Although the performance of synthetic heat conducting oil is relatively good, it is undeniable that the choice of synthetic heat conducting oil is also a principle. Now let's talk about the principle of using synthetic heat conducting oil.
1. The synthetic thermal conductive oil has high thermal conductivity, high specific heat coefficient, high thermal efficiency and good economic benefit.
2. The synthetic heat conducting oil has good thermal stability and oxidation resistance. Provide good thermal stability and oxidation resistance at the maximum allowable operating temperature, long service life. Synthetic heat conducting oil is an organic material. Whether synthetic or mineral oil, they are hydrocarbons (alkanes, naphthenes or aromatics and their derivatives). Therefore, under heating conditions, hydrocarbons will undergo pyrolysis and oxidation reactions, which will deteriorate the synthetic heat conducting oil.
The pyrolysis reaction produces low boiling point substances. Low boiling point substances can also occur polymerization (or condensation), forming polymer materials, such as colloids, resulting in increased viscosity and carbon slag, which can cause coking. The oxidation reaction produces organic acid, so the acid value of synthetic oil with thermal conductivity increases, and insoluble acid sludge will also be produced by deep oxidation. Therefore, the thermal oil furnace wall with increased viscosity of synthetic thermal conductivity oil increases, but it also increases thermal resistance and reduces thermal conductivity.
Therefore, in the selection of synthetic heat conducting oil, for mineral oil heat conducting oil, the base oil should be selected and distilled and then added with a variety of complex additives heat conducting oil. Generally speaking, synthetic oil has good stability and oxidation stability, but because of its high price, many synthetic oils still need to be imported.
3. There should be high flash point, spontaneous ignition point and boiling point. High flash point and spontaneous ignition point of heat conducting oil can avoid potential fire hazards. The liquid phase heat conducting oil has high boiling point (initial boiling point) and low boiling point content, which can ensure the safe use of liquid phase heat conducting oil. The flash point is when the heat conducting oil is heated, the volatile oil vapor mixes with the surrounding air, and the lowest temperature of the flash point when it contacts the open fire reflects the evaporation trend of the heat conducting oil.
In heat conducting oil, the effect of low boiling point is easy to evaporate, high flash point and relatively safe. Initial distillation point is the lowest temperature of distillate with the lowest boiling point in mineral oil heat conducting oil. With high initial distillation point and low boiling point component content, it is necessary to reduce steam pressure and evaporation loss, and to ensure that the highest operating temperature is liquid.
4. The synthetic heat conducting oil should have lower acid value and carbon residue. No chemical reactions and corrosion occur in the equipment and pipeline materials in the system. Thermal conductive oil is used at high temperature. The heat conducting oil heating system runs for a long time and produces chemical reactions or corrosion effects on the materials and equipment of the system. The equipment and pipelines will be scrapped in advance. The acid number is the sum of organic acids in heat conducting oil. When the acid value is high, there is little water in the oil, which will cause corrosion to the equipment. Residual carbon is a kind of colloid or asphaltene formed by polymerization (or condensation) of pyrolysis products of thermal conductive oil. High carbon content will cause coking, affect the heat transfer effect, and seriously clog equipment and pipelines.
In summary, these are the relevant selection principles of synthetic heat conducting oil. I hope you can choose synthetic heat conducting oil better after you see these principles, so that we can use them.