Ask an expert about heat transfer fluids

1.At present, there is no national standard for heat transfer oil industry in China, and there is an industry standard SH T 0677-1999 (Petrochemical Industry Standard of the People's Republic of China - Heat Transfer Fluid), which was implemented on April 1, 2000.

2.At present, many people in China have misunderstandings in this regard: they think that how many sizes of heat transfer oil can be used.

The maximum use temperature of a product is obtained as above, how many numbers are different in the distillation (physical) process of different products within the enterprise, which is not equal to the temperature that can be used (such as the domestic chemical fiber industry use temperature of about 300 Why not use domestic 350 heat transfer oil, and use imported goods, not do you want to use ,--).

If you just want standards, each heat transfer oil company enterprise standards are different, you can refer to the industry standard SH T 0677-1999 (link, most of the requirements are only reports, there is no more detailed standard, you can say no).

In total, there are four indicators: kinematic viscosity, carbon residue, flash point, and acid number. Among them, there are national standards for kinematic viscosity, flash point and acid number, which are GB 265-88, GB 3536-83 and GB 264-83

Carbon residue is only the industry standard, i.e. SH T 0170-92

If you want to judge whether the quality of the new oil meets your requirements, you can refer to SH T0677-1999, the key is to see the test results of thermal stability, whether it meets your use temperature requirements.

If you want to determine whether the heat transfer oil in use can continue to be used safely, you can refer to the "Safety Technical Supervision Regulations and Relevant Terms and Regulations for Organic Heat Carrier Furnaces", which generally measure the four indicators of flash point, viscosity, acid value and residual carbon.

Specific heat capacity is the amount of heat required to increase the temperature of a certain amount of homogeneous substance by 1k in the absence of phase change and chemical change.

Using the concept of specific heat capacity, it is possible to deduce a molar heat capacity that represents the amount of heat required to raise 1 k of a mol substance. The molar heat capacity cp under isobaric conditions is called the constant pressure molar heat capacity. The molar heat capacity CV under isochoric conditions is called the constant volume molar heat capacity.

The relationship between the constant pressure molar heat capacity and temperature is usually correlated as a polynomial.

As an industrial oil heat transfer medium, it has the following characteristics: it can greatly reduce the operating pressure and safety requirements of the high-temperature heating system, and improve the reliability of the system and equipment; It can reduce the complexity of systems and operations; The initial investment and operating costs of the heating system can be reduced.

The unit of specific heat capacity is the composite unit.

In the International System of Units, the principal units of energy, work, and heat are unified as joules, and the principal units of temperature are Kelvin, so the SI unit of specific heat capacity is j·kg-1·k-1, which is read as "joules [ears] per kilogram of kelvin [Ervin]". The SI unit or j (kg·) is read as "joules per kilogram Celsius."

Common units: j (kg· )j (g· )kj (kg· )cal (kg· )kcal (kg· )etc. Note that Celsius and Kelvin differ only in the representation of the temperature scale, and are equivalent in the sense of the magnitude of the temperature difference, so that and k in these units can be arbitrarily substituted with each other.

For example, "joules per kilogram Celsius" and "joules per kilogram open" are equivalent.

Thermal conductive oil (English name is Thermal Conductive Oil) is the former name of "thermal carrier oil" in GB T4016-1983 "Terminology of Petroleum Products", which is used to indirectly transfer heat A special oil with good thermal stability. Because of its uniform heating, accurate temperature control, high temperature under low vapor pressure, good heat transfer effect, energy saving, convenient transportation and operation, etc., it has been widely used in various occasions in recent years, and its use and dosage are increasing.

As an industrial oil heat transfer medium, it has the following characteristics: it can greatly reduce the operating pressure and safety requirements of the high-temperature heating system, and improve the reliability of the system and equipment; It can reduce the complexity of systems and operations; The initial investment and operating costs of the heating system can be reduced. In the case of a system leak caused by an accident, there is a possibility that combustion may occur when the heat transfer fluid meets an open flame, which is a problem with the heat transfer oil system compared to the water vapor system.

However, in the absence of leakage, the heat transfer oil system is safer to operate than the water and steam system because it operates at low pressure. There are seven elements of heat transfer oil detection, because heat transfer oil has a series of physical properties, such as viscosity, vapor pressure, boiling range, initial distillation point, flash point, ignition point, flow point, etc. The purpose of regular in-service inspections is to understand changes in the intrinsic quality of the oil and to discover system design, operation management, and heat conduction.

Heat transfer fluids are chemically stable and do not burn as easily as light oils. From the perspective of use and safety, its main characteristics are:

1.In the allowable temperature range, the thermal stability is good, the coking is less, and the service life is long.

2.Within the allowable temperature range, the thermal conductivity, fluidity and pumpability performance are good.

3.Low toxicity, tasteless, does not corrode equipment, and has little impact on the environment.

4.The freezing point is lower, the boiling point is higher, and the content of low-boiling point components is less. Within the allowable temperature range, the vapor pressure is not high, and the evaporation loss is small.

5.When the temperature is higher than 70, it will be strongly oxidized in contact with the air, and its heated working system needs to be sealed, and only allow it to contact with the air at a temperature below 70.

6.After heating, the volume expands significantly, and the expansion rate is much greater than that of water. The temperature rise is 100, and the volume expansion rate can reach 8% 10%.

7.Cracking or condensation occurs when overheated, and coking or carbon deposits occur in vessels and pipes.

8.When mixed with water or low-boiling components, the vapor pressure increases significantly when heated.

9.The flash point, ignition point and spontaneous ignition point are all high, and it will not catch fire and burn at the allowable temperature and in a closed state.

Specific heat capacity, pronounced bǐ rè róng, and specific heat capacity in English, refers to the amount of heat required to increase the temperature of a certain amount of homogeneous substance by 1k in the absence of phase change and chemical change.

Using the concept of specific heat capacity, it is possible to deduce a molar heat capacity that represents the amount of heat required to raise 1 k of a mol of substance. And the molar heat capacity cp under isobaric conditions is called constant pressure molar heat capacity. The molar heat capacity CV under isochoric conditions is called the constant volume molar heat capacity.

The relationship between the constant pressure molar heat capacity and temperature is usually correlated as a polynomial.

1. The specific heat capacity is larger.

2. Good fluidity at high temperature.

3. The boiling point is high and the volatilization is small, which will not cause the system to reduce the amount of heat conduction medium due to the volatilization of the heat transfer medium.

The oil heater is to directly insert the electric heater into the organic carrier (heat transfer oil) for direct heating, and through the forced liquid phase circulation of the high-temperature oil pump, the heated heat transfer oil is transported to the heating equipment, and then returned to the hot oil furnace by the oil outlet of the heating equipment to form a complete circulating heating system.

The heat conduction oil heater is produced and transmitted by the electric heating element immersed in the heat transfer oil, with the heat transfer oil as the medium, the circulation pump is used to force the heat transfer oil to carry out liquid phase circulation, and the heat is transferred to one or more heating equipment, after the heat equipment is unloaded, it is re-passed through the circulation pump, returned to the heater, and then absorbed the heat and transferred to the heating equipment, so that the continuous transmission of heat is realized, and the temperature of the heated object is increased to meet the process requirements of heating.

Heat transfer oil, formerly known as "heat carrier oil", is a special oil with good thermal stability and is used for indirect heat transfer. Because of its advantages of uniform heating, accurate temperature control, high temperature under low vapor pressure, good thermal conductivity, energy saving, convenient transportation and operation, etc., it has been widely used in various occasions in recent years, and the amount of use and dosage is increasing day by day. Today, Bian Xiao will take you through the understanding of heat transfer oils.

According to the composition and manufacturing process, heat transfer oil can be divided into synthetic heat transfer oil and mineral car heat transfer oil.

Heat transfer oil is a high-temperature lubricating oil, usually made from mineral oil or synthetic oil, with good thermal conductivity and stable chemical properties.

It is commonly used in high-temperature industrial equipment, such as heat exchangers, heating furnaces, hot blast stoves, etc., to transfer heat and maintain a stable temperature of the equipment. Common heat transfer fluids include silicone oils, polymer oils, alkylbenzene oils, etc.

You can understand the heat transfer oil with medium energy temperature control, and the quality of the chain is guaranteed by the limbs!