Calculation of pipe resistance? ? ?
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The friction loss of pipes calculated in chemical engineering handbooks refers to the pipes being in a horizontal position, or does it include the vertical position as well? According to some sources, a level difference of 10 meters is equivalent to a loss of 1 meter in head due to vertical height; so how is the vertical pipe resistance calculated? Is potential energy included as well, in addition to frictional losses?
Pipe resistance loss and outlet pressure drop are not the same concept; pipe resistance loss consists of straight-line pipe resistance and local resistance, and this loss represents the frictional loss of the medium. The pipe friction loss hf depends only on the pipe length, diameter, fluid density, flow velocity, viscosity, as well as the type and quantity of fittings and valves, and the relative roughness of the pipe; it is independent of whether the pipe is horizontal or vertical. Do not confuse concepts; treat the elevation difference as part of the pipeline friction loss. According to Bernoulli’s equation, the end points to be considered for calculation should be the starting point, the ending point, and the final point of the fluid flow; [Potential energy 1 + Kinetic energy 1 + Static pressure energy 1 + Effective pump work = Potential energy 2 + Kinetic energy 2 + Static pressure energy 2 + Pipeline resistance losses]. It is only in the case of vertical pipes that, due to the decrease in potential energy, the total energy decreases, resulting in a lower pressure; however, the cause of this pressure drop is not solely due to pipe friction. For the specific algorithm, refer to HGT 20570.7-1995 \"Calculation of Pipeline Pressure Drop\"
Great, man! I’ve gone through the standard material and got a general understanding of it, but the formulas are different from those in chemical engineering principles. . . . . . . . . But the calculation results should be the same. Thank you for the recommendation