Luoyang Wo Hong Petrochemical Equipment: Introduction of Winter Operation Adjustment and Antifreeze Supporting Services for Recovery Unit

The solvent recovery unit is prone to several types of concentration problems in winter: condensate freezing and blocking in pipelines and low points, drift of control instrument readings, and different load of condensation section from summer, resulting in parameters no longer adapting. These conditions are generally exposed after cooling down, and they are often temporarily shut down when the device alarms or the condensate cannot be discharged. LuoyangWohong PetrochemicalThe equipment provides winter operation adjustment and anti-freezing supporting services for the recovery device. The core work is to sort out the easily frozen parts before cooling down and check the parameters again according to the low temperature working conditions.

Common winter problems and causes

The first category is frozen. The low point of the pipeline, the drain valve and the interface of the condensate tank level gauge are easy to freeze first as long as there is liquid accumulation and the heat preservation is not in place. The second category is the instrument drift, part of the transmitter in the low temperature environment reading deviation becomes larger, resulting in the control loop in the wrong value adjustment. The third category is that the parameters are no longer adapted: after the ambient temperature drops, the actual load of the condensation section becomes smaller. If the temperature level and cooling capacity distribution are still set according to summer, the system will operate in the low-efficiency area. The fourth category is the efficiency change of air-cooled equipment, and the relationship between fan speed and ambient temperature needs to be reconfirmed.

Several drop points of antifreeze matching

1. Comb all low-point drainage positions, and confirm whether the heat preservation or heat tracing is effective one by one.
2. The freezing parts such as the liquid level gauge of the condensate tank and the sampling port shall be insulated separately.
3. Confirm protective measures for outdoor instrument and sampling pipeline according to environmental conditions
4. Retain the manual drain valve as an alternate means of operation to prevent the automatic valve from freezing and being unable to operate.
5. Write the winter inspection items and frequency into the post record form, without verbal reminders.

How to adjust the operating parameters

Comparison of winter and summer operation

Comparison item	Summer operation	Winter operation concerns
Condensation load	High ambient temperature and heavy load	The load drops and the cold quantity needs to be redistributed.
Freezing risk	Basically None	Low point effusion and instrument interface are easy to freeze
Air-cooled equipment	Focus on heat dissipation capacity	Focus on rotational speed and antifreeze protection
Key Inspection Points	Temperature and pressure trends	Added drain and heat preservation inspection

The principle of low temperature seasonal adjustment is to follow the actual load. Condensation temperature level, cold energy distribution and fan operation strategy should be re-checked according to the current air source conditions, instead of using summer settings. After adjustment, it is recommended to continuously record for a period of time, judge whether it is stable with the condensate outlet temperature and condensate volume trend, and then solidify into the operation regulations after confirmation. If there is automatic adjustment in the control loop, it is necessary to confirm whether it is still working in the effective range under low temperature working conditions, and switch to manual operation if necessary and check periodically.

Service Implementation Mode

In the implementation, the operation records and pipeline drawings of the device shall be retrieved first, and the frozen parts and heat preservation status shall be checked on site, and then the list of anti-freezing measures and parameter adjustment suggestions shall be determined in combination with the local climate conditions. It can be completed centrally before cooling, or it can be implemented in batches according to the workshop maintenance window. Written records shall be provided after the adjustment is completed for the convenience of post personnel in subsequent operation.

Summary

Most of the winter problems are not equipment failures, but preparations are not completed before the temperature drops. Sorting out the easy freezing points and checking the parameters according to the low temperature working conditions, the device can usually survive the winter smoothly without waiting for shutdown.