JPH11210496A - Gas turbine fuel control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the ignitability of a gas turbine, and ensure stable combustion during warming-up operation. SOLUTION: A gas turbine control device for controlling the flow rate of fuel in a gas turbine fuel supply system 10 incorporating a fuel flow adjusting valve 12 for feeding fuel into a gas turbine burner 3, is composed of equipment for measuring data relating to the fuel fed into the gas turbine fuel supply system 10, (that is, a fuel flow meter 21, a pressure detector 22, temperature detectors 23a to 23c (23), a fuel component analyzer 24, a fire detector 25) and a valve opening degree controller 30 for determining an opening degree of the fuel flow adjusting valve 12 so as to obtain a present optimum fuel flow rate on the basis of measuring signals from the above-mentioned equipment, and delivering an instruction to the fuel flow adjusting valve 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine fuel control device, and more particularly to a device for controlling fuel supply at the time of ignition and warm-up of a gas turbine.

[0002]

2. Description of the Related Art In a gas turbine, fuel is supplied to a combustor and an atmosphere (oxygen source) from the outside is supplied to the combustor.
Is compressed and compressed by an air compressor to feed the fuel, thereby burning the fuel in the combustor. Therefore, in such a combustion event, it is necessary to appropriately control the flow rate ratio between the fuel and the air. For this reason, in the conventional gas turbine, the fuel flow is controlled based on a predetermined fuel flow command value set in advance so that the gas turbine is ignited and warmed up. After ignition, control is performed to input fuel in accordance with an increase in load.

[0003]

However, in such a conventional gas turbine fuel control system, each of the fuel flow rates when the gas turbine is ignited and when it is warmed up is set to a constant value. There were the following inconveniences.

[0004] For example, in a situation where poor ignition occurs at the time of gas turbine ignition or combustion instability occurs during warm-up operation after ignition, it has been difficult to appropriately control the fuel flow rate. This is because such a situation is not particularly conscious in the conventional fuel control system. For the same reason, at the time of periodic inspection of the gas turbine, the fuel flow control valve is disassembled and inspected and adjusted every time, and very fine setting adjustment is required each time, so that the operation is complicated and the work efficiency is not good.

[0005] LNG (liquefied natural gas:
LPG (liquefied petroleu) as well as liquefied natural gas
When m gas (liquefied petroleum gas) is used as a fuel, the calorific value naturally differs when the country of origin of the fuel changes, because the fuel components also generally differ. However, despite the difference in the calorific value of the used fuel, the conventional method controls all the fuels based on the same fixed fuel flow rate command. It has been difficult to obtain stable combustion.

On the other hand, gas turbines have recently been widely used as combined cycle power generation equipment, and the output of a single unit has been increasing steadily. In particular, since such equipment is expected to operate using a DSS (decision support system), reliable ignition performance based on a power supply command is required. To this end, it is necessary to control the fuel supply more appropriately according to the fuel supplied to the gas turbine, to consider the protection of high-temperature components of the gas turbine, to improve ignitability and to ensure stable combustion during warm-up operation. It becomes important.

An object of the present invention has been made in consideration of such conventional circumstances, and has as its object to improve the ignitability of a gas turbine and to ensure stable combustion during a warm-up operation.

[0008]

In order to achieve the above object, the present inventor makes the fuel flow rate command variable at the time of ignition and warm-up of the gas turbine, so that the actual fuel flow rate is not a constant value as in the conventional example. We paid attention to the configuration that controls based on. Examination of a specific example of the configuration shows that it is relatively easy and inexpensive to construct, for example, by using existing measuring equipment, thereby improving the ignitability of the gas turbine and achieving stable combustion during warm-up operation. Do you get it.

The gas turbine control device according to the present invention has been completed based on such knowledge. Hereinafter, the contents of the problem solving means will be sequentially described.

According to a first aspect of the present invention, there is provided an apparatus for controlling a fuel flow rate of a gas turbine fuel supply system having a fuel flow rate control valve for sending fuel to a gas turbine combustor, wherein fuel is supplied to the gas turbine combustor. Opening degree determining means for determining an opening degree of the fuel flow rate control valve in a state where the fuel flow rate becomes a current optimum fuel flow rate based on information on the fuel when sent, and the fuel flow rate control valve determined by the opening degree determining means. Opening command means for commanding the opening to the fuel flow control valve.

[0011] In the invention described in claim 2, the opening degree determining means includes, as information on the fuel, a flow rate measuring device for measuring a fuel flow rate of the gas turbine fuel supply system, and a fuel measured by the flow rate measuring device. Means for determining an opening degree of the fuel flow control valve in a state where an optimum fuel flow rate is obtained at the time of ignition and warm-up operation of the gas turbine combustor based on the measured flow rate value.

According to the present invention, the fuel flow rate command can be corrected based on the deviation from the actual flow rate based on the fuel flow rate signal,
The originally required opening of the fuel flow control valve can be set, thereby greatly improving ignitability and stable combustion during warm-up.

According to a third aspect of the present invention, the opening degree determining means measures at least one of a combustion temperature of the gas turbine combustor and a gas turbine exhaust gas temperature as the information on the fuel. And the opening degree of the fuel flow control valve in a state where the optimum fuel flow rate is obtained at the time of ignition and warm-up operation of the gas turbine combustor based on the temperature actually measured by the temperature measuring device,
Means for determining within a fuel input range corresponding to a combustion temperature range necessary to protect the gas turbine hot components.

According to the present invention, the actual firing temperature of the combustor or the exhaust gas temperature of the gas turbine at the time of ignition and warm-up is measured, and the fuel flow command at the time of ignition is controlled rather than a constant value. The input fuel can be variably controlled while observing the combustion temperature at the time of warm-up and at the time of warm-up, and the ignitability can be greatly improved.

[0015] In the invention described in claim 4, the opening degree determining means includes, as the information regarding the fuel, at least a combustion temperature of a plurality of combustors constituting the gas turbine combustor and a temperature of each gas turbine exhaust gas. A temperature measuring device for measuring one of them, and a minimum necessary fuel flow rate capable of maintaining a state close to a limit at which the plurality of combustors do not misfire at the time of start-up and warm-up based on a temperature actually measured by the temperature measuring device. Means for determining the opening of the fuel flow control valve in a state where

According to the present invention, the combustion temperature of each of the plurality of combustors or the gas turbine exhaust gas temperature corresponding to each of the combustors is measured, and a state close to the limit at which each combustor does not misfire at the time of ignition and warm-up is measured. To select and adjust the required minimum fuel flow command that can be maintained and control the opening of the fuel flow control valve, the minimum supply fuel can be supplied so as not to misfire while monitoring the combustion temperature of each combustor. It reduces thermal shock, prolongs the life of parts, improves ignitability and provides stable combustion.

According to a fifth aspect of the present invention, the opening degree determining means includes, as the information on the fuel, a fire detector for detecting a fuel ignition state of the gas turbine combustor, and a fuel ignition by the fire detector in advance. Means for determining the opening degree of the fuel flow control valve so as to increase the fuel flow rate when the fuel flow rate is not confirmed within the set time.

According to the present invention, if ignition is not confirmed within the set time, the fuel flow command is increased to a predetermined value, the opening of the fuel flow control valve is controlled to increase, and ignition is performed again. If ignition is not confirmed by the flame detector within the specified time even if ignition is performed, the fuel flow rate command is increased to a predetermined value within the range of allowable thermal shock for the life of the high temperature parts of the combustor, and the fuel flow rate is increased. The ignition can be performed by controlling the opening of the control valve to increase.

In the invention described in claim 6, the opening degree determining means includes, as information on the fuel, a firing temperature and a firing temperature of a plurality of combustors constituting the gas turbine combustor during the warm-up operation of the gas turbine. A monitoring device for monitoring the deviation of at least one of the gas turbine exhaust gases; and a combustion device necessary for protecting the gas turbine high-temperature parts when the monitoring device determines that the gas turbine combustor has an ignition failure or misfire. Means for determining an opening of the fuel flow control valve within a maximum supplyable fuel flow range for protecting the temperature.

According to the present invention, during the warming-up operation of the gas turbine, the deviation of each firing temperature of the gas turbine combustor or the exhaust temperature of the gas turbine corresponding to each combustor is monitored, and poor ignition or unstable combustion occurs. If there is a combustor that has failed, determine the fuel input within the range of the maximum supplyable fuel input to protect the combustion temperature necessary to protect the gas turbine hot parts, and select and adjust the warm-up fuel flow command. In order to control the opening of the fuel flow control valve, ignition is completed, but if some of the combustors become unstable during warm-up operation, if the allowable thermal shock to the life of the combustor high temperature parts is
The warm-up fuel flow command is increased to obtain stable combustion of the combustor.

[0021] In the invention according to claim 7, the opening degree determining means measures and analyzes the component of the fuel sent to the gas turbine combustor as the information on the fuel, and analyzes the analysis result by the measuring and analyzing means. Means for determining an opening degree of the fuel flow control valve in an optimal fuel flow state when the gas turbine combustor is ignited and warmed up based on a calorific value of the fuel and a specific volume thereof.

According to the present invention, the components of the supplied fuel are measured and analyzed, and the fuel flow rate commands at the time of ignition and warm-up of the gas turbine according to the calorific value and specific volume of each fuel are selectively adjusted.
In order to control the opening of the fuel flow control valve, a fuel flow command based on the result of component analysis of the fuel to be used is provided, so that ignitability is improved and stable combustion during warm-up is obtained.

[0023] In the invention described in claim 8, the opening degree determination means includes means for preliminarily holding information relating to the calorific value of each of the plurality of fuels and the specific volume thereof as the information about the fuel, and the information holding means. The opening degree of the fuel flow control valve is determined based on the retained information so that the gas flow rate of the gas turbine combustor is optimal when the gas turbine combustor is ignited and warmed up. Means.

According to the present invention, in a gas turbine for selectively using a plurality of fuels whose calorific value and specific volume of a gas turbine fuel to be used are known in advance, ignition and warm-up are performed in accordance with the selected fuel. In order to select and adjust the fuel flow command and control the opening of the fuel flow control valve, the analysis of the fuel component is not performed, but the fuel flow is determined according to the calorific value and specific volume of each of several types of predetermined fuel. Since the command is corrected, ignitability is improved and stable combustion during warm-up is obtained.

According to the ninth aspect of the present invention, the opening degree determining means holds in advance information on the actual flow rate characteristic curve of the fuel flow control valve as the fuel information, and the information holding means holds the information. Means for determining an opening degree of the fuel flow control valve in a state where an optimum fuel flow rate is obtained when the gas turbine combustor is ignited and warmed up based on the information.

According to the present invention, the fuel flow rate command at the time of ignition and at the time of warm-up is selected and adjusted by using the actual flow rate characteristic curve of the fuel flow rate control valve, and the opening degree of the fuel flow rate control valve is controlled. For the error in the production of the flow control valve, using the actual flow characteristic curve to perform the control taking the error into account, the control with the fuel flow command corrected to improve the ignitability and Stable combustion during warm-up is obtained.

[0027] In the tenth aspect of the present invention, the opening degree determination means includes means for preliminarily holding, as the information about the fuel, information about the deviation of the fuel flow control valve over time, and information holding means. Means for determining an opening degree of the fuel flow control valve in a state where an optimum fuel flow rate is obtained when the gas turbine combustor is ignited and warmed up based on the held information.

According to the present invention, taking into account the deviation due to the aging of the fuel flow control valve, the actual fuel flow measurement value is prioritized, and the fuel flow commands at the time of ignition and warm-up are selectively adjusted, and the fuel flow is controlled. In order to control the control valve opening, considering the deviation due to the aging of the fuel flow control valve, by giving priority to the actual flow signal of the actual fuel flow meter, more appropriate fuel flow control can be performed, Improved ignitability and stable combustion during warm-up are obtained.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas turbine fuel control device according to the present invention will be described below with reference to FIG.

The gas turbine equipment shown in FIG.
The combustion gas to be supplied to the gas turbine 2, which is the power source, is generated by the gas turbine combustor 3. The combustor 3 includes a compressed air from an air compressor 4 coaxially connected to the gas turbine 2 and a gas turbine fuel supply system 1.
Mix and burn with LNG or LPG fuel from 0,
This combustion gas is supplied into the gas turbine 2.

The gas turbine fuel supply system 10 sends fuel from a fuel supply source (not shown) to the gas turbine combustor 3, and is provided on a fuel flow path 11 communicatively connected to the combustor 3. Various valves, that is, a fuel flow control valve 12, a fuel cutoff valve 13, and a fuel emergency cutoff valve 14 are provided at positions.

Such a gas turbine facility is provided with a gas turbine fuel control device 20 for variably controlling the fuel flow rate of the gas turbine fuel supply system 10.

The gas turbine fuel control device 20 includes various measuring devices, that is, (1) as shown in the figure: a fuel flow meter 21, a pressure detector 22... 22, a temperature detector 23a, and a fuel component on the fuel flow path 11. Analyzer 24, (2): Combustor 3
(3): temperature detector 23b on the combustion gas discharge side of the combustor 11, and (4): temperature detector 23c on the gas discharge side of the gas turbine 2, and these measuring devices 21 ... A valve opening control unit 30 that controls the valve opening of the fuel flow control valve 12 based on at least one of the measurement signals D1 to D13 from the control unit 25 or information about a preset flow characteristic of the fuel flow control valve 12; It has.

The valve opening control section 30 is constituted by a microcomputer, for example, and has a CPU 31 and a CPU 31 as shown in FIG.
A fuel flow control algorithm 32 that defines a program to be executed by the CPU 31 and a reference table 33 to be referred to by the CPU 31 are provided. This control unit 30
The CPU 31 executes the fuel flow rate control algorithm 32 as shown in FIG.
, D13,..., The opening of the fuel flow control valve 12 in an optimum fuel flow state is determined, and the command S1 is supplied to the fuel flow control valve 12 via an interface (not shown).

Here, a setting example of the fuel flow control algorithm 32 will be described.

The fuel from the gas turbine fuel supply system 10 is mixed with the compressed air from the air compressor 4 in an optimum mixing ratio (mixing ratio of fuel and air = fuel / air ratio) in a gas turbine combustor. 3 need to be supplied. Therefore, a command S1 for determining the opening of the fuel flow control valve 12 is determined according to the following mode.

1): A deviation from the set value is obtained based on the actual measured value D3 of the fuel flow rate by the fuel flow meter 21, and the opening of the fuel flow control valve 12 is determined so as to correct the deviation. FIG. 3 shows an example of the processing flow in this case. Here, when the actual measured value D3 of the fuel flow rate is inputted in Step St1, a deviation between the measured value D3 and the set value of the optimal flow rate is calculated in Step St2, and the actual optimal flow rate is calculated in Step St3 based on the calculation result. The opening degree of the fuel flow control valve 12 in the following condition is obtained, and the command S1 is output in step St4.

2): Based on the measured value D12 of the combustion temperature of the combustor by the temperature detector 23b and the measured value D13 of the exhaust gas temperature of the gas turbine by the temperature detector 23c, the fuel flow control valve 12 is set to the optimum fuel flow rate. Determine the opening. The gist of the processing flow in this case is also substantially the same as described above. At this time, control is performed within the required minimum fuel (mixing ratio of fuel and air = minimum fuel-air ratio) that does not cause the combustor 3 to misfire, and within the maximum supplyable fuel input range for protecting the gas turbine hot parts. I do.

3): Fire detector 2 when the gas turbine is ignited
If the ignition cannot be confirmed within a predetermined time based on the signal D11 by 5, the opening of the fuel flow rate control valve 12 is controlled so that the fuel flow rate is increased to a predetermined value. The gist of the processing flow in this case is substantially the same as described above.

4): Based on the analysis data D4 such as the calorific value and specific volume of the fuel by the fuel component analyzer 24, the opening of the fuel flow control valve 12 in the state of the optimum fuel flow is determined. The gist of the processing flow in this case is substantially the same as described above.

5): Control is performed in consideration of the change in the flow characteristic curve or the aging characteristic of the fuel flow control valve 12 and the calorific value and specific volume of the fuel used. These data are set and held in the reference table 33 in advance, and can be referred to by the CPU 31 as needed.

Therefore, according to this embodiment, the fuel flow rate command at the time of ignition and warm-up of the gas turbine can be corrected and set in real time as a variable value instead of a constant value as in the conventional example, and can be adjusted according to the turbine operation status. It is possible to control the fuel flow with high accuracy, thereby improving the ignitability at the time of ignition of the gas turbine and the unstable combustion state at the time of warming up, and greatly improving the reliability of the gas turbine operation. .

In this embodiment, the valve opening control section is constituted by a microcomputer. However, the present invention is not limited to this, and a digital signal may be used without departing from the principle of the present invention. Needless to say, it may be constituted by a circuit or an analog circuit.

[0044]

As described above, according to the present invention, the ignitability at the time of ignition of the gas turbine and the unstable combustion state at the time of warm-up can be improved, and the reliability in the operation of the gas turbine is greatly improved. become. This effect can be exerted more particularly when applied to a combined cycle power generation facility where DSS operation is expected.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing the overall configuration of a gas turbine fuel control device according to the present invention.

FIG. 2 is a schematic block diagram illustrating main functions of a valve opening control unit.

FIG. 3 is a schematic flowchart illustrating a processing example of a gas turbine fuel control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Generator 2 Gas turbine 3 Gas turbine combustor 4 Air compressor 10 Gas turbine fuel supply system 11 Fuel flow path 12 Fuel flow control valve 13 Fuel cutoff valve 14 Fuel emergency cutoff valve 20 Gas turbine fuel control device 21 Fuel flow meter 22 Pressure detector 23a, 23b, 23c Temperature detector 24 Fuel component analyzer 25 Fire detector 30 Valve opening control unit 31 CPU 32 Fuel flow control algorithm 33 Reference table

Claims (10)

[Claims] 1. An apparatus for controlling a fuel flow rate of a gas turbine fuel supply system having a fuel flow rate control valve for feeding fuel to a gas turbine combustor, wherein the fuel is supplied to the gas turbine combustor when the fuel is sent to the gas turbine combustor. Opening determination means for determining the opening of the fuel flow control valve in a state where the current fuel flow is optimal based on the information regarding the fuel flow rate, and the opening of the fuel flow control valve determined by the opening determination means is determined by the fuel flow rate. A gas turbine fuel control device comprising: an opening command means for commanding a control valve. 2. The invention according to claim 1, wherein the opening degree determining means measures, as the information on the fuel, a flow rate measuring device for measuring a fuel flow rate of the gas turbine fuel supply system, and the flow rate measuring device measures the fuel flow rate. Means for determining an opening degree of the fuel flow control valve in a state where an optimum fuel flow rate is obtained at the time of ignition and warm-up operation of the gas turbine combustor based on a measured fuel flow rate value. 3. The invention according to claim 1, wherein the opening degree determining means measures, as the information regarding the fuel, at least one of a combustion temperature of the gas turbine combustor and a gas turbine exhaust gas temperature. A measuring device, based on an actual temperature value measured by the temperature measuring device, the opening degree of the fuel flow rate control valve in the state of the optimal fuel flow rate at the time of ignition and warm-up operation of the gas turbine combustor, Means for determining within a fuel input range corresponding to a combustion temperature range necessary to protect the turbine hot components. 4. The invention according to claim 1, wherein the opening degree determining means includes, as the information on the fuel, each combustion temperature of a plurality of combustors constituting the gas turbine combustor and each gas turbine exhaust gas temperature. A temperature measuring device for measuring at least one of the above, and a minimum necessary for maintaining a state close to a limit at which the plurality of combustors do not misfire at the time of startup and warm-up based on an actual temperature measured by the temperature measuring device. Means for determining an opening of the fuel flow control valve in a state of a fuel flow. 5. The invention according to claim 1, wherein the opening degree determining means detects a fuel ignition state of the gas turbine combustor as information on the fuel, and a fuel ignition by the fire detector. Means for determining the opening degree of the fuel flow control valve so as to increase the fuel flow rate when is not confirmed within a preset time. 6. The invention according to claim 1, wherein the opening degree determination means includes, as the information on the fuel, firing each of a plurality of combustors constituting the gas turbine combustor during a warm-up operation of the gas turbine. A monitoring device for monitoring the deviation of at least one of the temperature and the exhaust gas of each gas turbine, and necessary for protecting the hot parts of the gas turbine when the ignition failure or misfire of the gas turbine combustor is confirmed by the monitoring device. Means for determining the degree of opening of the fuel flow control valve within the maximum supplyable fuel flow range for maintaining a proper combustion temperature. 7. The invention according to claim 1, wherein the opening degree determination means measures and analyzes a component of the fuel sent to the gas turbine combustor as the information on the fuel, and analyzes the information by the measurement and analysis means. Means for determining an opening of the fuel flow control valve in an optimal fuel flow state at the time of ignition and warm-up of the gas turbine combustor based on the calorific value of the fuel and the specific volume of the result. Gas turbine fuel control device. 8. The invention according to claim 1, wherein the opening degree determining means holds, in advance, information relating to the heat value of each of the plurality of fuels and the specific volume thereof as the information related to the fuel, and the information holding means. The opening degree of the fuel flow control valve in a state in which the gas flow rate of the gas turbine combustor is optimum when the gas turbine combustor is ignited and warmed up based on the information held by the means. A gas turbine fuel control device comprising: 9. The invention according to claim 1, wherein the opening degree determination means includes means for preliminarily retaining, as the information relating to the fuel, information relating to an actual machine flow characteristic curve of the fuel flow control valve, and the information retaining means. Means for determining an opening degree of the fuel flow rate control valve in a state where an optimum fuel flow rate is obtained when the gas turbine combustor is ignited and warmed up based on the information held. 10. The invention according to claim 1, wherein the opening degree determining means holds in advance, as the information on the fuel, information on a deviation of the fuel flow control valve during use over time, and holds this information. Means for determining an opening degree of the fuel flow control valve in a state where an optimum fuel flow rate is obtained when the gas turbine combustor is ignited and warmed up based on information held by the means.