JP6245126B2 - Steam turbine equipment and control method of steam turbine equipment - Google Patents

Description

  The present invention relates to a steam turbine facility and a method for controlling the steam turbine facility, and more particularly to a steam turbine facility for adjusting supply of steam to the steam turbine by a steam control valve and a method for controlling the steam turbine facility.

  As conventional steam turbine equipment, for example, single-flash or double-flash turbine equipment is used, and Patent Document 1 discloses a double-flash turbine equipment.

  The turbine facility of Patent Document 1 is used in a geothermal turbine plant that generates power using a geothermal fluid in which hot water and high-pressure steam are mixed, and includes two steam turbines. In this document, high-pressure steam is separated from hot water by a separator (a steam separator), and this high-pressure steam is supplied to a high-pressure steam turbine serving as one steam turbine. Moreover, the hot water separated by the separator is decompressed by a flasher (a decompression vaporizer) to generate low-pressure steam, and this low-pressure steam is supplied to the low-pressure steam turbine that is the other steam turbine. Each of the high-pressure steam turbine and the low-pressure steam turbine has a casing, and a turbine rotor having a rotating shaft and turbine blades connected to the casing is disposed in the casing. And each rotating shaft of a high pressure steam turbine and a low pressure steam turbine is mutually connected.

JP, 2014-31736, A

  In the high-pressure steam turbine and the low-pressure steam turbine of Patent Document 1, supply of steam into the casing of only one of the steam turbines may stop or the steam may be in an extremely low flow rate state. In this state, when the turbine rotor rotates, the turbine blades rotate in an atmosphere in which the steam is extremely small in the casing, so that the frictional heat between the steam and the turbine blades cannot be cooled by the steam. For this reason, there exists a problem that the heat_generation | fever by a stirring loss occurs within a steam turbine.

  Here, as a case where the supply of steam to only one of the steam turbines is stopped or the squealing loss occurs due to the extremely low flow rate state, for example, an unintended trouble occurs and the inlet valve of the low pressure steam turbine is Since the turbine rotor of the high-pressure steam turbine is rotated while closing, there is a case where the turbine rotor of the low-pressure steam turbine rotates. Moreover, as a case where the steam stirs at an extremely low flow rate, for example, a no-load operation such as when each steam turbine is started, or an extremely low load operation can be considered.

  This invention is made in view of such a situation, and it aims at providing the control method of the steam turbine equipment which can prevent the excessive heat_generation | fever by the stirring loss of a steam turbine, and a steam turbine equipment. .

  The steam turbine equipment according to the present invention includes a plurality of steam turbines connected in series driven by steam supplied from different steam sources, and a flow rate of steam supplied from the steam sources provided in each of the plurality of steam turbines. A steam turbine facility comprising a steam control valve for adjusting and adjusting the operation of the steam control valve by an output of a valve opening command value, wherein the control means includes a plurality of the steam control valves. On the other hand, the valve opening command value having the same value is output simultaneously.

  According to the steam turbine equipment, since the valve opening command value having the same value is output at the same time, a plurality of steam control valves can be opened and closed simultaneously. As a result, in a state where steam is supplied to and driven by one of a plurality of steam turbines having different steam sources, supply of steam to other steam turbines may stop or the steam may have a very low flow rate. Can be prevented. As a result, in all the steam turbines, it is possible to avoid the rotation of the turbine rotor in an atmosphere where there is no or very little steam, and overheating due to stirring loss can be prevented.

  The steam turbine equipment control method according to the present invention includes a plurality of serially connected steam turbines driven by steam supplied from different steam sources, and the steam turbines provided in each of the plurality of steam turbines. A steam turbine equipment control method comprising a steam control valve for adjusting and adjusting steam, and simultaneously outputting a valve opening command value of the same value to a plurality of the steam control valves. The operation of the plurality of steam control valves is controlled by the output of

  According to the present invention, since the valve opening command value having the same value is output at the same time, excessive heat generation due to the stirring loss of the steam turbine can be prevented.

It is a schematic structure figure of the steam turbine equipment concerning a 1st embodiment. It is a graph utilized with the characteristic table which concerns on 1st Embodiment. It is a flowchart which shows an example of the control at the time of abnormality of the said steam turbine equipment. It is a flowchart which shows an example of the control at the time of abnormality of the said steam turbine equipment. It is a flowchart which shows an example of the control at the time of abnormality of the said steam turbine equipment. It is a flowchart which shows an example of the control at the time of abnormality of the said steam turbine equipment. It is a flowchart which shows an example of the control at the time of abnormality of the said steam turbine equipment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 2nd Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 3rd Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 4th Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 5th Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 6th Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 7th Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 8th Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 9th Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment concerning 10th Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment concerning 11th Embodiment. It is a schematic block diagram which shows a part of steam turbine equipment which concerns on 12th Embodiment.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of the steam turbine equipment according to the first embodiment. In the following, for convenience of explanation, a geothermal power plant will be described as an example of a power plant. However, the power plant to which the steam turbine equipment according to the present invention is applied is not limited to this and can be appropriately changed. For example, it may be applied to a thermal power plant, or may be applied to a power plant using any other steam source or a binary power plant using a gas other than steam.

  In the following first embodiment, regarding two types of steam having roughly different pressures, a relatively high pressure is “high pressure”, while a relatively low pressure is “medium pressure”. ".

  As shown in FIG. 1, the steam turbine equipment 1 according to the present embodiment includes a first flasher (steam source) 3, a second flasher (steam source) 4, a high-pressure steam turbine (first steam turbine) 5, and an intermediate pressure. A steam turbine (second steam turbine) 6, a generator 8, a condenser 9 and a control means 10 are provided. Each of the steam turbines 5 and 6 includes a casing in which steam is supplied. Therefore, the steam turbine equipment 1 according to the first embodiment is a double-flash two-casing geothermal turbine equipment.

  The 1st flasher 3 is comprised by the steam separator (separator) which isolate | separates the geothermal fluid extract | collected from the production well 12 into a hot water and a high pressure steam. The first flasher 3 is supplied with geothermal fluid from the production well 12 through the geothermal fluid supply pipe 13. The high-pressure steam separated by the first flasher 3 is introduced into the high-pressure steam turbine 5 through the high-pressure steam supply pipe 14. Accordingly, the first flasher 3 functions as a steam source for the high-pressure steam turbine 5. The hot water separated by the first flasher 3 is introduced into the second flasher 4 via the hot water supply pipe 15. The geothermal fluid supply pipe 13 is provided with a flow rate adjustment valve 17 that adjusts the flow rate of the high-pressure geothermal fluid, and the hot water supply pipe 15 adjusts the amount (level) of hot water in the first flasher 3. A level control valve 18 is provided.

  The second flasher 4 depressurizes the hot water supplied from the first flasher 3 and uses a reduced pressure vaporizer (flasher) that separates the hot water having a temperature lower than that of the hot water and an intermediate pressure steam having a pressure lower than that of the high pressure steam. Composed. The hot water separated by the second flasher 4 is discharged to the reduction well 21 through the hot water discharge pipe 20. The hot water supply pipe 20 is provided with a level control valve 19 that adjusts the amount (level) of hot water in the second flasher 4. The intermediate pressure steam separated by the second flasher 4 is introduced into the intermediate pressure steam turbine 6 through the intermediate pressure steam supply pipe 22. Therefore, the second flasher 4 functions as a steam source for the intermediate pressure steam turbine 6.

  The high-pressure steam turbine 5 is driven by high-pressure steam supplied via a high-pressure steam supply pipe 14. The high-pressure steam turbine 5 has a turbine rotor installed inside the casing, and the turbine rotor includes a plurality of turbine blades fixed to the rotary shaft 24 and is rotatably supported. The high-pressure steam turbine 5 is a single-flow turbine in which a high-pressure steam inlet is provided on one side in the extending direction of the rotating shaft 24 and a high-pressure steam outlet is provided on the other side in the extending direction of the rotating shaft 24. A high-pressure steam supply pipe 14 is connected to the casing of the high-pressure steam turbine 5, and this connection position serves as a high-pressure steam inlet. High-pressure steam is supplied into the casing of the high-pressure steam turbine 5 via the high-pressure steam supply pipe 14, and the supplied high-pressure steam performs work to rotate the turbine rotor. The high-pressure steam that has performed work is discharged to the condenser 9 through the first steam discharge pipe 25 connected to the casing. The connection position of the first steam discharge pipe 25 with respect to the casing is a high-pressure steam outlet.

  The intermediate pressure steam turbine 6 is driven by intermediate pressure steam supplied through an intermediate pressure steam supply pipe 22. Similar to the high-pressure steam turbine 5, the intermediate-pressure steam turbine 6 has a turbine rotor installed inside the casing, and the turbine rotor includes a plurality of turbine blades fixed to the rotary shaft 27 and is rotatably supported. Has been. One end side of the rotary shaft 27 in the intermediate-pressure steam turbine 6 is connected to the rotary shaft 24 of the high-pressure steam turbine 5, and they are simultaneously rotated in the same direction at the same rotational speed. Therefore, the intermediate pressure steam turbine 6 and the high pressure steam turbine 5 are connected in series. The other end side of the rotating shaft 27 in the intermediate pressure steam turbine 6 is connected to the generator 8. The intermediate pressure steam turbine 6 is a single-flow turbine in which an intermediate pressure steam inlet is provided on one side in the extending direction of the rotating shaft 27 and an intermediate pressure steam outlet is provided on the other side in the extending direction of the rotating shaft 27. An intermediate pressure steam supply pipe 22 is connected to the casing of the intermediate pressure steam turbine 6, and this connection position serves as an intermediate pressure steam inlet. The intermediate pressure steam is supplied into the casing of the intermediate pressure steam turbine 6 through the intermediate pressure steam supply pipe 22, and the supplied intermediate pressure steam performs work to rotate the turbine rotor. The medium-pressure steam that has performed work is discharged to the condenser 9 through the second steam discharge pipe 28 connected to the casing. The connection position of the second steam discharge pipe 28 with respect to the casing is an intermediate pressure steam outlet.

  The high pressure steam supply pipe 14 is provided with a high pressure steam stop valve 31 and a high pressure steam control valve 32. The intermediate pressure steam supply pipe 22 is provided with an intermediate pressure steam stop valve 33 and an intermediate pressure steam control valve 34. The high-pressure steam stop valve 31 and the intermediate-pressure steam stop valve 33 are for shutting off the steam introduced into the steam turbines 5 and 6. The high pressure steam control valve 32 and the medium pressure steam control valve 34 are for adjusting the flow rate of the steam introduced into the steam turbines 5 and 6. Each steam control valve 32, 34 is controlled in valve opening degree via the control means 10. In the high-pressure steam supply pipe 14, a high-pressure vent valve 35 is provided on the upstream side of the high-pressure steam stop valve 31, and in the intermediate-pressure steam supply pipe 22, an intermediate-pressure vent valve is provided on the upstream side of the intermediate-pressure steam stop valve 33. 36 is provided. Each of the vent valves 35 and 36 is opened when the pressure in each of the steam supply pipes 14 and 22 exceeds a predetermined value, and discharges the steam to the outside of the steam supply pipe such as the atmosphere or the condenser 9, and the pressure is a predetermined value. When it becomes smaller, the valve is closed to stop the discharge of steam.

  The condenser 9 condenses the steam by cooling the steam discharged from the steam turbines 5 and 6. Instead of the condenser 9, another heat exchanger or a system outside the turbine such as a system utilizing steam may be used.

  Here, the generator 8 is provided with a power detector 40 for detecting the output power value. Either one of the rotation shafts 24 and 27 is provided with a rotation speed detector 41 for detecting the rotation speed (per unit time) of the rotation shafts 24 and 27. In the high-pressure steam supply pipe 14, a high-pressure detector (pressure detector) 42 is provided upstream of the high-pressure steam stop valve 31 and the high-pressure steam control valve 32, and the intermediate-pressure steam supply pipe 22 has an intermediate-pressure steam stop. An intermediate pressure detector (pressure detector) 43 is provided upstream of the valve 33 and the intermediate pressure steam control valve 34. The high pressure detector 42 detects the pressure value of the high pressure steam in the high pressure steam supply pipe 14 upstream of the high pressure steam stop valve 31 and the high pressure steam control valve 32, and the intermediate pressure detector 43 is the intermediate pressure steam stop valve 33. And the pressure value of the intermediate pressure steam in the intermediate pressure steam supply pipe 22 upstream of the intermediate pressure steam control valve 34 is detected.

  Next, the configuration of the control means 10 will be described. In FIG. 1, the control means 10 is shown as a functional block diagram. The functional block of the control means 10 shown in FIG. 1 shows only the configuration related to the present invention, and the other configuration is omitted. In addition, the control means 10 is comprised including the processor which performs the various processes required for the operation control of the steam turbine equipment 1, for example.

  As shown in FIG. 1, the control means 10 is comprised including the input part 10a, the calculating part 10b, the characteristic table 10c, and the output part 10d, and can control the driving | operation of the steam turbine equipment 1. FIG. The input unit 10a inputs detection results output from various measuring instruments of the steam turbine equipment 1 including the detectors 40 to 43 as electrical signals.

  Based on the detection result input to the input unit 10a, the calculation unit 10b calculates the valve opening degrees of the high-pressure steam control valve 32 and the intermediate pressure steam control valve 34 as described later. In the calculation unit 10b, for the valve opening command value and the additional valve opening command value for commanding the valve opening of the high pressure steam control valve 32 and the intermediate pressure steam control valve 34, "rotational speed control", "output control", Calculation is performed by switching three control modes of “pre-pressure control”. In the rotational speed control, calculation is performed based on the rotational speeds of the rotary shafts 24 and 27 output from the rotational speed detector 41. The output control is calculated based on the output power value of the generator 8 output from the power detector 40. The pre-pressure control is calculated based on the steam pressure values output from the high pressure detector 42 and the intermediate pressure detector 43. In these three control modes, the steam flow rate supplied to the steam turbines 5 and 6 from the steam control valves 32 and 34 is obtained based on the detection results of the detectors 40 to 43, and each steam corresponding to the flow rate is obtained. The valve opening command value and the additional valve opening command value of the adjusting valves 32 and 34 are calculated. In the calculation by the calculation unit 10b, the characteristic table 10c is referred to.

  FIG. 2 shows a graph used in the characteristic table. This graph shows the relationship between the steam flow rate (horizontal axis) at the high pressure steam control valve 32 and the medium pressure steam control valve 34 and the valve opening command value (vertical axis). In FIG. 2, a graph (A) shows the relationship between the steam flow rate of the high-pressure steam control valve 32 and the valve opening command value. The graph (B) shows the relationship between the steam flow rate of the intermediate pressure steam control valve 34 and the valve opening command value. Therefore, in the graph of FIG. 2, the relationship of each steam flow rate of the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 with respect to the valve opening command value is set.

  In the graph (A) and the graph (B), the valve opening command value (about 28% in the present embodiment) at which the steam flow is no longer 0 and the steam starts to flow is set to be the same. In graphs (A) and (B), the valve opening command value increases as the steam flow rate increases. The graph showing the high-pressure steam control valve 32 with respect to the same valve opening command value. The steam flow rate is higher in (A).

  The graph (A) is set so that the steam flow rate is constant when the valve opening command value is equal to or higher than the upper limit value (about 80% in the present embodiment). That is, in the high-pressure steam control valve 32, when the valve opening command value becomes larger than the upper limit value, the valve opening is controlled to be constant without changing. Graph (B) is linear so that the valve opening command value is equal to or greater than the upper limit set value (about 50% in the present embodiment) and the steam flow rate is a constant value (about 70 t / h in the present embodiment). Is set. That is, in the intermediate pressure steam control valve 32, when the valve opening command value becomes larger than the upper limit set value, the valve opening is controlled to be constant without changing. Here, the region (D) surrounded by the straight line portion of the graph (B) and the dotted line (C) is a straight line of the graph (B) according to the additional valve opening command value in the pre-pressure control by the intermediate pressure steam control valve 34. The steam flow increased from the part is shown. Note that the above and following numerical values of the valve opening command value and the steam flow rate are merely examples, and can be appropriately changed according to various conditions of the steam turbine equipment 1.

  The output unit 10d outputs the valve opening calculated by the calculation unit 10b as an electrical signal to the high pressure steam control valve 32 and the intermediate pressure steam control valve 34, and the high pressure steam control valve 32 and the medium pressure steam are output via this output. The operation of the steam turbine equipment 1 is controlled by controlling the opening / closing operation of the control valve 34. The output unit 10d simultaneously outputs a valve opening command value (for example, 40% for both valve opening command values) having the same value to the high pressure steam control valve 32 and the intermediate pressure steam control valve 34. Thereby, the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 are simultaneously opened and closed. Further, in the pre-pressure control by the intermediate pressure steam control valve 34, the output unit 10d outputs an additional valve opening command value to the intermediate pressure steam control valve 34. With this additional valve opening command value, the intermediate pressure steam is output. The opening / closing operation of only the adjusting valve 34 is controlled.

  Next, a method for starting the steam turbine facility 1 will be described.

  Here, the flow control valve 17, the level control valves 18 and 19, the high pressure steam stop valve 31, the high pressure steam control valve 32, the intermediate pressure steam stop valve 33 and the intermediate pressure steam control valve 34 are closed, and the high pressure steam turbine 5 is closed. The intermediate pressure steam turbine 6 is stopped. Further, the generator 8 connected to the rotating shaft 27 is not turned on synchronously and is stopped together with the high-pressure steam turbine 5 and the intermediate-pressure steam turbine 6. After passing the turning operation from this state, first, the flow rate adjusting valve 17 is opened at a predetermined valve opening, and the level control valves 18 and 19 are automatically controlled. Then, in the first flasher 3, the introduced geothermal fluid is separated into hot water and high-pressure steam, and high-pressure steam is supplied to the high-pressure steam supply pipe 14. Further, the hot water separated by the first flasher 3 is introduced into the second flasher 4 through the hot water supply pipe 15 and separated into intermediate pressure steam and hot water, and the intermediate pressure steam is supplied to the intermediate pressure steam supply pipe 22. Is supplied.

  In a state where steam is supplied to the high-pressure steam supply pipe 14 and the intermediate-pressure steam supply pipe 22, surplus steam is released to the atmosphere or the like via the high-pressure vent valve 35 and the intermediate-pressure vent valve 36, and each steam supply pipe 14, The pressure value of 22 is set below a predetermined value. In this state, after the steam shutoff by the stop valves 31 and 33 is released, the rotational speed control is performed for the steam turbines 5 and 6. In the rotational speed control, the control means 10 outputs a valve opening command value to each of the steam control valves 32 and 34 according to the rotational speed of the rotary shafts 24 and 27 input from the rotational speed detector 41. The valve opening command values output to the steam control valves 32 and 34 are the same and are output simultaneously. Thus, the steam control valves 32 and 34 are simultaneously opened from the closed state by the same valve opening command value. When each of the steam control valves 32 and 34 is increased in accordance with the valve opening command value, steam is supplied into the casings of the steam turbines 5 and 6, and the supplied steam works. The turbine rotor is rotated. And the rotating shafts 24 and 27 and the generator 8 of a turbine rotor are controlled so that it may become a rated rotation speed (for example, 3000 rpm).

  In the control means 10, the turbine rotor rotation shafts 24 and 27 and the rotational speed of the generator 8 that are input are synchronized after the rotational speed reaches the rated rotational speed, and the control is shifted from rotational speed control to output control. In the output control, the generator 8 starts the power generation by increasing the load from the extremely low load, and the output power value detected by the output detector 40 is input to the control means 10. In the control means 10, the same valve opening command value is simultaneously output to each of the steam control valves 32 and 34, and the load (output power) of the generator 8 is controlled to gradually increase.

  When the load (output power) of the generator 8 is increased in the output control, the work of steam in each of the steam turbines 5 and 6 is increased, so that the pressure of the high-pressure steam supply pipe 14 is reduced and the high-pressure vent valve 35 is increased. Is fully closed. When the pre-pressure control is performed in the high-pressure steam turbine 5 by fully closing the high-pressure vent valve 35, the output control is shifted to the pre-pressure control. Note that output control may be continued without performing this transition, and the selection differs depending on the plant.

  In the pre-pressure control of the high-pressure steam turbine 5, the pressure of the high-pressure steam in the high-pressure steam supply pipe 14 that is the previous stage of the high-pressure steam turbine 5 is detected by the high-pressure detector 42 and input to the control means 10. Then, the control means 10 outputs a valve opening command value to the high-pressure steam control valve 32 so that the pressure value approximates the rated pressure according to the pressure value input from the high-pressure detector 42. At this time, the same valve opening command value as the valve opening command value output to the high pressure steam control valve 32 is simultaneously output to the intermediate pressure steam control valve 34. However, when the valve opening command value is equal to or greater than the upper limit set value (about 50%), the valve opening of the intermediate pressure steam control valve 34 does not increase and becomes constant (see graph (B) in FIG. 2). .

  In the control means 10, after the input pressure value of the high-pressure detector 42 is controlled to the rated pressure, preparation for pre-pressure control of the intermediate pressure steam turbine 6 is performed. In this preparation, it is necessary to increase the steam flow rate in the portion indicated by the region (D) in FIG. On the other hand, in the graph (B) of FIG. 2, when the valve opening command value is about 50% or more, the valve opening of the intermediate pressure steam control valve 34 is constant without increasing, and the intermediate pressure vent valve 36 is controlled. Since the steam is released to the atmosphere or the like, the steam flow rate is constant at about 70 t / h. Therefore, control (for example, manual) different from the control based on the valve opening command value is added, and the opening of the intermediate pressure steam control valve 34 is increased until the intermediate pressure vent valve 36 is closed. When the intermediate pressure vent valve 36 is closed, preparation for pre-pressure control in the intermediate-pressure steam turbine 6 is completed, and when pre-pressure control is performed in the intermediate-pressure steam turbine, the pre-pressure control is started.

  In this pre-pressure control, since the pressure value of the intermediate pressure detector 43 is controlled to the rated pressure, the pressure value approximates to the rated pressure in the control means 10 according to the pressure value input from the intermediate pressure detector 43. As described above, the additional valve opening command value is output to the intermediate pressure steam control valve 34. In the pre-pressure control of the intermediate pressure steam turbine 6, the valve opening command value output to the intermediate pressure steam control valve 34 is the same as the valve opening command value output to the high pressure steam control valve 32. The output state is maintained at the same time.

  As described above, in the pre-pressure control of the intermediate pressure steam turbine 6, the additional valve opening command value is output in addition to the valve opening command value. Therefore, when the valve opening command value is equal to or higher than the upper limit set value (about 50%), the steam flow rate does not become less than about 70 t / h. Thereby, even if the intermediate pressure steam detected by the intermediate pressure detector 43 is reduced in pressure and the intermediate pressure steam control valve 34 operates in the closing direction by the additional valve opening command value, the intermediate pressure steam control valve 34 The lower limit value of the steam flow rate is set to about 70 t / h.

  In the control means 10, when the input pressure values of the high pressure detector 42 and the intermediate pressure detector 43 are controlled to the rated pressure, the flow rate adjusting valve 17 is increased by a predetermined valve opening, and the flashers 3 and 4 Increase the high and medium pressure steam supplied. Then, the supplied high-pressure steam and medium-pressure steam are controlled to have a rated flow rate, the generator 8 reaches the rated load, and the startup of the steam turbine equipment 1 is completed.

  When the steam turbine facility 1 is started, the same valve opening command value is output simultaneously, so that the steam control valves 32 and 34 are simultaneously opened from the closed state to increase the opening. Thereby, it is possible to prevent the supply of steam from being stopped or the flow rate from becoming extremely low by only one of the high-pressure steam turbine 5 and the intermediate-pressure steam turbine 6. As a result, when the steam turbines 5 and 6 are started, it is possible to avoid the occurrence of overheating due to the stirring loss inside the steam turbines 5 and 6.

  In addition, in the pre-pressure control of the intermediate pressure steam turbine 6, when the valve opening command value is equal to or higher than the upper limit set value, the steam flow rate does not become smaller than a certain value. It is possible to prevent the occurrence of overheating inside the intermediate pressure steam turbine 6.

After the start-up of the steam turbine equipment 1 is completed, the generator 8 is operated as a rated load, and the control of the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 in each steam turbine 5, 6 is as follows (1) to (3 ) Is switched according to various conditions (hereinafter referred to as “normal operation”).
(1) High-pressure steam turbine 5: Pre-pressure control, medium-pressure steam turbine 6: Pre-pressure control (2) High-pressure steam turbine 5: Output control, Medium-pressure steam turbine 6: Pre-pressure control (3) High-pressure steam turbine 5: Output Control, medium pressure steam turbine 6: Control according to valve opening command value

  In normal operation, the pre-pressure control of the high-pressure steam turbine 5 controls the valve opening degree of the high-pressure steam control valve 32 based on the pressure value of the high-pressure steam detected by the high-pressure detector 42 as in the start-up. Further, in the output control of the high-pressure steam turbine 5, the valve opening degree of the high-pressure steam control valve 32 is controlled based on the output electric power value detected by the output detector 40 as in the start-up. In any of the normal operation patterns (1) to (3), the valve opening command value that is the same as the valve opening command value output to the high-pressure steam control valve 32 by the control means 10 is the medium pressure steam control mode. Simultaneously output to the valve 34.

  In normal operation, the pre-pressure control of the intermediate pressure steam turbine 6 is such that the valve opening command value to the intermediate pressure steam control valve 34 is equal to or higher than the upper limit set value (about 50%), and the additional valve opening command value is medium. It is output to the pressure steam control valve 34. Therefore, in the pre-pressure control of the intermediate pressure steam turbine 6, the valve opening degree of the intermediate pressure steam control valve 34 is adjusted by the additional valve opening command value based on the pressure value of the intermediate pressure steam detected by the intermediate pressure detector 43. Be controlled.

  By the way, during operation of the steam turbine facility 1, when the operation is abnormal when the pressure of high-pressure steam or medium-pressure steam is suddenly reduced due to an unintended trouble or the like (for example, a plurality of atmospheric discharge plates downstream of the first flasher 3 In this embodiment, control corresponding to this is performed. Before explaining the control, as a comparative example different from the present embodiment, the above-described (1) to (3) will be described with respect to a state assumed when the control is not performed and the pressure of the high-pressure steam rapidly decreases. This will be described below. In the comparative example of the patterns (1) and (2), the respective steam control valves 32 and 34 are controlled separately and independently.

[Pattern of (1)]
When the pressure of the high-pressure steam is suddenly reduced, the high-pressure detector 42 detects the pressure value and inputs it to the control means 10. In response to this input, the control means 10 outputs a command for operating the high-pressure steam control valve 32 in the valve closing direction in order to increase the pressure in the high-pressure steam supply pipe 14. Therefore, the steam inside the high-pressure steam turbine 5 is extremely reduced. On the other hand, in the intermediate pressure steam control valve 34, the prepressure control is continued and the valve remains open, and the supply of the intermediate pressure steam to the intermediate pressure steam turbine 6 is continued. As a result, not only the turbine rotor of the medium-pressure steam turbine 6 but also the turbine rotor of the high-pressure steam turbine 5 is rotated, and overheating due to the stirring loss occurs in the high-pressure steam turbine 5.

[Pattern (2)]
Even if the pressure of the high-pressure steam is suddenly reduced, the high-pressure steam control valve 32 remains open regardless of the pressure drop, but the high-pressure steam supplied to the high-pressure steam turbine 5 is stopped or has a low flow rate. On the other hand, in the intermediate pressure steam control valve 34, the prepressure control is continued and the valve remains open, and the supply of the intermediate pressure steam to the intermediate pressure steam turbine 6 is continued. As a result, not only the turbine rotor of the medium-pressure steam turbine 6 but also the turbine rotor of the high-pressure steam turbine 5 is rotated, and overheating due to the stirring loss occurs in the high-pressure steam turbine 5.

[Pattern (3)]
Even if the pressure of the high-pressure steam is suddenly reduced, the high-pressure steam control valve 32 remains open regardless of the pressure drop, but the high-pressure steam supplied to the high-pressure steam turbine 5 is stopped or has a low flow rate. On the other hand, since the intermediate pressure steam control valve 34 is controlled with the same valve opening command value as the high pressure steam control valve 32, the valve remains open and the supply of the intermediate pressure steam to the intermediate pressure steam turbine 6 is continued. The As a result, not only the turbine rotor of the medium-pressure steam turbine 6 but also the turbine rotor of the high-pressure steam turbine 5 is rotated, and overheating due to the stirring loss occurs in the high-pressure steam turbine 5.

  Subsequently, in the present embodiment, a description will be given of the control of the abnormal operation in which the pressure of the high-pressure steam is rapidly reduced. The control according to the present embodiment may include “high pressure limit pressure control” and “medium pressure limit pressure control”. "High pressure limit pressure control" is a condition in which the steam pressure value detected by the high pressure detector 42 in the control means 10 is less than or equal to the "limit pressure" that is a specified value. A valve opening command value that operates both in the valve closing direction is output. The “intermediate pressure limit pressure control” closes both the steam control valves 32 and 34 on condition that the steam pressure value detected by the intermediate pressure detector 43 is equal to or less than the “limit pressure” that is a specified value. A valve opening command value that operates in the valve direction is output. In these limit pressure controls, the steam control valves 32 and 34 are closed to prevent the pressure drop of the steam supply pipes 14 and 22. The limit pressures of the high pressure detector 42 and the intermediate pressure detector 43 are different pressure values.

[Pattern of (1)]
This will be described below with reference to the flowchart of FIG. FIG. 3 is a flowchart showing the control at the time of abnormality (at the time of high pressure steam pressure rapid drop) in the pattern (1). First, in the pre-pressure control of the high-pressure steam turbine 5, when the pressure of the high-pressure steam is suddenly reduced, the high-pressure detector 42 detects the pressure value of the high-pressure steam and inputs it to the control means 10. In response to this input, the control means 10 has the same valve opening degree that operates in the valve closing direction for both the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 in order to increase the pressure in the high pressure steam supply pipe 14. Command value is output at the same time. By the output of the valve opening command value, the high-pressure steam control valve 32 is operated in the valve closing direction (step (hereinafter referred to as “ST”) 101). Note that the valve opening degree of the intermediate pressure steam control valve 34 does not change because the valve opening command value is equal to or higher than the upper limit setting value (about 50%) before the determination in ST102 described later.

  Next, the valve opening command value of each of the steam control valves 32 and 34 is compared with the “permitted opening” that is the designated value, and it is determined whether or not to continue the pre-pressure control of the intermediate pressure steam. (ST102). This permitted opening is a valve opening command value (about 50% in FIG. 2) that is an upper limit set value in the graph (B) of FIG. In ST102, when it is determined that the valve opening degree of each of the steam control valves 32 and 34 is not less than or equal to the allowable opening degree (greater than the allowable opening degree) for a predetermined determination time, the abnormality has been resolved, and control at that time is performed. That is, the steam turbines 5 and 6 are operated in a state where the pre-pressure control is continued (ST103).

  In ST102, when it is determined that the valve opening command value of each of the steam control valves 32, 34 is equal to or less than the permitted opening, the intermediate pressure steam turbine 6 ends the pre-pressure control and performs control according to the valve opening command value. Migrated (ST104). After ST104, a valve opening command value for operating the high-pressure steam control valve 32 in the valve closing direction is output (ST106). Simultaneously with ST106, in the control means 10, the same valve opening command value as the valve opening command value of the high pressure steam control valve 32 is simultaneously output to the intermediate pressure steam control valve 34, and the intermediate pressure steam control valve 34 is in the valve closing direction. Operated (ST107). If the abnormality is not resolved after the start of operation of ST106 and ST107, a command to fully close both the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 is output, and the steam turbines 5 and 6 are stopped. .

[Pattern (2)]
Hereinafter, a description will be given with reference to the flowchart of FIG. FIG. 4 is a flowchart showing the control at the time of abnormality (at the time of rapid decrease in high-pressure steam pressure) in the pattern (2). First, when the pressure of the high-pressure steam is suddenly reduced, the high-pressure detector 42 detects the pressure value of the high-pressure steam and inputs it to the control means 10 for a predetermined determination time by the high-pressure limit pressure control. Is less than or equal to the limit pressure (ST201). If it is determined in ST201 that the pressure value detected by the high pressure detector 42 is greater than the limit pressure (not less than the limit pressure), the abnormality has been resolved. Therefore, the control at that time, that is, the output control of the high-pressure steam turbine 5 and the pre-pressure control of the intermediate-pressure steam turbine 6 are operated in a continuous state (ST202).

  In ST201, when it is determined that the pressure value of the high pressure steam detected by the high pressure detector 42 is equal to or lower than the limit pressure for a predetermined determination time, both the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 are closed. The same valve opening command value that operates in the direction is output simultaneously. By the output of the valve opening command value, the high pressure steam control valve 32 is operated in the valve closing direction (ST203). Note that the valve opening degree of the intermediate pressure steam control valve 34 does not change because the valve opening command value is equal to or higher than the upper limit set value (about 50%) before the determination in ST204 described later.

  After ST203, the valve opening command value of the intermediate pressure steam control valve 34 is compared with the “permitted opening” that is a specified value, and it is determined whether or not to continue the prepressure control of the intermediate pressure steam. (ST204). This permitted opening is a valve opening command value (about 50%) that is an upper limit set value. In ST204, when it is determined that the valve opening command value is not equal to or smaller than the permitted opening (larger than the permitted opening) for a predetermined determination time, the abnormality has been resolved, and control at that time, that is, the high-pressure steam turbine No. 5 high pressure limit pressure control (during output control) and pre-pressure control of the intermediate pressure steam turbine 6 are continued (ST204a).

  If it is determined in ST204 that the valve opening command value is equal to or smaller than the permitted opening, the pre-pressure control of the intermediate pressure steam turbine 6 is terminated and the control is shifted to the control according to the valve opening command value (ST205). After ST205, a valve opening command value for operating the high pressure steam control valve 32 in the valve closing direction is output (ST206). Simultaneously with ST206, in the control means 10, the same valve opening command value as the valve opening command value of the high-pressure steam control valve 32 is simultaneously output to the intermediate pressure steam control valve 34, and the intermediate pressure steam control valve 34 is in the valve closing direction. Operated (ST207). If the abnormality is not resolved after the start of operation of ST206 and ST207, a command to fully close both the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 is output, and the steam turbines 5 and 6 are stopped. .

[Pattern (3)]
Hereinafter, a description will be given with reference to the flowchart of FIG. FIG. 5 is a flowchart showing the control at the time of abnormality (at the time of rapid decrease in high-pressure steam pressure) in the pattern (3). First, when the pressure of the high-pressure steam is suddenly reduced, the high-pressure detector 42 detects the pressure value of the high-pressure steam and inputs it to the control means 10 for a predetermined determination time by the high-pressure limit pressure control. Is less than or equal to the limit pressure (ST301). If it is determined in ST301 that the pressure value detected by the high pressure detector 42 is greater than the limit pressure (not less than the limit pressure), the abnormality has been resolved. Therefore, the control at that time, that is, the output control of the high-pressure steam turbine 5 and the control according to the valve opening command value of the intermediate-pressure steam turbine 6 are continued (ST302).

  In ST301, when it is determined that the pressure value of the high-pressure steam detected by the high-pressure detector 42 is equal to or lower than the limit pressure for a predetermined determination time, a valve opening command value for operating the high-pressure steam control valve 32 in the valve closing direction is output. (ST303). Simultaneously with ST303, the control means 10 outputs the same valve opening command value as the valve opening command value of the high pressure steam control valve 32 to the intermediate pressure steam control valve 34 at the same time. Then, the operation of the high pressure steam control valve 32 in the valve closing direction is continued as it is (ST304), and the intermediate pressure steam control valve 34 is operated in the valve closing direction (ST305). If the abnormality is not resolved after the start of operation of ST304 and ST305, a command to fully close both the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 is output, and the steam turbines 5 and 6 are stopped. .

  Next, in the present embodiment, a description will be given of the control during abnormal operation in which the pressure of the medium-pressure steam is suddenly reduced.

[Pattern of (1)]
Hereinafter, a description will be given with reference to the flowchart of FIG. FIG. 6 is a flowchart showing the control at the time of abnormality (at the time of sudden drop in the intermediate pressure steam pressure) in the pattern (1). First, in the pre-pressure control of the intermediate pressure steam turbine 6, when the pressure of the intermediate pressure steam is suddenly reduced, the intermediate pressure detector 43 detects the pressure value of the intermediate pressure steam and inputs it to the control means 10. In response to this input, the control means 10 outputs an additional valve opening command value that operates in the valve closing direction to the intermediate pressure steam control valve 34 in order to increase the pressure in the intermediate pressure steam supply pipe 22. By outputting the additional valve opening command value, the intermediate pressure steam control valve 34 is operated in the valve closing direction (ST401).

  After the operation of ST401, the valve opening command value of each of the steam control valves 32, 34 is compared with the “permitted opening” that is the designated value, and whether or not to continue the pre-pressure control of the intermediate pressure steam is determined. It is determined (ST402). This permitted opening is a valve opening command value (about 50%) that is an upper limit set value. In ST402, when it is determined that the valve opening command value is not less than or equal to the permitted opening (greater than the permitted opening) for a predetermined determination time, the abnormality has been resolved, and control at that time, that is, each steam turbine It is operated in a state where the pre-pressure control of 5 and 6 is continued (ST403).

  In ST402, when it is determined that the valve opening command value is equal to or smaller than the permitted opening, the intermediate pressure steam turbine 6 ends the pre-pressure control and shifts to control according to the valve opening command value (ST404). After ST404, as the intermediate pressure limit pressure control of the intermediate pressure steam turbine 6, a predetermined determination time, the intermediate pressure detector 43 detects the pressure value of the intermediate pressure steam and is input to the control means 10, and the predetermined determination time, It is determined whether the pressure value of the medium pressure steam is equal to or lower than the limit pressure (ST407). In ST407, when it is determined that the pressure value detected by the intermediate pressure detector 43 is greater than the limit pressure (not less than the limit pressure), the abnormality is resolved. Therefore, the control at that time, that is, the pre-pressure control of the high-pressure steam turbine 5 and the control according to the valve opening command value of the intermediate-pressure steam turbine 6 are operated (ST408).

  In ST407, when the pressure value of the intermediate pressure steam detected by the intermediate pressure detector 43 is determined to be equal to or lower than the limit pressure for a predetermined determination time, the intermediate pressure steam control valve 34 is operated in the valve closing direction as in ST404. The valve opening command value to be output is output (ST409). Simultaneously with ST409, in the control means 10, the same valve opening command value as the valve opening command value of the intermediate pressure steam control valve 34 is simultaneously output to the high pressure steam control valve 32, and the high pressure steam control valve 32 operates in the valve closing direction. (ST410). If the abnormality is not resolved after the start of operations in ST409 and ST410, a command to fully close both the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 is output, and the steam turbines 5 and 6 are stopped. .

[Pattern (2)]
The pattern (2) has the same process flow except that the operation in ST403, ST407, and ST408 in the pattern (1) is changed as follows. Therefore, description of the pattern (2) using a flowchart is omitted.

  In the pattern (2), ST403 is operated in a state where the output control of the high-pressure steam turbine 5 and the pre-pressure control of the intermediate-pressure steam turbine 6 are continued. In ST407, medium pressure limit pressure control is performed during output control of the high-pressure steam turbine 5, and output control is performed on the high-pressure steam turbine 5 in ST408.

[Pattern (3)]
Hereinafter, a description will be given with reference to the flowchart of FIG. FIG. 7 is a flowchart showing the control at the time of abnormality in the pattern (3) (at the time of sudden drop in the intermediate pressure steam pressure). First, when the pressure of the intermediate pressure steam is suddenly reduced, the intermediate pressure detector 43 detects the pressure value of the intermediate pressure steam by the intermediate pressure limit pressure control of the intermediate pressure steam turbine 6 and inputs it to the control means 10. It is determined whether the pressure value of the medium pressure steam is equal to or lower than the limit pressure (ST501). In ST501, when it is determined that the pressure value detected by the intermediate pressure detector 43 is greater than the limit pressure (not less than the limit pressure) for a predetermined determination time, the abnormality is eliminated. Therefore, the control at that time, that is, the output control of the high-pressure steam turbine 5 and the control according to the valve opening command value of the intermediate-pressure steam turbine 6 are operated (ST502).

  In ST501, when the pressure value of the intermediate pressure steam detected by the intermediate pressure detector 43 is determined to be equal to or lower than the limit pressure for a predetermined determination time, the valve opening degree command for operating the intermediate pressure steam control valve 34 in the valve closing direction. A value is output (ST503). Simultaneously with ST503, in the control means 10, the same valve opening command value as the valve opening command value of the intermediate pressure steam control valve 34 is simultaneously output to the high pressure steam control valve 32, and the high pressure steam control valve 32 operates in the valve closing direction. (ST504). If the abnormality is not resolved after the operation of ST503 and ST504 is started, a command to fully close both the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 is output, and the steam turbines 5 and 6 are stopped. .

  According to the control at the time of abnormality described above, the same valve that operates in the valve closing direction with respect to both the steam control valves 32 and 34 when the steam pressure becomes lower than the limit pressure in the high pressure limit pressure control and the intermediate pressure limit pressure control. The opening command value is output at the same time. When such control is performed, steam is supplied to either one of the steam turbines 5 and 6 while the pressure of the steam is reduced, and driving of each steam turbine 5 and 6 is continued. Can be prevented. As a result, it is possible to avoid the occurrence of overheating due to the stirring loss in the steam turbines 5 and 6 in which the steam pressure is reduced.

  Further, in the control at the time of abnormality described above, the valve opening command value is compared with the permitted opening, and it is determined whether or not the control at that time is continued, or in the high pressure limit pressure control and the intermediate pressure limit pressure control. After a predetermined determination time, it is determined whether the steam turbines 5 and 6 are to be stopped or operated normally. In other words, before stopping the steam turbines 5 and 6, it is possible to earn time for dealing with troubles and the like, and it is possible to take measures to continue driving the steam turbines 5 and 6 as much as possible.

  Further, by performing the control at the time of abnormality described above, in the plurality of steam turbines 5 and 6 driven by the first and second flashers 3 and 4 which are different steam sources, due to the stirring loss of any of the steam turbines 5 and 6 Normal operations such as pre-pressure control and output control corresponding to different steam sources can be smoothly performed while preventing heat generation.

  By the way, in a steam turbine facility, a technique for preventing heat generation due to a stirring loss at an extremely low flow rate is known (see Japanese Patent No. 4973583). In the steam turbine equipment of this publication, the exhaust gas from the high-pressure turbine section is introduced into the low-pressure turbine section via a moisture separator, and the pressure relief valve that releases the exhaust gas from the high-pressure turbine section is provided on the outlet side of the high-pressure turbine section. The loss is prevented. Therefore, the contents described in this publication are completely different in technical idea from the control in which the same valve opening command value is simultaneously output to the respective steam control valves 32 and 34 as in the present embodiment. .

  Further, as a technique for preventing the stir loss, a configuration in which a spray device that ejects cooling water is installed on the outlet side of the steam turbine is conceivable. However, the geothermal steam turbine equipment has a problem that the cooling water promotes erosion, corrosion due to impurities contained in the steam, stress corrosion cracking, and the like.

  Next, other embodiments of the present invention will be described. In the following description, the same reference numerals are used for the same or equivalent components as those described in the embodiment described before, and the description is omitted or simplified. In the following embodiments, a relatively low pressure will be described as “low pressure” with respect to “medium pressure”.

[Second Embodiment]
FIG. 8 is a schematic configuration diagram showing a part of the steam turbine equipment according to the second embodiment. As shown in FIG. 8, the steam turbine equipment 1 according to the second embodiment includes a low-pressure steam turbine (third steam turbine) 50. The low-pressure steam turbine 50 includes a casing in which steam is supplied, and steam is supplied from a third flasher (not shown) described later. Therefore, the steam turbine equipment 1 according to the second embodiment is a triple-flash three-casing geothermal turbine equipment.

  The low-pressure steam turbine 50 is driven by low-pressure steam whose pressure is lower than that of medium-pressure steam supplied via the low-pressure steam supply pipe 51. The low-pressure steam supplied to the low-pressure steam supply pipe 51 is supplied from a third flasher (not shown). The third flasher depressurizes the hot water supplied from the second flasher 4 (see FIG. 1), and the hot water Separated into lower temperature hot water and low pressure steam. The turbine rotor of the low-pressure steam turbine 50 includes a rotating shaft 52. One end side of the rotating shaft 52 is connected to the rotating shaft 27 of the intermediate pressure steam turbine 6, and they are simultaneously rotated at the same rotational speed in the same direction. Therefore, the low-pressure steam turbine 50, the intermediate-pressure steam turbine 6, and the high-pressure steam turbine 5 are connected in series. The other end side of the rotary shaft 27 in the low pressure steam turbine 50 is connected to the generator 8.

  The low-pressure steam supply pipe 51 is provided with a low-pressure steam stop valve 54, a low-pressure steam control valve 55, and a low-pressure vent valve (not shown). The low pressure steam stop valve 54 shuts off the steam introduced into the low pressure steam turbine 50. The low pressure steam control valve 55 adjusts the flow rate of the low pressure steam introduced into the low pressure steam turbine 50. The valve opening degree of the low-pressure steam control valve 55 is controlled via the control means 10 (see FIG. 1). The valve opening command value output from the control means 10 to the low pressure steam control valve 55 is the same as the valve opening command values for the high pressure steam control valve 32 and the intermediate pressure steam control valve 34 and is output simultaneously. In the low pressure steam control valve 55, the steam flow rate with respect to the valve opening command value is appropriately set according to various conditions of the steam turbine equipment 1. The low-pressure vent valve (not shown) opens when the pressure in the low-pressure steam supply pipe 51 exceeds a predetermined value, releases the low-pressure steam to the atmosphere, and closes when the pressure becomes lower than the predetermined value. Stop releasing.

  In the control of the steam turbine equipment 1 according to the second embodiment, the operation of the low pressure steam control valve 55 is the same as the operation of the intermediate pressure steam control valve 34.

[Third Embodiment]
FIG. 9 is a schematic configuration diagram showing a part of the steam turbine equipment according to the third embodiment. As shown in FIG. 9, the steam turbine equipment 1 according to the third embodiment supplies low-pressure steam to the high-pressure steam turbine 5 in addition to high-pressure steam. Therefore, the steam turbine equipment 1 according to the third embodiment is a triple-flash two-casing geothermal turbine equipment. In the casing of the high-pressure steam turbine 5, a low-pressure steam supply pipe 51 is connected to the downstream side of the connection position of the high-pressure steam supply pipe 14, and the low-pressure steam is inserted while the high-pressure steam flows.

  In the control of the steam turbine equipment 1 according to the third embodiment, the operation of the low-pressure steam control valve 55 is a pre-pressure that controls the pressure of the low-pressure steam in the low-pressure steam supply pipe 51 regardless of the characteristic table of FIG. Control is performed. However, the low-pressure steam control valve 55 is closed under the condition that the valve opening command value of the high-pressure steam control valve 32 is equal to or greater than a predetermined specified value and the output power value of the generator 8 is equal to or greater than the predetermined specified value. The valve state is released. Thereby, it is possible to avoid the supply of the low pressure steam from the low pressure steam supply pipe 51 without being supplied with the high pressure steam from the high pressure steam supply pipe 14, and on the upstream side from the connection position of the low pressure steam supply pipe 51 serving as the low pressure steam inlet. Heat generation due to stirring loss can be prevented.

[Fourth Embodiment]
FIG. 10 is a schematic configuration diagram showing a part of the steam turbine equipment according to the fourth embodiment. As shown in FIG. 10, the steam turbine equipment 1 according to the fourth embodiment supplies low pressure steam to the intermediate pressure steam turbine 6 in addition to the intermediate pressure steam. Therefore, the steam turbine equipment 1 according to the fourth embodiment is a triple-flash type two-casing geothermal turbine equipment. In the casing of the intermediate pressure steam turbine 6, a low pressure steam supply pipe 51 is connected to the downstream side of the connection position of the intermediate pressure steam supply pipe 22, and the low pressure steam is inserted while the intermediate pressure steam flows.

  In the control of the steam turbine equipment 1 according to the fourth embodiment, the operation of the low-pressure steam control valve 55 is the pre-pressure for controlling the pressure of the low-pressure steam in the low-pressure steam supply pipe 51 regardless of the characteristic table of FIG. Control is performed. However, under the condition that the valve opening command value of the intermediate pressure steam control valve 34 is not less than a predetermined specified value and the output power value of the generator 8 is not less than the predetermined specified value, the low pressure steam control valve 55 is The valve is released from the closed state. As a result, it is possible to avoid the supply of low pressure steam from the low pressure steam supply pipe 51 without supply of intermediate pressure steam from the intermediate pressure steam supply pipe 22, and upstream from the connection position of the low pressure steam supply pipe 51 serving as the low pressure steam inlet. Heat generation due to stirring loss on the side can be prevented.

[Fifth Embodiment]
FIG. 11 is a schematic configuration diagram showing a part of the steam turbine equipment according to the fifth embodiment. As shown in FIG. 11, the steam turbine equipment 1 according to the fifth embodiment omits the intermediate-pressure steam turbine 6 (see FIG. 8) from the steam turbine equipment 1 according to the second embodiment, and has a high pressure. In addition to the high-pressure steam, medium-pressure steam is supplied to the steam turbine 5. Therefore, the steam turbine equipment 1 according to the fifth embodiment is a triple-flash type two-casing geothermal turbine equipment. In the casing of the high-pressure steam turbine 5, an intermediate-pressure steam supply pipe 22 is connected to the downstream side of the connection position of the high-pressure steam supply pipe 14, and the intermediate-pressure steam is inserted in the middle of the flow of high-pressure steam.

  In the control of the steam turbine equipment 1 according to the fifth embodiment, the same control is performed by replacing the relationship between the intermediate pressure steam control valve 34 and the low pressure steam control valve 55 with respect to the third embodiment. Can do. However, under the condition that the valve opening command value of the high-pressure steam control valve 32 is not less than a predetermined specified value and the output power value of the generator 8 is not less than the predetermined specified value, the intermediate pressure steam control valve 34 is The valve is released from the closed state. Accordingly, it is possible to avoid the supply of the intermediate pressure steam from the intermediate pressure steam supply pipe 22 without the supply of the high pressure steam from the high pressure steam supply pipe 14, and the connection position of the intermediate pressure steam supply pipe 22 serving as the intermediate pressure steam inlet It is possible to prevent heat generation due to stirring loss more upstream.

[Sixth Embodiment]
FIG. 12 is a schematic configuration diagram showing a part of the steam turbine equipment according to the sixth embodiment. As shown in FIG. 12, the steam turbine equipment 1 according to the sixth embodiment is provided with a bypass pipe 70 with respect to the steam turbine equipment 1 (see FIG. 1) of the first embodiment. One end side of the bypass pipe 70 is connected to the downstream side of the high-pressure steam control valve 32 of the high-pressure steam supply pipe 14. The other end side of the bypass pipe 70 is connected to the downstream side of the intermediate pressure steam control valve 34 of the intermediate pressure steam supply pipe 22. Therefore, the high-pressure steam supply pipe 14 and the intermediate-pressure steam supply pipe 22 communicate with each other via the bypass pipe 70. The bypass pipe 70 is provided with a steam cutoff valve 71 that blocks the flow of steam through the bypass pipe 70. The steam shut-off valve 71 is controlled to open and close via the control means 10 (see FIG. 1).

  In the sixth embodiment, the abnormal operation in which the pressure of the high-pressure steam or the medium-pressure steam is suddenly decreased is a control obtained by changing a part of the control in the first embodiment. When the high-pressure steam pressure suddenly drops, ST201 (see FIG. 4) in the pattern (2) and ST301 (see FIG. 5) in the pattern (3) are changed. In place of these ST201 and ST301, in the sixth embodiment, when the pressure value detected by the high pressure detector 42 (see FIG. 1) reaches a preset lower limit value, the high pressure steam control valve 32 is opened. A command to completely close the high-pressure steam control valve 32 is output after being disconnected from the control by the degree command value. In the case of the pattern (1), patterns corresponding to the pattern ST201 of (2) and the pattern ST301 of (3) are added.

  After the high-pressure steam control valve 32 is fully closed, a command to open the steam cutoff valve 71 is output. Then, the intermediate pressure steam supplied from the intermediate pressure steam supply pipe 22 is supplied not only to the intermediate pressure steam turbine 6 but also from the bypass pipe 70 to the high pressure steam turbine 5 through the high pressure steam supply pipe 14.

  When the intermediate pressure steam pressure is suddenly reduced, ST407 (see FIG. 6) in the patterns (1) and (2) and ST501 (see FIG. 7) in the pattern (3) are changed. Instead of these ST407 and ST501, in the sixth embodiment, when the pressure value detected by the intermediate pressure detector 43 reaches a preset lower limit value, the intermediate pressure steam control valve 34 is set to the valve opening command value. A command to completely close the intermediate pressure steam control valve 34 is output from the control by the control.

  After the intermediate pressure steam control valve 34 is fully closed, a command to open the steam cutoff valve 71 is output. Then, the high pressure steam supplied from the high pressure steam supply pipe 14 is supplied not only to the high pressure steam turbine 5 but also from the bypass pipe 70 to the intermediate pressure steam turbine 6 through the intermediate pressure steam supply pipe 22.

  As described above, even when the pressure drop of the supplied steam is continued, the steam is supplied to both the steam turbines 5 and 6 through the bypass pipe 70 from the steam supply pipes 14 and 22 where the steam pressure is not reduced. can do. As a result, although there are some restrictions, in the first embodiment, the driving of the steam turbines 5 and 6 can be stopped even in a situation where the driving of the steam turbines 5 and 6 must be stopped. Can be suppressed.

[Seventh Embodiment]
FIG. 13 is a schematic configuration diagram showing a part of the steam turbine equipment according to the seventh embodiment. As shown in FIG. 13, the steam turbine equipment 1 according to the seventh embodiment is different from the steam turbine equipment 1 of the second embodiment (see FIG. 8) in the first bypass pipe 73 and the second bypass pipe. 74 is provided. The first bypass pipe 73 communicates with the high-pressure steam supply pipe 14 and the intermediate-pressure steam supply pipe 22 in the same manner as the bypass pipe 70 of the seventh embodiment. One end side of the second bypass pipe 74 is connected to the downstream side of the intermediate pressure steam control valve 34 of the intermediate pressure steam supply pipe 22. The other end side of the second bypass pipe 74 is connected to the downstream side of the low pressure steam control valve 55 of the low pressure steam supply pipe 51. Accordingly, the intermediate pressure steam supply pipe 22 and the low pressure steam supply pipe 51 are in communication with each other via the second bypass pipe 74. The first bypass pipe 73 is provided with a first steam cutoff valve 75 that blocks the flow of steam through the first bypass pipe 73. The second bypass pipe 74 is provided with a second steam cutoff valve 76 that blocks the flow of steam through the second bypass pipe 74. Opening / closing of each of the steam shut-off valves 75 and 76 is controlled via the control means 10 (see FIG. 1).

  In the seventh embodiment, the second steam cutoff valve 76 remains closed with respect to the control of the abnormal operation in which the pressure of the high-pressure steam or the medium-pressure steam is suddenly reduced. Further, the control of the steam control valves 32 and 34 and the first steam cutoff valve 75 is the same as the control of the steam control valves 32 and 34 and the steam cutoff valve 70 of the seventh embodiment.

  In the seventh embodiment, the control when the low-pressure steam suddenly drops or two of the high-pressure, medium-pressure, and low-pressure steam suddenly fall and reach the lower limit value is as follows. Become.

  When the pressure of the low-pressure steam reaches the lower limit value, control is performed to fully close the low-pressure steam control valve 55 and open the second steam cutoff valve 76. Accordingly, the intermediate pressure steam is supplied not only to the intermediate pressure steam turbine 6 but also to the low pressure steam turbine 50 through the second bypass pipe 74, and the driving of the low pressure steam turbine 50 is continued.

  When the pressures of the high-pressure steam and the intermediate-pressure steam reach the lower limit values, the high-pressure steam control valve 32 and the intermediate-pressure steam control valve 34 are fully closed, and the first and second steam shut-off valves 75 and 76 are opened. I do. As a result, the low-pressure steam is supplied not only to the low-pressure steam turbine 50 but also to the high-pressure steam turbine 5 and the intermediate-pressure steam turbine 6 through the first and second bypass pipes 73 and 74, and the driving of the steam turbines 5 and 6 is continued. Is done.

  When the pressure of the high-pressure steam and the low-pressure steam reaches the lower limit value, the high-pressure steam control valve 32 and the low-pressure steam control valve 55 are fully closed, and the first and second steam shut-off valves 75 and 76 are opened. . Thereby, the intermediate pressure steam is supplied not only to the intermediate pressure steam turbine 6 but also to the high pressure steam turbine 5 and the low pressure steam turbine 50 through the first and second bypass pipes 73 and 74, and the driving of the steam turbines 5 and 50 is performed. Will continue.

  When the pressures of the medium-pressure steam and the low-pressure steam reach the lower limit values, the intermediate-pressure steam control valve 34 and the low-pressure steam control valve 55 are fully closed, and the first and second steam shut-off valves 75 and 76 are opened. I do. As a result, the high-pressure steam is supplied not only to the high-pressure steam turbine 5 but also to the intermediate-pressure steam turbine 6 and the low-pressure steam turbine 50 through the first and second bypass pipes 73 and 74, and the driving of the steam turbines 6 and 50 is continued. Is done.

[Eighth Embodiment, Ninth Embodiment]
FIG. 14 is a schematic configuration diagram showing a part of the steam turbine equipment according to the eighth embodiment. As shown in FIG. 14, the steam turbine equipment 1 according to the eighth embodiment changes the connection position of the second bypass pipe 74 with respect to the steam turbine equipment 1 (see FIG. 13) of the seventh embodiment. It is a thing. One end side of the second bypass pipe 74 is connected to the downstream side of the high-pressure steam control valve 32 of the high-pressure steam supply pipe 14, and the other end side is connected to the downstream side of the low-pressure steam control valve 55 of the low-pressure steam supply pipe 51. .

  FIG. 15 is a schematic configuration diagram showing a part of the steam turbine equipment according to the ninth embodiment. As shown in FIG. 15, the steam turbine equipment 1 according to the ninth embodiment changes the connection position of the first bypass pipe 73 with respect to the steam turbine equipment 1 (see FIG. 13) of the seventh embodiment. It is a thing. One end side of the first bypass pipe 73 is connected to the downstream side of the high pressure steam control valve 32 of the high pressure steam supply pipe 14, and the other end side is connected to the downstream side of the low pressure steam control valve 55 of the low pressure steam supply pipe 51. .

  In the eighth and ninth embodiments, when the pressure of any one or two of the high pressure, medium pressure, and low pressure steam suddenly drops and reaches the lower limit value, the steam with the reduced pressure flows. The steam control valves 32, 34 and 55 are fully closed. Then, control is performed to open the steam cutoff valves 75 and 76 of the bypass pipes 73 and 74 connected to the steam supply pipes 14, 22 and 51 through which the rapidly reduced pressure flows. As a result, the steam is supplied to all the steam turbines 5, 6, 50 and the driving is continued.

[Tenth Embodiment, Eleventh Embodiment]
FIG. 16 is a schematic configuration diagram illustrating a part of the steam turbine equipment according to the tenth embodiment. As shown in FIG. 16, the steam turbine equipment 1 according to the tenth embodiment is provided with a bypass pipe 70 with respect to the steam turbine equipment 1 (see FIG. 9) of the third embodiment. One end side of the bypass pipe 70 is connected to the downstream side of the high pressure steam control valve 32 of the high pressure steam supply pipe 14, and the other end side is connected to the downstream side of the medium pressure steam control valve 34 of the intermediate pressure steam supply pipe 22. . The bypass pipe 70 is provided with a steam cutoff valve 71 that blocks the flow of steam through the bypass pipe 70.

  FIG. 17 is a schematic configuration diagram showing a part of the steam turbine equipment according to the eleventh embodiment. As shown in FIG. 17, the steam turbine equipment 1 according to the eleventh embodiment is provided with a bypass pipe 70 with respect to the steam turbine equipment 1 according to the fourth embodiment (see FIG. 10). One end side of the bypass pipe 70 is connected to the downstream side of the high pressure steam control valve 32 of the high pressure steam supply pipe 14, and the other end side is connected to the downstream side of the medium pressure steam control valve 34 of the intermediate pressure steam supply pipe 22. . The bypass pipe 70 is provided with a steam cutoff valve 71 that blocks the flow of steam through the bypass pipe 70.

  In the tenth and eleventh embodiments, when the pressure of the high-pressure steam or the medium-pressure steam suddenly decreases and reaches the lower limit value, the control of each of the steam control valves 32 and 34 and the steam shut-off valve 71 is the sixth control. This is the same as the control of the steam control valves 32 and 34 and the steam shut-off valve 71 in the embodiment.

[Twelfth embodiment]
FIG. 18 is a schematic configuration diagram showing a part of the steam turbine equipment according to the twelfth embodiment. As shown in FIG. 18, the steam turbine equipment 1 according to the twelfth embodiment is provided with a bypass pipe 70 with respect to the steam turbine equipment 1 (see FIG. 11) of the fifth embodiment. One end side of the bypass pipe 70 is connected to the downstream side of the high-pressure steam control valve 32 of the high-pressure steam supply pipe 14, and the other end side is connected to the downstream side of the low-pressure steam control valve 55 of the low-pressure steam supply pipe 51. The bypass pipe 70 is provided with a steam cutoff valve 71 that blocks the flow of steam through the bypass pipe 70.

  In the twelfth embodiment, when the pressure of the high-pressure steam or the low-pressure steam rapidly decreases and reaches the lower limit value, the control of each of the steam control valves 32 and 55 and the steam cutoff valve 71 is performed in the sixth embodiment. By switching the relationship between the intermediate pressure steam control valve 34 and the low pressure steam control valve 55, the same control can be performed.

  In addition, this invention is not limited to the said embodiment, It can implement variously. In the above-described embodiment, the size, shape, direction, and the like illustrated in the accompanying drawings are not limited thereto, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, the number of installed steam turbines is not limited to two or three, and more steam turbines may be installed.

  Further, the present invention is not limited to a configuration in which a plurality of steam turbines are individually provided with casings, and a plurality of steam turbines are provided with an intermediate seal portion interposed between the steam seals. Turbine sections (for example, a high-pressure turbine section, an intermediate-pressure turbine section, and a low-pressure turbine section) may be provided.

  Moreover, although the load connected to the steam turbines 5, 6, and 50 is the generator 8 in each of the above embodiments, the load is not limited to this and may be connected to a compressor, a blower, or the like.

  Further, the steam turbines 5, 6, 50 in each of the above embodiments may be changed to a twin flow turbine instead of the single flow turbine.

1 Steam turbine equipment 3 First flasher (steam source)
4 Second flasher (steam source)
DESCRIPTION OF SYMBOLS 5 High pressure steam turbine 6 Medium pressure steam turbine 10 Control means 10c Characteristic table 32 High pressure steam control valve 34 Medium pressure steam control valve 42 High pressure detector (pressure detector)
43 Medium pressure detector (pressure detector)
50 Low pressure steam turbine 55 Low pressure steam control valve

Claims (9)

A plurality of steam turbines connected in series driven by steam supplied from different steam sources; a steam control valve provided in each of the plurality of steam turbines to adjust the flow rate of steam supplied from the steam sources; Steam turbine equipment comprising control means for controlling the operation of the steam control valve by the output of a valve opening command value,
The said control means outputs the said valve opening degree command value of the same value simultaneously with respect to the said some steam control valve, The steam turbine equipment characterized by the above-mentioned.   The control means includes a characteristic table in which a relationship between the steam flow rates of the plurality of steam control valves with respect to the valve opening command value is set, and the valve opening command value is obtained with reference to the characteristic table. The steam turbine equipment according to claim 1, wherein   The characteristic table sets an upper limit setting value of the valve opening command value in relation to the steam flow rate and the valve opening command value in at least one of the steam control valves, and a valve opening command equal to or higher than the upper setting value. 3. The steam turbine equipment according to claim 2, wherein the steam flow rate is a constant value.   The steam turbine equipment according to claim 3, wherein the control means outputs an additional valve opening command value for increasing a steam flow rate from the constant value to the steam control valve for which the upper limit set value is set. .   5. The apparatus according to claim 1, further comprising: a bypass pipe connecting downstream sides of the plurality of steam control valves; and a steam cutoff valve capable of shutting off a flow of steam in the bypass pipe. Steam turbine equipment according to the above. A pressure detector for detecting the pressure value of the steam is provided on the upstream side of each of the plurality of steam control valves;
6. The control means according to claim 1, wherein the control means determines the pressure value of the pressure detector by comparing with a specified value, and outputs the valve opening command value based on the determination result. The steam turbine equipment described in any one. A plurality of steam turbines connected in series driven by steam supplied from different steam sources, and a steam control valve provided in each of the plurality of steam turbines for adjusting and adjusting the steam supplied from the steam sources. A control method for steam turbine equipment,
Steam turbine equipment characterized by simultaneously outputting valve opening command values having the same value to the plurality of steam control valves, and controlling the operations of the plurality of steam control valves by outputting the valve opening command values. Control method.   8. The plurality of steam control valves are simultaneously opened from a closed state by simultaneously outputting the valve opening command value having the same value when starting the plurality of steam turbines. Control method of steam turbine equipment.   When the pressure of the steam supplied to the plurality of steam turbines suddenly decreases, the valve opening command value having the same value is simultaneously output to simultaneously close the plurality of steam control valves. The control method of the steam turbine equipment according to claim 7 or 8.

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