Oil product metering issues
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In the process of measuring oil products, measurements are taken for length and temperature, and then a series of calculations are performed to convert these values into mass. Is it possible to install a device similar to a pressure gauge at the bottom of the tank to directly measure the mass of the oil?
It’s a curious idea of mine,
For atmospheric pressure oil tanks, a simple method has been in use for over 30 years: a nitrogen bubble gauge tube is installed near the bottom of the tank wall (inserted to a certain length inside the tank to reduce wall effects). During measurement, the nitrogen valve is opened and the pressure of the nitrogen bubbles is measured; this value represents the static pressure of the material inside the tank. By using a pre-determined relationship between liquid level and the volume of material inside the tank (to account for variations such as tank size and irregularities), it is easy to calculate the amount of material present. Formulas can be incorporated into the DCS system to automatically indicate the material quantity, and continuous indication is also easy to achieve. Previously, instrument air was also allowed to be used in place of nitrogen for Category C materials.
What I have in mind is to install a pressure gauge at the bottom of the storage tank under normal pressure; by using the pressure on its pressure-bearing surface, it is possible to determine the mass of the liquid column per unit area of force, and thus calculate the mass of the liquid inside the tank. (In this approach, I take three factors into consideration: the pressure of the gas phase above the liquid level, the mass of the floating disk if one is present, and the changes in the pressure exerted by the floating disk on the liquid surface when the tank is filled or emptied. The direction of the frictional force acting on the floating disk changes as it rises or falls, which in turn affects the pressure it exerts on the liquid surface.)
There are instruments with online weighing capabilities that can achieve this function, but such instruments can also experience inaccuracies; conditions such as rain, snow, or strong winds can cause deviations in the readings
I don’t know how to weigh a storage tank with tens of thousands of cubic meters in volume
The blowing method for measuring material volume is generally suitable for dome tanks, but not for floating roof tanks.
That’s a good idea, but the error might be quite large
Large pressure changes in large storage tanks have a tremendous impact
You need to have an idea; who knows, it might come true one day{:1_90:}