1. The thermal oil needs to be checked every 3 to 6 months and replaced every six months to one year. Whether to replace it is decided based on the actual situation.

2. Before replacing the heat transfer oil, the boiler and circulation system must be cleaned to prevent residual waste oil from contaminating the new oil and shortening the useful life of the heat transfer oil.

3. Boiler coils need to be cleaned regularly to reduce the carbon deposits produced by the thermal oil due to long-term high temperatures, maintain good thermal conductivity, ensure the normal operation of the thermal oil heater, and extend the service life of the thermal oil and equipment.

1. Water-based Cleaning Method: This involves draining the waste oil from the thermal oil furnace system and using compressed air to blow away any remaining oil. Then, a water rinse is added to wash the remaining waste oil to a low-level tank for oil-water separation. Once this pre-rinse is completed, the entire system is filled with a cleaning agent. The circulating pump is activated to heat and circulate the cleaning solution. Through a chemical reaction, the specialized solution penetrates, dissolves, and removes carbon deposits and waste oil residues from the thermal oil furnace system. After confirming the cleaning standards are met, the system is flushed with clean water, removing the decomposed waste oil and residue from the system, leaving it similar to new equipment. This cleaning method requires technical expertise and high-quality cleaning agents.

2. Solvent-based Cleaning Method: After draining the waste oil from the thermal oil furnace system and blowing it clean with compressed air, there may still be a residual 30-40% waste oil left. Then, a solvent is added until the system is fully circulated. The circulation pump is activated for a certain period before releasing the solvent mixture waste liquid. If some residue remains, compressed air is used to blow out the waste oil-solvent mixture. This method is simpler, but when new thermal oil is introduced, it quickly deteriorates, with residues exceeding ten times the waste levels compared to new thermal oil.

3. Online Cleaning Method: Calculating the total amount of thermal oil in the system, a 5-10% solvent cleaning agent is added. Initially, an equal amount of waste thermal oil is released, followed by the addition of the same quantity of online cleaning agent. After circulating for a period or 1-2 days, the mixture is discharged, and the thermal oil furnace system is blown with compressed air to remove waste oil and solvent cleaning agent residues. This method is straightforward and inexpensive but may result in poor cleaning. Particularly during the introduction of new thermal oil, it might cause severe damage and leave significant amounts of waste liquid, rendering the new thermal oil nearly useless."