JPS58160502A - Starting method for combined cycle plant - Google Patents

Abstract

PURPOSE:To obviate the necessity for a specific starting motor by initially starting the captioned plant equipped with an exhaust recovery steam boiler, by utilizing a neighboring steam source arranged in parallel, other than the exhaust heat boiler. CONSTITUTION:When a plant is started, the low-pressure reducing valve 12 in an auxiliary steam header 13 system is opened at first to warm a steam turbine 3, and the revolution number of the steam turbine 3 is increased gradually. Then, a combustor 5 is ignited, and the output of the gas turbine 1 is increased gradually, and when the number of revolution of the shaft reaches above the half of the rated value, a stop valve 16 is closed. At the final stage, the fuel in the combustor 5 is increased gradually, and the number of revolution is increased to the rated value by the gas turbine 1. Thus, also the steam turbine 3 can be driven by the steam supplied from an exhaust heat boiler 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for starting a combined cycle plant comprising a gas turbine, a steam turbine and a generator.

In a combined cycle C2 in which a gas turbine, a steam turbine, and a generator are directly connected to each other on a single shaft C, the gas turbine is operated by receiving hot combustion gas from combustion 6, but at this time Fi fuel is supplied to the combustor. In addition to this, a large amount of air must be pumped in.

In order to create this air source, it is normal to directly connect a gas turbine I: an air compressor. In other words, since the pneumatic JII machine that does not drive the turbine does not operate,
The combustor is not working and the plant cannot be started in this one trench. At the ninth stage, an electric motor or diesel engine was installed as the starting motor, which was directly connected to the gas turbine shaft via a clutch, and by driving this motor, compressed air was obtained from a 9-atm pressure line machine and supplied for combustion.
tft - The combined r cycle of gas turbine pin and steam turbine can utilize the exhaust heat of the gas turbine, and the exhaust heat boiler I
: To configure the cycle of creating steam and supplying it to the steam turbine, the general C: still needs to start the gas turbine first, and JIA#na for startup is required.
I& is necessary.

An object of the present invention is to use a steam source outside the steam system of the steam turbine 62 to drive the steam turbine and use it as a prime mover for starting up. It is an object of the present invention to provide a highly effective method for starting up a combined cycle plant, which saves energy in time.

The present invention will be described below with reference to two embodiments shown in the drawings.

As shown in FIG. 1, a combined cycle plant is constructed by directly connecting a carbon turbine turbine, a generator 2, and a steam turbine 3. An air compressor 4 is directly connected to the front shaft of the gas turbine 1, and the air produced by this air compressor is sent to the combustion hook S1, and the combustion gas is guided to the gas turbine 1 to drive it. . Fi is a composite unit consisting of a gas turbine 1 and a steam turbine 3.
The exhaust heat boiler 6I utilizes the exhaust heat of the gas turbine 1 to create steam.The exhaust gas of the gas turbine I is guided to the exhaust heat boiler 6, and the pressure steam pipe system 7 of the exhaust heat boiler 6 and a low-pressure steam pipe system 8 are introduced into the steam turbine/3 via an artificial valve 9, a pressure steam control valve lO, an inlet valve 11, and a low-pressure steam control valve 12, respectively.

In this case, in a combined cycle plant 62 consisting of a gas turbine 1 and a steam turbine 3, the air compressor 40 is connected to the front shaft of the air compressor 40 via a clutch to start the electric motor. It was directly connected to
The control system is configured to eliminate this starting prime mover and use the steam turbine 3 as the first starting prime mover.

That is, in a steam turbine plant, auxiliary steam spatulas 13 used for #1 or 12 of the steam system used for the steam turbine 3 and 62 used for other purposes are installed side by side.

This auxiliary steam header 136: Steam supply line 14 from other
Two steams are supplied to the tank. The steam from this steam heater 13 is led to the high pressure steam system 70 of the waste heat boiler 6 through the decompression II Is 15 upstream of the artificial valve 9; It is led between the inlet valve l of the system 8 and the low-pressure steam control valve 12.

Next, a method of starting up a combined cycle plant based on the present invention Q4T, which is operated in C2 or more as described above, will be explained. In the lk1 diagram, the steps to start up the plant are as follows: ◎ (1) Use the needle column that does not indicate that the auxiliary steam header 130 pressure is above the specified level.

(A pressure waste steam control valve 10 inlet valve 9. Low pressure steam control valve 1
2 and its inlet valve 11 are fully closed.

(Fully open the stop valve 16 of the assembly auxiliary steam header 13 system.

(4) Steam turbine 3 with only 62M of low pressure regulating valve 12
Warm up a single room by supplying steam to the room.

(When the 51111 machine is completed, the low pressure regulating valve 12 is gradually opened to increase the amount of steam, and the 1K air turn is increased by 30 revolutions. (6) Air pressure - The outlet pressure of the machine 4 is above the specified value. Ward: Natsutomo ignites the combustion engine 5 and uses the combustion gas 1 to increase the output of the gas turbine 1. <0 (Ma) When the shaft rotation speed exceeds the rated value, the stop valve 16 is gradually closed to C. ;Close it, check that the rotation speed does not drop, and then fully close it.

(8) Gradually increase the inlet fuel of Combustion Master 5 and continue to increase the rotation by gas turbine 1, bringing it closer to the rated value by one. The output of the steam turbine 3 is changed from the auxiliary steam header 13 to the steam driven from the waste heat boiler 6 when the output continues to be driven for 52 seconds.

In the embodiment shown in FIG. 1, the auxiliary steam from the steam header 13 is introduced above the low-pressure steam valve 12, but instead of this, the auxiliary steam is introduced into the upstream side of the I:11i + pressure regulating valve lO. It is convenient to configure C2 so that the rotation of the steam turbine 3 is increased by the high pressure regulating valve 10+2, and this can be selected in consideration of the properties of the auxiliary steam source and the characteristics of the steam turbine.

As mentioned above, according to Motoya, the steam turbine is configured to be equipped with an air compressor, a gas turbine, a generator, and a steam turbine, and to supply steam from a waste heat boiler that utilizes the exhaust heat of the gas turbine. At the initial startup of the plant, steam is supplied to the steam turbine 82 from the auxiliary steam header other than the exhaust heat boiler (k, etc.) and the steam system, and after startup is completed, the steam is supplied from the auxiliary steam header to the steam system of the exhaust heat mailer. I: From 1-, which made it possible to switch,
Instead of installing a separate prime mover as in the past, nearby steam sources installed in parallel can be used effectively, resulting in energy savings.

[Brief explanation of the drawing]

The drawing is a configuration diagram showing an example of a plant configuration for carrying out the method for starting up a combined cycle plant of the present invention. Air compressor 5 - Combustor 6... Exhaust heat boiler 7...^ Pressure steam system 8... Low pressure steam system 9 - High pressure steam artificial valve lO
...High pressure steam control valve 11-・Low pressure steam artificial valve 12-
Low pressure steam control valve 13...Auxiliary steam head 14--Steam supply 2-in 15...Reducing pressure desuperheater 16...Auxiliary steam stop valve 17...Check valve

Claims (1)

[Claims] (1) An air pressure system, a gas turbine, a generator, and a steam turbine are connected directly to each other on one axis 6, so that steam is supplied to the steam turbine from an exhaust heat boiler 2 that utilizes the exhaust heat of the gas turbine. °C: In the configured combined cycle plant, at the initial start-up of the plant - steam is supplied to the steam turbine from the auxiliary steam system other than the steam system from Nikaki Netsu Boitz, and after tmm, the steam turbine is driven from the auxiliary steam system. A method for starting a combined cycle plant characterized by switching to a steam system of an exhaust heat boiler (2) Supplying auxiliary steam to a low-pressure steam line C of a steam turbine at the time of initial startup Claim 1. (8) A method for starting a combined cycle plant according to claim 1, characterized by: (8) supplying C2 auxiliary steam to the high-pressure steam system of a steam turbine at initial startup.