KR20190057548A - Gas turbine for improving performance at part-load and control method thereof - Google Patents

Abstract

The present invention relates to a gas turbine capable of optimizing efficiency at the same output point by adjusting the angle of an inlet guide vane (IGV) and exhaust gas temperature (EGT) at the same time according to the efficiency of an engine after reaching a target load, and a control method thereof. According to the present invention, a method for controlling a gas turbine is provided, and the gas turbine comprises: a casing; a compressor disposed in the casing, and for compressing air to a high pressure by inducting the air; a plurality of combustors for combustion by mixing fuel with the air compressed by the compressor; a turbine for producing electricity while rotating a plurality of turbine blades using high temperature and high pressure combustion gas discharged from the combustor; and the IGV provided in an inlet of the compressor and angle-adjustably coupled to the casing. The method for controlling a gas turbine comprises: a load command step for commanding a target load; a target load reaching step for controlling the angle of the IGV and the amount of fuel supplied to the combustor to reach the target load; a concentration determining step for determining the concentration of NOx and CO after reaching the target load; and a second angle controlling step for controlling the angle of the IGV according to the engine efficiency when the concentration, determined in the concentration determining step, does not exceed a limit value.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a gas turbine capable of improving partial load performance and a control method thereof.

The present invention relates to a gas turbine capable of improving partial load performance and a control method thereof, and more particularly, to a gas turbine capable of improving partial load performance and, more particularly, to an exhaust gas temperature To a gas turbine capable of optimizing efficiency at the same output point and a control method thereof.

Generally, a turbine is a machine that converts the energy of a fluid such as water, gas, steam, etc. into mechanical work. It usually plantes several feathers or wings on the circumference of a rotating body and emits vapor or gas to it. Turbine type machines that rotate are called turbines.

Examples of such turbines include a hydraulic turbine that utilizes the energy of water at high places, a steam turbine that utilizes the energy of the steam, an air turbine that uses the energy of high-pressure compressed air, a gas that utilizes the energy of high- Turbines and the like.

BACKGROUND ART Generally, a gas turbine is a type of internal combustion engine that converts thermal energy to mechanical energy by injecting a high-temperature and high-pressure combustion gas generated by mixing fuel into air compressed at a high pressure in a compressor and rotating the turbine.

Since these gas turbines have no reciprocating mechanism such as piston of 4-stroke engine, there is no mutual friction part like piston-cylinder, consumption of lubricating oil is extremely small, amplitude characteristic which is characteristic of reciprocating machine is greatly reduced, There are advantages.

The compressor is provided with a plurality of variable guide vanes on the casing so as to adjust the inflow amount of the outside air. The variable vane precisely controls the amount of inflow air to provide starting stability and protects the compressor from pulsation during start and stop, thereby improving turbine efficiency.

At this time, the turbine outlet temperature, i.e., the exhaust gas temperature, is a parameter that can be used to control the operation of the gas turbine and protect the gas turbine during operation. The variable vane, in particular, the variable inlet vane located at the inlet of the compressor IGV) can be adjusted in angle by the exhaust gas temperature.

That is, conventionally, the angle of the IGV was adjusted according to the exhaust gas temperature so as to control the amount of the inflow air so as not to exceed the maximum turbine outlet temperature.

However, there is a problem that the maximum efficiency operation is difficult by operating only the IGV angle determined according to the exhaust gas temperature, and the method for increasing the partial load performance is limited.

It is an object of the present invention to provide a gas turbine and its control method capable of optimizing the efficiency at the same output point by adjusting the angle of the IGV according to the engine efficiency after reaching the target load simultaneously with the exhaust gas temperature (EGT).

In order to solve the above problem, the present invention not only adjusts the angle of the IGV to the target load in accordance with the exhaust gas temperature (EGT), that is, limits the maximum EGT, but also increases the angle of the IGV according to the engine efficiency So that the maximum efficiency at the target load can be obtained.

According to a first aspect of the present invention, there is provided a combustor comprising: a casing; a compressor disposed in the casing for sucking air and compressing the air to a high pressure; a combustor for combusting the air compressed by the compressor with fuel, An IGV (Inlet Guide Vane) provided at an inlet of the compressor and coupled to the casing so as to be adjustable in angle, a turbine for generating electricity by rotating a plurality of turbine blades using high temperature and high pressure combustion gas discharged from the combustor, And a control unit for controlling the angle of the IGV, wherein the control unit includes: a first angle control unit for controlling an angle of the IGV so as not to exceed a maximum exhaust gas temperature (EGT) until a target load is reached; A concentration determination unit for determining the concentration of oxides (NOx) and carbon monoxide (CO); and a concentration determination unit And a second angle control section for controlling the angle of the IGV according to the engine efficiency when the engine is not operated.

Wherein the first angle control unit maintains the angle of the IGV at a minimum angle when the maximum exhaust gas temperature is not reached and increases the amount of air flowing into the compressor when the maximum exhaust gas temperature is reached, The angle can be adjusted.

At this time, the minimum angle of the IGV may be -50 °.

Further, the limit values of the NOx and CO may be 15 ppm and 10 ppm, respectively.

The second angle control unit may include an angle changing unit for changing the angle of the IGV by a predetermined angle, and an efficiency evaluating unit for evaluating the engine efficiency each time the angle changing unit changes the angle.

At this time, the angle changing unit may change the angle of the IGV by 1 DEG.

Also, the angle changing unit may change the angle of the IGV by 1 DEG in different directions, compare the evaluated efficiencies, and further change the angle by 1 DEG in a direction of increasing efficiency.

Wherein the second angle control unit further changes the angle of the IGV by the angle changing unit when the efficiency evaluated by the efficiency evaluation unit becomes higher than the efficiency before the change after the angle of the IGV is changed by the angle changing unit And the angle of the IGV can be restored to the angle before the change when the pre-change efficiency is lowered.

The maximum exhaust gas temperature (EGT) may be 640 캜.

The fuel control unit may further include a fuel adjusting unit for adjusting a supply amount of fuel supplied to the combustor, wherein when the angle of the IGV is controlled by the first angle control unit and the second angle control unit, The supply amount of the fuel can be adjusted so that it can be reached and maintained.

A combustor disposed in the casing for mixing the air compressed by the compressor with the fuel and for combusting the air; a combustor for combusting the air compressed by the compressor; 1. A gas turbine comprising: a turbine which rotates a plurality of turbine blades using high-temperature, high-pressure combustion gas to produce electric power; and an IGV (Inlet Guide Vane) provided at an inlet of the compressor and connected to the casing in an angle- A target load reaching step of controlling an amount of fuel supplied to the combustor and an angle of the IGV so as to reach the target load; A concentration determination step of determining the concentration of nitrogen oxides (NOx) and carbon monoxide (CO) And a second angle control step of controlling the angle of the IGV in accordance with the engine efficiency when the temperature does not exceed the limit value.

At this time, the target load reaching step may include a first angle controlling step of controlling the angle of the IGV so as not to exceed the maximum exhaust gas temperature (EGT) until the target load is reached.

Wherein the first angle control step includes the steps of: maintaining the angle of the IGV at a minimum angle when the maximum exhaust gas temperature is not reached; and increasing the amount of air flowing into the compressor when the maximum exhaust gas temperature is reached, The angle can be controlled.

At this time, the minimum angle of the IGV may be -50 °.

Further, the limit values of the NOx and CO may be 15 ppm and 10 ppm, respectively.

Also, the second angle control step may change the angle of the IGV by a predetermined angle, and may evaluate the engine efficiency at each change to control the angle of the IGV with the highest efficiency.

At this time, the second angle control step may change the angle of the IGV by 1 DEG.

The second angle control step may change the angle of the IGV by 1 DEG in different directions, compare the evaluated efficiencies, and further change the angle by 1 DEG in a direction in which the efficiency increases.

The maximum exhaust gas temperature (EGT) may be 640 캜.

The method may further include a fuel supply adjusting step for adjusting a supply amount of the fuel so as to maintain the target load when the load is changed as the angle of the IGV is changed by the second angle control step.

According to the present invention, not only the maximum EGT is limited and the angle of the IGV is adjusted to the target load, but the maximum efficiency in the target load can be obtained by further adjusting the angle of the IGV according to the engine efficiency even after reaching the target load .

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a sectional view showing a schematic structure of a gas turbine according to an embodiment of the present invention;
Figure 2 is a cross-sectional view of a portion of the compressor of Figure 1;
3 is a cross-sectional view taken at AA in Fig.
4 is a flowchart sequentially illustrating a method of controlling a gas turbine according to an embodiment of the present invention;

Hereinafter, preferred embodiments of a gas turbine and a control method thereof capable of improving partial load performance of the present invention will be described with reference to FIGS. 1 to 4 attached hereto.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative, But are merely illustrative of the elements recited in the claims.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification. Throughout the specification, when an element is referred to as " comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Fig. 1 is a cross-sectional view showing a schematic structure of a gas turbine according to an embodiment of the present invention, Fig. 2 is a cross-sectional view schematically showing a portion of the compressor of Fig. 1, Fig. 3 is a cross- 4 is a flowchart sequentially illustrating a control method of a gas turbine according to an embodiment of the present invention.

Hereinafter, a gas turbine according to an embodiment of the present invention will be described with reference to Fig.

A gas turbine 1 according to an embodiment of the present invention includes a casing 100 and a compressor 200 disposed in the casing 100 for compressing the air by sucking air to a high pressure, A plurality of combustors 300 for mixing the air compressed by the burner 300 with the fuel and burning the plurality of turbine blades using the high temperature and high pressure combustion gas discharged from the combustor 300, And a turbine (400).

The casing 100 includes a compressor casing 102 in which the compressor 200 is accommodated, a combustor casing 103 in which the combustor 300 is accommodated, and a turbine casing 104 in which the turbine 400 is accommodated can do. However, the present invention is not limited thereto, and the compressor casing, the combustor casing, and the turbine casing may be integrally formed.

Here, the compressor casing 102, the combustor casing 103, and the turbine casing 104 may be sequentially arranged from the upstream side to the downstream side in the fluid flow direction.

A rotor (central shaft) 500 is rotatably installed in the casing 100. A generator (not shown) is interlocked with the rotor 500 to generate electricity. A turbine (not shown) And a diffuser for discharging the combustion gas passing through the combustion chamber 400 may be provided.

The rotor 500 includes a compressor rotor disk 520 housed in the compressor casing 102, a turbine rotor disk 540 housed in the turbine casing 104, A torque tube 530 for connecting the rotor disk 520 and the turbine rotor disk 540, a tie rod 540 for fastening the compressor rotor disk 520, the torque tube 530 and the turbine rotor disk 540 550 and a fixing nut 560. [

The compressor rotor disk 520 may be formed in a plurality (for example, 14 pieces), and the plurality of compressor rotor disks 520 may be arranged along the axial direction of the rotor 500. That is, the compressor rotor disk 520 may be formed in multiple stages.

Each of the compressor rotor discs 520 is formed in a substantially disc shape, and a compressor blade coupling slot, which is coupled with a compressor blade 220 to be described later, may be formed in an outer circumferential portion thereof.

The turbine rotor disk 540 may be formed similarly to the compressor rotor disk 520. That is, a plurality of the turbine rotor discs 540 may be formed, and a plurality of the turbine rotor discs 540 may be arranged along the axial direction of the rotor 500. That is, the turbine rotor disk 540 may be formed in multiple stages.

Each of the turbine rotor discs 540 may be formed in a substantially disc shape, and a turbine blade coupling slot may be formed in an outer circumferential portion of the turbine rotor disk 540 to be coupled to a turbine blade 420 described later.

The torque tube 530 is a torque transmitting member that transmits the rotational force of the turbine rotor disk 540 to the compressor rotor disk 520. The torque tube 530 includes one end of the torque tube 530 and the other end of the plurality of compressor rotor disks 520, And the other end of the plurality of turbine rotor discs 540 is positioned at the most upstream end of the plurality of turbine rotor discs 540 in the flow direction of the combustion gas. Each of the torque tube 530 and the turbine rotor disk 540 has a protrusion formed at one end and the other end of the torque tube 530. Grooves for engaging the protrusions are formed in the compressor rotor disk 520 and the turbine rotor disk 540, (530) relative to the compressor rotor disk (520) and the turbine rotor disk (540) can be prevented.

The torque tube 530 may be formed in the shape of a hollow cylinder so that the air supplied from the compressor 200 flows through the torque tube 530 and flows into the turbine 400.

At this time, the torque tube 530 is formed strongly against deformation and distortion due to characteristics of a gas turbine which is continuously operated for a long time, and can be easily assembled and disassembled for easy maintenance.

The tie rod 550 is formed to penetrate a plurality of the compressor rotor discs 520, the torque tube 530 and the plurality of the turbine rotor discs 540, And the other end of the plurality of turbine rotor discs 540 is located at the most downstream end of the plurality of turbine rotor discs 540 in the flow direction of the combustion gas, Protrudes to the opposite side of the compressor 200 and can be fastened to the fixing nut 560.

The fixing nut 560 presses the turbine rotor disk 540 located at the most downstream end toward the compressor 200 and rotates the compressor rotor disk 520 located at the most upstream end and the compressor rotor disk 520 located at the most downstream end The plurality of compressor rotor discs 520, the torque tube 530 and the plurality of turbine rotor discs 540 are arranged in the axial direction of the rotor 500 Lt; / RTI > Accordingly, axial movement and relative rotation of the plurality of compressor rotor discs 520, the torque tube 530, and the plurality of turbine rotor discs 540 can be prevented.

Meanwhile, in the present embodiment, one tie rod is formed to penetrate through the center portions of the plurality of compressor rotor disks, the torque tube, and the plurality of turbine rotor disks, but is not limited thereto. That is, separate tie rods may be provided on the compressor side and the turbine side, respectively, or a plurality of tie rods may be disposed radially along the circumferential direction, or a combination thereof may be used.

Both ends of the rotor 500 according to this configuration are rotatably supported by bearings, and one end of the rotor 500 can be connected to the drive shaft of the generator.

The compressor 200 includes a compressor blade 220 rotated together with the rotor 500 and a compressor vane 240 installed in the casing 100 to align the flow of air flowing into the compressor blade 220, . ≪ / RTI >

The plurality of compressor blades (220) are formed in a plurality of stages along the axial direction of the rotor (500), and the plurality of compressor blades (220) And may be formed radially along the rotation direction of the rotor 500.

The root portion 220a of the compressor blade 220 is coupled to the compressor blade coupling slot of the compressor rotor disk 520 and the root portion 220a is positioned such that the compressor blade 220 is coupled to the compressor blade coupling slot The rotor 500 may be formed in a fir-tree shape to prevent the rotor 500 from being detached from the rotor 500 in the radial direction of rotation.

At this time, the compressor blade coupling slot may be formed in the form of a fir so as to correspond to the root portion 220a of the compressor blade.

In this embodiment, the compressor blade root portion 220a and the compressor blade coupling slot are formed in the form of a fir tree, but are not limited thereto and may be formed in a dovetail shape or the like. Alternatively, the compressor blades may be fastened to the compressor rotor disk using fasteners other than those described above, such as keys or bolts.

Here, the compressor rotor disk 520 and the compressor blade 220 are usually combined in a tangential type or an axial type. In this embodiment, the compressor blade root 220a Is inserted into the compressor blade coupling slot along the axial direction of the rotor 500 as described above. Accordingly, a plurality of the compressor blade coupling slots according to the present embodiment may be formed, and a plurality of the compressor blade coupling slots may be radially arranged along the circumferential direction of the compressor rotor disk 520.

The plurality of compressor vanes 240 may be formed in a plurality of stages, and the plurality of compressor vanes 240 may be formed in a plurality of stages along the axial direction of the rotor 500. Here, the compressor vanes 240 and the compressor blades 220 may be alternately arranged along the air flow direction.

In addition, a plurality of the compressor vanes 240 may be radially formed at each stage along the rotating direction of the rotor 500.

At this time, a part of the plurality of compressor vanes 240 corresponds to a variable guide vanes (not shown) coupled to the casing 100 so as to adjust the inflow amount of the air flowing into the compressor 200 can do.

The variable vane may be adjusted in various operating conditions, for example, between an open state and a closed state at the start and stop of the gas turbine to increase or decrease the inflow amount of air introduced into the compressor 200, It is possible to precisely control the inflow amount of the air to provide start stability and to protect the pulsation of the compressor 200 when starting and stopping, thereby improving turbine efficiency.

2, the variable vane corresponds to the first to fourth compressor vanes of the plurality of compressor vanes 240, and the compressor vanes after the fifth compressor vanes correspond to the casing 100, respectively. Hereinafter, the compressor vanes located at the first stage, that is, the compressor vanes provided at the inlet of the compressor 200 are referred to as IGV (Inlet Guide Vane) 241, and the compressor vanes located at the second stage to fourth stage are referred to as two- Stage variable vane 242, a three-stage variable vane 243, and a four-stage variable vane 244.

However, the present invention is not limited thereto, and it is needless to say that a variable vane having four or more stages may be formed.

Accordingly, the IGV 241, the one-stage compressor blade 221, the two-stage variable vane 242, the two-stage compressor blade 222, A three-stage variable vane 243, a three-stage compressor blade 223 and the four-stage variable vane 244 are arranged in order.

The IGV 241 and the second-stage to fourth-stage variable vanes 242, 243 and 244 are connected to the casing 100 by spindles 261, 262, 263 and 264, respectively, and drive units 281, 282, 283 and 284 are connected to the spindles 261, 262, 263 and 264 so as to rotate the spindle, the angles of the IGV 241 and the second to fourth variable vanes 242, 243 and 244 Lt; / RTI >

However, the present invention is not limited thereto, and any structure may be used as long as the IGV 241 and the second-stage to fourth-stage variable vanes 242, 243, and 244 are angularly coupled to the casing 100.

The driving units 281, 282, 283, and 284 may include actuators using electricity, hydraulic pressure, compressed air, or the like, and may be formed in various manners as long as they are driven.

3, the IGV 241 and the second-stage to fourth-stage variable vanes 242, 243, and 244 are formed of a common airfoil including a leading edge and a trailing edge 262, 263, and 264, and is rotatable about an axis of each of the spindles 261, 262, 263, and 264 and is adjustable in angle.

In FIG. 3, the IGV 241 is shown as being in a minimum angular state, that is, a closed state, in which the amount of air flowing into the compressor 200 can be minimized. At this time, the IGV 241 forms -50 degrees with respect to the direction in which the air flows to the compressor 200, that is, the axial direction of the rotor 500.

The IGV 241 is rotatable about the axis of the spindle 261 by the driving unit 281 so that the IGV 241 can rotate in the open state of the compressor 200 to maximize the amount of air flowing into the compressor 200. [ Lt; / RTI > In the open state, the IGV 241 is disposed in parallel to the direction in which air flows to the compressor 200, that is, the axial direction of the rotor 500.

The IGV 241 may be adjusted at any angle between the closed and open states, and the second-stage to fourth-stage variable vanes 242, 243, 244 may be adjusted as well.

The gas turbine of the present invention includes a control unit 600 for controlling the angle of the IGV 241. The control unit 600 controls the angle of the IGV 241 by controlling the driving unit 281 Can be adjusted.

The control unit 600 not only controls the angle of the IGV 241 to the target load in accordance with the exhaust gas temperature EGT, that is, limits the maximum exhaust gas temperature EGT, The angle of the IGV 241 is further adjusted to obtain the maximum efficiency at the target load.

The control unit 600 and its control method will be described in detail below.

The combustor 300 mixes and combusts the air introduced from the compressor 200 with the fuel to produce a high-temperature high-temperature high-pressure combustion gas. In an equal-pressure combustion process, the combustor 300 and the turbine And may be formed to raise the gas temperature.

Specifically, a plurality of the combustors 300 may be formed, and a plurality of the combustors 300 may be arranged in the combustor casing along the rotational direction of the rotor 500.

In addition, each of the combustors 300 includes a liner into which air compressed in the compressor 200 flows, a burner that injects and burns fuel into the air flowing into the liner, and a combustion gas generated in the burner into the turbine And may include a guiding transition piece.

The liner may include a flame tube that forms a combustion chamber, and a flow sleeve that surrounds the flame tube and forms an annular space.

The burner includes a fuel injection nozzle formed at a front end side of the liner so as to inject fuel into the air introduced into the combustion chamber and an ignition plug formed in a wall portion of the liner so that fuel and air mixed in the combustion chamber are ignited .

The transition piece may be formed so that the outer wall portion of the transition piece is cooled by the air supplied from the compressor so that the transition piece is not damaged by the high temperature of the combustion gas.

That is, the transition piece may have a cooling hole for injecting air into the interior thereof, and air may cool the body inside the cooling hole.

On the other hand, the air cooled by the transition piece flows into the annular space of the liner, and air is supplied to the outer wall of the liner from the outside of the flow sleeve through the cooling holes provided in the flow sleeve, have.

A deswooler is installed between the compressor 200 and the combustor 300 to adjust the flow angle of the air flowing into the combustor 300 to a designed flow angle. .

Next, the turbine 400 may be formed similarly to the compressor 200. That is, the turbine 400 includes a turbine blade 420 rotated together with the rotor 500, and a turbine vane 420 fixed to the casing 100 to align the flow of the air flowing into the turbine blade 420. (440).

The plurality of turbine blades 420 are formed in a plurality of stages along the axial direction of the rotor 500 and the plurality of the turbine blades 420 are formed in a plurality of stages, And may be formed radially along the rotation direction of the rotor 500.

That is, the root portion 420a of the turbine blade 420 is coupled to the turbine blade coupling slot of the turbine rotor disk 540, and the root portion 420a connects the root portion 420a of the turbine blade 420 to the turbine blade coupling slot The rotor 500 may be formed in a fir-tree shape to prevent the rotor 500 from being detached from the rotor 500 in the radial direction of rotation.

At this time, the turbine blade coupling slot may be formed in the form of a fir to correspond to the root portion 420a of the turbine blade.

In the present embodiment, the turbine blade root portion 420a and the turbine blade coupling slot are formed in the form of a fir tree, but are not limited thereto and may be formed in a dove tail form or the like. Alternatively, the turbine blades may be fastened to the turbine rotor disk using fasteners such as keys or bolts other than the above-described fastening devices.

The turbine rotor disk 540 and the turbine blade 420 are typically coupled in a tangential type or an axial type. In the present embodiment, the turbine blade root 420a Is inserted into the turbine blade coupling slot along the axial direction of the rotor 500 as described above. Accordingly, the plurality of turbine blade engagement slots may be radially arranged along the circumferential direction of the turbine rotor disk 540 according to the present embodiment.

The plurality of turbine vanes 440 may be formed in a plurality of stages along the axial direction of the rotor 500. Here, the turbine vane 440 and the turbine blades 420 may be alternately arranged along the air flow direction.

In addition, the plurality of turbine vanes 440 may be radially formed at each stage along the rotational direction of the rotor 500.

Unlike the compressor 200, the turbine 400 is in contact with a high-temperature and high-pressure combustion gas, and thus requires a cooling means for preventing damage such as deterioration.

Accordingly, the gas turbine according to the present embodiment may further include a cooling flow path for adding compressed air to a portion of the compressor 200 to supply the compressed air to the turbine 400.

The cooling channel may extend outside the casing 100 (outer channel) or extend through the inner portion of the rotor 500 (inner channel), and both the outer channel and the inner channel may be extended It can also be used.

At this time, the cooling passage communicates with a turbine blade cooling passage formed in the turbine blade 420, so that the turbine blade 420 can be cooled by the cooling air.

The cooling air is supplied to the surface of the turbine blades 420 so that the turbine blades 420 are cooled by the cooling air flowing through the cooling holes of the turbine blades 420, So-called film cooling by the cooling air.

In addition, the turbine vane 440 may be formed to be cooled by receiving cooling air from the cooling passage similarly to the turbine blade 420.

In the gas turbine 1 according to this configuration, the air introduced into the casing 100 is compressed by the compressor 200, and the air compressed by the compressor is mixed with the fuel by the combustor 300 The combustion gas generated in the combustor flows into the turbine 400 and the combustion gas introduced into the turbine 400 is supplied to the rotor 500 through the turbine blade 420 And then discharged to the atmosphere through the diffuser. The rotor 500, which is rotated by the combustion gas, can drive the compressor 200 and the generator. That is, some of the mechanical energy obtained from the turbine may be supplied to the compressor as energy required to compress the air, and the remainder may be used to produce power to the generator.

Here, the gas turbine is only an embodiment of the present invention, and the control unit for controlling the angle of the IGV of the present invention and its control method, which will be described in detail below, can be applied to all gas turbines in general.

Hereinafter, the control unit 600 and a control method thereof will be described in detail.

In this embodiment, the control unit 600 includes a first angle control unit 620 for controlling the angle of the IGV 241 so as not to exceed the maximum exhaust gas temperature EGT until a target load is reached, And a second angle control unit 660 for controlling the angle of the IGV 241 according to the engine efficiency when the concentration determined by the concentration determination unit does not exceed the limit value, . ≪ / RTI >

The first angle control unit 620 maintains the angle of the IGV 241 at the minimum angle when the maximum exhaust gas temperature is not reached and flows into the compressor 200 when the maximum exhaust gas temperature is reached The angle of the IGV 241 may be adjusted to increase the amount of air to be supplied.

That is, when the temperature of the exhaust gas does not exceed the maximum limit value, the angle of the IGV 241 is maintained at a minimum angle (closed state) as shown in FIG. 3 so that the amount of air flowing into the compressor 200 becomes minimum .

At this time, the minimum angle of the IGV 241 may correspond to -50 ° as described above, and the maximum exhaust gas temperature EGT may be set to 640 ° C. However, it should be understood that the present invention is not limited thereto and can be set at different angles and temperatures.

Further, when the temperature of the exhaust gas reaches the maximum limit value, the angle of the IGV 241 is adjusted so that the amount of air flowing into the compressor 200 can be increased. That is, by adjusting the angle of the IGV 241 to be close to the open state arranged in parallel to the flow direction of the air flowing into the compressor 200, the amount of air flowing into the compressor 200 is increased to increase the exhaust gas temperature EGT ) Can be lowered.

At this time, the amount of fuel supplied to the combustor 300 to reach the target load can be adjusted by the fuel controller 320, which will be described in detail in the following control method.

The concentration determiner 640 is for determining the concentration of NOx and CO after the angle of the IGV 241 is controlled by the first angle controller 620 and reaches the target load.

The concentration determiner 640 measures the concentrations of NOx and CO in the exhaust gas, compares the concentrations of the NOx and the CO, and determines whether or not the concentration exceeds or exceeds the limit value.

At this time, in this embodiment, the limit values of the NOx and CO can be set to 15 ppm and 10 ppm, respectively.

The second angle control unit 660 controls the angle of the IGV 241 according to the engine efficiency when the concentration of NOx and CO determined by the concentration determination unit 640 does not exceed the limit value.

The second angle control unit 660 includes an angle changing unit 662 for changing the angle of the IGV 241 by a predetermined angle and an efficiency evaluating unit for evaluating the engine efficiency each time the angle changing unit 662 changes the angle 664).

That is, the angle changing unit 662 changes the angle of the IGV 241 by a certain angle, in this embodiment, by 1 °, and the efficiency evaluating unit 664 changes the angle of the IGV 241 by the angle changing unit 662, So as to find the angle of the IGV 241 for maximum efficiency at the target load.

At this time, the angle changing unit 662 changes the angle of the IGV 241 by 1 degree, changes the value by 1 degree in different directions, compares the evaluated efficiency, and further increases the efficiency by 1 degree Can be changed.

That is, after the angle of the IGV 241 is changed by + 1 ° from the current angle, the efficiency evaluated by the efficiency evaluating unit 664 after changing by the efficiency evaluated by the efficiency evaluating unit 664 by -1 degrees To find the angle of the IGV at which the maximum efficiency appears by further changing the angle by 1 DEG in a direction in which the efficiency becomes higher.

The second angle control unit 660 determines whether or not the efficiency evaluated by the efficiency evaluation unit 664 after the angle of the IGV 241 is changed by the angle changing unit 662 is higher than the pre- The angle of the IGV 241 is further changed by the angle changing unit 662 so that the angle of the IGV 241 is restored to the angle before the change, The angle of the IGV 241 can be controlled to obtain efficiency.

In addition, the fuel regulator 320 may adjust the supply amount of the fuel to maintain the target load when the load changes due to the change of the angle of the IGV 241 by the second angle control unit 660.

Hereinafter, an operation process of controlling the angle of the gas turbine 1, specifically, the IGV 241 through the controller 600 will be described in detail.

First, when the target load is instructed to the gas turbine 1 (load command step), the amount of fuel supplied to the combustor 300 and the angle of the IGV 241 are controlled to reach the target load ( Target load reaching stage).

That is, the amount of fuel supplied to the combustor 300 is increased to reach the target load by the fuel controller 320, and the angle of the IGV 241 is controlled by the first angle controller 620 Respectively.

As the amount of fuel supplied to the combustor 300 is increased, the load increases and the exhaust gas temperature EGT also increases.

At this time, the angle of the IGV 241 may be controlled according to the exhaust gas temperature so as not to exceed the maximum exhaust gas temperature EGT until the target load is reached (first angle control step).

Specifically, when the temperature of the exhaust gas does not reach the maximum limit, the angle of the IGV 241 is maintained at a minimum angle so that the amount of air flowing into the compressor 200 can be minimized, and the temperature of the exhaust gas Controls the angle of the IGV (241) to increase the amount of air flowing into the compressor (200). That is, when the maximum exhaust gas temperature is reached, the angle of the IGV 241 is adjusted to be close to the open state arranged in parallel with the flow direction of the air flowing into the compressor 200, So that the exhaust gas temperature EGT can be lowered.

At this time, the minimum angle of the IGV 241 may correspond to -50 ° as described above, and the maximum exhaust gas temperature EGT may be set to 640 ° C.

Accordingly, if the exhaust gas temperature reaches the maximum limit value, that is, 640 DEG C in this embodiment, the load operation can be maintained in that state, and if the exhaust gas temperature reaches 640 DEG C before reaching the target load The maximum exhaust gas temperature EGT can be limited by adjusting and controlling the angle of the IGV 241 to reach the target load.

At this time, it may vary depending on the design of the gas turbine, but in general, the target load at which the maximum EGT appears may be 30-40%.

After reaching the target as described above, the concentration of NOx and CO is determined (concentration determination step).

That is, the concentration determiner 640 measures the concentrations of NOx and CO in the exhaust gas, and compares them with the respective limit values to determine whether or not the limit value is exceeded or not.

At this time, in this embodiment, the limit values of the NOx and CO can be set to 15 ppm and 10 ppm, respectively.

Accordingly, if the concentration of NOx and CO determined by the concentration determination unit 640 exceeds the limit value, the load operation is maintained in that state. If the concentration does not exceed the limit value, the angle of the IGV 241 Additional control should be done to obtain maximum efficiency.

Next, when the concentration determined by the concentration determination step does not exceed the limit value, the angle of the IGV 241 may be controlled according to the engine efficiency (second angle control step).

That is, the angle of the IGV 241 can be controlled by the second angle control unit 660, and more specifically, the angle of the IGV 241 is changed by the angle changing unit 662 by a predetermined angle And the efficiency evaluation unit 664 can evaluate the engine efficiency at every change.

As described above, the second angle control step allows the angle changing unit 662 to change the angle of the IGV 241 by a predetermined angle, in this embodiment, by 1 degree, and the efficiency evaluating unit 664 may be controlled by the angle of the IGV 241 for maximum efficiency at the target load by allowing the engine efficiency to be evaluated each time the angle is changed.

At this time, the angle changing unit 662 changes the angle of the IGV 241 by 1 degree, changes the value by 1 degree in different directions, compares the evaluated efficiency, and further increases the efficiency by 1 degree Can be changed.

If the efficiency evaluated by the efficiency evaluation unit 664 is higher than the efficiency before the change after the angle of the IGV 241 is changed by the angle changing unit 662, The angle of the IGV 241 may be further changed by the changing unit 662 and the concentration may be determined first by the concentration determining step.

On the contrary, if the IGV 241 is lower than the pre-change efficiency, the angle of the IGV 241 can be restored to the pre-change angle, thereby controlling the angle of the IGV 241 for obtaining the maximum efficiency at the target load.

Further, when the angle of the IGV 241 is changed by the second angle control step, the supply amount of the fuel can be adjusted so as to maintain the target load when the load fluctuates (fuel supply adjustment step). This can be controlled by the fuel regulator 320.

According to the present invention, not only the maximum EGT is limited and the angle of the IGV is adjusted to the target load, but the maximum efficiency in the target load can be obtained by further adjusting the angle of the IGV according to the engine efficiency even after reaching the target load It is effective.

In addition, it is possible to satisfy the emission by judging the concentrations of NOx and CO.

The present invention is not limited to the above-described specific embodiment and description, and various changes and modifications may be made by those skilled in the art without departing from the scope of the present invention as claimed in the claims. And such modifications are within the scope of protection of the present invention.

1: gas turbine 100: casing
102: compressor casing 103: combustor casing
104: turbine casing 200: compressor
220: compressor blade 220a: compressor blade root portion
221, 222, 223: a first- to third-stage compressor blade
240: compressor vane 241: IGV (Inlet Guide Vane)
242, 243, 244: two-stage to four-stage variable vanes
261, 262, 263, 264: spindles 281, 282, 283, 284:
300: combustor 320: fuel regulator
400: Turbine 420: Turbine blade
420a: turbine blade root portion 440: turbine vane
500: rotor 520: compressor rotor disk
530: torque tube 540: turbine rotor disk
550: Tie rod 560: Fixing nut
600: control unit 620: first angle control unit
640: density determination unit 660: second angle control unit
662: angle changing section 664: efficiency evaluation section

Claims (20)

Casing;
A compressor disposed in the casing for sucking air and compressing the compressed air to a high pressure;
A combustor for combusting the air compressed by the compressor with the fuel;
A turbine for rotating the plurality of turbine blades using the high-temperature, high-pressure combustion gas discharged from the combustor to produce electric power;
An IGV (Inlet Guide Vane) provided at an inlet of the compressor and connected to the casing in an angle-adjustable manner; And
And a controller for controlling the angle of the IGV,
Wherein,
A first angle control unit for controlling the angle of the IGV so as not to exceed the maximum exhaust gas temperature (EGT) until the target load is reached;
A concentration determination unit for determining a concentration of nitrogen oxide (NOx) and carbon monoxide (CO) after reaching a target load; And
A second angle control unit for controlling the angle of the IGV according to the engine efficiency when the concentration determined by the concentration determination unit does not exceed the limit value;
. The method according to claim 1,
Wherein the first angle control unit comprises:
Wherein the angle of the IGV is controlled to maintain the angle of the IGV at a minimum angle when the maximum exhaust gas temperature is not reached and to increase the amount of air flowing into the compressor when the maximum exhaust gas temperature is reached, Gas turbine. 3. The method of claim 2,
Wherein the minimum angle of the IGV is -50 °. The method according to claim 1,
Wherein the limit values of NOx and CO are 15 ppm and 10 ppm, respectively. The method according to claim 1,
Wherein the second angle control unit comprises:
An angle changing unit for changing the angle of the IGV by a predetermined angle; And
An efficiency evaluating unit for evaluating the engine efficiency at every change by the angle changing unit;
. 6. The method of claim 5,
Wherein the angle changing unit changes the angle of the IGV by 1 DEG. The method according to claim 6,
Wherein the angle changing unit changes the angles of the IGV by 1 DEG in different directions, compares the evaluated efficiencies, and further changes the angle by 1 DEG in a direction of increasing the efficiency. 6. The method of claim 5,
Wherein the second angle control unit comprises:
The angle changing unit may further change the angle of the IGV when the efficiency evaluated by the efficiency evaluating unit is higher than the conversion efficiency after the angle of the IGV is changed by the angle changing unit, So that the angle of the IGV is restored to an angle before the change. The method according to claim 1,
Wherein the maximum exhaust gas temperature (EGT) is 640 占 폚. The method according to claim 1,
And a fuel regulator for regulating a supply amount of fuel supplied to the combustor,
Wherein the fuel regulator adjusts the supply amount of the fuel so as to reach and maintain the target load when the angle of the IGV is controlled by the first angle control part and the second angle control part. A combustor for combusting the air compressed by the compressor with the fuel to burn the high temperature and high pressure combustion gas discharged from the combustor; A method of controlling a gas turbine including a turbine that rotates a plurality of turbine blades and generates electric power using an electric motor, and an IGV (Inlet Guide Vane) that is provided at an inlet of the compressor and is angularly adjustable to the casing ,
A load command step for commanding a target load;
A target load reaching step of controlling an amount of fuel supplied to the combustor to reach the target load and an angle of the IGV;
Determining a concentration of nitrogen oxide (NOx) and carbon monoxide (CO) after reaching a target load; And
A second angle control step of controlling the angle of the IGV according to the engine efficiency when the concentration determined by the concentration determination step does not exceed the limit value;
/ RTI > 12. The method of claim 11,
The target load reaching step includes:
And a first angle control step of controlling the angle of the IGV so as not to exceed the maximum exhaust gas temperature (EGT) until the target load is reached. 13. The method of claim 12,
Wherein the first angle control step comprises:
Controlling the angle of the IGV so as to increase the amount of air flowing into the compressor when the maximum exhaust gas temperature is not reached, while maintaining the angle of the IGV at the minimum angle when the maximum exhaust gas temperature is not reached Wherein the gas turbine is a gas turbine. 14. The method of claim 13,
Wherein the minimum angle of the IGV is -50 °. 12. The method of claim 11,
Wherein the limit values of NOx and CO are 15 ppm and 10 ppm, respectively. 12. The method of claim 11,
Wherein the second angle control step comprises:
Wherein the angle of the IGV is changed by a predetermined angle and the engine efficiency is evaluated at each change to control the angle of the IGV with the highest efficiency. 17. The method of claim 16,
Wherein the second angle control step changes the angle of the IGV by 1 DEG. 18. The method of claim 17,
Wherein the second angle control step changes the angle of the IGV by 1 DEG in different directions, compares the evaluated efficiencies, and further changes the angle by 1 DEG in a direction of increasing the efficiency. . 13. The method of claim 12,
Wherein the maximum exhaust gas temperature (EGT) is 640 ° C. 12. The method of claim 11,
A fuel supply regulating step for regulating a supply amount of the fuel so as to maintain the target load when the load is changed as the angle of the IGV is changed by the second angle control step;
Further comprising the steps of:

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