JP5968260B2 - Marine steam turbine and cooling method for turbine casing - Google Patents

Description

  The present invention relates to a marine steam turbine, and more particularly to a marine steam turbine used as a marine vessel propulsion turbine (marine main engine turbine) and a cooling method for the turbine casing.

  As a marine steam turbine used as a marine propulsion turbine, for example, the one described in Patent Document 1 is known.

JP 2009-30486 A

  Now, in the marine steam turbine described in Patent Document 1, a high temperature (for example, 550 ° C. to 560 ° C.) flows from the main steam inlet portion provided at the center of the upper surface of the upper casing toward the inlet of the high pressure turbine. The nozzle chamber and the dummy ring are heated by the steam, and the main steam introduction part of the upper compartment (more specifically, high-pressure steam supplied from a steam generator (not shown) is The part that flows into the passenger compartment, more specifically, the nozzle box, is heated, and the temperature difference between the upper compartment and the lower compartment is likely to occur. When the temperature of the upper compartment becomes higher than the temperature of the lower compartment, a phenomenon that the entire compartment is curved upwardly, that is, a so-called cat warp (catsback) of the compartment occurs. The cat warp in the passenger compartment reduces the clearance between the stationary part of the lower compartment and the rotor, and the cat warp of the excessive passenger compartment causes the stationary part of the lower compartment and the rotor to contact each other. .

  Therefore, in recent years, a part of the steam (steam whose temperature has decreased) immediately after passing through the turbine blades of the high-pressure governing stage (high-pressure first and second stages) is extracted, and the upper casing is cooled with this steam. A vehicle compartment cooling device has been proposed in which the temperature difference between the vehicle compartment and the lower compartment is reduced to reduce cat warpage in the vehicle compartment.

  In this passenger compartment cooling device, for example, when the marine steam turbine is in rated operation (when a vessel equipped with the marine steam turbine and the passenger compartment cooling device navigates the ocean at a cruising speed), the upper compartment and the lower compartment It is preferable that the upper casing is cooled so that the temperature difference from the casing is the smallest and the efficiency of the marine steam turbine is the highest.

  However, when the marine steam turbine and the cabin cooling device are actually mounted on a marine vessel and the marine steam turbine is rated, the temperature difference between the upper cabin and the lower cabin may be more than expected.

  In recent years, in order to reduce fuel costs, a ship equipped with a marine steam turbine and a cabin cooling device is navigating the open ocean at a speed slower than the cruise speed. That is, when a ship equipped with a marine steam turbine and a passenger compartment cooling system navigates the open ocean at a cruise speed, that is, when the upper passenger compartment is cooled on the assumption that the marine steam turbine is rated. When a ship equipped with a turbine and a cabin cooling device navigates the open ocean at a speed slower than the cruise speed, the temperature difference between the upper and lower cabins may exceed an allowable value (for example, 50 ° C.). is there.

  In addition, marine steam turbines, unlike land steam turbines used in power plants, have a lower load than rated operations when ships equipped with marine steam turbines and cabin cooling devices navigate the port. May be operated for a long time in the state. Therefore, when a ship equipped with a marine steam turbine and a passenger compartment cooling device navigates a harbor, the temperature difference between the upper compartment and the lower compartment may exceed an allowable value (for example, 50 ° C.). In addition, unlike land steam turbines, load fluctuations may occur depending on the operational status of the ship, so the temperature difference between the upper compartment and the lower compartment may exceed an allowable value (for example, 50 ° C.).

  The present invention has been made to solve the above-described problems, and is based on the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment. Accordingly, the marine steam turbine capable of actively changing the flow rate of the steam passing through the inner surface of the nozzle box and the outer surface of the dummy ring and cooling the nozzle box and the dummy ring, and cooling of the turbine casing It aims to provide a method.

The present invention employs the following means in order to solve the above problems.
A marine steam turbine according to the present invention is a marine steam turbine driven by a plurality of steams having different pressures, and includes a turbine casing and a plurality of turbine blades, and the plurality of turbine blades are turbines. A high-pressure turbine blade that obtains power by high-pressure steam among the plurality of steams having different pressures flowing through the passenger compartment, and a low-pressure turbine that obtains power by steam having a lower pressure than the steam flowing through the high-pressure turbine blades A blade, and
The first steam supply passage for supplying the high-pressure steam from the upper part of the turbine casing to the plurality of turbine blades, and the pressure by passing through the high-pressure side turbine blade among the plurality of turbine blades. A second steam supply passage for supplying the low pressure side turbine blade with the steam having a reduced pressure while cooling the upper portion of the turbine casing by the steam having a reduced pressure, and a middle of the second steam supply passage. And a cooling steam flow rate control valve that controls the flow rate of the steam whose pressure is low and that flows through the second steam supply passage.

According to the marine steam turbine of the present invention, the difference between the temperature of the upper casing and the temperature of the lower casing, or the difference between the steam temperature in the upper casing and the steam temperature in the lower casing is less than an allowable value (for example, The opening degree of the cooling steam flow control valve is adjusted so as to be 50 ° C. or lower (more preferably 40 ° C. or lower).
Thus, depending on the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment, the inner surface of the nozzle box and the outer surface of the dummy ring The flow rate of the steam for cooling the nozzle box and the dummy ring can be actively changed.

  In the marine steam turbine, the first temperature sensor that measures the temperature of the upper portion of the turbine casing, the second temperature sensor that measures the temperature of the lower portion of the turbine casing, the first temperature sensor, and the Based on the measured value sent from the second temperature sensor, the difference between the temperature of the upper part of the turbine casing and the temperature of the lower part of the turbine casing is calculated, and the cooling steam flow rate is calculated based on the calculated result. It is more preferable to include a controller that controls the opening degree of the control valve.

According to such a marine steam turbine, based on the measurement values sent from the first temperature sensor and the second temperature sensor, the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the upper car The opening degree of the cooling steam flow control valve is controlled by the controller so that the difference between the steam temperature in the room and the steam temperature in the lower passenger compartment is less than an allowable value (for example, 50 ° C. or less (more preferably 40 ° C. or less)). It will be adjusted automatically.
Thereby, the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment is less than an allowable value (for example, 50 ° C. or less (more preferably, It is possible to automate the system for cooling the upper compartment so that it becomes 40 ° C. or lower)

  In the marine steam turbine, a drain pipe that is provided in the middle of the second steam supply passage, and that directly guides the steam having a reduced pressure flowing through the second steam supply passage to a condenser, and in the middle of the drain pipe It is further preferable that a drain valve that is provided and opened when a difference between an upper temperature of the turbine casing and a lower temperature of the turbine casing exceeds an allowable value is provided.

According to such a marine steam turbine, the difference between the temperature of the upper casing and the temperature of the lower casing, or the difference between the steam temperature in the upper casing and the steam temperature in the lower casing is an allowable value (for example, 50 ° C. When the cooling steam flow rate control valve is fully open, the drain valve is forcibly opened from the fully closed state.
That is, the steam existing (stagnation) between the inner surface of the nozzle box and the outer surface of the dummy ring is led to the condenser, and the temperature of the upper compartment or the upper compartment is lowered. The difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment becomes small.
Thereby, the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment is less than an allowable value (for example, 50 ° C. or less (more preferably, 40 ° C. or less)).

  A method for cooling a turbine casing of a marine steam turbine according to the present invention includes a step of introducing high-pressure steam among a plurality of steams having different pressures to a plurality of turbine blades, and a high-pressure side of the plurality of turbine blades. Cooling the turbine casing upper part with steam whose pressure has been reduced by passing through the turbine blades, and further cooling the upper part of the turbine casing. A step of guiding the steam after being performed to a low-pressure side turbine blade among the plurality of turbine blades, a step of measuring a temperature of an upper portion of the turbine casing, and a temperature of a lower portion of the turbine casing; Based on the difference between the temperature of the upper part and the lower part of the turbine casing, the turbine blade is guided to the low-pressure side turbine blade among the plurality of turbine blades. And controlling the amount of steam after the serial turbine casing upper part of the cooling, and a.

According to the method for cooling a turbine casing of a marine steam turbine according to the present invention, the difference between the temperature of the upper casing and the temperature of the lower casing, or the difference between the steam temperature in the upper casing and the steam temperature in the lower casing. Of the cooling steam flow rate control valve is adjusted so that is below an allowable value (for example, 50 ° C. or less (more preferably 40 ° C. or less)).
Thus, depending on the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment, the inner surface of the nozzle box and the outer surface of the dummy ring The flow rate of the steam for cooling the nozzle box and the dummy ring can be actively changed.

  In the method for cooling a turbine casing of a marine steam turbine, the steam after further cooling the upper part of the turbine casing is condensed based on the difference between the temperature of the upper part of the turbine casing and the lower part of the turbine casing. It is more preferable that the method includes a step of leading to a vessel.

  According to such a cooling method for the turbine casing of the marine steam turbine, a flow from the upper part of the passenger compartment where high-temperature steam stays to the lower part of the passenger compartment can be achieved, and the equalization of the upper and lower temperatures of the passenger compartment can be promoted.

  In the method for cooling a turbine casing of a marine steam turbine, the turbine guided to a low-pressure turbine blade among the plurality of turbine blades based on a difference between an upper temperature of the turbine casing and a lower portion of the turbine casing. If the difference between the temperature of the upper part of the turbine casing and the lower part of the turbine casing exceeds the allowable value even if the entire amount of steam after cooling the upper part of the casing is guided to the low-pressure side turbine blade, It is more preferable to provide a step of guiding the steam after cooling the upper portion of the turbine casing to the condenser.

According to such a cooling method for the turbine casing of a marine steam turbine, the difference between the temperature of the upper casing and the temperature of the lower casing, or the difference between the steam temperature in the upper casing and the steam temperature in the lower casing is reduced. When the allowable value (for example, 50 ° C. (more preferably 40 ° C.)) is exceeded and the cooling steam flow control valve is fully open, the drain valve is forced to be fully closed to fully open. Become.
That is, the steam existing (stagnation) between the inner surface of the nozzle box and the outer surface of the dummy ring is led to the condenser, and the temperature of the upper compartment or the upper compartment is lowered. The difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment becomes small.
Thereby, the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment is less than an allowable value (for example, 50 ° C. or less (more preferably, 40 ° C. or less)).

  In the cooling method for the turbine casing of the marine steam turbine, when the difference between the temperature of the upper part of the turbine casing and the lower part of the turbine casing falls within an allowable range, It is more preferable to provide a step of reducing the amount of steam guided to the condenser after the reduction.

  According to such a cooling method for the turbine casing of the marine steam turbine, the amount of heat thrown away into the seawater can be minimized.

  According to the marine steam turbine and the method for cooling the turbine casing according to the present invention, the upper portion of the turbine casing can be appropriately cooled in any operation state. Further, since the flow rate of the steam for cooling the upper part of the turbine casing can be actively changed according to the difference between the temperature of the upper part of the turbine casing and the temperature of the lower part of the turbine casing, the turbine can be efficiently The upper part of the passenger compartment can be cooled. As a result, cat warpage in the passenger compartment can be prevented, and contact between the stationary part arranged in the passenger compartment and the turbine rotor can be avoided.

It is a longitudinal section showing one embodiment of a marine steam turbine concerning the present invention. It is a figure which expands and shows the principal part of FIG.

Hereinafter, a marine steam turbine according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, a marine steam turbine 41 according to the present embodiment is configured with a turbine rotor 2 and a casing 3 that accommodates the turbine rotor 2 as main elements.
The turbine rotor 2 is arranged (arranged) along the axial direction of the rotary shaft 6, and each end portion is rotatably supported by a support portion (bearing base) 5 via a bearing 4. And a plurality of turbine disks 7a and 7b. The turbine disk 7a is a plurality of (high pressure side) turbine disks arranged on one side of the rotary shaft 6 (the high pressure side located on the right side in FIG. 1), and the turbine disk 7b is the other side of the rotary shaft 6 ( 1, there are a plurality of (intermediate pressure side or low pressure side) turbine disks 7b arranged on the intermediate pressure side (or low pressure side) located on the left side of the turbine disk 7b. Turbine blades (moving blades) 8a and 8b are attached along the circumferential direction with a predetermined gap.

  The vehicle interior 3 is a horizontally divided vehicle compartment made of, for example, high chrome steel (9Cr cast steel, 12Cr cast steel, etc.) and divided in the vertical direction (having a half structure). The upper casing 3a is located on the upper side, and the lower casing 3b is located on the lower side in FIG. 1, and the inner peripheral surfaces of the upper casing 3a and the lower casing 3b are respectively connected to the rotating shaft 6. A plurality of annular partition plates 9a and 9b are arranged along the axial direction. The partition plate 9a is a multi-stage (high-pressure side) partition plate disposed corresponding to the turbine disk 7a and the turbine blade 8a, and a nozzle for ejecting steam toward the moving blade 8a is disposed on the ring. The structure can be divided by a horizontal plane including the center. The partition plate 9b is a multi-stage (intermediate pressure side or low pressure side) partition plate arranged corresponding to the turbine disk 7b and the turbine blade 8b, and a nozzle for ejecting steam toward the moving blade 8b is provided on the ring. It has a structure that can be divided by a horizontal plane including the center. The upper casing 3a is placed so as to cover the opening of the lower casing 3b, and is fixed to the lower casing 3b via a plurality of bolts (not shown), whereby one side of the marine steam turbine 41 ( A first turbine casing space (high pressure side turbine casing) in which turbine disks 7a, turbine blades 8a, and partition plates 9a are alternately arranged in the axial direction of the rotary shaft 6 on the high pressure side located on the right side in FIG. A space 10 is formed, and on the other side of the marine steam turbine 41 (the intermediate pressure side (or low pressure side) located on the left side in FIG. 1), the turbine disk 7 b, the turbine blade 8 b, and the partition plate 9 b are in the axial direction of the rotary shaft 6. The second turbine casing space (intermediate pressure side (or low pressure side) turbine casing space) 11 arranged alternately is formed.

  The first turbine casing space is located between the first turbine casing space 10 and the second turbine casing space 11, that is, in the casing 3 positioned substantially at the center in the axial direction of the rotary shaft 6. A dummy ring (partition member) 12 that partitions (partitions) 10 and the second turbine casing space 11 is disposed in the circumferential direction. The dummy ring 12 is an annular member made of, for example, low chrome steel (such as 2Cr cast steel) or high chrome steel (such as 9Cr cast steel or 12Cr cast steel), and is divided into, for example, two parts in the vertical direction (half structure) It is composed of two semicircular members. Further, the speed control stage nozzle 18 and the stationary blade 19 are incorporated in the dummy ring 12 to integrally form the nozzle chamber 20.

High-pressure steam supplied from a steam generator (not shown) flows from the upper part of the turbine casing, and is supplied to the plurality of turbine blades 8 a through the first steam supply passage 22. More specifically, a main steam inlet portion 13 is provided at the center of the upper surface of the upper casing 3 a, and a forward nozzle valve 14 is disposed in the main steam inlet portion 13. The main steam that has passed through the forward nozzle valve 14 passes through the speed-regulating stage nozzle 18 and the stationary blade 19 that are fitted in the dummy ring 12, and then in the first turbine casing space 10 (and more Turbine blades 8a). Further, a high-pressure turbine exhaust 15 is provided at one end of the lower surface of the lower casing 3b (the end located on the right side in FIG. 1).
On the other hand, a reheat steam inlet 16 is provided at the center of the lower surface of the lower casing 3b, and an intermediate pressure is provided at the other end of the lower surface of the lower casing 3b (the end located on the left side in FIG. 1). A turbine exhaust part 17 is provided.

As shown in FIG. 1 or FIG. 2, the passenger compartment cooling device 51 according to the present embodiment includes a second steam supply passage (bypass steam pipe) 52, a cooling steam flow control valve (regulation valve) 53, A (first) temperature sensor T1, a (second) temperature sensor T2, a turbine remote controller 54, a drain pipe 55, an orifice 56, and a drain valve 57 are provided.
The second steam supply passage 52 is extracted immediately after passing through the high-pressure turbine blade (more specifically, the turbine blade 8a of the high-pressure governing stage (high-pressure first and second stages)), and the nozzle box 21 After being led between the inner surface of the nozzle ring 21 and the outer surface of the dummy ring 12, the steam that has cooled the nozzle box 21 and the dummy ring 12 passes between the inner surface of the nozzle box 21 and the outer surface of the dummy ring 12. (That is, the steam whose pressure has been lowered by passing through the high-pressure turbine blade) is converted into the low-pressure turbine blade (more specifically, the turbine blade 8a in the high-pressure intermediate stage (high-pressure fourth stage in this embodiment)). It is a pipe that leads to

  The cooling steam flow rate control valve 53 is provided in the middle of the second steam supply passage 52, and the flow rate of the steam flowing through the second steam supply passage 52, that is, the partition plate 9a positioned at the highest pressure control stage and the most upstream. The nozzle box 21 and the dummy ring 12 are cooled by passing through between the inner surface of the nozzle box 21 and the outer surface of the dummy ring 12, and in the middle of the high pressure (in this embodiment, the high pressure fourth stage). ) Is a valve that controls (adjusts) the flow rate of the steam guided to the turbine blade 8a, and is opened and closed (the opening degree is controlled (adjusted)) by a control signal sent from the turbine remote controller 54. ing.

The temperature sensor T1 is a sensor that is attached to the central portion of the upper surface of the upper casing 3a, more specifically, the upper casing 3a located in the vicinity of the nozzle box 21, and measures the temperature of the upper casing 3a. The measured value α measured by the sensor T1 is sent to the turbine remote controller 54. The temperature sensor T1 is provided to measure the temperature of the upper part of the turbine casing. The temperature of the upper part of the turbine casing is the temperature of the upper wall surface of the turbine casing or the vicinity of the wall surface, or the turbine wheel. Refers to the temperature of steam flowing through the upper part of the chamber. That is, the temperature sensor T1 only needs to be able to measure the temperature of the upper portion of the turbine casing, and the installation position is not limited to the center of the upper surface of the upper casing 3a.
The temperature sensor T2 is attached to the center of the lower surface of the lower casing 3b, more specifically, the bottom of the lower casing 3b located on the side opposite to the nozzle box 21, and measures the temperature of the lower casing 3b. The measured value β measured by the temperature sensor T2 is sent to the turbine remote controller 54.
The temperature sensor T2 is provided to measure the temperature of the lower portion of the turbine casing, and the temperature of the lower portion of the turbine casing is the temperature of the lower wall surface of the turbine casing or the vicinity of the wall surface or the lower portion of the turbine casing. Refers to the temperature of the steam flowing through. That is, the temperature sensor T2 only needs to be able to measure the temperature of the upper part of the turbine casing, and the installation position is not limited to the bottom of the lower casing 3b.

The turbine remote controller 54 calculates the temperature difference (α−β) between the upper casing 3a and the lower casing 3b based on the measured values α, β sent from the temperature sensors T1, T2, and the calculated result. Is a controller that controls the opening degree of the cooling steam flow rate control valve 53 by sending a control signal based on the above to the cooling steam flow rate control valve 53.
In the cooling steam flow control valve 53, the temperature difference between the upper casing 3a and the lower casing 3b becomes 50 ° C. or less (more preferably 40 ° C. or less) by a control signal sent from the turbine remote controller 54. Thus, the opening degree is controlled.
Here, the reason why the opening degree is controlled so that the temperature difference between the upper casing 3a and the lower casing 3b is 50 ° C. or less (more preferably 40 ° C. or less) is that there is no particular nonconformity. Similar measurement results in the conventional non-reheated marine turbine are about 30 ° C. to 40 ° C., and even in the reheat turbine, about 50 ° C. is set as an initial value to target this level.

One end (upstream end) of the drain pipe 55 is connected to the center of the lower surface of the lower casing 3b, and the other end (downstream end) is connected to the condenser. This is a pipe that directly guides (stagnates) steam between the surface and the condenser, and an orifice 56 and a drain valve 57 are connected in order from the upstream side to the downstream side.
The orifice 56 is provided to prevent excessive flow of steam into the condenser when the drain valve 57 is opened.
Here, “the steam flows excessively into the condenser” means that steam equivalent to about 1200 kg / h flows into the condenser, and when the φ56 mm orifice 56 is equipped, about 150 kg / h. Of steam will flow into the condenser.
The drain valve 57 is forcibly opened from the closed state when the temperature difference between the upper casing 3a and the lower casing 3b exceeds 50 ° C. and the cooling steam flow control valve 53 is open. This is an on-off valve that is closed from being opened when the temperature difference between the upper casing 3a and the lower casing 3b becomes 50 ° C. or less.
The drain valve 57 is normally closed.

According to the marine steam turbine 41 according to the present embodiment, the difference between the temperature of the upper casing 3a and the temperature of the lower casing 3b is less than an allowable value (for example, 50 ° C. or less (more preferably 40 ° C. or less)). Thus, the opening degree of the cooling steam flow rate control valve 53 is adjusted.
Thus, according to the difference between the temperature of the upper casing 3a and the temperature of the lower casing 3b, the nozzle box 21 and the dummy ring 12 pass through between the inner surface of the nozzle box 21 and the outer surface of the dummy ring 12. The flow rate of the cooling steam can be actively changed.

Further, according to the marine steam turbine 41 according to the present embodiment, the difference between the temperature of the upper casing 3a and the temperature of the lower casing 3b is based on the measured values sent from the temperature sensor T1 and the temperature sensor T2. The opening degree of the cooling steam flow control valve 53 is automatically adjusted by the turbine remote controller 54 so as to be equal to or less than an allowable value (for example, 50 ° C. or less (more preferably 40 ° C. or less)).
Thereby, the upper casing 3a is cooled so that the difference between the temperature of the upper casing 3a and the temperature of the lower casing 3b is not more than an allowable value (for example, 50 ° C. or less (more preferably 40 ° C. or less)). The system can be automated.

Furthermore, according to the marine steam turbine 41 according to the present embodiment, the difference between the temperature of the upper casing 3a and the temperature of the lower casing 3b exceeds an allowable value (for example, 50 ° C. (more preferably 40 ° C.)). In addition, when the cooling steam flow control valve 53 is fully open, the drain valve 57 is forcibly opened from the closed state.
That is, the steam existing (stagnation) between the inner surface of the nozzle box 21 and the outer surface of the dummy ring 12 is led to the condenser, and the temperature of the upper casing 3a is lowered, so that the upper casing is reduced. The difference between the temperature of 3a and the temperature of the lower compartment is reduced.
Thereby, the difference between the temperature of the upper casing 3a and the temperature of the lower casing 3b can be kept below an allowable value (for example, 50 ° C. or lower (more preferably 40 ° C. or lower)).

Here, the cooling method of the turbine casing of the marine steam turbine according to the present embodiment includes a step of introducing high-pressure steam among a plurality of steams having different pressures to the plurality of turbine blades 8a, and the plurality of turbines. among the blades 8 a, a step for cooling the turbine casing upper by steam pressure becomes lower by passing through the high pressure side turbine blades 8a, in the cooling method of the turbine casing of marine steam turbines with further a step of directing the steam after cooling of the upper part of the turbine casing to the low pressure side turbine blade 8 a of the plurality of turbine blades 8 a, the upper portion of the turbine casing temperature, and the lower portion of the turbine casing measuring a temperature of, based on the difference between the lower temperature and the turbine casing of the upper part of the turbine casing, the plurality of turbine blades 8 And a, and controlling the amount of steam after the turbine casing upper part of the cooling led to the low-pressure side turbine blade 8 a of.

According to the cooling method of the turbine casing of the marine steam turbine 41 according to the present embodiment, the difference between the temperature of the upper casing and the temperature of the lower casing, or the steam temperature in the upper casing and the steam temperature in the lower casing The degree of opening of the cooling steam flow control valve is adjusted so that the difference between the two is less than the allowable value (for example, 50 ° C. or less (more preferably 40 ° C. or less)).
Thus, depending on the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment, the inner surface of the nozzle box and the outer surface of the dummy ring The flow rate of the steam for cooling the nozzle box and the dummy ring can be actively changed.

  In the cooling method of the turbine casing of the marine steam turbine 41, the steam after the cooling of the turbine casing upper part is further recovered based on the difference between the temperature of the upper part of the turbine casing and the lower part of the turbine casing. It is more preferable to provide a step of leading to a water vessel.

  According to such a cooling method of the turbine casing of the marine steam turbine 41, the flow from the upper part of the passenger compartment where high-temperature steam stays to the lower part of the passenger compartment can be performed, and the equalization of the temperature above and below the passenger compartment can be promoted.

  In the cooling method of the turbine casing of the marine steam turbine 41, the temperature guided to the low-pressure turbine blade among the plurality of turbine blades based on the difference between the temperature of the upper portion of the turbine casing and the lower portion of the turbine casing. Even if the entire amount of steam after cooling the turbine casing upper part is guided to the low-pressure turbine blade, the difference between the temperature of the upper part of the turbine casing and the lower part of the turbine casing exceeds the allowable value, More preferably, the method further comprises a step of guiding the steam after cooling the upper portion of the turbine casing to a condenser.

According to such a cooling method of the turbine casing of the marine steam turbine 41, the difference between the temperature of the upper casing and the temperature of the lower casing, or the difference between the steam temperature in the upper casing and the steam temperature in the lower casing. When the pressure exceeds the allowable value (for example, 50 ° C. (more preferably 40 ° C.)) and the cooling steam flow control valve is fully open, the drain valve is forced to be fully closed to fully open. become.
That is, the steam existing (stagnation) between the inner surface of the nozzle box and the outer surface of the dummy ring is led to the condenser, and the temperature of the upper compartment or the upper compartment is lowered. The difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment becomes small.
Thereby, the difference between the temperature of the upper compartment and the temperature of the lower compartment, or the difference between the steam temperature in the upper compartment and the steam temperature in the lower compartment is less than an allowable value (for example, 50 ° C. or less (more preferably, 40 ° C. or less)).

  In the cooling method of the turbine casing of the marine steam turbine 41, when the difference between the temperature of the upper part of the turbine casing and the lower part of the turbine casing falls within an allowable range, the amount of steam guided to the low-pressure turbine blade It is more preferable to provide a step of reducing the amount of steam guided to the condenser after reducing the amount of water.

  According to such a cooling method for the turbine casing of the marine steam turbine, the amount of heat thrown away into the seawater can be minimized.

In addition, this invention is not limited to embodiment mentioned above, It can also implement by changing and changing suitably as needed.
For example, in the above-described embodiment, the difference between the temperature of the upper casing 3a and the temperature of the lower casing 3b and the difference between the temperature of the upper casing 3a itself and the temperature of the lower casing 3b itself are obtained as temperature differences. The present invention is not limited to this, and the difference between the steam temperature in the upper casing 3a and the steam temperature in the lower casing 3b may be obtained as a temperature difference.

  In the above-described embodiment, the cooling steam flow control valve 53 is connected to the middle of the second steam supply passage 52 as a specific example. However, the present invention is not limited to this. In place of the second steam supply passage 52, a second steam supply passage 52 having an inner diameter larger than the inner diameter of the second steam supply passage 52 is prepared. The cooling steam flow control valve 53 may be connected to an orifice (orifice 56 is used for a different purpose and improves the flow controllability by the steam flow control valve).

3 casing 3a upper casing 8a turbine blade 10 (first) turbine casing space 12 dummy ring 13 main steam inlet 14 forward nozzle valve 18 governing stage nozzle 21 nozzle box 41 marine steam turbine 52 bypass steam pipe 53 cooling Steam flow control valve 54 Turbine remote control (controller)
55 Drain pipe 57 Drain valve T1 (first) temperature sensor T2 (second) temperature sensor α measured value β measured value

Claims (7)

A marine steam turbine driven by a plurality of steams having different pressures,
A turbine casing and a plurality of turbine blades;
The plurality of turbine blades have a high pressure side turbine blade that obtains power by steam having a high pressure among the plurality of steams having different pressures flowing through the turbine casing, and a pressure lower than that of the steam flowing through the high pressure side turbine blades. A low-pressure turbine blade that is powered by steam,
A first steam supply passage for supplying the high-pressure steam to the plurality of turbine blades from an upper part of the turbine casing;
Among the plurality of turbine blades, the steam whose pressure has been reduced in the low-pressure turbine blade while cooling the upper portion of the turbine casing by steam whose pressure has been reduced by passing through the high-pressure turbine blade. A second steam supply passage for supplying,
A cooling steam flow control valve that is provided in the middle of the second steam supply passage and controls the flow rate of the steam having the reduced pressure flowing through the second steam supply passage;
A first temperature sensor for measuring a temperature of an upper portion of the turbine casing;
A second temperature sensor for measuring a temperature at a lower portion of the turbine casing;
Based on the measured values sent from the first temperature sensor and the second temperature sensor, the difference between the temperature of the upper part of the turbine casing and the temperature of the lower part of the turbine casing is calculated and calculated. A controller for controlling the opening degree of the cooling steam flow rate control valve based on the result;
A marine steam turbine characterized by comprising: A drain pipe that is provided in the middle of the second steam supply passage, and that directly guides the steam having the reduced pressure flowing through the second steam supply passage to a condenser;
A drain valve provided in the middle of the drain pipe and opened when a difference between an upper temperature of the turbine casing and a lower temperature of the turbine casing exceeds an allowable value; The marine steam turbine according to claim 1 . A marine steam turbine driven by a plurality of steams having different pressures,
A turbine casing and a plurality of turbine blades;
The plurality of turbine blades have a high pressure side turbine blade that obtains power by steam having a high pressure among the plurality of steams having different pressures flowing through the turbine casing, and a pressure lower than that of the steam flowing through the high pressure side turbine blades. A low-pressure turbine blade that is powered by steam,
A first steam supply passage for supplying the high-pressure steam to the plurality of turbine blades from an upper part of the turbine casing;
Among the plurality of turbine blades, the steam whose pressure has been reduced in the low-pressure turbine blade while cooling the upper portion of the turbine casing by steam whose pressure has been reduced by passing through the high-pressure turbine blade. A second steam supply passage for supplying,
A cooling steam flow control valve that is provided in the middle of the second steam supply passage and controls the flow rate of the steam having the reduced pressure flowing through the second steam supply passage;
A drain pipe that is provided in the middle of the second steam supply passage, and that directly guides the steam having the reduced pressure flowing through the second steam supply passage to a condenser;
A drain valve provided in the middle of the drain pipe and opened when a difference between an upper temperature of the turbine casing and a lower temperature of the turbine casing exceeds an allowable value;
A marine steam turbine characterized by comprising: Introducing a high-pressure steam among a plurality of steams having different pressures to a plurality of turbine blades;
A method of cooling a turbine casing of a marine steam turbine, comprising: a step of cooling the upper portion of the turbine casing with steam whose pressure is reduced by passing through the high-pressure side turbine blade among the plurality of turbine blades. ,
Further, the step of guiding the steam after cooling the upper portion of the turbine casing to the low-pressure side turbine blade among the plurality of turbine blades;
Measuring the temperature at the top of the turbine casing and the temperature at the bottom of the turbine casing;
Steam after cooling the upper part of the turbine casing led to the low-pressure turbine blade among the plurality of turbine blades based on the difference between the temperature of the upper part of the turbine casing and the lower part of the turbine casing And a method of cooling the turbine casing of the marine steam turbine.   Based on the difference between the temperature of the upper portion of the turbine casing and the lower portion of the turbine casing, the method further comprises the step of guiding the steam after cooling the upper portion of the turbine casing to a condenser. The method for cooling a turbine casing of a marine steam turbine according to claim 4.   Based on the difference between the temperature at the upper part of the turbine casing and the lower part of the turbine casing, the total amount of steam after cooling the upper part of the turbine casing led to the low-pressure turbine blade among the plurality of turbine blades When the difference between the temperature of the upper part of the turbine casing and the lower part of the turbine casing exceeds the allowable value even if the turbine is guided to the low-pressure side turbine blade, the steam after cooling the upper part of the turbine casing is The method for cooling a turbine casing of a marine steam turbine according to claim 5, further comprising a step of guiding the condenser.   When the difference between the temperature at the upper part of the turbine casing and the lower part of the turbine casing falls within the allowable range, the amount of steam introduced to the low-pressure side turbine blade is reduced, and then the steam introduced to the condenser is reduced. The method for cooling a turbine casing of a marine steam turbine according to claim 6, further comprising a step of reducing the amount.

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