JP2016161157A - Gas turbine combustor, gas turbine, and operational method of the gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine combustor capable of improving the cooling of a liner while maintaining high combustion efficiency in a range from no load condition toward a partial load condition of the gas turbine.SOLUTION: A gas turbine combustor comprises: a liner 21 forming a combustion chamber 30 inside; a burner 22 provided in one end of the liner 21 in an axial direction; a burner cylinder 23 that internally capsules the liner 21 and the burner 22; a bypass air acceptance part 41 provided within the burner cylinder 23 so as to surround a predetermined region including an end part on the burner side of the liner 21 and to form an annular space together with the liner 21; a by-pass piping 42 for bypassing part of compressed air from a compressor 1 to the bypass air acceptance part 41 as bypass air; and a bypass valve 43 capable of regulating the flow rate of the bypass air flowing through the by-pass piping 42, in which the liner 21 includes a bypass air hole 48 formed at a predetermined position in a region surrounded by the bypass air acceptance part 41, the bypass air hole communicating a space within the bypass air acceptance part 41 with the combustion chamber 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas turbine combustor, a gas turbine including the same, and a method for operating the gas turbine.

  A fuel having a low calorific value is generally a fuel that is difficult to burn because the flame temperature is low and the combustion speed is slow compared to LNG (Liquefied Natural Gas) or the like. A typical example of such a low calorie gas is blast furnace gas. The blast furnace gas is a by-product gas generated from the blast furnace in the iron making process, and is a flame retardant gas containing carbon monoxide and hydrogen as main combustible components and a large amount of nitrogen and carbon dioxide. There is a need to use this blast furnace gas as fuel for a gas turbine.

  In a gas turbine combustor, generally, the fuel flow rate is lower during partial load operation of the gas turbine, particularly during low load operation, and therefore the combustion temperature is lower than during rated load operation. At low combustion temperatures, the reactivity of the fuel decreases, so the combustion efficiency tends to decrease. In particular, when blast furnace gas, which is a flame-retardant gas, is used as a fuel, if the reactivity of the fuel decreases, the fuel becomes incompletely combusted, and a decrease in combustion efficiency becomes a problem.

  Therefore, in order to improve combustion efficiency during partial load operation, a part of the compressed air from the compressor is bypassed so as to flow into the turbine without flowing into the combustor, thereby reducing the fuel concentration in the combustor. There is a way to increase the combustion temperature. As an example of a gas turbine having such a bypass structure, a casing that forms a chamber that receives compressed air from a compressor, a combustor formed by a cylindrical liner disposed in the chamber, and a combustor A connecting duct that is connected to the end and delivers combustion gas generated in the combustor to the turbine, and an air connected to the connecting duct so that a part of the compressed air received in the chamber can bypass the combustor. There is a type equipped with a bypass valve device and supply means for supplying control air at a variable pressure from a compressor to a pneumatic bypass valve device (see Patent Document 1).

JP-A-8-49566

  In the gas turbine described in Patent Document 1 described above, during partial load operation, a part of the compressed air from the compressor bypasses the combustor and flows into the communication duct on the downstream side of the combustor. The flow rate of the compressed air flowing along the outer surface of the combustor is reduced. The compressed air has a function of cooling the liner heated by the combustion gas generated in the combustor when flowing along the outer surface of the liner. Therefore, if the compressed air flowing along the outer surface of the liner is reduced by bypass, the liner may be insufficiently cooled.

  The present invention has been made to solve the above-described problems, and its purpose is to improve the cooling of the liner while maintaining high combustion efficiency from a no-load condition to a partial load condition of the gas turbine. An object of the present invention is to provide a gas turbine combustor, a gas turbine, and a method for operating the gas turbine.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above-described problems. For example, a cylindrical liner that forms a combustion chamber therein, a burner provided at one end in the axial direction of the liner, and the liner And an outer cylinder that encloses the burner, and a bypass air receiving portion that is installed in the outer cylinder so as to surround a predetermined region including the burner side end of the liner, and forms an annular space with the liner, One end is connected to the bypass air receiving portion, and a bypass pipe for bypassing a part of the compressed air from the compressor to the bypass air receiving portion as bypass air is installed in the bypass pipe and flows through the bypass pipe A bypass valve capable of adjusting the flow rate of the bypass air, and the liner is disposed at a predetermined position in a region surrounded by the bypass air receiving portion. And having a bypass air hole communicating with the space in the put portion and with said combustion chamber.

According to the present invention, the bypass pipe for bypassing a part of the compressed air as the bypass air is connected to the bypass air receiving portion surrounding the predetermined region including the burner side end portion of the liner, and at a predetermined position of the liner. By providing the bypass air hole, the bypass air can cool the region surrounded by the bypass air receiving portion of the liner and flow into a predetermined position of the combustion chamber. In this case, it is possible to improve the cooling of the liner while maintaining high combustion efficiency.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS It is the longitudinal cross-sectional view which shows 1st Embodiment of the gas turbine combustor of this invention, and a schematic block diagram which shows a gas turbine provided with the same. It is the longitudinal cross-sectional view which expanded the bypass air receiving part which comprises a part of 1st Embodiment of the gas turbine combustor of this invention shown with the code | symbol A of FIG. It is a characteristic view which shows the relationship between the integral opening area of the liner which comprises a part of 1st Embodiment of the gas turbine combustor of this invention shown in FIG. 1, and an axial direction position. It is explanatory drawing which shows the predetermined position of the bypass air hole provided in the liner which comprises a part of 1st Embodiment of the gas turbine combustor of this invention shown in FIG. It is a characteristic view which shows the relationship between the gas turbine load and the valve opening degree of a bypass valve in the operating method of the gas turbine provided with 1st Embodiment of the gas turbine combustor of this invention shown in FIG. It is a characteristic view which shows the relationship between the theoretical flame temperature and the equivalent ratio in typical blast furnace gas. It is a characteristic view which shows the relationship between the gas turbine load and the equivalence ratio in the operating method of the gas turbine provided with 1st Embodiment of the gas turbine combustor of this invention shown in FIG. It is a characteristic view which shows the relationship between the axial direction position of a liner in the case of a no-load condition in the operating method of the gas turbine provided with 1st Embodiment of the gas turbine combustor of this invention shown in FIG. 1, and an equivalence ratio. . It is a characteristic view which shows the relationship between the axial direction position of a liner in the case of the rated load condition in the operating method of the gas turbine provided with 1st Embodiment of the gas turbine combustor of this invention shown in FIG. 1, and an equivalence ratio. . It is the longitudinal cross-sectional view which shows 2nd Embodiment of the gas turbine combustor of this invention, and a schematic block diagram which shows a gas turbine provided with the same.

Embodiments of a gas turbine combustor, a gas turbine, and a gas turbine operating method according to the present invention will be described below with reference to the drawings. [First Embodiment]
A gas turbine combustor, a gas turbine, and a gas turbine operating method according to a first embodiment of the present invention will be described with reference to FIGS.
First, the configuration of a first embodiment of a gas turbine combustor of the present invention and a gas turbine including the gas turbine combustor will be described with reference to FIGS. 1 to 3. FIG. 1 is a longitudinal sectional view showing a first embodiment of a gas turbine combustor according to the present invention and a schematic configuration diagram showing a gas turbine having the same, and FIG. 2 is a gas turbine combustion according to the present invention indicated by reference A in FIG. FIG. 3 is an enlarged longitudinal sectional view of a bypass air receiving portion constituting a part of the first embodiment of the combustor, and FIG. 3 is a part of the first embodiment of the gas turbine combustor of the present invention shown in FIG. FIG. 6 is a characteristic diagram showing a relationship between an integrated opening area of the liner constituting the shaft and an axial position. In FIG. 1, the arrows indicate the flow direction of the working fluid or fuel of the gas turbine. In FIG. 2, arrows indicate the flow direction of bypass air or combustion air. In FIG. 3, the vertical axis S represents the integrated opening area of the cooling air holes 31 and the bypass air holes 48 of the liner 21 shown in FIG. Indicates the position. 1 and 2, the combustor is illustrated such that the left side is the upstream side of the combustion gas and the right side is the downstream side.

  In FIG. 1, the gas turbine mixes and burns a compressor 1 that compresses air to generate high-pressure compressed air 100, and compressed air 100 and fuel 200 that are introduced from the compressor 1. Are provided with a combustor 2 that generates a combustion gas 110 and a turbine 3 that obtains a shaft driving force by the energy of the combustion gas 110 generated by the combustor 2. A generator 4 is mechanically connected to the gas turbine. An air flow rate detector 8 that detects the flow rate of the compressed air 100 is provided at the outlet of the compressor 1. A fuel system 10 that supplies fuel 200 is connected to the combustor 2. The fuel system 10 includes a fuel flow rate detector 11 that detects the fuel flow rate. Examples of the fuel 200 include a blast furnace gas having a low calorie gas.

  The combustor 2 is provided with a substantially cylindrical liner 21 that forms a combustion chamber 30 therein, and one end of the liner 21 in the axial direction (the left end in FIG. 1), and a part of the fuel 200 and the compressed air 100 is used as combustion air. 101, a burner 22 that is injected into the combustion chamber 30, a liner 21 and an outer cylinder 23 as a pressure vessel containing the burner 22, the other axial end of the liner 21 (the right end in FIG. 1), and the turbine 3 are connected. A transition piece 24 that guides the combustion gas 110 generated in the combustion chamber 30 to the turbine 3 and an end cover 25 that closes an opening at one end (the left end in FIG. 1) of the outer cylinder 23 on the burner 22 side are provided. The other end (the right end in FIG. 1) of the outer cylinder 23 is connected to the casing 6. A space 7 into which the compressed air 100 flows from the compressor 1 is formed inside the casing 6. The combustor 2 is configured such that compressed air 100 flows from the compressor 1 through the casing 6.

  An annular channel 32 through which the compressed air 100 flows is formed between the outer cylinder 23 and the liner 21. In the region on the right side of the liner 21 (downstream of the combustion gas 110), there are a plurality of cooling air holes 31 through which a part of the compressed air 100 flows into the combustion chamber 30 as the cooling air 102 of the liner 21 in the axial direction and the circumferential direction. Is provided. This right region is, for example, about two-thirds of the entire length from the right end.

  The combustor 2 further includes a bypass mechanism 40 that bypasses a part of the compressed air 100 as bypass air 103 and flows into a predetermined position of the combustion chamber 30 in the combustor 2. As shown in FIGS. 1 and 2, the bypass mechanism 40 is installed in the annular flow path 32 so as to surround a predetermined region including the left end portion (burner 22 side end portion) of the liner 21, and is annular with the liner 21. The bypass air receiving portion 41 that forms the space 47 and one end (right end in FIG. 1) are connected to the casing 6 and extend to the outside of the casing 6, and the other end (left end in FIG. 1) is the outer cylinder 23. And a bypass air pipe 42 connected to the bypass air receiving portion 41 and a bypass valve 43 installed in the bypass air pipe 42. The predetermined region of the liner 21 surrounded by the bypass air receiving portion 41 is a region including a portion provided with a bypass air hole 48 to be described later, for example, from the left end portion of the liner 21 to about one third of the entire length. It is a part of.

  The bypass air pipe 42 bleeds a part of the compressed air 100 from the compressor 1 as bypass air 103 and bypasses it to the bypass air receiving portion 41. As shown in FIG. 2, the bypass air pipe 42 is connected to the left end portion of the bypass air receiving portion 41. A substantially cylindrical impingement member 45 facing the liner 21 is installed in the space 47 in the bypass air receiving portion 41. The impingement member 45 has a plurality of impingement holes 49 for ejecting the bypass air 103 to the outer surface of the liner 21 in the axial direction and the circumferential direction.

  As shown in FIGS. 1 and 2, the space 47 in the bypass air receiving portion 41 communicates with the combustion chamber 30 at a predetermined position in the axial direction of the liner 21, and the bypass air 103 flows into the combustion chamber 30. A plurality of bypass air holes 48 are provided in the circumferential direction. That is, the liner 21 has a plurality of bypass air holes 48 at a predetermined position in the region surrounded by the bypass air receiving portion 41, for example, at the right end of the region. As shown in FIGS. 1 and 3, only the bypass air hole 48 is provided at the right end of the region surrounded by the bypass air receiving part 41 of the liner 21, and the cooling air hole 31 is provided. Not. As will be described in detail later, the predetermined position in the axial direction of the liner 21 is a position where the combustion temperature does not decrease and the combustion efficiency of the combustor 2 does not decrease even when the bypass air 103 flows into the combustion chamber 30. . For example, it is a position separated from the left end of the liner 21 by about one third of the entire length.

  In FIG. 1, the bypass valve 43 adjusts the flow rate of the bypass air 103 flowing through the bypass pipe 42. A controller 44 is connected to the bypass valve 43. The control device 44 is connected to the fuel flow rate detector 11 and the air flow rate detector 8, and the detection signal corresponding to the flow rate detected by the fuel flow rate detector 11 and the air flow rate detector 8 are detected. Detection signals corresponding to the flow rates are respectively input. The control device 44 controls the valve opening degree of the bypass valve 43 based on the fuel flow rate detected by the fuel flow rate detector 11, the compressed air flow rate detected by the air flow rate detector 8, and the load condition of the gas turbine. The flow rate of the bypass air 103 is adjusted.

Next, a predetermined position in the axial direction of the liner in which the bypass air hole is provided will be described with reference to FIG.
FIG. 4 is an explanatory view showing a predetermined position of a bypass air hole provided in a liner constituting a part of the first embodiment of the gas turbine combustor of the present invention shown in FIG. It is a characteristic view which shows the rough relationship between the flame temperature at the time of burning by 1.0, and the axial direction position of a liner. In FIG. 4, the vertical axis T is the flame temperature (° C.) when a typical blast furnace gas burns at an equivalence ratio of 1.0, and the horizontal axis x is the axis where the left end of the liner 21 (the burner 22 side end) is zero. The direction position is shown. The equivalence ratio is an index representing the concentration of fuel with respect to air, and is a value obtained by dividing the theoretical air-fuel ratio by the actual air-fuel ratio of the air-fuel mixture. In FIG. 4, the same reference numerals as those shown in FIGS. 1 to 3 are the same parts, and detailed description thereof is omitted.

  When the fuel having the equivalence ratio of 1.0 reacts with the combustion air, as shown in FIG. 4, the flame temperature T is in the state of several hundred degrees C. which is considerably lower than 1000 degrees C. from the left end 0 to a certain position x. As you go further to the right, it will gradually rise. It reaches about 1000 ° C. at a certain axial position h, and becomes substantially constant at over 1000 ° C. on the right side.

  If the bypass air is caused to flow into the combustion chamber from the position x where the flame temperature T does not reach 1000 ° C., the bypass air prevents the combustion temperature from rising and the fuel reactivity decreases. That is, the meaning of bypassing compressed air is lost. On the other hand, when the bypass air is introduced from the position x where the flame temperature T has reached 1000 ° C. or higher, the bypass air does not lower the increased combustion temperature, but becomes a new oxygen supply source and promotes combustion. .

  Therefore, in the present embodiment, for example, the bypass air hole is provided at the axial position of the liner 21 where the fuel having the equivalence ratio of 1.0 reacts with the combustion air and the combustion temperature can reach 1000 ° C. or higher. 48 is provided. By providing the bypass air hole 48 at such a position, even if the bypass air 103 flows into the combustion chamber 30, the combustion temperature does not decrease, and high combustion efficiency can be maintained. That is, the predetermined position where the bypass air hole is provided is a position where the combustion efficiency is not lowered even if the bypass air 103 flows into the combustion chamber 30.

Next, the flow of the working fluid in the first embodiment of the gas turbine including the gas turbine combustor of the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the gas turbine compresses the air taken in from the atmosphere by the compressor 1 and supplies the compressed air 100 to the space 7 in the casing 6. A part of the compressed air 100 flows into an annular flow path 32 formed between the liner 21 and the outer cylinder 23, and the rest flows into the bypass air pipe 42 as bypass air 103.

  The compressed air 100 flowing into the annular flow path 32 flows toward the burner 22 and cools the outer surface of the liner 21 at this time. Part of this compressed air 100 reaches the left end of the combustor 2, collides with the end cover 25, changes the flow direction, and flows into the burner 22 as combustion air 101. The combustion air 101 that has flowed into the burner 22 is given a swirl component, is injected into the combustion chamber 30, and is mixed with the fuel 200 injected from the burner 22. Thereby, the diffusion flame 105 is formed and the combustion gas 110 is generated. Further, the other portion of the compressed air 100 that has flowed into the annular flow path 32 flows into the combustion chamber 30 from the cooling air hole 31 as cooling air 102. The cooling air 102 suppresses the temperature rise of the liner 21 due to the high-temperature combustion gas 110. For example, the cooling air 102 flows into the combustion chamber 30 along the axial direction of the liner 21.

  On the other hand, the bypass air 103 flows into the bypass air receiving portion 41 through the bypass air pipe 42. As shown in FIGS. 1 and 2, the bypass air 103 collides with the impingement member 45, and is ejected from the impingement hole 49 of the impingement member 45 and collides with the liner 21. Thereby, the portion of the liner 21 that is heated by the diffusion flame and becomes high temperature is impingement cooled. The bypass air 103 after colliding with the liner 21 flows through the gap between the liner 21 and the impingement member 45 toward the bypass air hole 48 on the downstream side (the right side in FIGS. 1 and 2), and from the bypass air hole 48 to the combustion chamber 30. Flow into. When this bypass air 103 flows along the outer surface of the liner 21, the liner 21 is cooled by heat transfer. That is, in the present embodiment, the portion of the liner 21 heated to a high temperature by the diffusion flame 105 is impingement cooled by the ejection of the bypass air 103 and cooled by heat transfer with the bypass air 103.

  The combustion gas 110 generated in the combustion chamber 30 is mixed with the cooling air 102 and the bypass air 103 flowing into the combustion chamber 30, passes through the transition piece 24, and flows into the turbine 3. By supplying the combustion gas 110, rotational power is given to the turbine 3, and the rotational power of the turbine 3 is transmitted to the compressor 1 and the generator 4. The rotational power transmitted to the compressor 1 is used as compression power, and the rotational power transmitted to the generator 4 is converted into electric energy.

Next, the operation method of the gas turbine provided with the first embodiment of the gas turbine combustor of the present invention will be described with reference to FIGS.
First, the relationship of the valve opening degree of the bypass valve with respect to the load condition of a gas turbine is demonstrated using FIG.
FIG. 5 is a characteristic diagram showing the relationship between the gas turbine load and the valve opening degree of the bypass valve in the operation method of the gas turbine provided with the first embodiment of the gas turbine combustor of the present invention shown in FIG. In FIG. 5, the vertical axis V represents the valve opening of the bypass valve, and the horizontal axis L represents the load (%) of the gas turbine. In FIG. 5, the same reference numerals as those shown in FIGS. 1 to 4 are the same parts, and detailed description thereof is omitted.

  As shown in FIG. 5, the control device 44 (see FIG. 1) sets the valve opening of the bypass valve 43 (see FIG. 1) to the maximum opening under the no-load condition (0%) of the gas turbine, and increases the load. In order to achieve a minimum opening degree under the rated load condition (100%). At this time, the amount of change in the valve opening relative to the amount of change in the load is lower in the low load condition (for example, less than about 40%) and in the high load condition (for example, more than about 60%). , About 40% or more and about 60% or less). The control device 44 adjusts the ratio of the combustion air 101 and the bypass air 103 by controlling the valve opening degree of the bypass valve 43, and finally the fuel 200 in the combustion chamber 30 and the combustion air 101 The ratio (equivalent ratio φ) is adjusted.

Next, the relationship of the equivalence ratio with respect to the load condition of a gas turbine is demonstrated using FIG.6 and FIG.7.
FIG. 6 is a characteristic diagram showing the relationship between the theoretical flame temperature and the equivalent ratio in typical blast furnace gas, and FIG. 7 is a diagram of a gas turbine equipped with the first embodiment of the gas turbine combustor of the present invention shown in FIG. It is a characteristic view which shows the relationship between the gas turbine load and equivalent ratio in an operation method. In FIG. 6, the vertical axis T represents the theoretical flame temperature (° C.) when a typical blast furnace gas is used, and the horizontal axis φ represents the equivalence ratio. In FIG. 7, the vertical axis φ represents the equivalence ratio, and the horizontal axis L represents the load (%) of the gas turbine. The equivalence ratio φ is a value at an axial position corresponding to the bypass air hole 48 in the liner 21 shown in FIG. A broken line α is a case where the valve opening degree of the bypass valve 43 is always fully closed, and a solid line β is a case where the bypass valve 43 is controlled as shown in FIG. 6 and 7, the same reference numerals as those shown in FIGS. 1 to 5 are the same parts, and the detailed description thereof will be omitted.

  When a typical blast furnace gas is used as the fuel 200, as shown in FIG. 6, the theoretical flame temperature T is highest when the equivalent ratio φ is around 1.0 (stoichiometric mixture ratio). That is, the theoretical flame temperature decreases as the equivalence ratio φ increases and decreases from around 1.0. From the viewpoint of this equivalence ratio and flame temperature, the following two types of operation methods are compared.

  First, when the bypass valve 43 (see FIG. 1) is fully closed regardless of the magnitude of the gas turbine load, that is, in the case of an operation method in which the compressed air 100 is not bypassed, as shown by the broken line α in FIG. φ increases as the load of the gas turbine increases. That is, when the fuel flow rate is increased in accordance with an increase in the load of the gas turbine, the equivalence ratio φ is increased due to the increase in the fuel flow rate. When the gas turbine load is from a no-load condition to a low-load condition, the fuel flow rate is small, so the equivalence ratio φ is sufficiently smaller than 1.0 (the stoichiometric mixture ratio). For this reason, as apparent from FIG. 6, the combustion temperature is lowered and the reactivity of the fuel 200 is lowered. For this reason, when a flame-retardant blast furnace gas is used as the fuel 200, incomplete combustion occurs, and the combustion efficiency decreases.

  On the other hand, in the operation method according to the present embodiment, as indicated by the solid line β in FIG. 7, in the no-load condition to the low-load condition of the gas turbine, the axial position corresponding to the bypass air hole 48 in the liner 21 is obtained. The valve opening degree of the bypass valve 43 is controlled by the control device 44 (see FIG. 1) so that the equivalence ratio becomes 1.0. Thereby, even when the fuel flow rate is small as in the no-load condition and the low-load condition, as shown in FIG. 6, the combustion temperature is not lowered, and the decrease in the reactivity of the fuel 200 can be prevented. For this reason, even if the flame-retardant fuel 200 is used, the combustion efficiency does not decrease.

  A specific example of the control will be described with reference to FIG. In FIG. 1, the control device 44 first takes in a detection signal detected by the fuel flow detector 11, a detection signal detected by the air flow detector 8, and a detection signal of the load condition of the gas turbine. Examples of the detection signal for the load condition of the gas turbine include a detection signal for the presence / absence of connection between the generator 4 and the gas turbine, a detection signal corresponding to the amount of power generated by the generator 4, or a detection signal corresponding to the fuel flow rate. . Based on such a detection signal, the control device 44 determines a load condition of the gas turbine. When the load of the gas turbine is a no-load condition or a low-load condition, the control device 44 has an equivalence ratio φ of 1.0 based on the detection signals of the fuel flow rate detector 11 and the air flow rate detector 8. A command to change the valve opening is output to the bypass valve 43. As a result, the flow rate of the bypass air 103 flowing through the bypass air pipe 42 is adjusted, and as a result, the flow rate of the combustion air 101 flowing into the combustion chamber 30 is adjusted.

Next, the relationship of the equivalence ratio with respect to the axial position of the liner (combustion chamber) in the no-load condition of the gas turbine and the operation method in the no-load condition of the gas turbine will be described with reference to FIGS. 1, 2, 6 and 8. .
FIG. 8 is a characteristic showing the relationship between the axial position of the liner and the equivalence ratio in the no-load condition in the operation method of the gas turbine provided with the first embodiment of the gas turbine combustor of the present invention shown in FIG. FIG. In FIG. 8, the vertical axis φ represents the equivalence ratio, and the horizontal axis x represents the axial position (%) with the left end (burner 22 side end) of the liner 21 (combustion chamber 30) shown in FIG. A broken line α is a case where the valve opening degree of the bypass valve 43 is fully closed, and a solid line β is a case where the bypass valve 43 is controlled as shown in FIG. In FIG. 8, the same reference numerals as those shown in FIGS. 1 to 7 are the same parts, and detailed description thereof is omitted.

  The equivalence ratio φ at the axial position 0 in the liner 21 (combustion chamber 30) shown in FIG. 1 is determined by the flow rates of the combustion air 101 and the fuel 200 flowing from the burner 22. Further, in the region from the axial position 0 to the bypass air hole 48 in the liner 21, since there is no hole penetrating the liner 21 in the radial direction (see FIGS. 1 and 2), as shown in FIG. The equivalence ratio φ of the region (C portion) is constant and is the same as the equivalence ratio of the axial position 0. Further, in the right side portion of the liner 21, the cooling air 102 flows into the combustion chamber 30 from the cooling air hole 31 (see FIG. 1), so that the equivalence ratio φ in the right side area in the liner 21 gradually increases toward the right side. descend.

  When the bypass valve 43 is fully closed, that is, in an operation method in which the compressed air 100 is not bypassed, the compressed air 100 flows into the combustion chamber 30 as combustion air 101 and cooling air 102 (see FIG. 1). For this reason, the flow rate of the combustion air 101 becomes large, and as shown by the broken line α in FIG. 8, the equivalent ratio φ in the region (C portion) from the left end in the liner 21 to the position corresponding to the bypass air hole 48. Is sufficiently lower than 1.0 (stoichiometric mixing ratio). Therefore, as described above, the combustion temperature is lowered and the combustion efficiency is lowered.

  On the other hand, in the operation method in the present embodiment, the bypass valve 43 is opened. Thereby, since the flow rate of the bypass air 103 increases, the flow rates of the combustion air 101 and the cooling air 102 decrease by the increased amount. For this reason, as shown by the solid line β in FIG. 8, the equivalent ratio φ of the region (C portion) in the liner 21 increases as compared with the case where the bypass valve 43 is fully closed.

  Further, in the operation method of the present embodiment, as indicated by the solid line β in FIG. 8, the control device 44 bypasses the equivalence ratio φ of the region (C portion) in the liner 21 to be 1.0. The valve opening degree of the valve 43 is controlled. When the equivalence ratio φ is 1.0, as shown in FIG. 6, the combustion temperature becomes high, so that the region in the liner 21 (combustion chamber 30) becomes high temperature. By forming a high temperature region in the combustion chamber 30, the combustion reaction between the combustion air 101 and the fuel 200 is promoted. Further, since the high temperature region is formed in a certain range in the axial direction, the time required for the combustion reaction between the combustion air 101 and the fuel 200 is secured. In this way, by controlling the valve opening degree of the bypass valve 43 with the control device 44 under no-load conditions, the region from the left end portion in the combustion chamber 30 to the position corresponding to the bypass air hole 48 is increased. Further, it is possible to prevent a decrease in the reactivity of the fuel 200 and to obtain high combustion efficiency.

  Thus, when the above-mentioned region of the combustion chamber 30 becomes high temperature, the portion of the liner 21 in that region also becomes high temperature according to the temperature of the combustion chamber 30, so it is necessary to cool that region of the liner 21. In the present embodiment, as shown in FIG. 2, the bypass air 103 flows into the bypass air receiving portion 41 that surrounds the region including the left end of the liner 21 to the bypass air hole 48 (the region that becomes high temperature). The impingement member 45 collides with the liner 21 as a collision jet. The temperature rise of the liner 21 is suppressed by impingement cooling by this impinging jet. Further, the bypass air 103 after colliding with the liner 21 flows toward the bypass air hole 48 along the outer surface of the liner 21. The bypass air 103 flowing along the outer surface of the liner 21 suppresses the temperature rise of the liner 21 due to heat transfer with the liner 21. That is, the temperature of the liner 21 can be suppressed by cooling the region of the liner 21 that has become high temperature by bypassing the compressed air 100 with the bypass air 103.

  Even when the gas turbine load is low, the same control as in the case of no load is performed. Therefore, the above-described effects can be obtained even under low load conditions.

Next, the relationship of the equivalence ratio with respect to the axial position of the liner (combustion chamber) in the rated load condition of the gas turbine, and the operation method in the rated load condition and high load condition of the gas turbine are shown in FIGS. And it demonstrates using FIG.
FIG. 9 is a graph showing the relationship between the axial position of the liner and the equivalence ratio in the rated load condition in the operating method of the gas turbine provided with the first embodiment of the gas turbine combustor of the present invention shown in FIG. FIG. In FIG. 8, the vertical axis φ represents the equivalence ratio, and the horizontal axis x represents the axial position (%) where the left end (burner 22 side end) of the liner 21 (combustion chamber 30) is zero. In FIG. 9, the same reference numerals as those shown in FIGS. 1 to 8 are the same parts, and detailed description thereof is omitted.

  In the rated load condition, the fuel flow rate increases compared to the low load condition, so the equivalence ratio φ becomes high. When the equivalence ratio φ is 3.0 or more, as shown in FIG. 6, the theoretical flame temperature is 1000 ° C. or less, so that there is a possibility that the flame becomes unstable due to insufficient oxygen and a decrease in the reactivity of the fuel 200. . Therefore, under the rated load condition, as shown in FIGS. 7 and 9, the opening degree of the bypass valve 43 is reduced by the control device 44 shown in FIG. 1 so that the equivalence ratio φ is less than 3.0. As a result, the flow rate of the bypass air 103 decreases, and as a result, the flow rate of the combustion air 101 flowing into the burner 22 increases. For this reason, it can suppress that the equivalent ratio (phi) of the area | region (C part of FIG. 9) from the left end part in the liner 21 to the position corresponding to the bypass air hole 48 becomes too high, and a flame becomes unstable.

  Also, in the high load condition, similarly to the rated load condition, the fuel flow rate increases compared to the low load condition, so the equivalence ratio φ becomes higher than in the low load condition. Therefore, even under a high load condition, the control device 44 controls the valve opening of the bypass valve 43 so as to become smaller according to the load (see FIG. 5).

  If the flow rate of the bypass air 103 is reduced by reducing the valve opening degree of the bypass valve 43 under the rated load condition and the high load condition, the impingement cooling efficiency of the bypass air 103 may be reduced and the temperature of the liner 21 may be increased. . Therefore, in the present embodiment, as shown in FIG. 7, the opening degree of the bypass valve 43 is controlled by the control device 44 so that the equivalence ratio φ of the region in the liner 21 is 1.5 or more. . In the fuel rich state where the equivalent ratio φ is 1.5, as shown in FIG. 6, the theoretical flame temperature is reduced by about 20% as compared with the case where the equivalent ratio φ is 1.0. That is, by setting the equivalence ratio φ to 1.5 or more, the combustion temperature is lowered, so that the heating of the liner 21 is suppressed. As described above, in the rated load condition and the high load condition, even if the flow rate of the bypass air 103 is small, the temperature rise of the liner 21 can be suppressed.

  In the present embodiment, from the no-load condition to the low-load condition, the flow rate of the bypass air 103 is increased by controlling the valve opening degree of the bypass valve 43 to be relatively larger than the rated load condition. The equivalent ratio φ of the region from the end portion on the burner 22 side in 21 to the position corresponding to the bypass air hole 48 is set to approximately 1.0. Thereby, while being able to obtain high combustion efficiency, the temperature rise of the liner 21 can be suppressed.

  On the other hand, under the rated load condition and the high load condition, the equivalence ratio φ is set to 1 by controlling the valve opening degree of the bypass valve 43 to be relatively smaller than the low load condition and reducing the flow rate of the bypass air 103. Make the fuel rich state between 5 and 3.0. Thereby, while being able to stabilize a flame, the temperature rise of the liner 21 can be suppressed.

  Under the medium load condition, the equivalence ratio φ is quickly switched from the stoichiometric mixture ratio to the fuel rich state by performing control to increase the amount of change in the valve opening of the bypass valve 43 (see FIG. 5).

  As described above, according to the first embodiment of the gas turbine combustor, the gas turbine, and the operation method of the gas turbine of the present invention, the bypass pipe 42 that bypasses a part of the compressed air 100 as the bypass air 103 is provided. The bypass air 103 is connected to a bypass air receiving portion 41 surrounding a predetermined region including the burner 22 side end portion of the liner 21 and a bypass air hole 48 is provided at a predetermined position of the liner 21, whereby the bypass air 103 is Since the region surrounded by the bypass air receiving portion 41 can be cooled and flow into a predetermined position of the combustion chamber 30, the liner 21 can be maintained while maintaining high combustion efficiency from a no-load condition to a partial load condition of the gas turbine. The cooling of the can be improved.

  Further, according to the present embodiment, since the bypass pipe 42 is connected to the left end portion (the end portion on the burner 22 side) of the bypass air receiving portion 41, the region surrounded by the bypass air receiving portion 41 of the liner 21. Can be reliably cooled by the bypass air 103.

  Furthermore, according to the present embodiment, since the bypass pipe 42 is extended to the outside of the outer cylinder 23, the bypass air 103 is cooled to the external atmosphere via the bypass pipe 42. For this reason, the temperature rise of the area | region enclosed by the bypass air reception part 41 of the liner 21 can further be suppressed.

  Further, according to the present embodiment, since the impingement member 45 is installed in the bypass air receiving portion 41, the bypass air 103 is ejected from the impingement hole 49 to the bypass air receiving portion 41 of the liner 21. The enclosed area can be efficiently cooled.

  Furthermore, according to the present embodiment, since the valve opening degree of the bypass valve 43 is controlled by the control device 44 in accordance with the load of the gas turbine, the flow rate of the bypass air 103 is appropriately maintained, and high combustion efficiency and liner 21 are achieved. Proper cooling can be reliably maintained.

[Second Embodiment]
Next, a second embodiment of the gas turbine combustor, the gas turbine, and the operation method of the gas turbine of the present invention will be described with reference to FIG.
FIG. 10 is a longitudinal sectional view showing a second embodiment of the gas turbine combustor of the present invention and a schematic configuration diagram showing a gas turbine including the same. In FIG. 10, arrows indicate the flow direction of the working fluid or fuel of the gas turbine. In FIG. 10, the same reference numerals as those shown in FIGS. 1 to 9 are the same parts, and detailed description thereof is omitted.

  A gas turbine combustor of the present invention shown in FIG. 10 and a gas turbine including the same are added to the configuration of the first embodiment, and the bypass air receiving portion 41 of the liner 21 is added to the configuration of the first embodiment. A temperature detector 50 for detecting the temperature of the enclosed region is further provided. Moreover, it replaces with the control apparatus 44 of 1st Embodiment, and the control apparatus 44A which controls the valve opening degree of the bypass valve 43 further considering the detected temperature of the temperature detector 50 is provided. The temperature detector 50 is connected to the control device 44A and outputs a detection signal corresponding to the detected temperature to the control device 44A. An example of the temperature detector 50 is a thermocouple.

  When blast furnace gas is used as the fuel 200, the fuel composition may change. In the first embodiment, when the calorific value of the fuel 200 increases due to a change in the fuel composition, the combustion temperature rises according to the increase in the calorific value, so that it is surrounded by the bypass air receiving portion 41 of the liner 21. The temperature in the affected area can also rise.

  Therefore, in the present embodiment, when the control device 44A determines that the detection signal of the temperature detector 50 has exceeded a predetermined set value, the control device 44A issues a command to change the valve opening according to the load of the gas turbine. Output to. That is, when the temperature of the liner 21 exceeds a predetermined temperature, the flow rate of the bypass air 103 is increased or decreased by changing the valve opening degree of the bypass valve 43 to lower the temperature of the liner 21.

  Specifically, the control device 44A first takes in the detection signals of the load conditions of the fuel flow detector 11, the air flow detector 8, and the gas turbine, respectively, as in the first embodiment, and the temperature detector 50. The detection signal is also captured. Next, it is determined whether or not the detection signal of the temperature detector 50 has exceeded a set value. When it is determined that the detection signal of the temperature detector 50 does not exceed the set value, the same control as in the first embodiment is performed.

  On the other hand, when it is determined that the detection signal of the temperature detector 50 has exceeded the set value and the load condition of the gas turbine is determined to be less than 50%, the control device 44A bypasses the command to decrease the valve opening. Output to valve 43. As a result, the flow rate of the combustion air 101 relatively increases due to the decrease in the flow rate of the bypass air 103, so that the region from the burner 22 side end in the liner 21 (combustion chamber 30) to the position corresponding to the bypass air hole 48. The equivalent ratio [phi] is lower than 1.0. When the equivalence ratio φ is less than 1.0, as shown in FIG. 6, the flame temperature rapidly decreases, so that the temperature rise of the liner 21 is suppressed.

  Further, when it is determined that the detection signal of the temperature detector 50 has exceeded the set value and it is determined that the load of the gas turbine is 50% or more, the control device 44A issues a command to increase the valve opening degree. Output to 43. Thereby, since the flow rate of the bypass air 103 increases, the impingement cooling efficiency of the liner 21 by the impingement member 45 and the cooling efficiency by heat transfer of the bypass air 103 are improved, and the cooling of the liner 21 is promoted. Further, since the flow rate of the combustion air 101 is relatively decreased due to the increase in the flow rate of the bypass air 103, the equivalence ratio φ becomes more fuel rich. When the fuel is richer, the flame temperature is lowered as shown in FIG. 6, so that the temperature rise of the liner 21 is suppressed.

  According to the second embodiment of the gas turbine combustor, the gas turbine, and the operation method of the gas turbine of the present invention described above, the same effects as those of the first embodiment described above can be obtained.

  Further, according to the present embodiment, the control device 44A controls the valve opening degree of the bypass valve 43 based on the temperature of the liner 21 detected by the temperature detector 50 and the load condition of the gas turbine. The temperature of the liner 21 can be lowered by increasing or decreasing the flow rate of the bypass air 103 with respect to the temperature rise of the liner 21 due to a change in the fuel composition or the like.

[Other Embodiments]
In the first and second embodiments described above, an example in which a low calorie gas such as blast furnace gas is used as the fuel has been shown, but even when a general fuel used in a gas turbine is used. Similar effects can be obtained.

  In the first and second embodiments described above, the bypass air receiving portion 41 is installed such that the bypass air hole 48 is located at the right end portion. May be installed so as to surround at least the region including the bypass air hole 48 from the end portion of the liner 21 on the burner 22 side. For example, the bypass air receiving portion 41 can be installed so as to surround the right air region beyond the position of the bypass air hole 48. The liner 21 in the region surrounded by the bypass air receiving portion 41 is cooled by the bypass air 103.

  In the first and second embodiments described above, the cooling air holes 31 are provided so that the cooling air 102 flows into the combustion chamber 30 along the axial direction of the liner 21. It is also possible to provide cooling air holes so that air swirls in the combustion chamber 30. As the cooling air swirls and flows into the combustion chamber 30, the swirl flow in the combustion chamber 30 is strengthened, and the stability of the flame can be increased.

  Further, the present invention is not limited to the first to second embodiments described above, and includes various modifications. The above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the configurations described. For example, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is also possible to add, delete, or replace another configuration for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Combustor, 3 ... Turbine, 21 ... Liner, 22 ... Burner, 23 ... Outer cylinder, 30 ... Combustion chamber, 41 ... Bypass air receiving part,
42 ... Bypass air piping, 43 ... Bypass valve, 44, 44A ... Control device,
45 ... Impingement member, 48 ... Bypass air hole, 49 ... Impingement hole,
50 ... temperature detector,

Claims (15)

A cylindrical liner that forms a combustion chamber inside;
A burner provided at one axial end of the liner;
An outer cylinder containing the liner and the burner;
A bypass air receiving portion installed in the outer cylinder so as to surround a predetermined region including the burner side end portion of the liner, and forming an annular space together with the liner;
One end is connected to the bypass air receiving portion, and bypass piping that bypasses a part of the compressed air from the compressor to the bypass air receiving portion as bypass air;
A bypass valve that is installed in the bypass pipe and is capable of adjusting a flow rate of bypass air flowing through the bypass pipe;
The liner has a bypass air hole that communicates the space in the bypass air receiving portion and the combustion chamber at a predetermined position in a region surrounded by the bypass air receiving portion. vessel. The gas turbine combustor according to claim 1.
The bypass pipe is connected to a burner side end of the bypass air receiving portion. A gas turbine combustor, wherein: The gas turbine combustor according to claim 1.
The gas turbine combustor, wherein the bypass pipe extends to the outside of the outer cylinder. The gas turbine combustor according to claim 1.
An impingement member installed in the space inside the bypass air receiving portion so as to face the liner;
The gas impingement member has a plurality of impingement holes for injecting bypass air flowing into the bypass air receiving portion to the outer surface of the liner. The gas turbine combustor according to claim 1.
A gas turbine combustor, further comprising: a control device that controls a valve opening degree of the bypass valve according to a load condition of the gas turbine. The gas turbine combustor of claim 5.
The control device controls the valve opening degree of the bypass valve so that the maximum opening degree is obtained when the load of the gas turbine is a no-load condition, is decreased as the load increases, and is the minimum opening degree under a rated load condition. A gas turbine combustor. The gas turbine combustor of claim 5.
In the control device, when the load of the gas turbine is from a no-load condition to a low-load condition, an equivalence ratio of a region from the burner side end portion to a position corresponding to the bypass air hole in the liner is 1.0. A gas turbine combustor that controls a valve opening degree of the bypass valve. The gas turbine combustor according to claim 5 or 7,
In the control device, when the load of the gas turbine is from a high load condition to a rated load condition, an equivalence ratio of a region from the burner side end portion to a position corresponding to the bypass air hole in the liner is 1.5 or more and 3.0. The gas turbine combustor, wherein the opening degree of the bypass valve is controlled so as to satisfy the following conditions. The gas turbine combustor of claim 5.
A temperature detector for detecting a temperature of an area surrounded by the bypass air receiving portion in the liner;
The said control apparatus controls the valve opening degree of the said bypass valve based on the detection signal of the said temperature detector, and the load condition of a gas turbine. The gas turbine combustor characterized by the above-mentioned. The gas turbine combustor according to claim 9,
When the detection signal of the temperature detector exceeds a predetermined set value and the load of the gas turbine is less than 50%, the control device outputs a command to reduce the valve opening to the bypass valve. A gas turbine combustor that outputs a command to increase the valve opening to the bypass valve when the load of the turbine is 50% or more. A compressor that compresses air to generate high-pressure compressed air;
A combustor that generates combustion gas by mixing and burning compressed air and fuel introduced from the compressor;
A turbine that obtains a shaft driving force by the energy of the combustion gas generated in the combustor,
The combustor includes a liner forming a combustion chamber therein;
An outer cylinder containing the liner;
A bypass air receiving portion installed in the outer cylinder so as to surround a predetermined region including an end portion on the upstream side of the combustion gas in the liner, and forming an annular space together with the liner;
A bypass pipe connected at one end to the bypass air receiving portion, and bypassing a part of the compressed air from the compressor as bypass air to the bypass air receiving portion;
A bypass valve that is installed in the bypass pipe and is capable of adjusting a flow rate of bypass air flowing through the bypass pipe;
The liner has a bypass air hole that communicates the space in the bypass air receiving portion and the combustion chamber at a predetermined position in a region surrounded by the bypass air receiving portion. A gas turbine operation method comprising a gas turbine combustor having a liner forming a combustion chamber therein and a burner provided at one end of the liner in the axial direction,
Detects gas turbine load conditions,
The bypass air receiving portion of the liner is surrounded by the bypass air receiving portion that is installed so as to surround a predetermined region including the burner side end portion of the liner and forms an annular space together with the liner. A gas turbine operation characterized by adjusting a flow rate of bypass air, which is a part of compressed air from a compressor flowing into the combustion chamber from a predetermined position in a region, in accordance with a detected load condition of the gas turbine. Method. A method for operating a gas turbine according to claim 12,
When the detected load condition of the gas turbine is either a no-load condition or a low-load condition, the equivalence ratio of the region from the burner side end in the liner to the position corresponding to the bypass air hole is 1.0. The gas turbine operating method is characterized by adjusting the flow rate of the bypass air so that A method for operating a gas turbine according to claim 12 or 13,
When the detected load condition of the gas turbine is either a high load condition or a rated load condition, the equivalence ratio of the region from the burner side end in the liner to the position corresponding to the bypass air hole is 1.5. The gas turbine operating method is characterized in that the flow rate of the bypass air is adjusted to be 3.0 or less. A method for operating a gas turbine according to claim 12,
Further detecting the temperature of the area surrounded by the bypass air receiving portion in the liner;
Further determine whether or not the detected temperature exceeds a preset value,
When it is determined that the detected temperature has exceeded the set value and the detected load of the gas turbine is less than 50%, the flow rate of the bypass air is decreased,
A method of operating a gas turbine, comprising: determining that the detected temperature exceeds the set value and increasing the flow rate of the bypass air when the detected load of the gas turbine is 50% or more.

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