Problems with flow velocity in nozzles and heat exchange tubes under vacuum conditions
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Recently I have made some plans, some of which are negative pressure with an absolute pressure of only a dozen Kpa. During the design process, the flow velocities on the shell side, tube side and nozzle were all very large. Since I had no previous experience in designing this type of heat exchanger, I controlled the flow velocities within 50m/s. My colleagues, have you ever designed a similar heat exchanger? What is the approximate flow rate on the shell side, tube side and nozzle side?
Check the heat exchange equipment manual. I guess the speed you set is relatively high.
Steam exhaust condensation, I took 30-40m/s. It is for reference only.
The author has provided you with the heat exchange tube length and heat exchange tube specifications. I want to calculate the flow rate mainly considering the pressure drop limit. For a negative pressure like yours, I can give you 1 to 2 kpa. I think your flow rate is on the high side.
My heat exchanger is a 12-inch heat exchange tube with a length of 1100mm. On the side of the gas outlet shell, the three baffles form a U-shaped tube heat exchanger. The final state used on a vacuum pump is to evacuate to 10Kpa. I used HTRI to simulate, the pressure drop is very small 0.2Kpa