KR101957590B1 - Method for controlling tip clearance, apparatus for controlling tip clearance and gas turbine comprising the same - Google Patents

Abstract

The present invention relates to a method for controlling a tip clearance, an apparatus for controlling a tip clearance, and a gas turbine comprising the same. According to the present invention, the method for controlling the tip clearance comprises: (A) a step of measuring a tip clearance for each stage of a blade; (B) a step of selecting a minimum value and a maximum value from among the tip clearances measured for each stage; (C) a step of determining if the minimum value and the maximum value belong to a pre-set reference range; and (D) a step of, when the minimum value and the maximum value do not belong to the reference range, moving the blade. According to the present invention, the method for controlling the tip clearance, the apparatus for controlling the tip clearance, and the gas turbine comprising the same are able to allow the blade to move forward or backward in accordance with whether the measured tip clearance belongs to a pre-set reference range or not, and to automatically, precisely control the tip clearance.

Description

TECHNICAL FIELD The present invention relates to a tip clearance control method, a tip clearance control method, and a gas turbine including the tip clearance control method.

The present invention relates to a tip clearance control method, a tip clearance control apparatus, and a gas turbine including the tip clearance control method. More particularly, the present invention relates to a method of controlling a tip clearance formed between a blade of a turbine for a gas turbine and a casing, And a gas turbine including the same.

Gas turbines consist of compressors, combustors and turbines. The compressor is provided with a compressor inlet scroll strut introducing air, and a plurality of compressor vanes and compressor blades are alternately arranged in the compressor casing. The combustor supplies fuel to the compressed air compressed in the compressor and ignites it with an igniter, so that combustion gas of high temperature and high pressure is generated.

The turbine has a plurality of turbine vanes and turbine blades disposed alternately in the turbine casing. Further, a tie rod is disposed in the gas turbine so as to pass through the center of the compressor, the combustor, the turbine and the exhaust chamber. Both ends of the tie rod are rotatably supported by bearings. A plurality of disks are fixed to the tie rods so that respective blades are connected and a drive shaft such as a generator is connected to an end of the exhaust chamber side.

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.

Briefly describing the operation of the gas turbine, the compressed air in the compressor is mixed with the fuel and burned to produce a high-temperature combustion gas, and the combustion gas thus produced is injected toward the turbine. The injected combustion gas passes through the turbine vane and the turbine blades to generate a rotational force, which causes the rotor to rotate.

At this time, a gap defined by a tip clearance is formed between the turbine casing and the blade. When the tip clearance is increased above the proper level, the amount of flue gas escaping between the turbine casing and the blades increases without work and the efficiency of the entire gas turbine is reduced. On the contrary, if the tip clearance becomes smaller than a proper level, the blade will scratch the inner wall of the turbine casing. Therefore, adjusting the tip clearance of the turbine at an appropriate level is closely related to improving the performance of the gas turbine.

As a technology related to the tip clearance of such a gas turbine, Korean Utility Model Registration No. 20-0174662 discloses a gas turbine.

Generally, a method of moving the turbine blades is mainly used to adjust the tip clearance to an appropriate level. However, the conventional gas turbine has a limitation in manually moving the turbine blade relative to the fixed turbine casing in order to adjust the tip clearance of the turbine. When the turbine blades are moved manually, the tip clearance can not be precisely controlled, thereby deteriorating the overall efficiency of the gas turbine.

It is an object of the present invention to provide an improved tip clearance control method, a tip clearance control device, and a gas turbine including the tip clearance control device, which can automatically measure and precisely control a tip clearance. .

A method for controlling a tip clearance between a blade of a turbine for a gas turbine and a casing, the method comprising the steps of: (A) measuring a tip clearance for each stage of the blade ; (B) selecting a minimum value and a maximum value among the tip clearances measured for each stage; (C) determining whether the minimum value and the maximum value fall within a preset reference range; And (D) moving the blade if the minimum and maximum values do not fall within the reference range.

According to another aspect of the present invention, there is provided an apparatus for controlling a tip clearance formed between a blade of a turbine for a gas turbine and a casing, the apparatus comprising: a sensor for measuring a tip clearance for each stage of the blade, part; A hydraulic motor installed at one side of the turbine and moving the blade; And a control unit for selecting the minimum and maximum values of the tip clearances for each stage of the blade transmitted from the measuring unit and operating the hydraulic motor when the selected minimum value and maximum value do not fall within a preset reference range A clearance control device is provided.

According to another aspect of the present invention, A compressor installed at one side of the tie rod for sucking and compressing air; A combustor which mixes compressed air supplied from the compressor with fuel and burns the compressed air; A stator including a casing provided on the other side of the tie rod and a vane provided on an inner circumferential surface of the casing; a disk provided inside the casing; and a stator provided on the outer peripheral surface of the disk, A turbine including a blade, the turbine including a rotor rotating by a combustion gas supplied from the combustor; And a tip clearance control device for controlling a tip clearance formed between the blade and the casing, wherein the tip clearance control device comprises a measurement unit installed in the turbine and measuring a tip clearance for each stage of the blade, A hydraulic motor that is installed on one side of the turbine and moves the blade, and a controller that selects a minimum value and a maximum value among the tip clearances for each stage of the blade transmitted from the measuring unit, And a control section for operating the hydraulic motor when the hydraulic motor does not fall within the reference range.

The tip clearance may be defined as a distance in a linear direction connecting the inner surface of the casing and the end surface of the blade vertically, respectively.

Wherein an angle formed between a straight line in an axial direction of a tie rod for a gas turbine passing through the center of the turbine and an end surface of the blade is defined as ata and an interval between the inner surface of the casing and the end surface of the blade , And when the interval in the radial direction of the tie rod is defined as a hypotenuse, the measuring unit measures the setta value and the hypotenuse value, and transmits the calculated theta value and the hypotenuse value to the control unit, The tip clearance can be calculated.

The tip clearance may be defined as a minimum value of a radial distance of a tie rod for a gas turbine passing through the center of the turbine when the same stage is taken as a reference.

When the measured tip clearance minimum value is smaller than the lower limit of the reference range, the controller may operate the hydraulic motor to move the blade back to the rear-stage side of the turbine.

When the measured maximum value of the tip clearance is larger than the upper limit value of the reference range, the controller may operate the hydraulic motor to advance the blade toward the front-stage side of the turbine.

Wherein when the measured tip clearance minimum value is smaller than the lower limit value of the reference range and the measured maximum value of the tip clearance is larger than the upper limit value of the reference range, a difference between the minimum value and the lower limit value, And the upper limit value can be calculated.

The control unit may operate the hydraulic motor to move the blade so that the difference between the minimum value and the lower limit value and the difference between the maximum value and the upper limit value become equal to each other.

According to the tip clearance control method, the tip clearance control apparatus, and the gas turbine including the tip clearance control method, the tip clearance can be automatically or automatically adjusted by allowing the blade to move forward or backward according to whether the measured tip clearance falls within a predetermined reference range Precise control is possible.

1 is a cross-sectional view showing a schematic structure of a gas turbine to which an embodiment of the present invention is applied.
FIG. 2 is an enlarged cross-sectional view of the turbine casing in such a manner that the inner surface of the turbine casing and the end surface of the turbine blade are formed to be parallel to each other.
Fig. 3 is a reference view for explaining the tip clearance, theta and hypotenuse in Fig. 2;
FIG. 4 is an enlarged cross-sectional view of the turbine casing in such a manner that the inner surface of the turbine casing and the end surface of the turbine blade are formed so as not to be parallel to each other.
5 is a flowchart of a tip clearance control method according to an embodiment of the present invention.
6 is a flowchart showing an algorithm for implementing the tip clearance control method according to FIG.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the true scope of the present invention should be determined by the technical idea of the appended claims.

Hereinafter, an embodiment of a tip clearance control method, a tip clearance control apparatus, and a gas turbine including the tip clearance control method according to the present invention will be described with reference to the drawings.

Referring to Figure 1, an example of a gas turbine 10 according to the present invention is shown. The gas turbine 10 has a casing, and a turbine diffuser is disposed at a rear side of the casing to discharge a combustion gas passing through the turbine 100. And a combustor 13 for supplying compressed air to the front of the turbine diffuser and burning the air.

Referring to the flow direction of the air, the compressor 12 is located on the upstream side of the housing, and the turbine 100 is disposed on the downstream side of the housing. At this time, the housing includes a compressor casing and a turbine casing 111. The compressor casing houses a compressor vane and a compressor rotor therein, and the turbine casing 111 houses a turbine vane 112 and a turbine rotor 120 therein. A torque tube is disposed between the compressor (12) and the turbine (100) as a torque transmitting member for transmitting rotational torque generated from the turbine (100) to the compressor.

The compressor rotor includes a compressor disk, a compressor blade. A plurality of (for example, 14) compressor discs are provided in the compressor casing, and each of the compressor discs is fastened so as not to be axially spaced by the tie rods.

Specifically, each of the compressor discs is arranged substantially in the center along the axial direction with the tie rods penetrating. Here, each of the neighboring compressor discs is disposed such that opposed surfaces thereof are pressed by the tie rods, and relative rotation is not possible.

A plurality of compressor blades are radially coupled to the outer circumferential surface of the compressor disk. A plurality of compressor vanes fixedly disposed in the compressor casing are positioned between the respective compressor disks. The compressor vane is fixed so as not to rotate unlike the compressor disk, and aligns the flow of the compressed air passing through the compressor blades, thereby guiding the compressed air to the compressor blades located on the downstream side. At this time, the compressor casing and the compressor vane corresponding to the fixed body may be defined as a comprehensive name of a compressor stator in order to distinguish the compressor rotor corresponding to the rotating body.

The tie rod is arranged to pass through the center of the plurality of compressor discs and turbine discs. One end of the tie rod is fastened in the compressor disk located on the most upstream side and the other end is fastened by a fixing nut.

The shape of the tie rods may be variously structured depending on the gas turbine, and therefore is not necessarily limited to the shape shown in Fig. That is, as shown in the figure, one tie rod may pass through the center portion of the compressor disk and the turbine disk, or may have a configuration in which a plurality of tie rods are arranged circumferentially, or may be used in combination.

Although not shown, a compressor of a gas turbine may be equipped with a despooler which acts as a guide pin to increase the flow angle of the fluid entering the combustor inlet after increasing the pressure of the fluid to the design flow angle.

The combustor mixes and combusts the compressed air with the fuel to produce a high-temperature high-temperature and high-pressure combustion gas, and the temperature of the combustion gas is increased to the heat resistance limit at which the combustor and turbine components can withstand.

A plurality of combustors constituting a combustion system of a gas turbine may be arranged in a combustor casing formed in a cell shape and include a nozzle for injecting fuel, a liner for forming a combustion chamber, and a transition part for connecting the combustor and the turbine. And a transition piece.

Specifically, the liner provides a combustion space in which the fuel injected by the nozzle is mixed with the compressed air of the compressor and burned. Such a liner may include a flame passage providing a combustion space in which fuel mixed with air is combusted, and a flow sleeve forming an annular space surrounding the flame tube. A fuel nozzle is coupled to the front end of the liner, and a spark plug is coupled to the side wall.

On the other hand, a transition piece is connected to the rear end of the liner so that the combustion gas burned by the spark plug can be sent to the turbine side. This transition piece is cooled by compressed air supplied from the compressor through the outer wall portion so as to prevent breakage by the high temperature of the combustion gas.

To this end, the transition piece is provided with holes for cooling so as to inject air into the inside thereof, and the compressed air flows to the liner side after cooling the body inside the holes through the holes.

The compressed air that has cooled the transition piece flows through the annular space of the liner. Compressed air may be supplied to the outer wall of the liner from the outside of the flow sleeve through the cooling holes provided in the flow sleeve to collide with the compressed air.

On the other hand, the high-temperature and high-pressure combustion gases from the combustor are supplied to the turbines described above. The supplied high-temperature and high-pressure combustion gas expands and gives a reaction force to the turbine blades to induce a rotational torque, and the rotational torque thus obtained is transmitted to the compressor through the torque tube described above. The power exceeding the power required for driving the compressor Generator and so on.

The turbine 100 is basically similar in structure to the compressor 12. That is, the turbine 100 is also provided with a plurality of turbine rotors 120 similar to the compressor rotor of the compressor 12. Thus, the turbine rotor 120 also includes a turbine disk 121 and a plurality of turbine blades 122 radially disposed therefrom. A plurality of turbine vanes 112 fixed to the turbine casing 111 are provided between the turbine blades 122 to guide the flow direction of the combustion gas passing through the turbine blades 122. The turbine casing 111 and the turbine vane 112 corresponding to the fixed body may also be defined as a generic name of the turbine stator 110 in order to distinguish the turbine casing from the turbine rotor 120 corresponding to the rotating body have.

The gas turbine 10 according to an embodiment of the present invention includes a tip clearance control device 1000 (hereinafter referred to as a control device) for controlling a tip clearance formed between the turbine blade 122 and the casing 111, As shown in FIG.

The control apparatus 1000 includes a measuring section 1100, a hydraulic motor 1200, and a control section 1300. [ The measurement unit 1100 is installed in the turbine 100 and measures all the tip clearances of the stages where the blades 122 are located. The measuring unit 1100 transmits information about the measured tip clearance to the controller 1300.

The hydraulic motor 1200 is installed on one side of the turbine 100 and moves the blade 122. More specifically, the hydraulic motor 1200 is configured to advance the turbine disk 121 to the front-stage side of the turbine 100, or to move the rear end of the turbine 100 ). Thus, the blade 122 moves forward or backward together with the disc 121. In this case, when the hydraulic motor 1200 advances or retreats the turbine disk 121, a torque tube or a compressor disk, a compressor blade, and a tie bolt integrally coupled to the turbine disk 121 are also separated from the turbine disk 121). ≪ / RTI >

The controller 1300 selects a minimum value and a maximum value among the tip clearances for each stage of the turbine 100 received from the measuring unit 1100 and determines whether the selected minimum value and the maximum value are within a preset reference range do. As a result, when the selected minimum value and the maximum value do not belong to the reference range, the hydraulic motor 1200 is operated to move the blade 122 forward or backward.

2 and 3, assuming that the inner surface of the casing 111 of the turbine 100 and the end surface of the blade 122 are parallel to each other, the tip clearance CL is formed in the casing 111 And the end surfaces of the blades 122, respectively. The measurement unit 1100 measures the value of the tip clearance CL defined in this manner for each stage, and transmits the measurement result to the control unit 1300. [

Theta is defined as an angle between a straight line X in the axial direction of the tie rod 11 and an end surface of the blade 122. The inner surface of the casing 111, When the interval between the end surfaces of the tie rod 11 in the radial direction R is defined as the hypotenuse h, the measurement unit 1100 calculates the tip clearance CL Theta (θ) value and the hypotenuse (h) may be measured and transmitted to the controller 1300. The control unit 1300 can calculate the tip clearance CL by applying the trigonometric function to the received theta value and the hypotenuse value. That is, in this case, the measurement unit 1100 does not directly measure the tip clearance CL but indirectly measures the value using theta (?) Value and the hypotenuse (h) value. Here, the trigonometric function method can be simply summarized by multiplying the hypotenuse (h) by the cosine of theta (?) Value.

4, the tip clearance CL is not a straight line direction perpendicular to the inner surface of the casing 111 and the end surface of the blade 122, but extends in the radial direction of the tie rod 11 R). ≪ / RTI > More specifically, the tip clearance CL is set such that the tip clearance CL is equal to or greater than the gap (not shown) that is aligned in the radial direction R of the tie rod 11 between the casing 111 and the blade 122, , And a minimum value among the three values. For example, in FIG. 4, the radial distance R from the rightmost tip of the blade 122 to the casing 111 will be the tip clearance CL.

4, a tip clearance is defined between the casing 111 and the blade 122 even when the inner surface of the casing 111 and the end surface of the blade 122 are not parallel to each other . In this case, one tip clearance is defined for each stage. The controller 1300 selects the minimum value and the maximum value among the tip clearances at each of the stages defined as described above.

The control unit 1300 operates the hydraulic motor 1200 to rotate the blade 122 in a direction in which the tip clearance CL is smaller than the lower limit LL of the reference range, (B) to the rear end side of the turbine 100. In this case, since the distance between the casing 111 and the blade 122 increases, it is possible to prevent the blade 122 from eating the inner wall of the casing 111.

On the other hand, when the measured maximum value of the tip clearance CL is greater than the upper limit (UL) of the reference range, the control unit 1300 operates the hydraulic motor 1200 to rotate the blade 122) to the front end side of the turbine (100). In this case, the amount of the combustion gas leaking out between the casing 111 and the blade 122 can be reduced. Therefore, the amount of the rotational torque received by the turbine blades 122 by the combustion gas can be increased, and the efficiency of the entire gas turbine 10 can be improved.

At this time, the reference range may be set to be the same for each stage or may be set differently for each stage. The reference range may be variously set by various factors such as the structure of the designed gas turbine 10, the operating environment of the gas turbine 10, the driving capacity, and the like. In addition, the reference range may be designed differently for each drive timing of the same gas turbine 10. [

For example, during start-up operation of the gas turbine 10, not only is the amount of heat received by the turbine blades 122 more than that of the turbine casing 111 by the combustion gas, The centrifugal force is radially outwardly applied to the blade 122, so that the expansion rate of the blade 122 is larger than the expansion rate of the casing 111. Therefore, when the starting operation of the gas turbine 10 is started, the reference range is adjusted downward, and when the end of the blade 122 is at least close to the inner surface of the casing 111, So that the blade 122 can be moved backward. Conversely, during the steady-stage operation of the gas turbine 10, since the turbine casing 111 receives a sufficient amount of heat from the combustion gas, the turbine casing 111 and the end of the blade 122 There will be a certain distance in the space. Therefore, during the normal operation of the gas turbine 10 as described above, the reference range may be adjusted upward to allow the control unit 1300 to move the blade 122 forward.

Of course, the reference range can also be set separately for the off-design operation of the gas turbine 10. The de-design state means an operating condition in a state outside the design standard. The tip clearance CL may be rapidly reduced or increased depending on various factors in such a de-design state. Accordingly, in order to reduce the difference between the upper limit value UL and the lower limit value LL of the reference range, .

The control unit 1300 determines whether the tip clearance CL is smaller than the lower limit LL of the reference range and the maximum value of the tip clearance CL is greater than the upper limit UL of the reference range. The absolute value of the difference between the minimum value and the lower limit value LL and the difference between the maximum value and the upper limit value UL can be calculated. The control unit 1300 operates the hydraulic motor 1200 so that the difference between the minimum value and the lower limit value LL and the difference between the maximum value and the upper limit value UL become equal to each other, Forward or backward.

If the minimum value of the tip clearance CL is smaller than the lower limit value LL or only the maximum value of the tip clearance CL is larger than the upper limit value UL, It is clear. However, when the minimum value of the tip clearance CL is smaller than the lower limit value LL and the maximum value of the tip clearance CL is larger than the upper limit UL, it is clear that the tip clearance CL should be adjusted However, it is not clear whether the blade 122 should be advanced or reversed.

Accordingly, when the difference between the minimum value and the lower limit value LL and the absolute value of the difference between the maximum value and the upper limit value UL are calculated, the blade 122 moves in a direction in which the differences become equal to each other . That is, when the absolute value of the difference between the minimum value and the lower limit value LL is larger than the absolute value of the difference between the maximum value and the upper limit value UL, the blade clearance CL is maintained When the absolute value of the difference between the minimum value and the minimum value LL is smaller than the absolute value of the difference between the maximum value and the maximum value UL, the blade 122 is advanced to reduce the tip clearance CL can do.

In this case, the tip clearance CL can be maintained at a certain level for each stage of the turbine 100, and it is possible to prevent the tip clearance CL from excessively large or excessively small at any one stage have. Accordingly, according to the gas turbine 10 according to the embodiment of the present invention, the overall efficiency of the gas turbine 10 can be increased.

Hereinafter, the tip clearance control method (hereinafter referred to as a control method) of the present invention implemented by the control apparatus 1000 will be summarized with reference to FIGS. 5 and 6. FIG.

First, a reference range for comparing with the measured tip clearance is set in the control unit. At this time, the upper limit value and the lower limit value of the reference range can be variously set in consideration of the conditions such as start-up operation, steady-state operation, and off-design operation of the gas turbine as described above. Or may be set differently for each stage.

Then, the tip clearance for each stage is measured through the measuring unit. At this time, it is possible to directly measure the tip clearance defined as described above, or indirectly measure using the hypotenuse and theta. Then, the controller selects the minimum value and the maximum value among the tip clearances measured for each stage, and compares the minimum value and the maximum value with a preset reference range.

The control unit first determines whether the minimum value of the tip clearance is smaller than the lower limit value of the reference range that is already set and the maximum value of the tip clearance is smaller than or equal to the upper limit value of the preset reference range. If the minimum value of the tip clearance is smaller than the lower limit value of the preset reference range and the maximum value of the tip clearance is smaller than or equal to the upper limit value of the reference range already set, the control unit controls the hydraulic motor to reverse the turbine rotor.

However, if the minimum value of the tip clearance is not smaller than the lower limit value of the reference range already set, or if the maximum value of the tip clearance is not smaller than or equal to the upper limit value of the already set reference range, And it is determined whether or not the maximum value of the tip clearance is larger than the upper limit value of the reference range already set.

If the minimum value of the tip clearance is smaller than the lower limit value of the reference range already set and the maximum value of the tip clearance is larger than the upper limit value of the reference range that has already been set, the control unit compares the difference between the minimum value of the tip clearance and the lower limit value The absolute value and the absolute value of the difference between the maximum value of the tip clearance and the upper limit value of the already set reference range are compared. And the rotor is advanced or retracted such that the above differences become equal to each other.

At this time, if the absolute value of the difference between the minimum value of the tip clearance and the lower limit value of the already set reference range is larger than the absolute value of the difference between the maximum value of the tip clearance and the upper limit value of the already set reference range, the control unit controls to retract the blade . On the contrary, when the absolute value of the difference between the minimum value of the tip clearance and the lower limit value of the already set reference range is smaller than the absolute value of the difference between the maximum value of the tip clearance and the upper limit value of the already set reference range, the control unit controls to advance the blade .

However, if the minimum value of the tip clearance is not less than the lower limit value of the reference range already set, or the maximum value of the tip clearance is not larger than the upper limit value of the reference range already set, the control unit determines that the minimum tip clearance value is larger than the lower limit value And it is determined whether the maximum value of the tip clearance is larger than the upper limit value of the reference range already set.

If the minimum value of the tip clearance is equal to or greater than the lower limit value of the reference range already set and the maximum value of the tip clearance is larger than the upper limit value of the reference range already set, the control unit controls the hydraulic motor to advance the blade. If the minimum value of the tip clearance is equal to or greater than the lower limit value of the reference range already set and the maximum value of the tip clearance is smaller than or equal to the upper limit value of the reference range already set, Return to the step of selecting the minimum and maximum values of the tip clearance.

Since the tip clearance continuously changes during operation of the gas turbine, the minimum and maximum values of the selected tip clearance may differ from the previously selected minimum and maximum values, and a tip clearance of a different stage than the previously selected stage may be selected have. Accordingly, the control unit repeats the above-described comparison process based on the minimum and maximum values of the newly selected tip clearance.

On the other hand, the reference range to be initially set in the control unit may be set to a proper numerical value with a lower numerical value and an upper numerical value close to infinity, while the upper numeric value is set to an appropriate numerical value, It can also be set to a small number.

The maximum value of the tip clearance can not be larger than the upper limit value of the reference range. Therefore, only the minimum value of the tip clearance and the maximum value of the reference range Only the lower limit value is compared to control the tip clearance of the turbine. That is, the control unit controls the turbine blades so as to advance unconditionally.

On the other hand, when the upper limit value is set to an appropriate value as in the latter case, and the lower limit value is set to a very small value close to 0, since the minimum value of the tip clearance can not be smaller than the lower limit value of the reference range, So that the tip clearance of the turbine is controlled. That is, the control unit controls the turbine blades to be unconditionally reversed.

As described above, according to the tip clearance control method, the tip clearance control apparatus 1000, and the gas turbine 10 including the tip clearance control apparatus according to the present invention, depending on whether the measured tip clearance falls within a predetermined reference range , And the blade 122 is moved forward or backward, so that the tip clearance can be automatically and precisely controlled.

10: gas turbine 100: turbine
1000: Tip clearance control device 1100:
1200: Hydraulic motor 1300:

Claims (24)

A method of controlling a tip clearance formed between a blade of a turbine for a gas turbine and a casing,
(A) measuring a tip clearance for each stage of the blade;
(B) selecting a minimum value and a maximum value among the tip clearances measured for each stage;
(C) determining whether the minimum value and the maximum value fall within a preset reference range; And
(D) moving the blade if the minimum and maximum values do not fall within the reference range,
If the minimum value of the tip clearance selected in the step B is smaller than the lower limit value of the reference range and the maximum value of the tip clearance is larger than the upper limit value of the reference range,
The step C further includes measuring a difference between the minimum value and the lower limit value and a difference between the maximum value and the upper limit value,
Wherein the step (D) moves the blade so that the difference between the minimum value and the lower limit value and the difference between the maximum value and the upper limit value become equal to each other. The method according to claim 1,
Wherein the tip clearance is defined as an interval in a linear direction connecting vertically the inner surface of the casing and the end surface of the blade. The method of claim 2,
Wherein an angle formed between a straight line in an axial direction of a tie rod for a gas turbine passing through the center of the turbine and an end surface of the blade is defined as ata and an interval between the inner surface of the casing and the end surface of the blade When the radial distance of the rod is defined as the hypotenuse,
Wherein the step A calculates the tip clearance by applying a trigonometrical method to the measured theta value and the hypotenuse value. The method according to claim 1,
Wherein the tip clearance is defined as a minimum value of a radial distance of a tie rod for a gas turbine passing through the center of the turbine when the same stage is taken as a reference. delete delete The method according to claim 1,
The step (D)
When the absolute value of the difference between the minimum value and the lower limit value is larger than the absolute value of the difference between the maximum value and the upper limit value, the blade is moved toward the rear-stage side of the turbine with respect to the axial direction of the tie rod for gas turbine The blade is moved backward,
When the absolute value of the difference between the minimum value and the minimum value is smaller than the absolute value of the difference between the maximum value and the maximum value, the blade is moved toward the front-stage side of the turbine with respect to the axial direction of the tie rod for gas turbine And the tip clearance is advanced by advancing the blade. delete An apparatus for controlling a tip clearance formed between a blade of a turbine for a gas turbine and a casing,
A measurement unit installed on the turbine and measuring a tip clearance for each stage of the blade;
A hydraulic motor installed at one side of the turbine and moving the blade; And
And a controller for selecting a minimum value and a maximum value among tip clearances for each stage of the blade received from the measuring unit and operating the hydraulic motor when the selected minimum value and maximum value do not fall within a preset reference range,
Wherein,
Calculating a difference between the minimum value and the lower limit value and a difference between the maximum value and the upper limit value when the minimum value of the selected tip clearance is smaller than the lower limit value of the reference range and the maximum value of the tip clearance is larger than the upper limit value of the reference range,
And operates the hydraulic motor to move the blade so that the difference between the minimum value and the lower limit value and the difference between the maximum value and the upper limit value become equal to each other. The method of claim 9,
Wherein the tip clearance is defined as a distance in a linear direction connecting vertically the inner surface of the casing and the end surface of the blade. The method of claim 10,
Wherein an angle formed between a straight line in an axial direction of a tie rod for a gas turbine passing through the center of the turbine and an end surface of the blade is defined as ata and an interval between the inner surface of the casing and the end surface of the blade When the radial distance of the rod is defined as the hypotenuse,
Wherein the measuring unit measures the setta value and the hypotenuse value and transmits the measured value to the controller,
Wherein the controller calculates the tip clearance by applying a trigonometric function to the received theta value and the hypotenuse value. The method of claim 9,
Wherein the tip clearance is defined as a minimum value of a radial distance of a tie rod for a gas turbine passing through the center of the turbine when the same stage is taken as a reference. delete delete The method of claim 9,
Wherein,
When the absolute value of the difference between the minimum value and the lower limit value is larger than the absolute value of the difference between the maximum value and the upper limit value, the blade is moved toward the rear-stage side of the turbine with respect to the axial direction of the tie rod for gas turbine The blade is moved backward,
When the absolute value of the difference between the minimum value and the minimum value is smaller than the absolute value of the difference between the maximum value and the maximum value, the blade is moved toward the front-stage side of the turbine with respect to the axial direction of the tie rod for gas turbine And a tip clearance control device for advancing the blade. delete Tie rods; A compressor installed at one side of the tie rod to suck and compress air; A combustor which mixes compressed air supplied from the compressor with fuel and burns the compressed air; A stator including a casing provided on the other side of the tie rod and a vane provided on an inner circumferential surface of the casing; a disk provided inside the casing; and a blade installed on an outer circumferential surface of the disk, A turbine including a rotor rotating by a combustion gas supplied from the combustor; And a tip clearance control device for controlling a tip clearance formed between the blade and the casing,
The tip clearance control device includes:
A measurement unit installed on the turbine and measuring a tip clearance for each stage of the blade,
A hydraulic motor installed at one side of the turbine and moving the blade,
And a controller for selecting a minimum value and a maximum value among the tip clearances for each stage of the blade received from the measuring unit and operating the hydraulic motor when the selected minimum value and maximum value do not fall within a preset reference range,
Wherein,
Calculating a difference between the minimum value and the lower limit value and a difference between the maximum value and the upper limit value when the minimum value of the selected tip clearance is smaller than the lower limit value of the reference range and the maximum value of the tip clearance is larger than the upper limit value of the reference range,
And the hydraulic motor is operated to move the blade so that the difference between the minimum value and the lower limit value and the difference between the maximum value and the upper limit value become equal to each other. 18. The method of claim 17,
Wherein the tip clearance is defined as a distance in a linear direction connecting vertically the inner surface of the casing and the end surface of the blade, respectively. 19. The method of claim 18,
Wherein an angle formed between a straight line in the axial direction of the tie rod and an end surface of the blade is defined as ata and a gap in a radial direction of the tie rod between an inner surface of the casing and an end surface of the blade is defined as a hypotenuse When defined,
Wherein the measuring unit measures the setta value and the hypotenuse value and transmits the measured value to the controller,
Wherein the controller calculates the tip clearance by applying a trigonometric function to the received theta value and the hypotenuse value. 18. The method of claim 17,
Wherein the tip clearance is defined as indicating a minimum of a radial distance of a tie rod for a gas turbine passing through the center of the turbine based on the same end. delete delete 18. The method of claim 17,
Wherein,
Stage blade of the turbine with respect to the axial direction of the tie rod when the absolute value of the difference between the minimum value and the lower limit value is larger than the absolute value of the difference between the maximum value and the upper limit value, Lt; / RTI >
Stage side of the turbine with respect to the axial direction of the tie rod when the absolute value of the difference between the minimum value and the lower limit value is smaller than the absolute value of the difference between the maximum value and the upper limit value, Gas Turbines Advancing. delete

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