JP3605138B2 - Ignition switching method for gas turbine device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to ignition switching method of the gas turbine equipment having two or more series of combustors that use different fuels.
[0002]
[Prior art]
Various kinds of different fuels are used in the gas turbine device, and they may be used in a single system or in a plurality of systems.
FIG. 3 is a schematic system diagram of a gas turbine device having one series of combustors. A combustor 5 is installed in a connecting pipe 3 that connects the air compressor 1 and the gas turbine 2.
[0003]
In the gas turbine device having such a single-system combustor 5, the combustor 5 is ignited in a low rotation range, and after rated operation of the gas turbine 2, the fuel to the combustor 5 is cut off at no load and at the rated rotation speed. Then, the gas turbine 2 is stopped.
[0004]
FIG. 4 is a transition diagram of a fuel flow rate and a rotation speed from ignition to fuel cutoff of a gas turbine having a single-line combustor.
As shown in FIG. 4, the rotation speed at the time of ignition of the gas turbine gradually increases from the point E, and the gas turbine is operated at the rated rotation speed F point. Meanwhile, the fuel is gradually increased from ignition to the rated speed.
After operation at the rated speed, the fuel to the combustor is shut off at the no-load rated speed G, and the gas turbine is stopped.
[0005]
FIG. 5 is a transition diagram of the control valve opening and the fuel flow rate in both combustors when the combustor is switched in a gas turbine device having two series of combustors in parallel between the air compressor and the gas turbine.
The control valve opening of both combustors is increased or decreased linearly so that the sum of the calorific values of the fuel to both combustors is the same, and the fuel is switched while the gas turbine output is constant.
[0006]
[Problems to be solved by the invention]
In fuel switching in a gas turbine apparatus having two series of combustors arranged in parallel between an air compressor and a gas turbine, a transient change in gas turbine output is not required, or a fuel piping system is used. It is necessary to ignite the combustor that ignites at the time of switching under a high pressure in order to prevent the occurrence of damages due to the pressure wave.
[0007]
However, if the combustor is ignited at a high pressure, the load fluctuates greatly at the time of ignition due to the difference in the calorific value of the fuel, the difference in the pressure loss of the fuel piping system, or the complicated operation of both control valves. There are points.
[0008]
The present invention relates to a gas turbine device having an air compressor, a gas turbine, and a plurality of combustors installed in parallel between the air compressor and the gas turbine, wherein a combustor to be switched without causing a load change. It is an object of the present invention to provide an ignition switching method capable of igniting and switching a combustor.
[0010]
[Means and Actions for Solving the Problems]
The present invention provides an air compressor, a gas turbine, and a method for switching ignition of a gas turbine device having a plurality of combustors installed in parallel between the air compressor and the gas turbine. A blow-off system provided with a blow-off valve provided on the downstream side of each combustor, and a control valve provided on each connection pipe connecting each combustor and the gas turbine to control the amount of flowing gas. Is adopted.
[0011]
In the ignition switching method for the gas turbine device according to the present invention, the air discharge system with the air release valve is installed in each of the wakes of the two series of combustors. Open the blow-off valve and close the gas turbine with the control valve to ignite under low pressure.After ignition, gradually close the blow-off valve and raise the pressure, then the control valve between the combustor and the gas turbine. When the combustor is switched by opening the combustor, the combustor can be switched under the same combustion conditions as the other combustor during combustion, that is, the fuel can be switched.
[0012]
Therefore, according to the ignition switching method of the gas turbine device of the present invention, when switching the combustor, it is possible to prevent the load fluctuation, which is a problem at the time of ignition under a high pressure, and to generate a pressure wave causing vibration. Can be prevented.
[0013]
The switching of the combustor in the gas turbine device according to the present invention described above is effectively performed in the following procedure.
That is, in switching the combustor, the process of opening and closing the blow-off valve and the control valve provided in the downstream of the combustor for switching and burning, respectively, and igniting, The process of closing and opening the valve and the control valve, respectively, and the step of gradually reducing and shutting off the fuel flow to the burning combustor before switching, and gradually increasing the fuel flow of the ignited combustor before switching. The process up to quantification is performed in this order.
[0014]
If the combustor is switched through the above process, the combustion of the combustor is stabilized by the blown air, then the blown air is cut off, and the pressure of the combustor rises to back up the combustor that is burning ahead I will do it. Then, the combustion in the combustor that is burning first is gradually reduced, and the combustion in the combustor that has been ignited later is gradually increased, so that the switching of the combustor is completed smoothly.
[0015]
In the ignition switching method described above, the process of closing the blow-off valve and opening the control valve after igniting the combustor that burns after the switching is performed while gradually increasing the fuel flow rate to the combustor. This is preferable because the combustion in the combustor is increased and the backup for the previously combusted combustor is gradually increased, so that the combustor can be switched smoothly after the pressure of the combustor increases.
[0016]
【Example】
Hereinafter, an embodiment of the ignition switch method for a gas turbine equipment according to the present invention will be described with reference to FIG.
FIG. 1 is a schematic system diagram of a gas turbine device having two series of combustors installed in parallel between an air compressor and a gas turbine 2.
In FIG. 1, branch pipes 4A and 4B are connected in parallel to a connecting pipe 3 connecting the air compressor 1 and the gas turbine 2, and combustors 5A and 5B are installed in the branch pipes 4A and 4B. ing.
[0017]
Downstream of the combustors 5A and 5B of the parallel branch pipes 4A and 4B, exhaust pipes 6A and 6B are respectively piped, and the exhaust pipes 6A and 6B are respectively provided with exhaust valves 7A. , 7B are installed to form two air discharge systems.
FIG. 2 is a transition diagram of the number of revolutions of the gas turbine 2 at the time of combustion switching of the combustors 5A and 5B, the fuel flow to the combustors 5A and 5B, and the amount of blown air in each blowing system.
[0018]
The switching of the combustor in the gas turbine device shown in FIG. 1 is performed as follows.
Assume that the combustor 5A is ignited first, the fuel flow rate increases, the rotational speed increases, the rated rotational speed / load is reached, and the operation is continued. This state is switched to the combustion of the combustor 5B. First, while the operation by the combustor 5A is continued, the combustor 5B is ignited after opening the blow-off valve 7B to start blowing (at this time, the control valve 8B is closed). The pressure is gradually increased, and the blow-off valve 7B is closed, and after the pressure rises, the control valve 8B is opened and the blow-off is completely shut off.
[0019]
When the pressure of the combustor 5B rises in this way to back up the combustor 5A, the fuel flow rate of the combustor 5A is gradually reduced, and the switching from the combustor 5A to 5B is completed at the point C shown in FIG. .
When the gas turbine 2 is stopped, the operation of the combustor 5B → 5A is performed again in the same manner as described above in order to return the combustor 5A to the state at the time of starting, and then, as shown in FIG. The fuel to the combustor 5A is shut off and the gas turbine 2 is stopped.
[0020]
【The invention's effect】
As described above, according to the ignition switching method for the gas turbine device of the present invention, when switching the combustion of a plurality of combustors installed in parallel between the air compressor and the gas turbine, the switching after each combustor is performed. The ignition switching can be performed by using the air discharge system provided in each of the streams so as not to cause a load variation at the time of ignition.
[0021]
In addition, according to the ignition switching method of the gas turbine device according to the present invention, the switching of the combustor is performed smoothly while preventing the load fluctuation, so that the influence such as the secondary damage due to the pressure wave, which has conventionally been a problem, is also prevented. Therefore, the effect of improving the reliability of the gas turbine is great.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram of a gas turbine device having two series of combustors to which an ignition switching method according to an embodiment of the present invention is applied .
FIG. 2 is a transition diagram showing changes in the number of revolutions of the gas turbine, the fuel flow rate in each combustor, and the amount of blown air when switching between two series of combustors in the gas turbine device shown in FIG. 1;
FIG. 3 is a schematic system diagram of a conventional gas turbine device having a single-line combustor.
FIG. 4 is a transition diagram of a rotation speed and a fuel flow rate in a conventional gas turbine device having one series of combustors.
FIG. 5 is a transition diagram of a control valve opening degree and a fuel flow rate when a combustor is switched in a conventional gas turbine device having two series of combustors.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air compressor 2 Gas turbine 3 Connecting pipe 4A, 4B Branch pipe 5A, 5B Combustor 6A, 6B Outlet pipe 7A, 7B Outlet valve 8A, 8B Control valve

Claims (2)

In a gas turbine device having an air compressor, a gas turbine, and a plurality of combustors disposed in parallel between the air compressor and the gas turbine, air is provided on a downstream side of each of the combustors. An exhaust system equipped with a valve, and a control valve for controlling the amount of flowing gas provided in each connection pipe connecting each of the combustors and the gas turbine is provided , and the control valve is provided downstream of the combustor for switching and burning. The process of opening and closing the blow-off valve and the control valve, respectively, to ignite, the process of closing and opening the blow-off valve and the control valve, respectively, after the ignition, and the combustion during combustion before switching. ignition switching method of a gas turbine device, characterized in that the fuel flow rate of the combustor ignited with blocking gradually decreases the fuel flow to vessel gradually increased and a process leading up to a predetermined amount. After ignition to the combustor for burning after switching, a process of the control valve and the blow-off valve in the closed to the open, performed while gradually increasing the fuel flow to the combustor, the gas turbine apparatus of claim 1, wherein Ignition switching method.

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