JP5374317B2 - Steam turbine and method of operating steam turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steam turbine and a method for operating the same, which prevent steam leakage from a casing and improves performance of the turbine, even if the turbine is required to perform variable speed operation. <P>SOLUTION: This steam turbine includes: a cabin internally having a space for storing the turbine 2H and also having a divided surface; a regulation unit 5 regulating the steam flow rate supplied to the turbine 2H; and a control section 6 performing control to regulate the reduction rate of the steam flow rate with respect to the regulation section 5 so that, when the steam flow rate supplied to the turbine 2H is reduced, the contact pressure in an area adjacent to the space in the divided surface is set to predetermined contact pressure or more. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a steam turbine suitable for application to a steam turbine, in particular, a steam turbine requiring variable speed operation, and a method for operating the steam turbine.

In general, in a steam turbine, control for limiting the rotation speed of the steam turbine based on the wall temperature in the wall of the turbine casing when the rotation speed increases or when the output increases, particularly when the steam turbine starts up is known ( For example, see Patent Document 1.)
This is to prevent an excessive thermal stress from being applied to the turbine casing due to the temperature difference between the surface temperature of the wall of the turbine casing and the middle temperature of the wall.

On the other hand, when the rotational speed of the steam turbine is reduced or when the output is reduced, the operation state of the steam turbine, for example, control for limiting the rotational speed is not particularly performed.
In the case of a steam turbine used as a main engine of a ship, control (deceleration operation) is performed to reduce the output of the steam turbine when the ship is decelerated. Specifically, control for uniquely reducing the output of the steam turbine based on a command from the bridge is performed without monitoring the state of the steam turbine.

The steam turbine used as a marine main engine is different from a land-use steam turbine for business use at a rated speed in that a variable speed operation is always required as a propulsion engine.
In harbor navigation, steam turbines used as marine main engines are always required to be operated flexibly by increasing and decreasing speeds, and the frequency of speed reduction operations such as adjustment of operation schedules and when entering the port from open sea navigation is often used for land use. This is much more than a commercial steam turbine.

Japanese Patent No. 3480532

However, if the above-described deceleration operation is performed at a constant load change speed, there is a risk of steam leakage from the joint surface in the turbine casing.
In other words, as a result of dynamic characteristic simulation and unsteady FEM analysis in the passenger compartment of a steam turbine used as a marine main engine, the inner surface temperature of the passenger compartment is affected by changes in main steam temperature and reheat steam temperature flowing into the passenger compartment. Was found to be lower than the outer surface temperature. As a result, there is a problem that the possibility of causing a decrease in the surface pressure at the joint surface of the passenger compartment, which leads to steam leakage, is extremely high.

Furthermore, as a method for preventing or suppressing the above-described decrease in the surface pressure, a method for preventing a decrease in the surface pressure on the joint surface of the vehicle interior by changing the arrangement of the vehicle interior bolts, or a change in the wall thickness of the wall surface in the vehicle interior. For example, a method of preventing a decrease in surface pressure on the joint surface of the passenger compartment may be used.
However, only the method based on the bolt arrangement and the vehicle cabin structure has a limit, and a sufficient effect for preventing a reduction in surface pressure cannot be expected, and it is difficult to prevent or suppress steam leakage from the joint surface of the vehicle cabin. There was a problem.

  The present invention has been made to solve the above-described problems, and can prevent steam leakage from the passenger compartment and improve turbine performance even in a turbine that requires variable speed operation. It is an object of the present invention to provide a steam turbine and a method for operating the steam turbine.

In order to achieve the above object, the present invention provides the following means.
The steam turbine of the present invention has a space for housing the turbine therein, a compartment having a dividing surface, an adjusting unit for adjusting the steam flow rate supplied to the turbine, and the steam flow rate supplied to the turbine. In the case of decreasing, a control unit that controls the adjusting unit to adjust the rate of decrease in the steam flow rate so that the surface pressure of the region adjacent to the space on the dividing surface is equal to or greater than a predetermined surface pressure; Are provided.

  According to the present invention, when the flow rate of the steam supplied to the turbine is reduced, such as when the output of the turbine is reduced, the surface pressure in the region adjacent to the space in the split surface of the passenger compartment is a predetermined surface. When the pressure is smaller than the pressure, the rate of decrease in the steam flow rate is adjusted so that the surface pressure in the region adjacent to the space is equal to or greater than the predetermined surface pressure. For example, control for suppressing the rate of decrease in the steam flow rate is performed. Thereby, the fall of the surface pressure of the area | region adjacent to the said space is suppressed.

  Specifically, when the turbine is under steady operation, program automatic acceleration or program automatic deceleration, and the control to reduce the turbine output, the flow rate of steam supplied from the boiler to the turbine is reduced. Moreover, since the boiler load also decreases, the temperature of the supplied steam also decreases.

  When steam having a temperature lower than the wall surface temperature of the passenger compartment flows into the space in which the turbine is housed, the heat of the wall surface of the passenger compartment is taken away from the portion adjacent to the space and the temperature is lowered. At this time, a temperature difference is generated between the outside temperature of the vehicle interior wall surface and the temperature of the portion adjacent to the space. Further, there is a temperature difference between the temperature of the bolt that integrally holds the vehicle compartments divided by the dividing surface and the temperature of the portion adjacent to the space. That is, as compared with the outer portion and the bolt on the wall surface of the passenger compartment, the portion adjacent to the space on the passenger compartment wall surface is thermally contracted from an early stage, and the amount of thermal contraction is different. Thereby, the pressing force regarding the surface pressure in the area | region adjacent to the space in a division surface falls.

On the other hand, since the pressure of the steam supplied to the turbine gradually decreases, the steam pressure in the space also gradually decreases. That is, the force that pushes the split surface of the passenger compartment gradually decreases as compared with the decrease in the pressing force described above.
For these reasons, when the flow rate of steam supplied to the turbine is decreased, such as when the output of the turbine is decreased, the surface pressure in the region adjacent to the space decreases.

When the decrease in the surface pressure generated in this way becomes smaller than the predetermined surface pressure, the steam supplied to the turbine may leak to the outside through the bolt hole through which the above-described bolt is inserted from the divided surface.
Then, control which suppresses the decreasing rate of the steam flow rate adjusted by the adjustment part is performed.

As a result, the difference in the amount of heat shrinkage between the outer portion and the bolt on the wall surface of the passenger compartment and the portion adjacent to the space on the wall surface of the passenger compartment is reduced as compared to before the reduction rate of the steam flow rate is suppressed. Furthermore, the steam pressure supplied to the turbine is also reduced, and the force for expanding the dividing surface in the passenger compartment is also reduced.
For these reasons, compared to before the reduction rate of the steam flow rate is suppressed, the surface pressure in the region adjacent to the space on the dividing surface is increased, and the steam supplied to the turbine is less likely to leak to the outside.

  In the above invention, at least surface pressure information acquisition means for acquiring information on the surface pressure of the region adjacent to the space in the divided surface is provided, and the control unit is based on the acquired information on the surface pressure. It is desirable to control the rate of decrease in the steam flow rate so that the surface pressure of the region adjacent to the space on the dividing surface is equal to or higher than a predetermined surface pressure.

  According to the present invention, it is determined whether or not the surface pressure of the region adjacent to the space is actually smaller than the predetermined surface pressure based on the information on the surface pressure of the region adjacent to the space. Thereby, the control which suppresses the decreasing rate of the above-mentioned steam flow rate is performed appropriately, and the surface pressure fall of the area | region adjacent to the said space can be suppressed reliably.

  In the above invention, the surface pressure information acquisition means is a temperature measurement unit that measures the temperature of the region adjacent to the space on the divided surface and the outside temperature on the divided surface, and the control unit includes: Based on the temperature of the region adjacent to the space and the outside temperature, the reduction rate of the steam flow rate is controlled so that the surface pressure of the region adjacent to the space on the dividing surface is equal to or higher than a predetermined surface pressure. It is desirable.

  According to the present invention, the temperature of the region adjacent to the space on the dividing surface (the temperature of the inner portion of the vehicle interior wall surface) is compared with the temperature of the outside (the temperature of the outer portion of the vehicle interior wall surface). Whether or not the surface pressure of the region adjacent to the space is smaller than a predetermined surface pressure is determined based on whether or not the temperature of the region adjacent to the space is lower than the outside temperature.

Specifically, since the linear expansion coefficient of the material constituting the passenger compartment is known, the difference in shrinkage between these parts is determined based on the temperature difference between the temperature in the above region and the outside temperature. Can do. Further, the temperature of the bolt is estimated based on the temperature in the area adjacent to the space and the outside temperature, and based on the temperature difference between the temperature in the area and the temperature of the bolt, the difference in shrinkage between these parts. Can be requested.
Based on these, it is possible to determine the surface pressure of the region in consideration of the change in the pressing force related to the surface pressure of the region, and to determine whether the surface pressure of the region is smaller than a predetermined surface pressure.

  Compared with other methods of measuring the surface pressure in the region adjacent to the space, the temperature can be easily measured, so it is possible to easily determine whether or not to perform control for suppressing the rate of decrease in the steam flow rate. .

Alternatively, by acquiring in advance the relationship between the temperature in the region and the outside temperature and the surface pressure in the region, control is performed to hold down the decrease in the steam flow rate based on the temperature in the region and the outside temperature. It can also be judged directly.
Actually, it is necessary to consider the internal pressure in the operating state, but if the plant operating status can be predicted by dynamic characteristic simulation, it is possible to obtain information about the relationship between the temperature inside and outside the vehicle and the surface pressure in advance. And the above-mentioned determination can be made.

  In the above invention, the control unit performs the rate of decrease control of the steam flow rate for a predetermined period, and then a temperature obtained by adding a predetermined temperature to the temperature of the region adjacent to the space is less than the outside temperature. The steam flow rate reduction rate control is terminated, and when the temperature obtained by adding a predetermined temperature to the temperature of the region adjacent to the space is equal to or higher than the outside temperature, the steam flow rate reduction rate control is performed. It is desirable to continue.

  According to the present invention, after the first predetermined period has elapsed, the rate of decrease in the steam flow rate is determined based on whether the temperature obtained by adding the predetermined temperature to the temperature of the region adjacent to the space is less than the outside temperature. A determination is made as to whether to end the control to be adjusted or to perform control to adjust the rate of decrease in the steam flow rate only for a predetermined period.

  In determining whether or not to perform control to adjust the rate of decrease in the steam flow again, the determination is made based on whether or not the temperature obtained by adding a predetermined temperature to the temperature of the region adjacent to the space is less than the outside temperature. The reason is as follows.

  In other words, compared with the time when it was first determined whether or not to perform the control to adjust the rate of decrease in the steam flow rate, the time elapsed since the start of the decrease in the turbine output was long. The temperature of the bolt to be integrated is lowered by heat transfer. Then, since the bolt is thermally contracted and the tightening force is restored, even if the temperature of the region adjacent to the space is lower than the outside temperature, if the temperature difference is less than a predetermined temperature, This is because the surface pressure of the region adjacent to the space can be maintained at a predetermined surface pressure or higher.

  Furthermore, since the pressure of the steam supplied to the turbine is lower than when the control for adjusting the rate of decrease in the steam flow rate is first performed, the dividing surface in the passenger compartment is reduced. The force to spread out has decreased. Therefore, even if the temperature of the region adjacent to the space is lower than the outside temperature, the surface pressure of the region adjacent to the space is maintained at a predetermined surface pressure or more if the temperature difference is less than the predetermined temperature. Because it can.

  The predetermined temperature described above may be a fixed value, or may be a value that changes based on the pressure of the steam supplied to the turbine or the pressure inside the space, and is not particularly limited.

  In the above invention, it is desirable that the control unit performs control to adjust the rate of decrease in the steam flow rate by holding the decrease in the steam flow rate to the adjusting unit.

  According to the present invention, the control for adjusting the rate of decrease in the steam flow rate is performed by holding down the decrease in the steam flow rate. In other words, the steam flow rate and the steam temperature supplied to the turbine are roughly fixed to the steam flow rate and the steam temperature when it is determined that the surface pressure in the region adjacent to the space is less than the predetermined surface pressure.

  Then, the temperature of the steam supplied to the turbine is kept approximately constant, and the amount of heat shrinkage between the outer portion and the bolt on the wall surface of the above-described casing and the amount of heat shrinkage of the portion adjacent to the space on the wall surface of the passenger compartment. The heat shrinkage difference is reduced. This is a case where, for example, the rate of decrease in the steam flow rate is suppressed, and when the temperature of the steam supplied to the turbine is gradually reduced, the time is shorter than the time when the difference in the amount of heat shrinkage is reduced. The heat shrinkage difference is reduced.

  The steam turbine operating method according to the present invention obtains information on the flow rate reduction step for reducing the flow rate of steam supplied to the turbine and the surface pressure of the dividing surface in the passenger compartment in which the turbine is housed based on an instruction from the outside. A comparison step for comparing whether or not the surface pressure estimated based on the acquired surface pressure information is smaller than a predetermined surface pressure; and when the estimated surface pressure is smaller than the predetermined surface pressure Comprises a reduction rate adjusting step for adjusting the reduction rate of the steam flow rate.

  According to the present invention, when the flow rate of the steam supplied to the turbine is reduced, such as when the output of the turbine is reduced, the surface pressure in the region adjacent to the space in the split surface of the passenger compartment is the predetermined surface. When the pressure is smaller than the pressure, the rate of decrease in the steam flow rate is adjusted so that the surface pressure in the region adjacent to the space becomes equal to or higher than the predetermined surface pressure. For example, control for suppressing the rate of decrease in the steam flow rate is performed. Thereby, the fall of the surface pressure of the area | region adjacent to the said space is suppressed.

  According to the steam turbine and the operation method of the steam turbine of the present invention, when the flow rate of steam supplied to the turbine is decreased, the steam pressure is increased so that the surface pressure in the region adjacent to the space on the dividing surface is equal to or higher than the predetermined surface pressure. Since the rate of reduction of the flow rate is adjusted, even a turbine that requires variable speed operation has the effect of preventing steam leakage from the passenger compartment and improving the turbine performance.

It is a mimetic diagram explaining the schematic structure of the steam turbine concerning one embodiment of the present invention. It is a schematic diagram explaining the structure of the compartment which accommodates the high pressure turbine and intermediate pressure turbine of FIG. FIG. 3 is a cross-sectional view taken along the line A-A for explaining arrangement positions of a high-pressure inner temperature measurement unit and a high-pressure outer temperature measurement unit in the passenger compartment of FIG. 2. FIG. 3 is a cross-sectional view taken along the line B-B for explaining arrangement positions of an intermediate pressure inner temperature measurement unit and an intermediate pressure outer temperature measurement unit in the passenger compartment of FIG. 2. It is a block diagram explaining the structure of the control part of FIG. It is a graph explaining the change of the output fluctuation of the steam turbine, the temperature of the main steam, and the temperature of the reheat steam when the conventional deceleration control is performed. It is a schematic diagram explaining the place which calculated the temperature change in the inlet_port | entrance vicinity of the high pressure turbine and intermediate pressure turbine in a vehicle interior. It is a graph explaining the temperature change of the compartment in the entrance vicinity of the conventional high pressure turbine. It is a graph explaining the temperature change of the compartment in the entrance vicinity of the conventional intermediate pressure turbine. It is a flowchart explaining the deceleration control in this embodiment. It is a graph explaining the temperature change of the inner wall surface and outer wall surface of a compartment in the vicinity of the inlet of the high pressure turbine in this embodiment. It is a graph explaining the change of the temperature difference of the inner wall surface in the vicinity of the inlet_port | entrance of the high pressure turbine in the prior art and this embodiment, and an outer wall surface. It is a graph explaining the temperature change of the inner wall surface and outer wall surface of a compartment in the vicinity of the entrance of the intermediate pressure turbine in this embodiment. It is a graph explaining the change of the temperature difference of the inner wall surface in the vicinity of the inlet_port | entrance of the intermediate pressure turbine in the prior art and this embodiment, and an outer wall surface.

A steam turbine according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic diagram illustrating a schematic configuration of a steam turbine according to the present embodiment. FIG. 2 is a schematic diagram illustrating a configuration of a vehicle compartment that houses the high-pressure turbine and the intermediate-pressure turbine of FIG.
The steam turbine 1 according to the present embodiment is used as a main engine of a ship, and is a reheat turbine including a reheater 4R that heats steam discharged from a high-pressure turbine 2H.

  As shown in FIGS. 1 and 2, the steam turbine 1 includes a casing 3 that houses a steam high-pressure turbine (turbine) 2H and an intermediate-pressure turbine 2M, and a main boiler (boiler) that supplies main steam to the high-pressure turbine 2H. 4H, a reheater 4R for supplying reheated steam to the intermediate pressure turbine 2M, a governor 5 for adjusting the flow rate of the main steam, a control unit 6 for remotely controlling the steam turbine 1, and a main boiler ( (Boiler) 4H and the control part 7 which controls the reheater 4R are mainly provided.

FIG. 3 is a cross-sectional view taken along the line A-A for explaining the arrangement positions of the high-pressure inner temperature measurement unit and the high-pressure outer temperature measurement unit in the passenger compartment of FIG. 4 is a cross-sectional view taken along the line B-B for explaining the arrangement positions of the intermediate pressure inner temperature measurement unit and the intermediate pressure outer temperature measurement unit in the passenger compartment of FIG. 2.
The vehicle interior 3 houses the high-pressure turbine 2H and the intermediate-pressure turbine 2M and introduces steam.
As shown in FIGS. 2 to 4, the vehicle interior 3 includes a space S that accommodates the high-pressure turbine 2 </ b> H and the intermediate-pressure turbine 2 </ b> M, a split surface SP that divides the vehicle interior 3 into two parts, and a high-pressure side inlet. Inner wall temperature sensor (surface pressure information acquisition means, temperature measurement section) 31H, high pressure side inlet outer wall temperature sensor (surface pressure information acquisition means, temperature measurement section) 32H, intermediate pressure side inlet inner wall temperature sensor 31M, and intermediate pressure side inlet outer wall A temperature sensor 32M is mainly provided.

  The high-pressure turbine 2H and the intermediate-pressure turbine 2M are arranged at equal intervals in the circumferential direction of the rotating shaft (not shown), and the turbine rotor blades arranged at intervals in the axial direction of the rotating shaft, and the casing 3 It is mainly comprised from the turbine stationary blade provided in.

As shown in FIG. 1, the high-pressure turbine 2H receives the supply of main steam from the main boiler 4H and generates a rotational driving force.
The intermediate pressure turbine 2M receives a supply of reheated steam from the reheater 4R and generates a rotational driving force.

  As shown in FIGS. 2 to 4, the space S is a space formed inside the passenger compartment 3, in which the high-pressure turbine 2 </ b> H and the intermediate-pressure turbine 2 </ b> M are disposed, and main steam and reheat steam flow. A flow path is formed.

As shown in FIGS. 3 and 4, the dividing surface SP is a surface that divides the vehicle compartment 3 into two parts, an upper vehicle compartment 3U and a lower vehicle compartment 3L. In other words, it is a surface where the upper casing 3U and the lower casing 3L come into contact.
The upper casing 3U and the lower casing 3L are integrally tightened by bolts 42 inserted through bolt holes 41 provided in the upper casing 3U. Further, the lower passenger compartment 3L is provided with a high pressure side inlet inner wall temperature sensor 31H, a high pressure side inlet outer wall temperature sensor 32H, an intermediate pressure side inlet inner wall temperature sensor 31M, and an intermediate pressure side inlet outer wall temperature sensor 32M.

  The high pressure side inlet inner wall temperature sensor 31H and the high pressure side inlet outer wall temperature sensor 32H measure the temperature in the vicinity of the region where the main steam flows into the high pressure turbine 2H in the lower casing 3L, as shown in FIGS. .

The high pressure side inlet inner wall temperature sensor 31H is a region where the main steam flows into the high pressure turbine 2H, and includes a casing in a cross section including a point where the distance between the inner wall surface of the casing 3 and the bolt hole 41 is the farthest. 3 is used to measure the temperature of the inner wall surface 3 (the temperature of the region adjacent to the space). In other words, the temperature of the inner wall surface of the region where the surface pressure at the dividing surface SP first decreases is measured.
Furthermore, the high pressure side inlet inner wall temperature sensor 31H outputs a measurement signal related to the temperature of the inner wall surface to the control unit 6.

  The high pressure side inlet outer wall temperature sensor 32H is a region where the main steam flows into the high pressure turbine 2H, and includes a casing in a cross section including a point where the distance between the inner wall surface of the casing 3 and the bolt hole 41 is the farthest. The temperature of the outer wall surface 3 is measured. Further, the high pressure side inlet outer wall temperature sensor 32H outputs a measurement signal related to the temperature of the outer wall surface (outside temperature) to the control unit 6.

  The medium pressure side inlet inner wall temperature sensor 31M and the medium pressure side inlet outer wall temperature sensor 32M measure the temperature in the vicinity of the region where the reheated steam in the lower casing 3L flows into the intermediate pressure turbine 2M as shown in FIGS. It is.

The intermediate pressure side inner wall temperature sensor 31M is a region where reheated steam flows into the intermediate pressure turbine 2M, and includes a cross section including a point where the distance between the inner wall surface of the casing 3 and the bolt hole 41 is farthest. The temperature of the inner wall surface of the passenger compartment 3 is measured. In other words, the temperature of the inner wall surface of the region where the surface pressure at the dividing surface SP first decreases is measured.
Further, the intermediate pressure side inner wall temperature sensor 31M outputs a measurement signal related to the temperature of the inner wall surface to the control unit 6.

  The intermediate pressure side inlet outer wall temperature sensor 32M is a region where reheated steam flows into the intermediate pressure turbine 2M, and includes a cross section including a point where the distance between the inner wall surface of the casing 3 and the bolt hole 41 is farthest. The temperature of the outer wall surface of the passenger compartment 3 is measured. Further, the intermediate pressure side outer wall temperature sensor 32M outputs a measurement signal related to the temperature of the outer wall surface to the control unit 6.

  Further, a high pressure side outlet inner wall temperature sensor 33H, a high pressure side outlet outer wall temperature sensor 34H, a medium pressure side outlet inner wall temperature sensor 33M, and a medium pressure side outlet outer wall temperature sensor 34M are provided in the vehicle compartment 3 so that the temperature of the vehicle compartment 3 is increased. May be measured and used for control in the control unit 6.

  The control in the control unit 6 is mainly performed based on measurement signals from the high pressure side inlet inner wall temperature sensor 31H, the high pressure side inlet outer wall temperature sensor 32H, the intermediate pressure side inlet inner wall temperature sensor 31M, and the intermediate pressure side inlet outer wall temperature sensor 32M. The measurement signals of the high pressure side outlet inner wall temperature sensor 33H, the high pressure side outlet outer wall temperature sensor 34H, the intermediate pressure side outlet inner wall temperature sensor 33M and the intermediate pressure side outlet outer wall temperature sensor 34M are used as reference information.

  The high-pressure side outlet inner wall temperature sensor 33H and the high-pressure side outlet outer wall temperature sensor 34H measure the temperature in the vicinity of the region where the main steam flows out from the high-pressure turbine 2H in the lower casing 3L, as shown in FIG.

  The high pressure side outlet inner wall temperature sensor 33H measures the temperature of the inner wall surface of the passenger compartment 3 in the cross section of the region where the main steam flows out from the high pressure turbine 2H. Furthermore, the high-pressure side outlet inner wall temperature sensor 33H outputs a measurement signal related to the temperature of the inner wall surface to the control unit 6.

  The high pressure side outlet outer wall temperature sensor 34H measures the temperature of the outer wall surface of the passenger compartment 3 in the cross section of the region where the main steam flows out from the high pressure turbine 2H. Furthermore, the high-pressure side outlet outer wall temperature sensor 34H outputs a measurement signal related to the temperature of the outer wall surface to the control unit 6.

  The intermediate pressure side outlet inner wall temperature sensor 33M and the intermediate pressure side outlet outer wall temperature sensor 34M measure the temperature in the vicinity of the region where the reheated steam in the lower casing 3L flows out of the intermediate pressure turbine 2M, as shown in FIG.

  The medium pressure side outlet inner wall temperature sensor 33M measures the temperature of the inner wall surface of the passenger compartment 3 in the cross section of the region where the reheat steam flows out from the medium pressure turbine 2M. Further, the intermediate pressure side outlet inner wall temperature sensor 33M outputs a measurement signal related to the temperature of the inner wall surface to the control unit 6.

  The medium pressure side outlet outer wall temperature sensor 34M measures the temperature of the outer wall surface of the passenger compartment 3 in the cross section of the region where the reheat steam flows out from the intermediate pressure turbine 2M. Further, the intermediate pressure side outer wall temperature sensor 34M outputs a measurement signal related to the temperature of the outer wall surface to the control unit 6.

In addition, a high pressure side inlet bolt temperature sensor 35H, a medium pressure side inlet bolt temperature sensor 35M, a high pressure side outlet bolt temperature sensor 36H, and a medium pressure side outlet bolt temperature sensor 36M are provided to measure the temperature of the bolt 42. Thus, it may be used as a reference temperature for control in the control unit 6.
The measurement signals of the high pressure side inlet bolt temperature sensor 35H, the intermediate pressure side inlet bolt temperature sensor 35M, the high pressure side outlet bolt temperature sensor 36H and the intermediate pressure side outlet bolt temperature sensor 36M indicate that the temperature of the corresponding bolt 42 is It is used for checking whether or not it changes in conjunction with the inner wall temperature or the outer wall temperature.

As shown in FIG. 2, the high-pressure side inlet bolt temperature sensor 35H measures the temperature of the bolt 42 disposed in the vicinity of the region where the main steam flows into the high-pressure turbine 2H. Further, the high-pressure side inlet bolt temperature sensor 35H outputs a measurement signal related to the temperature of the bolt 42 to the control unit 6.
The intermediate pressure side inlet bolt temperature sensor 35M measures the temperature in the vicinity of the region where the reheated steam flows into the intermediate pressure turbine 2M. Further, the intermediate pressure side inlet bolt temperature sensor 35M outputs a measurement signal related to the temperature of the bolt 42 to the control unit 6.

The high-pressure side outlet bolt temperature sensor 36H measures the temperature of the bolt 42 disposed in the vicinity of the region where the main steam flows out from the high-pressure turbine 2H. Furthermore, the high-pressure side outlet bolt temperature sensor 36 </ b> H outputs a measurement signal related to the temperature of the bolt 42 described above to the control unit 6.
The intermediate pressure side outlet bolt temperature sensor 36M measures the temperature in the vicinity of the region where the reheat steam flows out from the intermediate pressure turbine 2M. Further, the intermediate pressure side outlet bolt temperature sensor 36M outputs a measurement signal related to the temperature of the bolt 42 described above to the control unit 6.

As shown in FIG. 1, the main boiler 4H generates steam using heat obtained by burning fuel supplied from the outside, and supplies main steam to the high-pressure turbine 2H.
As shown in FIG. 1, the reheater 4R reheats the steam discharged from the high pressure turbine 2H using heat obtained by burning the fuel, and supplies the reheat steam to the intermediate pressure turbine 2M. is there.

The supply of the main steam and the reheat steam by the main boiler 4H and the reheater 4R is controlled by the control unit 7 from the steam state and the governor opening instruction value by the governor 5 controlled by the control unit 6.
In addition, as a main boiler 4H and the reheater 4R, a well-known thing can be used and it does not specifically limit.

As shown in FIG. 1, the governor 5 controls the flow rate of main steam supplied from the main boiler 4 </ b> H to the high-pressure turbine 2 </ b> H according to the load of the steam turbine 1. In other words, the flow rate of the main steam is controlled so that the output of the steam turbine 1 becomes the output instructed by the control unit 6.
In addition, as a governor 5, a well-known thing can be used and it does not specifically limit.

FIG. 5 is a block diagram illustrating the configuration of the control unit in FIG.
The control unit 6 controls the governor 5 and the like, and controls the main boiler 4H and the reheater 4R based on a command from the ship's bridge and a measurement signal from the high-pressure inlet inner wall temperature sensor 31H. A governor opening instruction value is transmitted.
As shown in FIG. 5, the control unit 6 includes commands from the bridge, a high pressure side inlet inner wall temperature sensor 31H, a high pressure side inlet outer wall temperature sensor 32H, a medium pressure side inlet inner wall temperature sensor 31M, and a medium pressure side inlet outer wall temperature sensor 32M. The measurement signal is mainly input.

Furthermore, the control unit 6 may receive measurement signals from the high pressure side outlet inner wall temperature sensor 33H, the high pressure side outlet outer wall temperature sensor 34H, the intermediate pressure side outlet inner wall temperature sensor 33M, and the intermediate pressure side outlet outer wall temperature sensor 34M.
In addition, measurement signals from the high pressure side inlet bolt temperature sensor 35H, the intermediate pressure side inlet bolt temperature sensor 35M, the high pressure side outlet bolt temperature sensor 36H, and the intermediate pressure side outlet bolt temperature sensor 36M may be input to the control unit 6.

The control unit 6 outputs a control signal for controlling the flow rate of the main steam to the governor 5, and the control unit 7 outputs a control signal for controlling the flow rate of the fuel supplied to the main boiler 4H and the reheater 4R. Yes.
Details of the control method by the control unit 6 will be described later.

  The control unit 7 controls the main boiler 4H and the reheater 4R based on the governor lift instruction value and the operation mode information input from the control unit 6 and the state of the main steam and the reheat steam.

  Next, a description will be given of a control method in the steam turbine 1 having the above-described configuration, particularly deceleration control from a state where the load of the steam turbine 1 is high, such as when switching from the ocean navigation mode to the port navigation mode.

  Here, the harbor navigation mode is a mode mainly used when a ship navigates in the harbor, and is a load in the range of about 0% to about 25% with respect to the maximum load of the steam turbine 1 as the main engine. The mode used. On the other hand, the ocean navigation mode is a mode used when a ship navigates the ocean, and is a mode used in a state where the load of the steam turbine 1 is higher than that in the harbor navigation mode.

First, the flow of steam in the steam turbine 1 will be described with reference to FIG.
The steam is generated using heat obtained by fuel combustion in the main boiler 4H, and is supplied to the high-pressure turbine 2H in the passenger compartment 3 as high-temperature and high-pressure main steam. At this time, the flow rate of the fuel supplied to the main boiler 4H is controlled by the control unit 7. Further, the flow rate of the main steam supplied from the main boiler 4H to the high pressure turbine 2H is controlled by the governor 5 to which a control signal (command) is input from the control unit 6.

  The main steam is driven to rotate the high-pressure turbine 2 </ b> H, so that the pressure and temperature are reduced, and the main steam is discharged out of the passenger compartment 3. The discharged main steam is heated by using heat obtained by fuel combustion in the reheater 4R, and is supplied to the intermediate pressure turbine 2M in the passenger compartment 3 as high-temperature reheat steam. At this time, the flow rate of the fuel supplied to the reheater 4R is controlled by the control unit 7.

The reheated steam is driven to rotate the intermediate pressure turbine 2M, so that the pressure and temperature thereof are reduced and discharged to the outside of the passenger compartment 3.
At this time, the passenger compartment 3 is warmed by the main steam and reheat steam supplied to the interior.

  The above description is applied to the case of the ocean navigation mode (Normal Mode) in which fuel is burned in the reheater 4R. In the harbor navigation mode (Harbor Mode), the fuel is not burned in the reheater 4R, which is different from the ocean navigation mode.

Next, deceleration control from a state where the load of the steam turbine 1 is high, which is a feature of the present embodiment, will be described. Here, description will be made by applying to a case where the ocean navigation mode is switched to the port navigation mode (for example, equivalent to the port navigation ship speed FULL) in a short time (for example, 10 minutes, 30 minutes, 45 minutes, etc.).
First, the conventional deceleration control and its problems will be described, and then the deceleration control of this embodiment and its effects will be described.

In the case of conventional deceleration control, the turbine remote controller creates a time schedule for controlling the time change of the governor lift (governer opening) based on the target value of the output of the steam turbine and the time required for control. This is done by controlling the governor lift according to a schedule. Furthermore, the flow rate of the fuel supplied to the main boiler and the reheater is also controlled according to the output of the steam turbine.
In other words, the governor lift is not controlled in consideration of the casing temperature of the steam turbine.

FIG. 6 is a graph for explaining changes in output of the steam turbine, main steam temperature, and reheat steam temperature when conventional deceleration control is performed.
Here, a simulation result when the output of the steam turbine 1 is reduced to about 1/5 in about 15 minutes will be described. The horizontal axis in FIG. 6 shows the elapsed time from the start of the deceleration control in minutes, and the vertical axis shows the output of the steam turbine 1, the temperature of the main steam, and the temperature of the reheat steam. . Further, the output of the steam turbine 1 is a graph with a symbol P, the temperature of the main steam is a graph with a symbol TH, and the temperature of the reheated steam is a graph with a symbol TR.

  As shown in FIG. 6, the output P of the steam turbine 1, the temperature TH of the main steam, and the temperature TR of the reheated steam remain constant until about 3 minutes have passed since the deceleration control was started. At this time, the temperature TM of the main steam and the temperature TR of the reheated steam are substantially the same.

  Thereafter, the output P of the steam turbine 1 starts decreasing, and the output continues to decrease at a constant rate until about 7 minutes elapse from the start of the deceleration control. Then, the reduction rate of the output P of the steam turbine 1 is reduced from about 7 minutes to about 10 minutes, and the reduction rate is increased again after about 10 minutes. The output P of the steam turbine 1 temporarily becomes smaller than about one fifth of the pre-control output, which is the target value (undershoot), then gradually approaches the target value, and reaches the target value about 15 minutes after the start of control. Controlled.

On the other hand, when about 5 minutes have elapsed from the start of the deceleration control with a delay in the decrease in the output P of the steam turbine 1, the decrease in the temperature TH of the main steam and the temperature TR of the reheat steam begins.
Compared to the temperature TR of the reheated steam, the temperature TH of the main steam is lowered in advance, and the reversal of the temperature TH of the main steam and the temperature TR of the reheated steam occurs. This reverse rotation reaches about 50 ° C. at the maximum, and continues after the output P of the steam turbine 1 has decreased to about 1/5, which is the target value, and is maintained until about 30 minutes have elapsed from the start of the deceleration control.

  That is, since the main steam is heated by the reheater 4R after the high-pressure turbine is driven to rotate, the reheat steam temperature TR is more followable than the main steam temperature TH. Such a phenomenon occurs because of the poor. Specifically, the temperature TH of the main steam begins to decrease at an early stage as compared with the temperature TR of the reheated steam, and the temperature starts to become constant about 25 minutes after the start of control. On the other hand, the temperature TR of the reheated steam begins to decrease with a delay from the temperature TH of the main steam, and the temperature decreases to the temperature TH of the main steam in about 30 minutes from the start of the control.

Next, the simulation result of the temperature change of the passenger compartment when the conventional deceleration control is performed will be described.
FIG. 7 is a schematic diagram for explaining a place where the temperature change in the vicinity of the inlet of the high-pressure turbine and the intermediate-pressure turbine in the passenger compartment is calculated.
A point HI in FIG. 7 is a point where the temperature change on the inner wall surface in the passenger compartment 3 near the inlet of the high pressure turbine 2H is observed, and a point HO is a point where the temperature change on the outer wall surface is observed. Further, the point MI is a point where the temperature change on the inner wall surface near the entrance of the intermediate pressure turbine 2M in the passenger compartment 3 is observed, and the point MO is a point where the temperature change on the outer wall surface is observed.

FIG. 8 is a graph for explaining the temperature change of the passenger compartment in the vicinity of the inlet of the conventional high-pressure turbine.
First, based on FIG. 8, the temperature change of the point HI on the inner wall surface of the casing 3 and the point HO on the outer wall surface in the vicinity of the inlet of the high-pressure turbine 2H will be described.
In the vicinity of an elapsed time of 0 minutes when deceleration control is started, the temperature at the point HI is kept higher than the temperature at the point HO. The reason why the point HI is relatively high is that, as shown in FIG. 6, high-temperature main steam is supplied to the space S in which the high-pressure turbine 2H facing the point HI is disposed.

  When the deceleration control is started, the flow rate of the main steam supplied to the high-pressure turbine 2H decreases and the temperature of the main steam also decreases. Therefore, the amount of heat supplied to the inner wall surface (including the point HI) of the passenger compartment 3 is reduced. Decrease. As a result, the temperature at the point HI decreases with time and stabilizes in about 30 minutes from the start of the control in which the temperature change of the main steam is stabilized.

On the other hand, the temperature of the outer wall surface (including the point HO) of the passenger compartment 3 is not directly affected by the temperature drop of the main steam but depends on the amount of heat transmitted from the inner side to the outer side of the inner wall surface of the passenger compartment 3. For this reason, the temperature gradually falls below the temperature at the point HI.
As a result, it can be seen from FIG. 8 that the reversal of the temperature at the point HI and the temperature at the point HO occurs about 5 minutes after the start of the deceleration control.

FIG. 9 is a graph for explaining the temperature change of the passenger compartment in the vicinity of the inlet of the intermediate pressure turbine.
Next, based on FIG. 9, the temperature change of the point MI on the inner wall surface of the casing 3 and the point MO on the outer wall surface in the vicinity of the inlet of the intermediate pressure turbine 2M will be described.
The intermediate pressure turbine 2M is supplied with reheat steam having a lower temperature followability with respect to the deceleration control than the main steam as shown in FIG. 6, so that the temperature change at the point MI is the temperature change at the point HI. Compared to Specifically, the temperature decrease at the point MI starts after about 10 minutes have elapsed from the start of the deceleration control, and the temperature decrease rate increases after about 15 minutes have elapsed.

On the other hand, the temperature at the point MO is not affected by the temperature drop of the reheated steam directly like the temperature at the point HO, and depends on the amount of heat transmitted from the inner side to the outer side of the wall surface of the passenger compartment 3, It drops more slowly than the temperature at the point HI.
As a result, it can be seen from FIG. 9 that the temperature at the point MI and the temperature at the point MO are reversed approximately 23 minutes after the start of the deceleration control.

  As described above, when the reversal of the temperature at the point HI and the temperature at the point HO and the reversal of the temperature at the point MI and the temperature at the point MO occur, the amount of heat shrinkage on the inner wall surface of the passenger compartment 3 is reduced on the outer wall surface. The amount of heat shrinkage becomes larger, and the surface pressure in the vicinity of the inner wall surface at the dividing surface SP decreases.

  Further, since the temperature at the bolt 42 arranged between the inner wall surface and the outer wall surface is higher than the temperature at the inner wall surface immediately after the deceleration operation is started, the amount of heat shrinkage at the bolt 42 is the amount of heat shrinkage at the inner wall surface. Not big compared to. That is, since the tightening force for tightening the upper casing 3U and the lower casing 3L with the bolts 42 is reduced, the surface pressure at the dividing surface SP is further reduced.

Next, the deceleration control in this embodiment will be described.
FIG. 10 is a flowchart for explaining the deceleration control in the present embodiment.
First, an instruction to reduce the navigation speed of the ship is input from the bridge to the control unit 6. For example, an instruction to switch (decelerate) from the ocean navigation mode to the port navigation mode in order to enter the ship is input (control order step S1). At the same time, the time required to decelerate the ship to the instructed navigation speed is also input.

  Based on the input instruction, the control unit 6 calculates the main steam flow rate in the governor 5 corresponding to the instructed navigation speed, that is, the lift amount of the governor 5 (hereinafter referred to as “order lift amount”). . Further, a time schedule for changing the current lift amount of the governor 5 to the order lift amount within the input required time is calculated. Thereafter, the control unit 6 controls the lift amount of the governor 5 according to the calculated time schedule (a governor control step (flow rate reduction step) S2).

When the lift amount control of the governor 5 is started, the lift amount of the governor 5 gradually decreases, so that the flow rate of the main steam passing through the governor 5 decreases. As a result, the flow rate of the main steam supplied to the high pressure turbine 2H and the flow rate of the reheat steam supplied to the intermediate pressure turbine 2M are reduced.
At the same time, the control unit 7 performs control to reduce the flow rate of the fuel supplied to the main boiler 4H and the reheater 4R according to the instruction value of the control unit 6, the main steam and the reheat steam state. Therefore, the main steam temperature supplied from the main boiler 4H and the reheat steam temperature supplied from the reheater 4R are lowered.

  When the lift amount control of the governor 5 is started, the control unit 6 performs a high pressure side inlet / outlet inner wall temperature sensor 31H / 33H, a high pressure side inlet / outlet outer wall temperature sensor 32H / 34H, and a medium pressure side inlet / outlet inner wall temperature sensor 31M / Based on the measurement signals of 33M and the intermediate pressure side inlet / outlet outer wall temperature sensor 32M / 34M, the inside of the vehicle compartment 3 in the vicinity of the main steam inlet and outlet of the high pressure turbine 2H and the reheat steam inlet and outlet of the intermediate pressure turbine 2M The wall surface temperature is compared with the outer wall surface temperature (first temperature comparison step (comparison step) S3).

When the inner wall surface temperature is equal to or higher than the outer wall surface temperature, the control unit 6 compares the lift amount of the governor 5 at that time with the order lift amount (first lift comparison step S4).
If the lift amount of the governor 5 at that time is not equal to the order lift amount, the process returns to the governor control step S2 and the control of the lift amount of the governor 5 according to the time schedule is continued.
On the other hand, when the lift amount of the governor 5 at that time is equal to the order lift amount, the deceleration control by the control unit 6 ends.

When the inner wall surface temperature is lower than the outer wall surface temperature, the control unit 6 performs control to hold the lift amount of the governor 5 at the lift amount at that time (lift amount holding step (decrease rate adjusting step) S5).
The holding of the lift amount is continued for a predetermined period, for example, about 10 minutes.

By maintaining the lift amount, a decrease in the steam flow rate is suspended and a decrease in the steam temperature is also suspended. For example, when the rate of decrease in the steam flow rate is suppressed, the steam temperature supplied to the high-pressure turbine 2H gradually decreases, whereas when the decrease in the steam flow rate is suppressed, the steam temperature is kept constant. It is.
Therefore, the heat shrinkage difference between the heat shrinkage amount of the outer portion and the bolt 42 on the wall surface of the vehicle interior 3 and the heat shrinkage amount of the portion (inner portion) adjacent to the space S on the wall surface of the vehicle cabin 3 is calculated. It can be reduced in a shorter time.

  When the period for holding the lift amount elapses, the control unit 6 again returns to the high pressure side inlet / outlet inner wall temperature sensor 31H / 33H, the high pressure side inlet / outlet outer wall temperature sensor 32H / 34H, and the intermediate pressure side inlet / outlet inner wall temperature sensor 31M / Based on the measurement signals of 33M and the intermediate pressure side inlet / outlet outer wall temperature sensor 32M / 34M, the main wall inlet and outlet of the high pressure turbine 2H and the inner wall of the vehicle compartment 3 in the vicinity of the reheat steam inlet and outlet of the intermediate pressure turbine 2M The temperature obtained by adding the first predetermined temperature (predetermined temperature) α1 to the temperature is compared with the outer wall surface temperature (second temperature comparison step S6).

An example of the first predetermined temperature α1 is about 50 ° C.
When the second temperature comparison step S6 is performed, the determination is made based on whether or not the temperature obtained by adding the first predetermined temperature α1 to the inner wall temperature of the passenger compartment 3 is lower than the outer wall surface temperature for the following reason.

  That is, since the time elapsed since the output reduction of the steam turbine 1 is started is longer than when the first temperature comparison step S3 is performed, the temperature of the bolt 42 for tightening and integrating the casing 3 is transmitted. It is lowered by heat. Then, since the bolt 42 is thermally contracted and the tightening force is restored, even if the inner wall temperature is lower than the outer wall temperature, if the temperature difference is less than the first predetermined temperature α1, it is adjacent to the space S. This is because the surface pressure in the region can be maintained at a predetermined surface pressure or more.

  Furthermore, compared to when the first temperature comparison step S3 is performed, the flow rate of steam supplied to the high-pressure turbine 2H is reduced, and the pressure inside the turbine is low. The power to spread is decreasing. Therefore, even if the inner wall temperature is lower than the temperature of the outer wall surface temperature, if the temperature difference is less than the first predetermined temperature α1, the surface pressure in the region adjacent to the space S can be kept equal to or higher than the predetermined surface pressure. Because it can.

  The first predetermined temperature α1 may be a fixed temperature, or may be a temperature that changes based on the pressure of the steam supplied to the high-pressure turbine 2H or the pressure inside the space S, and is particularly limited. Not what you want.

  When the temperature obtained by adding the first predetermined temperature (α1) to the inner wall temperature is lower than the outer wall temperature, the control unit 6 returns to the lift amount holding step S5 again and the holding of the lift amount is repeated for a predetermined period.

  On the other hand, when the temperature obtained by adding the first predetermined temperature (α1) to the inner wall temperature is equal to or higher than the outer wall temperature, the control unit 6 resumes the lift amount control of the governor 5 according to the time schedule (governor control resume step S7). ).

  When the lift amount control of the governor 5 is resumed, the control unit 6 further includes a high pressure side inlet / outlet inner wall temperature sensor 31H / 33H, a high pressure side inlet / outlet outer wall temperature sensor 32H / 34H, and a medium pressure side inlet / outlet inner wall temperature sensor. Based on the measurement signals of 31M / 33M and the intermediate pressure side inlet / outlet outer wall temperature sensor 32M / 34M, the casing 3 in the vicinity of the main steam inlet and outlet of the high pressure turbine 2H and the reheat steam inlet and outlet of the intermediate pressure turbine 2M The temperature obtained by adding the second predetermined temperature (predetermined temperature) α2 to the inner wall temperature is compared with the outer wall surface temperature (third temperature comparison step S8).

  The second predetermined temperature α2 may be about 50 ° C., which is the same as the first predetermined temperature α1, or may be a temperature higher than the first predetermined temperature α1, and is not particularly limited.

  That is, when the third temperature comparison step S8 in which the second predetermined temperature α2 is used is performed, the high pressure turbine 2H is compared with the case in which the second temperature comparison step S6 in which the first predetermined temperature α1 is used is performed. As the flow rate of the main steam supplied decreases, the pressure inside the turbine and the pressure of the reheat steam supplied to the intermediate pressure turbine 2M decrease. Therefore, when the third temperature comparison step S8 is performed compared to when the second temperature comparison step S6 is performed, the force that pushes the dividing surface SP of the passenger compartment 3 is weakened. Even if α2 is a temperature higher than the first predetermined temperature α1, the surface pressure at the dividing surface SP can be secured.

  When the temperature obtained by adding the second predetermined temperature (α2) to the inner wall temperature is lower than the outer wall temperature, the control unit 6 returns to the lift amount holding step S5 again and the holding of the lift amount is repeated for a predetermined period.

On the other hand, when the temperature obtained by adding the second predetermined temperature (α2) to the inner wall temperature is equal to or higher than the outer wall temperature, the control unit 6 compares the lift amount of the governor 5 at that time with the order lift amount ( Second lift comparison step S9).
If the lift amount of the governor 5 at that time is not equal to the order lift amount, the process returns to the above-described governor control restart step S7, and the lift amount control of the governor 5 according to the time schedule is continued.
On the other hand, when the lift amount of the governor 5 at that time is equal to the order lift amount, the deceleration control by the control unit 6 ends.

Next, the simulation result of the temperature change of the passenger compartment when the deceleration control of this embodiment is performed will be described.
Here, when the navigation speed of the ship is reduced to a navigation speed corresponding to the port navigation ship speed FULL in about 45 minutes, and the first predetermined temperature (α1) and the second predetermined temperature (α2) are about 50 ° C. The simulation is applied.

FIG. 11 is a graph for explaining temperature changes of the inner wall surface and the outer wall surface of the passenger compartment in the vicinity of the inlet of the high-pressure turbine in the present embodiment. FIG. 12 is a graph for explaining a change in the temperature difference between the inner wall surface and the outer wall surface in the vicinity of the inlet of the high-pressure turbine according to the related art and this embodiment.
First, based on FIG. 11 and FIG. 12, the temperature change of the point HI on the inner wall surface of the casing 3 and the point HO on the outer wall surface in the vicinity of the inlet of the high-pressure turbine 2H will be described.
Note that the positions of the points HI and HO are the same as the positions shown in FIG.

  Furthermore, the graph described by the broken line in FIG. 12 represents the temperature difference between the temperature at the point HI and the temperature at the point HO in the conventional deceleration control, and the graph described by the solid line is the point HI in the deceleration control of the present embodiment. The temperature difference between the temperature at and the temperature at point HO is shown.

  When the elapsed time at which deceleration control is started is in the vicinity of 0 minute, the temperature at the point HI is kept higher than the temperature at the point HO as in the case of the conventional deceleration control.

Thereafter, when the deceleration control is continued, the flow rate of the main steam supplied to the high-pressure turbine 2H decreases and the temperature of the main steam decreases, so the temperature at the point HI also decreases. While the deceleration control of the present embodiment is continued, that is, until about 45 minutes have elapsed after the deceleration control is started, the temperature at the point HI continues to decrease substantially constant.
And when the deceleration control of this embodiment is complete | finished, the temperature in the point HI will fall by a larger rate than before it.

On the other hand, the temperature at the point HO decreases more slowly than the temperature at the point HI, as in the case of the conventional deceleration control.
As a result, the temperature at point HI and the temperature at point HO are reversed approximately 7 minutes after the start of deceleration control.

  That is, before about 7 minutes have elapsed after the deceleration control is started, the control unit 6 repeats the governor control step S2, the first temperature comparison step S3, and the first lift comparison step S4.

  Then, before and after about 7 minutes have elapsed since the start of the deceleration control, the temperature at the point HI (inner wall surface temperature) becomes lower than the temperature at the point HO (outer wall surface temperature), so the control unit 6 performs the lift amount holding step. The process proceeds to S5, and control for holding the lift amount of the governor 5 at the lift amount at that time is started.

Thereafter, the controller 6 performs a lift amount holding step S5, a second temperature comparison step S6, a governor control restart step S7, a third temperature comparison step S8, and a second lift comparison step S9.
Therefore, the temperature at the point HI (inner wall surface temperature) and the temperature at the point HO (outer wall surface) during the deceleration control of the present embodiment, that is, until about 45 minutes have elapsed after the deceleration control is started. Temperature difference) is kept below about 50 ° C. After the deceleration control of this embodiment is completed, the temperature difference between the temperature at the point HI and the temperature at the point HO is about 50 ° C. or more.

  On the other hand, in the case of the conventional deceleration control, the temperature difference between the temperature at the point HI and the temperature at the point HO is about 50 ° C. or more when about 15 minutes have passed since the deceleration control was started. Become.

FIG. 13 is a graph for explaining temperature changes of the inner wall surface and the outer wall surface of the passenger compartment in the vicinity of the inlet of the intermediate pressure turbine in the present embodiment. FIG. 14 is a graph for explaining changes in the temperature difference between the inner wall surface and the outer wall surface in the vicinity of the inlet of the intermediate pressure turbine in the related art and in the present embodiment.
Next, based on FIG. 13 and FIG. 14, the temperature change of the point MI on the inner wall surface of the passenger compartment 3 and the point MO on the outer wall surface in the vicinity of the inlet of the intermediate pressure turbine 2M will be described.
Note that the positions of the point MI and the point MO are the same as the positions shown in FIG.

  Further, the graph described by the broken line in FIG. 14 represents the temperature difference between the temperature at the point MI and the temperature at the point MO in the conventional deceleration control, and the graph described by the solid line represents the point MI in the deceleration control of the present embodiment. The temperature difference between the temperature at and the temperature at point MO is shown.

  When the elapsed time at which deceleration control is started is in the vicinity of 0 minutes, the temperature at the point MI is kept higher than the temperature at the point MO as in the case of the conventional deceleration control.

Thereafter, when the deceleration control is continued, the flow rate of the reheat steam supplied to the intermediate pressure turbine 2M decreases and the temperature of the reheat steam decreases, so that the temperature at the point MI also decreases. While the deceleration control of the present embodiment is continued, that is, until about 45 minutes have elapsed after the deceleration control is started, the temperature at the point MI continues to decrease substantially constant.
When the deceleration control of this embodiment is completed, the temperature at the point MI decreases at a rate higher than before.
In addition, compared with the temperature at the point HI related to the high-pressure turbine 2H, the temperature decrease at the point MI related to the intermediate-pressure turbine 2M is moderate because the reheat steam is supplied to the intermediate-pressure turbine 2M. .

On the other hand, the temperature at the point MO decreases more gradually than the temperature at the point MI, as in the case of the conventional deceleration control.
As a result, inversion of the temperature at the point MI and the temperature at the point MO occurs approximately 33 minutes after the start of the deceleration control.

  According to the above configuration, when the flow rate of the main steam supplied to the high-pressure turbine 2H is reduced, such as when the output of the steam turbine 1 is reduced, the space S in the dividing surface SP of the passenger compartment 3 is reduced. When the surface pressure of the adjacent region is smaller than the predetermined surface pressure, the reduction of the steam flow rate is suspended (the reduction rate is suppressed) so that the surface pressure of the region adjacent to the space S becomes equal to or higher than the predetermined surface pressure. . As a result, a decrease in the surface pressure in the region adjacent to the space S is suppressed, and even the steam turbine 1 that requires variable speed operation can prevent steam leakage from the passenger compartment 3 and improve the performance of the steam turbine 1. Can be planned.

  Specifically, when the steam turbine 1 is controlled to reduce the output of the steam turbine 1 during steady operation, program automatic acceleration or program automatic deceleration, the steam is supplied from the main boiler 4H to the high pressure turbine 2H. While the flow rate of the steam is reduced, the load of the main boiler 4H is also reduced, so that the temperature of the main steam is also reduced.

  When main steam having a temperature lower than the temperature of the inner wall surface of the passenger compartment 3 flows into the space S in which the high-pressure turbine 2H is housed, the inner steam of the inner wall surface of the passenger compartment 3 is taken away from the main steam by the main steam. Crack temperature decreases. At this time, a temperature difference is generated between the outside temperature (outer wall surface temperature) of the wall surface of the passenger compartment 3 and the temperature of the portion adjacent to the space S (inner wall surface temperature). Further, there is a temperature difference between the temperature of the bolt 42 that integrally connects the upper casing 3U and the lower casing 3L divided by the dividing plane SP and the inner wall surface temperature. That is, as compared with the outer portion of the wall surface of the passenger compartment 3 and the bolt 42, the portion adjacent to the space S on the wall surface of the passenger compartment 3 is thermally contracted from an early stage and a difference occurs in the amount of thermal contraction. Thereby, the pressing force regarding the surface pressure in the area adjacent to the space S in the divided surface SP is reduced.

On the other hand, the pressure inside the space S gradually decreases as the main steam flow rate decreases. That is, the force for expanding the dividing surface SP of the passenger compartment 3 is gradually reduced as compared with the decrease in the pressing force described above.
For these reasons, when the flow rate of steam supplied to the high-pressure turbine 2H is decreased, such as when the output of the steam turbine 1 is decreased, the surface pressure in the region adjacent to the space S in the dividing surface SP decreases. .
When the decrease in the surface pressure generated in this way becomes smaller than the predetermined surface pressure, the main steam supplied to the high-pressure turbine 2H may leak to the outside from the division surface SP through the bolt holes 41 and the like.

Therefore, when the control for holding down the decrease in the steam flow rate is performed, the outer portion of the wall surface of the passenger compartment 3 and the bolt 42 and the space S of the wall surface of the passenger compartment 3 are adjacent to each other as compared with the case before the reduction of the steam flow rate is held down. The difference in heat shrinkage between the parts is reduced. Furthermore, the pressure of the main steam supplied to the high-pressure turbine 2H is also reduced, and the force for expanding the dividing surface SP is also reduced.
For these reasons, compared to before the reduction of the steam flow rate is suspended, the surface pressure in the region adjacent to the space S in the split surface SP increases, and the steam supplied to the high-pressure turbine 2H is less likely to leak to the outside.

  Based on the comparison between the temperature (inner wall surface temperature) of the region adjacent to the space S on the dividing surface SP and the outer temperature (outer wall surface temperature), these temperatures are controlled by holding down the decrease in the steam flow rate. Control to hold down the decrease in the steam flow rate is appropriately performed as compared with the case where it is not based on the above.

Specifically, since the linear expansion coefficient of the material constituting the passenger compartment 3 is known, based on the temperature difference between the inner wall surface temperature and the outer wall surface temperature, there is a difference between the inner wall surface portion and the outer wall surface portion in the split surface SP. The difference in shrinkage amount can be obtained. Furthermore, the temperature of the bolt 42 is estimated based on the inner wall surface temperature and the outer wall surface temperature, and the contraction between the inner wall surface portion of the split surface SP and the bolt 42 based on the temperature difference between the inner wall surface temperature and the temperature of the bolt 42. The difference in quantity can be determined.
Based on these, it is possible to obtain the surface pressure of the inner wall surface portion of the divided surface SP in consideration of the change of the pressing force, and to determine whether or not the surface pressure of the inner wall surface portion of the divided surface SP is smaller than a predetermined surface pressure. .

  Compared with other methods of measuring the surface pressure of the inner wall surface portion of the dividing surface SP, the temperature can be easily measured, so it is possible to easily determine whether or not to perform control to hold down the reduction of the steam flow rate. .

Note that the steam flow rate can be reduced without measuring the inner wall surface temperature and the outer wall surface temperature by acquiring in advance the operational state of the steam turbine 1 and the relationship between the surface pressures of the inner wall surface portions of the split surface SP. It is possible to directly carry out the hold control.
Alternatively, by previously acquiring the relationship between the inner wall surface temperature and the outer wall surface temperature, and the surface pressure of the inner wall surface portion of the split surface SP, the control for holding down the reduction of the steam flow rate based on the inner wall surface temperature and the outer wall surface temperature. It is also possible to determine whether or not to perform the calculation without performing the calculation for obtaining the surface pressure.

After the lift amount holding step S5 is performed, that is, after the first predetermined period for holding the lift amount has elapsed, based on whether the temperature obtained by adding the predetermined temperature to the inner wall surface temperature is less than the outer wall surface temperature, The control for suspending the decrease in the steam flow rate is terminated and the control for reducing the steam flow rate is resumed, or the determination is made again whether the control for suspending the decrease in the steam flow rate is performed for a predetermined period.
By doing in this way, compared with the case where it judges based on whether an inner wall surface temperature is less than an outer wall surface temperature, the control which reduces a steam flow rate at an earlier stage can be restarted.

1 Steam turbine 2H Steam high pressure turbine (turbine)
3 Cabin 4H Main boiler (boiler)
5 Governor (adjustment part)
6 Control unit (turbine remote control)
7 Control unit (main boiler / reheater control)
S space SP division surface 31H high pressure side inlet inner wall temperature sensor (surface pressure information acquisition means, temperature measurement unit)
32H High pressure side inlet outer wall temperature sensor (surface pressure information acquisition means, temperature measurement unit)
S2 Governor control step (flow reduction step)
S3 First temperature comparison step (comparison step)
S5 Lift amount holding step (decrease rate adjusting step)

Claims (6)

A vehicle interior having a space for accommodating the turbine and a split surface;
An adjustment unit for adjusting a flow rate of steam supplied to the turbine;
When the flow rate of steam supplied to the turbine is decreased, the rate of decrease of the steam flow rate with respect to the adjustment unit so that the surface pressure in the region adjacent to the space on the dividing surface is equal to or higher than a predetermined surface pressure. A control unit for performing control to adjust
A steam turbine characterized in that is provided. At least surface pressure information acquisition means for acquiring information on the surface pressure of the area adjacent to the space in the divided surface is provided,
The control unit controls the reduction rate of the steam flow rate based on the acquired information on the surface pressure so that the surface pressure of the region adjacent to the space on the divided surface is equal to or higher than a predetermined surface pressure. The steam turbine according to claim 1. The surface pressure information acquisition means is a temperature measurement unit that measures a temperature of a region adjacent to the space on the divided surface and a temperature outside the divided surface,
The controller controls the steam flow rate so that the surface pressure of the region adjacent to the space on the dividing surface is equal to or higher than a predetermined surface pressure based on the temperature of the region adjacent to the space and the outside temperature. The steam turbine according to claim 2, wherein a rate of decrease of the steam is controlled. The controller, after performing the steam flow rate reduction rate control only for a predetermined period,
When the temperature obtained by adding a predetermined temperature to the temperature of the area adjacent to the space is lower than the outside temperature, the steam flow rate reduction rate control is terminated,
The steam turbine according to claim 3, wherein when the temperature obtained by adding a predetermined temperature to the temperature of the region adjacent to the space is equal to or higher than the outside temperature, the steam flow rate reduction rate control is continued. .   The said control part performs control which adjusts the decreasing rate of the said steam flow rate by withholding the reduction | decrease of the said steam flow rate with respect to the said adjustment part, The Claim 1 characterized by the above-mentioned. Steam turbine. A flow rate reduction step for reducing the flow rate of steam supplied to the turbine based on instructions from the outside;
A comparison step of acquiring information related to the surface pressure of the divided surface in the passenger compartment that houses the turbine, and comparing whether or not the surface pressure estimated based on the acquired surface pressure information is smaller than a predetermined surface pressure. When,
When the estimated surface pressure is smaller than the predetermined surface pressure, a decreasing rate adjustment step of adjusting the decreasing rate of the steam flow rate;
A method for operating a steam turbine, comprising:

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