I. Key Checks before Startup
1. Mechanical State Confirmation – Manually turn the pump by hand to confirm there is no jamming. The coaxiality deviation of the coupling should be less than 0.05mm. – Check the filling amount of bearing grease (about 1/3 of the bearing chamber volume) to avoid over – filling, which may lead to poor heat dissipation. – Open the inlet and outlet valves to ensure the pump body is filled with thermal oil and air is completely discharged, preventing cavitation during startup.
2. Pre – heating Process Execution – After starting the motor, let it run at low speed for 10 – 15 minutes. Gradually load the operation only when the pump housing temperature rises above 50°C to avoid thermal shock of hot oil on cold components.
II. Dynamic Monitoring during Operation
1. Key Parameter Control – Maintain the inlet – outlet pressure difference between 0.2 – 0.3MPa, the bearing temperature should not exceed 80°C, and the vibration value should be ≤ 5mm/s (detected by a laser vibration meter). – Monitor the motor current fluctuation in real – time. An abnormal increase may indicate impeller wear or pipeline blockage.
2. Operation Taboo Avoidance – It is strictly prohibited to continuously operate for more than 3 minutes with the outlet valve closed to prevent the medium from overheating and vaporizing. – Avoid frequent startup and shutdown of the equipment. After each shutdown, wait for more than 30 minutes before restarting to reduce motor wear.
III. Shutdown and Emergency Handling
1. Cool – down Shutdown Procedure – Before shutdown, keep the oil pump running for 30 minutes. Cut off the power supply only when the oil temperature drops below 100°C to prevent hot oil from solidifying and blocking the pipeline. – For long – term shutdown, drain the medium in the pump, purge it with nitrogen, and inject anti – rust oil. Regularly turn the shaft by hand to prevent shaft deformation.
2. Response to Sudden Situations – When a sudden increase in bearing temperature or abnormal vibration is detected, immediately switch to the standby pump and stop the machine for inspection. – In case of leakage, first close the inlet and outlet valves. Use special tools to replace the seals to avoid safety accidents caused by contact with high – temperature media.
IV. Key Points of Daily Maintenance
1. Lubrication System Management – Supplement high – temperature grease (such as ZFG – 4 type) through the grease fitting every week. The amount of grease injection should be appropriate with a small amount overflowing to prevent over – injection from causing bearing overheating.
2. Filtration System Maintenance – Clean the Y – type oil filter every month. Check the integrity of the filter screen to ensure that the impurity content does not exceed 0.1% to avoid blockage affecting the flow rate.
3. Sealing System Monitoring – Observe the leakage amount of the mechanical seal. If it exceeds 5 drops per minute, replace it in a timely manner. For the double – seal structure, also check the coking condition of the front – placed carbon fiber seal.
V. Precautions for Special Working Conditions
1. High – temperature Environment – When the medium temperature exceeds 300°C, increase the inspection frequency of the cooling system to ensure the normal circulation of the seal flushing fluid.
2. Explosion – proof Area – Select explosion – proof motors (Ex d IIB T4). Regularly check the insulation performance of electrical circuits to avoid safety accidents caused by electric sparks. By strictly following the above precautions, the operation stability of the circulation oil pump can be effectively improved, the failure rate can be reduced, the equipment service life can be extended, and reliable guarantee can be provided for the efficient operation of the industrial thermal energy system.
