High-pressure turbine II

High-pressure turbine II is an upgraded turbine building that converts supplied steam into rotational power for the connected shaft. Like other turbines, its output is governed by efficiency, so it is strongest when the shaft has room to accept more load and weakest while it is ramping up after being started or restarted from idle.

Its efficiency is defined as the ratio of produced power to used power. In normal operation, efficiency drops when the connected shaft charge rises above 80% of capacity. The in-game relationship is:

• Efficiency(%) = 100 - 500 × {(shaft charge / shaft capacity) - 0.8}

Efficiency also falls during startup. When the turbine has just begun supplying or has restarted from idle, it takes about 28.4 s to reach full efficiency, and the efficiency rises over time during that startup period. Because of this, if the turbine receives less steam than it requires, its average power output drops sharply; for example, at only half of the required supply it produces 2.0 MW on average.

When auto-balance is enabled, the turbine will automatically go idle once the connected shaft reaches 80% charge, then restart when the shaft charge falls to 35%. This is useful for conserving steam, but it also means the turbine needs time to return to full power after restarting. For a stable electrical supply, it should be paired with enough flywheels to buffer the startup delay.

• Keep shaft charge below 80% if you want to preserve turbine efficiency.
• Expect a significant temporary output loss after any idle-to-active restart.
• Auto-balance saves steam, but it is not ideal for loads that need uninterrupted full power.
• Flywheels help smooth out the power drop while the turbine is ramping up.

The values described here were tested in version 0.5.2, and the building’s appearance changed before version 0.5.0.