I have some small questions regarding exhaust gas recovery and would like to ask the more experienced experts for advice
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In the exhaust gas recovery process, there is a step where 10 bar of steam is used to heat and pressurize the water in the tank, thereby pushing the water toward the hot and cold medium pumps. These pumps then send the water to the heat exchanger. However, the flow rate of the water coming out of the hot medium pump fluctuates regularly: it stabilizes for a while, then drops again, before stabilizing once more. This pattern is very disturbing. I would like to ask the experienced colleagues what could be the cause of this issue – could it be due to unstable steam supply, or is there some other reason? ? The question should be clear now
The poster’s description isn’t very detailed; regular fluctuations are likely closely related to the steam quality. You use steam to heat and pressurize the water in the hot water tank. From your description, it seems that the flow rate of water is affected by the pressure in the tank. The pressure in the sink is closely related to steam. Steam boilers need to have water added to them over time due to water loss. During the water replenishment process, the quality of the steam is severely affected, resulting in a decline in steam pressure and stability; the heat capacity of the steam decreases, before returning to normal after some time. As a result of being affected by steam, the situation described by the poster occurred.
Is there a flow control valve on your steam feed line to regulate the pressure? If so, I have a reasonable explanation!
The effect of steam pressure on it is limited. It’s possible that poor venting of the pumps and pipes during initial operation could be a factor. As for what you mentioned regarding the supply of water to the hydrogen adsorption tower, the venting issues of that tower should also be considered, especially those related to the internal coils!
One thing that is certain is that there is air present in the pipes. One possible explanation is unstable steam pressure; when the pressure drops suddenly, the hot water in the pipes vaporizes, which leads to the phenomenon described by the original poster.
There should be air resistance; I agree with the person above
2# chjzhou Thank you, brother, for helping me figure this out. I think what you said makes a lot of sense; thanks for the discussion
3# yezi7414 If so, how would you explain it?
5# yangzhj521: First of all, thank you to this expert for helping me analyze the problem. But I want to ask: the flow rate of the heating medium water fluctuates at times and remains stable at other times. If it’s due to air resistance, I think the flow rate should fluctuate continuously; in that case, it’s hard to explain this situation, right? ?
Such fluctuations are certainly present. As you mentioned, water and steam form a two-phase flow inside the pipe, and due to the different flow velocities of the gas and the liquid, different flow patterns are created. Under the conditions you described, the flow pattern is either plug flow or slug flow, which is why there are certain fluctuations. To prevent fluctuations, the flow rate system should be increased for greater stability. You can refer to the flow of two-phase flow in pipes