Wastewater discharge monitoring device

Abstract

A wastewater discharge monitoring device is used in a steam turbine to monitor wastewater discharge caused by sucking fluid from the outside of the stationary blade into the internal space through a slit formed on the surface of at least one hollow stationary blade including an internal space, and comprises: a gas-liquid separation device that separates the fluid sucked into the internal space into a liquid phase and a gas phase; a liquid phase flow rate measuring device that measures the flow rate of the liquid phase separated by the gas-liquid separation device; a gas phase flow rate measuring device that measures the flow rate of the gas phase separated by the gas-liquid separation device; a liquid phase reflux line that connects the liquid phase flow rate measuring device with the steam turbine; and a gas phase reflux line that connects the gas phase flow rate measuring device with the steam turbine.

Description

Technical Field

[0001] The present disclosure relates to a wastewater discharge monitoring device.

[0002] This application claims priority based on Japanese Patent Application No. 2020-87905 filed with the Japan Patent Office on May 20, 2020, and the contents of which are incorporated herein by reference. Background Art

[0003] In a steam turbine, the rotor blades may be corroded and damaged by the collision of water droplets with the rotor blades. Patent document 1 discloses a steam turbine in which a slit is formed on the blade surface of a hollow stator blade to connect the internal space inside the stator blade with the outside of the stator blade, and water (liquid phase) attached to the surface of the stator blade is sucked into the internal space through the slit by the pressure difference, thereby enabling wastewater discharge. In this steam turbine, wastewater discharge is performed by adjusting the pressure difference between the outside and the internal space of the stator blade to an appropriate pressure difference corresponding to the turbine load fluctuation.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 62-157206 Summary of the invention

[0007] -Problems to be solved by the invention-

[0008] However, since not only the liquid phase but also the gas phase is sucked into the internal space through the slit, it is not actually known whether the wastewater is properly discharged. In order to understand whether the wastewater is properly discharged, it is necessary to measure the flow rates of both the liquid phase and the gas phase sucked into the internal space through the slit.

[0009] In view of the above circumstances, an object of at least one embodiment of the present disclosure is to provide a wastewater discharge monitoring device that can determine whether wastewater discharge is performed appropriately.

[0010] -Methods for solving problems-

[0011] In order to achieve the above-mentioned purpose, the wastewater discharge monitoring device involved in the present disclosure is used in a steam turbine to monitor wastewater discharge caused by sucking fluid from the outside of the stationary blade into the internal space through a slit formed on the surface of at least one hollow stationary blade including an internal space, and the wastewater discharge monitoring device comprises: a gas-liquid separation device that separates the fluid sucked into the internal space into a liquid phase and a gas phase; a liquid phase flow rate measuring device that measures the flow rate of the liquid phase separated by the gas-liquid separation device; a gas phase flow rate measuring device that measures the flow rate of the gas phase separated by the gas-liquid separation device; a liquid phase reflux line that connects the liquid phase flow rate measuring device with the steam turbine; and a gas phase reflux line that connects the gas phase flow rate measuring device with the steam turbine.

[0012] -Effects of the Invention-

[0013] According to the wastewater discharge monitoring device of the present disclosure, since the flow rates of both the liquid phase and the gas phase in the fluid sucked into the internal space of the stator blade through the slit formed in the stator blade of the steam turbine are measured, it is possible to understand whether the wastewater is discharged appropriately. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the wastewater discharge monitoring device involved in the first embodiment of the present disclosure.

[0015] Figure 2 This is a diagram showing a comparison between a case where an orifice nozzle is used and a case where a Laval nozzle is used as a critical nozzle used in the gas phase flow rate measuring device of the wastewater discharge monitoring device according to the first embodiment of the present disclosure.

[0016] Figure 3 This is a block diagram showing a preferred configuration of a wastewater discharge monitoring device for diagnosing abnormality of wastewater discharge based on flow rates of liquid and gas phases in the wastewater discharge monitoring device according to Embodiment 1 of the present disclosure.

[0017] Figure 4 This is a graph showing an example of abnormality detection of wastewater discharge.

[0018] Figure 5 This is a graph showing an example of abnormality detection of wastewater discharge.

[0019] Figure 6 This is a graph showing an example of abnormality detection of wastewater discharge.

[0020] Figure 7 It is a schematic diagram of the structure of the wastewater discharge monitoring device involved in the embodiment 2 of the present disclosure.

[0021] Figure 8It is a schematic diagram of the structure of the wastewater discharge monitoring device involved in the third embodiment of the present disclosure.

[0022] Fig. 9 It is a schematic diagram of the structure of the wastewater discharge monitoring device involved in the fourth embodiment of the present disclosure.

[0023] Fig.10 It is a schematic diagram of the structure of the wastewater discharge monitoring device involved in the fifth embodiment of the present disclosure.

[0024] Fig.11 This is a graph schematically showing the relationship between the pressure ratio and the flow rate in a gas phase flow rate measurement device having only one measurement mechanism.

[0025] Fig.12 This is a graph schematically showing the relationship between the pressure ratio and the flow rate in a gas phase flow rate measurement device having a plurality of measurement mechanisms. DETAILED DESCRIPTION

[0026] Hereinafter, a wastewater discharge monitoring device according to an embodiment of the present disclosure will be described based on the drawings. This embodiment represents one mode of the present disclosure and does not limit the present disclosure, and can be arbitrarily changed within the scope of the technical concept of the present disclosure.

[0027] (Implementation Method 1)

[0028] <Structure of wastewater discharge monitoring device according to embodiment 1 of the present disclosure>

[0029] like Figure 1 As shown, the wastewater discharge monitoring device 10 according to the first embodiment is used in a steam turbine 1 to monitor wastewater discharge caused by sucking fluid outside the stationary blade 2 into the internal space 3 through a slit 4 formed on the surface of at least one stationary blade 2 having a hollow shape including an internal space 3. The diaphragm 5 connecting the stationary blades 2 is configured to be hollow including an internal space 6, and the internal space 6 and the internal space 3 are connected to each other. In addition, although Figure 1 Although not shown in the figure, the steam turbine 1 includes a turbine including stator blades 2, a turbine outlet exhaust chamber, and a condenser chamber.

[0030] The wastewater discharge monitoring device 10 comprises: a gas-liquid separation device 11 for separating a fluid including a liquid phase and a gas phase into a liquid phase and a gas phase; a liquid phase flow rate measuring device 12 for measuring the flow rate of the liquid phase separated by the gas-liquid separation device 11; a gas phase flow rate measuring device 13 for measuring the flow rate of the gas phase separated by the gas-liquid separation device 11; a liquid phase reflux line 14 for connecting the liquid phase flow rate measuring device 12 to the steam turbine 1; and a gas phase reflux line 15 for connecting the gas phase flow rate measuring device 13 to the steam turbine 1.

[0031] The wastewater discharge monitoring device 10 further includes a two-phase flow passage 16 that connects the internal space 6 in the diaphragm 5 with the gas-liquid separation device 11. Since the internal space 6 and the internal space 3 are connected to each other, the two-phase flow passage 16 connects the internal space 3 with the gas-liquid separation device 11 via the internal space 6. In addition, the wastewater discharge monitoring device 10 further includes a gas phase flow passage 17 that connects the gas-liquid separation device 11 with the gas phase flow rate measuring device 13.

[0032] The structure of the gas-liquid separation device 11 is not particularly limited, and a cyclone separator of a demister type, a corrugated plate type, or a cyclone type based on a mesh or the like can be used. Among them, compared with a structure of a mesh or the like, a cyclone type structure can maintain a low pressure loss and a higher performance gas-liquid separation flow rate range, and can follow changes in measurement conditions or expand the control range, so as the gas-liquid separation device 11, a cyclone separator is preferably used.

[0033] The structure of the liquid phase flow rate measuring device 12 is not particularly limited, and a measuring device of any structure can be used. As an example of the liquid phase flow rate measuring device 12, a device including the following components can be used: a tank body 21 that stores the liquid phase separated by the gas-liquid separation device 11; and a liquid phase quantity detection unit 22 that detects the amount of the liquid phase in the tank body 21. As the liquid phase quantity detection unit 22, a liquid level meter that detects the liquid level of the liquid phase in the tank body 21 can be used. As the liquid level meter, a floating point type liquid level meter or a liquid level meter that detects the liquid level by light, infrared rays, ultrasonic waves, etc. can be used.

[0034] When the liquid phase flow rate measuring device 12 has a structure including a tank body 21, it is preferable that the end of the liquid phase reflux line 14 is connected to the bottom of the tank body 21. In addition, in this case, a drain valve 23 that can be automatically opened and closed according to the detection value of the liquid phase amount detection unit 22 may be provided in the liquid phase reflux line 14. For example, an upper limit value is set in advance for the detection value of the liquid phase amount detection unit 22, and the drain valve 23 can be opened after the detection value of the liquid phase amount detection unit 22 reaches the upper limit value.

[0035] The structure of the gas phase flow rate measuring device 13 is not particularly limited, and a measuring device of any structure can be used. As an example of the gas phase flow rate measuring device 13, a plurality of measuring mechanisms 30 are provided, and each of the measuring mechanisms 30 can use a mechanism including the following components: a pressure measuring device 31 for measuring the pressure of the gas phase; a critical nozzle 32 provided on the downstream side of the pressure measuring device 31; and an on-off valve 33 provided on the downstream side of the critical nozzle 32. As the critical nozzle 32, any nozzle such as an orifice nozzle or a Laval nozzle can be used, but for the reasons described below, it is preferable to use a Laval nozzle.

[0036] exist Figure 1In the embodiment, the gas phase flow rate measuring device 13 includes six measuring mechanisms 30, but the number is not limited to six, and the device may include only one measuring mechanism 30, or may include any number of measuring mechanisms 30 other than six. Each measuring mechanism 30 includes a gas phase flow pipe 34 through which the gas phase flows, but the inner diameters of the gas phase flow pipes 34 may be all the same or all different, and the inner diameters of some gas phase flow pipes 34 may be the same while the inner diameters of others may be different.

[0037] <Operation of Wastewater Discharge Monitoring Device According to Embodiment 1 of the Present Disclosure>

[0038] Next, the operation of the wastewater discharge monitoring device 10 according to the first embodiment of the present disclosure will be described. During the operation of the steam turbine 1, a fluid is sucked into the internal space 3 through the slit 4. Here, the sucked fluid includes liquid water, which is a liquid phase attached to the surface of the stationary blade 2, or a gas phase and a liquid phase in the steam, which is a working fluid of the steam turbine 1 passing through the stationary blade 2. The fluid sucked into the internal space 3 flows into the two-phase flow path 16 through the internal space 6 and flows in the two-phase flow path 16.

[0039] The fluid flowing through the two-phase flow path 16 flows into the gas-liquid separation device 11 and is separated into a liquid phase and a gas phase. The liquid phase, i.e., liquid water, flows into the tank portion 21 of the liquid phase flow rate measuring device 12 and is stored. On the other hand, the gas phase flows through the gas phase flow path 17 and flows into the gas phase flow rate measuring device 13.

[0040] In the liquid phase flow rate measuring device 12, the liquid phase amount detection unit 22 detects the change in the water level of the water in the tank body 21. Since the amount of water in the tank body 21 can be calculated based on the water level of the water in the tank body 21, the change in the flow rate of the liquid phase in the fluid sucked into the internal space 3 can be obtained based on the detection value of the liquid phase amount detection unit 22.

[0041] When the water level in the tank body 21 reaches the upper limit, the drain valve 23 is opened, and the water in the tank body 21 is discharged from the tank body 21 and flows into the steam turbine 1, specifically, into the condenser (not shown) through the liquid phase reflux line 14. In this way, since the liquid phase can be automatically discharged from the tank body 21, long-term monitoring can be performed.

[0042] On the other hand, in the gas phase flow measurement device 13, the gas phase flows into at least one measuring mechanism 30. In the case where the gas phase flow measurement device 13 has a plurality of measuring mechanisms 30, by opening and closing the on-off valves 33 of the respective measuring mechanisms 30, the number of measuring mechanisms 30 into which the gas phase flows can be adjusted, thereby adjusting the pressure difference between the upstream and downstream of the slit 4 and the flow rate of the two-phase flow sucked into the internal space 3 through the slit 4, the details of which will be described in Embodiment 5 described later.

[0043] After the pressure of the gas phase flowing into the measuring mechanism 30 is measured by the pressure detector 31, it flows into the critical nozzle 32. The gas phase flowing into the critical nozzle 32 flows out of the critical nozzle 32 while expanding the flow path area again after reducing the flow path area. By using the critical nozzle 32 in the gas phase flow rate measuring device 13, the flow rate of the gas phase can be measured only by the pressure on the upstream side of the critical nozzle 32.

[0044] Figure 2 This shows a comparison of the pressure changes in the critical nozzle 32 when an orifice nozzle is used as the critical nozzle 32 and when a Laval nozzle is used. The pressure P1 at the position L1 before the flow path area is reduced in the critical nozzle 32 is the pressure measured by the pressure detector 31 (refer to Figure 1 ), and it is the same for any nozzle. Regarding the pressure at the position L2 after reducing the flow path area in the critical nozzle 32, it is set as P2 in the case of the Laval nozzle and P2' in the case of the orifice nozzle, then P2 < P2'. The pressure P3 at a sufficiently downstream position L3 is the same for any nozzle.

[0045] As long as the pressure ratio P1 / P3 is large enough, the pressure ratios P1 / P2 and P1 / P2' can reach the critical pressure ratio, so the flow rate of the gas phase can be calculated based on the measurement value of the pressure detector 31. However, if the pressure on the downstream side of the gas phase flow rate measuring device 13, that is, the pressure P3, rises due to the operating conditions of the steam turbine 1, sometimes the critical pressure ratio cannot be achieved in the critical nozzle 32. In contrast, according to the relationship of P2 < P2', by using a Laval nozzle as the critical nozzle 32, the possibility of reaching the critical pressure ratio can be increased, so the reliability of the gas phase flow rate measurement can be improved. Therefore, it is preferable to use a Laval nozzle as the critical nozzle 32.

[0046] In this way, in the wastewater discharge monitoring device 10 according to the first embodiment of the present disclosure, since the flow rates of both the liquid phase and the gas phase in the fluid sucked into the internal space 3 inside the stationary blade 2 of the steam turbine 1 through the slit 4 formed in the stationary blade 2 are measured, it is possible to determine whether the wastewater discharge is properly performed.

[0047] <Regarding the abnormal diagnosis of wastewater discharge>

[0048] Next, an example of diagnosing an abnormality in wastewater discharge based on the flow rates of the liquid phase and the gas phase measured by the liquid phase flow rate measuring device 12 and the gas phase flow rate measuring device 13 respectively will be described. For such a diagnosis, as Figure 3 shown, the wastewater discharge monitoring device 10 preferably includes a control device 20 electrically connected to the liquid phase flow rate measuring device 12 and the gas phase flow rate measuring device 13 respectively.

[0049] The flow rate of the liquid phase and the flow rate of the gas phase measured by the liquid phase flow rate measuring device 12 and the gas phase flow rate measuring device 13 are transmitted to the control device 20. The upper limit value and the lower limit value related to the flow rate of the liquid phase and the upper limit value and the lower limit value related to the flow rate of the gas phase are pre-set in the control device 20, and the control device 20 detects the abnormality of the wastewater discharge based on the transmitted flow rates of the liquid phase and the gas phase and the upper limit value and the lower limit value related to the flow rates of the liquid phase and the gas phase. As long as the flow rate of the liquid phase and the flow rate of the gas phase are respectively shifted between their respective upper limit values ​​and lower limit values, the control device 20 determines that the wastewater discharge is appropriately performed.

[0050] For example Figure 4 As shown, when the flow rate of the gas phase may decrease and fall below the lower limit value even though the flow rate of the liquid phase changes between the upper limit value and the lower limit value, the control device 20 (see Figure 3 ) is judged to be sucked into the stationary blade 2 (refer to Figure 1 ) of the internal space through the slit 4 (refer to Figure 1 ) produces an abnormality of reverse injection. If such an abnormality occurs, the risk of erosion damage increases. When such an abnormality is detected, the control device 20 operates the on-off valve 33 (refer to Figure 1 ) and increase the pressure ratio between the upstream and downstream of the slit 4, thereby increasing the flow rate of the gas phase. If such control is performed, the flow rate of the gas phase increases and moves between the upper limit and the lower limit, and wastewater is discharged appropriately.

[0051] For example Figure 5 As shown, when the flow rate of the gas phase may increase and exceed the upper limit value even though the flow rate of the liquid phase changes between the upper limit value and the lower limit value, the control device 20 (see Figure 3 ) is judged to exist slit 4 (refer to Figure 1 ) may increase the gas path due to deformation, etc. If left in this state, the output of the steam turbine 1 (see Figure 1) will decrease. When such an abnormality is detected, the control device 20 operates the on-off valve 33 (see Figure 1) within the range where the flow rate of the liquid phase does not change. Figure 1 ) to reduce the pressure ratio between the upstream and downstream of the slit 4. If such control is performed, the flow rate of the gas phase is reduced and moves between the upper limit and the lower limit, and wastewater discharge is appropriately performed.

[0052] For example Figure 6 As shown, when the flow rate of the gas phase changes between the upper limit and the lower limit, the flow rate of the liquid phase may increase and exceed the upper limit, the control device 20 (see Figure 3) It is determined that there is a possibility of an increase in the humidity of the main steam. In such a state, the risk of erosion damage also increases. Among them, since such an abnormality cannot be restored by control, by knowing the abnormality in advance, it is possible to prevent failures such as early regular inspections.

[0053] In this way, the control device 20 can automatically detect the occurrence of abnormality in wastewater discharge and the cause thereof.

[0054] In embodiment 1, it can also be configured that, when the wastewater discharge monitoring device 10 is equipped with a control device 20, an upper limit value related to the detection value of the liquid phase quantity detection unit 22 is set in advance in the control device 20, and when the detection value of the liquid phase quantity detection unit 22 reaches the upper limit value, the control device 20 opens the drain valve 23.

[0055] (Implementation Method 2)

[0056] Next, the wastewater discharge monitoring device according to Embodiment 2 is described. Compared with Embodiment 1, the wastewater discharge monitoring device according to Embodiment 2 is provided with a bypass line that connects the two-phase flow line 16 with the gas phase reflux line 15. In Embodiment 2, the same reference numerals are given to the same components as those of Embodiment 1, and their detailed description is omitted.

[0057] like Figure 7 As shown, the wastewater discharge monitoring device 10 according to the second embodiment of the present disclosure includes a bypass line 40 that connects the two-phase flow circulation line 16 with the gas phase reflux line 15. An on-off valve 41 is provided on the bypass line 40, and an on-off valve 18 is provided on the two-phase flow circulation line 16 at a position further downstream than the connection position with the bypass line 40. The other structures are the same as those of the first embodiment.

[0058] In the second embodiment, when measuring the flow rates of the liquid phase and the gas phase, the on-off valve 18 is opened and the on-off valve 41 is closed. On the other hand, when there is no need to measure the flow rates of the liquid phase and the gas phase, the on-off valve 18 is closed and the on-off valve 41 is opened, so that the fluid sucked into the internal space 3 can be returned to the steam turbine 1 via the bypass line 40 and the gas phase return line 15, thereby reducing the power consumption for flow rate measurement. In addition, it is also possible to perform maintenance of the liquid phase flow rate measuring device and the gas phase flow rate measuring device while continuing the operation of the steam turbine 1.

[0059] (Implementation 3)

[0060] Next, the wastewater discharge monitoring device involved in Embodiment 3 is described. The wastewater discharge monitoring device involved in Embodiment 3 is added with respect to Embodiment 1 or 2, and a first connecting line that connects the tank body 21 with the gas phase reflux line 15 is added. Hereinafter, Embodiment 3 is described by adding a first connecting line to the structure of Embodiment 2, but Embodiment 3 can also be configured by adding a first connecting line to the structure of Embodiment 1. In addition, in Embodiment 3, the same reference numerals are marked for the same components as those of Embodiment 2, and their detailed descriptions are omitted.

[0061] like Figure 8 As shown, the wastewater discharge monitoring device 10 according to the third embodiment of the present disclosure includes a first communication path 50 that connects the tank 21 and the gas phase reflux path 15. The first communication path 50 is provided with an on-off valve 51. The other structures are the same as those of the second embodiment.

[0062] According to the pressure difference between the gas-liquid separation device 11 and the tank body 21, the liquid phase separated by the gas-liquid separation device 11 is transferred to the tank body 21, but if the pressure difference is small, it is difficult for the liquid phase to transfer to the tank body 21. In contrast, in Embodiment 3, if the on-off valve 51 is opened, the pressure in the tank body 21 can be equalized to the pressure on the downstream side of the gas phase flow rate measuring device 13 via the first communication line 50, so that the pressure difference can be increased. As a result, the transfer of the liquid phase from the gas-liquid separation device 11 to the tank body 21 can be promoted, and the reliability of the flow rate measurement of the liquid phase can be improved.

[0063] (Implementation 4)

[0064] Next, a wastewater discharge monitoring device according to Embodiment 4 is described. Compared with Embodiment 3, the wastewater discharge monitoring device according to Embodiment 4 adds a second communication line that connects the gas phase flow line 17 with the first communication line 50. In Embodiment 4, the same reference numerals are given to the same components as those of Embodiment 3, and their detailed descriptions are omitted.

[0065] like Fig. 9 As shown, the wastewater discharge monitoring device 10 according to the fourth embodiment of the present disclosure includes a second communication path 60 that connects the gas phase flow path 17 and the first communication path 50. The second communication path 60 is provided with an on-off valve 61. The other structures are the same as those of the third embodiment.

[0066] In the fourth embodiment, when the on-off valve 61 is opened, the liquid phase accumulated in the gas phase flow path 17 can be transferred to the tank portion 21 via the second communication path 60 , thereby improving the reliability of the gas phase flow rate measurement.

[0067] (Implementation method 5)

[0068] Next, the wastewater discharge monitoring device according to the fifth embodiment will be described. The wastewater discharge monitoring device according to the fifth embodiment has a plurality of stationary blades 2 as the measurement object, relative to any one of the first to fourth embodiments. Hereinafter, the fifth embodiment will be described by setting a plurality of stationary blades 2 as the measurement object in the structure of the first embodiment, but the fifth embodiment may be configured by setting a plurality of stationary blades 2 as the measurement object in any one of the structures of the second to fourth embodiments. In addition, in the fifth embodiment, the same reference numerals are given to the same components as those of the first embodiment, and their detailed descriptions are omitted.

[0069] <Structure of wastewater discharge monitoring device according to Embodiment 5 of the present disclosure>

[0070] like Fig.10 As shown, in the wastewater discharge monitoring device 10 involved in the fifth embodiment of the present disclosure, the upstream end of the two-phase flow circulation line 16 is branched into four branch pipes 16a, 16b, 16c, and 16d, and each branch pipe is provided with an on-off valve 71a, 71b, 71c, and 71d. An on-off valve 18 is provided in the two-phase flow circulation line 16. The branch pipes 16a, 16b, 16c, and 16d are connected to the diaphragms 5a, 5b, 5c, and 5d so as to communicate with the internal spaces 6a, 6b, 6c, and 6d formed by the diaphragms 5a, 5b, 5c, and 5d connected to the four different stationary blades 2a, 2b, 2c, and 2d. The internal spaces 3a, 3b, 3c, 3d of the stationary blades 2a, 2b, 2c, 2d are connected to the internal spaces 6a, 6b, 6c, 6d, so the two-phase flow passage 16 connects the internal spaces 3a, 3b, 3c, 3d to the gas-liquid separation device 11 via the internal spaces 6a, 6b, 6c, 6d and the branch pipes 16a, 16b, 16c, 16d. In addition, the structure in which the upstream end of the flow passage 16 branches into four branch pipes is only an example, and it may also be a structure in which the upstream end of the flow passage 16 branches into two or three, or even five or more branch pipes. The other structures are the same as those in the first embodiment.

[0071] <Operation of the Wastewater Discharge Monitoring Device According to Embodiment 5 of the Present Disclosure>

[0072] In the fifth embodiment, the gas phase flow rate measuring device 13 includes six measuring mechanisms 30a, 30b, 30c, 30d, 30e, and 30f. When the inner diameters of the gas phase flow pipes 34a, 34b, 34c, 34d, 34e, and 34f of the respective measuring mechanisms are different, the flow rate of the two-phase flow sucked from the slits 4a, 4b, 4c, and 4d of the respective stationary blades and the pressure ratio between the upstream and downstream of the slits 4a, 4b, 4c, and 4d of the respective stationary blades can be independently adjusted by the combination of the open and closed states of the opening and closing valves 33a, 33b, 33c, 33d, 33e, and 33f of the respective measuring mechanisms (circles are marked for the opening and closing valves in Table 1). In addition, in Table 1, it is assumed that the inner diameters of the gas phase flow pipes 34a, 34b, 34c, 34d, 34e, and 34f are different from each other, and the inner diameters are successively larger.

[0073] [Table 1]

[0074]

[0075] For example, in a gas phase flow rate measuring device 13 having only one measuring mechanism, Fig.11 As shown in FIG. 1 , when the gas phase flow rate is reduced by changing the measurement object from the stationary blade 2a to the stationary blade 2b, the relationship between the pressure ratio and the flow rate is fixed to 1 point, and the flow rate measurement at an appropriate pressure ratio may not be performed. In contrast, in the gas phase flow rate measurement device 13 having a plurality of measurement mechanisms, the combination of the open and close states of the on-off valves 33a, 33b, 33c, 33d, 33e, and 33f, for example, Fig.12 As shown, it is possible to realize the adjustment of the flow rate and the pressure ratio independently of each other, that is, the flow rate can be changed even at the same pressure ratio, and wastewater can be discharged under appropriate conditions.

[0076] In the fifth embodiment, a plurality of physically independent stationary blades 2a to 2d are used as an example to explain a plurality of measurement objects, but the present invention is not limited to this embodiment. The fifth embodiment assumes that even if it is a same stationary blade, the measurement period is different, that is, a plurality of measurements for a same stationary blade are also set as a plurality of measurement objects. In addition, in such a case, it is not necessary to branch the upstream end of the two-phase flow flow path 16 into a plurality of branch pipes, and the same structure as the first embodiment can also be used.

[0077] The contents described in each of the above-mentioned embodiments can be understood, for example, as follows.

[0078] [1] A wastewater discharge monitoring device according to one embodiment is used in a steam turbine (1) to monitor wastewater discharge caused by sucking fluid outside the stator blade (2) into the internal space (3) through a slit (4) formed on the surface of at least one hollow stator blade (2) including an internal space (3),

[0079] The wastewater discharge monitoring device (10) comprises:

[0080] a gas-liquid separation device (11) for separating the fluid sucked into the internal space (3) into a liquid phase and a gas phase;

[0081] a liquid phase flow rate measuring device (12) for measuring the flow rate of the liquid phase separated by the gas-liquid separation device (11);

[0082] A gas phase flow rate measuring device (13) for measuring the flow rate of the gas phase separated by the gas-liquid separation device (11);

[0083] a liquid phase reflux line (14) connecting the liquid phase flow rate measuring device (12) with the steam turbine (1); and

[0084] A gas phase reflux line (15) connects the gas phase flow rate measuring device (13) and the steam turbine (1).

[0085] According to the wastewater discharge monitoring device of the present disclosure, since the flow rates of both the liquid phase and the gas phase in the fluid sucked into the internal space of the stationary blade through the slit formed in the stationary blade of the steam turbine are measured, it is possible to understand whether the wastewater is discharged appropriately.

[0086] [2] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to [1], comprising:

[0087] A two-phase flow path (16) connects the internal space (3) with the gas-liquid separation device (11); and

[0088] The bypass line (40) connects the two-phase flow circuit (16) with the gas phase return circuit (15).

[0089] According to such a structure, when it is not necessary to measure the flow rates of the liquid phase and the gas phase, the fluid sucked into the internal space can be returned to the steam turbine via the bypass line and the gas phase return line, thereby reducing the power consumption for flow rate measurement. In addition, it is also possible to perform maintenance on the liquid phase flow rate measuring device and the gas phase flow rate measuring device while continuing the operation of the steam turbine.

[0090] [3] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to [1] or [2],

[0091] The liquid phase flow rate measuring device (12) comprises a tank portion (21) for storing the liquid phase.

[0092] It is provided with a first communication line (50) for connecting the tank body (21) and the gas phase reflux line (15).

[0093] The liquid phase separated by the gas-liquid separation device will transfer to the tank body due to the pressure difference between the gas-liquid separation device and the tank body, but if the pressure difference is small, it becomes difficult for the liquid phase to transfer to the tank body. In contrast, according to the structure of [3] above, since the pressure difference can be increased, the transfer of the liquid phase from the gas-liquid separation device to the tank body can be promoted, thereby improving the reliability of the flow measurement of the liquid phase.

[0094] [4] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to [3], comprising:

[0095] a gas phase flow line (17) connecting the gas-liquid separation device (11) and the gas phase flow rate measuring device (13); and

[0096] The second communication line (60) connects the gas phase flow line (17) and the first communication line (50).

[0097] According to such a configuration, since the liquid phase accumulated in the gas phase flow path can be transferred to the tank portion, the reliability of the gas phase flow rate measurement can be improved.

[0098] [5] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to any one of [1] to [4],

[0099] The gas phase flow rate measuring device (13) comprises a plurality of measuring mechanisms (30).

[0100] The plurality of measuring mechanisms (30) respectively include:

[0101] A pressure measuring device (31) for measuring the pressure of the gas phase;

[0102] a critical nozzle (32) disposed on the downstream side of the pressure measuring device (31); and

[0103] The on-off valve (33) is provided on the upstream side or the downstream side of the pressure measuring device (31) and the critical nozzle (32).

[0104] According to such a configuration, the number of measuring mechanisms used for measuring the flow rate of the gas phase can be adjusted by opening and closing the on-off valves of the measuring mechanisms. Thus, even when the stator blades to be measured are changed or the number of stator blades to be measured is changed, by adjusting the number of measuring devices used, the pressure difference between the upstream and downstream of the slit and the flow rate conditions of the two-phase flow including the liquid phase and the gas phase can be appropriately adjusted, and the flow rate of the gas phase can be appropriately measured.

[0105] [6] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to [5],

[0106] The critical nozzle (32) is a Laval nozzle.

[0107] By using a critical nozzle in a gas phase flow rate measuring device, it is possible to achieve gas phase flow rate measurement only by the pressure on the upstream side of the critical nozzle. However, if the pressure on the downstream side of the gas phase flow rate measuring device rises due to the operating conditions of the steam turbine, the critical pressure ratio may not be reached in the critical nozzle. Even if the pressure on the downstream side of the gas phase flow rate measuring device rises, by using a Laval nozzle as a critical nozzle, the possibility of reaching the critical pressure ratio can be increased, thereby improving the reliability of gas phase flow rate measurement.

[0108] [7] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to any one of [1] to [6],

[0109] The gas-liquid separation device (11) is a cyclone separator.

[0110] According to such a configuration, gas-liquid separation can be performed for a wide range of fluid flow rates.

[0111] [8] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to any one of [1] to [7],

[0112] The liquid phase flow rate measuring device (12) comprises:

[0113] a tank portion (21) for storing the liquid phase; and

[0114] A liquid phase amount detection unit (22) detects the amount of the liquid phase in the tank body (21).

[0115] According to such a configuration, the flow rate of the liquid phase can be acquired over time.

[0116] [9] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to [8],

[0117] The liquid phase reflux line (14) is connected to the tank body (21).

[0118] The liquid phase reflux line (14) is provided with a drain valve (23) which is configured to open when the detection value of the liquid phase amount detection unit (22) reaches a preset upper limit value.

[0119] According to such a configuration, when the amount of the liquid phase in the tank body reaches the upper limit value, the liquid phase can be automatically discharged from the tank body, so that long-term monitoring can be performed.

[0120]

[10] A wastewater discharge monitoring device according to another embodiment is the wastewater discharge monitoring device according to any one of [1] to [9],

[0121] The invention comprises: a control device (20) for transmitting the flow rate of the liquid phase and the flow rate of the gas phase measured by the liquid phase flow rate measuring device (12) and the gas phase flow rate measuring device (13);

[0122] The control device (20) pre-sets an upper limit value and a lower limit value related to the flow rate of the liquid phase and an upper limit value and a lower limit value related to the flow rate of the gas phase,

[0123] The control device (20) detects abnormality in the wastewater discharge based on the respective flow rates of the liquid phase and the gas phase transmitted from the liquid phase flow rate measuring device (12) and the gas phase flow rate measuring device (13) and the upper limit value and the lower limit value related to the respective flow rates of the liquid phase and the gas phase.

[0124] According to such a configuration, the occurrence of abnormality in wastewater discharge and the cause thereof can be automatically detected.

[0125] -Explanation of symbols-

[0126] 1 Steam turbine

[0127] 2 Stationary blades

[0128] 3. Internal Space

[0129] 4 Slit

[0130] 10 Wastewater discharge monitoring device

[0131] 11 Gas-liquid separation device

[0132] 12 Liquid flow measurement device

[0133] 13 Gas phase flow measurement device

[0134] 14 Liquid reflux line

[0135] 15 Gas phase reflux line

[0136] 16 Two-phase flow lines

[0137] 20 Control device

[0138] 21 Tank

[0139] 22 Liquid phase volume detection unit

[0140] 23 Drain valve

[0141] 30 Measuring mechanism

[0142] 31. Pressure measuring device

[0143] 32 Critical Nozzle

[0144] 33 On / Off Valve

[0145] 40 Bypass line

[0146] 50 First connection line

[0147] 60 Second connecting line.

Claims

1. A wastewater discharge monitoring device for monitoring wastewater discharge in a steam turbine caused by sucking a fluid outside the stator blade into the internal space through a slit formed on the surface of at least one hollow stator blade including an internal space, the wastewater discharge monitoring device comprising: a gas-liquid separation device for separating the fluid sucked into the internal space into a liquid phase and a gas phase; A liquid phase flow rate measuring device for measuring the flow rate of the liquid phase separated by the gas-liquid separation device; A gas phase flow rate measuring device for measuring the flow rate of the gas phase separated by the gas-liquid separation device; a liquid phase reflux circuit connecting the liquid phase flow rate measuring device with the steam turbine; as well as A gas phase reflux line connects the gas phase flow rate measuring device to the steam turbine, The liquid phase flow rate measuring device includes a tank body portion which is independent of the gas-liquid separation device and stores the liquid phase, and the end of the liquid phase reflux line is connected to the bottom of the tank body portion. The wastewater discharge monitoring device includes a first communication line that connects the tank portion and the gas phase reflux line.

2. The wastewater discharge monitoring device according to claim 1, wherein: The wastewater discharge monitoring device comprises: A two-phase flow circulation line connecting the internal space with the gas-liquid separation device; and A bypass line connects the two-phase flow circuit with the gas phase reflux circuit.

3. The wastewater discharge monitoring device according to claim 1, wherein: The wastewater discharge monitoring device comprises: A gas phase flow line connecting the gas-liquid separation device with the gas phase flow measurement device; as well as The second communication line connects the gas phase flow line with the first communication line.

4. The wastewater discharge monitoring device according to any one of claims 1 to 3, wherein: The gas phase flow rate measuring device comprises a plurality of measuring mechanisms. The plurality of measuring mechanisms respectively include: A pressure measuring device for measuring the pressure of the gas phase; a critical nozzle disposed on the downstream side of the pressure measuring device; and The on-off valve is provided on the upstream side or the downstream side of the pressure measuring device and the critical nozzle.

5. The wastewater discharge monitoring device according to claim 4, wherein: The critical nozzle is a Laval nozzle.

6. The wastewater discharge monitoring device according to any one of claims 1 to 3, wherein: The gas-liquid separation device is a cyclone separator.

7. The wastewater discharge monitoring device according to any one of claims 1 to 3, wherein: The liquid phase flow rate measuring device also includes: A liquid phase amount detection unit detects the amount of the liquid phase in the tank body.

8. The wastewater discharge monitoring device according to claim 7, wherein: The liquid phase reflux line is provided with a drain valve, and the drain valve is configured to open when the detection value of the liquid phase amount detection unit reaches a preset upper limit value.

9. The wastewater discharge monitoring device according to any one of claims 1 to 3, wherein: The wastewater discharge monitoring device comprises: a control device that transmits the flow rate of the liquid phase and the flow rate of the gas phase measured by the liquid phase flow rate measuring device and the gas phase flow rate measuring device, The control device pre-sets an upper limit value and a lower limit value related to the flow rate of the liquid phase and an upper limit value and a lower limit value related to the flow rate of the gas phase, The control device detects abnormality in the wastewater discharge based on the flow rates of the liquid phase and the gas phase transmitted from the liquid phase flow rate measuring device and the gas phase flow rate measuring device, respectively, and the upper limit value and the lower limit value related to the flow rates of the liquid phase and the gas phase, respectively.

Images