Why is the gas turbine speed constrained by the grid after it is connected to the grid?

The speed of the steam turbine is directly proportional to the frequency. When the unit is connected to the grid, the voltage, frequency, and phase must be kept within the allowable range with the voltage, frequency, and phase difference of the grid, and if the difference is too large, the unit may be damaged (if it is not delisted in time).

After the turbine is connected to the grid, the frequency is consistent with the grid. If the air intake of the steam turbine is too large, the grid frequency will increase, but in reality, because the load of the grid can be regarded as an infinite system relative to a certain group of steam turbines, the air intake of a certain unit increases, and the grid frequency changes very little, so it feels like being constrained by the power grid.

It's like a very slow train that is moving at a constant speed, and a person pushes it, and the speed of the train actually increases, but because the manpower is negligible compared to the train, the speed does not change within the measurable range, but is like a train leading people to run.

The speed of the steam turbine determines the frequency, because the power of the power grid is much larger, the power of the steam turbine is much smaller, after the steam turbine is connected to the grid, the speed of the steam turbine can not change the frequency of the power grid, and can only be controlled by the frequency of the power grid, and the synchronous operation of the power grid is stable.

Because after being connected to the grid, the output power of the generator has been affected by the fluctuation, which directly affects his electromagnetic torque, which also has an impact on the frequency.

In fact, as long as the exhaust temperature of the low-pressure cylinder is not very high, not more than 60 degrees, it should be able to run for time. The biggest impact on the steam turbine is mainly worried about the small steam flow and the high temperature of the exhaust cylinder caused by the blast friction of the final blades, which may induce vibration and leakage of the copper tube of the condenser.

If long bai

Time can not be connected to the grid, it is best to enter the state of du coiling. How long is 3000 rpm There is no hard DAO regulation back, and the main thing to pay attention to is the exhaust temperature of the low pressure cylinder.

3000 rpm is not connected to the grid for a long time, first, it consumes energy and is not economical;

2. At 3000 rpm, the steam turbine needs to be inlet in the whole circumference, and the opening of the adjusting door is too small, and the blowing loss of the adjusting door is aggravated;

3. The length of the blades at the end of the steam turbine is long, the air intake of the steam turbine is small at 3000 rpm, and the exhaust heat generated by the impeller at the end of the low-pressure cylinder cannot be taken away, which will endanger the safety of the blades.

The steam turbine allows a constant speed of 3,000 rpm, but it wastes more steam.