Thermal stability is the most important performance of a heat transfer fluid. Different thermal stability, the degree of thermal cracking and polymerization in its use are also different. Thermal cracking produces small molecular low-boiling substances, which can easily cause air resistance in the system and cause cavitation of the pump.At the same time, it also causes higher evaporation loss and environmental pollution of the oil products; thermal polymerization produces large molecular high-boiling substances, which gradually deposit on The carbon deposits formed on the surfaces of heaters and pipes will affect the heat transfer efficiency and temperature control accuracy of the system. LQ series heat transfer fluids are selected from base oils and additives with excellent thermal stability, so the product has excellent thermal stability.
Oxidative stability is another important performance property of heat transfer fluids. The open system or expansion tank does not use a nitrogen closed system, and the interface between the oil and air contact will oxidize. Generally speaking, under the condition of higher than 60 ℃, the oil will oxidize when it comes into contact with the air. The oxidation products will gradually form colloid and sediment, which will adhere to the surface of the heater and the pipeline to produce carbon deposits. At the same time, the acidic substances produced by the oxidation reaction will also corrode equipment and cause leakage. LQ series heat transfer fluids are selected from base oils with excellent oxidation resistance and high temperature anti-oxidation and anti-scaling additives, which can inhibit the rate of oxidized sludge and the tendency to deposit and scale, so that the system maintains good heat transfer effect.
The heat transfer fluid uses its initial boiling point to indicate its volatility. The heat transfer liquid used in the open heating system, if the initial boiling point is lower than the use temperature, it is easy to cause cavitation of the pump, air resistance of the operating system, and excessive evaporation loss. The higher initial boiling point of the LQ series heat transfer fluid makes it have low vapor pressure and volatility loss, which can ensure the smooth operation of the system.
The heat transfer fluid uses its flash point and spontaneous ignition point to indicate its safety. The flash point is used to indicate the safety performance of the heat carrier in a closed cycle system, and the auto-ignition point can predict the tendency of the auto-ignition in the air when the heat transfer fluid leaks under high temperature conditions. LQ series heat transfer fluid has high flash point and spontaneous ignition point, which can ensure the safety of system operation.
Heat transfer performance
LQ series heat transfer fluid not only has high thermal stability, but also has excellent heat transfer performance. Appropriate viscosity can provide higher cycle efficiency; higher specific heat and thermal conductivity can effectively transfer or absorb heat, improving fuel economy and operating efficiency.
When the LQ series heat transfer fluid of the open heating system is used in a heat transfer system in which the expansion tank is not sealed with nitrogen, the oil temperature in the expansion tank should be kept below 60 ° C, and the maximum oil temperature should not exceed 180 ° C.
The closed-type heating system LQ series heat-conducting liquid has a longer service life because it is isolated from the air when it is used in a heat transfer system closed with nitrogen.
Maximum use temperature The maximum use temperature refers to the temperature corresponding to the deterioration rate of a product measured by the thermal stability test of not more than 10%, that is, the highest average temperature of the main fluid measured at the heater outlet. In actual use, the average temperature of the main fluid measured at the heater outlet should be at least 20 ° C lower than its maximum use temperature. After evaluation, the maximum temperature of L-QB heat transfer fluid is 300 ℃, the maximum temperature of L-QC heat transfer fluid is 320 ℃, and the maximum temperature of L-QD heat transfer fluid is 350 ℃.