The operation of each refrigeration unit is provided by special units and control systems. The functions of the main part of the equipment are compression, cooling and condensation of vapors. The condensing unit is a special purpose unit that changes the state of the refrigerant depending on the ongoing process.
The selection of this equipment depends on the ambient temperature, the capacity of the chamber and, directly, the purpose. There are several types of installations: air-cooled and water-cooled.
The machine is powered by a motor (electric motor). Small capacity condensing unit can be used in industrial refrigerators, air conditioners, household refrigeration appliances.
Small, low noise machines have the following advantages:
- Able to use in small spaces.
- Simplified installation and maintenance.
- Small.
- Strength and durability of the structure.
Component parts of the unit
The main part of any refrigeration unit comes ready-made from the manufacturing plant. Pipes and fittings that are under high pressure are tested before assembly. The electrical circuits and the control panel are also tested. Upon receipt of the device, you should check the integrity of the package, case. If all the characteristics are normal, you can connect the condensing unit to the refrigeration unit.
Basic composition of the device:
- High pressure switch. The purpose is to control the cooling system (fans).
- Control panel. The latter consists of a thermostat (responsible for the automatic start / stop of the compressor), a fan speed controller. The process of the motor is responsible for turning the heater on and off.
- Dual relay (high and low pressure). Such a device works in emergency situations.
- Compressor. This unit is filled with oil, as well as a heater for heating it. Pressure sensors are installed on the suction and discharge lines of the refrigerant.
- Vibro- and noise isolation.
Specifications
Comparatively "quiet" condensing units are used for small shops, gas stations and other low-budget businesses. They emit noise and vibration vibrations that are acceptablewhen operating in the residential sector.
The purpose of these devices is to create an artificial lowering of the operating temperature in small commercial and air-conditioning equipment.
The units operate with explosion-proof refrigerants (R22, R404A, R407C, R507). In addition, these liquids do not ignite and do not destroy the planet's ozone layer.
Low temperature performance ranges from 3.8 to 17.7 kW, depending on the selected fluid.
Control is performed by starting and stopping according to signals from external devices and sensors (eg thermostat). When the required level of cold is reached, the compressor automatically turns off, and when the set temperature rises, it turns on.
The condensing unit has comprehensive protection: against overheating of the windings, fans, high pressure, unsuitable voltage in the network.
Stages of design and development of units
- First of all, you need to get the parameters: latitudinal zone, temperature range, room or chamber volume.
- The next step is to calculate the power consumption.
- Next, related equipment is selected, working diagrams and drawings are developed.
- A frame or suspension system is designed to install a refrigeration condensing unit.
- On the selected frame, all necessary devices and related devices are installed.
- Next, the pre-testedpiping (copper or steel).
- Last of all, the automation and control system is connected.
Compact Coolers
Compressor-condenser units AK are used to obtain low temperatures in small devices. The latter are ideal for use in mobile devices, air conditioning systems, as well as for individual devices for quickly lowering the temperature.
The main characteristics of AK are:
- Main power: 230/400 V.
- Operating temperature range: 35-60◦C.
- Power consumption: 1-30 kW (for medium temperature) and 0.5-20 kW (for low temperature).
- Refrigerating capacity: 2-70 kW.
- Used refrigerant: R404A, R134A.
Economic appliances
To maintain temperatures during storage of products with a short shelf life, medium-temperature compressor-condensing units are used. Such devices are able to maintain a level from -5 to +14 (◦С).
For small cameras, monoblocks are designed that can be operated at ambient temperatures up to +40◦С. In this case, the compressor unit and the cooler are installed in one unit. The requirements for working in such conditions are: thick walls of the room (from 200 mm), the presence of additional equipment.
Split systems are used on large areas. In the latter, the condensing unit is located separately from the cooler.
Single-stage air-cooled units
Compact and optimized designs that run on a safe, certified fluid and have improved performance are popular in many countries.
Bitzer condensing units stand out among them. The main characteristics and advantages of devices of this type include:
- Wide range of cooling capacities.
- Design reliability.
- Compact.
- Wide range cooling (normal, low temperature).
- Large heat exchanger area.
- Increased protection of electrical controls and boards.
- Regulation of engine operation.
- Essential oil charge available (for some types of refrigerants).
By correctly determining the required cooling capacity, it becomes possible to choose the most economical and most reliable device that will ensure uninterrupted operation over a long period.
