JP2017096194A - External turbine chamber supporting structure for steam turbine, external turbine chamber for steam turbine, steam turbine and process of manufacture of steam turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an external turbine chamber supporting structure for a steam turbine having a convenient configuration and capable of sufficiently improving a performance of the steam turbine.SOLUTION: An external turbine chamber supporting structure 9 for a steam turbine 3 is the external turbine chamber supporting structure 9 for a steam turbine 3 for supporting a lower half part 63 of an external turbine chamber 60 of the steam turbine 3 at a frame table 8 enclosing the lower half part 63, there are provided an engaging part 91 arranged at one of an outer surface of the lower half part 63 and an inner surface of the frame table 8 opposing to each other and having a hole part opened upwardly and a slit for communicating the hole part toward to the other one over a vertical direction and an engaging part 92 having an inserted and passed part arranged at the other of the outer surface of the lower half part 63 and the inner surface of the frame table 8 and inserted into or passed through the slit and a flange part arranged at an end part of one side of the inserted and passed part and protruded out of the outer surface of the inserted or passed part in the hole part.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an external casing support structure for a steam turbine, an external casing for a steam turbine, a steam turbine, and a method for manufacturing the steam turbine.

  The steam turbine plant includes a plurality of steam turbines used as a high-pressure steam turbine, an intermediate-pressure steam turbine, and a low-pressure steam turbine, respectively. The steam turbine includes a rotor that is rotationally driven by high-pressure steam, an internal compartment that houses the rotor, and an external compartment that houses the internal compartment. The high-pressure steam is first introduced into the high-pressure steam turbine to drive the high-pressure steam turbine, and then sequentially introduced into the intermediate-pressure steam turbine and the low-pressure steam turbine to drive these steam turbines.

  In the low-pressure steam turbine, the steam used for the rotational drive of the rotor is exhausted into the outer casing kept in a vacuum through the inner casing. On the other hand, since the outside of the external compartment is atmospheric pressure, pressure is applied to the external compartment from the outside by the atmospheric pressure. In order to resist such pressure, the inside of the external compartment is reinforced by a support structure called a stay bar as an example.

  On the other hand, when a large number of the above-mentioned stay bars are provided, there is a possibility that the flow of exhaust gas flowing through the external vehicle compartment is hindered by these stay bars. If the flow of exhaust is obstructed, there is a concern that it will affect the performance of the steam turbine.

  Therefore, in addition to the stay bar, an example in which an external casing (low pressure casing) of a low pressure steam turbine as in Patent Document 1 below is applied is known. The low-pressure casing described in Patent Document 1 is fixed integrally with the foundation frame via a rod pull. Thereby, it is supposed that the durability of the low pressure casing is improved.

JP 59-38402 A

  However, since the technique described in Patent Document 1 requires a large-scale construction, there is a possibility of hindering cost reduction and delivery time reduction. Furthermore, in recent years, the demand for improving the performance of existing steam turbines is particularly increasing.

  The present invention has been made in order to solve the above-described problems, and has a simple configuration and can sufficiently improve the performance of the steam turbine. An object is to provide an external casing of a turbine, a steam turbine, and a method of manufacturing the steam turbine.

  According to the first aspect of the present invention, the outer casing support structure of the steam turbine is configured to support the outer casing of the steam turbine that supports the lower half of the outer casing of the steam turbine on the frame surrounding the lower half. A hole provided on one of the outer surface of the lower half and the inner surface of the gantry opposite to each other, and a slit that opens upward, and a slit that communicates the hole toward the other side in the vertical direction. An engaging portion, an insertion portion that is provided on the other of the outer surface of the lower half portion and the inner surface of the mount, and is provided at an end portion on the one side of the insertion portion. A locking portion having a flange portion protruding from the outer surface of the insertion portion in the hole portion.

When pressure is applied to the external casing from the outside, force is applied between the external casing and the gantry in a direction away from each other. However, according to the above configuration, the engaging portion provided on one of the outer surface of the lower half of the outer casing and the inner surface of the gantry, and the other of the outer surface of the lower half of the outer casing and the inner surface of the gantry The engaging portions provided on the two engage with each other. Specifically, by engaging the flange portion inside the slit, the engaging portion and the locking portion are engaged. Thereby, it is possible to sufficiently resist the force acting between the external compartment and the gantry. That is, the structural strength of the external compartment can be increased by pulling the external compartment from the outside.
Furthermore, with the above configuration, the number of other reinforcing structures provided inside the external compartment can be reduced. Thereby, possibility that the flow of the fluid which distribute | circulates the inside of an external compartment will be inhibited can be reduced.

  According to a second aspect of the present invention, in the outer casing support structure for a steam turbine according to the first aspect, the engagement portion is formed by an outer surface of the lower half portion and an inner surface of the gantry facing each other. A pair of bracket main bodies provided on one side and extending toward the other side; and a pair of slit forming portions provided on respective end edges on the other side of the pair of bracket main bodies and extending in directions facing each other. The slit is formed between the pair of slit forming portions, and the locking portion is an anchor bolt having a rod-shaped shaft portion and a flange-shaped head, and the shaft The portion may constitute the insertion portion, and the head portion may constitute the flange portion.

  According to this configuration, the slit forming portion and the head portion of the anchor bolt are engaged with each other from the direction in which the shaft portion extends. As a result, the external compartment can be stably supported by the gantry. Furthermore, since the engaging portion is formed only by the bracket main body and the slit forming portion and the locking portion is formed by the anchor bolt, the structure of the device can be suppressed simply and inexpensively.

  According to a third aspect of the present invention, in the outer casing support structure for a steam turbine according to the first aspect, the engaging portion is a concave groove extending in the vertical direction and having the slit, The stop portion may include a support plate portion serving as the insertion portion extending in the vertical direction and a locking plate portion serving as the flange portion provided at an end portion of the support plate portion.

  According to this configuration, the slit of the concave groove and the locking plate portion are engaged with each other from the extending direction of the support plate portion. As a result, the external compartment can be stably supported by the gantry. Furthermore, since the concave groove and the locking plate portion extend in the vertical direction, the outer casing can be supported more stably by the gantry, and can be locally applied to the locking portion and the engaging portion. The possibility that a typical load is applied can be reduced.

  According to the fourth aspect of the present invention, the external casing support structure of the steam turbine according to any one of the first to third aspects is interposed between the flange part and the engagement part, The insertion portion has a spacer that passes through, and the spacer may be formed with an insertion hole through which the insertion portion is inserted, and a communication hole that connects the insertion hole and the outer peripheral edge of the spacer. .

  According to this configuration, by interposing a spacer between the flange portion and the engaging portion, even when a gap is generated between the flange portion and the engaging portion, the gap is filled. Can do. That is, it is possible to absorb a dimensional error between the flange portion and the engaging portion and to stably support the outer casing by the gantry.

  According to the fifth aspect of the present invention, the external casing support structure for the steam turbine according to any one of the first to fourth aspects is provided inside the engagement portion and moves the flange portion. You may have a filling part fixed impossible.

  According to this structure, a flange part can be fixed immovably with respect to an engaging part by providing a filling part. As a result, the external compartment can be stably supported by the gantry.

  According to a sixth aspect of the present invention, in the outer casing support structure for a steam turbine according to any one of the first to fifth aspects, the engaging portion is provided in the lower half portion, and The stop may be provided on the inner surface of the gantry.

  According to this configuration, since the engaging portion provided in the lower half portion of the external casing and the locking portion provided on the inner surface of the gantry are engaged with each other, the outer cab is stably supported by the gantry. can do.

  According to a seventh aspect of the present invention, in the outer casing support structure for a steam turbine according to any one of the first to fifth aspects, the engaging portion is provided on the inner surface of the gantry, The locking part may be provided in the lower half part.

  According to this configuration, the engaging portion provided on the inner surface of the gantry and the engaging portion provided in the lower half of the outer casing are engaged with each other, so that the outer casing is stably supported by the gantry. can do.

  According to the eighth aspect of the present invention, the external casing of the steam turbine is any one of the external casing main body that houses the internal casing and the steam first to seventh provided in the external casing main body. An external casing support structure for the steam turbine according to the aspect.

  According to this structure, the outer casing of the steam turbine that can be stably supported by the gantry can be provided.

  According to the ninth aspect of the present invention, the steam turbine includes a rotor that is rotationally driven by steam, an internal casing that houses the rotor, and an external vehicle according to the eighth aspect that stores the internal casing. A chamber.

  According to this structure, a steam turbine provided with the outer casing of the steam turbine which can be stably supported by the gantry can be provided. In particular, in such a steam turbine, the outer casing is reinforced from the outside by a gantry, and therefore the number of other reinforcing structures provided inside the outer casing can be reduced. Thereby, since possibility that the flow of the fluid which distribute | circulates an external vehicle interior part will be prevented is reduced, the performance of a steam turbine can further be improved.

  According to a tenth aspect of the present invention, a method for manufacturing a steam turbine is a method for manufacturing a steam turbine including the outer casing support structure for a steam turbine according to any one of the first to seventh aspects, Providing the engaging portion on one of the outer surface of the lower half and the inner surface of the gantry facing each other, and providing the locking portion on the other of the outer surface of the lower half and the inner surface of the gantry; And lowering the lower half portion from above to the inside of the pedestal, thereby inserting the insertion portion into the slit and engaging the flange portion with the engagement portion.

  According to this method, the engaging portion and the engaging portion can be engaged with each other at the same time as the lower half is lowered from the upper side toward the gantry. Thereby, a man-hour and cost can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, while having a simple structure, the external casing support structure of a steam turbine which can fully improve the performance of a steam turbine, the external casing of a steam turbine provided with the same, a steam turbine, and steam A method for manufacturing a turbine can be provided.

It is a figure showing composition of steam turbine equipment concerning an embodiment of the present invention. It is a perspective view which shows the structure of the steam turbine (low pressure steam turbine) which concerns on 1st embodiment of this invention, and an external compartment support structure. It is sectional drawing in the III-III line of FIG. It is an enlarged view which shows the structure of the external compartment support structure which concerns on 1st embodiment of this invention. It is a figure which shows the spacer which concerns on 1st embodiment of this invention. It is process drawing which shows the manufacturing method of the steam turbine which concerns on 1st embodiment of this invention. It is a perspective view which shows the structure of the steam turbine (low pressure steam turbine) which concerns on 2nd embodiment of this invention, and an external compartment support structure. It is an enlarged view which shows the structure of the external compartment support structure which concerns on 2nd embodiment of this invention. It is an enlarged view which shows the modification of the external compartment support structure which concerns on 2nd embodiment of this invention.

[First embodiment]
A first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the steam turbine equipment 100 according to the present embodiment includes a high-pressure steam turbine 1, an intermediate-pressure steam turbine 2, a low-pressure steam turbine 3, a boiler 4 that supplies high-pressure steam to the high-pressure steam turbine 1, A reheater 5 that reheats the steam discharged from the high pressure steam turbine 1 and supplies the steam to the intermediate pressure steam turbine 2, and a condenser 6 that recovers exhaust gas (steam) from the low pressure steam turbine 3 and returns it to water. And a generator 7 driven by the rotational driving force of the steam turbine 3.

  The high-pressure steam turbine 1 includes a high-pressure turbine rotor 11 that is rotationally driven by steam supplied from the boiler 4, and a high-pressure turbine casing 12 that covers the high-pressure turbine rotor 11 from the outside. The high-pressure turbine rotor 11 is provided with a plurality of moving blade rows 11A. Inside the high-pressure turbine casing 12, there are provided a plurality of stationary blade rows 11B arranged alternately in the steam flow direction with respect to the moving blade rows 11A.

  Similarly, the intermediate pressure steam turbine 2 is recovered from the high pressure steam turbine 1 and rotated by the steam heated by the reheater 5, and the intermediate pressure turbine rotor 21 covers the intermediate pressure turbine rotor 21 from the outside. And a pressure turbine casing 22. The intermediate pressure turbine rotor 21 is provided with a plurality of moving blade rows 21A. Inside the intermediate pressure turbine casing 22, a plurality of stationary blade rows 21 </ b> B are alternately arranged in the direction in which steam flows with respect to the moving blade rows 21 </ b> A.

  Furthermore, the low-pressure steam turbine 3 includes a low-pressure turbine rotor 31 that is rotationally driven by the steam recovered from the intermediate-pressure steam turbine 2 and a low-pressure turbine casing 32 that covers the low-pressure turbine rotor 31 from the outside. The low-pressure turbine rotor 31 is also provided with a plurality of moving blade rows 31A. Inside the low-pressure turbine casing 32, a plurality of stationary blade rows 31B are alternately arranged in the direction in which steam flows with respect to the moving blade rows 31A. In the present embodiment, the low pressure steam turbine 3 may be simply referred to as the steam turbine 3.

  The high-pressure turbine rotor 11, the intermediate-pressure turbine rotor 21, and the low-pressure turbine rotor 31 are connected to each other on the same rotation axis. As a result, the high-pressure turbine rotor 11, the intermediate-pressure turbine rotor 21, and the low-pressure turbine rotor 31 rotate as a single turbine rotor 40. On the other hand, the high-pressure turbine casing 12, the intermediate-pressure turbine casing 22, and the low-pressure turbine casing 32 described above are provided independently.

  A steam flow path connecting the boiler 4 and the high-pressure steam turbine 1 is provided with a main steam valve V1 (MSV) and a regulating valve V2 (GV) arranged in series with the main steam valve V1. . By opening and closing the main steam valve V1, the supply of steam to the high-pressure steam turbine 1 (opening / closing state of the steam flow path) can be switched.

  Next, the configuration of the low-pressure steam turbine 3 (steam turbine 3) will be described in detail with reference to FIGS. As shown in these drawings, the steam turbine 3 includes a low-pressure turbine rotor 31 (rotor 31) that is rotationally driven by steam supplied from the intermediate pressure steam turbine 2, and rotatably supports the rotor 31, and from the outside. An internal casing 50 that forms a flow path on the inside by covering and an external casing 60 that further covers the internal casing 50 from the outside are provided.

  Furthermore, the steam turbine 3 according to the present embodiment is surrounded from the outside by a gantry 8 formed of, for example, reinforced concrete. The gantry 8 is formed with a rectangular support opening 8A penetrating in the vertical direction. As will be described in detail later, the steam turbine 3 is fitted into the support opening 8A from above, and is supported by an external compartment support structure 9 provided between the gantry 8 and the external compartment 60.

  As shown in FIG. 3, the internal casing 50 is a member that has a larger outer dimension than the rotor 31 and has a substantially cylindrical shape. Inside the inner casing 50, the above-described stationary blade row is provided. These stator blade rows are alternately arranged with the rotor blade rows provided on the rotor 31 in a state where the rotor 31 is covered by the inner casing 50. Furthermore, the internal casing 50 is divided into two in the vertical direction. Specifically, the upper half of the internal compartment 50 is an upper half 51 of the internal compartment, and the lower half 52 is an internal compartment lower half 52.

  The external compartment 60 includes an external compartment body 61 that covers the internal compartment 50 from the outside, and an external compartment support structure 9 that is provided between the gantry 8 that surrounds the external compartment body 61 from the outside. .

  The outer casing body 61 has a larger outer dimension and volume than the inner casing 50. The internal compartment 50 is accommodated inside the external compartment body 61. The outer casing body 61 is divided into two in the vertical direction, like the inner casing 50. The upper half of the outer casing 61 is an upper half 62 (upper half) of the outer casing, and the lower half 63 (lower half) of the outer casing is the lower half.

  As shown in FIG. 3, when viewed from the direction in which the rotor 31 extends, the outer casing upper half 62 has a semicircular cross section. The lower edge of the outer casing upper half 62 is fixed to the outer casing lower half 63 through a fixing portion (not shown). The outer casing lower half 63 has a pair of side plates 64 extending in the vertical direction when viewed from the direction in which the rotor 31 extends, and a foot 65 provided at the upper end of the side plates 64.

  The outer surface 66 of the side plate 64 extends substantially in the vertical direction, and faces the inner surface 81 of the support opening 8A in the gantry 8 described above. The foot 65 has a plate-like foot main body 65M extending horizontally from the upper end of the side plate 64, and a plurality of reinforcing plates 67 connecting the upper surface of the foot main body 65M and the side plate 64. ing. The foot main body 65 </ b> M extends substantially parallel to the surface of the gantry 8. Further, the upper surface of the foot main body 65M is fixed to the outer surface 66 of the side plate 64 via a substantially triangular reinforcing plate 67. The upper surface of the gantry 8 supports the foot 65 from below by contacting the lower surface of the foot main body 65M. That is, the weight of the steam turbine 3 is supported on the gantry 8 by the foot 65.

  Further, the condenser 6 described above is connected below the lower half 63 of the external casing. Steam (exhaust gas) flowing through the steam turbine 3 flows into the condenser 6 through the lower half 63 of the external casing.

  Although detailed description is omitted, as shown in FIG. 3, rod-like stay bars 68 for connecting the respective wall surfaces to each other may be provided inside the lower half 63 of the outer casing. Even if pressure is applied to the outer casing lower half 63 from the outside, the pressure can be resisted by reinforcing the outer casing lower half 63 from the inside by the stay bars 68. The number of stay bars 68 may be arbitrarily determined as long as the flow of steam (exhaust gas) flowing through the external compartment 60 is not hindered.

The external casing support structure 9 is provided between the outer surface 66 of the lower half 63 of the outer casing and the inner surface 81 (inner peripheral surface of the support opening 8A) of the gantry 8, so that the outer casing 60 (external casing) is provided. The lower half 63) is supported so as to be pulled from the outside.
More specifically, the outer compartment support structure 9 includes an engaging portion 91 and a locking portion 92 provided on one and the other of the outer surface 66 of the lower half 63 of the outer casing and the inner surface 81 of the mount 8, respectively. And a spacer 93 interposed between the engaging portion 91 and the locking portion 92. In the following description, a direction connecting the engaging portion 91 and the locking portion 92 may be referred to as an engaging direction.

  In the present embodiment, a bracket 91 </ b> B provided on the outer surface 66 of the lower half 63 of the external compartment is employed as the engaging portion 91. Returning to FIG. 2 again, in the present embodiment, the side plate 64 of the lower half 63 of the outer casing is provided with a plurality of brackets 91B arranged at intervals in the vertical and horizontal directions. More specifically, two brackets 91B are arranged in the vertical direction on one side plate 64, and four or three brackets 91B are arranged in the horizontal direction. . That is, a total of eight or six brackets 91B are provided on one side plate 64. Furthermore, since the lower half 63 of the outer casing is substantially rectangular when viewed from above, a total of 28 brackets 91B are provided on the four side plates 64.

  As shown in FIG. 4, each bracket 91B includes a pair of bracket main bodies 91H extending from the outer surface 66 of the side plate 64 toward the other side (the side facing the inner surface 81 of the gantry 8), and the other end of the bracket main body 91H. A pair of slit forming portions 91 </ b> S extending in a direction facing each other.

  Each bracket body 91 </ b> H has a plate shape extending in a direction substantially orthogonal to the outer surface 66 of the lower half 63 of the outer casing when viewed from the vertical direction. Each slit forming portion 91S extends in a direction substantially orthogonal to the bracket body 91H. A constant gap (slit S) is formed between the slit forming portions 91S. The width dimension of the slit S (the dimension between the slit forming portions 91S in the horizontal direction) is appropriately determined according to the dimension of the flange portion 92F of the locking portion 92 described later.

  With the above configuration, a space (hole H) surrounded by the bracket 91B itself and the outer surface 66 (side plate 64) is formed inside the bracket 91B. The upper end and the lower end of the bracket 91B are opened upward and downward, respectively. Further, the slit S communicates the hole H from one side (the outer surface 66 side of the lower half 63 of the external casing) toward the other side (the inner surface 81 side of the gantry 8).

  Next, the locking portion 92 will be described. A plurality of locking portions 92 are provided on the inner surface 81 of the gantry 8 at positions corresponding to the engagement portions 91 (brackets 91B) in plan view. In the present embodiment, an example in which an anchor bolt 92B is used as the locking portion 92 will be described. As shown in FIG. 4, the anchor bolt 92B includes a shaft portion 92S (insertion portion 92S) extending in a rod shape, and a flange-shaped head portion 92F (flange portion 92F) provided at an end portion of the shaft portion 92S. Have. A part of the shaft portion 92 </ b> S is inserted into a buried hole 82 formed in the inner surface 81 of the gantry 8. A filler 83 such as grout is filled between the outer peripheral surface of the shaft portion 92 </ b> S and the inner peripheral surface of the embedded hole 82. Note that the outer diameter of the shaft portion 92S is slightly smaller than the width dimension of the slit S described above.

  A head portion 92F that projects outward from the outer peripheral surface of the shaft portion 92S is integrally provided at one end (outer surface 66 side) of the shaft portion 92S. More specifically, the horizontal dimension of the head portion 92F is sufficiently larger than the width dimension of the slit S. Thereby, in a state where the head portion 92F is positioned in the hole portion H of the slit S, the head portion 92F is locked without deviating from the hole portion H to the outside.

  Further, in the present embodiment, a substantially plate-like spacer 93 is provided between the bracket 91B and the anchor bolt 92B. The spacer 93 is interposed between the slit forming portion 91S and the head portion 92F without a gap. That is, the spacer 93 functions as a positioning member (shim) in the engaging direction between the engaging portion 91 and the locking portion 92.

  Specifically, as shown in FIG. 5, the spacer 93 has a substantially circular shape when viewed from the engagement direction. In a region including the center of the spacer 93, a substantially circular insertion hole 93H through which the shaft portion 92S of the anchor bolt 92B described above is inserted is provided. The inner diameter of the insertion hole 93H is equal to or slightly larger than the outer diameter of the shaft portion 92S. Further, the insertion hole 93H is communicated with a part of the outer peripheral edge 93R of the spacer 93 by the communication hole 93C. By providing the communication hole 93C, when the anchor bolt 92B and the bracket 91B are engaged, when the spacer 93 is sandwiched in the gap between the head 92F and the slit forming portion 91S, the spacer 93 and the anchor Interference with the shaft 92S of the bolt 92B is avoided.

  Then, the manufacturing method of the steam turbine 3 provided with said external compartment support structure 9 is demonstrated with reference to FIG. As shown in the figure, in the method for manufacturing the steam turbine 3, first, the bracket 91B as the engaging portion 91 is attached to the outer surface 66 of the lower half 63 of the outer casing (step S1).

  After the S1 step or in parallel with the S1 step, the anchor bolt 92B as the locking portion 92 is embedded in the inner surface 81 of the gantry 8 (S2 step). Next, the lower half portion 63 of the external compartment with the bracket 91B attached is suspended upward by a crane or the like and then lowered from above toward the support opening 8A of the gantry 8 (step S3).

  In step S3, the lower half 63 of the outer casing is lowered to insert the shaft portion 92S of the anchor bolt 92B into the slit S of the bracket 91B from above, and the head portion 92F of the anchor bolt 92B is attached to the bracket. It is stored inside 91B. Thereby, the bracket 91B and the anchor bolt 92B are engaged with each other. In this S3 step, the above-described spacer 93 may be attached between the slit forming portion 91S and the head 92F of the anchor bolt 92B.

  Further, the lower lower half portion 52 of the internal casing, similarly suspended by a crane or the like, is lowered and installed on the lower half portion 63 of the outer casing (step S4). Subsequently, the turbine rotor 40 (rotor 31) is installed on the lower half 52 of the internal casing (step S5). Prior to the installation of the rotor 31, auxiliary equipment such as a bearing device and a lubrication device may be installed on the lower half 52 of the internal casing.

  Next, the rotor 31 is covered from both sides in the vertical direction by installing the upper half 51 of the inner casing on the lower half 52 of the inner casing (step S6). Subsequently, the outer casing upper half 62 is installed on the outer casing lower half 63 (step S7). Thus, the steps of the method for manufacturing the steam turbine 3 according to the present embodiment are completed.

  In the steam turbine equipment 100 configured as described above, first, high-pressure steam supplied from the boiler 4 to the high-pressure steam turbine 1 sequentially collides with the moving blade row and the stationary blade row, so that the turbine rotor 40 is rotationally driven. Is done. The steam exhausted from the high-pressure steam turbine 1 is heated by the reheater 5 to be heated, and then flows into the intermediate-pressure steam turbine 2.

  In the intermediate pressure steam turbine 2, a rotational driving force is further applied to the rotating turbine rotor 40 by the inflowing steam. The steam exhausted from the intermediate pressure steam turbine 2 flows into the subsequent low pressure steam turbine 3. Even in the low-pressure steam turbine 3, a rotational driving force is further applied to the turbine rotor 40 by the steam.

  The steam exhausted from the low-pressure steam turbine 3 (steam turbine 3) flows toward the condenser 6. In the condenser 6, the vapor is condensed by the refrigerant and returned to the water. At this time, as the water condenses, the pressure in the condenser 6 is reduced to a vacuum state. Accordingly, the low-pressure turbine casing 32 (external casing 60) communicated with the condenser 6 is generally in a vacuum state as with the condenser 6. That is, pressure is applied to the external casing 60 from the outside by atmospheric pressure.

  That is, in the high-pressure steam turbine 1 and the medium-pressure steam turbine 2, the internal pressure becomes higher than the atmospheric pressure due to the high-pressure steam, while in the low-pressure steam turbine 3, the inside is in a negative pressure state with respect to the atmospheric pressure. For this reason, unlike the high-pressure steam turbine 1 and the intermediate-pressure steam turbine 2, the low-pressure steam turbine 3 requires a structure that can resist pressure from the outside.

  As such a structure, it is conceivable to arrange a plurality of the above-described stay bars 68 inside the external compartment 60. However, when a large number of stay bars 68 are provided, there is a concern that the flow of fluid (steam) flowing through the inside of the external casing 60 may be hindered.

  Therefore, in the present embodiment, the above-described pressure is countered by pulling the external casing 60 from the outside by the external casing support structure 9 as described above. That is, according to the above-described configuration, the engaging portion 91 provided on one of the outer surface 66 of the outer casing lower half 63 and the inner surface 81 of the gantry 8, and the outer surface 66 and pedestal of the outer casing lower half 63. 8 and the engaging portion 92 provided on the other side of the inner surface 81 engage with each other. Specifically, when the flange portion 92F is engaged with the inside of the slit S, the engaging portion 91 and the locking portion 92 are engaged. Thereby, it is possible to sufficiently resist the force acting between the external casing 60 and the gantry 8. By pulling the external casing 60 from the outside, the structural strength of the external casing 60 can be increased.

  Furthermore, since the strength of the lower half 63 of the external casing can be increased by the above configuration, the number of other reinforcing structures including the stay bar 68 provided inside the external casing 60 can be reduced. Thereby, possibility that the flow of the vapor | steam which distribute | circulates the inside of the external compartment 60 will be inhibited can be reduced. By improving the flow of steam inside the external casing 60 in the low-pressure steam turbine 3, the exhaust characteristics of the steam turbine 3 are improved. That is, the performance of the steam turbine 3 can be improved.

  In addition, according to the above-described configuration, since the bracket 91B is used as the engaging portion 91 and the anchor bolt 92B is used as the locking portion 92, the slit forming portion 91S of the bracket 91B and the head of the anchor bolt 92B are used. 92F is engaged with each other from the extending direction (engagement direction) of the shaft portion 92S. As a result, the external casing 60 can be stably supported by the gantry 8. Furthermore, since the engaging portion 91 is formed only by the bracket main body 91H and the slit forming portion 91S, and the locking portion 92 is formed by the anchor bolt 92B, the structure of the apparatus can be suppressed simply and inexpensively.

  Further, since the structure is simple as described above, the external casing support structure 9 can be easily applied to the existing steam turbine 3. That is, it is possible to easily improve the performance of the existing steam turbine 3.

  Furthermore, according to the above-described configuration, the spacers 93 are interposed between the head 92F (flange portion 92F) of the anchor bolt 92B and the bracket 91B (slit forming portion 91S), so that the head 92F and the bracket 91B are interposed. Even if a gap occurs between the two, the gap can be filled. That is, it is possible to absorb the dimensional error between the flange portion 92 </ b> F and the engaging portion 91 and to stably support the outer casing 60 by the gantry 8.

  In addition, according to the above-described method for manufacturing the steam turbine 3, the lower half 63 of the outer casing is finished descending from the upper side toward the mount 8, and at the same time, the engaging portion 91 (bracket 91B) and the locking portion 92 ( The anchor bolts 92B) can be engaged with each other. Thereby, a man-hour and cost can be suppressed.

  In the present embodiment, the example in which the engaging portion 91 is provided on the outer surface 66 of the lower half portion 63 of the outer casing and the locking portion 92 is provided on the inner surface 81 of the gantry 8 has been described. However, whether the engaging portion 91 and the engaging portion 92 are provided on the outer surface 66 of the lower half portion 63 of the outer casing or the inner surface 81 of the mount 8 is not limited depending on the present embodiment. That is, contrary to the present embodiment, the engaging portion 91 may be provided on the inner surface 81 of the gantry 8, and the engaging portion 92 may be provided on the outer surface 66 of the outer casing lower half portion 63.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, about the structure similar to 1st embodiment, after attaching the same code | symbol, detailed description is abbreviate | omitted. As shown in FIG.7 and FIG.8, in this embodiment, the structure of the external compartment support structure 19 differs from the above-mentioned first embodiment.

  More specifically, the external compartment support structure 19 according to the present embodiment has a T-section steel 192T as a locking portion 192 provided on the outer surface 66 of the lower half 63 of the external compartment, and an inner surface 81 of the gantry 8. It has the engaging part 191 (concave groove 191R) provided, and the filling part C (refer FIG. 8) provided in the concave groove 191R.

  As shown in FIG. 8, the T-shaped steel 192 </ b> T includes a support plate 192 </ b> S extending in a direction (engagement direction) generally orthogonal to the outer surface 66 of the lower half 63 of the outer casing as seen from the vertical direction. And a locking plate portion 192L provided at an end portion on the other side (the inner surface 81 side of the gantry 8) of the portion 192S. The locking plate portion 192L is substantially orthogonal to the support plate portion 192S when viewed from the up-down direction. In other words, the T-section steel 192T is substantially T-shaped when viewed from the vertical direction. The T-shaped steel 192T extends in the vertical direction on the outer surface 66 of the lower half 63 of the outer casing. A plurality of T-shaped steel 192T as described above is provided in the horizontal direction on one side plate 64 in the lower half 63 of the outer casing. Specifically, in this embodiment, three or four T-section steel 192T are provided on one side plate 64.

  A plurality of concave grooves 191 </ b> R serving as engaging portions 191 are formed on the inner surface 81 of the gantry 8. A plurality of the concave grooves 191R are provided on the inner surface 81 of the gantry 8 at positions corresponding to the locking portions 192 (T-section steel 192T) in plan view. More specifically, the concave groove 191R is a rectangular groove extending in the vertical direction on the inner surface 81 of the gantry 8 formed of reinforced concrete or the like. A first protective steel plate B1 is provided inside the recessed groove 191R. The first protective steel plate B1 has a substantially C shape with one opening as viewed from the top and bottom so as to correspond to the cross-sectional shape of the concave groove 191R.

  Further, a second protective steel plate B2 is provided on the inner surface 81 of the gantry 8 so as to cover only a part of the opening of the concave groove 191R. In the second protective steel plate B2, a slit S2 is formed as shown in FIG. The width dimension of the slit S2 in the horizontal direction is substantially the same as or slightly larger than the thickness dimension of the support plate part 192S in the locking part 192. Further, the slit S2 is formed uniformly in the vertical direction.

  With the configuration as described above, a space (hole H2) surrounded by the first protective steel plate B1 and the second protective steel plate B2 is formed inside the concave groove 191R. The upper end and the lower end of the concave groove 191R open upward and downward, respectively. Further, the slit S2 communicates the hole H2 from one side (the outer surface 66 side of the lower half 63 of the outer casing) toward the other side (the inner surface 81 side of the gantry 8).

  In a state where the outer casing lower half 63 is placed inside the gantry 8, the locking plate 192L of the T-shaped steel 192T is housed inside the concave groove 191R. Thereby, the locking plate portion 192L engages with the inside of the second protective steel plate B2 that forms the slit S. Further, in the present embodiment, a filling portion C that fixes the locking plate portion 192L so as not to move is provided inside the concave groove 191R. The filling portion C is formed by, for example, filling a filling material 83 such as grout inside the concave groove 191R without any gap and then curing the filling material.

  Even with the above-described configuration, as in the first embodiment, the engaging portion 91 provided on one of the outer surface 66 of the lower half 63 of the outer casing and the inner surface 81 of the gantry 8 and the bottom of the outer casing The outer surface 66 of the half portion 63 and the locking portion 92 provided on the other of the inner surface 81 of the gantry 8 are engaged with each other. Specifically, the T-shaped steel 192T (locking plate portion 192L) is engaged with the inner side (second protective steel plate B2) of the concave groove 191R, so that the engaging portion 91 and the locking portion 92 are engaged. Is done. Thereby, it is possible to sufficiently resist the force acting between the external casing 60 and the gantry 8. By pulling the external casing 60 from the outside, the structural strength of the external casing 60 can be increased.

  Furthermore, since the strength of the lower half 63 of the external casing can be increased by the above configuration, the number of other reinforcing structures including the stay bar 68 provided inside the external casing 60 can be reduced. Thereby, possibility that the flow of the vapor | steam which distribute | circulates the inside of the external compartment 60 will be inhibited can be reduced. By improving the flow of steam inside the external casing 60 in the low-pressure steam turbine 3, the exhaust characteristics of the steam turbine 3 are improved. That is, the performance of the steam turbine 3 can be improved.

  In addition, according to the above-described configuration, the slit S2 of the concave groove 191R and the locking plate portion 192L are engaged with each other from the extending direction of the support plate portion 192S. As a result, the external casing 60 can be stably supported by the gantry 8. Further, since the recessed groove 191R and the locking plate portion 192L extend in the vertical direction, the outer casing 60 can be supported more stably by the gantry 8, and the locking portion 192 and the engagement portion 192 can be engaged. The possibility that a local load is applied to the unit 191 can be reduced.

  In addition, according to the above-described configuration, by providing the filling portion C, the flange portion 92F can be fixed to the engaging portion 91 so as not to move. Here, when there is a variation in the size of the gap between the locking plate portion 192L and the first protective steel plate B1 in the concave groove 191R, it is necessary to adjust the positioning member such as a shim according to the size of each gap. There is. However, by providing the filling portion C, the space (hole portion H2) in the concave groove 191R can be uniformly filled without undergoing such dimension adjustment of the shim or the like. That is, man-hours and costs can be reduced.

  In the present embodiment, the example in which the engaging portion 191 is provided on the inner surface 81 of the gantry 8 and the engaging portion 192 is provided on the outer surface 66 of the lower half portion 63 of the external casing has been described. However, whether the engaging portion 191 and the locking portion 192 are provided on the outer surface 66 of the lower half portion 63 of the outer casing or the inner surface 81 of the mount 8 is not limited depending on the present embodiment. That is, contrary to the present embodiment, the engaging portion 191 may be provided on the outer surface 66 of the external casing 60, and the locking portion 192 may be provided on the inner surface 81 of the gantry 8.

[Modification of Second Embodiment]
Next, a modification of the second embodiment of the present invention will be described with reference to FIG. As shown in the figure, the filling portion C is not provided in the present modification. Further, a plate-like spacer 193 that closes the gap is interposed in the gap between the locking plate portion 192L and the first protective steel plate B1. According to such a configuration, the dimensional error between the locking plate portion 192L and the first protective steel plate B1 can be absorbed, and the external casing 60 can be stably supported by the gantry 8.
In addition, it is also possible to provide said filling part C in the state which attached this spacer 193. FIG.

The embodiments of the present invention have been described above with reference to the drawings. However, various changes and modifications can be made to the above configuration without departing from the gist of the present invention.
For example, in the present embodiment, the external casing support structure 9 has been described using the steam turbine 3 as an example. However, the application target of the above-described external casing support structure 9 is not limited to the steam turbine 3, and any device may be used as long as it is a mechanical device that needs to resist the pressure difference between the inside and the outside. Is possible.

DESCRIPTION OF SYMBOLS 100 ... Steam turbine equipment 1 ... High pressure steam turbine 2 ... Medium pressure steam turbine 3 ... Low pressure steam turbine 3 ... Steam turbine 4 ... Boiler 5 ... Reheater 6 ... Condenser 7 ... Generator 11 ... High pressure turbine rotor 12 ... High pressure Turbine casing 21 ... medium pressure turbine rotor 22 ... medium pressure turbine casing 31 ... low pressure turbine rotor 32 ... low pressure turbine casing 40 ... turbine rotor 31 ... rotor V1 ... main steam valve V2 ... regulating valve 50 ... internal casing 60 ... External compartment 8 ... Stand 8A ... Support opening 9 ... External compartment support structure 51 ... Internal compartment upper half 52 ... Internal compartment lower half 61 ... External compartment body 62 ... External compartment upper half 63 ... External Lower half of vehicle compartment 64 ... Side plate 65 ... Foot 66 ... Outer surface 81 ... Inner surface 65M ... Foot body 67 ... Reinforcement plate 68 ... Stay bar 91 ... engaging portion 92 ... engaging portion 93 ... Spacer 91B ... Bracket 91H ... Bracket body 91S ... Slit forming part S ... Slit H ... Hole part 92B ... Anchor bolt 92S ... Shaft part 92S ... Insertion part 92F ... Head part 92F ... Flange part 82 ... Embedded hole 83 ... Filler 93H ... Insertion hole 93R ... Outer peripheral edge 93C ... Communication hole 19 ... External compartment support structure 192 ... Locking part 192T ... T-shaped steel 191 ... Engagement part 191R ... Recessed groove C ... Filling part 192S ... Support plate part 192L ... Locking plate part B1 ... first protective steel plate B2 ... second protective steel plate S2 ... slit H2 ... hole 193 ... spacer

Claims (10)

An external casing support structure for a steam turbine that supports the lower half of the outer casing of the steam turbine on a frame surrounding the lower half,
An engaging portion that is provided on one of the outer surface of the lower half and the inner surface of the gantry facing each other and that has a hole that opens upward, and a slit that communicates the hole toward the other in the vertical direction; ,
An insertion portion provided on the other of the outer surface of the lower half and the inner surface of the gantry and inserted through the slit, and provided at an end portion on the one side of the insertion portion and inserted in the hole portion. A locking portion having a flange portion protruding from the outer surface of the portion;
An external casing support structure for a steam turbine comprising: The engaging portion is provided on one of the outer surface of the lower half and the inner surface of the gantry facing each other, and a pair of bracket bodies extending toward the other side,
A pair of slit forming portions provided at respective edges on the other side of the pair of bracket main bodies and extending in opposite directions;
Have
The slit is formed between the pair of slit forming portions,
The locking portion is an anchor bolt having a rod-shaped shaft portion and a flange-shaped head,
The structure for supporting an outer casing of a steam turbine according to claim 1, wherein the shaft portion forms the insertion portion, and the head portion forms the flange portion. The engaging portion is a concave groove extending in the vertical direction and having the slit,
The said latching | locking part has a support plate part as the said insertion part extended in an up-down direction, and a latching plate part as the said flange part provided in the edge part of the said support plate part. Support structure for the outer casing of the steam turbine. While interposing between the flange portion and the engagement portion, and having a spacer through which the insertion portion passes,
The through-hole through which the said insertion part is inserted in the said spacer, and the communicating hole which connects this through-hole and the outer periphery edge of the said spacer are formed as described in any one of Claim 1 to 3 Support structure for the outer casing of the steam turbine.   The external casing support structure of the steam turbine according to any one of claims 1 to 4, further comprising a filling portion that is provided inside the engaging portion and fixes the flange portion so as not to move. The engaging part is provided in the lower half part,
The steam turbine external casing support structure according to any one of claims 1 to 5, wherein the locking portion is provided on the inner surface of the gantry. The engaging portion is provided on the inner surface of the gantry,
The steam turbine external casing support structure according to any one of claims 1 to 5, wherein the locking portion is provided in the lower half portion. An external compartment body that houses the internal compartment,
The external casing support structure of the steam turbine according to any one of claims 1 to 7, provided in the external casing main body,
A steam turbine external casing. A rotor that is rotationally driven by steam;
An internal compartment housing the rotor;
The external compartment according to claim 8, which accommodates the internal compartment,
A steam turbine comprising: A steam turbine manufacturing method comprising the steam turbine outer casing support structure according to any one of claims 1 to 7,
Providing the engaging portion on one of the outer surface of the lower half and the inner surface of the gantry facing each other;
Providing the locking portion on the other of the outer surface of the lower half and the inner surface of the gantry;
Lowering the lower half part from above to the inside of the pedestal, inserting the insertion part into the slit, and engaging the flange part with the engagement part;
A method for manufacturing a steam turbine.

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