The turbine inlet pressure is insufficient and the compressor is surging; what should be done?

This post was last edited by Refiner on 2018-5-21 13:51: Export fire torch

Open the flare valve at the inlet to control the pressure at the top of the distillation tower; open the anti-surge valve sufficiently to prevent surge in the compressor; reduce the pressure in the stabilization system as appropriate; shut down the plant urgently if necessary

As the steam pressure at the turbine inlet decreases, the relative work output of the unit is reduced; while with an unchanged outlet pressure, this can cause surge in the compressor! At this point, you should open the inlet valve promptly and gradually close the surge valve to ensure that the unit stays away from the surge zone. Another good approach is to reduce the processing volume, lessen the load on the unit, and stay away from the surge zone!

Adding to what was said above: if it is driven by a back-pressure turbine, the steam back-pressure can be reduced without affecting the operating conditions of the turbine

This post was last edited by Refiner on 2018-5-21 at 13:52. The high distillation pressure is due, first, to a low rotation speed, and second, to the anti-surge valve being fully open. Firstly, the main steam pressure is low, making it difficult to increase the rotation speed; furthermore, if the anti-surge valve is closed, the distillation pressure may drop, but surge conditions will worsen. In such a situation, it is necessary to find ways to quickly increase the main steam pressure, reduce the back pressure, and raise the rotational speed. Additionally, the stability pressure should be lowered; if that doesn’t work, the outlet valve should be opened to vent the steam. Once surging stops, the anti-surge valve can be gradually closed. If the problem still cannot be resolved, the compressor must be shut down – damaging the compressor will likely have serious consequences for you

This post was last edited by Refiner on 2018-5-21 at 13:54. This is a good post; let me share my views first: the goal is to eliminate or reduce surge, ensure the safety of the compressor equipment, and restore production. Therefore, 1) it’s correct to gradually open the anti-surge control valves in a sequential manner; 2) the increase in the pressure at the top of the distillation tower to above 0.2 MPA is caused by the turbine not being able to drive the compressor to perform work, resulting in pressure buildup in the distillation tower. 3) The compressor still experiences surge at this point due to a sudden drop in speed and excessively high outlet pressure. There must be some issue with timely adjustment, as well as with the coordination between the anti-surge valve and the outlet flare valve. My analysis and recommendations are as follows: 1) The anti-surge valve should not be closed completely; instead, manual adjustment should be used. If the pressure at the top of the distillation tower is high, it can be adjusted by using the inlet flare valve. Even if that isn’t done, the safety valve will activate, and the steam pressure won’t recover in a short time. In such cases, it’s necessary to inform the heating furnace to reduce its output urgently. 2. Compressor surging: Open the outlet to vent gas, or assign someone to shut off the manual valve used for absorption and stabilization on-site, or use the control valve for the dry gas at the absorption and stabilization outlet to vent gas in order to reduce the pressure in the downstream system. Generally, it is sufficient to just vent gas from the compressor outlet; the absorption and stabilization unit in the downstream system should remain unchanged, with adjustments made based on pressure levels. 3. Agree with what the senior colleague said – check whether the back-pressure steam outlet can be adjusted, as well as consider opening the vent for the compressor. There is a certain time period during which, once the pressure in the absorption and stabilization system drops, the compressor should start working properly. However, whether the distillation tower operates under pressure or not still requires adjustment through the flare at the inlet; it’s possible to use the absorption and stabilization system to discharge high-pressure gas from the system. I’m not sure if you have such a setup in place. ,

Reduce pressure via the anterior approach, and stabilize it using a posterior system. The condition for handling the issue is that there should be no overpressure ahead; if time is running out, it is necessary to vent promptly – under no circumstances should overpressure occur.

However, the larger the inlet opening for the flame, and the more the anti-surge valve is closed, the more likely the compressor is to surge