The choice of cold storage condenser is mostly configured according to the actual situation of the cold storage project.
The air-type condenser is the most widely used cold storage condenser at present. It has many advantages such as simple structure, low price, few wearing parts, convenient installation and wide range of use, which is favored by customers. Air-type cold storage condensers are generally suitable for small and medium-sized cold storage equipment, and there are also use cases in large-scale cold storage projects in areas with depleted water sources.
The air condenser series is a radiator specially designed for semi-hermetic and fully-hermetic compressors; there are four types of production: FN type, FNC type, FNV type and FNS type; FN type, FNC type , FNS type adopts side outlet type, FNV type adopts top outlet type.
Using 3/8″ copper tube and pockmarked aluminum sheet, the aluminum sheet and copper tube are closely attached by mechanical expansion tube, and the heat exchange efficiency is high. ; It can be used for R22, R134a, R404A and other refrigeration working fluids, and is widely used in various Freon refrigeration equipment. FNS type condensers use high-power, large air volume, low-speed motors, and built-in installation, beautiful appearance, low noise, can be It can be used in units with low noise; FNV type condenser has a large windward side, good heat exchange effect, and is equipped with a 6-pole motor with low noise; it can be used in larger condensing units; various types can be designed according to customer requirements Air Condenser.
Cold storage users usually pay more attention to the heat exchange area of the condenser in the unit, mainly because they are worried that if the heat exchange of the condenser is too small, the condensing pressure will be too high during the summer operation of the equipment, resulting in equipment shutdown for protection; but many people ignore the low condensing pressure. If the pressure of the condenser is low, the pressure drop across the expansion valve will be reduced, and the refrigerant obtained by the evaporator will be small, thus causing the refrigeration system to fail.
In refrigeration systems, if the condenser is installed outdoors, the discharge pressure (condensing pressure) of the system tends to be lower in winter (or in low temperature environments).
This situation is often more common in the north. For air conditioners, it also exists for cold storage equipment. If the condensing pressure is too low, the expansion valve will not be able to obtain sufficient pressure drop across its two ends, making it difficult to provide the evaporator with proper pressure. On the one hand, the cooling capacity of the system cannot meet the requirements, and it will also cause frequent low-pressure alarms and other faults in the system.
In the low temperature environment in winter, the refrigeration system is prone to the failure of the condensation pressure being too low, so is there any way we can avoid the condensation pressure being too low in the low temperature environment?
1. Use the exhaust pressure controller to control the intermittent operation of the fan;
The intermittent operation of the fan is simple and easy to use, and the technology is mature. The controller used is a pressure controller, which can control the intermittent start and stop of the fan;
When the pressure is too low, turn off the fan; when the pressure is too high, turn on the fan; single high pressure can be selected, such as Danfoss KP5, etc., and the pressure setting value is set according to the actual situation.
Generally, on small-capacity units, two or more fans are used, one of which is normally open, and the rest of the fans are controlled by a pressure controller. The start or stop of the fans is controlled by the level of condensing pressure.
2. Control the speed of the condenser fan;
The method of fan speed control is also a method that has been relatively mature for many years. The main electrical components used are frequency converters (three-phase) or speed governors (single-phase).
The main working principle is through the feedback model of exhaust pressure (condensing temperature) (1~5V or 4-20ma signal).
Input to the frequency converter (speed governor), the frequency converter outputs (0~50HZ) to the fan according to the setting, and realizes the variable speed operation of the fan.
But usually the price is relatively high.
3. Use the damper or fan to operate intermittently to control the air flow;
The main component is the louvered air volume control device. The principle is to use a piston-type regulating damper driven by high-pressure refrigerant. This control device can obtain stable exhaust pressure like the fan speed controller;
The most important thing is that the inlet pressure of the expansion valve will not fluctuate greatly like the intermittent operation of the fan.
The shutter device can be set either at the air inlet or at the air outlet;
4. Adopt condenser overflow device.
The working principle of the condenser overflow device is to use excess refrigerant to increase the condensing pressure of the system.
The condenser overflow device is used in warm or low temperature environments to send a large flow of refrigerant from the accumulator to the condenser, and use the excess refrigerant to increase the condensing pressure of the system, so as to avoid the condensation pressure being too low at low temperatures. Fault.
Post time: Apr-18-2022
