SU499408A1 - Turbine startup method - Google Patents

Description

one

This invention relates to a power system.

Methods are known for starting a turbine by influencing the speed and thermal conditions of the turbine on the valves of the high-pressure part and intermediate valves, such as shut-off valves after the intermediate superheater. In these methods, the speed controller acts on both groups of valves during the entire start-up, which does not provide a sufficient rate of heating of the turbine.

In order to accelerate the warming up of the turbine, according to the proposed method, the speed controller is disconnected from the intermediate valves before the rotor is thrust and re-connected before the turbogenerator is turned on under load.

The drawing shows the implementation of the described method.

The scheme includes a high pressure cylinder (HPC) 1, a low pressure cylinder (HPC) 2, valves 3 HPC, intermediate valves 4 after steam reheat (PP), a control mechanism 5 of the turbine, a speed regulator 6, a regulator 7 of the thermal state of the turbine .

The heating and start-up of the turbine according to the proposed method occurs in the following sequence.

With fully open intermediate

the valves 4 push the turbine by opening the control valves 3 of the high-pressure cylinder and exit to the first stage by the number of revolutions. In this case, there is a significant difference between the temperature of the internal surfaces of the turbine components and the saturation temperature of the steam in and HP 1. The speed controller 6 from the intermediate valves 4 is turned off. As the temperature warms up, the temperature difference decreases, and regulator 7 begins to cover valves 4, which leads to an increase in vapor pressure in CVP 1 and, consequently, to an increase in steam saturation temperature. This allows you to maintain the warm-up rate of CVP 1 at a level that is maximum permissible with respect to thermal stresses. As the valves 4 are covered up, the used heat loss decreases, and therefore, to maintain the set speed, the control valves 3 are opened using the turbine control mechanism 5 or speed controller 6.

The transition to the next step in the number of revolutions is ensured by the fact that, after reaching a predetermined temperature condition, control valves 3 and valves 4 are simultaneously opened by means of control mechanism 5 so that they do not produce a sharp pressure change in the high-pressure cylinder, after which the heating continues as described above.

As a result of successive transition through a series of such stages, the turbine goes to the operating speed, after which the thermal condition regulator 7 is turned off, and the valves 4 are placed under the control of the speed regulator 6.

This method allows accelerating the warming up of the turbine during start-up due to two main factors.

1. The rise in steam saturation temperature caused by the increase in pressure in the high pressure cylinder, and this pressure increase is limited only by the strength of the parts of the high pressure cylinder body and the steam path to valve 4.

2. Growth of steam consumption, which contributes to an increase in the intensity of heat exchange in the low-pressure cylinder 2

and accelerates its warming up.

In addition, at revolutions close to the workers, additional heating of steam in the HPC at the expense of ventilation reaches a significant value, which accelerates the heating of the HPC.

Claims (1)

Invention Formula The method of starting the turbine by acting on the speed and thermal conditions of the turbine on the valves of the high-pressure part and intermediate valves, such as shut-off valves after the intermediate superheater, characterized in that, in order to accelerate the warm-up of the turbine, the speed controller is disconnected from the intermediate valves before the rotor jerk and re-connect it before turning on the turbogenerator under load.