What Does the Daily Maintenance of Heat Exchangers Include?
The operation cycle of the heat exchanger should be consistent with the production cycle of the production device. In order to ensure the normal operation of the heat exchange equipment and meet the requirements of the production device, in addition to regular inspection and supervision, daily maintenance and repair are also indispensable.
Special care should be taken to prevent fluctuations in temperature and pressure in daily operations. First, the pressure should be stable, and overpressure operation is never allowed.
Leakage problems are most likely to occur when starting and stopping line sweeping. If the floating head of the heat exchanger is prone to leaks, the outer closure head of the floating head should be opened first to check the pressure test from the pipe side when repairing. Sometimes the floating head bolts are not tight. This is due to the plastic deformation caused by long-term heating of the bolt.The measures usually taken are to test the pressure with steam after the tube bundle hydraulic pressure test is passed. When the temperature rises to 150~170℃, the bolts can be tightened again, so that the floating head has better sealing.Most of the heat exchanger failures are caused by the tubes. The perforation of the tubes due to corrosion should be replaced in time. If only the individual tubes are damaged and it is more difficult to replace, the ends of the bad tubes can be blocked with pipe plugs. The hardness of the pipe plug material should not exceed that of the pipe material, and the total number of blocked pipes should not exceed 10% of that of pipes in the pipe pass. Heat exchangers that are prone to scaling should be cleaned in time to avoid affecting the heat transfer efficiency.
1. During the steam purging of the installation system, the purging of the coated cold exchange equipment should be avoided as much as possible. When the process is determined to be unavoidable, the purge temperature should be strictly controlled at no more than 200 degrees Celsius to avoid damage to the coating.
2. During the start and stop of the device, the heat exchanger should be slowly heated and cooled to avoid excessive pressure difference and thermal shock. At the same time, it should follow the "heat first and then cool" during the shutdown, that is, first removing the heat medium and then the cold medium; "Cold first, then hot" when starting work, that is, receiving cold medium, then heat medium.
3. Before starting work, make sure that the threaded locking ring heat exchanger system is smooth and avoid over-pressure on one side of the tube sheet.
4. Check the operating parameters of the heat exchange equipment carefully, and prohibit over-temperature and over-pressure. For heat exchangers designed with differential pressure, the specified differential pressure shall not be exceeded during operation.
5. The operator should strictly abide by the safety operation regulations, conducting regular patrol inspections on the heat exchange equipment, checking the foundation support for stability and equipment leakage, etc.
6. The temperature and pressure drop of the medium in the pipe and the tube pass should be checked frequently to analyze the leakage and scaling of the heat exchanger. When the pressure drop increases and the heat transfer coefficient decreases beyond a certain value, an effective method should be selected for cleaning according to the structure of the medium and the heat exchanger.
7. The vibration of the heat exchanger should be checked frequently.
8. During operation, the temperature of cold-swappable equipment with anti-corrosion coating should be strictly controlled to avoid coating damage.
9. Keep the insulation layer intact.
Special care should be taken to prevent fluctuations in temperature and pressure in daily operations. First, the pressure should be stable, and overpressure operation is never allowed.
Leakage problems are most likely to occur when starting and stopping line sweeping. If the floating head of the heat exchanger is prone to leaks, the outer closure head of the floating head should be opened first to check the pressure test from the pipe side when repairing. Sometimes the floating head bolts are not tight. This is due to the plastic deformation caused by long-term heating of the bolt.The measures usually taken are to test the pressure with steam after the tube bundle hydraulic pressure test is passed. When the temperature rises to 150~170℃, the bolts can be tightened again, so that the floating head has better sealing.Most of the heat exchanger failures are caused by the tubes. The perforation of the tubes due to corrosion should be replaced in time. If only the individual tubes are damaged and it is more difficult to replace, the ends of the bad tubes can be blocked with pipe plugs. The hardness of the pipe plug material should not exceed that of the pipe material, and the total number of blocked pipes should not exceed 10% of that of pipes in the pipe pass. Heat exchangers that are prone to scaling should be cleaned in time to avoid affecting the heat transfer efficiency.
1. During the steam purging of the installation system, the purging of the coated cold exchange equipment should be avoided as much as possible. When the process is determined to be unavoidable, the purge temperature should be strictly controlled at no more than 200 degrees Celsius to avoid damage to the coating.
2. During the start and stop of the device, the heat exchanger should be slowly heated and cooled to avoid excessive pressure difference and thermal shock. At the same time, it should follow the "heat first and then cool" during the shutdown, that is, first removing the heat medium and then the cold medium; "Cold first, then hot" when starting work, that is, receiving cold medium, then heat medium.
3. Before starting work, make sure that the threaded locking ring heat exchanger system is smooth and avoid over-pressure on one side of the tube sheet.
4. Check the operating parameters of the heat exchange equipment carefully, and prohibit over-temperature and over-pressure. For heat exchangers designed with differential pressure, the specified differential pressure shall not be exceeded during operation.
5. The operator should strictly abide by the safety operation regulations, conducting regular patrol inspections on the heat exchange equipment, checking the foundation support for stability and equipment leakage, etc.
6. The temperature and pressure drop of the medium in the pipe and the tube pass should be checked frequently to analyze the leakage and scaling of the heat exchanger. When the pressure drop increases and the heat transfer coefficient decreases beyond a certain value, an effective method should be selected for cleaning according to the structure of the medium and the heat exchanger.
7. The vibration of the heat exchanger should be checked frequently.
8. During operation, the temperature of cold-swappable equipment with anti-corrosion coating should be strictly controlled to avoid coating damage.
9. Keep the insulation layer intact.
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