What are the common protections for water cooled chiller system?
High pressure protection: High pressure protection is to detect whether the refrigerant pressure in the system is normal. When the pressure exceeds the allowable range, the pressure switch acts and sends the abnormal signal to the high pressure controller. After processing, the refrigeration system will stop working and the fault will be displayed.
Low pressure protection: The low pressure protection detects the return gas pressure in the system, which is used to prevent the compressor from being damaged due to low system pressure or no refrigerant running in the system.
Oil pressure protection: a device to prevent the bearing or other internal components of the compressor from being damaged due to the lack of oil due to the low lubricating oil pressure. If the oil quantity of the compressor is reduced or cut off, the compressor running at high speed will be seriously damaged. The oil pressure protection device is an important part to ensure the safe operation of the compressor.
Anti freezing protection: if the evaporator is too dirty or frosting is too serious, the cold air cannot fully exchange heat with the outside hot air at this time, causing the internal machine to freeze. The indoor anti freezing protection is to stop the compressor before the internal machine freezes, playing a role in protecting the compressor.
1. What is the cause of low exhaust pressure of GX/GY -65°C ~ -10°C Industrial Refrigerators?
The exhaust pressure is lower than the normal value. The factors include low compressor efficiency, insufficient refrigeration dosage, small cooling load, small expansion valve opening, blocked filter, including low temperature of expansion valve filter screen and cooling medium.
The above factors will cause the cooling flow of the system to drop, the condensation load to be small, and the condensation temperature to drop.
From the above changes of suction pressure and exhaust pressure, they are closely related. In general, when the suction pressure rises, the exhaust pressure also rises accordingly; The suction pressure drops and the exhaust pressure drops accordingly. The general situation of exhaust pressure can also be estimated from the change of suction pressure gauge.
2. How to deal with the solenoid valve failure of water-cooled refrigerator?
⑴ The reason why the valve cannot be opened after the power supply is turned on may be that the voltage is too low, and the solenoid valve cannot work normally: the coil connector is poorly contacted or the coil is short circuited。
the installation position of the solenoid valve is not correct or the iron core is contaminated with oil, which causes the iron core to be stuck; the pressure difference between the inlet and outlet exceeds the development capacity, which makes the iron core unable to suck, or the specification of the solenoid valve is used to match the equipment department. The treatment method is to adjust the voltage, repair the coil, clean or select an appropriate solenoid valve.
⑵ The reason for untimely closing is that the small hole at the side of the valve plug is blocked and the spring strength is weakened. The treatment is to clean the small hole and replace the spring.
(3) The sealing is not tight and the leakage is caused by being stuck by dirt and impurities, the sealing ring on the valve plug is worn, and the solenoid valve is installed reversely and the pressure before and after the generator is lower than the nominal pressure. The treatment is to clean, replace the seal ring and adjust it correctly.