How should the inlet pressure of the rich gas compressor in a steam turbine be adjusted optimally?
Thread Content
From what I’ve seen so far, some use anti-surge valves to regulate the inlet pressure, while others use the rotation speed to do so. Which method is better?
How to adjust the compressor inlet pressure is an issue that needs to be considered in the process; it is unrealistic to attempt to control anything that leaves the process, as the requirements of the process must be met.
This post was last edited by icewater1981 on 2015-10-15 at 15:33. The correct approach is to use speed as the main control mechanism, with the anti-surge valve serving as a supplementary control element. This allows the surge valve to be kept at the lowest possible opening degree, thereby meeting the process control requirements while reducing energy consumption. For example, assuming that the surge point is far from the surge line, then, if only surge prevention is considered, the surge preventer valve can be completely closed. If the actual inlet pressure is lower than the set value, there are two options: 1. Maintain the current speed, open the anti-surge valve, and increase the inlet pressure; 2. Keep the anti-surge valve closed, reduce the compressor speed, and increase the inlet pressure. Both methods achieve the goal of maintaining the inlet pressure, but the second method is much more energy-efficient than the first, so it is clearly the better option. However, when there are significant fluctuations in the inlet pressure, such as a sharp drop, reducing the speed cannot quickly restore the pressure. Considering also that an instantaneous drop in inlet pressure is itself a sign of a decrease in the amount of air drawn in at the inlet, it is necessary to open the surge valve promptly at such times; this ensures that the inlet pressure is maintained and prevents the risk of surge in the unit. Furthermore, various control strategies such as inlet pressure limit control, decoupling control, and surge prediction control can be integrated into the compressor control scheme to enable smoother operation of the unit. The above are the answers provided by the manufacturer of the aircraft control system upon consultation.