Boiling point of heat transfer oil

What type of heat transfer oil are you asking about, and what is it used for? Physical properties of heat transfer oil: A range of physical properties of heat transfer oil, such as viscosity, vapor pressure, boiling range, initial boiling point, and flow point, are related to the performance of the oil. Viscosity is directly related to heat transfer efficiency; the lower the viscosity of the oil, the faster it can flow, and thus the higher the heat transfer efficiency. A liquid compound has a certain boiling point under a given atmosphere. Typically, heat transfer oil is a mixture, and the boiling points of its various components are not identical. The range between the lowest and highest boiling points among these oil components is referred to as the boiling range. The higher the boiling range, the higher the maximum operating temperature of the oil. Whether an oil is prone to catching fire can be determined by its vapor pressure, flash point, ignition point, and auto-ignition temperature. If oil easily volatilizes into gas, it is prone to catching fire. The flash point, ignition point, autoignition point are also related to the volatility of oil. The amount of oil vaporization can be expressed by the oil’s vapor pressure. As the temperature rises, the amount of oil that vaporizes increases, and the vapor pressure rises accordingly. A certain oil, at a specific temperature, has a constant vapor pressure. The flash point is the lowest temperature at which a mixture of oil vapor and air emits a brief flash of flame when brought near a flame. When the temperature of a certain oil rises to a specific level and ignition occurs, resulting in a flame that does not go out, the lowest temperature at which this phenomenon occurs is known as the ignition point. When the oil temperature rises to a certain level, it can catch fire spontaneously upon contact with air without the need for an ignition source. The lowest oil temperature at which spontaneous combustion occurs is known as the autoignition point. If the oil has a low vapor pressure, its flash point, ignition point, and autoignition point are high; in such cases, the oil is less likely to cause fires. Typically, the operating temperature of oil is above its flash point, which requires that the oil not come into direct contact with open flames or sparks; however, this operating temperature must be below the oil’s auto-ignition point. The safety of oil is also related to its operating temperature and its initial boiling point. Under certain conditions, the distillation temperature at the moment the first drop of distillate emerges from the end of the condenser is called the initial boiling point; this is related to the low-boiling-point fractions in the oil. For both safety and operating temperature considerations, a high initial boiling point is desirable. The so-called flow point refers to the lowest oil temperature at which the oil can flow. Oil with a low flow point remains fluid even in the severe cold of the north; otherwise, it will make it difficult to start the oil furnace. What is the relationship between the physical properties of oil and its molecular structure? The physical properties of many oils are directly related to the intermolecular forces; if these forces are weak, the liquid evaporates easily, resulting in a high vapor pressure as well as lower boiling points and initial distillation points. Conversely, when the intermolecular forces decrease due to reduced attraction, the viscosity of the oil also decreases, and the boiling point drops as well. Where does intermolecular attraction come from? Why is there a difference in size? Ultimately, this force is an electrostatic attraction; there is a force between the positive end of one molecule and the negative end of another molecule, and the greater the charge on these positive and negative ends, the stronger the attraction. Intermolecular attractions can be divided into the following types: (1) attractions between ions. (2) Dipole-dipole attraction. (3) Hydrogen bonds. (4) Van der Waals forces: In alkanes, the boiling point increases by approximately 20–30°C for each additional carbon atom. Therefore, among hydrocarbon-based heat transfer oils of the same type, as the molecular weight increases, the intermolecular forces become stronger; as a result, the vapor pressure of the oil decreases while its flash point and boiling point increase, which is beneficial for the performance of the heat transfer oil. However, the viscosity and flow point of oil increase as molecular attraction increases, which is detrimental to the performance of heat transfer oils. Therefore, we cannot choose a base oil that has low vapor pressure, high boiling point and flash point, while at the same time having low viscosity and flow point; when selecting a base oil, we must find a balance among these physical properties.

There are many types of heat transfer oils, and their boiling points vary depending on the type. For example, here are two such heat transfer oils: 1) Biphenyl-biphenyl ether mixture (usable in both gas and liquid phases); 2) Hydrogenated triphenyl (high-temperature liquid heat transfer oil); 3) Medium-temperature biphenyl; 4) Low-temperature biphenyl (usable in both gas and liquid phases); 5) 320 heat transfer oil (high-temperature liquid heat transfer oil). The biphenyl-biphenyl ether mixture (LD-400) is made by using imported biphenyl from Japan and high-quality domestic biphenyl ether as raw materials, which are then mixed in precise proportions and refined further. The biphenyl-biphenyl ether mixture is a eutectic mixture prepared by combining biphenyl and biphenyl ether in a mass ratio of 26.5:73.5. This product is non-corrosive and possesses good thermal stability; it can be used for a long time within the operating temperature range of 12–400°C. It also has excellent safety properties, with a low saturated vapor pressure at high temperatures, allowing it to be used for both gas-phase and liquid-phase heating. It can be used in combination with similar products such as Thermino1-vp-1 from the United States, Dowtherm-A, Therm-S-300 from Japan, and Diphy1 from West Germany. 　　Hydrotriphenyl (LD-340) is obtained by the partial hydrogenation of a mixture of o-, m-, and p-triphenyls in different proportions (with a saturation degree of 40%). Average molecular weight: 252. Appearance: slightly yellow transparent oily liquid. Freezing point: -30°C. Low permeability at high temperatures; can be used in liquid phase at 345°C. It is currently the highest quality liquid high-temperature heat transfer oil available. It is a product similar to American Therminol-66 and Dowtherm-RP, French Gilotherm-TH, and Japanese Therm-s-900 heat transfer oils, and can be used in combination with them. 　　Medium-temperature biphenyl heat transfer oil (LD-244) has a boiling point of 244 degrees and is an imported product. 　　Low-temperature biphenyl heat transfer oil (LD-181) has a boiling point of 181 degrees and is an imported product.

To be clear, first of all, which type of heat transfer oil are you using?； What is the operating temperature? Is it mineral or synthetic?

Check out the relevant information: http://bbs.hcbbs.com/viewthread.php?tid=97979. Additionally, the main components of heat transfer oil are biphenyl and phenyl ether; the proportions vary depending on the operating temperature. For example, it may consist of 26.5% wt of biphenyl and 73.5% wt of phenyl ether. The properties of biphenyl are as follows: Chinese name: Biphenyl; Molecular formula: C12H10; Hazard category: –; Other names: Phenylbenzene; Molecular weight: 154.21; Hazardous goods code: –; English name: Biphenyl; UN number: –; CAS number: 92-52-4. Appearance and characteristics: Colorless or pale yellow, flaky crystals with a slightly sweet odor. Solubility: Insoluble in water, but soluble in ethanol, ether, and other organic solvents. Melting point: 69.71°C; Boiling point: 254.25°C; Heat of combustion: No data available; Relative density (air = 1): 5.80; Relative density (water = 1): 1.04; Saturated vapor pressure: 0.66 kPa (101.8°C); Critical temperature: No data available; Critical pressure: No data available; Contraindications: Strong oxidizing agents; Stability: Stable; Polymerization risk: Does not polymerize; Flammability: Flammable; Ignition temperature: 540°C; Fire hazard category: Class C; Explosive limit: Upper limit 5.8% (155°C), lower limit 0.6% (111°C); Flash point: 113°C; Combustion (decomposition) products: Carbon monoxide, carbon dioxide, and black smoke of unknown composition. The properties of phenyl ether are as follows: Chinese name: Phenyl ether; Molecular formula: C12H10O; Hazard category: –; Other names: Phenyl ethere; Molecular weight: 170.22; Hazardous goods code: –; English name: Phenyl ether; UN number: –; CAS number: 101-84-8. Appearance and characteristics: Colorless crystals or liquid with a distinctive odor; low volatility. Solubility: Insoluble in water, but miscible with most organic solvents such as alcohols and ethers. Melting point: 28°C; Boiling point: 257°C; Heat of combustion: No data available; Relative density (air = 1): 5.86; Relative density (water = 1): 1.07 (20°C); Saturated vapor pressure: 0.0013 kPa (°C); Critical temperature: No data available; Critical pressure: No data available; Contraindications: Strong oxidizing agents; Stability: Stable; Polymerization risk: Does not polymerize; Flammability: Flammable; Ignition temperature: 620°C; Fire hazard category: Class C; Explosive limit: 0.8–1.5%; Flash point: 115°C; Combustion (decomposition) products: Carbon monoxide, carbon dioxide

I’ve learned about it. My company has just designed a reboiler whose heating medium is heat transfer oil; however, the medium was chosen based on the requirements of the client

Which companies in China are currently producing or selling American Therminol-66? I asked for advice!