JP4424970B2 - Steam turbine ship main turbine speed-up method and speed-up equipment - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a main turbine speed increasing method and speed increasing device at the time of departure of a steam turbine ship, and more particularly to a main turbine speed increasing method and speed increasing device for speed increasing control so as to enable quick port departure. It is.

Conventionally, a main turbine in a steam turbine ship such as an LNG ship is kept at a predetermined temperature by supplying warm-up steam having a low pressure and temperature in order to suppress the temperature drop of the main turbine casing and nozzles when the port is anchored. I'm leaning. As the warming-up steam main turbine, for example, 10 kg / cm ^2, have been used 260 ° C. of about steam, casing temperature of the main turbine by the warm-up steam to the warm-up state of about 140 ° C. to 100 ° C. It is kept.

  Thus, when leaving the harbor from a berthing state where the main turbine is warmed up, the casing temperature of the main turbine is kept relatively low at about 140 ° C. to 100 ° C., and steam is flowing in the main steam line. Since there is no steam pipe temperature, manual spinning is performed to increase the temperature of the main turbine and the main steam line before leaving the port, but this spinning warm-up takes about 1-2 hours. I need it.

As a conventional technique related to this type of turbine, in order to suppress the increase in turbine speed and the deformation of the turbine casing that occur during the constant turbine speed control during the warm-up operation, the main steam is controlled during the warm-up operation during the start-up process. When the turbine inflow steam amount changes from the state in which the valve opening is maintained and the turbine speed increases, the holding speed of the main steam control valve is corrected to suppress the increase in turbine speed. There is a control method (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 10-238311 (second page, FIG. 4)

  However, as described above, even if manual spinning is performed for 1 to 2 hours in a berthed state, depending on the port, it may not be possible to warm up sufficiently for a long time due to the departure time and the like. Further, manual spinning for 1 to 2 hours may not allow sufficient warm-up.

Therefore, when the main turbine casing in such manual spinning is not to warm enough, the steam during normal operation, for example, because it is 60kg / cm ^2, 500 ℃ about the high-pressure high-temperature steam, the main turbine casing The temperature difference between the inside and outside is large, and sometimes abnormal vibrations are generated during acceleration. This occurs because the main steam during normal operation is at high pressure and high temperature, and is thus rapidly supplied to the main turbine in a warm-up state.

  Further, since such high-pressure and high-temperature steam is supplied, vibration may occur due to a difference in the degree of distortion between the main turbine casing and the rotor. Such abnormal vibration may cause damage to the turbine rotor, the bearing, and the casing.

  Furthermore, troubles such as steam leakage from the joint portion may occur in the main steam line due to large expansion and contraction due to temperature change. In addition, since the main steam line is not warmed, drainage is generated, and this drain flows into the main turbine, causing sudden large vibrations in the main turbine immediately after leaving the port, which may cause a trip.

  In addition, the operation of the main turbine at the time of speed increase at the time of departure from the port is the actual situation that the operation of the port maneuvering is carried out with utmost care while relying on the operator's intuition. It is difficult to increase the speed stably without causing it.

  The steam turbine control method described in the above publication relates to control during warm-up operation for an onshore turbine, and also relates to a control method for maintaining the main turbine speed while keeping the steering valve opening of the main turbine constant. As in the invention of the present application, it is not possible to solve the problem when the steam turbine ship shifts from the warm-up operation during berthing to the normal operation when leaving the port.

  Therefore, in order to solve the above problem, the main turbine speed increasing method for the steam turbine ship according to the present invention is based on the output of the main turbine when the temperature difference between the inside and outside of the main turbine casing is larger than the set temperature difference. A time schedule is created in which the acceleration time is lengthened and the acceleration time with respect to the output of the main turbine is shortened as the temperature difference decreases, and the time according to the actually measured temperature difference between the inside and outside of the main turbine casing. A schedule is selected to control the output and speedup time of the main turbine.

  In addition, the time schedule may be set so that the acceleration time for the increase in output is shortened in the navigation mode of the main turbine, the acceleration time for the increase in output is increased in the navigation mode, and the time schedule is changed by switching the mode of the main turbine. Good.

  Further, in the main turbine speed increasing method of these steam turbine ships, the steam supply amount to the main turbine is limited to a constant amount until the extension amount of the main turbine casing reaches a predetermined value, and the extension amount is a predetermined value. If it exceeds, the maximum supply amount may be gradually increased.

  Further, the main steam temperature is kept at a predetermined low temperature in the ship maneuvering mode until the temperature of the main turbine casing reaches a predetermined value, and when the ship maneuvering mode is switched to the navigation mode, the main steam temperature is changed to the rated main steam at a predetermined time. The main steam temperature may be controlled by gradually increasing the temperature.

Further, in this steam turbine ship main turbine speed-up method, if the low main steam temperature in the ship maneuvering mode is limited to 70% to 90% of the rated main steam temperature in the Celsius temperature scale , stable vibration prevention and temperature rise are achieved. Can be planned.

  On the other hand, when the temperature difference between the inside and outside of the main turbine casing is larger than the set temperature difference, the main turbine speed increasing device for the steam turbine ship according to the present invention increases the speed increasing time with respect to the output of the main turbine, A recording device that records a time schedule in which the acceleration time relative to the output of the main turbine is shortened as the temperature difference decreases, a temperature detector that detects the temperature difference between the inside and the outside of the actual main turbine casing, The time schedule recorded in the recording device is selected according to the temperature difference between the inside and outside of the main turbine casing detected by the temperature detector, and the main turbine output and the acceleration time are determined by the amount of main steam supplied to the main turbine. And a control device for controlling.

  Further, in the main turbine speed increasing device of the steam turbine ship, an extension detector for detecting the extension amount of the main turbine casing is provided, and the extension to the main turbine is increased as the extension amount detected by the extension detector increases. You may make it provide the control apparatus which controls so that the steam supply amount of this may be increased.

  Furthermore, a temperature detector for detecting the temperature of the main turbine casing is provided, and in the ship maneuvering mode, the main steam temperature is kept at a predetermined low temperature until the main turbine casing temperature detected by the temperature detector reaches a predetermined value, When switching from the mode to the navigation mode, a controller may be provided that controls the main steam temperature to gradually rise to the rated main steam temperature in a predetermined time.

  According to the present invention, by means such as described above, stable acceleration can be achieved by suppressing vibration and the like at the time of speed increase when leaving the port from a berthing state in a steam turbine ship.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a main turbine speed increasing device in a steam turbine ship showing a first embodiment of the present invention. FIG. 2 is a partially enlarged cross-sectional view of the main turbine shown in FIG. It is a block diagram which shows the function of the control apparatus shown in FIG. FIG. 4 is a graph showing an example of a time schedule showing the relationship between the temperature difference between the inside and outside of the main turbine casing in the speed increasing device shown in FIG. 1 and the speed increasing time with respect to the output of the main turbine, and FIG. 2 is a graph showing the relationship between the elongation of the main turbine casing and the amount of steam supplied in the speed increasing device shown in FIG. As shown in FIG. 5, in this embodiment, the steam supply amount is represented by the amount of the main turbine control valve lift limit. In this embodiment, an example will be described in which acceleration control based on a time schedule and acceleration control for changing the steam supply amount are performed simultaneously.

  As shown in FIG. 1, in this embodiment, a speed reducer 2 that drives a propeller 1 is provided with a high-pressure main turbine 3 and a low-pressure turbine 4. In this embodiment, the heat recovery efficiency is increased by the low-pressure turbine 4, but the low-pressure turbine 4 may be omitted. In the following description, the speed increase control of the main turbine 3 will be described.

  The main turbine 3 is provided with an inner temperature detector 6 that measures the inner temperature of the main turbine casing 5 and an outer temperature detector 7 that measures the outer temperature. As shown in FIG. 2, the inner temperature detector 6 and the outer temperature detector 7 are provided so as to detect the inner and outer temperatures of the main turbine casing 5 in the plate thickness direction. In this embodiment, as shown in FIG. 1, the inner temperature detector 6 and the outer temperature detector 7 are provided almost in the middle of the main turbine casing 5. The temperatures detected by the inner temperature detector 6 and the outer temperature detector 7 are input to the control device 10 via the wires 8 and 9. An elongation detector 11 for detecting the amount of elongation of the main turbine casing 5 is provided on the axially downstream side of the main turbine casing 5. The casing extension detected by the extension detector 11 is input to the control device 10 via the wiring 12. Furthermore, in this embodiment, a rotor position meter 13 for detecting the elongation of the rotor shaft of the main turbine 3 is provided. The displacement of the rotor shaft detected by the rotor position meter 13 is input to the control device 10 via the wiring 14. A control signal is output from the control device 10 to the control valve 16 that limits the amount of steam supplied to the main turbine 3 via the wiring 15.

  On the other hand, a signal from an engine telegraph 17 provided on the bridge is input to the control device 10. As a signal input from the engine telegraph 17, a signal indicating whether the operation lever 18 is positioned in the navigation mode m (maneuvering zone) or the navigation mode n (navigation zone) is input.

  Further, the control device 10 is connected to a controller 21 of the main boiler 20 by a wiring 19. A signal from a thermometer 23 provided in a supply path 22 for supplying steam from the main boiler 20 to the control valve 16 of the main turbine 3 is input to the controller 21. The illustrated main boiler 20 includes a superheater 24 and a bypass path 25 that adjusts the degree of superheat. The main boiler 20 is connected to the bypass path 25 by a control signal output from the controller 21 based on a signal from the thermometer 23. The amount of steam to be supplied is controlled by the regulating valve 26. Thereby, the temperature of the steam supplied from the superheater 24 of the main boiler 20 to the main turbine 3 is controlled.

  As shown in FIG. 3, the control device 10 includes a temperature difference detection means 30 for obtaining a temperature difference from temperatures inputted from the inner temperature detector 6 and the outer temperature detector 7 and outputting a control signal. From the amount of extension of the main turbine casing 5 input from the extension detector 11 and the amount of displacement of the rotor shaft input from the rotor position meter 13, the respective extension amounts and displacement amounts are obtained and control signals are obtained. An elongation amount detecting means 31 for outputting is provided. In this embodiment, the control signal output from the differential temperature detection means 30 is input to the time schedule setting means 32, and the control signal output from the elongation amount detection means 31 is input to the control valve lift setting means 33. Yes. (A) to (F) shown in the figure are described corresponding to FIG.

  As shown in FIG. 4, as the time schedule set by the time schedule setting means 32, for example, when the normal acceleration time schedule a is set to 1 hour, the temperature obtained by the differential temperature detection means 30 When the difference is 90 ° C, the acceleration time schedule b is inclined so as to be 2 hours, and when the temperature difference reaches 120 ° C, the acceleration time schedule c is inclined so that the acceleration time schedule c is 3 hours. A program is created. That is, when the temperature difference is large, it is determined that the main turbine casing 5 is cold, and the acceleration time is lengthened. In this example, the set temperature difference is set to 90 ° C. and 120 ° C., but these may be determined according to the specifications of the main turbine, etc., and are set in advance and recorded in the time schedule setting means 32.

  These acceleration time schedules a, b, and c are set to have different inclinations depending on whether the engine telegraph 17 is in the ship maneuvering mode m or the navigation mode n, and the normal acceleration time schedule a As in the case of the slope, the acceleration time for increasing the output is shortened in the ship maneuvering mode, and the acceleration time for increasing the output is increased in the navigation mode. The reason why the angle of inclination is varied in this manner is that the ship maneuvering mode m is mainly sailing in the harbor, so that it is necessary to make the rotation speed follow faster with a significantly shorter time program than in the navigation mode n. This is because in the navigation mode n, it is not necessary to follow the rotation speed so fast.

  As shown in FIG. 5, the control valve lift limit by the control valve lift setting means 33 is, for example, constant at 50% opening until the extension amount of the main turbine casing 5 reaches 2 mm, and reaches 2 mm. From 6 to 6 mm, the opening is gradually increased, and when the elongation reaches 6 mm, the opening is fully opened. That is, if the amount of elongation is small, it is determined that the main turbine casing 5 is cold, and the opening of the control valve 16 is reduced. The relationship between the amount of extension of the main turbine casing 5 and the lift limit of the control valve 16 may be set according to the size of the main turbine 3, usage conditions, and the like. As shown in FIG. 1, the opening degree of the control valve 16 is adjusted based on the signal output from the control valve lift setting means 33, and the amount of steam supplied to the main turbine 3 is limited.

  Furthermore, in this embodiment, even when the displacement of the rotor shaft input from the rotor position meter 13 to the extension amount detection means 31 exceeds a predetermined displacement amount, a control signal is output to the control valve lift setting means 33. It is configured as follows. Since the main turbine casing 5 may be deformed abnormally when the displacement of the rotor shaft detected by the rotor position meter 13 is large, the control valve lift setting means is also used when the displacement detected by the rotor position meter 13 is large. A signal for limiting the opening of the control valve 16 is output to 33.

  According to the main turbine speed increasing device 35 configured as described above, first, the inner and outer temperatures of the main turbine casing 5 are measured by the inner temperature detector 6 and the outer temperature detector 7, and the temperature difference is different. The temperature detection means 30 outputs a control signal as a control signal to the time schedule setting means 32, and a predetermined time schedule is selected by the time schedule setting means 32, and the increase (acceleration) of the main turbine output is controlled by the time schedule. As shown in FIG. 4, when the temperature difference detected by the temperature difference detecting means 30 reaches the set temperature of another time schedule, the time schedule is gradually shortened as shown in FIG. The time schedule is switched to Thus, if the temperature difference between the inside and outside of the main turbine casing 5 is larger than a certain set temperature difference, the acceleration time for the output increase is lengthened, and the output suddenly increases when the main turbine casing 5 is cooled. Is suppressed.

  At this time, a control signal is also output from the extension amount detecting means 31 to the control valve lift setting means 33 based on a signal from the casing extension detector 11, and the control valve lift setting is set according to the control signal. The lift amount of the control valve 16 is controlled by the means 33. As shown in FIG. 5, the control of the control valve 16 is performed by stopping the opening of the control valve 16 until the extension amount of the main turbine casing 5 reaches a predetermined value, and when the extension amount reaches the predetermined value, the control valve 16 Control is performed such that the opening degree of the steering valve 16 is gradually increased and the opening degree of the control valve 16 is fully opened when the elongation reaches a predetermined value.

  Furthermore, in this embodiment, the opening degree of the control valve 16 is adjusted not only by the amount of extension of the main turbine casing 5 but also by the displacement of the rotor shaft detected by the rotor position meter 13. This control by the displacement of the rotor shaft reduces abnormal deformation of the main turbine casing 5 by adjusting the opening of the control valve 16 and limiting the steam supply amount when the displacement of the rotor shaft exceeds a predetermined set value. When the set value is exceeded, the steam supply amount is gradually increased to prevent vibration of the main turbine 3.

  In other words, according to the first embodiment, a change in temperature difference between the inside and outside of the main turbine casing 5, the amount of extension of the main turbine casing 5, and the displacement of the rotor shaft are monitored, and vibration occurs when the main turbine speed increases. This is prevented in advance.

  Therefore, according to such a main turbine speed increasing device 35, it is possible to reduce the occurrence of abnormal vibration during the speed increase when leaving the port from a berthing state, steam leakage from the main steam line, and the like. Only a start confirmation operation of the turbine 3 enables a quick departure.

  In the first embodiment, the displacement of the rotor shaft is also monitored. However, even when the displacement of the rotor shaft is not monitored, the main turbine 3 speed increase control can be stably performed.

  Further, in the first embodiment, control for changing the acceleration time schedule according to the temperature difference between the inside and outside of the main turbine casing 5 and the lift amount of the control valve 16 according to the extension amount of the main turbine casing 5 are performed. However, in the ship maneuvering mode, the temperature of the main turbine casing 5 is low and the amount of steam is small. Since the casing temperature is stabilized, the structure may be deformed with a large change.

  FIG. 6 is a graph showing the relationship between the engine telegraph mode and the steam temperature showing the control of the main turbine speed increasing device in the steam turbine ship according to the second embodiment of the present invention. In the second embodiment, vibration is prevented by controlling the temperature of the main steam supplied to the main turbine. Since the configuration is the same as the configuration diagram of the main turbine speed increasing device shown in FIG. 1 described above, the same reference numerals are given to the same configurations as those in the first embodiment described above, and detailed description thereof will be omitted.

  As shown in FIG. 1 described above, the temperature of the main turbine casing 5 detected by the inner temperature detector 6 and the outer temperature detector 7 provided in the main turbine casing 5 and input to the control device 10 is 10 to the controller 21 of the main boiler 20. As the temperature of the main turbine casing 5, the temperature detected by the inner temperature detector 6 or the average value of the temperature detected by the inner temperature detector 6 and the temperature detected by the outer temperature detector 7 is used. This temperature may be determined according to the main steam temperature, a set temperature for adjusting the main steam temperature, or the like. A signal indicating whether the ship maneuvering mode m or the navigation mode n is input from the engine telegraph 17 to the control device 10 is also output to the controller 21 of the main boiler 20. Further, the main steam temperature supplied from the main boiler 20 to the main turbine 3 is input to the controller 21 by a thermometer 23 provided in the supply path 22. The controller 21 is configured to adjust the amount of steam supplied to the superheater 24 of the main boiler 20 with the adjustment valve 26 to adjust the degree of superheat of the steam and adjust the main steam temperature.

  In the controller 21, as shown in FIG. 6, the main steam temperature is maintained at a predetermined low temperature in the boat maneuvering mode m until the temperature of the main turbine casing 5 reaches a predetermined value. When switched to n, the main steam temperature is controlled to gradually rise to the rated main steam temperature in a predetermined time. This control is performed by adjusting the amount of steam by controlling the opening degree of the regulating valve 26. The adjustment of the main steam temperature is not performed when the main turbine casing 5 reaches a predetermined temperature, and is always the rated main steam temperature. In this embodiment, the main steam temperature is adjusted by adjusting the amount of steam, but the main steam temperature may be adjusted by other methods.

The predetermined value of the temperature of the main turbine casing 5 that keeps the main steam temperature at a predetermined low temperature is set to a temperature at which the casing does not greatly deform by the main steam, and is set to about 350 ° C., for example. The main steam temperature until the temperature of the main turbine casing 5 reaches the predetermined value is set to a temperature of about 70 to 90% of the rated main steam temperature. For example, the rated main steam is 60 kg / cm. ^2. If it is about 500 degreeC, it will be set to 350-450 degreeC.

  According to the method of adjusting the main steam temperature according to the temperature of the main turbine casing 5 according to the temperature of the main turbine casing 5 as in the main turbine speed increasing device of the second embodiment, the temperature of the main turbine casing 5 is It is possible to prevent the main turbine from being deformed by supplying high-temperature and high-pressure main steam when the main turbine temperature at the time of departure is low, as the main steam temperature is low at the time of the low maneuvering mode m, and to prevent the occurrence of vibrations. .

  Note that the speed increase control can be performed by combining the first embodiment and the second embodiment described above in combination.

  The above-described embodiment shows an example of the best embodiment, and various modifications can be made without departing from the gist of the present invention, and the present invention is not limited to the above-described embodiment. .

  The main turbine speed increasing method and speed increasing device for a steam turbine ship according to the invention of the present application can suppress the vibration of the main turbine at the time of speed increase when leaving the port from a berthing state, and can stably leave the port. Useful in.

It is a block diagram of the main turbine speed increasing apparatus in the steam turbine ship which shows 1st Embodiment of this invention. It is the partially expanded sectional view which cut | disconnected the casing of the main turbine shown in FIG. It is a block diagram which shows the function of the control apparatus shown in FIG. It is a graph which shows an example of the time schedule which shows the temperature difference between the inner side and the outer side of the main turbine casing in the speed increasing apparatus shown in FIG. 1, and the speed increasing time with respect to the output of the main turbine. It is a graph which shows the relationship between the elongation of the main turbine casing in the speed increasing apparatus shown in FIG. It is a graph which shows the relationship between the engine telegraph mode and steam temperature which show control of the main turbine speed increasing apparatus in the steam turbine ship which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Propeller 2 ... Reduction gear 3 ... Main turbine 4 ... Low pressure turbine 5 ... Main turbine casing 6 ... Inner temperature detector 7 ... Outer temperature detector 8, 9 ... Wiring 10 ... Control device 11 ... Detector 12 ... Wiring 13 ... Rotor position meters 14, 15 ... wiring 16 ... control valve 17 ... engine telegraph 18 ... control lever 19 ... wiring 20 ... main boiler 21 ... controller 22 ... supply path 23 ... thermometer 24 ... superheater 25 ... bypass path 26 ... adjustment Valve 30 ... Differential temperature detection means 31 ... Elongation amount detection means 32 ... Time schedule setting means 33 ... Steering valve lift setting means 35 ... Main turbine speed increasing device ac ... Speed increase time schedule m ... Ship maneuvering mode n ... Navigation mode

Claims (8)

  If the temperature difference between the inside and outside of the main turbine casing is larger than the set temperature difference, the acceleration time for the main turbine output is lengthened, and the acceleration time for the main turbine output increases as the temperature difference decreases. The main time of the steam turbine ship which created a shortened time schedule and selected the time schedule according to the measured temperature difference between the inside and outside of the main turbine casing to control the output and speedup time of the main turbine. Turbine speed increasing method.   2. The time schedule according to claim 1, wherein the time schedule for increasing the output is shortened in the navigation mode of the main turbine, the acceleration time for increasing the output is increased in the navigation mode, and the time schedule is changed by switching the mode of the main turbine. The main turbine speed-up method of the described steam turbine ship. In the steam turbine ship main turbine speed increasing method according to claim 1 or 2,
The steam supply amount to the main turbine is limited to a constant amount until the elongation amount of the main turbine casing reaches a predetermined value, and when the elongation amount exceeds the predetermined value, the steam is gradually increased to the maximum supply amount. Turbine ship main turbine speed increasing method.   The main steam temperature is kept at a predetermined low temperature in the ship maneuvering mode until the temperature of the main turbine casing reaches a predetermined value, and when the ship maneuvering mode is switched to the navigation mode, the main steam temperature is reduced to the rated main steam temperature in a predetermined time. A method for increasing the main turbine speed of a steam turbine ship that is gradually increased. In the steam turbine ship main turbine speed increasing method according to claim 4,
A main turbine speed increasing method for a steam turbine ship in which a low main steam temperature in the boat maneuvering mode is limited to 70% to 90% of a rated main steam temperature on a Celsius temperature scale .   If the temperature difference between the inside and outside of the main turbine casing is larger than the set temperature difference, the acceleration time for the main turbine output is lengthened, and the acceleration time for the main turbine output increases as the temperature difference decreases. A recording device that records the shortened time schedule, a temperature detector that detects a temperature difference between the inside and outside of the actual main turbine casing, and a temperature difference between the inside and outside of the main turbine casing that is detected by the temperature detector. Accordingly, a main turbine speed increasing device for a steam turbine ship provided with a control device that selects a time schedule recorded in the recording device and controls the main turbine output and speed increasing time by the amount of main steam supplied to the main turbine. . In the main turbine speed increasing device of the steam turbine ship according to claim 6,
A control device is provided that includes an elongation detector that detects an elongation amount of the main turbine casing, and controls to increase the amount of steam supplied to the main turbine as the elongation amount detected by the elongation detector increases. The main turbine speed increasing device of the provided steam turbine ship. A temperature detector for detecting the temperature of the main turbine casing is provided, and the main steam temperature is maintained at a predetermined low temperature in the ship operating mode until the main turbine casing temperature detected by the temperature detector reaches a predetermined value. A main turbine speed increasing device for a steam turbine ship provided with a controller for controlling the main steam temperature to gradually rise to a rated main steam temperature in a predetermined time when switching to a navigation mode.

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