JP5485023B2 - Gas turbine fuel supply pressure control mechanism, gas turbine, and gas turbine fuel supply pressure control method - Google Patents

Description

The present invention relates to a gas fuel supply system for a gas turbine, and more particularly to a gas turbine fuel supply pressure control mechanism, a gas turbine, and a gas turbine fuel supply pressure control method .

A gas turbine is a device having a compressor, a combustor, and a turbine as main components.
In general, in a gas fuel supply system that supplies gas fuel to a combustor of a gas turbine, a gas fuel supply system for supplying a desired fuel flow rate to the combustor of the gas turbine while maintaining the gas fuel supplied by the compressor at a constant pressure. A control mechanism is required.
Since such a gas turbine supplies gas fuel to the combustor, it is necessary to pressurize the gas fuel to a certain value or more in consideration of pressure loss due to valves, piping, fuel nozzles, and the like.

As a gas turbine fuel control mechanism, a configuration using a flow rate control valve that controls the flow rate of gas fuel and a pressure control valve that controls the pressure of gas fuel upstream of the flow rate control valve is known.
In such a gas turbine fuel control mechanism, in order to supply gas fuel into the combustor of the gas turbine, it is necessary to ensure a pressure higher than the cabin pressure (pressure in the combustor) as the discharge pressure of the fuel nozzle. Therefore, the outlet pressure of the pressure control valve is set to be equal to or higher than at least the discharge pressure of the fuel nozzle plus the pressure loss in the downstream flow path of the pressure control valve.

The conventional gas turbine employs a fixed value from the no-load state to the base load state as the gas fuel supply pressure setting value. However, when the outside air conditions (temperature, pressure, etc.) around the gas turbine change, the physical property values (density, etc.) of the compressed air supplied from the compressor into the combustor also change in the gas turbine.
For this reason, for example, as shown in FIG. 11, when the outside air condition changes, that is, when the casing pressure that is the base of the actually required supply pressure varies according to the outside air condition, If the difference between the pressure (actual requirement indicated by the solid line in the figure) and the set value of the supply pressure (current requirement indicated by the broken line in the figure) becomes large, the operable range is more than necessary. It will be narrowed.

  Therefore, in Patent Document 1 below, as shown in FIG. 12, the set value of the gas fuel supply pressure is made a function of the outside air condition and the compressor pressure ratio, and the operating range is expanded compared to the case of a fixed value. We propose a method that can do this. In FIG. 12, the broken line display indicates a method using an existing pressure schedule and the solid line display indicates a function, and the operable range is increased in the hatched region.

JP 2007-218254 A

However, in the technique described in Patent Document 1 described above, the compressor pressure ratio that determines the set value of the gas fuel supply pressure (the compressor pressure ratio used for the function that calculates the set value of the gas fuel supply pressure) is detected. A delay problem is expected.
That is, with the method of directly feeding back the measured pressure value, there is a possibility that the set value of the gas fuel supply pressure cannot be accurately calculated online. In such a case, the gas fuel may not be pressurized to a necessary pressure. In the worst case, the fuel is not sufficiently supplied to the combustor, and normal operation of the gas turbine cannot be maintained.

Against this background, in gas turbines that use gas fuel, the effect of changes in conditions such as outside temperature on the operating range is reduced compared to when a fixed value is used for the gas fuel supply pressure setting value. Thus, it is desired to develop a gas turbine fuel supply pressure control mechanism, a gas turbine, and a gas turbine fuel supply pressure control method capable of expanding the operable range.
The present invention has been made to solve the above-described problems, and the object of the present invention is to control the supply pressure of gas turbine fuel that can expand the operating range more than when the supply pressure of gas fuel is fixed. It is an object to provide a mechanism, a gas turbine, and a gas turbine fuel supply pressure control method .

In order to solve the above problems, the present invention employs the following means.
A gas turbine fuel supply pressure control mechanism according to the present invention includes a flow rate control valve that controls a fuel flow rate downstream of a pressure control valve that sets gas fuel to a desired fuel supply pressure and supplies the fuel flow to a fuel nozzle of a combustor. A gas turbine fuel supply pressure control mechanism that is used in a gas fuel supply system of a gas turbine and that adjusts the opening degree of the pressure control valve to vary the fuel supply pressure, and compresses the combustor A control unit having a characteristic map of a compressor for supplying air and an opening degree command calculation unit of the pressure control valve is provided, and the control unit includes an inlet guide vane opening degree command value, a gas turbine rotation The estimated pressure in the combustor is given based on the number and the input value of the outside air condition, and the opening command calculation unit calculates the fuel supply pressure calculated based on the estimated pressure in the passenger compartment. Set value And outputs the opening command of the corresponding pressure regulating valve, and performs outlet pressure control by the opening adjustment of the pressure regulating valve.

According to such a gas turbine fuel supply pressure control mechanism , a control unit including a characteristic map of a compressor for supplying compressed air to the combustor and an opening degree command calculation unit for the pressure control valve is provided. The characteristic map gives an estimated pressure in the combustor based on the inlet guide vane opening command value, the gas turbine speed and the input value of the outside air condition, and the opening command calculation unit The output of the pressure control valve opening command corresponding to the set value of the fuel supply pressure calculated based on the estimated value of the chamber pressure is output, and the outlet pressure is controlled by adjusting the opening of the pressure control valve. Thus, the outlet pressure control of the pressure control valve corresponding to is performed, and the operable range of the gas turbine can be expanded as compared with the case where a fixed value is used for the fuel supply pressure.
In addition, by using the inlet guide vane opening command value and the gas turbine speed, it is possible to accurately calculate the set value of the fuel supply pressure online without worrying about detection delay, which is a concern with pressure sensors with a large time constant. Can do.

  In the above invention, the input value for estimating the passenger compartment pressure estimated value is the inlet guide vane opening command value, the gas turbine rotational speed, and the outside air condition until the gas turbine rotational speed reaches a rated rotational speed. It is preferable to use the inlet guide vane opening command value and the outside air condition after the gas turbine rotation speed reaches the rated rotation speed, and thus, after the gas turbine rotation speed reaches the rated rotation speed, The set value of the fuel supply pressure can be calculated without feedback from the sensor, except for outside air conditions in which the detection delay does not have a significant effect. That is, the adverse effect due to the detection delay by the sensor is removed, and the supply pressure control of the gas turbine fuel can be performed more accurately.

  In the above-mentioned invention, it is preferable to add a temperature measurement value of the gas fuel to an input value for estimating the passenger compartment pressure estimation value, whereby a fuel temperature that can be a disturbance in estimating a necessary pressure applied to the gas fuel. Thus, the set value of the fuel supply pressure can be calculated more accurately.

  In the above invention, it is preferable to add the fuel flow rate command value of the gas fuel to the input value for estimating the passenger compartment pressure estimated value, and thereby the fuel flow rate command value varies due to a load variation of the gas turbine, The responsiveness of the pressure control can be improved by correcting the fuel flow rate command value.

  In the above invention, it is preferable to add a fuel flow rate measurement value of the gas fuel to an input value for estimating the passenger compartment pressure estimation value. The responsiveness of the pressure control can be improved by correcting the fuel flow rate measurement value.

  In the above-mentioned invention, it is preferable to add the temperature measurement value of the gas fuel and the fuel flow rate command value to the input value for estimating the passenger compartment pressure estimation value. If the fuel flow rate command value fluctuates due to gas turbine load fluctuations, etc., the pressure control response can be obtained by correcting the fuel flow rate command value. Can be improved.

  In the above-mentioned invention, it is preferable to add a temperature measurement value and a fuel flow rate measurement value of the gas fuel to an input value for estimating the passenger compartment pressure estimation value. If the fuel flow command value fluctuates due to gas turbine load fluctuations, etc., the pressure control response can be corrected by correcting the fuel flow measurement value. Can be improved.

In the above invention, the control unit is one or more selected in the characteristic map from the input value group of the estimated cabin pressure value, the required gas turbine output value, the fuel flow rate command value of the gas fuel, and the fuel flow rate measurement value. It is preferable that the vehicle interior pressure is estimated based on the input value and the input value of the outside air condition, and is given to the opening degree command calculation unit of the pressure control valve, whereby a fixed value is set for the fuel supply pressure. Compared with the case of using, the operable range of the gas turbine can be expanded.

  In the above invention, the control unit may perform differential pressure control between the inlet pressure and the outlet pressure of the flow control valve by adjusting the opening of the pressure control valve. Similar to the outlet pressure control by adjustment, the outlet pressure control of the pressure control valve corresponding to the fluctuation of the passenger compartment pressure is implemented, and the operating range of the gas turbine is reduced compared to the case of using a fixed value. Can be enlarged.

A gas turbine according to the present invention includes a compressor that introduces and compresses air, a combustor that generates combustion gas by burning fuel with air supplied from the compressor, and a supply of combustion gas from the combustor. And a control unit that performs control by the supply pressure control mechanism for the gas turbine fuel according to any one of claims 1 to 9.

According to such a gas turbine, since the control part which performs control by the supply pressure control mechanism of the gas turbine fuel according to any one of claims 1 to 9 is provided, the pressure adjustment corresponding to the fluctuation of the passenger compartment pressure The valve outlet pressure control is implemented, and the operable range of the gas turbine can be expanded as compared with the case where a fixed value is used for the fuel supply pressure.
In addition, by using the inlet guide vane opening command value and the gas turbine speed, it is possible to accurately calculate the set value of the fuel supply pressure online without worrying about detection delay, which is a concern with pressure sensors with a large time constant. Can do.
Further, the gas turbine fuel supply pressure control method according to the present invention controls the flow rate of fuel supplied to the fuel nozzle of the combustor by controlling the fuel flow rate downstream of the pressure control valve that sets the gas fuel to a desired fuel supply pressure. A gas turbine fuel supply pressure control method that is used in a gas fuel supply system of a gas turbine having a valve and adjusts an opening degree of the pressure control valve to vary the fuel supply pressure, the combustor A control unit having a characteristic map of a compressor for supplying compressed air to the pressure control valve and an opening command calculation unit of the pressure control valve, the control unit having an opening command value of the inlet guide vane, The fuel given by the casing pressure estimated value obtained by estimating the pressure in the combustor based on the input values of the gas turbine rotational speed and the outside air condition, and calculated by the opening degree command calculation unit based on the estimated casing pressure Supply pressure And outputs the opening command of the pressure regulating valve corresponding to the set value, is characterized in carrying out the outlet pressure control by the opening adjustment of the pressure regulating valve.
According to such a gas turbine fuel supply pressure control method, the outlet pressure control of the pressure control valve corresponding to the fluctuation of the passenger compartment pressure is performed, compared with the case where a fixed value is used for the fuel supply pressure. Thus, the operable range of the gas turbine can be expanded. And by using the inlet guide vane opening command value and the gas turbine speed, there is no fear of detection delay that is a concern with a pressure sensor with a large time constant, and the fuel supply pressure set value is accurately calculated online. Can be controlled.

  According to the present invention described above, in a gas turbine that uses gas fuel, compared to the case where a fixed value is adopted as the gas fuel supply pressure setting value, the influence of changes in conditions such as outside air temperature on the operable range is affected. It is possible to reduce the operating range.

1 is a system diagram showing an embodiment of a gas turbine fuel supply pressure control mechanism according to the present invention. FIG. It is a schematic structure figure showing one embodiment of a gas turbine concerning the present invention. It is a flowchart which shows the 1st modification of the supply pressure control mechanism of the gas turbine fuel which concerns on this invention. It is a systematic diagram which shows the 2nd modification of the supply pressure control mechanism of the gas turbine fuel which concerns on this invention. It is a systematic diagram which shows the 3rd modification of the supply pressure control mechanism of the gas turbine fuel which concerns on this invention. It is a systematic diagram which shows the 4th modification of the supply pressure control mechanism of the gas turbine fuel which concerns on this invention. It is a systematic diagram showing the 5th modification of the supply pressure control mechanism of the gas turbine fuel concerning the present invention. It is a systematic diagram which shows the 6th modification of the supply pressure control mechanism of the gas turbine fuel which concerns on this invention. It is a systematic diagram which shows the 7th modification of the supply pressure control mechanism of the gas turbine fuel which concerns on this invention. It is a systematic diagram which shows the 8th modification of the supply pressure control mechanism of the gas turbine fuel which concerns on this invention. Regarding the base load gas fuel supply pressure requirement, the difference between the actually required supply pressure (actual requirement indicated by the solid line in the figure) and the set value of the supply pressure (current requirement indicated by the broken line in the figure) It is explanatory drawing which shows the condition which became large. It is explanatory drawing which shows expansion of the driving | operation possible width | variety by a prior art.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a gas turbine fuel supply pressure control mechanism, a gas turbine, and a gas turbine fuel supply pressure control method according to the present invention will be described with reference to the drawings.
FIG. 2 is a block diagram showing a schematic configuration of the gas turbine GT. The combustor F combusts the gas fuel, the turbine T that rotates by expanding the combustion gas supplied from the combustor F, and compresses the air. The compressor C is provided as a main component, and various operation controls are performed by the control unit 10.

  The gas turbine plant GT supplies gas fuel from a fuel supply source 1 of a gas fuel supply source to pilot nozzles and main nozzles (hereinafter collectively referred to as “fuel nozzles”) in the combustor F. A gas fuel supply system 5 provided with a pressure control valve 3 and a flow rate control valve 4 in the middle is provided. The gas fuel supply system 5 is a control mechanism for giving a desired fuel flow rate to the combustor F of the gas turbine GT while maintaining the gas fuel pumped by a fuel compressor (not shown) at a desired pressure. , A pressure regulating valve 3 and a flow regulating valve 4 arranged in series are provided.

The pressure control valve 3 arranged on the upstream side sets the gas fuel to a desired fuel supply pressure, and the flow rate control valve 4 on the downstream side controls the flow rate of the gas fuel and supplies it to the fuel nozzle of the combustor F. The fuel nozzle includes a pilot nozzle (not shown) and a plurality of main nozzles (not shown) arranged at intervals on the outer periphery of the pilot nozzle.
And in this embodiment, the supply pressure control of the gas turbine fuel which makes the fuel supply pressure variable by adjusting the opening degree of the pressure control valve 3 is performed by the control unit 10 that performs various operation controls of the gas turbine GT.

FIG. 1 is a system diagram showing an example of a gas turbine fuel supply pressure control mechanism . A fuel pipe 2 for introducing gas fuel from a fuel supply source such as the fuel supply source 1 branches according to the number of fuel nozzles N installed in the combustor F (n in the example shown from Na to Nn). That is, the fuel branch pipes 2a to 2n branched for each of the pilot nozzle and the plurality of main nozzles are arranged in parallel. When a plurality of combustors F are provided, the same fuel pipe 2 and fuel branch pipes 2a to 2n are provided for each combustor F.
In addition, the code | symbol 6 in a figure is a pressure gauge which detects the outlet pressure of the pressure control valve 3, and inputs it into the control part 10. FIG.

The control unit 10 outputs a characteristic map (compressor characteristic map) 11 of the compressor C that supplies compressed air to the combustor F and an opening degree command signal S that controls the opening degree of the pressure control valve 3. A command calculation unit 12 is provided.
The compressor characteristic map 11 is a map related to the characteristics of the compressor C constituting the gas turbine GT. The compressor characteristic map 11 gives an estimated value of the cabin pressure obtained by estimating the pressure in the combustor F (the cabin pressure) based on the input value input to the control unit 10. The input values in this case are the inlet guide vane opening command value 21 provided in the compressor C, the gas turbine rotational speed 22 in which the rotational speed of the gas turbine GT is detected, and the surrounding environment where the gas turbine GT is installed. An outside air condition 23 in which the outside air temperature or pressure, that is, the temperature or pressure of the air compressed by the compressor C is detected is used.

The opening degree command calculation unit 12 calculates a set value of the fuel supply pressure based on the estimated value of the cabin pressure given from the compressor characteristic map 11, and generates an opening degree command signal S corresponding to the set value. Output to the pressure control valve 3.
Accordingly, the control unit 10 calculates the opening degree command value by using the compressor characteristic map 11 based on the inlet guide vane opening degree command value 21, the gas turbine rotational speed 22 and the outside air condition 23 input values. The opening command calculation unit 12 calculates a set value of the fuel supply pressure based on the estimated value of the cabin pressure, and calculates an opening command signal from the opening of the pressure control valve 3 corresponding to the set value. Since S is generated and output, the outlet pressure can be controlled by adjusting the opening of the pressure control valve 3. That is, the outlet pressure of the pressure control valve 3 detected by the pressure gauge 6 changes according to the input values of the inlet guide vane opening command value 21, the gas turbine rotational speed 22, and the outside air condition 23.

In this way, the control unit 10 that controls the supply pressure of the gas turbine fuel gives the estimated value of the cabin pressure in which the compressor characteristic map 11 estimates the pressure in the combustor F based on the input value, and calculates the opening degree command. The vehicle outputs the opening command of the pressure control valve 3 in accordance with the set value of the fuel supply pressure calculated based on the estimated value of the passenger compartment pressure, and performs outlet pressure control by adjusting the opening of the pressure control valve 3. The outlet pressure control of the pressure control valve 3 corresponding to the fluctuation of the chamber pressure is performed. That is, since the opening degree of the pressure control valve 3 is controlled so as to obtain an optimum outlet pressure according to the vehicle compartment pressure, it is actually necessary as compared with the prior art using a fixed value for the fuel supply pressure. Deviation between the supply pressure and the set value of the supply pressure is eliminated or suppressed, and as a result, the operable range of the gas turbine GT can be expanded.
Further, since the inlet guide vane opening command value 21 and the gas turbine rotational speed 22 are used, there is no fear of detection delay which has been a concern with a pressure sensor having a large time constant. Can be calculated accurately.

FIG. 3 is a flowchart showing a first modification of the gas turbine fuel supply pressure control mechanism described above.
In this supply pressure control mechanism , the input guide vane opening command value is used as an input value for estimating the passenger compartment pressure estimated value until the gas turbine speed 22 reaches the rated speed, as in the above-described embodiment. 21, a gas turbine rotational speed 22 and an outside air condition 23 are used. However, after the gas turbine speed 22 reaches the rated speed, only the inlet guide vane opening command value 21 and the outside air condition 23 are used, and the gas turbine speed 22 is not used. Such a supply pressure control mechanism is also applicable to other modified examples described later.

That is, when starting at the first step S1, the gas turbine speed 22 is detected at the next step S2.
In the next step S3, it is determined whether or not the detected value of the gas turbine rotational speed 22 is equal to or less than a predetermined value. In this case, the predetermined value is the rated rotational speed, and if the detected value of the gas turbine rotational speed 22 does not reach the rated rotational speed is “YES”, the routine proceeds to step S4 and the vehicle compartment pressure based on the compressor characteristic map 11 Estimate There are three types of input values used in this case: an inlet guide vane opening command value 21, a gas turbine speed 22 and an outside air condition 23.

On the other hand, if it is determined in step S3 that the detected value of the gas turbine rotational speed 22 has reached the rated rotational speed is “NO”, the process proceeds to step S5 to estimate the cabin pressure based on the compressor characteristic map 11. Do. There are two types of input values used in this case: the inlet guide vane opening command value 21 and the outside air condition 23.
If such control is performed, the passenger compartment pressure is estimated by a process that differs depending on the gas turbine rotational speed 22, and therefore, after the gas turbine GT reaches the rated rotational speed, the outside air condition 23 in which the detection delay does not have a large influence is set. Except for this, it is possible to calculate the set value of the fuel supply pressure without using feedback from a sensor or the like that detects the rotational speed. That is, after the gas turbine GT reaches the rated rotational speed, more accurate gas turbine fuel supply pressure control can be performed by removing the adverse effects caused by the sensor detection delay.

FIG. 4 is a system diagram showing a second modification of the gas turbine fuel supply pressure control mechanism described above. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
The control unit 10A employed in this modification adds a fuel temperature 24, which is a temperature measurement value of gas fuel, to an input value for estimating the passenger compartment pressure estimation value. The fuel temperature 24 is obtained by measuring the temperature of the supplied gas fuel upstream of the pressure control valve 3.

  That is, the fuel temperature 24 is a value that can be a disturbance when the required pressure applied to the gas fuel is estimated. Therefore, when the actual fuel temperature 24 is measured and corrected, the disturbance is eliminated and the fuel supply pressure is set. The value can be calculated more accurately.

FIG. 5 is a system diagram showing a third modification of the gas turbine fuel supply pressure control mechanism described above. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
The control unit 10B employed in this modification adds the fuel flow rate command value 25 of gas fuel to the input value for estimating the passenger compartment pressure estimated value. The fuel flow rate command value 25 is a value that varies depending on the operating condition of the gas turbine GT. Therefore, when the fuel flow rate command value 25 fluctuates due to the load fluctuation of the gas turbine GT or the like, the fuel flow rate command value 25 is added to the input value to correct the opening degree adjustment of the pressure control valve 3, thereby controlling the pressure control. Responsiveness is improved.

FIG. 6 is a system diagram showing a fourth modification of the gas turbine fuel supply pressure control mechanism described above. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
The control unit 10C employed in this modified example adds a fuel flow measurement value 26 of gas fuel to the input value for estimating the passenger compartment pressure estimated value instead of the fuel flow rate command value 25 of the third modified example. . The fuel flow rate measurement value 26 is a value obtained by measuring the fuel flow rate actually consumed by the gas turbine GT. Therefore, when the fuel flow rate measurement value 26 fluctuates due to a load fluctuation of the gas turbine GT or the like, the fuel flow rate measurement value 26 is added to the input value to correct the opening degree adjustment of the pressure control valve 3, thereby controlling the pressure control. Responsiveness is improved.

FIG. 7 is a system diagram showing a fifth modification of the gas turbine fuel supply pressure control mechanism described above. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
The control unit 10D employed in this modified example adds the fuel temperature 24 of the second modified example and the fuel flow rate command value 25 of the third modified example to the input value for estimating the passenger compartment pressure estimated value. Accordingly, the fuel temperature 24 can be corrected by estimating the required pressure to be applied to the gas fuel to calculate a more accurate set value of the fuel supply pressure, and the fuel flow rate command value 25 varies due to a load variation of the gas turbine GT. In this case, the responsiveness of the pressure control can be improved by correcting the fuel flow rate command value.

FIG. 8 is a system diagram showing a sixth modification of the gas turbine fuel supply pressure control mechanism described above. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
The control unit 10E employed in this modification example adds the fuel temperature 24 of the second modification example and the fuel flow rate measurement value 26 of the fourth modification example to the input value for estimating the passenger compartment pressure estimation value. That is, instead of the fuel flow rate command value 25 of the fifth modification, a fuel flow rate measurement value 26 of gas fuel is adopted. Even if such supply pressure control is performed, it is possible to calculate the more accurate set value of the fuel supply pressure by correcting the fuel temperature 24 to the estimation of the required pressure applied to the gas fuel, and to change the load of the gas turbine GT, etc. When the fuel flow measurement value 26 fluctuates due to the above, it is possible to improve the responsiveness of the pressure control by performing correction based on the fuel flow command value.

FIG. 9 is a system diagram showing a seventh modification of the gas turbine fuel supply pressure control mechanism described above. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
The control unit 10F employed in this modification performs differential pressure control between the inlet pressure and the outlet pressure of the flow rate adjusting valve 4 by adjusting the opening degree of the pressure adjusting valve 3.

That is, a differential pressure gauge 7 for measuring the differential pressure ΔP on the upstream side and the downstream side of the flow rate control valve 4 is provided, and this measured value is input to the control unit 10E. Then, similarly to the outlet pressure control of the pressure control valve 3 described above, the opening command of the pressure control valve 3 corresponding to the set value of the fuel supply pressure calculated by the opening command calculation unit 12 based on the estimated value of the passenger compartment pressure. And the differential pressure control is performed so that the differential pressure ΔP becomes a desired value by adjusting the opening degree of the pressure control valve 3.
As a result, similar to the outlet pressure control by adjusting the opening degree of the pressure control valve 3, the outlet pressure control of the pressure control valve 3 corresponding to the fluctuation of the passenger compartment pressure is performed, and a fixed value is used. In comparison, the operable range of the gas turbine GT can be expanded.

FIG. 10 is a system diagram showing an eighth modification of the gas turbine fuel supply pressure control mechanism described above. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In the case of the control unit 10G employed in this modified example, the opening degree command calculation unit 12 includes an input value selection group 27 including an estimated cabin pressure value, a gas turbine output request value, a fuel flow rate command value, and a fuel flow rate measurement value. Then, an opening degree command of the pressure control valve 3 corresponding to the set value of the fuel supply pressure calculated based on the input value selected at least one from the input value selection group 27 is output.

That is, in the illustrated control mechanism example, instead of the inlet guide vane opening command value 21 and the gas turbine rotational speed 22, at least one is selected from the input value selection group 27, or a plurality is selected and combined. Is used for calculating the opening degree command of the pressure control valve 3 together with the outside air condition 23.
By performing such supply pressure control, the operable range of the gas turbine GT can be expanded as compared to the case where a fixed value is used for the fuel supply pressure, as in the above-described embodiment.
In the illustrated control mechanism example, differential pressure control similar to that of the seventh modification is performed, but outlet pressure control by adjusting the opening of the pressure control valve 3 may be performed.

  As described above, the gas turbine GT according to the present embodiment includes the compressor C that introduces and compresses air, and the combustor F that generates combustion gas by burning gas fuel with the air supplied from the compressor C. And the turbine T that receives the supply of combustion gas from the combustor F, and the control units 10 and 10A to 10G of the above-described embodiments and modifications, the pressure control valve corresponding to the fluctuation of the vehicle compartment pressure As a result, the operable range of the gas turbine GT can be expanded as compared with the case where a fixed value is used for the fuel supply pressure.

In addition, by using the inlet guide vane opening command value 21 and the gas turbine rotational speed 22, there is no fear of detection delay that is a concern with a pressure sensor having a large time constant, and the fuel supply pressure setting value is accurately calculated online. can do.
In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary, it can change suitably.

2 Piping 3 Pressure control valve 4 Flow control valve 5 Gas fuel supply system 10, 10A to 10G Control unit 11 Compressor characteristic map 12 Opening command calculation unit 21 Inlet guide vane opening command value 22 Gas turbine rotational speed 23 Outside air condition 24 Fuel temperature 25 Fuel flow command value 26 Fuel flow measurement value 27 Input value selection group GT Gas turbine F Combustor T Turbine C Compressor

Claims (11)

It is used for a gas fuel supply system of a gas turbine that includes a flow rate adjusting valve that controls a fuel flow rate and supplies it to a fuel nozzle of a combustor on the downstream side of a pressure adjusting valve that sets gas fuel to a desired fuel supply pressure. A gas turbine fuel supply pressure control mechanism that adjusts the opening of the pressure control valve to vary the fuel supply pressure;
A control unit including a characteristic map of a compressor that supplies compressed air to the combustor, and an opening degree command calculation unit of the pressure control valve;
The control unit gives an estimated cabin pressure value obtained by estimating the pressure in the combustor based on the inlet guide vane opening command value, the gas turbine rotation speed, and the input value of the outside air condition in the characteristic map. The degree command calculation unit outputs an opening degree command of the pressure control valve corresponding to the set value of the fuel supply pressure calculated based on the estimated value of the cabin pressure, and the outlet pressure by adjusting the opening degree of the pressure control valve A gas turbine fuel supply pressure control mechanism characterized by performing control. The input value for estimating the passenger compartment pressure estimated value is determined by using the opening command value of the inlet guide vane, the gas turbine rotational speed, and the outside air condition until the gas turbine rotational speed reaches a rated rotational speed. 2. The gas turbine fuel supply pressure control mechanism according to claim 1, wherein an opening command value of the inlet guide vane and the outside air condition are used after the turbine speed reaches a rated speed. The gas turbine fuel supply pressure control mechanism according to claim 1, wherein a temperature measurement value of the gas fuel is added to an input value for estimating the casing pressure estimation value. 3. The gas turbine fuel supply pressure control mechanism according to claim 1, wherein a fuel flow rate command value of the gas fuel is added to an input value for estimating the casing pressure estimation value. 3. The gas turbine fuel supply pressure control mechanism according to claim 1, wherein a fuel flow rate measurement value of the gas fuel is added to an input value for estimating the casing pressure estimation value. 3. The gas turbine fuel supply pressure control mechanism according to claim 1, wherein a temperature measurement value and a fuel flow rate command value of the gas fuel are added to an input value for estimating the casing pressure estimation value. 3. The gas turbine fuel supply pressure control mechanism according to claim 1, wherein a temperature measurement value and a fuel flow rate measurement value of the gas fuel are added to an input value for estimating the passenger compartment pressure estimation value. The control unit has one or more input values selected from the input value group of the estimated cabin pressure value, the gas turbine output request value, the fuel flow rate command value and the fuel flow rate measurement value of the gas fuel, and 2. The gas turbine fuel supply pressure control mechanism according to claim 1, wherein the interior pressure of the vehicle interior is estimated based on an input value of the outside air condition and supplied to an opening degree command calculation unit of the pressure control valve. . The gas turbine according to any one of claims 1 to 8, wherein the control unit performs differential pressure control between an inlet pressure and an outlet pressure of the flow rate control valve by adjusting an opening degree of the pressure control valve. Fuel supply pressure control mechanism . A compressor that introduces and compresses air, a combustor that burns fuel with air supplied from the compressor to generate combustion gas, a turbine that receives supply of combustion gas from the combustor, and A gas turbine comprising: a control unit that performs control by a supply pressure control mechanism for the gas turbine fuel according to any one of items 1 to 9. It is used for a gas fuel supply system of a gas turbine that includes a flow rate adjusting valve that controls a fuel flow rate and supplies it to a fuel nozzle of a combustor on the downstream side of a pressure adjusting valve that sets gas fuel to a desired fuel supply pressure. A gas turbine fuel supply pressure control method for adjusting the opening of the pressure control valve to vary the fuel supply pressure,
A control unit including a characteristic map of a compressor that supplies compressed air to the combustor, and an opening degree command calculation unit of the pressure control valve;
The control unit gives an estimated cabin pressure value obtained by estimating the pressure in the combustor based on the inlet guide vane opening command value, the gas turbine rotation speed, and the input value of the outside air condition in the characteristic map. The degree command calculation unit outputs an opening degree command of the pressure control valve corresponding to the set value of the fuel supply pressure calculated based on the estimated value of the cabin pressure, and the outlet pressure by adjusting the opening degree of the pressure control valve A gas turbine fuel supply pressure control method characterized by performing control .

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