Gas flow rate in the pipeline
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Hello everyone: I have a simple question – I’m not sure how to simulate it. Could you please give me some guidance? Thank you. Given: The nitrogen pressure at the pipe inlet is 7 kg, the back pressure at the pipe outlet is 0.5 kg, and the pipe diameter is 80 mm. Determine the flow rate within the pipe and explain how to simulate it
Do we need to simulate this? Can’t it be roughly calculated based on the flow rate?
Yes, it can be calculated based on the economic flow rate. But for such a simple problem, in order to obtain more accurate calculations, I created a pipeline and a flash tank simulation; however, the results of the simulation differed greatly from the calculations. Therefore, I would like to ask how to conduct such simulations.
I haven’t done any simulations; please give me some support. I’m also curious whether traffic can be simulated as well?
This is a unsteady transient process, which should be able to be simulated using Aspen Dynamics/HYSYS
With an inlet and outlet pressure difference, can the flow velocity be determined from the pressure drop, and then the flow rate be calculated? Further data such as pipe length, pipe and valve fittings, and gas temperature need to be provided
This issue is very practical; for example, during shutdown purging and in design, the nitrogen pressure remains constant, usually at 7 kilograms. The back pressure when purging containers, tanks, or pipes with nitrogen is also fixed. Sometimes it’s necessary to estimate how much nitrogen is required, or to determine the maximum amount of nitrogen needed for purging a DN100 pipe. Estimating the flow rate based on economic flow velocities is highly inaccurate. Therefore, an accurate simulation is required; the nitrogen temperature is generally 40 degrees. I’m not sure if this simple problem can be simulated using PRO11 software
It is not possible to carry out simulation based on just these conditions; if the pipeline is short and the pressure drop is less than 7 – 0.5 kilograms, then the outlet pressure will be greater than 0.5. At the outlet, the pressure drops, and the pressure energy is converted into kinetic energy. It is necessary to know the actual outlet pressure, and the flow velocity can be easily determined using Bernoulli’s equation, from which the flow rate can be calculated. If the pipeline is very long and the pressure drop is 7–0.5 kilograms, it can be calculated easily using Bernoulli’s equation.