Heat exchange tube pressure level
Thread Content
I have some questions about the pressure level of the heat exchange tube. For example, for a condenser, the shell carries high-pressure materials, and the pressure is 30 kilograms. Because circulating water flows through the pipe side, the pressure is only 4 kg. I always think that in this case, the design pressure of the tube side should be based on the shell side pressure level, but the actual situation is not like this. Can any experts help explain why this is?
Personally, I think that for ordinary heat exchangers, the tubes can withstand quite high pressure, so there is basically no problem. But what about floating head heat exchangers? Do we need to consider the sealing problem at the floating head flange? Should it be designed for high pressure? There is also the design temperature. Is it the same as the design pressure and is designed based on the respective medium temperature? Do we also need to consider the temperature yield limit for temperature? I don’t understand design and I hope you guys can help explain it.
Brother, please help me. Maybe this problem is relatively simple for you guys, but it is a big problem for me. I still hope someone can give me some advice and help.
In fact, there should be no doubt about the design pressure. Just follow the definition of GB150. Therefore, the pressure inside the pipe should be used as the basis for the design pressure. However, the cooling pipe is subject to high external pressure, so its strength and the relationship between the pipe and the tube plate need to be checked. Pull-off force, the foreigners we have trained in the past few days have given me a range of external pressure that the cooling tube can withstand. I will send you a data after sorting it out tomorrow. However, I can tell you for sure that the external pressure of your tube is not high. The heat exchanger we designed ourselves is suitable for your working conditions. 18* 0.9 stainless steel pipe and 16 * 1 B10 tube can be used
Thank you. I know this pressure is not high, but it is still a bit high compared to the tube pressure. So I'm still a little worried.
In actual production, in order to save resources, separate design pressures are adopted
According to what is mentioned in GB-151-99, the design pressure is the highest pressure that may be reached at the high point of the tube and shell. My personal understanding is that the actual operating pressure of the shell is higher than that of the tube side, so the design pressure of the tube side should be consistent with the shell. I don’t know, right?
You have not yet established a design concept for a multi-chamber pressure vessel. Take a look at page 9 of the Rules of Appearance. It is explained below: Multi-cavity pressure vessels (such as the tube side and shell of heat exchangers, the steam drum and heat exchange chamber of waste heat boilers, jacketed vessels, etc.) are used and managed according to the pressure chamber with a higher category as the respective category of the vessel. However, design and manufacturing technical requirements should be put forward according to the respective categories of each pressure chamber. The design pressure value in GB1513.11.2... Otherwise, the design pressure should be determined according to the working pressure of the tube and shell side respectively.