1Low temperature refrigeratorThe principle of refrigeration process:
When the power is turned on, when the temperature displayed on the panel is higher than the set temperature, the * stage compressor starts first, and the * stage refrigeration system starts working, causing the condenser temperature of the second stage refrigeration system to decrease, that is, the refrigerant temperature of the second stage to decrease. After a few minutes of delay, the second stage refrigeration system also starts working. Its evaporator is on the inner wall of the refrigerator, which can cause the internal temperature of the refrigerator to drop a lot. The heat released by its condenser is absorbed by the evaporator of the * stage refrigeration system, and the heat released by the * stage condenser is dissipated into the air.
When the internal temperature of the low-temperature refrigerator reaches the set temperature, the temperature sensing probe resistor transmits information, the control relay loses power and disconnects, and the two-stage refrigeration system stops working. When the temperature inside the ultra-low temperature refrigerator rises again and exceeds the set temperature, the ultra-low temperature refrigerator repeats the above operation process again, so as to keep the temperature inside the refrigerator at around the set temperature.
2、 Maintenance and upkeep of low-temperature refrigerators
The maintenance and upkeep of low-temperature refrigerators are particularly important for extending their lifespan and normal use. If the temperature control is not accurate, it often leads to damage to the stored objects, which greatly affects the experimental results and thus affects the normal progress of research work.
1. Clean once a month to ensure its cleanliness
Use a dry cloth to remove a small amount of dust from the inside and outside of the refrigerator and accessories. If the refrigerator is too dirty, use a neutral detergent, clean it, and then rinse with purified water. But do not flush water inside or on the top of the refrigerator, otherwise it will damage the insulation material and cause malfunctions. The compressor and other mechanical parts do not require the use of lubricating oil. Be careful when cleaning the fan at the rear of the compressor. After cleaning, conduct a safety check to ensure that the refrigerator plug is properly plugged in and not disconnected; Ensure that the plug has no abnormal heat; Ensure that the power and distribution wires on the back of the refrigerator are not cracked or scratched.
2. Insufficient cooling of low-temperature refrigerator
Check if there is frost on the surface of the evaporator; Whether the refrigerator door is opened and closed too frequently; Is the back of the refrigerator in contact with the wall; Are there too many people and items placed.
3. Excessive noise from the refrigerator
Check if the bottom plate is sturdy; Is the refrigerator stable; If unstable, adjust the movable screws to firmly support the four corners on the base plate; Is there any object in contact with the back of the refrigerator.
If the refrigeration effect is poor, the refrigerator does not stop, the heat dissipation pipes are not hot, and the evaporator has a very small airflow sound, these are due to slow leakage causing serious refrigerant damage.
