1. What is Heat Transfer Oil?
Heat Transfer Oil (also known as Thermal Oil, Heating Oil, Heat Carrier Oil, Thermal Conductive Oil, or Insulating Oil) is a type of compound formulated from 85% premium base oil and 15% of a specialized additive system specifically designed for heat transfer systems. The oil possesses excellent thermal conductivity, high thermal stability, a high viscosity index, and a high flash point, enabling the heat transfer system or heat exchanger to operate accurately at the required temperature while ensuring absolute safety for the entire system.
2. Applications
Widely used in heat transfer systems across various industrial sectors such as metal processing, food production, chemical plants, textile manufacturing, woodworking, paper production, plastic industry, cement manufacturing, asphalt melting, and oil-based cooling equipment. Additionally, it is also used for heat transfer in certain domestic equipment such as porridge cookers, heating systems, drying systems, boilers, etc.
3. Requirements for Heat Transfer Oil
To ensure performance and safety, heat transfer oil must meet several basic requirements as follows:
Thermal Stability:
The oil must withstand high temperatures without decomposing or undergoing chemical changes.
High thermal stability helps prevent sludge formation and extends the oil’s service life.
Appropriate Viscosity:
The oil’s viscosity should be low enough for easy pumping and circulation within the system, yet high enough to provide lubrication for contact surfaces.
Heat Transfer Capability:
The oil must possess excellent thermal conductivity to effectively transfer heat from the source to the point of use.
High Boiling Point:
A high boiling point is necessary to prevent boiling and foaming during high-temperature operations.
Oxidation Resistance:
The oil should resist oxidation to avoid degradation when exposed to air at high temperatures.
Non-toxic and Environmentally Safe:
The oil should not contain harmful components to ensure operator safety and environmental protection.
Non-Flammable:
The oil should have a high flash point to reduce the risk of fire or explosion within the system.
Water Separation Ability:
The oil must have good demulsifying properties to prevent steam formation and corrosion within the system
4. Classification of Heat Transfer Oil
Currently, there are two main types of heat transfer oil on the market:
Mineral-Based Heat Transfer Oil:
This type is formulated from approximately 85% high-grade paraffinic base oil and 15% of a specialized additive system for various heat transfer applications. It offers good thermal conductivity, high thermal stability, a high viscosity index, and a high flash point. These features ensure the proper functioning of heat transfer systems or heat exchangers and provide absolute safety for thermal oil heating systems. Due to its lower cost, mineral-based oil holds over 70% market share. Its continuous operating temperature typically ranges from 280°C to 300°C.
Synthetic Heat Transfer Oil:
This oil is derived from branched alkylbenzenes and is widely used in both industrial and residential heat transfer systems. It is suitable for use within the temperature range of -20°C to 330°C and is ideal for closed-loop circulation systems with heat transfer pumps. Especially notable is its high thermal conductivity, which helps reduce fuel consumption in electric or coal-fired heating furnaces.
5. Notes When Using Heat Transfer Oil
To ensure stable operation of the system and equipment, users should keep in mind the following precautions:
The heat transfer system—whether new or used—should be thoroughly cleaned before being put into operation. If necessary, an alkaline-based chemical cleaner should be used. These cleaning agents are typically circulated with hot water throughout the system to remove deposits.
Periodic replacement of heat transfer oil is essential to protect and maintain the system’s performance.
Select a heat transfer oil with a viscosity suitable for the system’s engine, ensuring it meets the required heat transfer efficiency, oxidation resistance, and thermal conductivity.
Regular oil testing is crucial to monitor viscosity, acid number, flash point, and insoluble content. It is recommended to take a sample within a few days after system startup and subsequently every six months.
Purchase heat transfer oil from reputable and quality-assured suppliers to avoid counterfeit or substandard products and to receive accurate and helpful technical support.
