Company Details

Zhengzhou Chorus Lubricant Additive Co.,Ltd. [Henan,China] Business Type:Agent , Distributor/Wholesaler , Manufacturer , Service , Trade Company Main Markets: Africa , Americas , Asia , Europe , Middle East , Oceania , Worldwide , East Europe , North Europe , Other Markets Exporter:51% - 60% Certs:ISO14001, ISO9001, API, CB, CCC

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How to judge the performance of heat transfer oil, old experts all look at these "four major indicators".

2021-09-18

How to judge the performance of heat transfer oil, old experts all look at these "four major indicators".

Heat transfer oil needs to meet the following basic requirements:
High working temperature stability: resistance to oxidation and thermal cracking
Good heat transfer characteristics: high specific heat and high thermal conductivity
Low vapor pressure to prevent vapor lock/cavitation in the pump
Low safety risk: high flash point and ignition point
Low viscosity, reduce pumping loss, high viscosity index, reduce equipment load changes

Non-corrosive, non-toxic

heat conduction oil

Flash point and ignition point, the fluid must have a high flash point and high ignition point, so it has a low fire risk. The flash point is the temperature at which the oil releases enough vapor on its surface to instantly ignite when an open flame is used. The ignition point is the temperature at which vapor is quickly released to support continued combustion.

Thermal cracking, all hydrocarbon fluids will undergo thermal cracking when the oil temperature is higher than 360°C (680°F). Thermal cracking form: For light, relatively volatile products, it will cause pump cavitation and reduce the flash point of the fluid, which may cause fire hazards. For heavier and more viscous products, it will increase the resistance of the fluid to flow through the system, putting pressure on the pumps in the system.

Oxidation can lead to the formation of organic acids and sludge, which are usually compared with paint films. These by-products thicken the oil and eventually form insoluble materials, which are deposited on the heater and other surfaces of the system. The by-products of oxidation often act as catalysts for further oxidation. These coke-like deposits insulate the system and interfere with heat transfer. This requires a higher heater temperature, which can cause thermal degradation of the oil and/or system piping.

Deposits on the heat exchanger walls can interfere with heat exchange and promote further thermal cracking by creating hot spots in the system or increasing laminar flow through tube contraction. In order to prevent hot spots, the circulating pump should always be in operation, and the fluid should flow through the heater before starting. Turn off the heater before stopping the pump. After turning off the heating, the pump should run for up to 30 minutes to prevent harmful hot spots.

"Four Indexes" of Thermal Oil Performance
1. Flash point: safe
2. Acid value: low-molecular organic acids and inorganic acids are corrosive to metals, especially in the presence of water molecules, the corrosion will increase
3. Viscosity: affect the flow rate and the performance as a heat conduction carrier
4. Residual carbon: Residual carbon is a mixture of polycyclic aromatic hydrocarbons, gums, and asphaltenes; the size of the residual carbon can roughly determine the coking tendency of the heat transfer oil in high-temperature use

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