Original issue with the heat transfer oil.

Asking the technical staff at your company will definitely give you a satisfactory answer.

This post was last edited by Heat Transfer Oil on 2012-11-29 at 16:09. Knowledge about heat transfer oil: There are many types of heat transfer oil, and the software can only list some of the most well-known products from prominent companies. When making calculations, one can choose the appropriate heat transfer oil based on its boiling point indicated as Tb. In actual purchases, most manufacturers in China also follow the characteristics of these typical products. Below is a brief introduction to the classification of heat transfer oils, which will help everyone choose the appropriate type of heat transfer oil. Structurally, heat transfer oils can be divided into two main categories: synthetic and mineral oil-based. Synthetic heat transfer oils, also known as thermal conductive fluids, are produced through organic synthesis processes using petrochemical or chemical products as raw materials. They are pure or relatively pure chemicals characterized by good stability, a long service life, and renewability; however, their price is relatively high. Mineral oil-based heat transfer oil, also known as thermal conductive oil, is made from certain fractions of petroleum through processing and formulation; it is a mixture of various alkane components. Mineral oil-based heat transfer oils have a wide range of available raw materials, a simple production process, and low costs; however, their thermal stability and oxidation resistance are relatively poor due to the characteristics of their multi-component composition. I. Synthetic type ① Biphenyl-biphenyl ether. It consists of 73.5% diphenyl ether and 26.5% diphenyl, forming an azeotropic system with a boiling point of 257° and a maximum operating temperature of 400°. This is a product developed by the American company Dow in the 1930s; it is also the earliest and longest-used product of its kind. Its advantages include good thermal stability and low tendency to form carbon deposits, while its disadvantages are strong permeability, an unpleasant odor, and carcinogenic properties. Due to environmental regulations, there are strong calls to ban it, but it is still widely used to a certain extent because of its excellent performance. The main brands include: 1) Dowtherm A from the American company Dow Chemical, and Therminol VP-1 from the American company Monsanto. 2) Hydrogenated terphenyls. It is a mixture of ortho-, meta-, and para-hydrotriphenyl compounds, with the para proportion not exceeding 30%, otherwise precipitation occurs. Operating temperature: -10 to 340°. Currently, hydrogenated triphenyl is responsible for the majority of market share abroad, serving as the preferred heat transfer fluid for many heat transfer systems. It features good stability at high temperatures and low vapor pressure, but its flow properties are slightly poor at low temperatures. Hydrotriphenylbenzene offers considerable flexibility in the production process, allowing the degree of hydrogenation to be selected depending on the operating temperature. The main brands include: 1) Therminol 66 from the American company Mansanto, and Therm S 900 from the Japanese company Nippon Steel. ③Benzyltoluene and dibenzyltoluene. Both are heat transfer fluids with good performance; monobenzyltoluene can be used at temperatures ranging from -80 to 350°C, while dibenzyltoluene can be used in the range of -30 to 350°C. However, the boiling point of monobenzyltoluene is 280°C, so it must be used as a gas-phase heat transfer fluid at temperatures above 300°C. Dibenzyltoluene has a boiling point of 355–400° and can be used at high temperatures of up to 350°C for extended periods. The main brands include: Hills from Germany’s Marlotherms SH, and Neosk-oil1400 from Japan’s SSKEN Chemical Engineering Co., Ltd. / R. f8 n* k! S* R1 U) b" h1 ] ④Alkylnaphthalene. Mainly methylnaphthalene, dimethylnaphthalene, isopropylnaphthalene, etc. It can be used in a temperature range of -30 to 300°C. It features low toxicity, low corrosivity, and good thermal conductivity. It also has a low freezing point, making it easy to transport; hence it is suitable for cold regions. However, its high-temperature stability is slightly inferior to that of the other three types. II. Mineral oil type: Generally composed of heavy petroleum fractions, it features safety, low toxicity, and low cost. However, its operating temperature is relatively low; compared to synthetic heat transfer fluids, it has poor thermal stability at high temperatures and is prone to oxidation and cracking. Generally, additives such as antioxidants need to be added. The raw materials for producing mineral oil-based heat transfer oils include high-boiling-point residue, catalytic cracking diesel, furfural or ester-refining solvent-extracted lubricating oils, and pyrolysis residue obtained from the steam cracking of hydrocarbons to produce olefins. These crude oils contain high-boiling-point aromatics; after hydrorefining to remove impurities and polycyclic aromatics, the appropriate fractions are distilled to produce heat transfer oil. Common mineral-based heat transfer oil products available on the market include: Mobil Oil Corp.’s Mobihherm series, Shell Oil Company’s Shell Themia Oil B and Shell Thermia Oil E, Exxon Corporation’s Caloria HT43, 13 Ben Dong Co. and Soken Chemical Company’s Neosk Oil L400, BP’s Tran~al, Mobil Oil Corp.’s Mobil Therm 600, and BP’s Transcal LT. Domestic mineral-based heat transfer oils have developed rapidly, and their performance is now comparable to that of foreign products; however, synthetic heat transfer fluids with a higher level of technical complexity still lag behind those available abroad. Most of the domestic petrochemical, chemical fiber, and polyester industries use imported Dow oil or hydrogenated triphenyls.

The person upstairs has already explained it to you in detail. May I ask which company the original poster works at? Schulz heat transfer oil is a highly complex field that involves many aspects of thermodynamics. Or you can check Baidu Wenku; it also contains detailed information on the classification of Schulz heat transfer oils, their operating temperatures, usage conditions, and key parameters.

1. Alkylbenzene-type (benzene-ring type) heat transfer oils: These types of heat transfer oils are compounds in which a benzene ring is attached to alkane side chains; they are products resulting from the combination of short-chain alkyl groups (including methyl, ethyl, and isopropyl) with the benzene ring. Its boiling point is between 170–180°C, and its freezing point is below -80°C; therefore, it can be used as an antifreeze. The advantage of such products is that they do not tend to form precipitates within their applicable range, with compounds containing isopropyl side chains being particularly good for this purpose. 2. Alkylnaphthalene-type heat transfer oils: These types of heat transfer oils are compounds in which alkyl side chains are attached to benzene rings. The side chains attached to it are generally methyl, dimethyl, isopropyl, etc.; the type and number of these attached side chains determine the properties of the compound. Alkylnaphthalenes with a methyl group attached to the side chain are used in gas-phase heating systems operating in the range of 240–280°C. 3. Alkylbiphenyl-type heat transfer oils: This type of heat transfer oil consists of compounds in which alkyl side chains are attached to the biphenyl ring. It is composed of short-chain alkyl groups (ethyl, isopropyl) combined with biphenyl rings, and the type and quantity of alkyl groups determine its properties. The greater the number of alkyl groups, the worse its thermal stability. Among such products, heat transfer oils synthesized from the meta and para isomers of isopropyl along with biphenyl offer the best quality; they have a boiling point of >330°C and good thermal stability, making them ideal for use in the 300–340°C range. 4. Biphenyl and biphenyl ether low-melting mixture-type heat transfer oil: This type of heat transfer oil is a low-melting mixture of biphenyl and biphenyl ether, composed of 26.5% biphenyl and 73.5% biphenyl ether. Its melting point is 12°C. The first synthetic aromatic heat transfer oil used in the world was Dowtherm, which is characterized by good thermal stability and a high operating temperature of 400°C. Such products have the best heat resistance among organic heat carriers because there are no alkyl side chains attached to the benzene ring. This low-freezing mixture with a freezing point of 12.3°C is economical to use at room temperature, as its boiling temperature lies within the range of 256–258°C. This is because the melting points of both substances are relatively high (biphenyl is

Thank you all for your help, but none of you addressed the key points. I need to know the chemical formulas of mineral-based and alkylbenzene types, as well as the specific advantages of alkylbenzene over mineral-based ones

Alkylbenzenes naturally have alkyl groups attached to the benzene ring, whereas those of mineral origin are mostly straight-chain alkanes or cycloalkanes attached to straight chains. Comparing the two, alkylbenzenes have a more stable structure and poor thermal cracking tendency, whereas straight-chain compounds are prone to breaking down into smaller alkane molecules, which can easily reach their ignition point and cause tube explosion.

Baidu Baike has a very comprehensive overview of chemical molecules: http://baike.baidu.com/view/1264053.htm I’ve pasted the URL for you

The regeneration of heat transfer oil takes place in two ways: 1) on-line regeneration (which can be carried out without shutting down the furnace or stopping production), and 2) off-line regeneration. For customers who use large amounts of heat transfer oil, this regeneration process is very cost-effective. (TEL: 1811 8269 273) It is possible to purify heat transfer oil that does not meet the standards through physical methods, such as vacuum distillation, thereby removing the heavier components from the oil. As a result, the regenerated oil can reach standards similar to those of new oil. Furthermore, online regeneration eliminates the cost of cleaning the boiler system, thereby saving businesses a significant amount of money in the long run