Flow rate calculation
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Experts, how can I calculate the mass flow rate of a substance when the system pressure is 1.0 MPa, the pipe diameter is 300 MM, and the density is 700 kg/m3?
The conditions are not clear; to determine the mass flow rate, it is first necessary to know the flow velocity, which can be determined using Bernoulli’s equation. If the system pressure refers to the pressure inside the tank, then, assuming that pipe resistance can be ignored, it is also necessary to know the liquid level in the tank. In a steady-state system, the calculation is simple, as the mass flow rate remains constant. In a non-steady-state system, Bernoulli’s equation can be applied at a specific moment, and after differentiating and integrating, the calculated mass flow rate is not constant
It is necessary to know the pressure difference from point A to point B in the pipeline
The average flow velocity inside the pipe is also needed, but I think it cannot be calculated using Bernoulli’s equation (p1+1/2ρv1^2+ρgh1=p2+1/2ρv2^2+ρgh2); in this equation, v1=v2, so those values cancel each other out. I’ll check what is known about this
If it’s an estimation, the approximate flow rate can also be calculated by looking up a table! :)
OP. The question is to find the flow velocity, while the problem in the post is to find the flow rate. However, the two are related; a condition is missing. Mass flow rate = density * volume flow rate = density * flow velocity * (3.14 * 150^2)
Choose the appropriate flow rate, calculate the volumetric flow rate based on the pipe diameter, and then multiply by the density to obtain the mass flow rate!
That’s not what I mean. I want to know what the maximum flow rate can be for a certain diameter under a certain pressure