Heat retention device for turbine casing, securing tool for securing heat retention block for turbine casing, and method for securing heat retention block for turbine casing

A securing tool for a heat retention block covering a turbine casing main body includes: a securing rod, one end of which has an engaging portion with a protrusion; and a socket. The socket includes a guide groove, into which the protrusion of the securing rod is inserted, and a recessed groove. The guide groove includes a first guide groove, which extends in the socket axis direction from a starting end to a terminal end, and a second guide groove, the starting end of which is connected to the terminal end, and which extends from the starting end to a terminal end in a circumferential direction relative to the socket axis. The second guide groove is connected to the recessed groove.

TECHNICAL FIELD

The present invention relates to a heat retention device for a turbine casing, a securing tool for securing a heat retention block for a turbine casing, and a method for securing a heat retention block for a turbine casing.

The present application claims priority based on JP 2017-094451 filed in Japan on May 11, 2017, the contents of which are incorporated herein by reference.

BACKGROUND ART

In general, a turbine casing of a steam turbine or a gas turbine (hereinafter collectively referred to as “turbine power generator”) used in a power plant, chemical plant, or the like, is configured by dividing the turbine casing with the center axis of a rotating portion such as a rotor into two sections above and below. The top and bottom casings are fastened together by bolts at respective flanges. A stationary part such as a stator blade is provided on the inner surface of the turbine casing. A rotating portion, such as a rotor having a rotor blade attached thereto, is mounted horizontally inside the turbine casing. The rotating portion is rotatably supported by a bearing provided on the turbine casing.

Here, during operation of a turbine or the like, high-temperature, high-pressure fluid such as gas, or the like flows inside the turbine casing. At this time, the narrower a clearance between a stationary system and a rotating system, the less fluid is leaked, and more energy can be transmitted to the rotating system. An outer surface of the turbine casing is normally covered by a heat retention block made of a heat insulating material, for preventing heat dissipation.

A structure, for example, illustrated inFIG. 4Ais known as an installation structure for such a heat retention block in a turbine casing. Specifically, a plurality of cotton heat insulating material102and a plurality of heat retention blocks103are alternately laminated on the surface of the turbine casing101. Stud bolts104are inserted into each of the plurality of insertion holes105formed in the plurality of heat insulating materials102and the plurality of heat retention blocks103, and the plurality of heat insulating materials102and the plurality of heat retention blocks103are secured to the turbine casing101.

Incidentally, in the turbine generator, the casing is opened during a periodic inspection operation. Therefore, it is necessary to attach and detach the heat retention block from the turbine casing at each time. Therefore, it is desirable that the installation structure of the heat retention block on the turbine casing be a structure that can easily perform the attachment and detachment operation. However, in the securing structure of the heat retention block to the turbine casing illustrated inFIG. 4A, the heat insulating material102and the heat retention block103need to be laminated in multiple layers. This leads a large number of operation steps, and therefore a large number of installation steps are required.

In response to such problems, the present inventors have proposed a heat retention structure for a turbine casing that can be easily and quickly constructed, which can reduce the construction period and reduce the maintenance cost (Patent Document 1).

Specifically, as illustrated inFIG. 4B, the structure includes a net-like member203disposed on a surface of a turbine casing, a heat retention block201disposed covering the surface, and a belt205. A part of the belt205is inserted into a through hole202provided so as to penetrate through the turbine heat retention block201in the thickness direction. A hook204is provided on an end portion of a part of the belt205that is inserted into the through hole202. The net-like member203is locked in the hook204.

CITATION LIST

Patent Document

Patent Document 1: JP 5836155 B

SUMMARY OF INVENTION

Technical Problem

In the heat retention structure for the turbine casing disclosed in Patent Document 1, the construction can be performed as a part of the belt is passed through the through hole of the heat retention block, the hook provided on one end of the belt is hooked to a predetermined location on the network member, and the heat retention block is pressed downward (on the side of the net-like member) while the other end of the belt is pulled upward. Therefore, according to the heat retention structure for the turbine casing disclosed in Patent Document 1, a worker can easily and quickly work for construction, and it is possible to reduce the construction period and reduce the maintenance cost.

On the other hand, in the heat retention structure for the turbine casing disclosed in Patent Document 1, the heat retention block is not adhered to the turbine casing and sufficient heat retention effect cannot be obtained depending on the tightness due to tightening and securing by a fabric belt.

In particular, in the turbine casing, a force acts on the heat retention block attached to the lower casing vertically downward due to gravity (a direction where the heat retention block is moved away from the turbine casing), so it is not possible to secure the adhesion of the heat retention block to the turbine casing without a significant degree of tightening of the belt by repeating attachment and detachment of the heat retention block.

Furthermore, while the securing of the belt is performed by adhering the fabric tape provided at the belt end to the fabric tape attached to the surface of the heat retention block, there is also a concern that the securing strength falls due to the fabric tape deteriorating and the adhesive force weakening.

The present invention has been proposed in view of the above, and an object of the present invention is to provide a heat retention device for a turbine casing, a securing tool for securing a heat retention block for a turbine casing, and a method for securing a heat retention block for a turbine casing that can be easily and quickly installed to and removed from a turbine casing of a turbine power generator used in a power plant or the like and can be used repeatedly.

Solution to Problem

In order to achieve the above-described object, a heat retention device for a turbine casing according to the present invention includes a heat retention block disposed on a surface of a turbine casing main body, a securing rod capable of penetrating the heat retention block in a thickness direction, and a socket secured to the surface of the turbine casing main body. The heat retention block includes a bag body including an insertion hole formed in a predetermined position and inorganic fiber filled into the bag body. The securing rod includes a rod-shaped main body portion inserted into the heat retention block from the insertion hole and penetrating the heat retention block in a thickness direction, and an engaging portion including a pair of protrusions formed on a first end of the main body portion and protruding outward in a radial direction with respect to the rod-shaped main body portion. The socket has a hollow cylindrical shape centered on a socket axis, and an end of a first side in an axial direction where the socket axis extends forms an open end. The socket includes a first guide groove, a second guide groove, and a recessed groove recessed from an inner circumferential surface of the socket toward an outer circumferential side and formed for receiving the protrusion. The first guide groove includes a first starting end in the open end and a first terminal end, and extends in an axial direction from the first starting end to the first terminal end. The second guide groove includes a second starting end leading to the first terminal end and a second terminal end, and extends in a circumferential direction with respect to the socket axis from the second starting end to the second terminal end. The recessed groove leads to the second terminal end and extends in the axial direction from the second terminal end.

The present aspect includes a heat retention block that is filled with inorganic fiber into a bag body including an insertion hole formed in a predetermined position, and is disposed on a surface of a turbine casing main body. With this configuration, heat dissipation from the turbine casing main body can be efficiently prevented by the inorganic fiber. Thus, according to the present aspect, it is possible to increase the heat retention performance of the turbine casing main body.

The present aspect includes a securing rod including an engaging portion including a pair of protrusions. With this configuration, the securing rod is inserted into a protective block from an insertion hole, and the securing rod and the socket are engaged, making it possible to firmly secure the heat retention block to the surface of the turbine casing main body.

A first guide groove extending in the axial direction from the first starting end in the open end to the first terminal end is formed on the inner circumferential surface of the socket of the present aspect. With this configuration, a protrusion of the securing rod can be guided in the axial direction by inserting the protrusion from the first starting end into the first guide groove and moving from the first starting end to the first terminal end.

On the inner circumferential surface of the socket of the present aspect, a second guide groove is formed that extends in the circumferential direction from the second starting end leading to the first terminal end, to the second terminal end. With this configuration, a protrusion of the first guide groove can be guided in the circumferential direction by inserting the protrusion from the second starting end into the second guide groove and moving the protrusion from the second starting end to the second terminal end.

On the inner circumferential surface of the socket of the present aspect, a recessed groove is formed that leads to the second terminal end and extends in the axial direction. With this configuration, the protrusion of the securing rod is engaged with the recessed groove by inserting a protrusion of the second guide groove into the recessed groove and moving in the axial direction. Thus, in the present aspect, the securing rod can be locked to the socket, and the securing rod and the socket are firmly secured.

In the present aspect, the socket is disposed on the surface of the turbine casing main body. With this configuration, when the heat retention block is installed on the surface of the turbine casing main body, the heat retention block can be installed with reference to the socket as a sign. Thus, in the present aspect, positioning of the heat retention block in the turbine casing main body is facilitated.

In a case where the recessed groove extends from the second terminal end toward the turbine casing main body side in the axial direction, the protrusion can be engaged with the recessed groove by a simple pressing operation of the securing rod toward the turbine casing main body side, and the securing rod can be locked to the socket.

In a case where the recessed groove extends from the second terminal end to the open end side of the socket in the axial direction, the protrusion can be engaged with the recessed groove by a simple pulling operation of the securing rod to the open end side, and the securing rod can be locked to the socket.

Here, in the above-described aspects, a flange may be provided that can be inserted into the main body portion of the securing rod and press the heat retention block toward the turbine casing main body side. In this aspect, in a state in which the securing rod is inserted into the heat retention block for the turbine casing, the flange can be pressed from the surface of the heat retention block, so the securing of the heat retention block to the turbine casing main body becomes robust.

In an aspect having a flange, a male thread may be formed on the main body portion of the securing rod, and a nut that secures the flange at a predetermined position of the main body portion may be screwed into the main body portion. In this aspect, the movement of the flange can be restricted by the nut, and thus securing of the heat retention block to the turbine casing main body is robust.

In any of the above aspects, the heat retention block includes a first heat retention block that covers a surface of the turbine casing main body, and a second heat retention block that is laminated via a plate-shaped reinforcing member in a thickness direction of the first heat retention block. The first heat retention block includes a first bag body having an insertion hole formed in a predetermined position and inorganic fiber filled into the first bag body. The second heat retention block includes a second bag body having an insertion hole formed in a predetermined position and inorganic fiber filled into the second bag body. In this aspect, various methods of use are possible, such as changing the material as inorganic fiber in the first heat retention block and the second heat retention block. For example, as the first inorganic fiber that constitutes the first heat retention block that covers the surface of the turbine casing main body, biosoluble fiber having a high heat retention effect are used. On the other hand, as the second inorganic fiber that constitutes the second heat retention block, rock wool with inferior heat retention effect and low raw material cost can be used to balance heat retention and cost.

In a case where the first heat retention block and the second heat retention block are laminated via the plate-shaped reinforcing members, shear deformation of the first heat retention block and the second heat retention block can be prevented, and the laminated state can be maintained for a long period of time.

In a case where biosoluble fiber is filled in the first bag body as the inorganic fiber, heat retention can be further increased.

In a case where rock wool is filled in the second bag as the inorganic fiber, heat retention can be maintained, while raw material cost can be reduced to a low amount.

In a case where the reinforcing member is expanded metal or punched metal, shear deformation of the first heat retention block and the second heat retention block can be reliably prevented.

In order to achieve the above-described object, a securing tool for securing a heat retention block for a turbine casing according to the present invention includes a securing rod and a socket having a hollow cylindrical shape centered on a socket axis and having an open end at an end on a first side in an axial direction where the socket axis extends. The securing rod includes a main body portion that forms a rod shape and includes male thread formed, an engaging portion including a pair of protrusions formed on a first end of the main body portion and protruding outward in a radial direction with respect to the main body portion having a rod shape, a flange insertable into the main body portion, and a nut screwed into the main body portion so as to secure the flange at a predetermined position on the main body portion. The socket includes a first guide groove, a second guide groove, and a recessed groove recessed from an inner circumferential surface of the socket toward an outer circumferential side and formed for receiving the protrusion. The first guide groove includes a first starting end in the open end and a first terminal end, and extends in an axial direction from the first starting end to the first terminal end. The second guide groove includes a second starting end leading to the first terminal end and a second terminal end, and extends in a circumferential direction with respect to the socket axis from the second starting end to the second terminal end. The recessed groove leads to the second terminal end and extends in the axial direction from the second terminal end.

The present aspect includes a securing rod having an engaging portion including a pair of protrusions. With this configuration, the securing rod and the socket described below can be engaged to be undetachable.

The present aspect includes a flange that can be inserted into the main body portion of the securing rod, and a nut that can be engaged with a male thread formed on the main body portion. With this configuration, for example, in a state in which the securing rod is inserted into the heat retention block for the turbine casing, the flange can be pressed from the surface of the heat retention block, and the flange can be secured at a predetermined position on the securing rod. Thus, according to the present aspect, the heat retention block can be rigidly attached to the turbine casing main body.

A first guide groove extending in the axial direction from the first starting end in the open end to the first terminal end is formed on the inner circumferential surface of the socket of the present aspect. With this configuration, a protrusion of the securing rod can be guided in the axial direction by inserting the protrusion from the first starting end into the first guide groove and moving from the first starting end to the first terminal end.

On the inner circumferential surface of the socket of the present aspect, a second guide groove is formed that extends in the circumferential direction from the second starting end leading to the first terminal end, to the second terminal end. With this configuration, a protrusion of the first guide groove can be guided in the circumferential direction by inserting the protrusion from the second starting end into the second guide groove and moving the protrusion from the second starting end to the second terminal end.

On the inner circumferential surface of the socket of the present aspect, a recessed groove is formed that leads to the second terminal end and extends in the axial direction. With this configuration, the protrusion of the securing rod is engaged with the recessed groove by inserting a protrusion of the second guide groove into the recessed groove and moving in the axial direction. Thus, in the present aspect, the securing rod can be locked to the socket, and the securing rod and the socket are firmly secured.

In order to achieve the above-described object, a method for securing a heat retention block for a turbine casing according to the present invention includes the steps of installing a heat retention block on a turbine casing main body, adjusting a position of the heat retention block with respect to a socket disposed on a surface of the turbine casing main body, the socket having a hollow cylindrical shape centered on a socket axis, and the socket including an open end at an end on a first side in an axial direction where the socket axis extends, penetrating a securing rod including an engaging portion through the heat retention block, pressing the securing rod to fit the engaging portion within the socket, rotating the securing rod in a circumferential direction with respect to the socket axis, and engaging the engaging portion with the socket. The heat retention block includes a bag body including an insertion hole formed in a predetermined position and inorganic fiber filled into the bag, and has a thickness from one surface side to another surface side. The securing rod includes a rod-shaped main body portion, and the engaging portion including a pair of protrusions formed on a first end of the main body portion and protruding outward in a radial direction with respect to the rod-shaped main body portion. The socket includes a first guide groove, a second guide groove, and a recessed groove recessed from an inner circumferential surface of the socket toward an outer circumferential side and formed so that the protrusion is inserted. The first guide groove includes a first starting end in the open end and a first terminal end, and extends in an axial direction from the first starting end to the first terminal end. The second guide groove includes a second starting end leading to the first terminal end and a second terminal end, and extends in a circumferential direction with respect to the socket axis from the second starting end to the second terminal end. The recessed groove leads to the second terminal end and extends in the axial direction from the second terminal end. In the step of installing, the other surface side of the heat retention block is brought into contact with a surface of the turbine casing main body. In the step of adjusting, the position of the heat retention block is adjusted to fit the socket into an insertion hole formed at a predetermined position on the other surface side of the heat retention block. In the step of pressing, the protrusion is inserted into the first guide groove from the first starting end of the first guide groove, and the securing rod is pressed to the first terminal end of the first guide groove. In the step of rotating, the protrusion in the first guide groove is inserted into the second guide groove from the second starting end of the second guide groove, and the securing rod is rotated in the circumferential direction to the second terminal end of the second guide groove. In the step of engaging, the protrusion in the second guide groove is placed in the recessed groove.

In the present aspect, the step of installing is performed. With this method, the heat retention block can be installed on the surface of the turbine casing main body.

In the present aspect, the step of positioning is performed. With this method, the heat retention block can be adjusted to the appropriate position.

In this aspect, the step of penetrating is performed. With this method, the securing rod can be penetrated through the heat retention block. At this time, the insertion hole of the heat retention block is positioned to the socket, and thus the engaging portion of the securing rod that penetrates the heat retention block enters the socket from the open end of the socket, and the securing rod can be temporarily secured.

In the present aspect, the step of pressing is performed. With this method, the protrusion of the securing rod can be guided in the axial direction in the socket by a simple pressing operation.

In this aspect, the step of rotating is performed. With this method, the protrusion of the securing rod can be guided in the circumferential direction in the socket by a rotation operation.

In this aspect, the step of engaging is performed. With this method, the securing rod can be locked to the socket by inserting the protrusion of the securing rod into the recessed groove from the second terminal end position of the second guide groove, and thus the securing rod and the socket are firmly secured.

In a case where the step of engaging includes a step of pressing the securing rod from the second terminal end, the securing rod can be locked to the socket by inserting the protrusion of the securing rod in the recessed groove by a simple pressing operation, so the securing rod and the socket are firmly secured.

In a case where the step of engaging includes a step of pulling the securing rod from the second terminal end, the securing rod can be locked to the socket by inserting the protrusion of the securing rod in the recessed groove by a simple pulling operation, so the securing rod and the socket are firmly secured.

Advantageous Effect of Invention

In one aspect of the present invention, the heat retention device can be installed easily and quickly on the turbine casing, and the heat retention device can be used repeatedly.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention relating to a heat retention device for a turbine casing, a securing tool for securing a heat retention block for a turbine casing, and a method for securing a heat retention block for a turbine casing will be described with reference to the drawings.

A heat retention device for a turbine casing according to the present embodiment will be described usingFIG. 1. As illustrated inFIG. 1, for example, a heat retention device1for a turbine casing covers a surface21of a turbine casing main body2of a turbine power generator used in a power plant or the like to retain heat of the turbine casing main body2. The heat retention device1includes a heat retention block3and a securing tool4for securing the heat retention block3to the surface21of the turbine casing main body2.

The heat retention block3includes a first heat retention block3athat directly covers the surface21of the turbine casing main body2, and a plate-shaped reinforcing member33disposed on the first heat retention block3a, a plate-shaped reinforcing member33disposed on the first heat retention block3a, and a second heat retention block3blaminated on the first heat retention block3ain the thickness direction via the reinforcing member33. The first heat retention block3aand the second heat retention block3bare block shaped heat insulating material, and the first heat retention block3aand the second heat retention block3bare sewed and integrated. The first heat retention block3aincludes a first bag body31amade of glass cloth and inorganic fiber32selected from locking wool, biosoluble fiber, or the like filled therein. The second heat retention block3bincludes a second bag body31bmade of glass cloth and inorganic fiber32selected from locking wool, biosoluble fiber, or the like filled therein.

Here, the heat retention block3does not necessarily have to be laminated with the first heat retention block3aand the second heat retention block3b. For example, the heat retention block3may be constituted by any one of the first heat retention block3aor the second heat retention block3bhaving the same thickness as the heat retention block3.

However, by configuring the heat retention block3to have a two-layer structure of the first heat retention block3aand the second heat retention block3b, the inorganic fiber32used in the first heat retention block3aand the second heat retention block3bcan be made different. For example, biosoluble fiber having a high heat retention effect can be filled as the inorganic fiber32used in the first heat retention block3athat covers the surface21of the turbine casing main body2where heat retention effects are more desired. On the other hand, as the inorganic fiber32used in the second heat retention block3b, low cost rock wool, which has a lower heat retention effect than biosoluble fiber, can be filled to ensure a balance between heat retention and cost.

An insertion hole34is formed in each of the first bag body31aand the second bag body31b. The position of the insertion hole34of the second bag body31bcorresponds to the position of the insertion hole34of the first bag body31a. The first heat retention block3aand the second heat retention block3binclude the insertion hole34of the first bag body31aand the insertion hole34of the second bag body31b, and a through hole is formed through the first heat retention block3aand the second heat retention block3b.

Here, it is not necessary that the through holes that penetrate the first heat retention block3aand the second heat retention block3bis formed. However, by forming the through holes, it is easy to perform a penetrating operation of the securing rod41as the securing tool4described below through the first heat retention block3aand the second heat retention block3b.

The reinforcing member33is, for example, expanded metal having a staggered metal surface formed thereon, or punched metal having round mesh formed thereon.

Here, it is not necessary to intervene the reinforcement member33between the first heat retention block3aand the second heat retention block3b. However, in a case where the first heat retention block3aand the second heat retention block3bare secured by sewing alone, shear deformation can occur between the first heat retention block3aand the second heat retention block3b, and the laminated state of the first heat retention block3aand the second heat retention block3bmay not be held for a long period of time. Therefore, the reinforcing member33is preferably interposed from the perspective of preventing shear deformation of the first heat retention block3aand the second heat retention block3band holding the laminated state for a long period of time.

The first heat retention block3aand the second heat retention block3bare laminated in a state shifted in the shearing direction so that a portion thereof protrudes outward so as to have protrusion portions35and35.

Here, it is not necessary that the first heat retention block3aand the second heat retention block3bare laminated so as to have the protrusion portions35and35. The four sides of the first heat retention block3aand the four sides of the second heat retention block3bmay be laminated so as to overlap with each other. However, in a case where the first heat retention block3aand the second heat retention block3bare laminated so as to have the protrusion portion35, when a plurality of heat retention blocks3are disposed in the circumferential direction of the turbine casing main body2, the gaps formed between adjacent heat retention blocks3are stepped, so heat dissipation from the turbine casing main body2can be reduced. Thus, in a case where the first heat retention block3aand the second heat retention block3bare laminated so as to have the protrusion portion35, the heat retention effect can be increased.

The respective heat retention blocks3configured in this manner are disposed on the surface21of the turbine casing main body2, and a fabric tape36is attached to the gaps formed between the adjacent heat retention blocks3.

Here, it is not necessary that the fabric tape36be adhered to the gaps formed between the adjacent heat retention blocks3. However, by attaching the fabric tape36, heat dissipation from the gaps formed between the adjacent heat retention blocks3can be prevented and heat retention can be increased.

The securing tool4secures the heat retention block3to the turbine casing main body2. The securing tool4includes a securing rod41and a socket42welded and fixed to the surface21of the turbine casing main body2.

As illustrated inFIG. 1andFIGS. 2A and 2B, the securing rod41includes a rod-shaped main body portion411, an engaging portion413formed on a first end of the main body portion411and engaged with the socket42, and a handle414formed on a second end of the main body portion411for operating the securing rod41by a worker. The main body portion411is a rod-shaped body that can penetrate into the insertion hole34of the second heat retention block3band the insertion hole34of the second heat retention block3b. A male thread is formed on the outer circumference of the main body portion411. The engaging portion413includes a substantially cylindrical shaft portion and a pair of protrusions412protruding outward from the shaft portion in the radial direction with respect to the rod-shaped main body portion411.

Here, it is not necessary for the second end of the main body portion411to have the handle414. However, by including the handle414, the rotating operation and the like when securing the securing rod41to the socket42, which will be described later, can be facilitated, and the burden on the worker can be reduced.

The securing rod41further includes a grip portion415, a nut417b, a flange416joined to the nut417b, and a nut417a. The grip portion415is configured to crimp the heat retention block3from the surface of the second heat retention block3bin a state in which the main body portion411penetrates into the heat retention block3. The nut417bis screwed into the male thread of the main body portion411. The nut417ais screwed into the main body portion411to adjust the position of the flange416joined to the nut417bwith respect to the main body portion411.

Here, it is not necessary for the securing rod41to include the flange416. However, by including the flange416, the heat retention block3can be pressed against the turbine casing main body2, so the securing of the heat retention block3to the turbine casing main body2can be made stronger.

As the socket42, a socket42aconfigured as illustrated inFIG. 2AandFIG. 3A, and a socket42bconfigured as illustrated inFIG. 2BandFIG. 3Bcan be considered. Each of the sockets42aand42bhas a hollow cylindrical shape centered on the socket axis. Here, the direction in which the socket axis extends is referred to as an axial direction. A first side in the axial direction of the hollow cylindrical sockets42aand42bis open. A second side in the axial direction of the hollow cylindrical sockets42aand42bis sealed. On the inner circumferential surface of each of the sockets42aand42b, a guide groove421with which the protrusion412of the securing rod41can engage, and a recessed groove422leading to the guide groove421for holding the protrusion412in the locked position are formed.

The detailed structures of the guide groove421and the recessed groove422will be described with reference toFIGS. 3A and 3B. The guide groove421is formed to be recessed from the inner circumferential surface of the sockets42aand42btoward the outer circumferential side to engage with the pair of protrusions412of the securing rod41. The guide groove421includes a first guide groove421aand a second guide groove421b. The first guide groove421aincludes a first starting end A1in an open end of the sockets42aand42band a first terminal end B1. The first guide groove421aextends in the axial direction where the socket axis extends from the first starting end A1to the first terminal end B1. The second guide groove421bincludes a second starting end A2leading to the first terminal end B1and a second terminal end B2. The second guide groove421bextends in the circumferential direction where the socket axis from the second starting end A2to the second terminal end B2.

Similar to the guide groove421, the recessed groove422is formed to be recessed from the inner circumferential surface of each of the sockets42aand42btoward the outer circumferential side so as to engage the pair of protrusions412of the securing rod41. This recessed groove422leads to the second terminal end B2of the second guide groove421band extends in the axial direction. Note that the recessed groove422of the socket42aof the specifications illustrated inFIG. 2AandFIG. 3Aleads to the second terminal end B2of the second guide groove421b, and extends from the second terminal end B2to the sealed end side, that is, to the side of the turbine casing main body2. The recessed groove422of the socket42bconfigured as illustrated inFIG. 2BandFIG. 3Bleads to the second terminal end B2of the second guide groove421band extends from the second terminal end B2to the open end side of the socket42b. Which of the socket42aand the socket42bwith different specifications are used is selected depending on whether the socket is disposed in the upper turbine casing main body2or the socket is disposed in the lower turbine casing main body2.

For example, as a socket disposed in the upper turbine casing main body2of the turbine casing main body2divided in the vertical direction, the socket42ain which the recessed groove422extends toward the turbine casing main body2is used. For the socket42adisposed in the upper turbine casing main body2, the securing rod41is inserted from the vertically upward direction toward the downward direction. In a state in which the securing rod41is inserted into the socket42a, a force to the upper turbine casing main body2side acts on the securing rod41by the effect of gravity. The recessed groove422of the socket42aextends from the second terminal end B2of the second guide groove421btoward the upper turbine casing main body2side. Thus, the engaging state of the protrusion412of the securing rod41to the recessed groove422is not likely to be released.

On the other hand, as a socket disposed in the lower turbine casing main body2of the turbine casing main body2divided in the vertical direction, the socket42bis used in which the recessed groove422is formed toward the open end side. For the socket42bdisposed in the lower side of turbine casing main body2, the securing rod41is inserted from the vertically downward direction toward the upward direction. In a state in which the securing rod41is inserted into the socket42b, a force acts on the securing rod41in a direction away from the lower turbine casing main body2due to the effect of gravity. The recessed groove422of the socket42bextends in a direction away from the lower turbine casing main body2, which is the open end side of the socket42bfrom the second terminal end B2of the second guide groove421b. Thus, the engaging state of the protrusion412of the securing rod41to the recessed groove422is not likely to be released.

Next, a method of securing the heat retention block3to the turbine casing main body2will be described.

Installing Step of Heat Retention Block

First, in the retention block3, the first heat retention block3ais placed on the surface21of the turbine casing main body2so that the rear surface (other surface) of the first heat retention block3ais in contact with the surface21.

Position Adjusting Step

In the step of installing the heat retention block3, when the heat retention block3is placed on the surface21of the turbine casing main body2, the position of the heat retention block3is adjusted so that the socket42disposed on the surface21of the turbine casing main body2fits into the insertion hole34formed in the rear surface (other surface) of the first bag body31aof the first heat retention block3a.

Penetrating Step

In the adjusting step, when the positioning of the heat retention block3on the surface21of the turbine casing main body2is completed, the front surface side of the second bag body31bof the second heat retention block3bis temporarily held with one hand of the worker, and in this state the securing rod41is inserted into the heat retention block3from the engaging portion413side including the protrusion412in the insertion hole34formed in the second bag body31bof the second heat retention block3bwith the other hand, and the securing rod41is penetrated into the heat retention block3. Then, the protrusion412of the securing rod41is inserted into the first guide groove421afrom the first starting end A1of the socket42.

Flange Pressing Step

In the inserting step, the position of the flange416is adjusted so that the nuts417aand417bare screwed into the main body portion411of the securing rod41in a state that the securing rod41is inserted into the heat retention block3so that the heat retention block3is pressed by the flange416.

Pressing Step

When the engaging state of the first starting end A1and the protrusion412is confirmed, the securing rod41is pressed. With this pressing operation, the protrusion412of the securing rod41slides until the protrusion abuts the first terminal end B1while being guided by the first guide groove421aof the socket42.

Rotating Step

The pressing step rotates the securing rod41to one side in the circumferential direction (clockwise or counterclockwise) with respect to the socket axis once the abutting of the protrusion412to the first terminal end B1is confirmed. With this rotating operation, the protrusion412in the first guide groove421ais inserted from the second starting end A2of the socket42into the second guide groove421band slides until the protrusion abuts the second terminal end B2while being guided by the second guide groove421b.

Engaging Step

The rotating operation step causes the securing rod41to be pressed or pulled once the abutting of the protrusion412to the second terminal end B2is confirmed. This pushing or pulling operation causes the protrusion412of the securing rod41to engage with the recessed groove422recessed from the second terminal end B2. This completes the locking of the securing rod41to the socket42.

For example, as described above, the recessed groove422of the socket42adisposed in the upper turbine casing main body2of the turbine casing main body2divided in the vertical direction extends from the second terminal end B2toward the turbine casing main body2in the axial direction. Thus, when the abutting of the protrusion412to the second terminal end B2is confirmed, the protrusion412can be engaged with the recessed groove422by pressing the securing rod41.

On the other hand, as described above, the recessed groove422of the socket42bdisposed in the lower turbine casing main body2of the turbine casing main body2divided in the vertical direction extends from the second terminal end B2to the open end side of the socket42bin the axial direction. Thus, when the abutting of the protrusion412to the second terminal end B2is confirmed, the protrusion412can be engaged with the recessed groove422by pulling the securing rod41.

As described above, with the heat retention device for the turbine casing according to the present embodiment, it is possible to easily and quickly install and remove the turbine casing of a turbine power generator used in a power plant or the like, and the heat retention device can be used repeatedly.

INDUSTRIAL APPLICABILITY

In one aspect of the present invention, the heat retention device can be installed easily and quickly on the turbine casing, and the heat retention device can be used repeatedly.

REFERENCE SIGNS LIST