The outlet temperature or exhaust temperature of the machine head is high
High temperature is a common fault during the operation of screw air compressor, screw air compressor often runs at high temperature, which will seriously affect the exhaust volume and service life of the machine. When the temperature rise is too high, a high-temperature shutdown failure will occur. The reasons are:
1. Temperature sensor failure. The failure of the temperature sensor will cause the PLC to falsely alarm that the temperature is too high, causing downtime.
2. Ambient temperature factors. The outlet temperature of the head of the screw air compressor is generally set at about 110 °C, while the outlet temperature of the head is equal to the ambient temperature plus 60 °C. The ventilation environment is poor, and most of the high temperatures are caused by this.
3. Temperature control valve failure. When the compressor is cold started, the temperature control valve can make the oil bypass the cooler and directly inject into the main engine, accelerate the rise of the oil temperature, prevent condensation in the compressor, and after the normal operation of the compressor, the proportion of oil flowing through the cooler and the road can be adjusted according to the oil temperature, and the fuel injection temperature can be controlled. If the temperature control valve is damaged or the action is not sensitive, a large amount of high-temperature oil will be directly circulated into the main engine head without the cooler, resulting in high temperature of the main engine.
4. Oil filter failure. The oil filter is used to filter dust and impurities in the oil circuit, which is easy to clog after a period of use, and the temperature of the host is high (often at the moment of loading) caused by poor oil return after blockage.
5. The oil shut-off valve is faulty. The oil shut-off valve is to control its reciprocating movement of oil injection through the air pressure of the gas storage tank, if the failure causes the oil circuit to be unsmooth, causing the oil temperature to be high; Debris blocks the oil circuit or controls the gas path, causing the oil shut-off valve to close and not inject oil, which will also cause the main engine head to have a high temperature due to lack of oil or poor heat dissipation of less oil.
6. The amount of lubricating oil is insufficient, the oil cooler is dirty and blocked, which will cause the temperature to be too high.
7. The cooling fan fails, the air cooler is blocked, and the exhaust resistance is too large, resulting in poor heat dissipation and high temperature. The outside of the cooler should be cleaned of dust and internal oil.
8. The unloading pressure setting is too low, resulting in too much oil resistance of the air compressor during the unloading cycle, and the flow rate is too slow, resulting in heat not being dissipated in time, resulting in high temperature shutdown failure. Therefore, the unloading pressure should be set reasonably.
Low exhaust pressure
1. The gas production of the unit is less than the actual gas consumption, first, the air compressor is selected small, and the second may be caused by leakage. The connected equipment and pipe network should be inspected, and if there are leaks, they should be repaired in time. If under normal use conditions, the air consumption of the system is greater than the air output of the compressor unit, the large-sized compressor unit should be replaced or the compressor unit should be increased.
2. The unloading pressure setting is too low. Set the unloading pressure value correctly to maximize efficiency.
3. The air filter element is dirty and blocked, resulting in insufficient air intake of the compressor unit and low exhaust pressure. The condition of the air filter should be checked and replaced if necessary.
4. Solenoid valve failure. The main bleed solenoid valve and the cold-start venting solenoid valve on the exhaust line leak and need to be replaced.
5. Control the leakage of the air path hose. Replace the control air hose
6. The intake valve is not sensitive and is not fully opened. The condition of the control system needs to be overhauled and checked.
7. The oil separator is blocked, and the oil separator filter element needs to be replaced.
8. Safety valve leakage. The valve needs to be recalibrated or replaced.9. The
drain valve of the gas-water separator is stuck after opening, causing leakage, and should be repaired.
10. The venting valve is faulty, and the compressor unit cannot be closed when it is loaded. Requires overhaul or replacement.
The exhaust pressure is too high
1. Failure of the intake valve. Requires service or replacement.
2. The loading and unloading pressure value is not set reasonably. The loading and unloading pressure value needs to be set according to the actual air consumption.
3. Pressure sensor failure. Replacement.
4. The unloading valve is not closed, the unloading valve is stuck or not closed tightly, and the solenoid valve fails. Overhaul unloading valves and solenoid valves are replaced if necessary.
Frequent loading and unloading
1. The setting of the loading and unloading pressure difference is too small, reset the loading and unloading pressure value (pressure difference above 1bar is appropriate).
2. The pressure sampling tube is blocked or leaking, and the pressure decay is too fast. The sampling line needs to be serviced.
3. The actual air consumption of production is unstable, sometimes large and small or discontinuous. An air receiver can be added after the compressor unit.
4. The minimum pressure valve is not closed in time or closed strictly. Overhaul the minimum pressure valve and replace it if necessary.
5. Loading control solenoid valve failure. The solenoid valve should be checked, which may be affected by oil, water and gas causing insensitive action or coil burnout. Check and replace if necessary.
6. The pressure sensor that controls the start and stop of the unit is faulty or damaged. Should be serviced and replaced.
7. The pipeline filter on the pipeline at the rear end of the compressor is seriously blocked, and it can be verified whether it is caused by the filter bypass.
It is always loaded and not unloaded (similar to the reason for low exhaust pressure).
1. The actual air consumption is greater than the air volume produced by the compressor unit, and the compressor unit has been in the state of loading operation.
2. Check whether there is air leakage in the connected pipe network.
3. Check whether the loading and unloading solenoid valve is active or damaged.
4. Check whether the inlet valve of the compressor unit is closed tightly.
5. Check whether the drain valve of the gas-water separator has leakage.
6. Check whether there is internal leakage in the safety valve and oil separator.
Excessive fuel consumption/exhaust compressed air contains oil
1. Refuel too much. If the oil level is too high, the air flow will engulf the oil in the oil separator into the compressed air. Cause the oil content in the exhaust compressed air to exceed the standard. Therefore, the amount of fuel should be controlled within the oil level marking.
2. The failure of the minimum pressure valve spring leads to too low opening pressure, the pressure difference between the front and rear of the oil separator is too large, the oil and gas mixture gas flow rate in the tank is high, and the condensed oil on the cylinder wall and the oil separator filter element will be taken away by the high-speed air flow, thus affecting the oil and gas separation effect.
3. The filter element of the oil separator is blocked or damaged, and replaced.
4. The oil return pipe of the oil separator is blocked, check and clean.
5. There is a leak in the air cooler system, check and repair and make up the leakage.
6. The oil use time is overdue and the oil quality deteriorates. Clean the compressor unit and replace with qualified oil.