As a key device for maintaining a constant temperature environment, the normal operation of each component of the refrigeration unit is crucial. When a refrigeration unit fails, quickly and accurately diagnosing the problem and taking appropriate solutions are the key to restoring the normal operation of the unit.
The main components of the refrigeration unit include the compressor, condenser, expansion valve, evaporator, fan and condenser drainage system. The following is an overview of the analysis and solutions for the failure of each component of the refrigeration unit:
I. Compressor Failure:
1. The compressor cannot start normally. Common causes of failure are
(1) The energy adjustment of the compressor has not dropped to the minimum allowable load
a. The load sensor is not calibrated correctly. Solution: Adjust the energy adjustment to 0% load before starting.
b. The load slide valve is faulty. Solution: Return to the factory for disassembly and repair.
(2) The coaxiality eccentricity between the compressor and the motor is large. Solution: Re-adjust the coaxiality.
(3) The compressor is worn or broken. Solution: Return to the factory for disassembly and repair.
Fracture
Wear and Tear
2. Handling of mechanical faults
(1) The compressor is difficult to start or cannot start: Check the power supply voltage and wire connection, confirm whether the compressor motor and starting device are damaged; check whether the capacitor capacity is too small or has failed, and replace the capacitor; check the patency of the main pipeline and valve, and check whether the condenser and evaporator are scaled or dusty.
(2) The compressor noise is too loud: Check whether the compressor connecting rod bearing, cylinder seal, filter, suction pipe and exhaust pipe are loose or damaged, and make necessary repairs or replacements.
(3) The compressor exhaust pressure is too high or too low: Check whether there is blockage in the condenser or exhaust pipe, insufficient cooling water flow, excessive compression ratio or too little lubricating oil, and take corresponding measures.
3. Handling of electrical faults
(1) The compressor motor does not rotate: Check whether the power supply is normal, whether there is phase loss, overload protection startup or open circuit, and repair or replace it in time.
(2) The compressor current is abnormal: Check whether the wiring of the electrical control cabinet is correct, whether there is electric shock, short circuit and other problems, and make necessary repairs or replacements.
4. Troubleshooting of control system
(1) Unstable operation of compressor: Check whether there are any problems such as parameter setting errors, sensor failure or software failure in the control system, and perform correct debugging and repair in time.
(2) Automatic stop of compressor: Check whether the control system has any fault signal output, such as sensor failure, overload protection activation, etc., and handle them in time.
II. Failure of Condenser of Refrigeration Unit
It may be caused by many reasons, including but not limited to insufficient cooling water flow, high cooling water temperature, air in the system, excessive refrigerant filling, excessive dirt in the condenser, etc.
1. Check the installation and pipe connection of the condenser: Make sure that the condenser is firmly installed without looseness or displacement, and check whether the pipe connection is tight to prevent air leakage. If air leakage is found, it can be repaired by welding or replacing the pipe.
2. Repair or replace leaking parts: If the condenser has air leakage, blockage and corrosion, it is necessary to repair or replace the corresponding parts according to the specific situation. For example, if the air leakage is caused by aging or damage of the seal, the seal needs to be replaced.
3. Clean or replace the condenser: If the condenser is too scaled or severely blocked, it may need to be disassembled, cleaned or replaced with a new condenser. Use clean water and perform appropriate chemical treatment on the cooling water to prevent the formation of scale. 4. Adjust the cooling water volume and temperature: If the condensation temperature is too high or too low, it may be because the cooling water volume is insufficient or the cooling water temperature is too high. Sufficient water needs to be added and appropriate cooling measures need to be taken for the cooling water to ensure the normal operation of the condenser.
5. Scale treatment: Regularly descale the condenser and use appropriate chemical or mechanical methods to remove scale to prevent excessive scale from causing a decrease in heat exchange efficiency and equipment damage.
Ⅲ. Expansion Valve Failure
1. The expansion valve cannot be opened: When the expansion valve in the refrigeration system cannot be opened normally, the refrigeration effect decreases, and eventually the refrigeration cannot be normal. This failure phenomenon is mostly caused by damage to the internal structure of the expansion valve or the jamming of the expansion valve core. To solve this problem, it is necessary to check whether the internal structure of the expansion valve is normal, whether there is jamming, and perform corresponding maintenance and maintenance.
2. The expansion valve cannot be closed: When the expansion valve cannot be closed normally, the refrigeration effect will also decrease, and eventually the refrigeration system will be abnormal. This kind of fault phenomenon is mostly caused by damage to the internal valve core of the expansion valve or poor sealing of the valve body. The solution is to check whether the valve core is normal, clean the valve body and replace the seal.
IV. Failure of The Evaporator of The Refrigeration Unit
Common causes of failure mainly include circuit or pipeline connection failure, severe frost or no defrosting, internal pipe blockage, insufficient water flow, foreign matter blockage or scaling.
1. Circuit or pipeline connection failure: Due to circuit aging, human damage, insect and rodent damage, etc., the connection between the evaporator wire and the copper pipe may be disconnected or loose, causing the fan to not rotate or the refrigerant to leak. The maintenance method includes checking the connection of wires, pipes, etc., and re-strengthening the connection.
2. Severe frost or no defrosting: Due to long-term non-defrosting and high humidity in the warehouse, the surface of the evaporator may be severely frosted. If the defrosting device such as the heating wire or water spraying equipment on the evaporator fails, it will cause difficulty in defrosting or no defrosting. Maintenance methods include checking the defrost device, repairing or replacing the defrost device, and using tools to manually defrost.
3. Internal pipe blockage: The presence of debris or water vapor in the refrigeration system may cause the evaporator pipe to be blocked. Maintenance methods include using nitrogen to blow out dirt, replacing refrigerants, and removing debris and water vapor in the refrigeration system.
4. Insufficient water flow: The water pump is broken, foreign matter has entered the water pump impeller, or there is a leak in the water pump inlet pipe, which may cause insufficient water flow. The treatment method is to replace the water pump or remove foreign matter in the impeller.
5. Foreign matter blockage or scaling: The evaporator may be blocked or scaled due to insufficient heat exchange caused by foreign matter entering or crystallizing. The treatment method is to disassemble the evaporator, rinse it with a high-pressure water gun or soak it in a special liquid for cleaning.
Ⅴ. Refrigeration Unit Fan Failure
The treatment method for refrigeration unit fan failure mainly includes checking and repairing fans, sensors, circuits, and control software.
1. The fan does not rotate, which may be caused by damage to the fan motor, loose or burned connection lines, etc. In this case, you can consider replacing the fan motor or repairing the connection line to restore the normal operation of the fan.
2. The refrigeration equipment is equipped with various sensors for monitoring parameters such as pressure and temperature. Sensor failure may also cause the fan to not turn. In this case, you can try to clean or replace the sensor to ensure that the sensor is working properly.
3. Circuit failure is also a common cause, which may be caused by a short circuit in the power supply line, a blown fuse, or a switch failure. In this case, you can check the power supply line, replace the fuse, or repair the switch to ensure that the circuit power supply is normal.
4. Refrigeration equipment is usually operated and monitored using an electronic control system. If the control software fails, it may cause the compressor working fan to not turn. In this case, you can try to restart the refrigeration equipment or update the control software to fix the software failure.
Ⅵ. Failure of The Condenser Drainage System of The Refrigeration Unit
The treatment methods mainly include checking and cleaning the water pan, condensate pipe, and solving the air outlet problem.
1. Check and clean the water pan: If the condensate leakage is caused by uneven installation of the water pan or blockage of the drain outlet, the air conditioner should be adjusted to the normal installation slope or the drain outlet should be cleaned.
The cleaning method for the blockage of the drain outlet of the water pan includes finding the drain outlet, poking the debris in the drain outlet with a small screwdriver or other stick-like object, and flushing the indoor unit evaporator with clean water to remove the blockage.
2. Check and repair the condensate pipe: If the condensate pipe is poorly installed and the drainage is not smooth, the damaged part of the drain pipe should be checked and repaired, and the drain pipe of the same material should be replaced.
The condensate leaks caused by the damage or poor wrapping of the insulation cotton of the drain pipe. The damaged position should be repaired and ensured to be well sealed.
3. Solve the problem of air outlet: If the problem of air outlet causes the condensate to flow poorly, the indoor evaporator should be cleaned and the indoor fan speed should be adjusted.
The problem of condensation and leakage of aluminum alloy air outlets can be solved by replacing ABS air outlets, because condensation and leakage are usually caused by high humidity.
The above are the common causes and solutions for the failure of several main configuration components of the refrigeration unit. In order to reduce the failure rate of these components, the user unit needs to regularly maintain and inspect the refrigeration unit to ensure the normal operation of the refrigeration unit.
Post time: Dec-17-2024
