Difference between main and branch liquid paths
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This post was last edited by Miaomushan de Quake on 2019-6-18 09:23. As shown in the diagram: under ideal conditions, ignoring factors such as pressure drop and pipeline resistance losses, the outlets of all five branches are open systems. There is one main liquid pipe with a DN50 diameter, an flow rate of 8 m3/h, and a pressure of 0.4 MPa. The five branches are as follows: Branch 1 is connected to a DN25 pipe, with a DN25x20 reduction in diameter afterward; Branch 2 is also connected to a DN25 pipe; Branch 3 is connected to a DN40 pipe; Branch 4 is also connected to a DN40 pipe; and there is Branch 5, connected to a DN25 pipe. So, Question 1: What are the flow rates at the outlets of each of the five branches? Question 2: What are the pressures at the exits of the five branches? I hope the experts on this forum will kindly offer their guidance: handshake
Can it be calculated with just one diagram like this?
Ignoring pipe loss, the pressure is equal to 0.4 MPa
The flow split is related to the resistance drop of each branch
I don’t know what the questioner’s intention is – to seek advice or to test something? I can tell you for sure that the problem you’ve posed has no solution, not even if a deity descended to earth. Because this question of yours is imaginary – it’s neither possible nor complete, so there is no solution. I wonder, if the flow rate is 8 m3/s, will the pressure be 0.4 MPa? At this flow rate, the velocity head alone already far exceeds this value. If these two values are within a reasonable range, and once the lengths of each pipe segment and the installation plan have been determined, it can be calculated using a computer. It’s better to calm down and study fluid mechanics properly.
One thing is certain: the sum of the pressure drop and the velocity head for each branch pipe is equal. This is also the basis for calculation using electronic computers.
I made a mistake; it’s 8 m3/h. I’ve had some doubts regarding certain issues related to the main pipes and branch pipes, so I’ve listed the questions that came to mind and am here to ask for advice: handshake
I’m just creating a simple diagram to ask everyone some questions
In an open system, regarding the pressures at the outlets of the 5 branches, could branch 5 cause the pressure in branch 4 to decrease?
What if we ignore resistance and pressure drop?