【JST-053】One-on-one office for air separation compressor turbine operation

The exhaust pipe of the turbine in our unit has been vibrating frequently lately. We have checked for any leaks, and we suspect that the high vacuum level may be causing backflow. The vibration stops when we reduce the vacuum level to 69 Ka, but this problem did not occur when the vacuum level was higher before. I would like to know what is causing this issue?

1. Check whether the hot well liquid level is normal. 2. Check whether the water level in the seal of the atmospheric safety valve has dropped.

Hello: I would like to confirm whether the exhaust pipeline you mentioned refers to the section between the turbine’s exhaust end and the cooler? If so, may I ask: are you sure the vibration comes from this pipeline? Secondly, is it possible for vibration to be transmitted? Secondly, have you carried out any other operations? Does it start gradually during the production process, or does it occur after stopping and restarting? Have there been any changes in the parameters of other devices? Regarding the question you raised, based on the possible reasons: 1. Vibration at the condensate pump is transmitted to the exhaust pipe through the pipes. 2. If the vibration of the exhaust pipe is significant, it will affect the cylinder behind the turbine, causing imbalance in that cylinder; this in turn leads to changes in shaft end temperature, vibration, displacement, as well as in the sealing conditions. 3. Has there been any change in the condensate water temperature? Should the exhaust conditions be taken into consideration on the water side of the turbine exhaust cooler? 4. Analyze the condensate to determine whether there is a tube bundle leak causing the instability. 5. Examine the area around the equipment to check for any devices that cause significant vibration, which might be responsible for vibrations in this area, such as two-stage injectors. I’m not familiar with the layout of your equipment either, so I can only make guesses. I hope the points I’ve mentioned above will be helpful to you. Next time, you could tell us the model and manufacturer of the turbine; there might be some common issues that we can all share information about. I hope your problems will be resolved soon, and I hope you’ll share the situation with everyone. I’m continuing to think about this issue, and the answer will be added later. . . . . . .

Hello, I just want to know how the manufacturer determines whether to use exhaust fans to remove air from the oil station of the unit, or to inject low-pressure nitrogen into the oil tank. How was it determined which of these two processes to choose?

This post was last edited by lifawei109 on 2012-4-11 at 16:02. Hello, the exhaust fans used in gas stations serve the following purposes: 1. To increase the vacuum level in the fuel tank, thereby ensuring smoother operation. 2. Increase the flashing capacity to draw away the smoke from the tank, as well as the moisture present there, thereby ensuring the quality of the lubricating oil. Regarding the process you mentioned of filling the email box with low-pressure nitrogen, I have no experience with this method. However, I can imagine that such a process would need to meet certain conditions: 1. After the system is shut down, there must be another parallel system available to supply nitrogen. 2. The system return oil pipeline needs to be large enough to allow for timely oil return. 3. No requirements are imposed on the system’s return oil pressure; it can be forced into the tank through the inlet oil pressure. In the case you mentioned, low-pressure nitrogen should be filled into the email, but there is still a smoke exhaust fan, right? This approach not only helps to maintain a vacuum level and ensure smooth oil return, but it also accelerates the evaporation of water present in the oil tank. The use of nitrogen is optional; its inclusion is merely beneficial for the oil system. It’s a matter of design philosophy – some companies believe that nitrogen isn’t necessary, as few companies use it, while others insist on its use to better protect the quality of the oil. This reflects the cultural differences and characteristics of each company. Every designer and design company has its own approaches, but ultimately, the design should be tailored to the actual conditions. For you, this issue serves as an extension of knowledge points; ordinary technical engineers do not need to know detailed information on this topic – they only need to understand the principles, functions, as well as how to operate and maintain the system more effectively. I hope my answer can resolve your doubts.

Thank you for your answer. I have worked with both oil mist fans and devices used for filling tanks with low-pressure nitrogen. Relatively speaking, I’ve been working with oil mist fans for only a short period of time, about two to three years. I understand the functions of oil mist fans, but I don’t understand how manufacturers decide whether to use nitrogen or fans. The two points you mentioned are incorrect; however, it’s not your fault since you haven’t had experience with this. After the system stops operating, there are no other pathways through which nitrogen can be introduced. 2 Nitrogen-filled fuel tanks do not have exhaust fans. The diameter of the 3-return oil pipelines is almost the same as that in the units with fans that I have worked with… The only difference is the manufacturer of the compressors; all the steam turbines are from Hangzhou Steam Turbine Co. For equipment equipped with fans, compressors, and boosters, Shaanxi Blower is the supplier. The nitrogen-filled compressors and boosters are from Siemens…

This post was last edited by hxm2087 on 2012-4-12 07:07. Thank you for your feedback and criticism; may I see the PID diagram for the tank filled only with nitrogen? I’d like to learn *about it. I’ve never seen a fuel tank that contains only nitrogen; I want to see what features your fuel tank has.

I don’t have a diagram of the tank; it’s no different from the tank used in the oil mist fan, with the only difference being a 50MM pipe that connects to it from the nitrogen pipeline of the low-pressure system. The flue for exhausting smoke is a straight pipe that leads smoothly outside the factory building. The rest of the pipes are no different from those in other fuel tanks

There is one air compressor and one booster pump. The vibration level at one vibration measurement point of the air compressor increases as the oil temperature rises, while the vibration level at one vibration measurement point of the booster pump decreases as the oil temperature rises. Why is that? What is the relationship between vibration and oil temperature?

Our workshop’s fuel station is equipped with an oil mist fan as well as low-pressure nitrogen pipelines. I’m actually a bit confused by your question. As for the function of the oil mist fan, I think everyone knows more about it than I do (I’ve only been working with air separation systems for half a year). In my opinion, the main purpose of filling the system with low-pressure nitrogen is to remove moisture, since nitrogen is relatively dry. Even when both of these accessories are used, it’s still necessary to maintain a slight negative pressure inside the fuel tank, given that the amount of nitrogen used is quite small. Could the differences in design be related to the region? ! For example, in areas with a more humid climate in the south, it might be necessary to install a low-pressure nitrogen pipeline; but here in the north, such a pipeline isn’t even needed at all (it was decided by our workshop supervisor, hehe). It’s just my humble opinion – let’s learn from each other!