Modern food cooling systems go far beyond the usual household appliances that we see in the kitchen. In the industrial sector, supermarkets and specialized warehouses, a concept is often used where the generation of cold is separated from the storage location. Remote cold is just such an engineering system that allows you to service huge volumes of chambers with one powerful unit located outside the premises.
Understanding how it works refrigeration center, is necessary not only for engineers, but also for business owners planning to open a retail outlet. This is a complex combination of compressors, condensers and evaporators connected by kilometers of pipelines. Unlike household monoblocks, here the refrigerant circulates in a closed circuit connecting remote objects.
The effectiveness of such a scheme is due to the possibility of centralized temperature control. The store owner can regulate the microclimate in dozens of storefronts at the same time, without entering each of them. This fundamentally changes the approach to logistics and safety of perishable goods.
Conceptual differences from household analogues
The main difference between an industrial system with remote refrigeration is scalability. If an ordinary home refrigerator contains all components in one housing, then here compressor-condensing unit (KKB) is taken outside or to a separate technical room. This allows you to get rid of noise and heat radiation inside the sales area.
The second important aspect is the use of several compressors in one bundle. This configuration is called refrigeration machine or aggregate. It works on the cascade principle: when the load increases, the second or third compressor is turned on, which ensures high energy efficiency. Household analogs cannot do this, working in the start-stop mode of one motor.
⚠️ Attention: Designing an external cold system requires accurate thermal engineering calculations. An error in selecting the power of the KKB will lead either to damage to the products or to constant downtime of the equipment in standby mode.
The third factor is the type of refrigerant and pressure in the system. Industrial installations often operate on ammonia or high-pressure freons, which requires compliance with the strictest safety standards. Pipeline routes are laid taking into account differences in heights and lengths, which is impossible in compact household appliances.
Architecture of a remote refrigeration system
Any system remote cooling is based on three main elements: a cold source, a consumer and a connecting line. The source is a compressor-condensing machine, which compresses the gaseous refrigerant, turning it into a liquid with the release of heat. This heat is removed through air or water condensers.
The consumer is refrigerated display cases, lari, blast freezing chambers or storage rooms. Air coolers (evaporators) are installed inside them, where liquid freon boils, taking heat from the air in the room. Air circulation is ensured by powerful fans that create a uniform temperature background.
- ❄️ The compressor unit is the heart of the system, creating pressure.
- 🌡️ Evaporating units are units that directly cool the air.
- 🔗 Refrigerant route - copper or steel pipes connecting the unit and display cases.
- 🎛️ Automation system - controllers that control temperature and protection.
The connecting line is a complex engineering network. It includes not only liquid and gas supply pipes, but also an oil line, a hot gaseous phase line, and a drain for condensate removal. To ensure oil return to the compressor, oil lifting loops separators are used.
Why do you need a receiver in the system?
The receiver serves as a buffer tank for liquid refrigerant. It allows you to accumulate freon at low loads (for example, at night) and quickly release it during a sharp temperature rise, smoothing out the operation of compressors.
Advantages of centralized cooling
The use of external cold provides enormous advantages in the operation of large areas. First of all, we are talking about saving energy. Modern units with frequency conversion (inverter) are able to smoothly change performance, consuming a minimum of energy while maintaining temperature.
The second plus is a reduction in heat flow in the sales area. Since the condenser (heat exchanger that heats the air) is placed outside, store air conditioners do not have to deal with excess heat from refrigerators. This is a double saving: the cold works less and the air conditioning works less.
| Parameter | Monoblock system | External cold system |
|---|---|---|
| Noise level in the hall | High (hum compressor) | None (only fan noise) |
| Heat dissipation | Significant | Minimal |
| Maintainability | Complex (you need to disassemble the display case) | Convenient (unit in the technical area) |
| Installation cost | Low | High (routes, commissioning) |
The third aspect is reliability and maintainability. Maintenance refrigeration machine is carried out in the technical room without disturbing customers. If one compressor in a cascade breaks down, the others continue to operate, maintaining the temperature, albeit with less efficiency. The products will not defrost instantly, as happens when a household appliance fails.
Disadvantages and technical limitations
Despite the obvious advantages, the system also has disadvantages. The main one is the high initial cost. The price compressor-condensing unitof large-diameter copper pipes and installation work can be several times higher than the cost of a set of conventional refrigerators. The payback of such a solution occurs in a few years.
The second drawback is the risk of refrigerant leakage. Because pipes often pass through ceiling spaces, basements, or attics, locating the fistula can be extremely difficult. Long lines require more refrigerant, which increases environmental risks and the cost of refilling.
⚠️ Attention: The length of the refrigerant line is strictly limited by the equipment manufacturer. Exceeding the permissible distance between the KKB and the farthest showcase will lead to a drop in pressure and the impossibility of returning oil to the compressor.
It is also worth noting the complexity of commissioning work. It will not be possible to launch such a system “by eye”. Requires fine tuning TRV (temperature expansion valves), checking superheat and subcooling, setting defrost timers for each evaporator. Errors at this stage are fatal to the life of the equipment.
Installation and placement requirements
Installation of the system begins with choosing a location for the unit. This could be the roof of a building, a technical extension or a well-ventilated basement. For street blocks, canopies protecting from precipitation and anti-vandal grilles are required. The base must be level and vibration-proof.
The laying of routes is carried out in compliance with the slopes. Horizontal sections must have a slope towards the movement of gas or liquid, respectively, to ensure oil transport. In vertical risers, it is obligatory double elbows or oil traps every few meters to prevent oil from flowing back into the evaporator.
☑️ Check before starting the system
Thermal insulation is an important step. All pipelines through which cold gas or liquid moves must be covered with a high-quality insulator (rubber, polyethylene). This prevents the formation of condensation ("sweating" of pipes) and loss of cooling capacity. The insulation thickness is calculated based on the diameter of the pipe and the boiling point of freon.
Operation and maintenance
Regular maintenance is the key to a long life refrigeration center. It includes cleaning the capacitors from dust and lint (especially in spring and autumn), checking the tension of fan belts, and checking the oil level. A dirty condenser increases condensation pressure, which leads to overload of motors and increased electricity bills.
Particular attention should be paid to the automation system. Controllers must display temperature correctly, and sensors must have minimal error. The operation of protections is periodically checked: for high and low pressure, for discharge temperature. These protections save compressors from destruction in emergency situations.
- 🔧 Monthly cleaning of heat exchangers.
- 📊 Taking readings of engine pressures and currents.
- 🔍 Visual inspection of insulation and pipe fastenings.
- 🧪 Oil analysis for acidity (if necessary).
In winter, operation has its own characteristics. If the condenser is located outside, it is necessary to use condensation pressure regulators (CPR) so that the pressure in the system does not fall below the permissible level. Otherwise thermostatic valve freon will stop supplying, and cooling will stop, despite the compressor running.
What to do if the remote refrigeration system stops freezing?
First of all, check the indication on showcase controller. If the alarm is on, look at the error code. Often the problem lies in a tripped compressor protection or lack of power to the condenser fan. It is dangerous to get into the electrical circuit yourself without permission - call a specialist.
Is it possible to connect a household display case to an industrial unit?
Theoretically, yes, if the refrigerant parameters match (usually R404A or R134a). However, household display cases are not designed for long routes and pressure drops. The installation of additional regulators (KRD, ZOR) and careful calculation will be required, so it is easier to use specialized commercial equipment.
How often do you need to change the oil in remote cold compressors?
In modern hermetic and semi-hermetic compressors, the oil is changed not according to a schedule, but according to the results of the analysis. If the system is sealed and there have been no accidents (for example, the winding burned out), the oil can work for years. Replacement is made when high acidity or loss of lubricating properties is detected.