Abnormal heating in the stabilizer bottom reboiler
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Before the reboiler was heated, the temperature at the bottom of the stabilizer was 150°C; the temperature at the outlet of the reboiler had risen to 185°C, yet the temperature at the bottom of the tower remained around 150°C. Continuing to heat the reboiler only increased the temperature at its outlet, without raising the temperature at the bottom of the tower.
Initially, it was suspected to be a gas blockage; after stopping the steam used to heat the reboiler, the temperature at the reboiler outlet dropped to 130°C, and heating was resumed, but the problem persists.
This situation may be caused by the following reasons: 1. **Poor circulation**: The circulation flow rate between the reboiler and the bottom of the stabilizer may be insufficient, preventing the heated fluid from returning effectively to the bottom of the tower. 2. **Blockage inside the tower**: There may be blockages within the stabilizer tower, which affects the return flow of hot fluids. 3. **Separator issues or damaged internal components**: The separators or other internal components of the stabilizer tower may be damaged or improperly installed, which affects heat distribution and fluid flow. 4. **Temperature sensor failure**: The temperature sensor at the bottom of the tower may fail, resulting in inaccurate readings. 5. **Design issues**: If the design of the reboiler or its connection to the bottom of the tower is inadequate, it can also lead to low thermal efficiency. Solutions include checking the circulation system, removing any blockages inside the tower, inspecting and repairing the internal components, verifying or replacing the temperature sensors, and re-evaluating and optimizing the design. It is recommended to first conduct a systematic inspection and maintenance to see if the problem can be resolved. If the problem persists, further technical improvements or equipment adjustments may be required. .
First, consider air resistance; another point is to avoid raising the temperature too quickly. The main issue is poor circulation, so it depends on how you operate it – just resolve the circulation problem and it will be fine
The design issue shouldn’t be the problem; the reboiler was working fine before and only started acting this way recently. I’ll check the instruments for any issues. I was wondering if there are any good ways to solve the problem of poor circulation
I have turned off the heating steam completely; after cooling down, I tried to restart it twice, but the result was the same – no change. The heating rate is around 15°C per hour, which isn’t fast at all. Are there any other good ways to solve the loop problem?
What software was used to create this diagram? It’s very intuitive and clear.
Did it occur at the time of startup? If it happened during startup, it’s likely still a problem related to gas blockage; perhaps there were liquids such as liquid hydrocarbons present at that time, and their vaporization caused the gas blockage. Go and check the process yourself, identify where the gas blockage might be, and see if it can be resolved by releasing that gas. Additionally, you can also try adjusting the liquid level at the bottom of the tower to address the issue. If it’s convenient, please send some photos from the site so we can see what the setup is like
Has the property of the material changed, preventing thermal siphon effect from working? Check the liquid level
Construction started in October 2023, and the situation has remained the same ever since. Since the sulfur content in the oil samples was within acceptable limits, no attention was paid to it. It was only recently that an increase in sulfur content was detected. The liquid level was also increased; operations were carried out at full level for 5 hours, but with no effect. The instrument issue has been checked, and there are no problems.