Regarding lubricant temperature
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Our hydrogenation unit is equipped with a shaft head pump, and the auxiliary oil pump has a interlocked start condition that triggers it when the oil temperature is below 20 degrees Celsius. I would like to know why this condition exists Isn’t it bad when the oil temperature is low?
Low oil temperature results in high viscosity and poor flow properties
The viscosity-temperature behavior of the lubricating oil is the main consideration
For lubricating oils, physical impurities and chemical composition are the key factors to consider, while oil temperature is related to the kinematic viscosity of the oil and affects the stiffness of the oil film. Poor lubrication can cause damage to the bearing shells. For example, API requires the use of 46-grade turbine oil in compressors, with an operating temperature of 45 degrees plus or minus 5 degrees. In many domestic compressor testing conditions, an oil temperature of 35 degrees is also allowed for testing. At a fuel station for a certain unit on the Qinghai-Tibet Plateau, due to the high altitude, the oil starts boiling at around 10 degrees, which prevents the unit from operating.
Different oil temperatures affect the viscosity of hydraulic oil. The higher the temperature, the lower the dynamic viscosity of the oil, which leads to increased leakage from the pump and reduced efficiency. Conversely, lower temperatures result in higher dynamic viscosity, which can interfere with the proper operation of the pump, increase energy consumption during flow, and also have a significant impact on the proper functioning of valves, as the valve spools are more likely to get stuck.
When the oil temperature is too low, the viscosity of the oil increases, which makes it difficult to form a proper lubricating film. The auxiliary pump is started to increase the amount of lubricating oil, thereby facilitating the formation of a lubricating film.
The auxiliary pump is started to increase the lubricating oil temperature, right? . .
Is there a fuel tank heater? Wouldn’t it be better to set the interlock temperature for the fuel temperature heater to start operation at a level below 20°C?
If the oil temperature is too low, the lubrication effect is poor. Actually, 20 degrees Celsius is a bit high; 15° might be more appropriate for the interlocking mechanism.
Generally, the auxiliary oil pump is started only when the oil pressure is low； The heater is usually turned on when the oil temperature is low. Are you sure you haven’t made a mistake?
45℃≥oil temperature>27℃.