Cooling device control system, cooling device control method, and cooling device control program

Abstract

The present application relates to a cooling device control system for controlling a cooling device for cooling an upper housing when a turbine having a turbine cabin comprising the upper housing and a lower housing is stopped. The cooling device control system comprises a first temperature sensor and a second temperature sensor installed in the upper housing and / or the lower housing. The cooling device control system generates a first control signal on the basis of detection results of the first temperature sensor and the second temperature sensor, and generates a second control signal on the basis of previously prepared control information. If there are no abnormalities in the first temperature sensor and the second temperature sensor, the cooling device is controlled by using the first control signal as a control signal; and if there is an abnormality in the first temperature sensor and / or the second temperature sensor, the cooling device is controlled by using the second control signal as a control signal.

Description

Cooling device control system, cooling device control method, and cooling device control program

[0001] This application claims priority to Japanese Patent Application No. 2024-128148, filed with the Japan Patent Office on August 2, 2024, the contents of which are incorporated herein by reference.

[0002] Turbines that can be driven by a working fluid are known as one type of power generation source. This type of turbine is used, for example, in gas turbines that can drive the turbine using combustion gas generated by burning fuel as a working fluid, and steam turbines that can drive the turbine using steam generated by burning combustion gas as a working fluid. The turbine has a rotating shaft disposed within a turbine casing formed by a housing, and the rotating shaft is rotated by receiving a working fluid guided between the rotating shaft and the housing. In some of these turbines, the housing that constitutes the turbine casing includes an upper housing and a lower housing that are combined by bolting their respective flanges together. Heat insulating materials are provided on the outer circumferential surfaces of the lower housing and the upper housing to suppress internal heat dissipation during operation.

[0003] In turbines with this type of structure, when operation is stopped, natural convection causes the lower part of the housing to cool faster than the upper part, resulting in a temperature difference between the upper and lower housings, which can cause the housing to warp upward (a phenomenon known as cat-back). Previously, the clearance between the rotating shaft and the housing was relatively large, so housing deformation due to cat-back was not a problem. However, with recent improvements in turbine performance, clearances have tended to shrink. Therefore, housing deformation that occurs when the turbine is stopped can cause the rotating shaft to come into contact with seals, such as labyrinth seals, installed on the housing, which can result in problems when the turbine is restarted.

[0004] To solve this problem, Patent Document 1 proposes supplying cooling air to the upper housing when the unit is not operating, thereby reducing the temperature difference between the upper and lower housings and suppressing housing deformation due to the cat-back phenomenon. In particular, the supply of cooling air to the upper housing is controlled based on the temperature difference between the upper and lower housings, which is determined based on the detection values ​​of temperature sensors such as thermocouples disposed in the upper and lower housings.

[0005] Japanese Patent Application Laid-Open No. 2004-52567

[0006] In the above-mentioned Patent Document 1, the amount of cooling for the upper housing is controlled based on the detection values ​​of temperature sensors installed in the upper and lower housings. Therefore, if these temperature sensors malfunction or experience other abnormalities, it becomes difficult to detect the temperature properly, which may result in inappropriate cooling control for the upper housing. For example, if the amount of cooling for the upper housing is insufficient, the housing may deform due to the cat-back phenomenon as described above. On the other hand, if the amount of cooling for the upper housing is excessive, the housing may deform in the opposite direction.

[0007] At least one embodiment of the present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a cooling device control system, a cooling device control method, and a cooling device control program that can effectively suppress housing deformation even when an abnormality occurs in a temperature sensor for detecting the housing temperature.

[0008] In order to solve the above problem, at least one embodiment of the present disclosure provides a cooling device control system for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing including an upper housing and a lower housing is stopped, the cooling device control system comprising: a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; a first control signal generation unit that generates a first control signal for controlling the cooling device based on detection results of the first temperature sensor and the second temperature sensor; a second control signal generation unit that generates a second control signal for controlling the cooling device based on control information prepared in advance; a control unit that controls the cooling device based on the control signal; an abnormality determination unit that determines an abnormality in the first temperature sensor and the second temperature sensor; and a switching unit that switches the control signal to the first control signal or the second control signal when the abnormality determination unit determines that there is no abnormality in the first temperature sensor and the second temperature sensor,

[0009] In order to solve the above problem, a cooling device control method according to at least one embodiment of the present disclosure is a cooling device control method for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing including an upper housing and a lower housing is stopped, the method comprising the steps of: generating a first control signal for controlling the cooling device based on detection results of a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; generating a second control signal for controlling the cooling device based on control information prepared in advance; controlling the cooling device based on the control signal; determining whether the first temperature sensor and the second temperature sensor are abnormal; and switching the control signal between the first control signal and the second control signal; when it is determined that there is no abnormality in the first temperature sensor and the second temperature sensor, switching the control signal to the first control signal; and when it is determined that there is an abnormality in at least one of the first temperature sensor or the second temperature sensor, switching the control signal to the second control signal.

[0010] In order to solve the above problem, a cooling device control program according to at least one embodiment of the present disclosure is a cooling device control program for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing including an upper housing and a lower housing is stopped, the cooling device control program being capable of executing the following steps on a computer device: generating a first control signal for controlling the cooling device based on detection results of a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; generating a second control signal for controlling the cooling device based on control information prepared in advance; controlling the cooling device based on the control signal; determining whether the first temperature sensor and the second temperature sensor are abnormal; and switching the control signal to the first control signal or the second control signal; when it is determined that there is no abnormality in the first temperature sensor and the second temperature sensor, switching the control signal to the first control signal; and when it is determined that there is an abnormality in at least one of the first temperature sensor or the second temperature sensor, switching the control signal to the second control signal.

[0011] According to at least one embodiment of the present disclosure, a cooling device control system, a cooling device control method, and a cooling device control program can be provided that can effectively suppress housing deformation even when an abnormality occurs in a temperature sensor for detecting housing temperature.

[0012] FIG. 1 is an overall configuration diagram that schematically shows a gas turbine according to an embodiment. FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1. FIG. 3 is a perspective view showing the vicinity of the cooling cell of FIG. 2. FIG. 4 is a block configuration diagram of a control system according to an embodiment. FIG. 5 is a control flow diagram of the second control signal generating unit of FIG. 4. FIG. 6 is an example of time variation in the opening degree of the flow rate adjustment valve of FIG. 1 that is controlled based on the second control signal generated by the second control signal generating unit of FIG. 5. FIG. 7 is a flowchart that shows a cooling device control method according to an embodiment. FIG. 8 is an overall configuration diagram that schematically shows a steam turbine according to an embodiment.

[0013] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the configurations described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure.

[0014] First, a gas turbine will be described as an example configuration including a turbine equipped with a cooling device that is a control target of a cooling device control system according to at least one embodiment of the present disclosure. Fig. 1 is a schematic overall configuration diagram of a gas turbine 1 according to one embodiment, Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, and Fig. 3 is a perspective view showing the vicinity of a cooling cell 36 in Fig. 2.

[0015] As shown in Fig. 1, the gas turbine 1 includes a compressor 2, a combustor 4, and a turbine 6. The compressor 2 generates compressed air as combustion air Ac by compressing outside air (air) taken in from the outside. The combustor 4 generates combustion gas Gc by mixing and burning fuel F supplied from a fuel supply system (not shown) with the combustion air Ac generated by the compressor 2. The turbine 6 is driven by the combustion gas Gc supplied from the combustor 4. A generator 9 is connected to a rotating shaft 8 of the turbine 6, and is capable of generating electricity by being driven by power output from the turbine 6.

[0016] As shown in Fig. 2, the turbine 6 includes a housing 10 that surrounds the rotating shaft 8. The housing 10 has multiple stages of rotor blade rows (not shown) formed integrally with the rotating shaft 8 and protruding outward from the outer periphery thereof, and multiple stages of stator blade rows (not shown) formed integrally with the housing 10 and protruding outward from the inner periphery thereof and interposed between the rotor blade rows of the rotating shaft 8 that are positioned in front of and behind each other.

[0017] The housing 10 includes an upper housing 12 having a generally semicircular shape and arranged to surround the upper half of the rotary shaft 8, and a lower housing 14 having a generally semicircular shape and arranged to surround the lower half of the rotary shaft 8. The flange portion 12a of the upper housing 12 and the flange portion 14a of the lower housing 14 are connected to each other by bolting, thereby forming the housing 10.

[0018] The gas turbine 1 having the above configuration includes a cooling device 20 for cooling the upper housing 12. When the gas turbine 1 is stopped, the cooling device 20 supplies a cooling medium to the upper housing 12, which is difficult to cool due to natural convection, thereby making it possible to suppress warping of the housing 10 due to the cat-back phenomenon caused by the difference in deformation amount between the upper housing 12 and the lower housing 14.

[0019] 1, the cooling device 20 includes a cooling medium supply line 22 for supplying a cooling medium. The upstream side of the cooling medium supply line 22 is open to the outside via an inlet filter 26, allowing outside air to be introduced as the cooling medium. The inlet filter 26 is configured to remove foreign matter contained in the introduced cooling medium (outside air).

[0020] The cooling medium supply line 22 is provided with, in order from the upstream side, a flow rate adjustment valve 28, a fan 30, a shutoff valve 32, and a supply valve 34. When the gas turbine 1 is stopped, the shutoff valve 32 and the supply valve 34 are switched from a closed state to an open state, thereby enabling the supply of cooling medium to the upper housing 12. At this time, the fan 30 is operated to take cooling medium from the outside into the cooling medium supply line 22 and blow it against the upper housing 12. The flow rate of the cooling medium in the cooling medium supply line 22 can be controlled by adjusting the opening degree of the flow rate adjustment valve 28.

[0021] Each component provided on the cooling medium supply line 22 (flow rate adjustment valve 28, fan 30, shutoff valve 32, supply valve 34) can be controlled based on a control signal from a control device 54, which will be described later.

[0022] The cooling medium supply line 22 communicates with a cooling flow path 38 formed by a cooling cell 36 attached to the outer peripheral surface of the upper housing 12. As shown in FIGS. 2 and 3 , the cooling cell 36 is a generally inverted U-shaped member, and the opening side of the cooling cell 36 is fixed to the outer peripheral surface of the upper housing 12 to form the cooling flow path 38 surrounded by the cooling cell 36. The downstream end of the cooling medium supply line 22 is connected to one end 38 a of the cooling flow path 38 so as to communicate with the cooling medium, and the cooling medium supplied via the cooling medium supply line 22 is introduced into the cooling flow path 38. In the cooling flow path 38, the upper housing 12 is cooled by heat exchange with the cooling medium. The cooling medium, whose temperature has increased as a result of being used for cooling, is discharged to the outside from the other end 38 b of the cooling flow path 38.

[0023] Next, a cooling device control system (hereinafter referred to as "control system 50") for controlling the cooling device 20 having the above configuration will be described. Fig. 4 is a block diagram of the control system 50 according to one embodiment, and Fig. 5 is a control flow diagram of the second control signal generator 58 in Fig. 4.

[0024] The control system 50 includes a first temperature sensor 51, a second temperature sensor 52, and a control device 54. The first temperature sensor 51 and the second temperature sensor 52 are disposed in at least one of the upper housing 12 and the lower housing 14. The specific locations of the first temperature sensor 51 and the second temperature sensor 52 are not limited as long as they are locations where deformation of the housing due to the cat-back phenomenon can be detected. In this embodiment, a case where the first temperature sensor 51 and the second temperature sensor 52 are disposed in the upper housing 12 and the lower housing 14, respectively, will be described as an example. In this case, the first temperature sensor 51 is disposed in the upper housing 12 and is configured to detect a first temperature T1 of the upper housing 12. The second temperature sensor 52 is disposed in the lower housing 14 and is configured to detect a second temperature T2 of the lower housing 14.

[0025] The first temperature sensor 51 and the second temperature sensor 52 may be disposed in either the upper housing 12 or the lower housing 14. In this case, the first temperature sensor 51 and the second temperature sensor 52 are disposed in different locations in either housing (for example, when one is disposed in the upper part of the housing, the other is disposed in the lower part of the housing).

[0026] The detected values ​​of these temperature sensors are sent to the control device 54 and used for various controls.

[0027] The control device 54 is a control unit of the control system 50 and is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium, for example, in the form of a program. The CPU reads this program into the RAM and executes information processing and arithmetic operations to realize various functions. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0028] As shown in FIG. 4 , the control device 54 includes a first control signal generating unit 56 , a second control signal generating unit 58 , an abnormality determining unit 60 , a switching unit 62 , and a control unit 64 .

[0029] The first control signal generator 56 is configured to generate a first control signal CS1 for controlling the cooling device 20 based on the detection results of the first temperature sensor 51 and the second temperature sensor 52. Specifically, the first control signal generator 56 calculates a temperature difference ΔT between a first temperature T1 of the upper housing 12 detected by the first temperature sensor 51 and a second temperature T2 of the lower housing 14 detected by the second temperature sensor 52, and generates a first control signal CS1 for feedback control of the cooling device 20 so that the temperature difference ΔT falls within a predetermined tolerance range. The first control signal CS1 generated in this manner is a control signal based on the actual measurement values ​​of the first temperature sensor 51 and the second temperature sensor 52.

[0030] The second control signal generating unit 58 is configured to generate, based on control information CI prepared in advance, a second control signal CS2 for controlling the cooling device 20. In this embodiment, the control information CI is stored in advance in the storage unit 66, and the second control signal generating unit 58 can access the storage unit 66 to obtain the control information CI necessary for generating the second control signal CS2.

[0031] The control information CI is prepared as information necessary for reproducing a control signal transmitted to the cooling device 20 when the gas turbine 1 is stopped, when the first temperature sensor 51 and the second temperature sensor 52 are normal. Such control information CI can be obtained, for example, by a test run using the control system 50 in which it is guaranteed that the first temperature sensor 51 and the second temperature sensor 52 are normal. Specifically, when the gas turbine 1 is stopped, the control information CI can be obtained as information for reproducing a control signal transmitted to the cooling device 20 when the control system 50 controls the cooling device 20 based on the detection results of the first temperature sensor 51 and the second temperature sensor 52.

[0032] 5 , the control information CI is prepared as functions fx1, fx2, ... that define the relationship between the elapsed time tr since the gas turbine 1 was shut down and the control parameters included in the first control signal CS1 that is generated when there are no abnormalities in the first temperature sensor 51 and the second temperature sensor 52. In this case, the second control signal generating unit 58 counts the elapsed time tr since the gas turbine 1 was shut down using the elapsed time counting unit 59, and inputs the elapsed time tr to the functions fx1, fx2, ..., thereby being able to determine the corresponding control parameters P1, P2, .... The control parameters P1, P2, ... that have been determined in this manner are output as the second control signal CS2.

[0033] The second control signal CS2 generated in this manner is obtained as a control signal for suitably cooling the upper housing 12 when the gas turbine 1 is stopped, without using the actual measured values ​​of the first temperature sensor 51 and the second temperature sensor 52.

[0034] Here, we will explain a specific example of the second control signal CS2 generated by the second control signal generating unit 58. Fig. 6 shows an example of the change over time in the opening degree of the flow rate adjustment valve 28 in Fig. 1 controlled based on the second control signal generated by the second control signal generating unit 58 in Fig. 5.

[0035] This example shows how the aperture of the flow control valve 28 fluctuates in a predetermined manner over time after the gas turbine 1 is stopped at time t1. Such a change in the aperture of the flow control valve 28 is originally realized by a control signal (first control signal CS1) calculated based on the actual measurement values ​​of the first temperature sensor 51 and the second temperature sensor 52, but the second control signal CS2 is generated based on the control information CI so that the same behavior can be reproduced.

[0036] 4 , the abnormality determination unit 60 is configured to determine whether or not there is an abnormality in the first temperature sensor 51 and the second temperature sensor 52. In one embodiment, the abnormality determination unit 60 acquires the first temperature T1 detected by the first temperature sensor 51 and the second temperature T2 detected by the second temperature sensor 52, and determines whether or not there is an abnormality based on whether or not the respective detected values ​​deviate from a predetermined allowable range. In this case, the allowable range is set as a specification for each of the first temperature sensor 51 and the second temperature sensor 52, and the abnormality determination unit 60 can determine that there is an abnormality in a temperature sensor that has obtained a detected value that deviates from the allowable range based on the specification.

[0037] In another embodiment, the abnormality determination unit 60 may determine an abnormality based on whether the temperature difference ΔT (= T1 - T2) between the first temperature T1 detected by the first temperature sensor 51 and the second temperature T2 detected by the second temperature sensor 52 is outside an allowable range. In this embodiment, the presence or absence of an abnormality can be determined from the perspective of whether the temperature difference calculated from the detection results of the two temperature sensors is a reasonable value. In other words, if the temperature difference ΔT calculated from the detection results of the first temperature sensor 51 and the second temperature sensor 52 is clearly an unreasonable value, there is a high possibility that at least one of the temperature sensors is abnormal, and therefore the abnormality determination unit 60 determines that an abnormality exists.

[0038] The abnormality determination unit 60 of this embodiment combines the determinations according to these two embodiments to determine whether the first temperature sensor 51 and the second temperature sensor 52 are abnormal. That is, the former embodiment determines whether the first temperature sensor 51 and the second temperature sensor 52 are abnormal based on the allowable range of each individual temperature sensor, and the latter embodiment determines whether the first temperature sensor 51 and the second temperature sensor 52 are abnormal based on the allowable value of the temperature difference ΔT obtained from the detection results of the two temperature sensors. In this way, by determining whether the temperature sensors are abnormal from two perspectives, more reliable abnormality determination can be achieved.

[0039] The switching unit 62 is configured to switch, based on the determination result of the abnormality determination unit 60, between the first control signal CS1 generated by the first control signal generation unit 56 and the second control signal CS2 generated by the second control signal generation unit 58 as the control signal to be provided to the control unit 64. Specifically, when the abnormality determination unit 60 determines that there is no abnormality in the first temperature sensor 51 or the second temperature sensor 52, the switching unit 62 switches to select the first control signal CS1 as the control signal. On the other hand, when the abnormality determination unit 60 determines that there is an abnormality in at least one of the first temperature sensor 51 or the second temperature sensor 52, the switching unit 62 switches to select the second control signal CS2 as the control signal.

[0040] The control unit 64 is configured to control the cooling device 20 based on the control signal selected by the switching unit 62. When the abnormality determination unit 60 determines that the first temperature sensor 51 and the second temperature sensor 52 are not abnormal (when the first temperature sensor 51 and the second temperature sensor 52 are normal), the control unit 64 controls the cooling device 20 based on the first control signal CS1. In this case, the cooling device 20 is controlled based on the first control signal CS1 generated based on the detection results of the normal first temperature sensor 51 and the second temperature sensor 52. On the other hand, when the abnormality determination unit 60 determines that at least one of the first temperature sensor 51 and the second temperature sensor 52 is abnormal, the control unit 64 controls the cooling device 20 based on the second control signal CS2. In this case, the cooling device 20 is controlled based on the second control signal CS2 generated based on the control information, without using the detection results of the abnormal first temperature sensor 51 and the second temperature sensor 52.

[0041] Next, a cooling device control method executed by the control device 54 having the above configuration will be described. Fig. 7 is a flowchart showing a cooling device control method according to one embodiment.

[0042] First, the control device 54 determines whether the gas turbine 1 has stopped (step S1). If it is determined that the gas turbine 1 has stopped (step S1: YES), the control device 54 acquires the detected values ​​(first temperature T1 and second temperature T2) of the first temperature sensor 51 and the second temperature sensor 52 (step S2). Then, the abnormality determination unit 60 determines whether at least one of the first temperature sensor 51 and the second temperature sensor 52 has an abnormality, based on the first temperature T1 and the second temperature T2 acquired in step S2 (step S3).

[0043] If the abnormality determination unit 60 determines that the first temperature sensor 51 and the second temperature sensor 52 are normal (step S3: YES), the switching unit 62 switches the control signal so that the first control signal CS1 is selected (step S4). In this case, the control unit 64 controls the cooling device 20 based on the first control signal CS1 selected as the control signal (step S5). As a result, when the first temperature sensor 51 and the second temperature sensor 52 are normal, the cooling control of the upper housing 12 is performed based on the actual measured values ​​of these temperature sensors, thereby making it possible to effectively suppress the cat-back phenomenon.

[0044] On the other hand, if the abnormality determination unit 60 determines that at least one of the first temperature sensor 51 and the second temperature sensor 52 has an abnormality (step S3: NO), the switching unit 62 switches the control signal so that the second control signal CS2 is selected (step S6). In this case, the control unit 64 controls the cooling device 20 based on the second control signal CS2 selected as the control signal (step S5). As a result, when at least one of the first temperature sensor 51 and the second temperature sensor 52 has an abnormality, the cooling device 20 is controlled based on the second control signal CS2 generated using the control information CI without using the detection results of the abnormal first temperature sensor 51 or the second temperature sensor 52, thereby appropriately cooling the upper housing 12 and suppressing the cat-back phenomenon.

[0045] In the above description, the turbine 6 is used in the gas turbine 1 as an example, but may be used in the steam turbine 3. Fig. 8 is an overall configuration diagram that schematically shows the steam turbine 3 according to one embodiment.

[0046] The steam turbine 3 is supplied with steam S as a working fluid from a steam source (not shown), and the steam S drives the turbine 6, thereby driving the generator 9 via the rotating shaft 8. The turbine 6 used in the steam turbine 3 has a configuration substantially similar to that of the turbine 6 used in the gas turbine 1 described above, and can employ the cooling device 20 described above.

[0047] In the configuration example shown in Figure 8, the cooling device 20 has a cooling medium supply line 42 for supplying a cooling medium, similar to the cooling medium supply line 22 described above (note that the cooling medium may be a fluid used as control air in plant facilities such as factories). A flow rate adjustment valve 44 for adjusting the flow rate of the cooling medium and a shutoff valve 46 for shutting off the cooling medium are respectively arranged on the cooling medium supply line 42. The cooling device 20 having such a configuration is controlled in a manner similar to the cooling device 20 used in the gas turbine 1 described above, and thereby supplies a cooling medium to the upper housing of the turbine 6, which is difficult to cool due to natural convection, when the steam turbine 3 is stopped, thereby making it possible to suitably suppress warping of the housing due to the cat-back phenomenon.

[0048] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments may be combined as appropriate.

[0049] The contents described in each of the above embodiments can be understood, for example, as follows.

[0050] (1) A cooling device control system according to one aspect is a cooling device control system for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing including an upper housing and a lower housing is stopped, the cooling device control system comprising: a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; a first control signal generation unit that generates a first control signal for controlling the cooling device based on detection results of the first temperature sensor and the second temperature sensor; a second control signal generation unit that generates a second control signal for controlling the cooling device based on control information prepared in advance; a control unit that controls the cooling device based on the control signal; an abnormality determination unit that determines an abnormality in the first temperature sensor and the second temperature sensor; and a switching unit that switches the control signal to the first control signal or the second control signal when the abnormality determination unit determines that there is no abnormality in the first temperature sensor and the second temperature sensor, and

[0051] According to the above aspect (1), a control signal for a cooling device that cools the upper housing to suppress the cat-back phenomenon when the turbine is stopped can be switched between a first control signal and a second control signal depending on whether or not there is an abnormality in a first temperature sensor and a second temperature sensor provided in at least one of the upper housing and the lower housing. The first control signal is a control signal selected when there is no abnormality in these temperature sensors, and allows cooling control of the upper housing based on actual measured values. On the other hand, the second control signal is a control signal selected when there is an abnormality in at least one of the first temperature sensor and the second temperature sensor, and allows cooling control of the upper housing based on control information prepared in advance. Because the second control signal is a control signal that does not depend on the actual measured values ​​of the temperature sensors, even if an abnormality occurs in at least one of the temperature sensors, the cat-back phenomenon can be suitably suppressed by cooling control of the upper housing by controlling the cooling device based on the control information prepared in advance.

[0052] (2) In another aspect, in the aspect (1) above, the control information is information for obtaining a control signal for feedback controlling the cooling device so that the temperature difference between the first temperature detected by the first temperature sensor and the second temperature detected by the second temperature sensor is within an acceptable range when there is no abnormality in the first temperature sensor and the second temperature sensor.

[0053] According to the above aspect (2), the control information used to generate the second control signal is prepared as information for obtaining a control signal used for feedback control of the cooling device when there is no abnormality in the first temperature sensor and the second temperature sensor. As a result, when an abnormality occurs in at least one of the first temperature sensor and the second temperature sensor, it is possible to obtain the second control signal that can control the cooling device appropriately for cooling the upper housing without using the actual measured values ​​of these temperature sensors.

[0054] (3) In another aspect, in the aspect (1) or (2) above, the control information is a function that defines the relationship between the elapsed time since the turbine was stopped and a control parameter included in the first control signal that is generated when there is no abnormality in the first temperature sensor and the second temperature sensor, and the second control signal generation unit generates the second control signal from the control parameter obtained by inputting the elapsed time into the function.

[0055] According to the above aspect (3), a function defining the relationship between the time elapsed since the turbine was stopped and the control parameter included in the first control signal generated when there is no abnormality in the first temperature sensor and the second temperature sensor is prepared in advance as control information used in generating the second control signal. When it is determined that there is an abnormality in at least one of the first temperature sensor and the second temperature sensor, the time elapsed since the turbine was stopped is input to the prepared function in this way, thereby obtaining the corresponding control parameter, and thereby the second control signal can be suitably generated.

[0056] (4) In another aspect, in any one of the aspects (1) to (3) above, a memory unit for storing the control information is further provided, and the second control signal generation unit is capable of obtaining the control information by accessing the memory unit.

[0057] According to the above aspect (4), the control information used in generating the second control signal is prepared by being stored in advance in the storage unit, and thus when it is determined that at least one of the first temperature sensor and the second temperature sensor is abnormal, the control information necessary for generating the second control signal can be obtained by accessing the storage unit.

[0058] (5) In another aspect, in any one of the aspects (1) to (4) above, the abnormality determination unit determines the abnormality based on whether the temperature detected by the first temperature sensor or the second temperature sensor is outside an allowable range.

[0059] According to the above aspect (5), by comparing the detection value of the temperature sensor with the preset allowable range, it is possible to suitably determine whether the first temperature sensor or the second temperature sensor is abnormal.

[0060] (6) In another aspect, in any one of the aspects (1) to (5) above, the abnormality determination unit determines the abnormality based on whether a temperature difference between the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor is outside an allowable range.

[0061] According to the above aspect (6), by comparing the temperature difference obtained from the detection values ​​of the first temperature sensor and the second temperature sensor with a preset allowable range, an abnormality in the first temperature sensor or the second temperature sensor can be suitably determined.

[0062] (7) In another aspect, in any one of the above aspects (1) to (6), the cooling device includes: a cooling air supply line for supplying cooling air to the upper housing; a flow rate control valve provided on the cooling air supply line for adjusting the flow rate of the cooling air; and a fan provided on the cooling air supply line for sending the cooling air, and the control signal includes a control parameter for controlling the operating state of the flow rate control valve or the fan.

[0063] According to the above aspect (7), the cooling device for cooling the upper housing includes a flow rate adjustment valve and a fan provided on the cooling air supply line, and the control signal includes control parameters corresponding to the components of the cooling device, thereby enabling suitable cooling control of the upper housing.

[0064] (8) In another aspect, in any one of the above aspects (1) to (7), the control information is prepared for each load when the turbine is stopped.

[0065] According to the above aspect (8), the control information used to generate the second control signal is prepared for each load when the turbine is stopped. Since the temperature of the turbine housing depends on the load of the turbine, by preparing the control information for each load when the turbine is stopped, it is possible to preferably perform cooling control for the upper housing when it is determined that there is an abnormality in the temperature sensor. (9) In another aspect, in any one of the above aspects (1) to (8), the first temperature sensor and the second temperature sensor are installed in the upper housing and the lower housing, respectively.

[0066] According to the above aspect (9), the control signal for the cooling device that cools the upper housing to suppress the cat-back phenomenon when the turbine is stopped can be switched between the first control signal and the second control signal depending on whether or not there is an abnormality in the first temperature sensor and the second temperature sensor provided in the upper housing and the lower housing, respectively.

[0067] (10) A cooling device control method according to one aspect is a cooling device control method for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing including an upper housing and a lower housing is stopped, the method comprising: a step of generating a first control signal for controlling the cooling device based on detection results of a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; a step of generating a second control signal for controlling the cooling device based on control information prepared in advance; a step of controlling the cooling device based on the control signal; a step of determining an abnormality in the first temperature sensor and the second temperature sensor; and a step of switching the control signal between the first control signal and the second control signal; when it is determined that there is no abnormality in the first temperature sensor and the second temperature sensor, the control signal is switched to the first control signal; and when it is determined that there is an abnormality in at least one of the first temperature sensor or the second temperature sensor, the control signal is switched to the second control signal.

[0068] According to the above aspect (10), a control signal for a cooling device that cools the upper housing to suppress the cat-back phenomenon when the turbine is stopped can be switched between a first control signal and a second control signal depending on whether or not there is an abnormality in a first temperature sensor and a second temperature sensor provided in at least one of the upper housing and the lower housing. The first control signal is a control signal selected when there is no abnormality in these temperature sensors, and allows cooling control of the upper housing based on actual measured values. On the other hand, the second control signal is a control signal selected when there is an abnormality in at least one of the first temperature sensor and the second temperature sensor, and allows cooling control of the upper housing based on control information prepared in advance. Because the second control signal is a control signal that does not depend on the actual measured values ​​of the temperature sensors, even if an abnormality occurs in at least one of the temperature sensors, the cat-back phenomenon can be suitably suppressed by cooling control of the upper housing by controlling the cooling device based on the control information prepared in advance.

[0069] (11) A cooling device control program according to one aspect is a cooling device control program for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing including an upper housing and a lower housing is stopped, the cooling device control program being capable of executing the following steps on a computer device: generating a first control signal for controlling the cooling device based on detection results of a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; generating a second control signal for controlling the cooling device based on control information prepared in advance; controlling the cooling device based on the control signal; determining whether the first temperature sensor and the second temperature sensor are abnormal; and switching the control signal between the first control signal and the second control signal; when it is determined that there is no abnormality in the first temperature sensor and the second temperature sensor, switching the control signal to the first control signal; and when it is determined that there is an abnormality in at least one of the first temperature sensor or the second temperature sensor, switching the control signal to the second control signal.

[0070] According to the above aspect (11), a control signal for a cooling device that cools the upper housing to suppress the cat-back phenomenon when the turbine is stopped can be switched between a first control signal and a second control signal depending on whether or not there is an abnormality in a first temperature sensor and a second temperature sensor provided in at least one of the upper housing and the lower housing. The first control signal is a control signal selected when there is no abnormality in these temperature sensors, and allows cooling control of the upper housing based on actual measured values. On the other hand, the second control signal is a control signal selected when there is an abnormality in at least one of the first temperature sensor and the second temperature sensor, and allows cooling control of the upper housing based on control information prepared in advance. Because the second control signal is a control signal that does not depend on the actual measured values ​​of the temperature sensors, even if an abnormality occurs in at least one of the temperature sensors, the cat-back phenomenon can be suitably suppressed by cooling control of the upper housing by controlling the cooling device based on the control information prepared in advance.

[0071] REFERENCE SIGNS LIST 1 Gas turbine 2 Compressor 3 Steam turbine 4 Combustor 6 Turbine 8 Rotating shaft 9 Generator 10 Housing 12 Upper housing 14 Lower housing 20 Cooling device 22 Cooling medium supply line 24 Inlet section 26 Inlet filter 28 Flow rate control valve 30 Fan 32 Shutoff valve 34 Supply valve 36 Cooling cell 38 Cooling flow path 42 Cooling medium supply line 44 Flow rate control valve 46 Shutoff valve 50 Control system 51 First temperature sensor 52 Second temperature sensor 54 Control device 56 First control signal generation unit 58 Second control signal generation unit 59 Elapsed time counting unit 60 Abnormality determination unit 62 Switching unit 64 Control unit 66 Storage unit

Claims

1. A cooling device control system for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing comprising an upper housing and a lower housing is stopped, comprising: a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; a first control signal generation unit that generates a first control signal for controlling the cooling device based on detection results of the first temperature sensor and the second temperature sensor; a second control signal generation unit that generates a second control signal for controlling the cooling device based on control information prepared in advance; a control unit that controls the cooling device based on the control signals; an abnormality determination unit that determines an abnormality in the first temperature sensor and the second temperature sensor; and a switching unit that switches the control signal to the first control signal or the second control signal when the abnormality determination unit determines that there is no abnormality in the first temperature sensor and the second temperature sensor, 2. The cooling device control system of claim 1, wherein the control information is information for obtaining a control signal for feedback controlling the cooling device so that the temperature difference between the first temperature detected by the first temperature sensor and the second temperature detected by the second temperature sensor is within an acceptable range when there is no abnormality in the first temperature sensor and the second temperature sensor.

3. A cooling device control system as described in claim 1 or 2, wherein the control information is a function that defines the relationship between the elapsed time since the turbine was stopped and a control parameter included in the first control signal that is generated when there is no abnormality in the first temperature sensor and the second temperature sensor, and the second control signal generation unit generates the second control signal from the control parameter obtained by inputting the elapsed time into the function.

4. A cooling device control system as described in claim 1 or 2, further comprising a memory unit for storing the control information, wherein the second control signal generating unit is capable of obtaining the control information by accessing the memory unit.

5. A cooling device control system as described in claim 1 or 2, wherein the abnormality determination unit determines the abnormality based on whether the temperature detected by the first temperature sensor or the second temperature sensor deviates from an allowable range.

6. A cooling device control system as described in claim 1 or 2, wherein the abnormality determination unit determines the abnormality based on whether the temperature difference between the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor exceeds an allowable range.

7. A cooling device control system as described in claim 1 or 2, wherein the cooling device includes: a cooling air supply line for supplying cooling air to the upper housing; a flow rate adjustment valve provided on the cooling air supply line for adjusting the flow rate of the cooling air; and a fan provided on the cooling air supply line for sending the cooling air, and the control signal includes a control parameter for controlling the operating state of the flow rate adjustment valve or the fan.

8. The cooling device control system according to claim 1 or 2, wherein the control information is prepared for each load when the turbine is stopped.

9. The cooling device control system according to claim 1 or 2, wherein the first temperature sensor and the second temperature sensor are installed in the upper housing and the lower housing, respectively.

10. A cooling device control method for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing comprising an upper housing and a lower housing is stopped, comprising the steps of: generating a first control signal for controlling the cooling device based on detection results from a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; generating a second control signal for controlling the cooling device based on control information prepared in advance; controlling the cooling device based on the control signal; determining whether the first temperature sensor and the second temperature sensor are abnormal; and switching the control signal between the first control signal and the second control signal, wherein if it is determined that there is no abnormality in the first temperature sensor and the second temperature sensor, the control signal is switched to the first control signal; and if it is determined that there is an abnormality in at least one of the first temperature sensor or the second temperature sensor, the control signal is switched to the second control signal.

11. A cooling device control program for controlling a cooling device for cooling an upper housing when a turbine having a turbine casing with an upper housing and a lower housing is stopped, the cooling device control program being capable of executing the following steps on a computer device: generating a first control signal for controlling the cooling device based on detection results from a first temperature sensor and a second temperature sensor installed in at least one of the upper housing or the lower housing; generating a second control signal for controlling the cooling device based on control information prepared in advance; controlling the cooling device based on the control signal; determining whether the first temperature sensor and the second temperature sensor are abnormal; and switching the control signal between the first control signal and the second control signal; wherein the cooling device control program switches the control signal to the first control signal when it is determined that there is no abnormality in the first temperature sensor and the second temperature sensor, and switches the control signal to the second control signal when it is determined that there is an abnormality in at least one of the first temperature sensor or the second temperature sensor.

Images