There are a few questions I don’t understand; I hope fellow netizens can help me out
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1. Given that the second virial coefficient of CO2 at 0 degrees Celsius is B = –0.151 m3/kmol, what is the pressure required to compress CO2 to a density of 80 kg/m3 at 0 degrees Celsius? Answer: 3,000,000 Pa. How is this calculated? ? ? ? 2. When a fluid flows in a circular straight pipe as an end-flow, the velocity at the center of the pipe is measured to be 2.2 m/s. What is the average flow velocity across the pipe cross-section approximately? The answer is 1.76 m/s. I only know that the average velocity in laminar flow is half of the velocity at the center; but how is the velocity at the edges calculated? What is the formula for that? 3. Why does the liquid entrainment line move upward when the plate spacing is increased? With all other conditions unchanged, increasing the plate spacing reduces the amount of liquid mist entrained; shouldn’t the entrainment line move downward? Why move upward? 4. Is the relative density of the liquid in the formula for calculating the fluid discharge volume of a safety valve inside or outside the square root? ? (Some use S or G to represent relative density.) I see that in some formulas it is included inside, while in others it is outside; in Tian Da’s textbook it is outside, and I’m confused – what exactly is the rule? Please give me some advice.
For the third case, where the plate spacing is increased, more volume is required for flooding to occur~ I think~ I’m not too sure about the other aspects; please provide an explanation~~~~~
The relative density of the liquid in the formula for calculating the fluid discharge volume of a safety valve is placed inside the square root.
Is that how question two is calculated? I would appreciate it if fellow sailors could offer some advice
During turbulence, the average flow velocity is approximately 0.8 times the flow velocity at the center of the pipe; thus, it is 0.8×2.2=1.76
Is it inside the square root? In Tianjin University’s textbooks, it’s calculated outside, but in the repeated-problem set, it’s calculated inside. So, is it inside or outside? ? ? ?
Is it inside the square root? In Tianjin University’s textbooks, it’s calculated outside, but in the repeated-problem set, it’s calculated inside. So, is it inside or outside? ? ? ?
The second day is very simple; it’s mentioned in the book: during turbulence, the average flow velocity is approximately 0.8 times the flow velocity at the center of the pipe!
For question three, it can be understood in this way: increasing the plate spacing reduces the likelihood of foam entrainment, thereby expanding the suitable operating range; hence, the upper limit for the gas phase should be raised. The same logic applies to the analysis of the other lines as well.
In the formula for calculating the safety valve, is the relative density S inside or outside the square root? ? ? ? ? ? Is the Tian Da book based on external factors, while the *question is calculated using internal criteria? Everyone, please talk more about where it is
By increasing the plate distance, entrainment is less likely to occur, so the gas phase volume can be increased