JP5978633B2 - Manufacturing method of water-cooled wall panel - Google Patents

Description

  The present invention relates to a water-cooled wall panel used for a furnace wall of a boiler installed in a thermal power plant or a waste incinerator.

  As shown in FIG. 9, the water-cooled wall panel P of the boiler furnace is composed of a plurality of tubular pipe sections (water pipes) 1 through which cooling water flows and connecting plates (fins) 5 that connect the water pipes 1. ing. That is, a plurality of water pipes 1 are arranged in parallel at intervals, and fins 5 having a constant width are interposed therebetween, and both ends of the fins 5 are joined to the peripheral wall of the water pipe 1 by fillet welding. It is. A highly corrosion-resistant metal layer 9 such as Inconel having a predetermined thickness or more is formed by overlay welding on the surface of the panel P facing inward of the furnace to prevent corrosion.

  Reference 1 discloses a method for manufacturing a water-cooled wall panel in which fillet welding is performed only on the back surface side of the panel in order to prevent warping of the panel due to overlay welding.

JP2007-155233

  By the way, conventionally, when manufacturing a water-cooled wall panel, overlay welding is given to the panel surface in the state which joined the water pipe and the fin and made the panel. However, in this method, since it is necessary to weld a relatively large panel, the posture of the welding torch or the like cannot be made constant, and there is a problem that the welding conditions are complicated and productivity is lowered. If a plurality of welding electrodes are used to improve productivity, the entire apparatus becomes large and interference between the electrodes becomes a problem.

  Therefore, the present invention solves such a problem, and provides a method for manufacturing a water-cooled wall panel capable of greatly improving productivity without causing interference between electrodes using a compact welding apparatus. With the goal.

In order to achieve the above object, according to the first aspect of the present invention, a plurality of cylindrical pipe sections (1) that allow cooling water to pass therethrough are positioned between the pipe sections (1), and both ends are pipe sections. A method for producing a water-cooled wall panel (P) comprising a connecting plate (5) joined to the peripheral wall of (1), wherein the highly corrosion-resistant metal is welded on the surface of a substantially half circumference of the pipe part (1). A step of forming a layer (4), a step of forming a highly corrosion-resistant metal layer (6) by overlay welding on one plate surface of the connecting plate (5), and the pipe section subjected to overlay welding The substantially half-circumferential surface of (1) and the plate surface of the connecting plate (5) subjected to overlay welding are positioned on the same side, and the side end of the connecting plate (5) is placed around the pipe portion (1). and a step of bonding by fillet welding to the surface, and by limiting the formation range of the conduit section (1) high corrosion resistant metal layer of the surface (4) in the range of less than half When the side end of the connecting plate (5) is brought into contact with the peripheral surface of the pipe part (1) in order to perform fillet welding, the welding material (3) for fillet welding is applied to the contact part. A space (S) for allowing the welding arc (L) to enter is formed.

In the first aspect of the present invention, the high-corrosion-resistant metal layer is formed in advance by overlay welding the pipe line part and the connecting plate before being integrated as the water-cooled wall panel, and the pipe part and the connecting plate are filled with the fillet. Since it joins by welding, it is not necessary to perform overlay welding with respect to a large sized panel conventionally. Therefore, unlike the case of welding to a panel, the welding torch is simply a tube or plate, so the orientation of the welding torch during overlay welding can be kept almost constant, and production is avoided while complicating welding conditions. Can be greatly improved. Further, since it is not necessary to use a plurality of electrodes in order to increase productivity, a compact welding apparatus that does not cause interference between the electrodes can be used. Furthermore, since a fixed space (groove) is formed in the contact portion where the side end of the connecting plate is in contact with the peripheral surface of the pipe line portion, the welding material or the welding arc easily enters the contact portion. The poor fusion of fillet welding can be suppressed and better welding can be performed.

In the second aspect of the present invention, a water-cooled wall panel comprising a plurality of cylindrical pipe sections that allow cooling water to pass therethrough and a connecting plate that is positioned between the pipe sections and whose both ends are joined to the peripheral walls of the pipe sections. The connecting plate is composed of a clad metal plate in which one of the metal plates joined to each other is a highly corrosion-resistant metal plate, and has high corrosion resistance by overlay welding on the surface of a substantially half circumference of the pipe portion. The step of forming a metal layer, and the substantially half-circumferential surface of the pipe line portion subjected to overlay welding and the highly corrosion-resistant metal plate of the connection plate are positioned on the same side, and the side end of the connection plate is connected to the pipe portion A step of joining the peripheral surface of the pipe portion by fillet welding, and limiting the formation range of the highly corrosion-resistant metal layer (4) on the surface of the pipe portion (1) to a range smaller than a half circumference, When the side end of the connecting plate (5) is brought into contact with the peripheral surface of the pipe line portion (1) for application, So as to form a space (S) which penetrate the welding material of the fillet weld (3) and the welding arc (L) in the. In this 2nd invention, since a clad metal plate is used as a connecting plate, in addition to the effects of the 1st invention, there is no need to build-up welding to the connecting plate, so the productivity can be further improved. . In addition, since a constant space (groove) is formed in the abutting portion where the side end of the connecting plate abuts on the peripheral surface of the pipe portion, welding material and welding arc easily enter the abutting portion, The poor fusion of fillet welding can be suppressed and better welding can be performed.

In this 3rd invention , the both ends (41) of the circumferential direction of the said highly corrosion-resistant metal layer (4) formed by overlay welding on the surface of the substantially half circumference of the said pipe part (1) are removed by machining To do.

According to the third aspect of the present invention , since a certain space (groove) is more reliably formed in the contact portion in which the side end of the connecting plate is in contact with the peripheral surface of the duct portion, the weld is welded to the contact portion. It is easy for materials and welding arcs to enter, and it is possible to reliably suppress poor fusion of fillet welding and to perform better welding. In particular, during overlay welding, an oxide layer is formed on the surface of the highly corrosion-resistant metal layer, and this may be the starting point, and cracks may occur during fillet welding. For example, the oxide layer is removed. Here, in the third invention , since the oxide layer is surely removed by machining prior to fillet welding, generation of cracks can be prevented and further satisfactory welding can be performed. As a result, the product life is improved.

  The reference numerals in the parentheses indicate the correspondence with specific means described in the embodiments described later.

  As mentioned above, according to the manufacturing method of the water-cooled wall panel of this invention, productivity can be improved significantly, without producing interference between electrodes using a compact welding apparatus.

It is a perspective view of the water pipe which is constructing overlay welding which shows one embodiment of the present invention. It is a cross-sectional view of a water pipe that has completed overlay welding. It is a perspective view of the fin under construction welding. It is a cross-sectional view of the fin which completed overlay welding. It is a cross-sectional view of the water-cooled wall panel during fillet welding construction. It is a principal part cross-sectional view of the water-cooled wall panel after completion of fillet welding. It is a cross-sectional view of a water pipe showing another embodiment of the present invention. It is a cross-sectional view of the water-cooled wall panel before fillet welding construction. It is a perspective view of the conventional water cooling wall panel.

  The embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

  The method of the present invention is characterized in that overlay welding is performed on a water pipe (pipe section) and fins (connecting plates) before being assembled into a panel. That is, as shown in FIG. 1, the welding torch 2 is reciprocated in the longitudinal direction by sequentially shifting the position of the welding torch 2 in the circumferential direction on the surface of the semi-circular surface of less than 180 degrees with respect to the water pipe 1 made of boiler steel. Therefore, overlay welding by TIG welding is performed. In addition, in the figure, the code | symbol L shows a welding arc and the code | symbol 3 shows the welding material of a high corrosion resistance metal. FIG. 2 shows a cross-sectional view of the water pipe 1 after completion of build-up welding, and a highly corrosion-resistant metal layer 4 having a predetermined thickness or more is formed on the surface of substantially half the circumference of the water pipe 1 less than 180 degrees by build-up welding.

  As shown in FIG. 3, the welding torch 2 is reciprocated in the longitudinal direction by sequentially shifting the position in the width direction in the region excluding both side edges of one surface of the original plate 9 made of boiler steel for cutting out the fins 5. By doing so, overlay welding by TIG welding is performed. FIG. 4 shows a cross-sectional view of the original plate 9 after completion of overlay welding. A high corrosion resistance metal layer 6 having a predetermined thickness or more is formed on the surface of the original plate 9 excluding the side edges 91 by overlay welding. Subsequently, the both side edge 91 portions of the original plate 9 are cut, and the remaining plate portion is cut with a predetermined width perpendicular to the plate surface (chain line in FIG. 4) to obtain a plurality of fins 5.

  The required number of water pipes 1 and fins 5 in which the highly corrosion-resistant metal layers 4 and 6 are formed by overlay welding as described above are prepared. As shown in FIG. 5, both ends of the fins 5 are filled into the water pipe 1 by fillet welding. The water-cooled wall panel P is manufactured by bonding. In the figure, reference numeral 7 denotes a fillet weld. In this case, the welding material 3 forming the fillet weld 7 is the same as the metal material constituting the high corrosion resistance metal layers 4 and 6. When performing fillet welding, as shown in FIG. 5, the side ends of the fins 5 are brought into contact with the radial positions of the water pipe 1. At this time, a fillet weld portion 8 for temporary attachment made of the same metal material as the water tube 1 and the fin 5 is formed on the joint portion back surface side of the water tube 1 and the fin 5. By forming such fillet welds 8, the water pipe 1 and the fins 5 are reliably positioned, so that the fillet welds 7 on the surface side can be formed more quickly and accurately. In the present embodiment, as described above, the build-up welding of the water pipe 1 is made to have a surface with a substantially half circumference of less than 180 degrees, so that the contact portion (joint portion) of the side end of the fin 5 with the water pipe 1 is constant. A space S is formed. And it becomes easy to enter the welding material 3 and the welding arc L in this space S, a fusion defect is suppressed, and fillet welding can be performed more favorably.

  FIG. 6 shows a cross-sectional view of the main part of the completed water-cooled wall panel P. On the surface side of the panel P positioned toward the inside of the boiler furnace, high corrosion-resistant metal layers 4 and 6 having a predetermined thickness and fillet welds 7 made of the same material are formed by overlay welding and fillet welding. ing.

  7 and 8 show another embodiment of the present invention. As shown in FIG. 7, after high-corrosion resistant metal layer 4 is formed on the surface of substantially half the circumference of water tube 1 to form high corrosion-resistant metal layer 4, both ends in the circumferential direction of metal layer 4 are indicated by line L in the figure. Then, they are cut off by machining along parallel tangents at symmetrical positions in the radial direction. In this way, as shown in FIG. 8, a space S having a substantially right corner is formed at the contact portion (joint portion) of the side end of the fin 5 with the water pipe 1. The material 3 and the welding arc L are easier to enter, so that poor fusion is suppressed and fillet welding can be performed more satisfactorily.

  As described above, according to the present embodiment, the water pipe 1 and the fin 5 before being integrated as a panel are subjected to overlay welding to form the high corrosion-resistant metal layers 4 and 6 in advance, and the water pipe 1 and the fin 5 are formed. Since 5 is joined by fillet welding, it is not necessary to perform overlay welding on a large panel as in the prior art. Therefore, unlike the case of welding to a panel, the welding torch is simply a tube or plate, so the orientation of the welding torch during overlay welding can be kept almost constant, and production is avoided while complicating welding conditions. Can be greatly improved. Moreover, the enlargement of the whole welding apparatus can also be avoided. Furthermore, as the fin 5, it is preferable to use a clad material in which a heat-resistant plate is joined to the side surface of the steel for boiler welding.

DESCRIPTION OF SYMBOLS 1 ... Water pipe (pipe part), 2 ... Welding torch, 3 ... Welding material, 4 ... High corrosion-resistant metal layer, 5 ... Fin (connection board), 6 ... High corrosion-resistant metal layer, L ... Welding arc, S ... Space.

Claims (3)

A method for manufacturing a water-cooled wall panel, comprising: a plurality of cylindrical pipe sections that allow cooling water to pass therethrough; and a connecting plate that is positioned between the pipe sections and that has both ends joined to the peripheral walls of the pipe sections. , A step of forming a highly corrosion-resistant metal layer by overlay welding on a substantially half-circumferential surface of the pipe section, a step of forming a highly corrosion-resistant metal layer by overlay welding on one plate surface of the connecting plate, and overlaying The substantially half-circumferential surface of the welded pipe line part and the plate surface of the connecting plate subjected to overlay welding are positioned on the same side, and the side edges of the connecting plate are cornered on the peripheral surface of the pipe part. And forming a high corrosion-resistant metal layer on the surface of the pipe section on the peripheral surface of the pipe section in order to perform fillet welding by limiting the formation range of the highly corrosion-resistant metal layer to less than a half circumference. When the side ends of the connecting plate are brought into contact with each other, a space for allowing a fillet welding material or welding arc to enter the contact portion. Method for producing a water-cooled wall panels to form. A method for manufacturing a water-cooled wall panel, comprising: a plurality of cylindrical pipe sections that allow cooling water to pass therethrough; and a connecting plate that is positioned between the pipe sections and that has both ends joined to the peripheral walls of the pipe sections. The connecting plate is formed of a clad metal plate in which one of the metal plates joined to each other is a highly corrosion-resistant metal plate, and a high corrosion-resistant metal layer is formed on the surface of the substantially half circumference of the pipe portion by overlay welding. And the substantially half-circumferential surface of the pipe line part subjected to overlay welding and the highly corrosion-resistant metal plate of the connecting plate are located on the same side, and the side edges of the connecting plate are filled with the peripheral surface of the pipe part A step of joining by welding, and limiting the formation range of the highly corrosion-resistant metal layer on the surface of the pipe part to a range smaller than a half circumference, and connecting the peripheral part of the pipe part to the peripheral surface in order to perform fillet welding When the side edges of the plate are brought into contact, the fillet welding material or welding arc is allowed to enter the contact portion. Method for producing a water-cooled wall panels so as to form a space. The method for manufacturing a water-cooled wall panel according to claim 1 or 2 , wherein both end portions in the circumferential direction of the highly corrosion-resistant metal layer formed on the surface of the pipe portion are removed by machining.

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