KR101884594B1 - Apparatus and Method for controlling Gas Turbine - Google Patents

Abstract

The present invention relates to an apparatus to control a gas turbine, capable of reducing hazardous gas discharged from the gas turbine, and a method thereof. According to the present invention, a gas turbine system comprises: a compressor to suck and compress air; a supplier to supply the compressed air compressed in the compressor to a combustor and a turbine; the combustor combusting the compressed air and fuel to generate high pressure and high temperature combustion gas; and the turbine rotated by the combustion gas generated from the combustor, and operating a generator by rotation of the turbine. An apparatus to control the gas turbine system comprises: a sensing unit to measure a turbine inlet temperature representing the temperature of a turbine inlet receiving the combustion gas generated from the combustor and a discharge gas temperature representing the temperature of discharge gas discharged from the turbine; and a control unit to control the supplier in order to control the amount of compressed air supplied to the turbine based on the turbine inlet temperature and the discharge gas temperature measured by the sensing unit. Accordingly, complete combustion is able to be performed in the combustor at a low load state, thereby providing an effect of reducing the amount of discharged hazardous gas.

Description

TECHNICAL FIELD [0001] The present invention relates to a gas turbine control apparatus,

The present invention relates to a gas turbine control apparatus and method, and more particularly, to a gas turbine control apparatus and method for reducing noxious gas discharged from a gas turbine.

BACKGROUND ART [0002] Generally, an engine or an apparatus having a turbine such as a gas turbine or a steam turbine is a power generating device that converts thermal energy of a gas or a fluid into rotational force, which is mechanical energy, And a stator for supporting and enclosing the rotor.

The structure of a gas turbine used in a power plant or the like for producing electricity is briefly described as follows. A compressor for compressing air to supply high-pressure air to a combustor, a combustor for generating combustion gas, and a turbine driven by a combustion gas discharged from the combustor . ≪ / RTI >

The compressor of the gas turbine is generally integrated with the shaft of the turbine and rotates in the same manner as the turbine, and is compressed by sucking the outside air while rotating the shaft. The compressed air is supplied to the combustor. In the combustor, the compressed air is supplied to the compressed air for combustion, thereby generating the high-temperature, high-pressure combustion gas and supplying it to the turbine.

The high-temperature, high-pressure combustion gas supplied to the turbine drives the rotor blades of the turbine to rotate the rotor of the turbine.

The gas turbine thus constructed is equipped with a system in which the compressed air in the compressor feeds some compressed air to the turbine and some to the combustor to cool the turbine.

In general, the gas turbine is controlled to maintain the temperature at the turbine inlet at the optimum temperature to maximize efficiency and minimize exhaust gas. However, as the load decreases, it becomes difficult to keep the temperature of the turbine inlet constant and eventually becomes low. As the temperature of the turbine inlet decreases, the harmful exhaust gas increases accordingly. Therefore, even when the load is low, a control is required to keep the temperature of the turbine inlet constant so as to prevent the increase of the harmful exhaust gas.

It is an object of the present invention to provide a gas turbine control apparatus and method for keeping the temperature of a turbine inlet constant at an optimal temperature even under a low load condition.

According to an aspect of the present invention, there is provided a compressor comprising: a compressor for sucking and compressing air according to the present invention; a feeder for supplying compressed air compressed by the compressor to a combustor and a turbine; And a turbine rotating by a combustion gas generated in the combustor, the turbine being driven by the rotation of the turbine, wherein the control device controls the rotation of the rotor provided in the turbine, A sensing unit for measuring the temperature of the exhaust gas discharged from the turbine and a speed of the exhaust gas discharged from the turbine, and a sensing unit for sensing the temperature of the exhaust gas discharged from the turbine, And an axial air control unit for controlling the feeder to adjust the amount of the compressed air, The exhaust gas temperature is the set threshold value, the rotation speed of the rotor is the inflection point rotation speed, and the inflection point rotation speed is a temperature at which the exhaust gas temperature is lower than the predetermined threshold value, The control unit controls the feeder to additionally supply the compressed air at a third predetermined ratio when the variation of the rotor is equal to or less than a preset threshold value.

Here, the compressed air control section sets the third set amount ratio so as to be proportional to (the first set amount) X (the inflection point rotation speed - the measured rotation speed) / (the inflection point rotation speed).

Further, the compressed air control unit may include:

Wherein the third set amount ratio is set to be proportional to (the first set amount) X (inflection point load amount - current load amount) / (inflection point load amount), and the inflection point load amount is set such that the exhaust gas temperature is the set threshold It indicates the load when the change starts to a lower value.

In addition, the compressed air control unit increases the amount of the compressed air supplied to the turbine when the exhaust gas temperature rises.

According to an aspect of the present invention, there is provided a compressor comprising: a compressor for sucking and compressing air according to the present invention; a feeder for supplying compressed air compressed by the compressor to a combustor and a turbine; A method of controlling a gas turbine system having a combustor and a turbine rotating by a combustion gas generated in the combustor, the turbine being driven by rotation of the turbine, Measuring the exhaust gas temperature representing the temperature of the exhaust gas discharged from the turbine, and measuring the amount of the compressed air supplied to the turbine based on the rotational speed of the rotor provided in the measured turbine and the exhaust gas temperature Wherein the step of controlling the feeder further comprises the step of controlling the feeder gas temperature Supplying the compressed air of the first predetermined amount when the exhaust gas temperature is equal to or lower than the set threshold value; determining whether the exhaust gas temperature is the set threshold value and the rotational speed of the rotor is the inflection point rotational speed- And controlling the feeder to additionally supply the compressed air at a third predetermined ratio when the variation of the rotor is equal to or less than a predetermined threshold at the threshold value.

Here, the step of controlling the feeder to additionally supply the compressed air at the third set amount ratio may further include the step of setting the third set amount ratio as (the first set amount) X (the inflection point rotational speed-measured rotational speed) / (The inflection point rotation speed).

The step of controlling the feeder to additionally supply the compressed air at the third predetermined amount ratio may further include a step of controlling the supply amount of the compressed air based on the third preset amount ratio (the first predetermined amount) X (inflection point loading amount - current load amount) ), And the inflection point load amount represents a load amount at which the exhaust gas temperature starts changing from the set threshold value to a value lower than the set threshold value.

According to the present invention, it is possible to complete combustion in a combustor even under a low load condition, thereby reducing the amount of noxious gas discharged.

According to the present invention, it is possible to reduce the temperature of the exhaust gas discharged from the turbine by adjusting the amount of compressed air for cooling supplied to the turbine.

1 is a diagram illustrating a gas turbine system according to one embodiment of the present invention.
2 is a graph showing the relationship between the intake temperature of the turbine 20 and the temperature of the exhaust gas according to the load.
3 is a diagram illustrating the structure of a control apparatus 100 according to an embodiment of the present invention.
4 is a diagram showing the control result by the control device of the present invention.
5 is a view showing a control method of the control apparatus 100 of the gas turbine system according to the embodiment of the present invention.
6 is a diagram illustrating a control method of the control apparatus 100 of the gas turbine system when the turbine inlet temperature of the combustion gas can not be measured according to an embodiment of the present invention.

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 a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when a part is referred to as "including " an element, it does not exclude other elements unless specifically stated otherwise.

If any part is referred to as being "on" another part, it may be directly on the other part or may be accompanied by another part therebetween. In contrast, when a section is referred to as being "directly above" another section, no other section is involved.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

Terms indicating relative space such as "below "," above ", and the like may be used to more easily describe the relationship to other portions of a portion shown in the figures. These terms are intended to include other meanings or acts of the apparatus in use, as well as intended meanings in the drawings. For example, when inverting a device in the figures, certain portions that are described as being "below" other portions are described as being "above " other portions. Thus, an exemplary term "below" includes both up and down directions. The device can be rotated by 90 degrees or rotated at different angles, and terms indicating relative space are interpreted accordingly.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

1 is a diagram illustrating a gas turbine system according to one embodiment of the present invention.

1, a gas turbine system may include a compressor 10, a feeder 50, a combustor 30, a turbine 20, and a controller 100,

The compressor 10 can perform the function of sucking and compressing the outside air to generate high-pressure air. Compressed air can be delivered to the combustor 30 by a feeder 50 and some compressed air can be delivered to the turbine 20 and used to cool the turbine. At this time, the compressed air to the turbine can be delivered to the turbine 20 after the temperature is lowered through a cooler (not shown) to lower the temperature of the air.

The combustor 30 injects fuel into the compressed air coming from the compressor 10 and burns it to generate a high-pressure, high-temperature combustion gas and provide it to the turbine 20. The high-temperature, high-pressure combustion gas supplied to the turbine 20 drives a rotor of the turbine to rotate the rotor of the turbine 20. The high-temperature, high-pressure combustion gas supplied to the turbine 20 lowers temperature and pressure while driving the rotor blades of the turbine, and is discharged to the atmosphere as exhaust gas.

The turbine 20 and the compressor 10 are fixed to one shaft 40 so that the compressor 10 can be rotated while the rotor of the turbine 20 rotates as described above.

In general, the control device 100 can perform various controls for efficiently driving the gas turbine system. In the present invention, a method of controlling the feeder 50 to adjust the amount of compressed air supplied to the turbine 20 .

Generally, the gas turbine system can combust the fuel to rotate the rotor of the turbine 20 to perform power generation, which generates harmful exhaust gas as described above. In order to minimize the generation of harmful exhaust gases, it is necessary to completely combust the injected fuel. That is, the temperature at the inlet of the turbine 20 of the combustion gas generated in the combustor can be kept as high as possible and constant, thereby minimizing the generation of harmful exhaust gas. And the output of the gas turbine system can be directly controlled by controlling a fuel valve that controls the amount of fuel entering the combustor 30. [

That is, the controller 100 can control the gas turbine system to operate efficiently based on the turbine inlet temperature and the exhaust gas temperature of the combustion gas.

2 is a graph showing the relationship between the intake temperature of the turbine 20 and the temperature of the exhaust gas according to the load.

In a general situation, the gas turbine system seeks to maintain the turbine inlet temperature as high as possible and constant, in order to obtain optimal efficiency and minimal hazardous emissions. The limit of the turbine inlet temperature can be determined by the durability to the temperature of the turbine and the combustor. That is, the turbine inlet temperature can be set to the maximum temperature at which the components of the turbine and / or combustor may be unaffected, and the control device 100 can be configured to control the compressor The air amount and the fuel amount can be determined and controlled.

However, referring to FIG. 2, the larger the load, the lower the exhaust gas temperature 220 while keeping the turbine inlet temperature 210 constant. Conversely, the smaller the load, the higher the exhaust gas temperature 220 while maintaining the turbine inlet temperature 210 constant. This is because the rotation of the rotor in the turbine 20 is reduced in accordance with the load and the thermal energy consumed is reduced. That is, as the load becomes smaller in the combustion gas flowing into the turbine at the same temperature, the exhaust gas temperature 220 becomes larger because the heat energy consumed becomes smaller. And the exhaust gas temperature 220 can not be increased beyond the threshold value due to environmental regulations or the like. That is, when the concentration exceeds the critical value, the amount of the harmful exhaust gas deviates from the controllable range, and the harmful gas exceeding the regulated range can be discharged.

Accordingly, the control device 100 controls to lower the turbine inlet temperature 210 of the combustion gas so as to prevent the exhaust gas temperature 220 from rising above the threshold value. That is, in the partial load state 211 where the load is less than the maximum producible load, the turbine inlet temperature 210 can be controlled to be lowered to prevent the exhaust gas temperature 220 from rising above the threshold value. However, if the turbine inlet temperature 210 is lowered, the efficiency of the gas turbine system is lowered, and the incomplete combustion of the fuel may contain more harmful substances in the exhaust gas. In order to prevent this, it is necessary to lower the exhaust gas temperature 220 while controlling the turbine inlet temperature 210 to be maintained at the maximum value.

3 is a diagram illustrating the structure of a control apparatus 100 according to an embodiment of the present invention.

Referring to FIG. 3, the controller 100 may include a sensing unit 110 and a compressed air controller 120. The sensing unit 110 may measure the turbine inlet temperature 210 and the exhaust gas temperature 220. Also, the number of rotations of the rotor in the turbine 20 can be measured and the load can be estimated based on the measured number of rotations.

The compressed air control unit 120 controls the amount of compressed air flowing into the combustor 30 and the turbine 20 based on the turbine inlet temperature 210, the exhaust gas temperature 220, and / or the load measured by the sensing unit 110 Can be controlled. The compressed air control unit 120 controls the amount of compressed air introduced into the combustor 30 to maintain the turbine inlet temperature 210 at a maximum value when the exhaust gas temperature 220 rises while the load is reduced give. In addition, the compressed air control unit 120 controls the supply of the compressed air to the turbine 20 to increase the amount of compressed air supplied to the turbine 20 for cooling the turbine 20, 50 can be controlled. Thereby, the combustion gas introduced into the turbine can be further cooled, thereby lowering the temperature of the exhaust gas. At this time, the amount of compressed air to be increased can be determined based on the currently measured turbine inlet temperature. In one embodiment, the amount of compressed air to be supplied can be increased in proportion to the ratio obtained by (maximum value of turbine inlet temperature - current turbine inlet temperature) / (maximum value of turbine inlet temperature).

As described above, by increasing the amount of compressed air supplied to the turbine, the temperature of the exhaust gas can be controlled below the threshold value without further lowering the exhaust gas temperature and accordingly lowering the turbine inlet temperature.

4 is a diagram showing the control result by the control device of the present invention.

Comparing FIG. 4 with FIG. 2 in the low load region 213, it can be seen that the turbine inlet temperature 210 can be maintained at a maximum value even if the exhaust gas temperature 220 is close to the threshold value. Thus, the fuel can be completely burned and the emission of noxious gas can be minimized.

5 is a view showing a control method of the control apparatus 100 of the gas turbine system according to the embodiment of the present invention.

Referring to FIG. 5, the controller 100 of the gas turbine system according to an embodiment of the present invention first measures the turbine inlet temperature and the exhaust gas temperature using the sensing unit 110 or the like (S510). In normal normal operation, the turbine inlet temperature may be around the maximum and the exhaust gas temperature may be below the threshold. When the exhaust gas temperature is below the threshold value, the controller 100 can control so that the first predetermined amount of compressed air is continuously supplied to the turbine 20 (S520). However, when the rotational speed of the rotor of the turbine 20 is reduced due to the reduction of the required load, the exhaust gas temperature is increased. Then, when the exhaust gas temperature reaches the threshold value and the turbine inlet temperature becomes the maximum value or less, the compressed air supply can be increased at the second predetermined ratio (S530). At this time, the second set amount ratio can be set based on the measured turbine inlet temperature. In one embodiment, the ratio can be set to a value obtained by (maximum value of turbine inlet temperature - current turbine inlet temperature) / (maximum value of turbine inlet temperature).

On the other hand, although it has been assumed in the above description that the turbine inlet temperature can be measured, the turbine inlet temperature may be too high to be measurable. In this case, the turbine inlet temperature can be estimated based on the load and the exhaust gas temperature.

 That is, the control apparatus 100 of the gas turbine system can estimate the turbine inlet temperature based on the exhaust gas temperature and the load with reference to FIG. Therefore, in the state 211 where the exhaust gas temperature is at the threshold and the load is small, it can be determined that the turbine inlet temperature is below the maximum value. At this time, the controller 100 may set an additional ratio of the compressed air to be supplied to the turbine based on the load or the rotational speed of the rotor 20. In one embodiment, based on the load at the point (A) at which the turbine inlet temperature is at its maximum value and the exhaust gas temperature decreases at the threshold value in the normal state and the current load (B) (A point load - current load amount) / ) Of the compressed air to be supplied to the turbine can be set in proportion to the value obtained by the following equation.

6 is a diagram illustrating a control method of the control apparatus 100 of the gas turbine system when the turbine inlet temperature of the combustion gas can not be measured according to an embodiment of the present invention.

Referring to FIG. 6, the controller 100 of the gas turbine system according to an embodiment of the present invention first measures a load and an exhaust gas temperature using the sensing unit 110 or the like (S610). In normal normal operation, the turbine inlet temperature may be around the maximum and the exhaust gas temperature may be below the threshold. When the exhaust gas temperature is below the threshold value, the controller 100 can control so that the first predetermined amount of compressed air is continuously supplied to the turbine 20 (S620). However, when the rotational speed of the rotor of the turbine 20 is reduced due to the reduction of the required load, the exhaust gas temperature is increased. Then, when the exhaust gas temperature reaches the threshold value and the load becomes smaller than the load at the inflection point A, that is, at the point where the exhaust gas temperature starts to change from the threshold value to the low value, the compressed air supply is increased at the third predetermined amount ratio (S630). At this time, the third set amount ratio can be set based on the measured load amount. In one embodiment, the third set amount ratio can be set in proportion to a ratio obtained from (A point load - current load) / (A point load). Alternatively, the load and the rotational speed of the rotor of the turbine may be set in proportion to the ratio obtained from (A point rotational speed - current rotational speed) / (A point rotational speed) since they provide the same physical concept.

As described above, the present invention proposes a control device for controlling the temperature of the turbine inlet, which indicates the temperature of the combustion gas introduced into the turbine, to have a maximum value. The use of such a control device can reduce the amount of harmful exhaust gas discharged from the gas turbine system Can be minimized.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. Only. It is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. .

10: Compressor
20: Turbine
30: Combustor
40:
50: Feeder
100: Control device
110: sensing unit
120: Compressed air control unit

Claims (7)

A compressor for sucking and compressing air, a feeder for supplying compressed air compressed by the compressor to a combustor and a turbine, a combustor for generating high temperature and high pressure combustion gas by burning the compressed air and fuel, A control device of a gas turbine system having a turbine rotating by gas and driving a generator by rotation of the turbine,
A sensing unit for measuring the temperature of the exhaust gas, which indicates the rotational speed of a rotor provided in the turbine and the temperature of the exhaust gas discharged from the turbine; And
And a compressed air control unit for controlling the feeder to adjust the amount of compressed air supplied to the turbine based on the rotational speed of the rotor and the temperature of the exhaust gas measured by the sensing unit,
The compressed air control unit includes:
The exhaust gas temperature is the set threshold value, the rotation speed of the rotor is the inflection point rotation speed, and the inflection point rotation speed is a temperature at which the exhaust gas temperature is lower than the predetermined threshold, Wherein the control unit controls the feeder to additionally supply compressed air at a third predetermined ratio when the change in the rotor speed is detected when the change from the set threshold value to the set threshold value begins.
Gas turbine control device. The method according to claim 1,
The compressed air control unit includes:
(The first set amount) X (the inflection point rotation speed - the measured rotation speed) / (the inflection point rotation speed)
Gas turbine control device. The method according to claim 1,
The compressed air control unit includes:
The third set amount ratio is set to be proportional to (the first set amount) X (inflection point load amount - current load amount) / (inflection point load amount)
Wherein the inflection point load amount indicates a load amount at which the exhaust gas temperature starts to change from the set threshold value to a value lower than the set threshold value. The method according to claim 1,
The compressed air control unit includes:
And increasing the amount of compressed air supplied to the turbine as the exhaust gas temperature rises,
Gas turbine control device. A compressor for sucking and compressing air, a feeder for supplying compressed air compressed by the compressor to a combustor and a turbine, a combustor for generating high temperature and high pressure combustion gas by burning the compressed air and fuel, A method of controlling a gas turbine system having a turbine rotating by gas and driving a generator by rotation of the turbine,
Measuring an exhaust gas temperature indicative of a rotational speed of a rotor provided in the turbine and a temperature of an exhaust gas discharged from the turbine; And
And controlling the feeder to adjust the amount of compressed air supplied to the turbine based on the measured rotational speed of the rotor and the exhaust gas temperature of the turbine,
Wherein the step of controlling the feeder comprises:
Supplying a first predetermined amount of compressed air when the exhaust gas temperature is equal to or lower than a set threshold value; And
Wherein the exhaust gas temperature is the set threshold value and the rotational speed of the rotor is the inflection point rotational speed-inflection point rotational speed is a rotational speed of the rotor when the exhaust gas temperature starts to change from the set threshold value to a value lower than the set threshold value - controlling the feeder to additionally supply compressed air at a third set rate,
Gas turbine control method. 6. The method of claim 5,
Wherein the step of controlling the feeder to additionally supply compressed air at the third predetermined amount ratio comprises:
And setting the third set amount ratio to be proportional to (the first set amount) X (inflection point rotational speed - measured rotational speed) / (inflection point rotational speed)
Gas turbine control method. 6. The method of claim 5,
Wherein the step of controlling the feeder to additionally supply compressed air at the third predetermined amount ratio comprises:
The third set amount ratio is set to be proportional to (the first set amount) X (inflection point load amount - current load amount) / (inflection point load amount)
Wherein the inflection point load amount represents a load amount at which the exhaust gas temperature starts to change from the set threshold value to a value lower than the set threshold value,
Gas turbine control method.

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