that produce refrigeration compressors around the world include Carrier, Bitzer, Danfoss, Copeland, Frascold, Bock, Dorin and Refcomp. Each of these brands have offered different models to the market according to temperature range, type of refrigerant gas, power consumption, etc. In the following, we will deal with the most important types of models of these brands in the field of cold storage.
Bitzer refrigerator compressor types based on temperature range
Refrigerator compressors are generally divided into three categories: above zero, below zero and deep freeze, depending on the type of use used and the products to be stored. Above zero refrigeration temperature range is usually designed and used for storage conditions of 0 to 4 degrees Celsius, sub-zero refrigeration for storage conditions of -18 and cold storage with deep freeze temperature range for -40 degrees Celsius.
Refrigeration compressor price
The price of a refrigeration compressor depends directly on its capacity. Also, whether it can be repaired or not has a significant effect on the price of the refrigeration compressor. At equal power, the price of the R22 gas-compatible refrigeration compressor is slightly cheaper than the 404, 134, 407 and gas refrigeration compressors. Another factor influencing the price of a refrigeration engine is the brand of the engine manufacturer. The price of refrigeration engines made in European and American countries is slightly more expensive than refrigeration engines made in China, Thailand and Taiwan.
Another parameter affecting the price of the compressor is its application. Refrigeration compressor with application below zero in the temperature range up to -45 has more special features than the refrigeration engine above zero and as a result has a higher price in equal power.
Buying a refrigeration compressor
The most important thing about buying any product is to make sure it is authentic. Buying a refrigeration compressor is no exception and requires authentication. Each refrigeration compressor is functionally tested by its manufacturer at the time of production and the results are provided by the manufacturer along with the test date. A special number (serial number) is engraved on each refrigeration compressor and the authenticity of the product is usually obtained through this code. Some compressor manufacturers, such as the German Bitzer, have special methods for identifying the compressor. For more information, refer to the identification of the Bitzer compressor.
Select a refrigeration compressor
Several basic parameters are required to select the optimal refrigeration compressor. The most important of these parameters are the temperature of the evaporator and condenser and the required refrigeration capacity (usually expressed in kilowatts). With these parameters in hand, you can refer to the catalog of the compressor manufacturer. Usually, the refrigeration compressor is selected by the software of the compressor manufacturer. For example, Bitzer Company has considered two routes of the company’s website at www.bitzer.de, as well as its Bitzer compressor selection software for compressor selection. Danfoss Company, through its software called Cole Selector selection software, has put the compressor selection path in front of its customers. Also, other manufacturers such as Book, Fraskeld, Refcomp and Dorin have each developed their own compressor selection software.
Calculate the power of the refrigeration compressor
Refrigeration compressor power is usually expressed in horsepower. This number indicates the power consumption of the compressor. This method is not scientifically accurate. The best way to calculate compressor power is to identify the refrigeration capacity from the manufacturer’s catalog based on the evaporator and condenser temperatures.
Installation
The operation of each refrigeration compressor consists of two parts, mechanical and electrical. The mechanical part of the refrigeration compressor includes connecting the suction and discharge parts to the refrigeration piping system and ensuring that the appropriate control components are considered to prevent damage to the compressor. The electrical part of starting the refrigeration compressor also includes the correct way of wiring the compressor for three-phase compressors (star or triangle) or using the appropriate starter kit (capacitor) to start the compressor.
Refrigeration engine equivalence
Comparing refrigeration engines between different models and brands is one of the issues that can always occur. Lack of spare parts, dissatisfaction with engine performance, price and… are the most important reasons for moving to change the model and brand of refrigeration engine. To do this, all the technical considerations required for this work must be taken into account. One of the most important parameters for the correct equation of the refrigeration engine is to pay attention to the amount of displacement (Displacement) and the refrigeration capacity produced by the engine at equal temperature conditions.
Refrigeration compressor repair
As mentioned above, refrigeration compressors made by different brands are designed and marketed in repairable or non-repairable types. Refrigeration compressor repair should be done by a reputable repair shop so that the cost of repairing the compressor leads to the desired performance of the compressor for a suitable period of time. The most important parts used in the refrigeration compressor that may need to be replaced during repair are the compressor crankshaft, compressor connecting rod, compressor thermistor, compressor valve, compressor bearing and compressor washer.
Refrigeration compressor oil
The refrigeration compressor, like other compressors in the ventilation and refrigeration industry, is charged with different oils by its manufacturer. The type of refrigeration compressor oil used in refrigeration compressors is mainly a function of the type of use and temperature range of using the refrigeration engine. Generally, refrigeration compressor oil is divided into two popular categories: mineral and POE or polyolester. In addition, there are Alkylbenzene and PVE or Polyvinylester compressors, which are used in more specific compressors. Each of these categories includes different models according to parameters such as Viscosity of compressor oil, Density of compressor oil, Flash point of compressor oil, Pour point of Pour compressor oil.
R22 gas is mainly compatible with mineral oils and other refrigerants such as R134a, R404A, R407C and R410A with non-mineral oils such as polyolester oil (POE). Using high quality original oil has a great effect on increasing the life of a refrigeration compressor and one of the most important reasons for the failure of the refrigeration engine is the presence of contamination and moisture in the refrigeration compressor oil.
The most common causes of refrigeration compressor failure
The most common causes of refrigeration compressor failure that can have costly consequences are:
Compressor operation at high pressure Refrigerant gas shortage in refrigeration cycle Unconventional power consumption No moisture in refrigeration cycle Unsuitable refrigerant oil and gas charge
Due to the high price of refrigeration compressors and the need to repair it in the years used, one of the most important characteristics of evaluating a compressor is the presence of spare parts and compressor parts in the market. The more these parts are in repair shops, the more the tendency to use that brand increases. Ensuring the authenticity of compressor parts and spare parts is one of the most important issues considered by customers in this industry. For this purpose, many companies importing refrigeration compressors also supply refrigeration compressor parts to ease the minds of their customers about the authenticity of these parts.
The company is the world’s best refrigeration compressor manufacturers supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.