Cold rooms are generally used in storing large quantities of products or goods that requires low temperature, it is important that you keep it in shape to operate smoothly and avoid fault problems. Following are the list of the most common cold room fault problems that you may encounter; what causes them and why and how best to solve them.
Cold room common fault problems and solutions
1. Initial operation of cold room refrigeration equipment: The initial process of cold room refrigeration equipment should always observe the oil level and oil return of the compressor and the cleanliness of the oil. It is assumed that the oil is dirty or the soil surface should be resolved in time to avoid inadequate lubrication.
2. Always observe the operating status of the heart compressor of the cold room refrigeration equipment: check the exhaust temperature. When operating in the season, pay special attention to the operating state of the system, and adjust the system liquid supply and condensation temperature in time.
3. Do not start for a long time or start the machine for a great time without stopping or the temperature of the cold room is not stopped: check whether there is dirt on the condenser, the heat dissipation will cause the condensing pressure of the refrigerator to be too high, in order to protect the compressor, in the pressure controller Under the action of the machine stops running, wait until the heat is good, press the black reset button on the voltage controller, the machine will automatically resume operation.
4. Usually by observing the changes of the instrument: listening to the sound of the machine running, touching the temperature changes of the organization and other methods to keep the operating state of the compressor found that the compressor has a string of gas and other phenomena should be repaired or replaced in time.
5. Cold storage room due to poor insulation or sealing performance, resulting in large loss of cooling capacity: poor thermal insulation performance of the cold storage is due to insufficient thickness of insulation layer of pipelines, warehouse insulation walls, etc., insulation and insulation effects are not sound, it is mainly designed insulation The thickness of the sheet is not selected correctly or the quality of the insulation material is poor during construction. Or the insulation and moisture-proof performance of the insulation material may be destroyed, causing the insulation layer to be damp, deformed or even smashed, and its thermal insulation capacity is decreased, and the loss of the cold storage capacity of the storage is made, and the temperature drop of the room is obviously slowed down.
6. The surface of the cold storage room evaporator is too thick or excessively dusty: the heat transfer effect is reduced to prevent the frost layer on the surface of the evaporator from being too thick, and it needs to be defrosted regularly. In addition to excessive frosting, the heat transfer effect of the evaporator is not good. The surface of the evaporator is too thick for long-term uncleaning, and its heat transfer efficiency is also significantly reduced.
7. There is more air or refrigeration oil in the evaporator: the heat transfer effect is reduced. Once the evaporator has more refrigerant oil on the inner surface of the heat transfer tube, the heat transfer coefficient will be reduced. Similarly, if the heat transfer tube is There is more air, the heat exchange area of the evaporator is reduced, the heat transfer efficiency is also significantly reduced, and the warehouse temperature drop rate is slowed down.
8. Improper adjustment or blockage of the cold room throttle valve: If the refrigerant flow rate is too large or the throttle valve is improperly adjusted or blocked, it will directly affect the refrigerant flow entering the evaporator. When the opening degree of the throttle valve is too large, the refrigerant flow rate is too large, and the evaporation pressure and the evaporation temperature also increase. Meanwhile, when the throttle valve opening degree is too small or blocked, the refrigerant flow rate also decreases, and the system flow rate is also reduced. The amount of cooling is also reduced.
Generally, by observing the evaporation pressure, evaporation temperature and frosting of the suction pipe to judge whether the throttle valve refrigerant flow is suitable, the throttle valve blockage is an essential factor affecting the refrigerant flow rate, and the leading cause of the throttle valve blockage is ice: blocking and dirty plugging. The ice blockage is due to the weak drying effect of the dryer. The refrigerant contains moisture. When flowing through the throttle valve, the temperature drops below 0 °C, and the humidity in the refrigerant forms ice and blocks the throttle hole; the dirty plug is Due to the accumulation of more dirt on the filter inlet of the throttle valve, the refrigerant flows poorly and forms a blockage.
9. Insufficient refrigerant amount in the refrigeration system: insufficient cooling capacity There are two main reasons for inadequate refrigerant circulation in the cold storage. First, the refrigerant charge is insufficient. In this case, only enough refrigerant can be added. One reason is that the system refrigerant leaks more. In the case of such a situation, the leak point should be searched first. The pipelines and valves should be inspected to find out the leaked parts and then filled with a sufficient amount of refrigerant.
10. The compressor efficiency is low: the cooling capacity cannot meet the warehouse load requirements. Due to the long-term operation of the compressor, the cylinder liner and piston ring and other components are dangerously worn. The matching clearance will increase, the sealing performance will decrease accordingly, and the compressor’s gas transmission coefficient will also follow. The reduction will reduce the cooling capacity. The refrigeration capacity of the compressor can be roughly estimated by observing the suction and exhaust pressure of the compressor. If the refrigeration capacity of the compressor drops, the standard method is to replace the cylinder liner and piston ring of the compressor. If it still fails to work after replacement, other factors should be considered, even disassemble and repair, and eliminate the fault factor.