What is the extraction pressure in an extraction turbine typically maintained as?

In an extraction turbine, the extraction pressure is typically maintained constant regardless of the turbine load to ensure stable operation and maintain the desired performance characteristics. By keeping the extraction pressure consistent, it allows for predictable control of the steam conditions used for processes such as steam heating or feedwater heating downstream. This predictability is vital because variations in extraction pressure can lead to fluctuations in temperature and flow rates, potentially destabilizing the systems that utilize the extracted steam.

A constant extraction pressure helps optimize efficiency and thermal performance. When the turbine is designed and operated correctly, maintaining a steady extraction pressure mitigates the risk of inefficiency due to steam property changes while providing reliable steam supply for auxiliary operations.

The idea that extraction pressure varies according to turbine load or is proportional to it introduces complications that can detract from efficiency and effectiveness in operational control since varying pressures could lead to unpredictable outcomes for downstream processes. Therefore, maintaining a constant extraction pressure aligns with best practices in steam turbine operation.