Steam turbine system

Abstract

Provided is a steam turbine system capable of discharging steam to the outside even when steam leakage occurs. 【Solution means】A main steam stop valve having a first valve body movable forward and backward along a first axis, a first valve seat capable of contacting the first valve body, and a first casing forming a first space for accommodating the first valve body and the first valve seat; a steam control valve having a second valve body movable forward and backward along a second axis, a second valve seat having a second seat surface capable of contacting the second valve body, and a second casing forming a second space for accommodating the second valve body and the second valve seat. A ventilator flow path communicating with an external condenser is formed in a connection flow path between the main steam stop valve and the steam control valve, and further includes a solenoid valve provided between the ventilator flow path and the condenser, and a control device for controlling the opening and closing state of the solenoid valve. The control device opens the solenoid valve when the main steam stop valve is in a closed state and the inside of the condenser is in a vacuum state.

Description

Technical Field

[0001] The present disclosure relates to a steam turbine system.

Background Art

[0002] In a steam turbine plant, a main steam stop valve (on-off valve) for switching the steam supply to the turbine and a steam control valve for controlling a fine steam flow rate are provided (see Patent Document 1 below). When viewed from the steam flow direction, the main steam stop valve is arranged on the upstream side, and the steam control valve is integrally provided immediately downstream thereof. When stopping the turbine, an operation is performed in which both of these two valves are closed to suppress the inflow of steam into the turbine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the main steam stop valve, misalignment may occur between the valve body and the valve seat, and there may be a case where complete closing cannot be achieved. Then, there has been a problem that steam flows in through the gap between the valve body and the valve seat and flows into the turbine through fine gaps formed in various parts of the steam control valve on the downstream side.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a steam turbine system capable of discharging steam to the outside without allowing the steam to flow into the turbine even when steam leakage occurs.

Means for Solving the Problems

[0006] To solve the above problems, the steam turbine system according to the present disclosure includes a main steam stop valve having a first valve body movable forward and backward along a first axis, a first valve seat capable of contacting the first valve body, and a first casing forming a first space for accommodating the first valve body and the first valve seat; a steam regulating valve having a second valve body movable forward and backward along a second axis, a second valve seat having a second seat surface capable of contacting the second valve body, and a second casing forming a second space for accommodating the second valve body and the second valve seat; and a connecting flow path connecting between the main steam stop valve and the steam regulating valve. A ventilator flow path communicating with an external condenser is formed in the connecting flow path, and further includes a solenoid valve provided between the ventilator flow path and the condenser, and a control device for controlling the opening and closing state of the solenoid valve. The control device opens the solenoid valve when the main steam stop valve is in a closed state and the inside of the condenser is in a vacuum state.

Advantages of the Invention

[0007] According to the present disclosure, it is possible to provide a steam turbine system that can surely apply the differential pressure before and after the main steam stop valve to maintain the closed state, and even if steam leakage occurs, the steam can be discharged to the outside without flowing into the turbine.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the valve device 10 according to the first embodiment of the present disclosure and the steam turbine system 1 including the same will be described with reference to FIGS. 1 to 5.

[0010] (Configuration of the steam turbine system 1) As shown in FIG. 1, this steam turbine system 1 includes a plurality (two in this example) of valve devices 10, a recovery flow path 11, a check valve 12, a solenoid valve 13, a condenser 14, a control device 15, and a ventilator flow path 16.

[0011] Although details will be described later, the valve device 10 is provided to control the supply amount of steam to a turbine (not shown). The valve device 10 is provided with a ventilator flow path 16 for discharging the steam (referred to as leakage steam) that has passed through the valve device 10 when the turbine is stopped, toward the condenser 14. A check valve 12 is provided on each ventilator flow path 16. This check valve 12 is provided so that the leakage steam does not flow backward through the ventilator flow path 16 toward the other valve device 10 when the leakage steam flows out from one valve device 10.

[0012] At the downstream end of the ventilator flow path 16, a recovery flow path 11 is connected. The downstream end of the recovery flow path 11 is connected to a condenser 14. The condenser 14 is a device for returning the low-temperature steam that has finished working in a turbine that works with the steam supplied from the valve device 10 to water and sending it back to the boiler again. During the operation of the turbine, the inside of the condenser 14 is in a vacuum state. Therefore, the leaked steam flowing in the recovery flow path 11 flows toward the condenser 14 due to the pressure difference. The leaked steam is sent to the condenser 14, returned to water in the same way as the steam recovered from other paths, and eventually sent to the boiler. Although not shown in detail, the condenser 14 is provided with a pressure sensor or a pressure gauge for detecting the internal pressure state. Information regarding this pressure is sent to a control device 15 described later as an electrical signal.

[0013] An electromagnetic valve 13 is provided on the recovery flow path 11. The electromagnetic valve 13 is provided to switch the open states of the recovery flow path 11 and the ventilator flow path 16. The opening and closing state of the electromagnetic valve 13 is controlled by the control device 15. The configuration and processing flow of the control device 15 will be described later.

[0014] (Configuration of the valve device 10) Next, the configuration of the valve device 10 will be described in detail with reference to FIGS. 2 and 3. As shown in FIG. 2, this valve device 10 includes a main steam stop valve 2 and a steam control valve 3. The main steam stop valve 2 is an on-off valve that switches the supply and stop of steam. The steam control valve 3 is an adjustment valve for more precisely controlling the steam flow rate supplied to the turbine when the main steam stop valve 2 is in the open state.

[0015] (Configuration of the main steam stop valve 2) The main steam stop valve 2 has a first casing 21, a first valve rod 22, a first drive unit 23, a bush 24, a first valve body 25, a first valve seat 26, a physical quantity acquisition unit 27, and a first opening / closing sensor 28.

[0016] The first valve rod 22, the first valve body 25, and the first valve seat 26 are accommodated in the first space 90 within the first casing 21. This first space 90 is a space for the first valve rod 22 and the first valve body 25 to move forward and backward, and is also a flow path for steam to flow. A supply flow path 91 communicating with the boiler is connected to the first space 90. Steam flows into the first space 90 through the supply flow path 91.

[0017] The first valve rod 22 is rod-shaped and extends along the first axis X extending in the horizontal direction. Here, the horizontal direction referred to means substantial horizontal, and a slight error is allowed. The first valve rod 22 is supported within the first casing 21 via a bush 24 provided between the first valve rod 22 and the first casing 21. The bush 24 is cylindrical with the first axis X as the center, and the first valve rod 22 is inserted inside it. The bush 24 has a large-diameter portion 41 and a small-diameter portion 42. The large-diameter portion 41 and the small-diameter portion 42 are integrally formed, and the large-diameter portion 41 is located on one side in the first axis X direction from the small-diameter portion 42. The large-diameter portion 41 is engaged with the step portion 92 of the first casing 21 from one side in the first axis X direction. A coil spring (not shown) is arranged on the end face on the other side in the first axis X direction of the small-diameter portion 42. The biasing force of this coil spring is received by the bush 24.

[0018] On the other side in the first axis X direction of the first valve rod 22, a first drive portion 23 is provided. The first drive portion 23 is, for example, an electric motor, and can apply a force in the first axis X direction to the first valve rod 22 to move the first valve rod 22 forward and backward.

[0019] At the end of the first valve rod 22 on one side in the direction of the first axis X (that is, the side where the steam control valve 3 is located when viewed from the main steam stop valve 2), a first valve body 25 is attached. The first valve body 25 has a valve body main body 51 and a small valve body 52. The small valve body 52 is integrally attached to the tip of the first valve rod 22. The small valve body 52 has a frustum shape centered on the first axis X by gradually increasing in diameter from one side to the other side in the direction of the first axis X. When the first valve rod 22 moves forward and backward in the direction of the first axis X, the small valve body 52 also moves forward and backward integrally.

[0020] The valve body main body 51 covers the first valve rod 22 and the small valve body 52 from the outer peripheral side. Specifically, the valve body main body 51 has a valve body tip portion 53 and a cylindrical portion 54. The valve body tip portion 53 has a frustum shape centered on the first axis X by gradually increasing in diameter from one side to the other side in the direction of the first axis X.

[0021] The surface of the valve body tip portion 53 facing one side in the direction of the first axis X is defined as a first contact surface S1. The first contact surface S1 can contact the first seat surface 61 of the first valve seat 26 described later. The surface of the valve body tip portion 53 facing the other side in the direction of the first axis X is defined as a second contact surface S2. A through hole 55 extending in the direction of the first axis X on the first axis X is formed between the second contact surface S2 and the first contact surface S1. This through hole 55 can be closed when the small valve body 52 contacts the second contact surface S2.

[0022] The cylindrical portion 54 is integrally provided on the other side of the valve body main body 51 in the direction of the first axis X. The cylindrical portion 54 has a cylindrical shape centered on the first axis X. The above small valve body 52 and the first valve rod 22 can move forward and backward in the space on the inner peripheral side of the cylindrical portion 54 in the direction of the first axis X.

[0023] Also, a locking portion 56 is provided at the end on the other side of the cylindrical portion 54 in the direction of the first axis X. The locking portion 56 has an annular shape centered on the first axis X, and a hole through which the first valve rod 22 is inserted is formed in the central portion thereof. When the first valve rod 22 is moved to the other side in the direction of the first axis X, initially the first valve rod 22 is displaced through this hole while the valve body main body 51 is in a stationary state. When the first valve rod 22 is further moved from this state, the small valve body 52 abuts against the locking portion 56, so that a load acting on the valve body main body 51 toward the other side in the direction of the first axis X is applied, and the valve body main body 51 is also displaced.

[0024] The first valve seat 26 is disposed on one side of the valve body main body 51 in the direction of the first axis X within the first space 90 of the first casing 21. The first valve seat 26 has a cylindrical shape centered on the first axis X. The first seat surface 61, which is the end surface on the other side of the first valve seat 26 in the direction of the first axis X, has a conical surface shape that gradually increases in diameter from one side to the other side in the direction of the first axis X. The first contact surface S1 of the valve body main body 51 can abut against the first seat surface 61, and in this case, the main steam stop valve 2 is in a closed state. On the other hand, in a state where the valve body main body 51 is separated from the first seat surface 61 (that is, in a state where the main steam stop valve 2 is open), the steam that has flowed into the first space 90 through the above-described supply passage 91 flows toward the downstream steam control valve 3 through the gap between the first seat surface 61 and the valve body main body 51. This steam passage between the main steam stop valve 2 and the steam control valve 3 is called a connection passage 70.

[0025] A ventilator passage 16 that extends through the inside and outside of the first casing 21 is formed in the connection passage 70. The downstream end of the ventilator passage 16 communicates with the condenser 14. Therefore, when the condenser 14 is operated and its interior is in a vacuum state, the negative pressure extends to the above-described connection passage 70 through the ventilator passage 16.

[0026] On the supply flow path 91 in the first casing 21, a physical quantity acquisition unit 27 is provided. The physical quantity acquisition unit 27 acquires various physical quantities including, for example, the temperature, pressure, or humidity in the supply flow path 91, and transmits them to a control device 15 described later as electrical signals. As the physical quantity acquisition unit 27, known temperature sensors, pressure gauges, humidity sensors, etc. are appropriately combined and used.

[0027] Also, in the first casing 21, a first opening / closing sensor 28 is provided that detects the open / closed state of the main steam stop valve 2 by detecting the advancing / retreating position of the first valve rod 22. As the first opening / closing sensor 28, for example, in addition to a microswitch, an element capable of detecting the position and displacement amount of the first valve rod 22 non - contact is used. The first opening / closing sensor 28 transmits the open / closed state of the steam control valve 3 to the control device 15 as an electrical signal.

[0028] (Configuration of the steam control valve 3) The steam control valve 3 includes a second casing 31, a second valve rod 32, a second drive unit 33, a second valve body 34, a second valve seat 35, and a second opening / closing sensor 36.

[0029] The second casing 31 is connected to one side in the direction of the first axis X of the first casing 21. The second valve rod 32, the second valve body 34, and the second valve seat 35 are housed in a second space 93 within the second casing 31. The second space 93 communicates with the first space 90 via the above - mentioned connection flow path 70. That is, when the main steam stop valve 2 and the steam control valve 3 are in the open state, this second space 93 functions as a steam flow path.

[0030] The second valve rod 32 is in the shape of a rod extending along the second axis Y. The second axis Y intersects (is orthogonal to) the first axis X and extends in the vertical direction. The second valve rod 32 can be advanced and retracted in the direction of the second axis Y by the second drive unit 33. As shown in FIG. 3, the second valve rod 32 has a valve rod main body 81 and a valve rod tip 82.

[0031] The valve rod body 81 is rod-shaped and extends along the second axis Y. A second drive part 33 is connected to the upper end of the valve rod body 81. A valve rod tip part 82 is provided at the lower end of the valve rod body 81. The valve rod tip part 82 is cylindrical with a diameter slightly larger than that of the valve rod body 81. An internal flow path 83 through which steam flows is formed inside the valve rod tip part 82. The internal flow path 83 extends in the direction of the second axis Y. The lower end of the internal flow path 83 is open. Further, a plurality of side holes 84 are formed at an intermediate position in the vertical direction of the valve rod tip part 82.

[0032] The second valve body 34 is cylindrical and covers the above-mentioned valve rod tip part 82 from the outer peripheral side. The second valve body 34 is supported so as to be movable forward and backward in the direction of the second axis Y with respect to the second valve rod 32. The lower edge on the inner peripheral surface of the second valve body 34 forms a conical surface by gradually increasing the diameter from bottom to top. This surface forms a third contact surface S3 that can contact the valve rod tip part 82.

[0033] Further, the lower edge on the outer peripheral surface of the second valve body 34 forms a conical surface by gradually increasing the diameter from bottom to top. This surface forms a fourth contact surface S4 that can contact the second seat surface 85 of the second valve seat 35 described later.

[0034] The second casing 31 is provided with a second opening / closing sensor 36 that detects the opening / closing state of the steam control valve 3 by detecting the forward / backward movement position of the second valve rod 32. As the second opening / closing sensor 36, similar to the first opening / closing sensor 28, in addition to a microswitch, an element capable of detecting the position and displacement amount of the first valve rod 22 non-contact is used. The second opening / closing sensor 36 transmits the opening / closing state of the steam control valve 3 to the control device 15 as an electrical signal.

[0035] (Configuration of the control device 15) Subsequently, with reference to FIG. 4, the configuration of the control device 15 will be described. As shown in the figure, the control device 15 includes an information acquisition unit 101, a determination unit 102, a drive unit 103, and a storage unit 104.

[0036] The information acquisition unit 101 acquires various information from the pressure sensor provided in the above-mentioned condenser 14, the physical quantity acquisition unit 27 provided in the supply flow path 91, the first on-off sensor 28 provided in the main steam stop valve 2, and the second on-off sensor 36 provided in the steam control valve 3. Specifically, this information includes the pressure state in the condenser 14, various physical quantities including the temperature, pressure, or humidity in the supply flow path 91, the on-off state of the main steam stop valve 2, and the on-off state of the steam control valve 3. These pieces of information acquired by the information acquisition unit 101 are temporarily stored in the storage unit 104.

[0037] The determination unit 102 determines whether or not the operation for stopping the turbine has been started by comparing the above various information with a predetermined threshold value. As an example, if the main steam stop valve 2 is in the closed state, it can be determined that the operation for stopping the turbine has started. The drive unit 103 generates and transmits an electrical signal for switching the on-off state of the solenoid valve 13 based on the determination result of the determination unit 102.

[0038] Next, with reference to FIG. 5, an example of the processing flow of the control device 15 will be described. First, in step S101, the information acquisition unit 101 acquires the open / closed state from the first on-off sensor 28 and the second on-off sensor 36. In the next steps S102 and S103, the information acquisition unit 101 also acquires the temperature and pressure in the supply flow path 91, respectively. In step S104, the determination unit 102 determines whether the main steam stop valve 2 is closed based on the information acquired in step S101. If it is determined Yes in step S104, then in the subsequent step S105, the determination unit 102 determines whether the inside of the condenser 14 is in a vacuum state. On the other hand, if it is determined No in step S104, the process returns to step S101 again. If it is determined Yes in step S105, then in the subsequent step S106, the determination unit 102 determines whether steam is flowing in the supply flow path 91. This determination is made comprehensively considering the various physical quantities described above. If it is determined No in step S105, the process returns to step S101 again. If it is determined Yes in step S106, then in step S107, the determination unit 102 determines whether the steam control valve 3 is closed. If it is determined Yes in step S107, the drive unit 103 transmits an electric signal for switching the solenoid valve 13 to the open state to the solenoid valve 13. As a result, when the solenoid valve 13 is opened, the leaked steam in the connection flow path 70 flows into the ventilator flow path 16. If it is determined No in step S107, the process returns to step S101 again. Thus, the processing flow of the control device 15 is completed.

[0039] (Function and Effect) Here, in the main steam stop valve 2, misalignment may occur between the valve body and the valve seat, and a situation may arise where complete closing cannot be achieved. Then, there is a problem that steam flows in through the gap between the valve body and the valve seat, and the steam flows into the turbine through the fine gaps formed in various parts of the downstream steam control valve 3.

[0040] More specifically, as shown by the arrow in FIG. 3, the steam that has leaked from the main steam stop valve 2 goes upward through the gap between the second valve body 34 and the second casing 31, then returns downward through the gap between the second valve body 34 and the second valve rod 32, and finally is discharged to the downstream side, that is, the turbine side, through the internal flow path 83 of the second valve rod 32. As a result, the turbine inadvertently starts to rotate. To solve this problem, the above-described configurations are adopted in the present embodiment.

[0041] According to the above configuration, even when, due to some external factor, the first valve body 25 of the main steam stop valve 2 is misaligned with respect to the first valve seat 26 and steam inflow from the first space 90 to the connection flow path 70 occurs, the steam can be returned to the condenser 14 through the ventilator flow path 16. In particular, when the main steam stop valve 2 is in the closed state and the inside of the condenser 14 is in a vacuum state, the control device 15 opens the solenoid valve 13 provided between the ventilator flow path 16 and the condenser 14. First, by making it one of the conditions that the main steam stop valve 2 appears to be in the closed state, the solenoid valve 13 is opened only when the turbine should be in a stopped state. Also, by making it another condition that the inside of the condenser 14 is in a vacuum state, in a state where the second space 93 communicating with the condenser 14 is in a vacuum state, the steam can be drawn into the ventilator flow path 16 by negative pressure from the second space 93. Thereby, it becomes possible to more reliably collect the leaked steam toward the condenser 14. Therefore, the operability of the steam turbine system 1 can be further improved.

[0042] According to the above configuration, even though it is necessary to stop the turbine, as an additional condition that steam is flowing in the first space 90, the control device 15 opens the solenoid valve 13. As a result, the steam is immediately recovered by the condenser 14 through the ventilator flow path 16. Therefore, the time required to stop the turbine can be significantly shortened. Also, it is possible to prevent the turbine from rotating inadvertently due to the leaked steam. Therefore, the operability of the steam turbine system 1 can be further improved. Furthermore, by making the conditions for opening the solenoid valve 13 stricter, it is possible to more carefully confirm and ensure that the turbine needs to be stopped. In other words, malfunction or runaway of the control device 15 when there is no request to stop the turbine can be avoided. Therefore, more stable operation of the steam turbine system 1 can be realized.

[0043] According to the above configuration, in addition to the main steam stop valve 2, as an additional condition that the steam control valve 3 is also in the closed state, the control device 15 opens the solenoid valve 13. As a result, after more carefully ensuring and confirming that the turbine needs to be stopped, the control device 15 can open the ventilator flow path 16. In other words, malfunction or runaway of the control device 15 when there is no request to stop the turbine can be avoided. Therefore, more stable operation of the steam turbine system 1 can be realized.

[0044] Here, when the first axis X of the main steam stop valve 2 extends in the horizontal direction, the first valve rod 22 and the first valve body 25 move forward and backward in the horizontal direction. In this case, since a downward load is applied to the first valve body 25 by gravity, misalignment between the first valve body 25 and the first valve seat 26 tends to occur easily. According to the above configuration, even when steam flows from the first space 90 to the second space 93 under such an environment and configuration where misalignment is likely to occur, it is possible to more actively return the steam to the condenser 14 through the ventilator flow path 16. Therefore, more stable operation of the steam turbine system 1 can be realized.

[0045] (Other Embodiments) As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included.

[0046] For example, as the first modification example and the second modification example of the processing flow of the control device 15, the flows shown in FIGS. 6 and 7 can also be adopted. In the example of FIG. 6, step S107 is omitted. In the example of FIG. 7, steps S106 and S107 are omitted. Even with this configuration, the same operational effects as those described above can be obtained.

[0047] Also, the number of valve devices 10 shown in FIG. 1 is an example, and it can be appropriately increased or decreased according to the number of turbines and boilers. In any case, the same operational effects as those described above can be obtained.

[0048] Note that, in the control device 15 in the embodiments of the present disclosure, the order of processing may be changed within the range where appropriate processing is performed.

[0049] Each of the storage unit 104 and other storage devices in the embodiments of the present disclosure may be provided anywhere within the range where appropriate information transmission and reception are performed. Also, each of the storage unit 104 and other storage devices may exist in a plurality and store data in a distributed manner within the range where appropriate information transmission and reception are performed.

[0050] The process of the processing by the control device 15 described above is stored in a computer-readable recording medium in the form of a program, and the above processing is performed by the computer 300 reading and executing this program. Specific examples of the computer 300 are shown below.

[0051] As shown in FIG. 8, the computer 300 includes a CPU 301, a main memory 302, a storage 303, and an interface 304. For example, the above-described control device 15 is implemented in a computer 300. The operations of each of the above-described processing units are stored in a storage 303 in the form of a program. The CPU 301 reads the program from the storage 303, expands it in the main memory 302, and executes the above processing according to the program. Further, the CPU 301 secures a storage area corresponding to the above-described storage unit 104 in the main memory 302 according to the program.

[0052] Examples of the storage 303 include an HDD (Hard Disk Drive), an SSD (Solid State Drive), a magnetic disk, a magneto-optical disk, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), a semiconductor memory, and the like. The storage 303 may be an internal medium directly connected to the bus of the computer 300, or may be an external medium connected to the computer 300 via an interface 304 or a communication line. Further, when this program is distributed to the computer 300 via a communication line, the computer 300 that has received the distribution may expand the program in the main memory 302 and execute the above processing. Note that the storage 303 is a non-transitory tangible storage medium.

[0053] Further, the above program may implement a part of the above-described functions. Furthermore, the above program may be a file that can be realized in combination with a program already recorded in the computer 300, that is, a so-called difference file (difference program).

[0054] In addition to or instead of the above configuration, a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device), an ASIC (Application Specific Integrated Circuit), a GPU (Graphics Processing Unit), and a processing device similar thereto may be provided. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor may be realized by the integrated circuit.

[0055] <Appendix> The steam turbine system 1 described in each embodiment can be understood as follows, for example.

[0056] (1) The steam turbine system 1 according to the first aspect includes a main steam stop valve 2 having a first valve body 25 that can move forward and backward along a first axis X, a first valve seat 26 that can contact the first valve body 25, and a first casing 21 that forms a first space 90 for accommodating the first valve body 25 and the first valve seat 26; a steam control valve 3 having a second valve body 34 that can move forward and backward along a second axis Y, a second valve seat 35 having a second seat surface 85 that can contact the second valve body 34, and a second casing 31 that forms a second space 93 for accommodating the second valve body 34 and the second valve seat 35; and a connection flow path 70 that connects between the main steam stop valve 2 and the steam control valve 3. A ventilator flow path 16 that communicates with an external condenser 14 is formed in the connection flow path 70, and further includes a solenoid valve 13 provided between the ventilator flow path 16 and the condenser 14, and a control device 15 that controls the opening and closing state of the solenoid valve 13. The control device 15 opens the solenoid valve 13 when the main steam stop valve 2 is in a closed state and the inside of the condenser 14 is in a vacuum state.

[0057] According to the above configuration, even when the first valve body 25 of the main steam stop valve 2 is misaligned with respect to the first valve seat 26 and steam flows from the first space 90 into the connecting flow path 70, the steam can be returned to the condenser 14 through the ventilator flow path 16.

[0058] (2) The steam turbine system 1 according to the second aspect is the steam turbine system 1 of (1), wherein when steam is flowing in the first space 90, the control device 15 further opens the electromagnetic valve 13.

[0059] According to the above configuration, the time required for turbine shutdown can be significantly shortened.

[0060] (3) The steam turbine system 1 according to the third aspect is the steam turbine system 1 of (1) or (2), wherein when the steam control valve 3 is in the closed state, the control device 15 further opens the electromagnetic valve 13.

[0061] According to the above configuration, after more carefully ensuring and confirming that the turbine needs to be stopped, the control device 15 can open the ventilator flow path 16.

[0062] (4) The steam turbine system 1 according to the fourth aspect is the steam turbine system 1 according to any one of the aspects (1) to (3), wherein the first axis X of the main steam stop valve 2 extends in the horizontal direction.

[0063] According to the above configuration, even when steam flows from the first space 90 into the second space 93 under an environment and configuration where misalignment is likely to occur, the steam can be more actively returned to the condenser 14 through the ventilator flow path 16.

Explanation of Reference Numerals

[0064] 1... Steam turbine system 2... Main steam stop valve 3... Steam control valve 10... Valve device 11... Recovery flow path 12... Check valve 13... Solenoid valve 14... Condenser 15... Control device 16... Ventilator flow path 21... First casing 22... First valve rod 23... First drive unit 24... Bush 25... First valve body 26... First valve seat 27... Physical quantity acquisition unit 28... First opening / closing sensor 31... Second casing 32... Second valve rod 33... Second drive unit 34... Second valve body 35... Second valve seat 36... Second opening / closing sensor 41... Large diameter part 42... Small diameter part 51... Valve body main body 52... Small valve body 53... Valve body tip part 54... Cylindrical part 55... Through hole 56... Locking part 61... First seat surface 70... Connection flow path 81... Valve rod main body 82... Valve rod tip part 83... Internal flow path 84... Side hole 85... Second seat surface 90... First space 91... Supply flow path 92... Step part 93... Second space 101... Information acquisition unit 102... Judgment unit 103... Drive unit 104... Memory unit 300... Computer 301... CPU 302... Main memory 303... Storage 304... Interface S1... First contact surface S2... Second contact surface S3... Third contact surface S4... Fourth contact surface X... First axis Y... Second axis

Claims

1. A main steam stop valve having a first valve body that can move forward and backward along a first axis, a first valve seat that can abut against the first valve body, and a first casing that forms a first space for accommodating the first valve body and the first valve seat; A steam control valve having a second valve body that can move forward and backward along a second axis, a second valve seat having a second seat surface that can abut against the second valve body, and a second casing that forms a second space for accommodating the second valve body and the second valve seat; A connecting flow path connecting between the main steam stop valve and the steam control valve; Comprising; A ventilator flow path communicating with an external condenser is formed in the connecting flow path; A solenoid valve provided between the ventilator flow path and the condenser; A control device for controlling the open / closed state of the solenoid valve; Further comprising; The control device is; A steam turbine system that opens the solenoid valve when the main steam stop valve is in a closed state and the inside of the condenser is in a vacuum state.

2. The steam turbine system according to claim 1, wherein the control device further opens the solenoid valve when steam is flowing in the first space.

3. The steam turbine system according to claim 1 or 2, wherein the control device further opens the solenoid valve when the steam control valve is in a closed state.

4. The steam turbine system according to claim 1 or 2, wherein the first axis of the main steam stop valve extends in the horizontal direction.

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