JP2016211432A - Steam turbine cooling method and steam turbine cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam turbine cooling method and a steam turbine cooling device of which economical efficiency and maintainability can be improved.SOLUTION: A steam turbine cooling method according to an embodiment of this invention is carried out in such a manner that a steam turbine placed on a turbine cooling flow passage ranging from an outside air valve to a steam condenser vacuum pump through the steam turbine and a steam condenser water chamber. Surrounding air is sucked from the outside air valve under operation of the steam condenser vacuum pump through the turbine cooling flow passage. In addition, the surrounding air sucked through the outside air valve is fed into the steam turbine through the turbine cooling flow passage under an operation of the steam condenser vacuum pump and the steam turbine is cooled by the surrounding air fed into the steam turbine. In addition, the surrounding air discharged out of the steam turbine is fed into the steam condenser water chamber through the turbine cooling flow passage under an operation of the steam condenser vacuum pump and the surrounding air fed into the steam condenser water chamber is cooled by the steam condenser water chamber. In addition, the surrounding air cooled at the steam condenser water chamber is sucked through the turbine cooling flow passage under an operation of the steam condenser vacuum pump and discharged out of it.SELECTED DRAWING: Figure 1

Description

  Embodiments according to the present invention relate to a steam turbine cooling method and a steam turbine cooling device.

  When the steam turbine apparatus is regularly inspected or when the steam turbine apparatus is inspected to be open at the time of failure, it is necessary to stop the steam turbine apparatus and cool the high-temperature portion of the steam turbine apparatus. This is because the steam turbine device cannot be disassembled unless it is cooled at a high temperature, and cannot be inspected or repaired.

  Here, the steam discharged from the intermediate pressure turbine is directly introduced into the low pressure turbine of the steam turbine apparatus. For this reason, the temperature of the low-pressure turbine is a relatively low temperature of about 300 ° C. Therefore, the low-pressure turbine can be cooled in a relatively short time if it is left as it is after being stopped.

  On the other hand, main steam generated in the boiler is supplied to the high-pressure turbine in the steam turbine apparatus. Moreover, reheat steam is supplied from a reheater to a medium pressure turbine in the steam turbine apparatus. The main steam and reheat steam are about 500 to 600 ° C. Therefore, the high-pressure turbine and the intermediate-pressure turbine require a long time for cooling when left naturally. And until cooling is completed, inspection and repair cannot be started, and the operation of the turbine device becomes impossible, which hinders power supply.

  For this reason, the high-pressure turbine and the medium-pressure turbine need not be cooled by natural standing (natural cooling), but must be forcedly cooled (forced cooling) by driving the steam turbine device. There has been known a cooling system that forcibly cools each turbine by introducing outside air sucked by a vacuum pump from the steam exhaust portions of the high-pressure turbine and the intermediate-pressure turbine into each turbine. In this cooling system, after cooling each turbine, the high temperature outside air discharged | emitted from the steam introduction part of each turbine is cooled with a cooling device. Then, the outside air cooled by the cooling device is sucked by the vacuum pump and discharged into the atmosphere.

  However, such a conventional cooling system has a large number of components such as a cooling device, a pipe connecting the steam introduction unit and the cooling device, and a pipe for introducing outside air into the steam exhaust unit, although the frequency of use is low. It was necessary to add a large-scale facility. Therefore, the conventional cooling system has a problem that it is not economical. In addition, since it is difficult to keep large-scale additional equipment clean and managed, the conventional cooling system has a problem of poor maintainability.

Japanese Patent Publication No. 3-4723

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a steam turbine cooling method and a steam turbine cooling device that can improve economy and maintainability.

  In the steam turbine cooling method according to the present embodiment, the steam turbine on the turbine cooling flow path from the outside air valve to the condenser vacuum pump via the steam turbine and the condenser water chamber is stopped. Further, outside air is sucked from the outside air valve through the turbine cooling flow path by the condenser vacuum pump. Further, the outside air sucked from the outside air valve is introduced into the steam turbine through the turbine cooling flow path by the condenser vacuum pump, and the steam turbine is cooled by the outside air introduced into the steam turbine. Further, the outside air discharged from the steam turbine is introduced into the condenser water chamber through the turbine cooling flow path by the condenser vacuum pump, and the outside air introduced into the condenser water chamber is cooled by the condenser water chamber. Further, the outside air cooled by the condenser water chamber is sucked and discharged through the turbine cooling flow path by the condenser vacuum pump.

  According to the present invention, economic efficiency and maintainability can be improved.

1 is a conceptual diagram of a steam turbine cooling device 10 and a steam turbine cooling method showing a first embodiment. It is a flowchart of the steam turbine cooling method which shows 1st Embodiment. It is a conceptual diagram of the steam turbine cooling device 10 and the steam turbine cooling method showing the second embodiment. It is a conceptual diagram of the steam turbine cooling device 10 and the steam turbine cooling method which show 3rd Embodiment. It is a block diagram of the steam turbine cooling device 10 which shows 4th Embodiment. It is a flowchart of the steam turbine cooling method which shows 4th Embodiment. It is a block diagram of the steam turbine cooling device 10 which shows the 1st modification of 4th Embodiment. It is a flowchart of the steam turbine cooling method which shows the 1st modification of 4th Embodiment. It is a block diagram of the steam turbine cooling device 10 which shows the 2nd modification of 4th Embodiment. It is a flowchart of the steam turbine cooling method which shows the 2nd modification of 4th Embodiment. It is a conceptual diagram of the steam turbine cooling device 10 and the steam turbine cooling method showing the fifth embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings. This embodiment does not limit the present invention.

(First embodiment)
(Constitution)
First, as a first embodiment, a basic concept of a steam turbine cooling device and a steam turbine cooling method will be described. FIG. 1 is a conceptual diagram of a steam turbine cooling device 10 and a steam turbine cooling method according to the first embodiment.

  As shown in FIG. 1, the steam turbine cooling device 10 of the first embodiment is provided in a steam turbine device 1. Here, before describing the configuration of the steam turbine cooling device 10, the basic configuration of the steam turbine device 1 will be described.

  As shown in FIG. 1, the steam turbine device 1 includes a boiler 11, a high-pressure turbine 12, a reheater 11 a, an intermediate-pressure turbine 13, a low-pressure turbine 14, and a condensate in order from the upstream side in the steam flow. And a container 15. The condenser 15 includes a condenser water chamber 151.

  The steam turbine device 1 includes a main steam pipe 16 that communicates (connects) the boiler 11 and the high-pressure turbine 12. Moreover, the steam turbine apparatus 1 is provided with the low temperature reheat steam piping 17 which connects the high pressure turbine 12 and the reheater 11a. Further, the steam turbine device 1 includes a high-temperature reheat steam pipe 18 that communicates the reheater 11 a with the intermediate pressure turbine 13. The steam turbine device 1 also includes a crossover pipe 101 that communicates the intermediate pressure turbine 13 and the low pressure turbine 14. The main steam pipe 16 is an example of a first steam pipe. The crossover pipe 101 is an example of a second steam pipe.

  Further, the steam turbine device 1 includes a boiler stop valve 100, a main steam stop valve 102, and a steam control valve 103 in order from the upstream side of the steam flow on the main steam pipe 16. 1 indicates a motor M that drives the valve 100. Further, the steam turbine apparatus 1 includes a combination reheat valve 19 on the high-temperature reheat steam pipe 18.

  The steam turbine device 1 is disposed on the condenser 140, a condenser vacuum pump 105 connected to the condenser 15, a pipe 140 that connects the condenser 15 and the condenser vacuum pump 105, and the pipe 140. And a stop valve 104.

  Further, the steam turbine apparatus 1 includes a boiler vent valve 106 connected to the main steam pipe 16 at a connection point 16 a between the boiler stop valve 100 and the steam stop valve 14. Further, the steam turbine device 1 includes a vacuum breaker valve 111 connected to the condenser 15. The boiler vent valve 106 and the vacuum break valve 111 are examples of an outside air valve.

  The steam turbine cooling device 10 is integrally incorporated in the steam turbine device 1 having the above basic configuration.

  Specifically, the steam turbine cooling device 10 includes a turbine cooling flow path including a high pressure turbine cooling flow path P_H and an intermediate pressure turbine cooling flow path P_I, and a control unit 114.

  The high pressure turbine cooling flow path P_H is a flow path of outside air for forcibly cooling the high pressure turbine 12. The high pressure turbine cooling flow path P_H reaches from the boiler vent valve 106 to the condenser vacuum pump 105 via the high pressure turbine 12 and the condenser water chamber 151. Specifically, the high-pressure turbine cooling flow path P_H has a main steam pipe 16 between the boiler vent valve 106 and the high-pressure turbine 12. The high pressure turbine cooling flow path P_H includes a first drain pipe 107 downstream of the high pressure turbine 12. A first drain valve 108 is disposed on the first drain pipe 107. The high-pressure turbine cooling flow path P_H has an exhaust pipe 109. The exhaust pipe 109 is connected to the plurality of drain pipes 107 and 112 on the downstream side, and reaches from the drain pipes 107 and 112 to the condenser vacuum pump 105 via the condenser water chamber 151.

  The intermediate pressure turbine cooling flow path P_I is an external air flow path for forcibly cooling the intermediate pressure turbine 13. The intermediate pressure turbine cooling flow path P_I reaches from the vacuum breaker valve 111 to the condenser vacuum pump 105 via the intermediate pressure turbine 13 and the condenser water chamber 151. Specifically, the intermediate pressure turbine cooling flow path P_I includes a condenser 15 and a low pressure turbine 14. Further, the intermediate pressure turbine cooling flow path P_I includes a crossover pipe 101 between the low pressure turbine 14 and the intermediate pressure turbine 13. Further, the intermediate pressure turbine cooling flow path P_I includes a second drain pipe 112 downstream of the intermediate pressure turbine 13. A second drain valve 113 is disposed on the second drain pipe 112. Further, the intermediate pressure turbine cooling flow path P_I has an exhaust pipe 109.

  The control unit 114 controls various control target devices of the steam turbine apparatus 1. Specifically, the control unit 114 controls the operation of the condenser vacuum pump 105. The control unit 114 also controls the operations of the turbines 12 to 14 and the valves 19, 100, 102, 103, 104, 106, 108, 111, 113. The control unit 114 may be embodied by one or a plurality of computers.

(Normal operation)
Next, normal operation of the steam turbine apparatus 1 having the above configuration will be described.

  In normal operation, the control unit 114 closes the boiler vent valve 106 and shuts off the high-pressure turbine cooling flow path P_H. Further, the control unit 114 closes the vacuum breaker valve 111 and shuts off the intermediate pressure turbine cooling flow path P_I. On the other hand, the control unit 114 opens the valves 100, 102, 103 on the main steam pipe 16 and the combination reheat valve 19 on the high-temperature reheat steam pipe 18 to open the steam flow path. Further, the control unit 114 opens the stop valve 104 to ensure the exhaust (vacuum degree) of the condenser 15 by the condenser vacuum pump 105.

  And the boiler 11 produces | generates a vapor | steam by heating the water supplied by the condensate pump etc. which are not shown from the condenser 15 side. The steam generated in the boiler 11 passes through the main steam pipe 16, sequentially passes through the boiler stop valve 100, the main steam stop valve 102, and the steam control valve 103, and is introduced into the high-pressure turbine 12. The steam introduced into the high-pressure turbine 12 is discharged from the high-pressure turbine 12 after rotating the rotor of the high-pressure turbine 12.

  The steam discharged from the high-pressure turbine 12 is introduced into the reheater 11a through the low-temperature reheated steam pipe 17, and is reheated by the reheater 11a. The steam reheated by the reheater 11 a is introduced into the intermediate pressure turbine 13 through the high-temperature reheat steam pipe 18 and the combination reheat valve 19. The steam introduced into the intermediate pressure turbine 13 is discharged from the intermediate pressure turbine 13 after rotating the rotor of the intermediate pressure turbine 13.

  The steam discharged from the intermediate pressure turbine 13 is introduced into the low pressure turbine 14 through the crossover pipe 101. The steam introduced into the low-pressure turbine 14 is discharged from the low-pressure turbine 14 after rotating the rotor of the low-pressure turbine 14. The steam discharged from the low-pressure turbine 14 is collected in the condenser 15 as a drain that has changed into water.

(Forced cooling)
Next, forced cooling of the high pressure turbine 12 and the intermediate pressure turbine 13 will be described. FIG. 2 is a flowchart of the steam turbine cooling method according to the first embodiment.

  In forced cooling, the control unit 114 stops the turbines 12 to 14 in the operating state (step S1). In addition, the control unit 114 closes the boiler stop valve 100 and the combination reheat valve 19 to block the steam flow path. Further, the control unit 114 closes the stop valve 104 and prohibits the condenser 15 from being exhausted by the condenser vacuum pump 105. On the other hand, the controller 114 opens the high pressure turbine cooling flow path P_H by opening the boiler vent valve 106, the main steam stop valve 102, the steam control valve 103, and the first drain valve 108. Further, the control unit 114 opens the vacuum breaker valve 111 and the second drain valve 113 to open the intermediate pressure turbine cooling flow path P_I.

  Then, the control unit 114 drives the condenser vacuum pump 105. The driven condenser vacuum pump 105 generates negative pressure in the high pressure turbine cooling flow path P_H and the intermediate pressure turbine cooling flow path P_I by suction. Thereby, the condenser vacuum pump 105 sucks outside air from the boiler vent valve 106 through the high-pressure turbine cooling flow path P_H (step S2_1). Further, the condenser vacuum pump 105 sucks outside air from the vacuum breaker valve 111 through the intermediate pressure turbine cooling flow path P_I (step S2_2). Thereafter, outside air continues to be sucked into the flow paths P_H and P_I by the condenser vacuum pump 105 until it is discharged from the condenser vacuum pump 105 into the atmosphere.

  Next, the outside air sucked from the boiler vent valve 106 is introduced into the high-pressure turbine 12 through the high-pressure turbine cooling flow path P_H (step S3_1). The high-pressure turbine 12 is forcibly cooled by heat exchange with the outside air introduced into the high-pressure turbine 12. Conversely, the outside air introduced into the high pressure turbine 12 is heated as the high pressure turbine 12 is cooled. On the other hand, the outside air sucked from the vacuum breaker valve 111 is introduced into the intermediate pressure turbine 13 through the intermediate pressure turbine cooling flow path P_I (step S3_2). The intermediate pressure turbine 13 is forcibly cooled by heat exchange with the outside air introduced into the intermediate pressure turbine 13. On the contrary, the outside air introduced into the intermediate pressure turbine 13 is heated as the intermediate pressure turbine 13 is cooled.

  Next, the outside air that has cooled the high-pressure turbine 12 is discharged from the high-pressure turbine 12. The outside air discharged from the high-pressure turbine 12 is introduced into the condenser water chamber 151 through the high-pressure turbine cooling channel P_H (step S4_1). On the other hand, the outside air that has cooled the intermediate pressure turbine 13 is discharged from the intermediate pressure turbine 13. The outside air discharged from the intermediate pressure turbine 13 is introduced into the condenser water chamber 151 through the intermediate pressure turbine cooling flow path P_I (step S4_2). The high temperature outside air introduced into the condenser water chamber 151 is cooled by heat exchange with the condenser water chamber 151.

  Next, the condenser vacuum pump 105 sucks the outside air cooled in the condenser water chamber 151 through the turbine cooling passages P_H and P_I and discharges it into the atmosphere (step S5).

  If the outside air heated by heat exchange with the turbines 12 and 13 is sucked by the condenser vacuum pump 105 as it is, the condenser vacuum pump 105 may break down due to the heat of the outside air. On the other hand, in this embodiment, failure of the condenser vacuum pump 105 can be prevented by cooling the outside air and sucking it with the condenser vacuum pump 105. The condenser water chamber 151 is originally filled with cooling water (for example, seawater) as a heat exchange source for condensing steam. In this embodiment, outside air can be cooled by heat exchange with such an existing condenser water chamber 151.

  According to the first embodiment, the high-pressure turbine 12 and the intermediate-pressure turbine 13 can be forcibly cooled by a simple and small configuration in which the exhaust pipe 109 is additionally provided in the existing equipment. Thereby, economical efficiency and maintainability can be improved.

(Second Embodiment)
Next, as a second embodiment, a specific configuration example that achieves both recovery of drain from the turbines 12 and 13 and forced cooling of the turbines 12 and 13 will be described. In the description of the second embodiment, the same reference numerals are used for the components corresponding to the first embodiment, and a duplicate description is omitted. FIG. 3 is a conceptual diagram of the steam turbine cooling device 10 and the steam turbine cooling method showing the second embodiment.

  It is desirable to collect the drain generated in the high-pressure turbine 12 and the intermediate-pressure turbine 19 in the condenser 15 in the same manner as the drain generated in the low-pressure turbine 14 is collected in the condenser 15. Therefore, as shown in FIG. 3, the first drain pipe 107 has a connection portion 107 b connected to the condenser 15. The second drain pipe 112 also has a connection part 112 b connected to the condenser 15.

  On the other hand, a part 107a of the first drain pipe 107 branches off at the connecting portion 107b and the branch point p1 and is connected to the exhaust pipe 109 so that the high-pressure turbine cooling flow path P_H can be formed. In addition, a portion 112a of the second drain pipe 112 is branched at the connecting portion 112b and the branch point p2 and connected to the exhaust pipe 109 so that the intermediate pressure turbine cooling flow path P_I can be formed. The part 107a of the first drain pipe 107 and the part 112a of the second drain pipe 112 may be part of the exhaust pipe 109.

  Further, a first stop valve 115 is disposed on the first drain pipe 107a between the branch point p1 and the exhaust pipe 109. A second stop valve 116 is disposed on the second drain pipe 112a between the branch point p2 and the exhaust pipe 109. Operations of the first stop valve 115 and the second stop valve 116 may be controlled by the control unit 114.

  When the steam turbine apparatus 1 of the second embodiment having the above configuration is normally operated, the control unit 114 closes both the first stop valve 115 and the second stop valve 116. Thereby, it is possible to prevent the drain generated in the high-pressure turbine 12 and the intermediate-pressure turbine 13 from flowing into the condenser vacuum pump 105.

  On the other hand, when the high pressure turbine 12 and the intermediate pressure turbine 13 are forcibly cooled, the control unit 114 opens both the first stop valve 115 and the second stop valve 116. Thereby, the high pressure turbine cooling flow path P_H and the intermediate pressure turbine cooling flow path P_I can be opened. In consideration of the possibility of high-temperature outside air flowing into the condenser 15, it is preferable to activate the condensate pump and operate the water curtain spray.

  As described above, according to the second embodiment, the first drain pipe 107 and the second drain pipe 114 are drained and the turbines 12 and 13 are forcedly cooled according to the opening and closing of the stop valves 115 and 116. And can be selectively used for either. Therefore, according to the second embodiment, drain recovery and forced cooling of the turbines 12 and 13 can both be achieved with a simple configuration.

(Third embodiment)
Next, an embodiment for cooling the main steam stop valve 102 and the steam control valve 103 will be described as a third embodiment. In the description of the third embodiment, the same reference numerals are used for the components corresponding to the first embodiment, and a duplicate description is omitted. FIG. 4 is a conceptual diagram of the steam turbine cooling device 10 and the steam turbine cooling method according to the third embodiment.

  As shown in FIG. 4, in addition to the configuration of the first embodiment, the steam turbine cooling device 10 of the third embodiment includes a main steam stop valve cooling channel P_MSV and a steam control valve cooling channel P_CV. Prepare.

  The main steam stop valve cooling flow path P_MSV is a flow path of outside air for cooling the main steam stop valve 102. The main steam stop valve cooling flow path P_MSV branches from the high-pressure turbine cooling flow path P_H at a first branch point p3 between the main steam stop valve 102 and the steam control valve 103. Further, the main steam stop valve cooling flow path P_MSV merges with the high pressure turbine cooling flow path P_H at the merge point p4 between the high pressure turbine 12 and the condenser water chamber 151. Specifically, the main steam stop valve cooling flow path P_MSV has a main steam pipe 16. The main steam stop valve cooling flow path P_MSV includes a third drain pipe 117 connected to the main steam pipe 16 at the first branch point p3. A third drain valve 118 is disposed on the third drain pipe 117. Further, the main steam stop valve cooling flow path P_MSV has an exhaust pipe 109. In the third embodiment, a third drain pipe 117 and a later-described fourth drain pipe 119 are added to the drain pipe connected to the exhaust pipe 109. As shown in FIG. 4, a junction p4 between the main steam stop valve cooling flow path P_MSV and the high pressure turbine cooling flow path P_H exists in the exhaust pipe 109.

  The steam control valve cooling flow path P_CV is a flow path of outside air that cools the steam control valve 103. The steam control valve cooling flow path P_CV branches from the high pressure turbine cooling flow path P_H at a second branch point p5 between the steam control valve 103 and the high pressure turbine 12. Further, the steam control valve cooling flow path P_CV joins the high pressure turbine cooling flow path P_H at a junction p4 between the high pressure turbine 12 and the condenser water chamber 151. Specifically, the steam control valve cooling flow path P_CV has a main steam pipe 16. The steam control valve cooling flow path P_CV includes a fourth drain pipe 119 connected to the main steam pipe 16 at the second branch point p5. A fourth drain valve 120 is disposed on the fourth drain pipe 119. Further, the steam control valve cooling flow path P_CV has an exhaust pipe 109.

  The operations of the third drain valve 118 and the fourth drain valve 120 may be controlled by the control unit 114.

  When the high pressure turbine 12 is forcibly cooled by the steam turbine apparatus 1 of the third embodiment having the above configuration, the control unit 114 opens both the third drain valve 118 and the fourth drain valve 120. Thereby, the main steam stop valve cooling flow path P_MSV and the steam control valve cooling flow path P_CV are opened.

  When the condenser vacuum pump 105 sucks outside air from the boiler vent valve 106 through the high-pressure turbine cooling passage P_H, the condenser vacuum pump 105 also sucks outside air through the main steam stop valve cooling passage P_MSV. At this time, the condenser vacuum pump 105 also sucks outside air through the steam control valve cooling flow path P_CV.

  The outside air flowing through the main steam stop valve cooling flow path P_MSV is branched from the outside air flowing through the high-pressure turbine cooling flow path P_H at the first branch point p3, and then merges at the merge point p4. Further, the outside air flowing through the steam control valve cooling flow path P_CV is diverted from the outside air flowing through the high-pressure turbine cooling flow path P_H at the second branch point p5, and then merges at the merge point p4. The outside air flowing through the main steam stop valve cooling flow path P_MSV and the outside air flowing through the steam control valve cooling flow path P_CV are diverted at the first branch point p3 and then merged at a merge point p6 upstream from the merge point p4. The

  At this time, the flow rate of the outside air passing through the main steam stop valve 102 can be increased by sucking the outside air through the main steam stop valve cooling flow path P_MSV. Thereby, the cooling rate of the main steam stop valve 102 can be improved. Further, by sucking the outside air through the steam control valve cooling flow path P_CV, the flow rate of the outside air passing through the steam control valve 103 can be increased. Thereby, the cooling rate of the steam control valve 103 can be improved. The outside air that has cooled the main steam stop valve 102 and the steam control valve 103 is cooled in the condenser water chamber 151 and then exhausted from the condenser vacuum pump 105 to the atmosphere.

  As described above, according to the third embodiment, the cooling rate of the main steam stop valve 102 can be improved by sucking outside air through the main steam stop valve cooling flow path P_MSV. Moreover, the cooling rate of the steam control valve 103 can be improved by sucking outside air through the steam control valve cooling flow path P_CV. As a result, the time required from when the steam turbine device 1 is stopped until the main steam stop valve 102 and the steam control valve 103 can be disassembled can be shortened, so that the main steam stop valve 102 and the steam control valve 103 can be quickly inspected or repaired. it can.

(Fourth embodiment)
Next, an embodiment in which the turbines 12 and 13 are forcibly cooled according to the metal temperature of the steam turbine apparatus 1 will be described as a fourth embodiment. In the description of the fourth embodiment, the same reference numerals are used for the components corresponding to the first embodiment, and a duplicate description is omitted. FIG. 5 is a block diagram of the steam turbine cooling device 10 showing the fourth embodiment.

  As shown in FIG. 5, in addition to the configuration of the first embodiment, the steam turbine cooling device 10 of the fourth embodiment further includes a high-pressure turbine temperature detector 122, an intermediate-pressure turbine temperature detector 123, A temperature drop rate calculation unit 1141.

  The high pressure turbine temperature detector 122 is disposed in the high pressure turbine 12. The high-pressure turbine temperature detector 122 detects the temperature of the metal portion of the high-pressure turbine 12 (hereinafter also referred to as high-pressure turbine metal temperature), and outputs a detection signal indicating the detected high-pressure turbine metal temperature to the temperature drop rate calculation unit 1141. .

  The intermediate pressure turbine temperature detector 123 is disposed in the intermediate pressure turbine 13. The intermediate pressure turbine temperature detector 123 detects the temperature of the metal portion of the intermediate pressure turbine 13 (hereinafter also referred to as intermediate pressure turbine metal temperature), and generates a detection signal indicating the detected intermediate pressure turbine metal temperature as a temperature drop rate calculation unit. It outputs to 1141.

  The temperature drop rate calculation unit 1141 is built in the control unit 114. Based on the detection signal input from the high pressure turbine temperature detector 122, the temperature drop rate calculation unit 1141 calculates the temperature drop rate of the high pressure turbine metal indicating how many times the high pressure turbine metal temperature has dropped in a unit time. Further, the temperature drop rate calculation unit 1141 shows the temperature drop of the medium pressure turbine metal indicating how many times the medium pressure turbine metal temperature has dropped in a unit time based on the detection signal input from the medium pressure turbine temperature detector 123. Calculate the rate.

  The control unit 114 controls the opening degree of the boiler vent valve 106 by outputting an opening degree control signal corresponding to the temperature drop rate of the high-pressure turbine metal calculated by the temperature drop rate calculation unit 1141 to the boiler vent valve 106. Further, the control unit 114 outputs an opening degree control signal corresponding to the temperature drop rate of the medium pressure turbine metal calculated by the temperature drop rate calculation unit 1141 to the vacuum break valve 111, thereby opening the vacuum break valve 111. Control the degree.

  Next, a steam turbine cooling method according to a fourth embodiment to which the steam turbine apparatus 1 having the above configuration is applied will be described. FIG. 6 is a flowchart of the steam turbine cooling method according to the fourth embodiment.

  First, the high pressure turbine temperature detector 122 detects the high pressure turbine metal temperature (S11_1). At this time, the intermediate pressure turbine temperature detector 123 detects the intermediate pressure turbine metal temperature (S11_2).

  Next, the temperature drop rate calculation unit 1141 calculates the temperature drop rate of the high-pressure turbine metal (S12_1). At this time, the temperature drop rate calculation unit 1141 calculates the temperature drop rate of the medium-pressure turbine metal (S12_2).

  Next, the control unit 114 determines whether or not the temperature drop rate of the high-pressure turbine metal is large (S13_1). This determination may be based on whether the temperature drop rate of the high-pressure turbine metal is greater than a previously acquired threshold value (upper limit value). Further, the control unit 114 determines whether or not the temperature drop rate of the medium pressure turbine metal is large (S13_2). This determination may be based on whether or not the temperature drop rate of the medium-pressure turbine metal is greater than a previously acquired threshold value (upper limit value).

  When the temperature drop rate of the high-pressure turbine metal is large (S13_1: Yes), the control unit 114 controls the boiler vent valve 106 so as to close the boiler vent valve 106 (S16_1). Thereafter, the process proceeds to detection of the high-pressure turbine metal temperature (S11_1). When the temperature drop rate of the medium pressure turbine metal is large (S13_2: Yes), the control unit 114 controls the vacuum break valve 111 so as to close the vacuum break valve 111 (S16_2). Thereafter, the process proceeds to detection of the intermediate-pressure turbine metal temperature (S11_2).

  On the other hand, when the temperature drop rate of the high pressure turbine metal is not large (S13_1: No), the control unit 114 determines whether or not the temperature drop rate of the high pressure turbine metal is small (S14_1). This determination may be based on whether the temperature drop rate of the high-pressure turbine metal is smaller than a previously acquired threshold value (lower limit value). When the temperature drop rate of the medium pressure turbine metal is not large (S13_2: No), the control unit 114 determines whether or not the temperature drop rate of the medium pressure turbine metal is small (S14_2). This determination may be based on whether or not the temperature drop rate of the medium-pressure turbine metal is smaller than a previously acquired threshold value (lower limit value).

  When the temperature drop rate of the high-pressure turbine metal is small (S14_1: Yes), the control unit 114 controls the boiler vent valve 106 to open the boiler vent valve 106 (S17_1). Thereafter, the process proceeds to detection of the high-pressure turbine metal temperature (S11_1). When the temperature drop rate of the medium pressure turbine metal is small (S14_2: Yes), the control unit 114 controls the vacuum break valve 111 to open the vacuum break valve 111 (S17_2). Thereafter, the process proceeds to detection of the intermediate-pressure turbine metal temperature (S11_2).

  On the other hand, when the temperature drop rate of the high-pressure turbine metal is not small (S14_1: No), the control unit 114 determines whether or not the high-pressure turbine metal temperature has reached the target temperature (S15_1). When the temperature drop rate of the medium pressure turbine metal is not small (S14_2: No), the control unit 114 determines whether or not the medium pressure turbine metal temperature has reached the target temperature (S15_2).

  When the high-pressure turbine metal temperature reaches the target temperature (S15_1: Yes), forced cooling of the high-pressure turbine 12 is terminated. When the intermediate pressure turbine metal temperature has reached the target temperature (S15_2: Yes), the forced cooling of the intermediate pressure turbine 13 is terminated.

  On the other hand, when the high-pressure turbine metal temperature does not reach the target temperature (S15_1: No), the process proceeds to detection of the high-pressure turbine metal temperature (S11_1). Further, when the intermediate pressure turbine metal temperature does not reach the target temperature (S15_2: No), the process proceeds to detection of the intermediate pressure turbine metal temperature (S11_2).

  If the turbines 12 and 13 are cooled rapidly, the life of the turbines 12 and 13 may be shortened. On the other hand, according to the fourth embodiment, when the temperature drop rate of the high-pressure turbine metal and the medium-pressure turbine metal is large, the boiler vent valve 106 and the vacuum breaker valve 111 can be closed. 13 quenching can be suppressed. On the other hand, when the temperature drop rate of the high-pressure turbine metal and the medium-pressure turbine metal is small, the boiler vent valve 106 and the vacuum breaker valve 111 can be opened, so that the turbines 12 and 13 can be forcibly cooled.

  Therefore, according to the fourth embodiment, forced cooling of the turbines 12 and 13 considering the life of the turbines 12 and 13 can be realized with a simple configuration.

(First modification)
Next, as a first modification of the fourth embodiment, an example in which the turbines 12 and 13 are forcibly cooled according to the temperature difference between the upper half and the lower half of the casings of the turbines 12 and 13 will be described. In the description of the first modification, the same reference numerals are used for the components corresponding to those in FIG. FIG. 7 is a block diagram of a steam turbine cooling device 10 showing a first modification of the fourth embodiment.

  As shown in FIG. 7, in addition to the configuration of the first embodiment, the steam turbine cooling device 10 of the first modified example further includes a first high-pressure turbine temperature detector 125 and a second high-pressure turbine temperature detector. 126, a first intermediate pressure turbine temperature detector 127, a second intermediate pressure turbine temperature detector 128, and a first temperature difference calculation unit 1142.

  The first high pressure turbine temperature detector 125 is disposed in the upper half of the casing (metal part) of the high pressure turbine 12. The first high-pressure turbine temperature detector 125 detects the temperature of the upper half of the casing of the high-pressure turbine 12 (hereinafter also referred to as the upper half temperature), and calculates a first temperature difference from a detection signal indicating the upper half temperature. Output to the unit 1142.

  The second high pressure turbine temperature detector 126 is disposed in the lower half of the casing of the high pressure turbine 12. The second high pressure turbine temperature detector 126 detects the temperature of the lower half of the casing of the high pressure turbine 12 (hereinafter also referred to as the lower half temperature), and calculates a first temperature difference from a detection signal indicating the lower half temperature. Output to the unit 1142.

  The first intermediate pressure turbine temperature detector 127 is disposed in the upper half of the casing (metal part) of the intermediate pressure turbine 13. The first intermediate pressure turbine temperature detector 127 detects the temperature of the upper half of the casing of the intermediate pressure turbine 13 (hereinafter also referred to as the upper half temperature) and outputs a detection signal indicating the upper half temperature to the first temperature. The difference is output to the difference calculation unit 1142.

  The second intermediate pressure turbine temperature detector 128 is disposed in the lower half of the casing of the intermediate pressure turbine 13. The second intermediate pressure turbine temperature detector 128 detects the temperature of the lower half of the casing of the intermediate pressure turbine 13 (hereinafter also referred to as the lower half temperature), and outputs a detection signal indicating the lower half temperature as the first temperature. The difference is output to the difference calculation unit 1142.

  The first temperature difference calculation unit 1142 is built in the control unit 114. The first temperature difference calculation unit 1142 is configured to detect the casing of the high pressure turbine 12 based on the detection signal input from the first high pressure turbine temperature detector 125 and the detection signal input from the second high pressure turbine temperature detector 126. The temperature difference between the upper half and the lower half (hereinafter referred to as the upper and lower temperature difference) is calculated. In addition, the first temperature difference calculation unit 1142 is based on the detection signal input from the first intermediate pressure turbine temperature detector 127 and the detection signal input from the second intermediate pressure turbine temperature detector 128. A temperature difference between the upper half portion and the lower half portion of the casing of the turbine 13 (hereinafter referred to as the upper and lower temperature difference) is calculated.

  The control unit 114 controls the opening degree of the boiler vent valve 106 by outputting an opening degree control signal corresponding to the upper and lower temperature difference of the high-pressure turbine 12 calculated by the first temperature difference calculation unit 1142 to the boiler vent valve 106. . Further, the control unit 114 outputs an opening degree control signal corresponding to the upper and lower temperature difference of the intermediate pressure turbine 13 calculated by the first temperature difference calculation unit 1142 to the vacuum breaker valve 111, so that the vacuum breaker valve 111 Control the opening.

  Next, the steam turbine cooling method of the 1st modification to which the steam turbine apparatus 1 which has the above structure is applied is demonstrated. FIG. 8 is a flowchart of the steam turbine cooling method showing a first modification of the fourth embodiment.

  First, the first high-pressure turbine temperature detector 125 detects the upper half temperature of the high-pressure turbine 12, and the second high-pressure turbine temperature detector 126 detects the lower half temperature of the high-pressure turbine 12 (S21_1). At this time, the first intermediate pressure turbine temperature detector 127 detects the upper half temperature of the intermediate pressure turbine 13, and the second intermediate pressure turbine temperature detector 128 detects the lower half temperature of the intermediate pressure turbine 13. (S21_2).

  Next, the first temperature difference calculation unit 1142 calculates the upper and lower temperature difference of the high-pressure turbine 12 (S22_1). At this time, the first temperature difference calculation unit 1142 calculates the upper and lower temperature difference of the intermediate pressure turbine 13 (S22_2).

  Next, the control unit 114 determines whether or not the temperature difference between the high pressure turbine 12 and the high pressure turbine 12 is large (S23_1). This determination may be based on whether the upper and lower temperature difference of the high-pressure turbine 12 is greater than a previously acquired threshold value (upper limit value). Moreover, the control part 114 determines whether the up-and-down temperature difference of the intermediate pressure turbine 13 is large (S23_2). This determination may be based on whether or not the temperature difference between the upper and lower temperatures of the intermediate pressure turbine 13 is greater than a previously acquired threshold value (upper limit value).

  When the difference in the upper and lower temperature of the high-pressure turbine 12 is large (S23_1: Yes), the control unit 114 controls the boiler vent valve 106 so as to close the boiler vent valve 106 (S25_1). Thereafter, the process proceeds to detection of the upper half temperature and the lower half temperature of the high-pressure turbine 12 (S21_1). When the difference in the upper and lower temperature of the intermediate pressure turbine 13 is large (S23_2: Yes), the control unit 114 controls the vacuum break valve 111 so as to close the vacuum break valve 111 (S25_2). Thereafter, the process proceeds to detection of the upper half temperature and the lower half temperature of the intermediate pressure turbine 13 (S21_2).

  On the other hand, when the upper and lower temperature difference of the high pressure turbine 12 is not large (S23_1: No), the control unit 114 determines whether or not the upper half temperature and the lower half temperature of the high pressure turbine 12 have reached the target temperature ( S24_1). When the difference in the upper and lower temperature of the intermediate pressure turbine 13 is not large (S23_2: No), the control unit 114 determines whether the upper half temperature and the lower half temperature of the intermediate pressure turbine 13 have reached the target temperature. (S24_2).

  When the upper half temperature and the lower half temperature of the high pressure turbine 12 reach the target temperatures (S24_1: Yes), the forced cooling of the high pressure turbine 12 is terminated. When the upper half temperature and the lower half temperature of the intermediate pressure turbine 13 reach the target temperatures (S24_2: Yes), the forced cooling of the intermediate pressure turbine 13 is terminated.

  On the other hand, when the upper half temperature and the lower half temperature of the high pressure turbine 12 do not reach the target temperatures (S24_1: No), the process proceeds to detection of the upper half temperature and the lower half temperature of the high pressure turbine 12 (S21_1). . When the upper half temperature and the lower half temperature of the intermediate pressure turbine 13 have not reached the target temperature (S24_2: No), the upper half temperature and the lower half temperature of the intermediate pressure turbine 13 are detected (S21_2). Transition.

  If the upper and lower temperature difference between the turbines 12 and 13 is large, the casings of the turbines 12 and 13 may be abnormally deformed. On the other hand, according to the first modification, when the vertical temperature difference between the turbines 12 and 13 is large, the boiler vent valve 106 and the vacuum breaker valve 111 can be closed. The difference can be suppressed. On the other hand, when the temperature difference between the turbines 12 and 13 is small, the boiler vent valve 106 and the vacuum breaker valve 111 can be opened, so that the turbines 12 and 13 can be forcibly cooled.

  Therefore, according to the first modification, forced cooling of the turbines 12 and 13 that suppresses abnormal deformation of the casings of the turbines 12 and 13 can be realized with a simple configuration.

(Second modification)
Next, an example in which the turbines 12 and 13 are forcibly cooled according to the temperatures of the main steam stop valve 102 and the steam control valve 103 will be described as a second modification of the fourth embodiment. In the description of the second modification, the same reference numerals are used for the components corresponding to those in FIG. FIG. 9 is a block diagram of a steam turbine cooling device 10 showing a second modification of the fourth embodiment.

  As shown in FIG. 9, in addition to the configuration of the first embodiment, the steam turbine cooling device 10 of the second modification further includes a first main steam stop valve temperature detector 131 and a second main steam stop. A valve temperature detector 132, a first steam control valve temperature detector 133, a second steam control valve temperature detector 134, and a second temperature difference calculation unit 1143 are provided.

  The first main steam stop valve temperature detector 131 is disposed, for example, on the outer surface of the metal portion of the main steam stop valve 102. The metal part of the main steam stop valve 102 may be a valve box or the like. The first main steam stop valve temperature detector 131 detects the temperature of the outer surface of the metal portion of the main steam stop valve 102 (hereinafter also referred to as the outer surface temperature), and outputs a detection signal indicating the outer surface temperature to the second temperature difference calculation unit. 1143 is output.

  The second main steam stop valve temperature detector 132 is disposed, for example, on the inner surface of the metal portion of the main steam stop valve 102. The second main steam stop valve temperature detector 132 detects the temperature of the inner surface of the metal part of the main steam stop valve 102 (hereinafter also referred to as the inner surface temperature), and outputs a detection signal indicating the inner surface temperature to the second temperature difference calculation unit. 1143 is output.

  The first steam control valve temperature detector 133 is disposed, for example, on the outer surface of the metal portion of the steam control valve 103. The metal part of the steam control valve 103 may be a valve box or the like. The first steam control valve temperature detector 133 detects the temperature of the outer surface of the metal portion of the steam control valve 103 (hereinafter also referred to as the outer surface temperature), and sends a detection signal indicating the outer surface temperature to the second temperature difference calculation unit 1143. Output.

  The second steam control valve temperature detector 134 is disposed, for example, on the inner surface of the metal portion of the steam control valve 103. The second steam control valve temperature detector 134 detects the temperature of the inner surface of the metal part of the steam control valve 103 (hereinafter also referred to as the inner surface temperature) and sends a detection signal indicating the inner surface temperature to the second temperature difference calculation unit 1143. Output.

  The second temperature difference calculation unit 1143 is built in the control unit 114. Based on the detection signal input from the first main steam stop valve temperature detector 131 and the detection signal input from the second main steam stop valve temperature detector 132, the second temperature difference calculation unit 1143 A difference between the outer surface temperature and the inner surface temperature of the stop valve 102 (hereinafter also referred to as an inner / outer surface temperature difference) is calculated. Further, the second temperature difference calculation unit 1143 is based on the detection signal input from the first steam control valve temperature detector 133 and the detection signal input from the second steam control valve temperature detector 134. A difference between the outer surface temperature and the inner surface temperature of the valve 103 (hereinafter also referred to as an inner / outer surface temperature difference) is calculated.

  The control unit 114 outputs to the boiler vent valve 106 an opening degree control signal corresponding to the temperature difference between the main steam stop valve 102 and the steam control valve 103 calculated by the second temperature difference calculation unit 1143, so that the boiler vent The opening degree of the valve 106 is controlled.

  Next, the steam turbine cooling method of the 2nd modification to which the steam turbine apparatus 1 which has the above structure is applied is demonstrated. FIG. 10 is a flowchart of a steam turbine cooling method showing a second modification of the fourth embodiment.

  First, the first main steam stop valve temperature detector 131 detects the inner surface temperature of the main steam stop valve 102, and the second main steam stop valve temperature detector 132 detects the outer surface temperature of the main steam stop valve 102 ( S31).

  Next, the first steam control valve temperature detector 133 detects the inner surface temperature of the steam control valve 103, and the second steam control valve temperature detector 134 detects the outer surface temperature of the steam control valve 103 (S32).

  Next, the second temperature difference calculation unit 1143 calculates the inner and outer surface temperature differences of the main steam stop valve 102 and the steam control valve 103 (S33).

  Next, the control unit 114 determines whether or not the temperature difference between the inner and outer surfaces of the main steam stop valve 102 or the steam control valve 103 is large (S34). This determination may be based on whether or not the temperature difference between the inner and outer surfaces of the main steam stop valve 102 and the steam control valve 103 is larger than a previously acquired threshold value (upper limit value).

  When the temperature difference between the inner and outer surfaces of the main steam stop valve 102 or the steam control valve 103 is large (S34: Yes), the control unit 114 controls the boiler vent valve 106 so as to close the boiler vent valve 106 (S36). Thereafter, the process proceeds to detection of the inner surface temperature and outer surface temperature of the main steam stop valve 102 (S31).

  On the other hand, when the difference between the inner and outer surface temperatures of the main steam stop valve 102 and the steam control valve 103 is not large (S34: No), the control unit 114 determines the inner surface temperature and the outer surface temperature of the main steam stop valve 102 and the steam control valve 103. It is determined whether or not the target temperature has been reached (S35).

  When the inner surface temperature and the outer surface temperature of the main steam stop valve 102 and the steam control valve 103 reach the target temperatures (S35: Yes), the forced cooling of the turbines 12 and 13 is terminated. On the other hand, when the inner surface temperature and the outer surface temperature of the main steam stop valve 102 and the steam control valve 103 do not reach the target temperatures (S35: No), detection of the inner surface temperature and the outer surface temperature of the main steam stop valve 102 (S31). Migrate to

  If the temperature difference between the inner and outer surfaces of the main steam stop valve 102 and the steam control valve 103 is large, the main steam stop valve 102 and the steam control valve 103 are rapidly cooled. Due to the rapid cooling, the main steam stop valve 102 and the steam control valve 103 may be damaged, and the life of the valves 102 and 103 may be shortened. On the other hand, according to the second modification, when the temperature difference between the inner and outer surfaces of the main steam stop valve 102 and the steam control valve 103 is large, the boiler vent valve 106 can be closed. In addition, the temperature difference between the inner and outer surfaces of the steam control valve 103 can be reduced. On the other hand, when the internal screen temperature difference between the main steam stop valve 102 and the steam control valve 103 is small, the boiler vent valve 106 can be opened, so that the turbines 12 and 13 can be forcibly cooled.

  Therefore, according to the second modification, forced cooling of the turbines 12 and 13 in consideration of the life of the main steam stop valve 102 and the steam control valve 103 can be realized with a simple configuration.

  Instead of controlling the flow rate of the outside air with the boiler vent valve 106 and the vacuum breaker valve 111, a regulating valve may be provided at the inlet of the condenser vacuum pump 105, and the flow rate of the outside air may be controlled with the regulating valve.

(Fifth embodiment)
Next, as a fifth embodiment, a specific configuration example that achieves both the recovery of drain from the main steam stop valve 102 and the steam control valve 103 and the cooling of the main steam stop valve 102 and the steam control valve 103 will be described. To do. Note that, in the description of the fifth embodiment, the same reference numerals are used for the components corresponding to the first and third embodiments, and redundant description is omitted. FIG. 11 is a conceptual diagram of the steam turbine cooling device 10 and the steam turbine cooling method showing the fifth embodiment.

  Similarly to recovering the drain generated in the turbines 12 and 13 to the condenser 15, it is desirable to recover the drain generated in the main steam stop valve 102 and the steam control valve 103 to the condenser 15. Therefore, as shown in FIG. 11, the third drain pipe 117 has a connection part 117 b connected to the condenser 15. The fourth drain pipe 119 also has a connection portion 119 b connected to the condenser 15.

  On the other hand, a part 117a of the third drain pipe 117 is branched at the connecting portion 117b and the branch point p7 and connected to the exhaust pipe 109 so that the main steam stop valve cooling flow path P_MSV can be formed. Further, a portion 119a of the fourth drain pipe 119 is branched at the connection portion 119b and the branch point p8 and connected to the exhaust pipe 109 so that the steam control valve cooling flow path P_CV can be formed. The part 117 a of the third drain pipe 117 and the part 119 a of the fourth drain pipe 119 may be part of the exhaust pipe 109.

  Further, a third stop valve 137 is disposed on the third drain pipe 117a between the branch point p7 and the exhaust pipe 109. A fourth stop valve 138 is disposed on the fourth drain pipe 119a between the branch point p8 and the exhaust pipe 109. Operations of the third stop valve 137 and the fourth stop valve 138 may be controlled by the control unit 114.

  When the steam turbine apparatus 1 of the fifth embodiment having the above configuration is normally operated, the control unit 114 closes both the third stop valve 137 and the fourth stop valve 138. Thereby, it is possible to prevent the drain generated in the main steam stop valve 102 and the steam control valve 103 from flowing into the condenser vacuum pump 105. On the other hand, when the high pressure turbine 12 is forcibly cooled, the control unit 114 opens both the third stop valve 137 and the fourth stop valve 138. Thereby, the main steam stop valve cooling flow path P_MSV and the steam control valve cooling flow path P_CV can be opened.

  According to the fifth embodiment, in response to opening and closing of the stop valves 137 and 138, the third drain pipe 117 and the fourth drain pipe 119 are connected to collect the drain from the main steam stop valve 102 and the steam control valve 103, This can be selectively used for cooling each of the valves 102 and 103. Therefore, the recovery of drain from the main steam stop valve 102 and the steam control valve 103 during normal operation and the cooling of the valves 102 and 103 during forced turbine cooling can be reliably achieved with a simple configuration.

  In the first to fifth embodiments, these may be combined as appropriate.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Steam turbine apparatus 10 Steam turbine cooling apparatus 12 High pressure turbine 13 Medium pressure turbine 15 Condenser 102 Main steam stop valve 103 Steam control valve 105 Condenser vacuum pump 106 Boiler vent valve 107 First drain pipe 109 Exhaust pipe 111 Vacuum break valve 112 Second drain piping 114 Control unit 117 Third drain piping 119 Fourth drain piping 151 Condenser water chamber P_H High pressure turbine cooling channel P_I Medium pressure turbine cooling channel P_MSV Main steam stop valve cooling channel P_CV Steam control valve cooling Flow path

Claims (10)

Stop the steam turbine on the turbine cooling flow path from the outside air valve to the condenser vacuum pump via the steam turbine and the condenser water chamber;
Aspirating outside air from the outside air valve through the turbine cooling flow path by the condenser vacuum pump,
The outside air sucked from the outside air valve is introduced into the steam turbine through the turbine cooling flow path by the condenser vacuum pump, and the steam turbine is cooled by the outside air introduced into the steam turbine,
The outside air discharged from the steam turbine is introduced into the condenser water chamber through the turbine cooling flow path by the condenser vacuum pump, and the outside air introduced into the condenser water chamber is introduced into the condenser water chamber. Cool,
A steam turbine cooling method in which outside air cooled by the condenser water chamber is sucked and discharged through the turbine cooling flow path by the condenser vacuum pump. Stopping the steam turbine includes stopping a high pressure turbine;
The suction of the outside air from the outside air valve through the turbine cooling channel is performed through the high pressure turbine cooling channel from the boiler vent valve to the condenser vacuum pump via the high pressure turbine and the condenser water chamber. Including suction of outside air through the boiler vent valve
2. The steam turbine cooling method according to claim 1, wherein the introduction of outside air sucked from the outside air valve into the steam turbine includes introduction of outside air sucked from the boiler vent valve into the high-pressure turbine. Stopping the steam turbine includes stopping the intermediate pressure turbine,
The suction of the outside air from the outside air valve through the turbine cooling channel is performed by cooling the intermediate pressure turbine from the vacuum breaker valve to the condenser vacuum pump via the intermediate pressure turbine and the condenser water chamber. Including suction of outside air from the vacuum breaker valve through a flow path,
The steam turbine cooling method according to claim 1 or 2, wherein the introduction of the outside air sucked from the outside air valve into the steam turbine includes introduction of the outside air sucked from the vacuum break valve into the intermediate pressure turbine.   When the outside air is sucked through the high-pressure turbine cooling channel, the high-pressure turbine is branched from the high-pressure turbine cooling channel at a branch point between the main steam stop valve and the steam control valve on the high-pressure turbine cooling channel, The main vacuum stop valve cooling passage that joins the high-pressure turbine cooling passage at the junction with the condenser water chamber sucks outside air from the boiler vent valve by the condenser vacuum pump, and The steam turbine cooling method according to claim 2, wherein the steam stop valve is cooled.   When sucking outside air through the high-pressure turbine cooling flow path, the high-pressure turbine and the condenser water chamber branch off from the high-pressure turbine cooling flow path at a branch point between the steam control valve and the high-pressure turbine. 5. The steam control valve is cooled by sucking outside air from the boiler vent valve by the condenser vacuum pump through a steam control valve cooling flow path that joins the high pressure turbine cooling flow path at a junction between the steam control valve and the steam control valve. The steam turbine cooling method according to claim 1.   The steam turbine cooling method according to any one of claims 1 to 5, wherein an opening degree of the outside air valve is controlled according to a metal temperature of the steam turbine. A high-pressure turbine cooling flow path from a boiler vent valve to a condenser vacuum pump via a high-pressure turbine and a condenser water chamber, the first steam pipe between the boiler vent valve and the high-pressure turbine; Connected downstream to a plurality of drain pipes including a first drain pipe downstream of the high-pressure turbine, the first drain pipe and a second drain pipe downstream of the intermediate pressure turbine, and the condenser water is connected to each drain pipe. A high-pressure turbine cooling flow path having an exhaust pipe leading to the condenser vacuum pump via a chamber;
An intermediate pressure turbine cooling flow path from a vacuum breaker valve to the condenser vacuum pump via the intermediate pressure turbine and the condenser water chamber, wherein the condenser, the low pressure turbine, and the low pressure turbine And an intermediate pressure turbine cooling flow path having a second steam pipe between the intermediate pressure turbine, the second drain pipe, and the exhaust pipe;
A steam turbine cooling device comprising:   Branching from the high-pressure turbine cooling flow path at a first branch point between the main steam stop valve and the steam control valve on the high-pressure turbine cooling flow path, and a junction between the high-pressure turbine and the condenser water chamber The main steam stop valve cooling comprising the first steam pipe, the third drain pipe connected to the first steam pipe at the first branch point, and the exhaust pipe. The steam turbine cooling device according to claim 7, comprising a flow path.   The high pressure turbine cooling flow path branches off from the high pressure turbine cooling flow path at a second branch point between the steam control valve and the high pressure turbine, and the high pressure turbine cooling flow path at a confluence point between the high pressure turbine and the condenser water chamber. And a steam control valve cooling passage having the first steam pipe, a fourth drain pipe connected to the first steam pipe at the second branch point, and the exhaust pipe. The steam turbine cooling device described.   The control part which performs control of the opening degree of the said boiler vent valve according to the metal temperature of the said high pressure turbine and / or control of the opening degree of the said vacuum breaker valve according to the metal temperature of the said intermediate pressure turbine is provided. The steam turbine cooling device according to claim 9.

Images