Refrigeration compressor liquid strike, overheating cause analysis

Many low-temperature chiller units use original imported scroll compressors, so many customers also call them scroll chillers. Chillers in the operation process, often due to various problems resulting in compressor burnout, liquid strike and other phenomena.
Low-temperature chiller compressor liquid strike situation can lead to scroll disk damage, liquid strike failure phenomenon is generally manifested in the compressor can be heard inside the obvious sound of metal impact, which is the scroll disk was shattered after the metal fragments hit each other or with the compressor shell impact sound.
There are mainly the following cases of liquid shock:
First, a large amount of refrigerant liquid into the compressor at the moment of start-up, or the compressor is not preheated;
Second, the evaporator flow is not enough (section hair load reduction), the compressor has a liquid back phenomenon;
Third, the unit heat pump operation defrost is not good, a large number of liquid refrigerant does not evaporate into the compressor
Four, four-way valve reversal moment evaporator liquid into the compressor.
How do we solve the problem of liquid strike or liquid return?
1, the pipeline design to avoid the start-up liquid refrigerant into the compressor, especially the charge is relatively large refrigeration system. In the compressor suction port to increase the gas-liquid separator is an effective way to solve this problem, especially in the use of reverse cycle hot gas defrost heat pump unit.
2, before starting, the oil chamber of the chiller compressor for a long enough time to preheat can effectively avoid a large number of refrigerant accumulated in the lubricant. For the prevention of liquid shock also has a certain effect.
3, the water system flow protection is indispensable, so that when the water flow is not enough to play a role in protecting the compressor, in order to master the unit has back to the liquid phenomenon or when the seriousness of the frozen evaporator.
4, refrigeration compressor before starting to preheat, preheat the reasons at the end of this article has detailed instructions.
Chiller equipment compressor overheating is the reason? We analyze from three aspects:
First, the compressor load is too large, overcurrent operation. Maybe the factors are: cooling water temperature is too high, refrigerant charging too much or refrigeration system within the air and other non-cohesive gases, resulting in a large compressor load, manifested as overcurrent, accompanied by high-pressure problems.
Second, electrical problems form low-temperature freezer compressor overcurrent operation. Such as three-phase power supply voltage is too low or three-phase imbalance, resulting in current or a phase current is too large; communication contactor damage, contact erosion, resulting in contact current is too large or due to lack of phase and current is too large.
Third, the low-temperature freezer overheating maintenance module is damp or damaged, the center relay is damaged, bad contacts, the performance of the boot is overheating problems, the compressor can not start. If the unit electronic board problems or communication problems, may also be false reporting overheating problems.
Why should the chiller start preheating
Refrigeration system a lot of refrigerant and compressor refrigeration oil has a certain solubility, when the refrigeration system stops, there is a certain pressure in the system, a considerable portion of the refrigerant will be dissolved in the refrigeration oil, the amount of dissolved with the increase in pressure, with the increase in temperature and decrease, if there is no measure, start the compressor crankcase when the pressure is reduced, a large number of refrigerants will boil from the oil, making the oil produce foam, which is sucked by the compressor. So that the oil produces foam, which is inhaled, compressed and discharged by the compressor, and as a result, the compressor liquid shock or lack of oil.
In order to avoid this situation, the unit should be energized 8 hours before start-up when it is not started for a long time, the heating works automatically after the unit is energized, and the oil heating stops automatically when the refrigerator is running. If the unit is not regularly turned on, since the unit to be unplugged can be. Refrigeration wikipedia tips, this preheating time has no fixed value, for example, some refrigeration machine before the first boot is a certain requirement of 24 hours of energization, other manufacturers have 12 hours, but longer and safer, 24 hours is enough.
In addition, large refrigeration compressor start-up torque is large, in the case of low temperatures, the refrigeration oil due to the role of temperature thickening, will form a resistance, resulting in damage to the compressor. Therefore, large refrigeration dryers need to use heating tape to preheat before starting, the temperature rise will make the refrigerant gasification, lubricating oil viscosity is reduced, so that the compressor can work better.
Xinxiang Yukun Refrigeration Technology Co. is a production and sales of refrigeration two apparatus parts and sheet metal products, mainly engaged in condenser, evaporator, heat exchanger, reservoir, filter drier, Fin Evaporator (condenser), Stamping Parts, sheet metal parts, aluminum tubes for refrigeration, etc.

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Our company mainly produces products for:Fin Evaporator.Fin Type Condenser.Capillary Tube.Aluminum Coolant Reservoir.Plate Reinforcement Parts.Stamped Parts.Aluminum Tube.Instrument Testing Equipment.
Supermarket Refrigeration Show Case Copper Condenser Coil
1. OEM or ODM can be accepted
2. Fin type: Louver or corrugated
3. Be customerized according to samples and drawings.
4. High quility and low price and energy saving 60% (CE, RoHS, EMC and ISO9001 certification) The CD series products can be used in Various specificantion Condensing Units .