If we want to build a cold storage, the most important part is the refrigeration part of the cold storage, so it is very important to choose a suitable refrihgeration unit.
Generally, the common cold storage units on the market are divided into the following types
According to the type, it can be divided into water-cooled units and air-cooled units.
Water-cooled units are more limited by ambient temperature, and water-cooled units are not recommended in areas below zero.
The most popular in the whole market is air-cooled refrigeration units. So let us focus on air-cooled units.
To learn a refrigeration unit, we must first understand the structure of the unit
1. Refrigeration Compressor
The types of common cold storage compressors are as follows: Semi-hermetic cold storage compressor, screw cold storage compressor and scroll cold storage compressor.
3. liquid reservoir
It can ensure stable refrigerant liquid flow to the end.
The liquid reservoir is equipped with a liquid level indicator, which can observe the change of liquid level and whether there is too much or too little refrigerant in the system according to the load.
4. Solenoid valve
The solenoid valve coil is energized or de energized to realize the automatic on-off of the pipeline
Scroll compressor
When the cold storage and cooling capacity requirements are small, the scroll compressor can be used.
2. Oil separator
It can separate the refrigerant oil and refrigerant gas in the exhaust.
Generally, each compressor is equipped with an oil separator. High temperature and high pressure refrigerant vapor and refrigerant oil flow in from the oil inlet, and the refrigerant oil is left at the bottom of the oil separator. Refrigerant vapor and a small amount of refrigerant oil flow out from the oil inlet and enter the condenser.
5. Condenser part
As an important heat exchange equipment in the refrigeration system, heat is transferred from the superheated refrigerant vapor with high temperature and high pressure to the condensing medium through the condenser, and the temperature of the refrigerant vapor gradually drops to the saturation point and condenses into liquid. Common condensing media are air and water. The condensation temperature is the temperature at which the refrigerant vapor condenses into a liquid.
1) Evaporative condenser
Evaporative condenser has the advantages of high heat transfer coefficient, large heat emission and wide application range.
When the ambient temperature is relatively low, stop the fan operation, only turn on the water pump and use the water-cooled refrigerant alone.
When the temperature drops below the freezing point, pay attention to the antifreeze of water.
When the system load is small, on the premise of ensuring that the condensation pressure is not too high, the operation of evaporative cooling circulating water pump can be stopped and only air cooling can be used. At the same time, the water stored in the evaporative cold water tank and connecting water pipe can be discharged to prevent freezing, but at this time, the air inlet guide plate of evaporative cooling should be completely closed. The precautions for the use of water pump are the same as those of water condenser.
When using evaporative condenser, it should be noted that the existence of non condensable gas in the system will significantly reduce the heat exchange effect of evaporative condensation, resulting in high condensation pressure. Therefore, air release operation must be carried out, especially in the low-temperature system with negative suction pressure of refrigerator.
The pH value of circulating water shall always be maintained between 6.5 and 8.
2) Air cooled condenser
The air-cooled condenser has the advantages of convenient construction and only providing power supply for operation.
Semi-hermetic cold storage compressor
When the refrigeration capacity of the cold storage is required to be large but the scale of the cold storage project is small, the Semi-hermetic cold storage compressor is selected.
The air condenser can be installed outdoors or on the roof, which reduces the occupation of effective space and the requirements for users' installation site. During long-term operation, avoid placing sundries around the condenser to avoid affecting the air circulation. Regularly check whether there is suspected leakage such as oil stain, deformation and damage on the fins. Regularly use high-pressure water gun for flushing. Be sure to cut off power and pay attention to safety during flushing.
Generally, the pressure is used to control the start and stop of the condensing fan. Because the condenser operates outdoors for a long time, dust, sundries, wool, etc. are easy to flow through the coil and fins with the air and adhere to the fins with the passage of time, resulting in the failure of ventilation and the increase of condensing pressure. Therefore, it is necessary to regularly check and keep the fins of air-cooled condenser clean.
screw type cold storage compressor
When the refrigeration capacity of the cold storage is relatively large and the scale of the cold storage project is large, the screw type cold storage compressor is generally selected.
Post time: Apr-15-2022