JP6173711B2 - Steam turbine plant and operation method thereof - Google Patents

Description

  The present invention relates to a steam turbine plant that prevents water droplets such as drain water from entering a turbine casing when the steam turbine is started, and an operation method thereof.

  In a steam turbine plant such as a power plant, when steam generated in a boiler is supplied to the steam turbine to start the steam turbine, water drops enter the steam turbine due to several causes, and the surface of the turbine rotor and the turbine casing The inner surface of the steel may be cooled. As a result, the turbine rotor and the turbine casing may cause unequal deformation (local deformation) to induce critical vibrations or erosion, etc. It is necessary to prevent water droplets from entering as much as possible. The following four points can be cited as the main causes of water droplets entering the steam turbine.

(1) When steam is introduced into the main steam introduction line connecting the boiler and the steam turbine, the main steam introduction line is cold, so some steam condenses into drain water and becomes water droplets as it is. Enter the turbine.

(2) In order to prevent the event of (1), the main steam is discharged from the main steam bypass line branched from the main steam introduction line before the main steam is fed into the steam turbine when starting the steam turbine, and the condenser is To stabilize the temperature of the main steam introduction line. At this time, the curtain spray device provided in the condenser is operated in order to suppress the temperature rise and the vacuum level of the condenser, but the curtain spray water rolls up into water droplets and enters the steam turbine. End up.

(3) The drain water that is connected to the main steam introduction line and has accumulated near the shut-off valve of the auxiliary steam introduction line that adjusts the temperature of the main steam by introducing auxiliary steam at a lower temperature than the main steam to the main steam introduction line, At startup, the shut-off valve is opened and the main steam introduction line is entered, and water droplets enter the steam turbine.

(4) When the boiler is shut down, the main steam shut-off valve that supplies or shuts off the steam from the boiler to the main steam line is closed. If this main steam shut-off valve leaks slightly, The drain water stays on the upstream side of the main steam stop valve provided, and at the same time as the main steam stop valve opens, the drain water enters the main steam introduction line at the time of restart, and water drops enter the steam turbine.

  Conventionally, as disclosed in Patent Document 1, the height of the upper surface of the valve seat of the valve main body is higher than the lower end surface of the inlet of the valve so that drain water does not accumulate upstream of the main steam stop valve. Alternatively, there is a technique in which drain water in the vicinity of the valve seat is caused to flow toward the inlet side and is not accumulated in the vicinity of the valve seat by being positioned on the same horizontal plane.

Japanese Patent Laid-Open No. 11-343811

  However, with the technique disclosed in Patent Document 1, water droplets such as drain water cannot be reliably prevented from entering the turbine casing when the steam turbine is started. For this reason, the steam turbine could not be started up smoothly and in a short time. Moreover, in order to apply this technology, it is necessary to newly replace the existing main steam stop valve, and it is necessary to greatly change the configuration of the existing steam turbine plant.

  The present invention has been made in view of the above circumstances, and water droplets such as drain water enter the turbine casing when starting up and operating the steam turbine without greatly changing the configuration of the existing steam turbine plant. It is an object of the present invention to provide a steam turbine plant and an operation method thereof that can prevent the occurrence of critical vibration and erosion at the start of the steam turbine, and can start the steam turbine smoothly and in a short time. To do.

In order to solve the above problems, the present invention employs the following means.
That is, a steam turbine plant according to the present invention includes a boiler that generates main steam, a steam turbine that is rotationally driven by the main steam, a main steam cutoff valve and a governor valve that convert the main steam generated by the boiler. A main steam introduction line for supplying to the steam turbine via, a condenser for condensing the main steam after the rotation of the steam turbine has been completed, and a curtain spray for spraying curtain spray water inside the condenser A main steam bypass that branches from the upstream side of the governor valve of the main steam introduction line, bypasses the steam turbine, and connects to the condenser A main steam bypass valve provided in the main steam bypass line, and when the steam turbine is started, the main steam shut-off valve is opened, and the governor With the valve closed, the main steam bypass valve is opened, and flows through the main steam introduction line until the temperature measured by the temperature measuring means of the main steam introduction line to the governor valve is stabilized. Main steam flows from the main steam bypass line to the condenser, and after the temperature of the main steam introduction line is stabilized, the governor valve is opened to supply the main steam to the steam turbine and the main steam bypass. Start control means for closing the valve, and the start control means includes the main steam shut-off valve and the main steam bypass valve after the curtain spray device is operated when the steam turbine is started. It is characterized by being opened .

  According to the steam turbine plant having the above configuration, when the steam turbine is started, the main steam supplied from the boiler passes through the bypass line from the main steam and condensates until the temperature of the cooled main steam introduction line is stabilized. Washed away in a bowl. As a result, while the main steam introduction line is cooled, the drain water generated by the condensation of the main steam in the main steam introduction line flows along with the main steam from the bypass line to the condenser. It is prevented from entering the steam turbine. Accordingly, it is possible to start up the steam turbine smoothly and in a short time by suppressing the occurrence of critical vibration, erosion, and the like at the start of the steam turbine.

Further, conventionally, since the curtain spray device is operated after receiving the opening signal of the bypass valve for opening the bypass line, the condenser is heated by the high-temperature main steam (about 200 ° C.) flowing through the bypass line. As the low temperature curtain spray water is sprayed there, the curtain spray water scatters and rolls up due to a large temperature difference, adheres to the rotor and the passenger compartment of the steam turbine, and the above-mentioned critical vibration and erosion, etc. There was a concern to generate. In addition, the condenser may be damaged.

On the other hand, in the present invention, the activation control means opens the bypass line after operating the curtain spray device. The temperature of the curtain spray water is much lower than the temperature of the main steam (for example, about 40 ° C). Under the condition that this curtain spray water is sprayed inside the condenser, Since the high-temperature main steam is supplied, the curtain spray water is prevented from boiling and splashing violently at the moment when the curtain spray water touches the high-temperature main steam inside the condenser as in the prior art.
For this reason, curtain spray water does not roll up from the condenser to the steam turbine side, and water can be prevented from entering the rotor and the passenger compartment of the steam turbine. And generation | occurrence | production of the critical vibration, erosion, etc. at the time of starting of a steam turbine can be suppressed, and a steam turbine can be started up smoothly and in a short time. Furthermore, the condenser can be prevented from being deteriorated or damaged by thermal shock.

  The present invention only changes the timing of spraying the curtain spray water inside the condenser at the start of the steam turbine from the opening of the bypass line to the opening of the bypass line. This can be easily implemented by changing the program of the control device without changing the configuration.

The steam turbine plant according to the present invention includes a boiler that generates main steam, a steam turbine that is rotationally driven by the main steam, the main steam generated by the boiler, a main steam cutoff valve, and a governor valve. A main steam introduction line that supplies the steam turbine via the main steam, a main steam water droplet detection unit that senses that there is a water droplet upstream of the main steam shutoff valve of the main steam introduction line, and the main steam introduction A main steam drain valve that discharges the water droplets from the line, a condenser that condenses the main steam that has been driven to rotate the steam turbine, and a curtain spray device that sprays curtain spray water into the condenser. A main steam bypass line that branches from the upstream side of the governor valve of the main steam introduction line, bypasses the steam turbine and connects to the condenser, and the main steam bypass A main steam bypass valve provided in Surain, during startup of the steam turbine, if there is an input of the water droplet sensing signal from the main steam water droplet sensing portion, the water drops temporarily opened the main steam drain valve Start control means for opening the main steam shut-off valve after discharging and supplying the main steam to the steam turbine, and the start control means is configured to use the curtain spray device when the steam turbine is started. The main steam shut-off valve and the main steam bypass valve are opened after actuating the valve .

  According to the steam turbine plant configured as described above, when there are water droplets such as drain water in the main steam introduction line, a water droplet detection signal is output from the main steam water droplet sensing unit to the activation control unit, and in response to this, the activation control unit Supplies the main steam to the steam turbine after temporarily opening the main steam drain valve to discharge water droplets. For this reason, it is prevented that a steam turbine starts and a water droplet enters a turbine vehicle interior, with a water droplet remaining in the main steam introduction line.

Further, a steam turbine plant according to the present invention includes a boiler that generates main steam, a steam turbine that is rotationally driven by the main steam, a main steam cutoff valve and a governor valve that convert the main steam generated by the boiler. A main steam introduction line for supplying to the steam turbine via, a condenser for condensing the main steam after the rotation of the steam turbine has been completed, and a curtain spray for spraying curtain spray water inside the condenser An apparatus, a main steam bypass line branched from the upstream side of the governor valve of the main steam introduction line, bypassing the steam turbine and connected to the condenser, and a main steam bypass provided in the main steam bypass line a valve, a low-temperature auxiliary steam than the main steam, the auxiliary steam introduction line via an auxiliary steam gate valve is introduced into the main steam introduction line, the main steam An auxiliary steam bypass line that branches off from the introduction line and bypasses the steam turbine and connects to the condenser, an auxiliary steam bypass valve provided in the auxiliary steam bypass line, and water drops on the auxiliary steam introduction line Auxiliary steam / water droplet detection unit for detecting the water vapor, and the auxiliary steam gate valve is opened to introduce auxiliary steam from the auxiliary steam introduction line into the main steam introduction line, and at this time, the auxiliary steam / water droplet detection unit detects water droplets. If there is a signal input, the auxiliary steam bypass valve is opened, and start control means for causing the auxiliary steam flowing through the main steam introduction line to flow from the auxiliary steam bypass line to the condenser until the water droplets disappear. , comprising a, the start control means, when starting the steam turbine, the said main steam isolation valve after actuating the said curtain spray device Characterized by comprising by opening the steam bypass valve.

  According to the steam turbine plant configured as described above, when there is a water droplet such as drain water in the auxiliary steam introduction line, a water droplet detection signal is output from the auxiliary steam water droplet sensing unit to the activation control unit, and the activation control unit is received in response thereto. Opens the auxiliary steam gate valve, opens the auxiliary steam bypass valve of the auxiliary steam bypass line, and passes the auxiliary steam flowing through the main steam introduction line from the auxiliary steam bypass line to the condenser until water drops disappear. Shed. For this reason, the auxiliary steam introduced into the steam turbine from the main steam introduction line does not contain water droplets, thereby preventing the water droplets from entering the turbine casing.

The steam turbine plant operating method according to the present invention includes a boiler that generates main steam, a steam turbine that is rotationally driven by the main steam, a main steam cutoff valve, and a governor that converts the main steam generated by the boiler. A main steam introduction line that supplies the steam turbine via a valve, a condenser that condenses the main steam that has been driven to rotate the steam turbine, and spray spray water inside the condenser. Curtain spray device, temperature measuring means for measuring the temperature of the main steam introduction line, branch from the upstream side of the governor valve of the main steam introduction line, bypass the steam turbine and connect to the condenser A steam turbine plant operating method comprising: a main steam bypass line; and a main steam bypass valve provided in the main steam bypass line, When the steam turbine is started, the main steam shut-off valve is opened and the governor valve is closed, the main steam bypass valve is opened, and the temperature of the main steam introduction line to the governor valve is increased. The main steam flowing through the main steam introduction line is caused to flow from the main steam bypass line to the condenser until the temperature measured by the measuring means is stabilized, and the governor valve is turned on after the temperature of the main steam introduction line is stabilized. Opening the valve to supply the main steam to the steam turbine and closing the main steam bypass valve; and, when starting the steam turbine, after operating the curtain spray device, And a step of opening the main steam bypass valve .

  According to the operation method of the above steam turbine plant, when the main steam introduction line is cooled at the time of starting the steam turbine, the drain water generated by condensation of the main steam in the main steam introduction line is the main steam. In addition, since it flows from the bypass line to the condenser, the drain water is prevented from entering the steam turbine, thereby suppressing the occurrence of critical vibration and erosion at the start of the steam turbine. Start up smoothly and in a short time.

Also, with such an operation method, since the start control means opens the bypass line after the curtain spray device is operated, the curtain spray water is added to the condenser which has been heated by the heat of the main steam as in the prior art. Curtain spray water is prevented from boiling and splashing violently at the moment of touch. For this reason, it is possible to prevent water from entering the rotor and the passenger compartment of the steam turbine due to the curtain spray water roll-up, and it is possible to suppress the occurrence of critical vibration, erosion, etc. when the steam turbine is started.

The steam turbine plant operating method according to the present invention includes a boiler that generates main steam, a steam turbine that is rotationally driven by the main steam, the main steam generated by the boiler, and a main steam cutoff valve . A main steam introduction line that supplies the steam turbine via a governor valve, a main steam water drop detection unit that senses that there is a water drop upstream of the main steam cutoff valve of the main steam introduction line, and A main steam drain valve that discharges the water droplets from the main steam introduction line, a condenser that condenses the main steam that has finished rotating the steam turbine, and a curtain that sprays curtain spray water inside the condenser A main steam bypass line that branches from an upstream side of the governor valve of the main steam introduction line, bypasses the steam turbine, and is connected to the condenser; A main steam bypass valve provided in the steam bypass line, a method of operating a steam turbine plant consisting comprises a, at the start of the steam turbine, if there is an input of the water droplet sensing signal from the main steam water drops sensing unit A step of temporarily opening the main steam drain valve to discharge the water droplets and then opening the main steam shut-off valve to supply the main steam to the steam turbine; and at the time of starting the steam turbine And opening the main steam shut-off valve and the main steam bypass valve after operating the curtain spray device .

  According to the operation method of the steam turbine plant described above, when there are water droplets such as drain water in the main steam introduction line, a water droplet detection signal is output from the main steam water droplet detection unit. The main steam is supplied to the steam turbine after the water droplets are discharged. For this reason, it is prevented that a steam turbine starts and a water droplet enters a turbine vehicle interior, with a water droplet remaining in the main steam introduction line.

The steam turbine plant operating method according to the present invention includes a boiler that generates main steam, a steam turbine that is rotationally driven by the main steam, a main steam cutoff valve, and a governor that converts the main steam generated by the boiler. A main steam introduction line that supplies the steam turbine via a valve, a condenser that condenses the main steam that has been driven to rotate the steam turbine, and spray spray water inside the condenser. Curtain spray device, a main steam bypass line that branches from the upstream side of the governor valve of the main steam introduction line, bypasses the steam turbine and connects to the condenser, and is provided in the main steam bypass line a main steam bypass valve, the low-temperature auxiliary steam than the main steam, the auxiliary steam introduction line via an auxiliary steam gate valve is introduced into the main steam introduction line An auxiliary steam bypass line that branches off from the main steam introduction line and bypasses the steam turbine and connects to the condenser, an auxiliary steam bypass valve provided in the auxiliary steam bypass line, and water droplets on the auxiliary steam introduction line And an auxiliary steam water drop sensing unit for sensing the presence of the steam, and a steam turbine plant operating method comprising: opening the auxiliary steam gate valve and supplying the auxiliary steam from the auxiliary steam introduction line to the main steam. When the water droplet detection signal is input from the auxiliary steam water droplet detection unit during introduction into the introduction line, the auxiliary steam bypass valve is opened to flow through the main steam introduction line until the water droplets disappear. a step of flowing the condenser from the auxiliary steam bypass line, at the time of startup of the steam turbine, after actuation of the said curtain spray device Characterized in that it comprises a step for opening each and the main steam bypass valve and the main steam isolation valve.

  In the above steam turbine plant operation method, when there is water droplets such as drain water in the auxiliary steam introduction line, the auxiliary steam bypass valve is temporarily opened because the water droplet detection signal is input from the auxiliary steam water droplet sensor. The water vapor is discharged from the auxiliary steam bypass line to the condenser side and then the auxiliary steam is introduced into the main steam introduction line. For this reason, water droplets are not included in the auxiliary steam introduced into the main steam introduction line, thereby preventing water droplets from entering the turbine casing.

  Similarly to the main steam, the auxiliary steam bypass line is provided with temperature measuring means for measuring the temperature of the auxiliary steam introduction line, and when the steam turbine is started, the auxiliary steam cutoff valve is opened by the start control means. The auxiliary steam bypass valve is opened, and the auxiliary steam flowing through the auxiliary steam introduction line is allowed to flow from the auxiliary steam bypass line to the condensate until the temperature measured by the temperature measuring means of the auxiliary steam introduction line is stabilized. It may be operated to flow through a vessel.

  As described above, according to the steam turbine plant and the operation method thereof according to the present invention, the drain water or the like is placed in the turbine casing during startup and operation of the steam turbine without greatly changing the configuration of the existing steam turbine plant. It is possible to prevent water droplets from entering, suppress the occurrence of critical vibration and erosion at the start of the steam turbine, and start up the steam turbine smoothly and in a short time.

1 is a schematic configuration diagram of a steam turbine plant according to a first embodiment of the present invention. It is a flowchart which shows the operating method of the steam turbine plant which concerns on 1st Embodiment of this invention. It is a schematic block diagram of the steam turbine plant which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the structure of a main steam water droplet detection part and an auxiliary steam water droplet detection part. FIG.

  Hereinafter, two embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of a steam turbine plant according to a first embodiment of the present invention.
The steam turbine plant 1 is, for example, a thermal power plant, a waste heat recovery type boiler 2 that generates main steam, a steam turbine 3 that is driven by the main steam generated by the boiler 2, and a boiler 2. And a main steam introduction line 4 for connecting the main steam generated by the boiler 2 to the steam turbine 3. A generator 5 that receives power from the steam turbine 3 to generate power is installed.

  A condenser 7 is connected to the outlet side of the steam turbine 3 to rotate the rotor of the steam turbine 3 to condense the main steam whose pressure and temperature are reduced. The condenser 7 has a built-in cooling pipe 8 that is cooled by seawater or the like, and is further provided with a curtain spray device 9. The curtain spray device 9 is for spraying curtain spray water from above the cooling pipe 8 and is provided with an operating unit 10. Further, a condenser line 11 and a condensate pump 12 are connected to the condenser 7, and the condensate line 11 is connected to the boiler 2 side.

  Further, a main steam bypass line 13 branched from the main steam introduction line 4 and bypassing the steam turbine 3 and connected to the condenser 7 and an auxiliary steam introduction line 14 joining the main steam introduction line 4 are provided. Has been.

  The main steam introduction line 4 is provided with a main steam cutoff valve 16, a main steam stop valve 17, and a governor valve 18 in order from the boiler 2 side. The main steam bypass line 13 branches from the main steam introduction line 4 in a section between the main steam cutoff valve 16 and the main steam stop valve 17, and the auxiliary steam introduction line 14 is connected to the main steam cutoff valve 16 and the main steam stop valve 17. Is joined to the main steam introduction line 4 in the section between. The main steam bypass line 13 is provided with a main steam bypass valve 19, and the auxiliary steam introduction line 14 is provided with an auxiliary steam gate valve 20.

  Further, a control device 21 (starting control means) is provided for controlling the opening and closing of the valves 16, 17, 18, 19, 20 and for controlling the operating part 10 of the condenser 7. Further, a temperature measuring means 23 for measuring the temperature of the main steam introduction line 4 is provided. The temperature measuring unit 23 outputs temperature information of the main steam introduction line 4 to the control device 21.

The control device 21 controls the operation of the boiler 2 and the steam turbine 3 and closes the governor valve 18 and opens the main steam bypass valve 19 to open the main steam bypass line 13 when the steam turbine 3 is started. The main steam flowing through the main steam introduction line 4 is transferred from the main steam bypass line 13 to the condenser 7 until the temperature of the main steam introduction line 4 from 2 to the governor valve 18 becomes stable. Control flow.
At this time, it is preferable to control the curtain spray device 9 to operate before opening the main steam bypass valve 19 and to open the main steam bypass valve 19 thereafter.

  In the steam turbine plant 1 configured as described above, the main steam having a predetermined pressure generated in the boiler 2 and having a temperature of about 400 ° C. to 600 ° C. is opened by the main steam shut-off valve 16, the main steam stop valve 17, and the governor valve 18. By performing the valve operation, the steam is supplied to the steam turbine 3 through the main steam introduction line 4 and the rotor of the steam turbine 3 is rotationally driven. As a result, the generator 5 is rotated by receiving rotational power from the steam turbine 3 to generate power.

  The main steam, which has been expanded while rotationally driving the rotor of the steam turbine 3 and whose pressure and temperature have been reduced, flows into the condenser 7, where it condenses and becomes condensate by touching the cooling pipe 8. At this time, when the temperature of the condenser 7 rises and the pressure (vacuum degree) changes, the spraying of curtain spray water from the curtain spray device 9 promotes condensation of steam. The condensate flows along with the curtain spray water to the condensate line 11 and is returned to the boiler 2 by the condensate pump 12.

  For example, in order to reduce the load on the generator 5, the opening degree of the governor valve 18 is appropriately reduced in order to reduce the amount of main steam supplied from the boiler 2 to the steam turbine 3. When the temperature of the main steam supplied to the steam turbine 3 rises above a predetermined temperature, the auxiliary steam gate valve 20 is opened and the auxiliary steam is introduced from the auxiliary steam introduction line 14 to lower the main steam temperature. Alternatively, low-temperature auxiliary steam (about 200 ° C.) may be supplied to the main steam introduction line 4 and mixed with the main steam.

  Since the main steam introduction line 4 is cold when the steam turbine 3 is started, the main steam cutoff valve 16, the main steam stop valve 17, and the governor valve 18 are opened so that the main steam of the boiler 2 is supplied to the main steam introduction line 4. When the steam is supplied to the steam turbine 3, the drain water generated by condensation when the main steam touches the inner surface of the cold main steam introduction line 4 enters the steam turbine 3 together with the main steam. There is a risk of causing erosion or the like.

  Thus, in order to prevent water from entering the steam turbine 3 at the time of startup, the control device 21 controls each part as shown in the flowchart of FIG. That is, when the operation of the steam turbine plant 1 is started, the boiler 2 is first started (step S1), then the curtain spray device 9 is operated in the condenser 7 (step S2), and then the main steam introduction line is started. The main steam shut-off valve 16 and the main steam stop valve 17 are opened while the fourth governor valve 18 is closed (step S3).

  Next, the main steam bypass valve 19 is opened (step S4), and the hot main steam generated in the boiler 2 is caused to flow from the main steam bypass line 13 to the condenser 7. While the pipe temperature of the main steam introduction line 4 is low, drain water generated by condensation when the steam touches the pipe wall flows to the condenser 7 through the main steam bypass line 13 together with the main steam. Therefore, the drain water does not enter the steam turbine 3.

  When the high-temperature main steam of about 400 ° C. flowing through the main steam introduction line 4 flows into the condenser 7 via the main steam bypass line 13, curtain spray water in the condenser 7 in advance in step S 2. Spraying has begun. The temperature of the curtain spray water is much lower than the temperature of the main steam (for example, about 40 ° C.), and the curtain spray water is dispersed inside the condenser 7 under the condition that the curtain spray water is sprayed inside the condenser 7. High temperature main steam is put into the tank.

  Here, conventionally, the main steam bypass valve 19 is opened, and the curtain spray device 9 is operated after the high temperature main steam is introduced into the condenser 7 and the temperature and pressure of the condenser 7 are increased. Then, the main steam and curtain spray water touch inside the condenser 7 and the curtain spray water boils and scatters, and the curtain spray water enters the turbine rotor and turbine casing of the steam turbine 3 and is locally heated. The turbine rotor and the turbine casing may be deformed unequally (locally deformed) to induce critical vibrations or erosion.

  In the present embodiment, since the spray of curtain spray water in the condenser 7 has been started in advance in step S2 before the main steam flows into the condenser 7 via the main steam bypass line 13, The internal temperature of the water vessel 7 is sufficiently lowered, the curtain spray water is not scattered, and the curtain spray water can be prevented from entering the rotor of the steam turbine 3 or the passenger compartment. Further, the temperature rise and pressure (vacuum degree) change of the condenser 7 can be suppressed, and deterioration or breakage of the condenser 7 due to thermal shock can be prevented.

  Thus, while the main steam flows from the main steam bypass line 13 to the condenser 7, the temperature of the main steam introduction line 4 increases and stabilizes. The control device 21 determines whether or not the temperature of the main steam introduction line 4 is stable (step S5). If the temperature is not yet stable (step S5 → No), the above determination is repeated again. (Step S5 → Yes) The governor valve 18 is opened (Step S6), main steam is supplied to the steam turbine 3, and thereafter the main steam bypass valve 19 is closed in response to the opening of the governor valve 18 (Step S6). S7), the operation is continued.

  As described above, the steam turbine plant 1 and the operation method thereof according to the present embodiment open the main steam cutoff valve 16 and the main steam stop valve 17 before opening the governor valve 18 when the steam turbine 3 is started. At the same time, the main steam bypass valve 19 of the bypass line 13 is opened, and the main steam flowing through the main steam introduction line 4 is condensed from the main steam bypass line 13 until the temperature of the main steam introduction line 4 to the governor valve 18 is stabilized. After the temperature of the main steam introduction line 4 was stabilized, the governor valve 18 was opened to supply the main steam to the steam turbine 3.

  For this reason, while the main steam introduction line 4 is cooled, the drain water produced by the condensation of the main steam in the main steam introduction line 4 flows from the main steam bypass line 13 to the condenser 7 together with the main steam. This prevents the drain water from entering the steam turbine 3 as water droplets. Therefore, it is possible to start up the steam turbine 3 smoothly and in a short time by suppressing the occurrence of critical vibration, erosion and the like when the steam turbine 3 is started.

  In addition, the timing of spraying the curtain spray water inside the condenser 7 when the steam turbine 3 is started is changed from the opening of the main steam bypass line 13 to the opening of the main steam bypass line 13, so that the curtain spray water is on the steam turbine 3 side. It is possible to prevent the steam turbine 3 from jumping into the steam turbine 3, and also in this respect, the occurrence of critical vibration, erosion, etc. in the steam turbine 3 can be effectively suppressed.

  As described above, when the steam turbine 3 is started, the steam flowing through the main steam introduction line 4 is caused to flow to the main steam bypass line 13 until the temperature of the main steam introduction line 4 is stabilized, and the condenser 7 Since the timing of spraying the curtain spray water inside is simply changed from the opening of the main steam bypass line 13 to the opening of the main steam bypass line 13, the program of the control device can be executed without changing the configuration of the existing steam turbine plant. It can be easily implemented just by changing.

[Second Embodiment]
FIG. 3 is a schematic configuration diagram of a steam turbine plant according to the second embodiment of the present invention.
Since the basic configuration of the steam turbine plant 31 is the same as that of the steam turbine plant 1 in the first embodiment except for the additional points described below, the same portions are denoted by the same reference numerals and description thereof is omitted. The control of each unit by the control device 21 (startup control means) is the same as that of the first embodiment except for the control content described later.

  In the steam turbine plant 31, the main steam introduction line 4 is provided with a main steam water droplet detection unit 33 that detects the presence of water droplets inside the pipe. The main steam water droplet detection unit 33 is disposed, for example, immediately upstream of the main steam shut-off valve 16 where the steam flow is blocked and the drain water tends to accumulate. Further, a water droplet discharge pipe 34 branching from the vicinity of the main steam water droplet sensing unit 33 and immediately upstream of the main steam shutoff valve 16 is provided, and a main steam drain for discharging water droplets from the main steam introduction line 4 is provided at an intermediate portion thereof. A valve 35 is provided. When the main steam water droplet detection unit 33 detects a water droplet, the water droplet detection signal SIG. 1 is output to the control device 21.

  On the other hand, the auxiliary steam introduction line 14 is provided with an auxiliary steam water droplet detection unit 37 that detects the presence of water droplets therein. This auxiliary steam water droplet detection unit 37 is disposed immediately upstream of the auxiliary steam gate valve 20, for example, where the flow of steam is blocked and drain water is likely to accumulate. When the auxiliary steam water droplet detection unit 37 detects a water droplet, the water droplet detection signal SIG. 2 is output to the control device 21.

  Furthermore, an auxiliary steam bypass line 39 that branches from the main steam introduction line 4 and bypasses the steam turbine 3 and is connected to the condenser 7 is disposed. The auxiliary steam bypass line 39 is provided with an auxiliary steam bypass valve 40.

  In the steam turbine plant 31 configured as described above, the control device 21 receives the water drop detection signal SIG. From the main steam water drop detection unit 33 when the steam turbine 3 is started. 1 is input, the main steam drain valve 35 is temporarily opened before the main steam shutoff valve 16 is opened, and water droplets are discharged to the outside from the water droplet discharge pipe 34. Thereafter, the main steam drain valve 35 is opened. The main steam shut-off valve 16 is closed and control for introducing the main steam into the steam turbine 3 is performed.

  For this reason, when the main steam shut-off valve 16 is opened and the steam turbine 3 is started, the drain water accumulated immediately upstream of the main steam shut-off valve 16 is drained in advance. The main steam shut-off valve 16 is not opened with water droplets remaining, and water droplets are prevented from entering the turbine casing of the steam turbine 3.

  In addition, when the auxiliary steam is introduced from the auxiliary steam introduction line 14 into the main steam introduction line 4, the control device 21 receives the water drop detection signal SIG. If there is an input of 2, the main steam stop valve 17 is temporarily closed, the auxiliary steam gate valve 20 is opened, the auxiliary steam bypass valve 40 of the auxiliary steam bypass line 39 is opened, and the auxiliary steam is introduced. Control is performed so that auxiliary steam flowing through the main steam introduction line 4 is introduced into the auxiliary steam bypass line 39 until there is no water droplet in the line 14.

  Therefore, when the auxiliary steam gate valve 20 is opened and the auxiliary steam is introduced into the main steam introduction line 4, the drain water accumulated immediately upstream of the auxiliary steam gate valve 20 is discharged from the auxiliary steam bypass line 39 to the condenser. 7, the auxiliary steam introduced into the steam turbine 3 does not contain water droplets, thereby preventing the water droplets from entering the turbine casing of the steam turbine 3.

  As described above, the drain water collected immediately upstream of the main steam shutoff valve 16 and the drain water collected immediately upstream of the auxiliary steam gate valve 20 become water droplets as water droplets, and the turbine rotor and turbine vehicle of the steam turbine 3. It is prevented from adhering to the chamber and locally lowering the temperature, causing unequal deformation (local deformation) in the turbine rotor and the turbine casing to induce critical vibrations and to generate erosion and the like.

  FIG. 4 is a perspective view showing the structure of the main steam water droplet sensing unit 33 and the auxiliary steam water droplet sensing unit 37, and FIG. 5 is a view taken in the direction of arrow V in FIG. The main steam water droplet detection unit 33 and the auxiliary steam water droplet detection unit 37 are plugs that are airtightly screwed into female screw holes formed on the lower side in the vertical direction of the main steam introduction line 4 and the auxiliary steam introduction line 14. And includes a male screw part 41, a polygonal holding part 42 held by a spanner, a wrench or the like, and an insulating part 43 formed of ceramic or the like.

  On the top surface of the insulating portion 43, drain water detection terminals 44 and 45 made of a conductor which is not easily corroded, such as stainless steel, are installed. As shown in FIG. 5, the drain water detection terminals 44 and 45 are close to each other without being in contact with each other, and are configured to engage with each other so that the peripheral length becomes long even within a limited area of the insulating portion 43. , 45 is set to a size smaller than the diameter of the water droplets of the drain water, for example, about 1 mm. On the other hand, resistance measurement terminals 46 and 47 are projected from the outer surface of the holding portion 42 and are electrically connected to the drain water detection terminals 44 and 45 through lead wires 48 and 49, respectively. A resistance measurement portion 50 is connected to the resistance measurement terminals 46 and 47, and a resistance value between the drain water detection terminals 44 and 45 is measured here.

  The drain water detection terminals 44 and 45 are exposed on the inner surfaces of the main steam introduction line 4 and the auxiliary steam introduction line 14, and when water droplets of the drain water adhere thereto, the drain water detection terminals 44 and 45 are electrically connected by water drops. And the resistance value measured by the resistance measuring portion 50 is lowered. When the resistance value falls below a predetermined value, the water droplet detection signal SIG. 1 or SIG. 2 is output to the control device 21. Further, when the resistance measurement portion 50 senses a change in the current value without measuring the resistance value and exceeds a predetermined current value, the water droplet detection signal SIG. 1 or SIG. 2 may output to the control device 21.

  Incidentally, similarly to the temperature measuring means 23 for measuring the temperature of the steam introduction line 4, a temperature measuring means 52 for measuring the temperature of the auxiliary steam introduction line 14 is provided, and the auxiliary steam is shut off by the control device 21 when the steam turbine 3 is started. The valve 20 is opened, the auxiliary steam bypass valve 40 of the auxiliary steam bypass line 39 is opened, and the auxiliary steam bypass line 40 flows through the auxiliary steam introduction line 14 until the temperature measured by the temperature measuring means 52 of the auxiliary steam introduction line 14 is stabilized. The auxiliary steam may flow from the auxiliary steam bypass line 39 to the condenser 7.

  As described above, according to the steam turbine plants 1 and 31 and the operation method thereof according to the first and second embodiments, the startup of the steam turbine 3 can be performed without greatly changing the configuration of the existing steam turbine plant. Prevents water droplets such as drain water from entering the turbine casing during operation and operation, suppresses the occurrence of critical vibration and erosion when the steam turbine 3 is started, and makes the steam turbine 3 stand up smoothly and in a short time. Can be raised.

  It should be noted that the present invention is not limited to the configuration of the above-described embodiment, and can be appropriately modified or improved within a scope not departing from the gist of the present invention. Are also included in the scope of rights of the present invention.

For example, the branch position of the main steam bypass line 13 with respect to the main steam introduction line 4, the merge position of the auxiliary steam introduction line 14, or the branch position of the auxiliary steam bypass line 39 is merely an example. Changing to another position is also conceivable.
In addition, in the second embodiment (FIG. 3), the installation positions of the main steam water droplet detection unit 33, the water droplet discharge pipe 34, the main steam drain valve 35, the auxiliary steam water droplet detection unit 37, etc. are appropriately changed to other positions. Is possible.
Further, the auxiliary steam bypass line 39 in the second embodiment (FIG. 3) is formed as an independent route different from the main steam bypass line 13, but the main steam bypass line 13 is used as an auxiliary steam bypass line as necessary. It is good also as a structure shared.

1, 31 Steam turbine plant 2 Boiler 3 Steam turbine 4 Main steam introduction line 5 Generator 7 Condenser 9 Curtain spray device 13 Main steam bypass line 14 Auxiliary steam introduction line 16 Main steam shutoff valve 17 Main steam stop valve 18 Governor valve 19 Main steam bypass valve 20 Auxiliary steam gate valve 21 Control device (startup control means)
23 Temperature measuring means (for main steam)
33 Main Steam Water Drop Sensor 35 Main Steam Drain Valve 37 Auxiliary Steam Water Drop Sensor 39 Auxiliary Steam Bypass Line 40 Auxiliary Steam Bypass Valve 52 Temperature Measuring Means (for Auxiliary Steam)
SIG. 1, SIG. 2 Water drop detection signal

Claims (6)

A boiler that produces main steam;
A steam turbine rotationally driven by the main steam;
A main steam introduction line for supplying the main steam generated in the boiler to the steam turbine via a main steam cutoff valve and a governor valve;
A condenser for condensing the main steam that has finished rotating the steam turbine;
A curtain spray device for spraying curtain spray water inside the condenser;
Temperature measuring means for measuring the temperature of the main steam introduction line;
A main steam bypass line branched from the upstream side of the governor valve of the main steam introduction line, bypassing the steam turbine and connected to the condenser;
A main steam bypass valve provided in the main steam bypass line;
When starting the steam turbine, with the main steam shut-off valve opened and the governor valve closed, the main steam bypass valve is opened, and the main steam introduction line to the governor valve is opened. The governor valve flows after the main steam flowing through the main steam introduction line flows from the main steam bypass line to the condenser until the temperature measured by the temperature measuring means is stabilized, and the temperature of the main steam introduction line is stabilized. Starting control means for opening the valve and supplying the main steam to the steam turbine and closing the main steam bypass valve;
Equipped with,
The start control means opens the main steam cutoff valve and the main steam bypass valve after operating the curtain spray device when starting the steam turbine. A boiler that produces main steam;
A steam turbine rotationally driven by the main steam;
A main steam introduction line for supplying the main steam generated in the boiler to the steam turbine via a main steam cutoff valve and a governor valve ;
A main steam water droplet detection unit that senses that there is a water droplet upstream of the main steam shutoff valve of the main steam introduction line;
A main steam drain valve for discharging the water droplets from the main steam introduction line;
A condenser for condensing the main steam that has finished rotating the steam turbine;
A curtain spray device for spraying curtain spray water inside the condenser;
A main steam bypass line branched from the upstream side of the governor valve of the main steam introduction line, bypassing the steam turbine and connected to the condenser;
A main steam bypass valve provided in the main steam bypass line;
If a water droplet detection signal is input from the main steam water droplet detection unit at the time of starting the steam turbine, the main steam drain valve is temporarily opened to discharge the water droplets, and then the main steam cutoff valve is opened. Starting control means for supplying the main steam to the steam turbine by valve;
Equipped with,
The start control means opens the main steam cutoff valve and the main steam bypass valve after operating the curtain spray device when starting the steam turbine. A boiler that produces main steam;
A steam turbine rotationally driven by the main steam;
A main steam introduction line for supplying the main steam generated in the boiler to the steam turbine via a main steam cutoff valve and a governor valve ;
A condenser for condensing the main steam that has finished rotating the steam turbine;
A curtain spray device for spraying curtain spray water inside the condenser;
A main steam bypass line branched from the upstream side of the governor valve of the main steam introduction line, bypassing the steam turbine and connected to the condenser;
A main steam bypass valve provided in the main steam bypass line;
An auxiliary steam introduction line for introducing auxiliary steam having a temperature lower than that of the main steam to the main steam introduction line via an auxiliary steam gate valve;
An auxiliary steam bypass line that branches off from the main steam introduction line and bypasses the steam turbine and leads to the condenser;
An auxiliary steam bypass valve provided in the auxiliary steam bypass line;
An auxiliary steam water drop sensing unit for sensing the presence of water droplets in the auxiliary steam introduction line;
When the auxiliary steam gate valve is opened and auxiliary steam is introduced from the auxiliary steam introduction line into the main steam introduction line, and a water droplet detection signal is input from the auxiliary steam water droplet detection unit at that time, the auxiliary steam An activation control means for opening the bypass valve and flowing the auxiliary steam flowing through the main steam introduction line from the auxiliary steam bypass line to the condenser until the water droplets disappear.
Equipped with,
The start control means opens the main steam cutoff valve and the main steam bypass valve after operating the curtain spray device when starting the steam turbine. A boiler that produces main steam;
A steam turbine rotationally driven by the main steam;
A main steam introduction line for supplying the main steam generated in the boiler to the steam turbine via a main steam cutoff valve and a governor valve;
A condenser for condensing the main steam that has finished rotating the steam turbine;
A curtain spray device for spraying curtain spray water inside the condenser;
Temperature measuring means for measuring the temperature of the main steam introduction line;
A main steam bypass line branched from the upstream side of the governor valve of the main steam introduction line, bypassing the steam turbine and connected to the condenser;
A main steam bypass valve provided in the main steam bypass line;
A steam turbine plant operating method comprising:
When starting the steam turbine, with the main steam shut-off valve opened and the governor valve closed, the main steam bypass valve is opened, and the main steam introduction line to the governor valve is opened. The governor valve flows after the main steam flowing through the main steam introduction line flows from the main steam bypass line to the condenser until the temperature measured by the temperature measuring means is stabilized, and the temperature of the main steam introduction line is stabilized. Opening the valve to supply the main steam to the steam turbine and closing the main steam bypass valve ;
A method for operating a steam turbine plant, comprising: a step of opening the main steam shut-off valve and the main steam bypass valve after the curtain spray device is operated when the steam turbine is started . A boiler that produces main steam;
A steam turbine rotationally driven by the main steam;
A main steam introduction line for supplying the main steam generated in the boiler to the steam turbine via a main steam cutoff valve and a governor valve ;
A main steam water droplet detection unit that senses that there is a water droplet upstream of the main steam shutoff valve of the main steam introduction line;
A main steam drain valve for discharging the water droplets from the main steam introduction line;
A condenser for condensing the main steam that has finished rotating the steam turbine;
A curtain spray device for spraying curtain spray water inside the condenser;
A main steam bypass line branched from the upstream side of the governor valve of the main steam introduction line, bypassing the steam turbine and connected to the condenser;
A main steam bypass valve provided in the main steam bypass line;
A steam turbine plant operating method comprising:
If a water droplet detection signal is input from the main steam water droplet detection unit at the time of starting the steam turbine, the main steam drain valve is temporarily opened to discharge the water droplets, and then the main steam cutoff valve is opened. Supplying the main steam to the steam turbine ;
A method for operating a steam turbine plant, comprising: a step of opening the main steam shut-off valve and the main steam bypass valve after the curtain spray device is operated when the steam turbine is started . A boiler that produces main steam;
A steam turbine rotationally driven by the main steam;
A main steam introduction line for supplying the main steam generated in the boiler to the steam turbine via a main steam cutoff valve and a governor valve ;
A condenser for condensing the main steam that has finished rotating the steam turbine;
A curtain spray device for spraying curtain spray water inside the condenser;
A main steam bypass line branched from the upstream side of the governor valve of the main steam introduction line, bypassing the steam turbine and connected to the condenser;
A main steam bypass valve provided in the main steam bypass line;
An auxiliary steam introduction line for introducing auxiliary steam having a temperature lower than that of the main steam to the main steam introduction line via an auxiliary steam gate valve;
An auxiliary steam bypass line that branches off from the main steam introduction line and bypasses the steam turbine and leads to the condenser;
An auxiliary steam bypass valve provided in the auxiliary steam bypass line;
A steam turbine plant operating method comprising: an auxiliary steam water droplet sensing unit that senses that there are water droplets in the auxiliary steam introduction line;
When the auxiliary steam gate valve is opened and auxiliary steam is introduced from the auxiliary steam introduction line into the main steam introduction line, if there is a water drop detection signal from the auxiliary steam water drop sensing unit, the auxiliary steam bypass Opening the valve to flow the auxiliary steam flowing through the main steam introduction line from the auxiliary steam bypass line to the condenser until the water droplets disappear ,
A method for operating a steam turbine plant, comprising: a step of opening the main steam shut-off valve and the main steam bypass valve after the curtain spray device is operated when the steam turbine is started .

Images