JP2960981B2 - Gas turbine plant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine plant having a gas turbine driven by combustion gas in a pressurized fluidized bed.

[0002]

2. Description of the Related Art FIG. 2 shows a pressurized fluidized-bed boiler (Pressurized).
1 is a system diagram of a gas turbine plant including a gas turbine driven by a combustion gas of Fluidized Bed Combustor (hereinafter, referred to as PFBC).

The high-pressure discharge air from the gas turbine air compressor 1 driven by the gas turbine 7 passes through a double pipe 2 containing a PFBC combustion gas pipe 13 to be described later, a chamber 3, and an air shutoff valve 4, and then passes through a PFBC5. Flows into. PFBC5
In this case, the coal 5 'is burned by the high-pressure air, and the generated superheated steam is sent to a steam turbine (not shown).

On the other hand, the combustion gas of the PFBC, which has been heated by the PFBC 5 and has become high temperature, flows into the combustion gas pipe 13, and the gas shutoff valve 6 provided in the pipe 13 and the combustion gas pipe 13 in the double pipe 2. And flows into the gas turbine 7 through the portion to drive the gas turbine 7 to drive the generator 20 and the air compressor 1.

In this type of turbine plant, the PF
BC5 is installed at a position about 100 m away from the gas turbine room. Therefore, the gas turbine cannot be started as it is because of a time delay. For this reason, a start-up combustor 8 to which a branch pipe 21 connected to the double pipe 2 is connected is installed. When the gas turbine is started, the air shutoff valve 4 and the gas shutoff valve 6 are closed, and the branch pipe is closed. Opening the air cutoff valve 9 provided at 21, the supply air from the air compressor 1 is supplied to the starting combustor 8, and at the same time, oil or gas 8 'is supplied as fuel to the combustor 8 and burned. By supplying the combustion gas to the combustion gas pipe 13 on the downstream side of the gas shut-off valve 6, the gas turbine 7 is started.

When the start of the gas turbine 7 is completed, the shutoff valves 4 and 6 are fully opened, the shutoff valve 9 is fully closed, and the operation shifts to the operation of the PFBC 5. In addition, reference numeral 15 denotes a pipe system support.

[0007]

In the above-mentioned conventional gas turbine plant, the distance between the PFBC 5 and the gas shut-off valve 6 placed near the gas turbine 7 is usually as long as about 100 m. When switching to
While the combustion gas of the FBC 5 passes through the combustion gas pipe 13 in a cold state, the temperature of the combustion gas decreases due to heat radiation to the pipe 13.

As a result, the gas temperature at the turbine inlet of the gas turbine 7 decreases, and the output of the gas turbine decreases.
In some cases, 0 caused excessive motoring, tripped, and restarted in some cases.

[0009] The present invention is to solve the above problems in the conventional gas turbine plant.

[0010]

SUMMARY OF THE INVENTION The present invention provides a gas turbine driven by the combustion gas of a pressurized fluidized bed boiler, a generator driven by the gas turbine, and the pressurized fluidized bed boiler driven by the gas turbine. A gas turbine plant comprising: an air compressor that supplies combustion air to a gas turbine; and a starting combustor that supplies combustion gas for starting the gas turbine to a combustion gas pipe from the pressurized fluidized bed boiler to the gas turbine. the supplied combustion air from an air compressor, which is connected at a position near the outlet of the PFBC PFBC boiler into the combustion gas pipe of the boiler combustion <br/> combustion gases for supplying the pilot combustion A vessel was provided.

[0011]

According to the present invention, when the gas turbine is started, when the pilot combustor is operated, the vicinity of the outlet of the pressurized fluidized bed boiler is reduced.
At a nearby location, substantially at the outlet of the pressurized fluidized bed boiler
As a starting point the corresponding position, the combustion gas pipe of a PFBC boiler under cold-over long distances is heated to a suitable temperature by the combustion gases of the pilot combustor. The combustion gas from the pilot combustor merges with the combustion gas from the starting combustor and flows into the gas turbine to start the gas turbine.

[0012] Next, when igniting the PFBC boiler, the combustion gas pipe of a PFBC boiler, Pyro as the
Since the gas is heated to an appropriate temperature by the combustion gas of the cut combustor and the number of cold parts is small, the gas temperature at the gas turbine inlet is kept high throughout the startup.

[0013]

FIG. 1 is a system diagram of an embodiment of the present invention.

In this embodiment, the gas turbine plant shown in FIG. 2 is improved as described below, and the same parts are denoted by the same reference numerals in FIG. 1 as in FIG. 2 and the description thereof is omitted. I do.

A pilot combustor 10 for starting is installed near the PFBC 5, and is connected to a double pipe 2 via a bypass pipe 12 for discharge air branched from the double pipe 2 and an air cutoff valve 11 provided in the pipe 12. The compressed air discharged from the air compressor 1 is sent from the outside air system 2.

The combustion gas pipe 22 of the pilot combustor 10 is connected to a position near the outlet of the pressurized fluidized bed boiler 5 of the combustion gas pipe 13 of the pressurized fluidized bed boiler. The gas cutoff valve 14 is provided upstream of the connection point of the pipe 22. The pilot combustor 10 uses oil or gas 10 'as fuel.

In this embodiment, when the gas turbine 7 is started, the gas shut-off valve 14 and the air shut-off valve 4 are closed, the gas shut-off valve 6, the air shut-off valve 9 and the air shut-off valve 11 are opened, and the combustion air is started. To combustor 8 and pilot combustor 10,
The combustors 8 and 10 are started to perform combustion. The combustion gas of the pilot combustor 10 flows through the combustion gas pipe 22 to a position near the outlet of the pressurized fluidized bed boiler 5 in the combustion gas pipe 13 of the pressurized fluidized bed boiler 5, and the combustion gas of the starting combustor 8. At the same time, the gas flows through the combustion gas pipe 13 and flows into the gas turbine 7 to start the gas turbine 7.

At this time, the combustion gas from the pilot combustor 10 flows into the upper pipe 13 at a position near the outlet of the pressurized fluidized bed boiler 5 in the combustion gas pipe 13 as described above. Therefore, most of the combustion gas pipe 13 over a long distance is heated to an appropriate temperature, and the cold state of the pipe 13 is eliminated.

When the gas turbine 7 starts as described above, the air cutoff valve 4 is opened, the air cutoff valve 9 and the air cutoff valve 11 are sequentially closed, and the gas cutoff valve 14 is opened to open the PFBC.
Ignite 5. Accordingly, the operation of the starting combustor 8 and the operation of the pilot combustor 10 are stopped, the combustion gas of the PFBC 5 is supplied to the gas turbine 7 via the combustion gas pipe 13, and the operation of the gas turbine 7 is continued. At this time, since the combustion gas pipe 13 is heated to an appropriate temperature by the combustion gas of the pilot combustor 10 as described above, the temperature of the combustion gas of the PFBC 5 supplied to the gas turbine 7 is maintained at a high temperature. As a result, the output of the gas turbine 7 does not decrease, and therefore, the generator 20 does not cause excessive motoring and cause a trip.

[0020]

According to the present invention, by lowering the gas temperature at the gas turbine inlet by heating the long-distance PFBC combustion gas pipe by the combustion gas from the pilot combustor, When switching from the start-up combustor to the PFBC, troubles such as motoring of the gas turbine generator do not occur, and the gas turbine can be started smoothly.

[Brief description of the drawings]

FIG. 1 is a system diagram of one embodiment of the present invention.

FIG. 2 is a system diagram of a conventional turbine plant driven by PFBC combustion gas.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air compressor 5 PFBC 7 Gas turbine 8 Starting combustor 10 Pilot combustor 11 Air shutoff valve 12 Bypass pipe of discharge air 13 PFBC combustion gas pipe 14 Gas shutoff valve 20 Generator

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02C 7/26 F02C 3/26 F02C 6/00 F23C 11/02 310

Claims (1)

(57) [Claims] 1. A gas turbine driven by combustion gas of a pressurized fluidized bed boiler, a generator driven by the gas turbine, and air driven by the gas turbine to supply combustion air to the pressurized fluidized bed boiler Compressor,
And in a gas turbine plant having a starting combustor for supplying a starting combustion gas for the gas turbine to a combustion gas pipe from the pressurized fluidized bed boiler to the gas turbine, combustion air is supplied from the air compressor. It is, out of the PFBC boiler into the combustion gas pipe of the PFBC boiler
A gas turbine plant comprising a pilot combustor connected at a position near a mouth to supply combustion gas.