JP5483625B2 - Gas turbine system - Google Patents

Description

  The present invention relates to a gas turbine having intake spray and an operating method thereof.

  In the operation of a gas turbine in summer or the like, the output of the gas turbine decreases due to a decrease in intake air density when the atmospheric temperature is high. In response to this decrease in output, for example, in a gas turbine compressor described in Japanese Patent Application Laid-Open No. 9-236024 of Patent Document 1, the intake density is increased by spraying droplets of water or the like on the intake air of the compressor. There is a method of improving the gas turbine output by the effect of the intake air cooling. Further, when the droplet spray amount is increased and the droplet is introduced into the compressor, the efficiency of the gas turbine can be improved by reducing the compression power due to the effect of the intermediate cooling. In such a gas turbine operation that introduces droplets into the compressor, it is necessary to remove all the droplets inside the compressor when the gas turbine is stopped in order to ensure the reliability of the gas turbine. Necessary. However, there is no description of a purge operation for removing droplets when the gas turbine that sprays droplets on the intake air of the compressor is stopped.

  Further, in the blade cleaning of the gas turbine compressor, for example, in Patent Document 2, the purge operation after cleaning the compressor blade, the amount of detergent or contaminants in the cleaning water is measured from the drain of the compressor outlet to clean the blade. A method for detecting the completion of is described. In a gas turbine in which droplets are introduced into the compressor for the purpose of intermediate cooling effect, the compression power can be reduced by evaporating the droplets in the upstream stage of the compressor. In addition, if droplets are present up to the compressor outlet, droplets may also enter the air supplied to the combustor and the turbine blade cooling air, which may increase thermal stress, reducing the reliability of the gas turbine. Let Therefore, since it is necessary to completely evaporate the droplets at the outlet of the compressor, it is not necessary to detect the droplets at the outlet of the compressor.

Japanese Patent Laid-Open No. 9-236024 JP 2009-115079 A

  When a spray nozzle is placed in the intake duct to spray a large amount of droplets on the intake air of the compressor, some of the sprayed droplets are vaporized in the intake duct until the intake air is saturated, and the latent heat of evaporation As a result, the temperature of the gas entering the compressor is lower than the outside air temperature. And the gas containing the droplet which could not be vaporized is conveyed inside a compressor, and is vaporized, compressing inside a compressor. The vaporization of the droplets inside the compressor reduces the compression power because the compression characteristic approaches that of isothermal compression.

  Here, in the gas turbine that supplies droplets to the inside of the compressor, problems due to the droplets remaining inside the compressor when the gas turbine is stopped will be described.

  Among the droplets introduced into the compressor during the operation of the gas turbine, fine droplets riding on the airflow evaporate while passing between the moving blades and the stationary blades of the compressor. However, a droplet that has a large droplet diameter and cannot ride on an air current collides with the moving vane and the inner wall of the side wall. Further, the liquid droplets colliding with the moving blades are blown off to the outer peripheral side by the centrifugal force rotating the moving blades to form a liquid film on the inner wall of the casing. When the gas turbine is stopped in such a state, the liquid film accumulates under the casing due to gravity. Further, since the compressor has a tapered shape from the inlet, there is a high possibility that droplets will accumulate in the plenum located on the compressor inlet side.

  When droplets are sprayed in the intake duct of a gas turbine, the droplets that have a large droplet size and cannot ride on the air current collide with the intake duct wall to form a liquid film and accumulate in the plenum on the compressor inlet side. . Thus, in a gas turbine that sprays droplets on the intake air of the compressor, when the gas turbine is stopped without completely purging the droplets, the droplets are accumulated on the inlet side of the compressor. When the gas turbine is started from the state in which these droplets have accumulated, droplets with a large particle diameter fly from the accumulated droplets as secondary droplets to the inside of the compressor. There is a possibility of acceleration.

  In order to avoid a flow unsteady phenomenon, which is called swirling stall when the gas turbine is started, variable stator vanes are installed in the upstream stage of the axial compressor. Each variable stationary blade is attached to the casing, and in a compressor that sprays liquid droplets, there is a possibility that the liquid droplets are mixed into the mating surface between the mounting portion of the variable stationary blade and the casing. If droplets are present in the casing and variable stator blade attachment after the gas turbine is stopped, there is a possibility of corrosion such as rust in the operating part of the variable stator blade. This erosion affects the angle of the variable blades and thus reduces the reliability of the gas turbine. Furthermore, since the angle deviation of the inlet guide vanes greatly affects the suction flow rate of the gas turbine, there is a concern about the influence on the output of the gas turbine.

  Furthermore, in an operation in which the gas turbine is stopped at night, the gas turbine is stopped in a state where droplets are accumulated in the plenum on the compressor inlet side. Part of the droplet may solidify and icing may occur. When the gas turbine is started in a state where the icing is generated, a part of the ice block may fly into the compressor, and may collide with the compressor cascade to damage the cascade.

  As described above, in the gas turbine that sprays a large amount of droplets at the inlet of the compressor, the operation of purging the droplets when the gas turbine is stopped is important from the viewpoint of the reliability of the gas turbine.

  An object of the present invention is to suppress the remaining of the drain inside the compressor and ensure the reliability of the gas turbine.

In order to achieve the above object, the present invention includes a compressor that compresses air, a combustor that generates combustion gas by mixing and burning high-pressure air and fuel compressed by the compressor, and the combustor. A turbine that is rotated by the generated combustion gas, and a gas turbine that includes means for supplying a liquid to the compressor, wherein the compressor includes droplet residual detection means, and is provided on the inlet side of the compressor. It is provided with an intake plenum provided and a drain system for discharging the drain from the bottom surface of the intake plenum, and the droplet residual detection means is a measuring means for measuring the drain amount of the drain system .

  ADVANTAGE OF THE INVENTION According to this invention, the residue of the drain inside a compressor can be suppressed and the reliability of a gas turbine can be ensured.

The gas turbine system block diagram which is one of the embodiment of this invention. The meridian plane sectional view of the axial flow compressor of the embodiment of the present invention. AA sectional drawing in the meridional sectional view of the axial flow compressor of FIG. The gas turbine system block diagram which is one of the embodiment of this invention. The gas turbine system block diagram which is one of the embodiment of this invention. The gas turbine system block diagram which is one of the embodiment of this invention.

  FIG. 1 shows an outline of an overall configuration diagram of a gas turbine system for intake spray. Hereinafter, a configuration example of a gas turbine system for intake spray will be described with reference to FIG.

  The gas turbine system includes a compressor 1 that compresses air to generate high-pressure air, a combustor 2 that mixes and burns compressed air and fuel, and a turbine 3 that is rotationally driven by high-temperature combustion gas. The compressor and the turbine are connected to the generator 4 via a rotating shaft.

  Next, the flow of the working fluid will be described. Air 11 as a working fluid flows into the compressor 1 and flows into the combustor 2 as high-pressure air 12 while being compressed by the compressor. High-pressure air 12 and fuel 13 are mixed and burned in the combustor 2, and high-temperature combustion gas 14 is generated. The combustion gas is discharged to the outside as the exhaust gas 15 after rotating the turbine 3. The generator 4 is driven by the rotational power of the turbine transmitted through the rotary shaft 5 that communicates the compressor and the turbine.

  In compressors with a constant volume flow rate and constant rotation generally used in gas turbine systems, when the intake air temperature rises, such as in summer, the air density decreases and the mass flow rate of the intake air decreases. The fuel flow rate in the combustor must also be reduced. That is, there is a problem that the output of the gas turbine decreases as the intake air temperature of the compressor increases.

  In order to solve this problem, there is a method of improving the gas turbine output by supplying a liquid such as water to the compressor by an intake cooling effect. Specifically, water droplets are sprayed on the intake air of the compressor. As a method for cooling the intake air, there is a method in which a media type intake air cooler is installed in the intake air duct and the intake air is lowered by passing the intake air through the intake air cooler. On the other hand, as shown in FIG. 1, a droplet spray nozzle 32 is disposed in the intake duct 31 to spray fine droplets in the intake air and evaporate them in the air stream, thereby adjusting the intake air temperature by the latent heat of evaporation of the droplets. There is also a way to reduce it. In the case of such a method of spraying droplets, in addition to the intake air cooling effect in which the droplets evaporate in the intake duct when the amount of droplets is increased, the droplets are also supplied to the inside of the compressor. An intermediate cooling effect can be obtained by vaporization. This effect can contribute to higher efficiency of the gas turbine by improving the output of the gas turbine and reducing the compression power.

  Next, the start and stop timing of droplet spraying will be described. The droplet spraying starts when the gas turbine is started and the rated load is reached. When droplets are introduced to the inside of the axial flow compressor, the blade row load is reduced on the upstream side of the compressor due to a temperature drop due to vaporization of the droplets, and conversely, the blade row load is increased on the downstream side. In a partial load operation of a general gas turbine, since the blade cascade load on the downstream side of the compressor is larger than that on the upstream side, spraying droplets at the time of partial load further increases the blade cascade load on the downstream side. There are concerns about reducing the reliability of the column. Accordingly, the spraying of droplets is started during stable operation when the gas turbine reaches the rated load. Similarly, the spraying of droplets is stopped at the rated load operation of the gas turbine, and the spraying is stopped before the gas turbine is stopped.

  When the gas turbine is stopped immediately after the spraying of the droplets is stopped, there is a possibility that the droplets that could not be evaporated remain in the intake duct of the compressor or the upstream side of the compressor. In addition, since the working fluid flowing inside the compressor contains a large amount of moisture, when the gas turbine is stopped, the air temperature inside the compressor suddenly decreases and the droplets condense, and the condensed droplets fall on the inner wall of the casing. It is thought that it adheres. A problem caused by the droplet remaining inside the compressor will be described.

  Among the droplets introduced into the compressor during the operation of the gas turbine, fine droplets riding on the airflow evaporate while passing between the moving blades and the stationary blades of the compressor. However, a droplet that has a large droplet diameter and cannot ride on an air current collides with the moving vane and the inner wall of the side wall. Further, the liquid droplets colliding with the moving blades are blown off to the outer peripheral side by the centrifugal force rotating the moving blades to form a liquid film on the inner wall of the casing. When the gas turbine is stopped in such a state, the liquid film becomes a drain and accumulates under the casing by gravity. When the gas turbine is started with the accumulated droplets remaining, the resistance against the rotating direction of the blades increases due to the contact between the compressor blades rotating at high speed and the droplets, causing a decrease in output. When a large amount of liquid droplets remain, a discontinuous impact is applied to the compressor blade, which may damage the compressor blade.

  Further, since the compressor has a tapered shape from the inlet, droplets remaining inside the compressor may flow and accumulate in the intake plenum 33 located on the compressor inlet side. Further, when the droplets are sprayed in the intake duct 31 of the gas turbine, the droplets having a large droplet size that cannot be carried on the airflow collide with the intake duct wall to form a liquid film and drop into the plenum on the compressor inlet side. Accumulates. Thus, in a gas turbine that sprays droplets on the intake air of the compressor, when the gas turbine is stopped without completely purging the droplets, the droplets are accumulated on the inlet side of the compressor. When the gas turbine is started from the state in which these droplets have accumulated, the droplets with large particle diameters, which are secondary droplets, fly into the compressor, so it is possible to accelerate erosion by colliding with the first stage rotor blades. There is sex.

  In order to avoid a flow unsteady phenomenon, which is called swirling stall when the gas turbine is started, variable stator vanes are installed in the upstream stage of the axial compressor. Each variable stationary blade is attached to the casing, and in a compressor that sprays liquid droplets, there is a possibility that the liquid droplets are mixed into the mating surface between the mounting portion of the variable stationary blade and the casing. If droplets are present in the casing and the variable stator blade attachment after the gas turbine is stopped, there is a concern that corrosion such as rust occurs in the variable stator blade operating part. Since this corrosion affects the angle of the variable stationary blade, it may affect the output of the gas turbine in addition to reducing the reliability of the gas turbine.

  Furthermore, when the gas turbine is stopped at night, when the gas turbine is stopped with droplets accumulated in the plenum on the compressor inlet side, the outside air temperature is reduced and accumulated during the night. There is a possibility that a part of the solidified and icing (freezing) may occur. When the gas turbine is started in a state where the icing is generated, a part of the ice block jumps into the compressor, so that there is a high possibility of colliding with the compressor cascade and damaging the cascade.

  In order to avoid such a problem, it is necessary to perform an operation of purging droplets inside the intake duct and the compressor when the gas turbine is stopped. In general, the purge operation of the gas turbine is performed in a low rotation speed region when the gas turbine is started, and is not performed when the gas turbine is stopped (including before and after the operation is stopped). This type of purge operation is carried out for a few minutes for the purpose of exhausting fuel (such as LNG gas) remaining in the combustor downstream of the turbine and exhausting it outside the system. This purge operation is performed for a certain period of time, and does not detect the completion of the purge by measuring the state quantity of the working fluid.

  On the other hand, the purge operation which is an embodiment of the present invention described later is performed immediately before the gas turbine is stopped, and the purge operation is completed by detecting droplets remaining in the intake duct and the compressor.

  Next, a method for detecting droplets remaining in the intake duct and the compressor will be described with reference to FIG.

  A first drain tank 42 is installed from an intake plenum 33 provided on the inlet side of the compressor via a pipe 41. The first drain tank 42 is provided with a drain amount measuring device 42a which is a measuring means for measuring the drain amount. This drain amount measuring device 42a serves as a droplet remaining detection means. That is, it can be said that if the change in the drain amount stops, it is detected that no drain (droplet) remains in the compressor. A U-seal 41 is provided between the intake plenum and the drain tank 42 for the purpose of suppressing a back flow due to a pressure difference between the intake plenum and the drain tank during gas turbine operation. The droplets remaining in the intake portion of the compressor 1 are discharged to the drain tank via the drain pipe. The purge is completed when the amount of drain generated in the intake plenum is exhausted.

  Further, a second drain tank 44 for drain detection is installed in a part of the bleed piping 43 provided in the casing on the upstream stage side of the compressor. The second drain tank 44 is provided with a drain amount measuring device (not shown). The air extracted from the upstream stage of the compressor is used as seal air for the bearing during operation of the gas turbine. Since the pressure can be secured above the atmospheric pressure during the operation of the gas turbine, it is not necessary to install a U seal as shown in the drain evacuation method in the intake plenum between the extraction pipe and the drain tank. Since the drain amount measuring device provided in the drain tank 44 can measure the drain amount in the extraction stage and detect the amount of liquid droplets remaining in the compressor, a highly reliable purge operation is possible. Further, a temperature measuring mechanism 45 capable of measuring the atmospheric temperature inside the compressor is disposed between the stages of the moving and stationary blades upstream of the compressor. This temperature measuring means is provided on the inner surface of the compressor casing at the lowermost portion in the circumferential direction at a certain axial position, and can effectively detect the presence of droplets accumulated in the lower portion due to gravity.

  In the temperature measurement, the temperature deviation after the intake spray is stopped is measured, and after confirming that the deviation is below a certain limit value, the operation of stopping the gas turbine is started. Further, the temperature can be measured at a plurality of points in the circumferential direction at the same axial position where the compressor is located, and the circumferential deviation can be evaluated. When droplets remain inside the annular casing, it is considered that the temperature deviation increases at the upper and lower portions of the casing. The temperature measurement between the stages of the compressor moving blades and the stationary blades is possible in the axial direction and the circumferential direction position even in a space having a variable stationary blade mechanism located upstream of the compressor. It is possible to detect the purge of the drain remaining in the chamber, and to ensure the soundness of the variable stationary blade mechanism.

  In the purge operation of a gas turbine that sprays droplets on the intake air of the compressor, the remaining droplets inside the compressor can be detected by measuring the drain temperature and the ambient temperature inside the compressor. Interference between the moving blade and the remaining droplets can be suppressed, and the risk of damage to the moving blade can be reduced. Further, since solidification of residual droplets due to a decrease in atmospheric temperature can be suppressed, the risk of damaging the compressor blades due to icing can be reduced, and reliability can be improved. Furthermore, since corrosion of the drive parts due to the droplets remaining in the variable stationary blade mechanism of the compressor can be suppressed, gas turbine operation control and long-term reliability can be ensured.

  Next, a method for purging remaining droplets will be described. During the purge operation of the gas turbine, it is necessary to operate at a certain rotation speed. At the partial rotational speed of the gas turbine, the resonance at the compressor blade and the turbine blade and resonance with the shaft vibration may cause damage to the rotating parts. Therefore, operation at the rated rotational speed is safe and preferable. Further, since the suction flow rate can be increased and the time for purging the remaining droplets can be shortened as the rotational speed is higher, it is effective to operate at the rated rotational speed. Since the gas turbine load has the highest combustion temperature at the rated load and the pressure ratio in the compressor can be increased, the purge operation of the drain accumulated on the upstream side of the compressor should be performed at the rated load. However, the purge time can be shortened compared to the partial load. On the other hand, if purged at the rated load, a large amount of fuel is consumed, so the economy becomes a disadvantage. When purge operation is performed at 100% rpm and no load, the discharge temperature of the compressor can be ensured to be 200 ° C or higher, so droplets remaining in the compressor are completely evaporated inside the compressor and supplied to the combustor. Therefore, the purge operation can be sufficiently performed.

  A detailed drain measurement method will be described using the schematic diagram of the meridional section of the compressor in FIG. The axial compressor 1 includes a rotating rotor 52 to which a plurality of moving blades 51 are attached and a casing 54 to which a plurality of stationary blade rows 53 are attached. An annular flow path is formed by the rotor 52 and the casing 54. Yes. The moving blades 51 and the stationary blade rows 53 are alternately arranged in the axial direction, and one moving blade row and the stationary blade row form a stage. An inlet guide vane (IGV) 55 that can adjust the gas turbine load by controlling the suction flow rate is provided on the upstream side of the first stage moving blade row. Further, the front stator blade row is provided with a variable stator blade mechanism 56 in order to suppress turning stall at the time of starting the gas turbine. In FIG. 2, only the first stage stationary blade row is provided with the variable mechanism, but there may be a plurality of variable stationary blade rows.

  The air 11 flowing in from an intake duct (not shown) is turned 90 degrees by an intake plenum 33 located on the upstream side of the compressor, and is supplied into the compressor. Droplets such as water are ejected from the spray nozzle 32 disposed inside the intake duct, and the fine droplets evaporate in the airflow, and the intake air is simultaneously reduced with the temperature of the gas flowing into the compressor due to the latent heat of evaporation. Increase the density. Among the fine droplets conveyed along with the air flow, the droplets that could not be vaporized to saturation up to the intake plenum flow into the compressor as droplets. Inside the compressor, the droplets evaporate while passing between the moving blade rows and between the stationary blade rows, thereby lowering the temperature of the working fluid during compression. Since the compression characteristic approaches the isothermal compression by the intermediate cooling effect, the power of the compressor is reduced. The droplets introduced into the compressor are completely evaporated before the compressor is discharged.

  Next, the cause of drain generation due to intake spray will be described. When spraying about 1% or more of droplets in the suction duct in the intake duct, it is necessary to arrange about 100 to 200 spray nozzles in the duct. Therefore, there is a possibility that the nozzle interval is dense, and the droplets collide immediately after ejecting the droplets, the particle size becomes large, and there is a possibility that it becomes a drain without getting on the air current. Further, when the spray nozzle is disposed in the vicinity of the wall surface of the duct, it immediately collides with the wall surface immediately after jetting to form a liquid film and remains as a drain. Furthermore, since the flow is turned 90 degrees from the intake plenum to the inside of the compressor, there is an increased possibility that a liquid droplet that cannot get on the air flow having a relatively large particle diameter will collide with the wall surface and become a liquid film. Even inside the compressor, droplets collide with the inlet guide vane 55 and the first stage moving blade 51 rotating at high speed to form a liquid film on the blade surface. The liquid droplet colliding with the moving blade is accumulated as a drain on the inner wall of the annular casing 54 by centrifugal force. Further, when the injection is stopped, a droplet having a large particle diameter is generated from the spray nozzle 32 due to liquid dripping.

  In this way, as the amount of droplets sprayed in the intake air increases, the amount of drain inside the intake duct and compressor increases, and after the gas turbine stops, the drain accumulates on the bottom surface of the intake plenum and the lower side of the annular casing due to gravity. I will do it. Further, the inner wall of the annular casing of the compressor has a tapered shape, and the drain accumulated on the inner wall of the casing may be conveyed to the intake plenum side. When the intake spray amount becomes 2% or more with respect to the suction flow rate ratio, about 20 to 30% of the sprayed amount may be discharged as a drain in the intake duct.

  A specific method for detecting the generated drain will be described. In order to discharge the drain accumulated in the intake plenum 33, a drain tank 42 is installed from the bottom surface 61 of the intake plenum 33 through a pipe 41 constituting the drain system. During the purge operation, the pressure inside the intake plenum may become a negative pressure, and a U seal 41a is provided in the pipe in order to suppress the back flow of the drain due to the difference in internal pressure with the drain tank.

  Furthermore, the compressor 1 has an extraction system. Specifically, a bleed chamber 57 is provided in an annular shape on the casing of the compressor, and a drain tank 44 is provided in a part of the bleed pipe 43 installed at the lowest position of the bleed chamber 57, and the bleed chamber of the compressor is provided. The accumulated drain can be discharged out of the system. In addition, a temperature measuring mechanism 45 that measures the ambient temperature of the working fluid is provided in the vicinity of the inner wall of the casing between the moving and stationary blade rows located on the upstream side of the compressor. Since the variable stator vane mechanism 56 is arranged over the entire circumferential region on the casing outer wall on the upstream side of the compressor, there is no space for discharging the accumulated drain using the piping outside the system. Therefore, as in this embodiment, the presence or absence of a drain can be detected by measuring the temperature in the vicinity of the inner wall of the casing of the variable stationary blade. This temperature measurement position is preferably measured at the lowest point of the inner wall of the annular casing and is measured downstream of the stationary blade and upstream of the moving blade.

  FIG. 3 shows a cross-sectional view of the AA cross section of FIG. 2 as seen from the upstream side of the compressor. By measuring a plurality of temperatures in addition to the circumferential lowest point 45 at the same axial position, the circumferential deviation can be monitored and the drain can be detected with high accuracy. This temperature measurement has lower detection accuracy than the measurement using the drain tank, but it is possible to measure even in a narrow space where the drain discharge pipe near the variable stationary blade cannot be installed, and the equipment can be simplified. So there is a merit of cost reduction.

  The purge operation method of the high humidity gas turbine system that is an embodiment of the present invention will be described with reference to FIG. FIG. 4 is a configuration diagram of a high-humidity-utilizing gas turbine system. The difference from the gas turbine system of FIG. 1 is that a humidifier 71 that adds moisture to the discharge air of the compressor and the exhaust heat of the gas turbine are recovered. That is, the regenerative heat exchanger 72 is arranged.

  The high humidity gas turbine is composed of a compressor 1, a combustor 2, a turbine 3, a humidifier 71, and a regenerative heat exchanger 72. The intake spray nozzle sprays water into the atmosphere to generate moisture air. The moisture air generated by the intake air spray is compressed by the compressor, and the compressed air generated by the compressor is once extracted 16 at the extraction holes provided at the gas path outlet. The high-pressure air extracted from the compressor outlet is humidified by a humidifier. The humid air 17 humidified by the humidifier is supplied to a regenerative heat exchanger that is overheated by exhaust gas from the turbine. Then, in the regenerative heat exchanger, the moisture air supplied from the humidifier is superheated, and the moisture air 18 is generated and supplied to the combustor 2. The humid air supplied to the combustor is mixed and burned with fuel in the combustor. And the produced | generated combustion gas 14 is introduce | transduced into a turbine and rotationally drives a turbine. The exhaust gas 15 discharged from the turbine is recovered by the regeneration heat exchanger and discharged as exhaust gas.

  In the regenerative heat exchanger, the heat energy of the exhaust gas can be recovered in the combustion air, so that the fuel flow rate in the combustor is reduced and the efficiency of the gas turbine cycle is improved. Further, the output of the high-humidity gas turbine is increased by adding the moisture in the humidifier and increasing the working fluid. Furthermore, the heat recovery amount in the regenerative heat exchanger increases and the efficiency of the high-humidity gas turbine is improved due to the effect of decreasing the temperature of the working fluid and the effect of increasing the flow rate due to the addition of moisture.

  The purge operation in the high humidity gas turbine system will be described. In the stop operation of the high-humidity gas turbine system, the intake spray to the compressor is stopped first from the rated load operation. Next, the water supply supplied to the humidifier is stopped. The operation is maintained until the output of the gas turbine is stabilized after the water supply to the humidifier is stopped. During this operation, the compressor is equivalent to a purge operation of the remaining droplets, and therefore it is not necessary to provide a special purge operation as in the case of FIG. In this embodiment, this operation is also regarded as a purge operation. If the purge of the drain is not completed until the output of the gas turbine is stabilized after the atmospheric temperature condition and a large amount of drain are generated and the water supply of the humidifier is stopped, the gas turbine is continuously operated, As described above, it is possible to perform the purge operation in a no-load state. When the purge operation is completed, the fuel valve supplied to the combustor is shut off and the gas turbine is stopped.

  A method for discharging the drain remaining in the intake plenum according to the embodiment of the present invention will be described with reference to FIG. FIG. 5 is a configuration diagram of a gas turbine system according to an embodiment of the present invention. The difference from FIG. 1 is that a vacuum pump 81 is provided in a drain tank 42 for storing a drain discharged from the intake plenum 33. In the case of the U seal as shown in FIG. 1, the back flow of the drain into the intake plenum is suppressed by providing the height (head) of the U seal. However, the state quantity in the intake plenum of the gas turbine changes depending on the atmospheric temperature condition and the intake duct shape. Moreover, since the amount of intake spray varies depending on each plant, the amount of generated drain also varies. Therefore, the U seal shape needs to be designed individually for each plant, and has a design period and a production period. On the other hand, by setting the inside of the drain tank to a negative pressure using a vacuum pump as in the present invention, it becomes possible to maintain the pressure difference between the intake plenum and the drain tank, and to suppress the backflow of the remaining drain. it can. Thereby, the reliability of gas turbine operation can be secured.

  The purge operation which is an embodiment of the present invention will be described with reference to FIG. FIG. 6 is a block diagram of a gas turbine system according to an embodiment of the present invention. The difference from FIG. 1 is that an extraction system for introducing a part of high-temperature and high-pressure working air of a compressor into an intake duct or an intake plenum. 82 is provided. By supplying a part of high-temperature and high-pressure working air to the intake side, the compressor inlet temperature rises and the saturated water vapor amount can be increased. Therefore, it is possible to effectively evaporate the remaining droplets, and the time required for the purge operation can be shortened.

  Finally, the control system in the embodiment of the present invention will be described with reference to FIG. As described above, in this embodiment, the purge operation is performed when the gas turbine is stopped (immediately before the stop) in order to suppress the residual liquid droplets in the intake duct and the compressor. In this purge operation, residual droplets are detected based on measurement signals from various parts of the gas turbine system, and the purge operation is stopped when it is determined that there are no residual droplets. In the present embodiment, in particular, the controller 101 for controlling the purge operation is provided based on the measurement result of the drain amount measuring device 42a which is a droplet remaining detection means.

  The dotted line in FIG. 1 shows a control signal. The compressor 91 is disposed in the upstream stage of the compressor, and the drain amount signal 91 of the compressor intake plenum 33 and the drain amount signal 92 from the compressor bleed pipe. A signal 93 from the internal temperature measurement is introduced into the controller 101. For example, the drain amount is measured by a drain amount measuring device 42 a provided in the drain tank 42.

  In this embodiment, the intake plenum drain measurement (signal 91) is essential. This is because the intake plenum has a larger amount of drain than in other locations, and if left, the influence on the reliability of the gas turbine is great. On the other hand, drain measurement (signal 92) in the extraction stage is not always necessary. During the purge operation, in the extraction stage, droplets are almost evaporated, and even if the drain remains, the casing inner wall temperature and the pipe temperature are 100 ° C. or more, and it is considered that the drain evaporates instantly when the drain collides with the wall surface. Because. When it is determined by the signal introduced to the controller 101 that the purge of residual droplets has been completed, the gas turbine starts a stop operation, and an output signal 94 is sent to the fuel system valve 102 connected to the gas turbine combustor. The gas turbine is stopped by shutting off the fuel transmitted and supplied to the combustor.

  In this embodiment, an example of performing the purge operation at the time of stoppage has been introduced. Essentially, however, the liquid remaining in the compressor 1 and the intake duct 31 is reduced by performing the purge operation after the liquid supply to the compressor is finished. Can be suppressed. In the gas turbine of this embodiment, during the rated load operation, the spraying of droplets to the compressor is first stopped and the purge operation is started, and the purge operation is performed when it is determined by the drain amount measuring device that there are no remaining droplets. Is stopped.

  In addition, although control of the purge operation of the present embodiment has been described with reference to FIG. 1, similar control is also possible in the gas turbine systems of FIGS. 4 to 6. Further, in addition to the gas turbine axial flow compressor using the intake spray, a similar system can be applied to an industrial axial flow compressor.

  The gas turbine system according to the embodiment of the present invention described above includes a compressor 1 that compresses air, and a combustor 2 that generates combustion gas by mixing and burning high-pressure air compressed by the compressor 1 and fuel. And a turbine 3 rotated by combustion gas generated in the combustor 2, and a gas turbine including a spray nozzle 32 that is a means for supplying a liquid to the compressor 1. A drain amount measuring device 42a installed in the drain tank 42 serving as detection means is provided. Therefore, when performing the purge operation when the gas turbine is stopped, the purge operation can be continued until it can be confirmed that there are no remaining droplets. Therefore, the residual drain in the compressor 1 is suppressed, and the reliability of the gas turbine is improved. Can be secured. Further, it is possible to suppress the purge operation from being continued for a longer time than necessary, and it is also possible to enjoy the merit that highly economical operation is possible.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Combustor 3 Turbine 4 Generator 5 Rotating shaft 31 Intake duct 32 Spray nozzle 33 Intake plenum 41, 43 Piping 41a U seal 42, 44 Drain tank 42a Drain amount measuring device 45, 46 Temperature measuring mechanism 51 Moving blade 52 Rotor 53 Stator blade row 54 Casing 55 Inlet guide vane 56 Variable stator blade mechanism 57 Extraction chamber 61 Bottom surface of intake plenum 71 Humidifier 72 Regenerative heat exchanger 81 Vacuum pump 82 Extraction system 91, 92, 93, 94 Signal 101 Controller 102 valve

Claims (11)

A compressor that compresses air; a combustor that generates combustion gas by mixing and burning high-pressure air compressed by the compressor and fuel; and a turbine that is rotated by the combustion gas generated by the combustor. A gas turbine comprising means for supplying a liquid to the compressor;
The compressor includes a droplet remaining detection means,
An intake plenum provided on the inlet side of the compressor, and a drain system for discharging the drain from the bottom surface of the intake plenum,
The gas turbine according to claim 1, wherein the remaining droplet detection means is a measuring means for measuring a drain amount of the drain system. 2. The gas turbine according to claim 1 , wherein the drain system has a drain tank, and the measuring means is a drain amount measuring device for the drain tank. The gas turbine according to claim 1 or 2 ,
The gas turbine according to claim 1, wherein the drain system has a U seal. The gas turbine according to claim 2 , wherein
A gas turbine comprising a vacuum pump for making the inside of the drain tank have a negative pressure. In the gas turbine in any one of Claims 1-4 ,
A gas turbine comprising temperature measuring means at a circumferential lowermost portion of a casing of the compressor. The gas turbine of claim 5 .
A gas turbine comprising a plurality of temperature measuring means at the same axial position of the compressor. In the gas turbine in any one of Claims 1-6 ,
The compressor has an extraction system, and the extraction system includes a drain tank. In any of the gas turbine according to claim 1-7,
A gas turbine, wherein the liquid supplied to the compressor is water. The gas turbine according to any one of claims 1 to 8 ,
A gas turbine comprising: a controller that receives a signal from the droplet remaining detection means and transmits a signal to a valve of a fuel system connected to the combustor. A compressor that compresses air; a combustor that generates combustion gas by mixing and burning high-pressure air compressed by the compressor and fuel; and a turbine that is rotated by the combustion gas generated by the combustor. A gas turbine operating method comprising means for supplying a liquid to the compressor,
A method of operating a gas turbine, wherein the compressor includes a droplet residual detection means, and a purge operation is controlled based on a measurement result of the droplet residual detection means. The method of operating a gas turbine according to claim 10 ,
An operation method of a gas turbine, comprising: stopping a liquid supply to the compressor, starting a purge operation, and stopping the purge operation based on a measurement result by the droplet remaining detection means.