JP6596312B2 - Nozzle protection structure, boiler having the same, and method for manufacturing the nose protection structure - Google Patents

Description

  The present invention relates to a nozzle protection structure, a boiler having the same, and a method for manufacturing the nozzle protection structure.

  The boiler has a furnace that has a hollow shape and is installed in the vertical direction, and a plurality of combustion burners are arranged along the circumferential direction on the furnace wall. The coal-fired boiler has a flue connected vertically above the furnace, and a heat exchanger for generating steam is disposed in the flue. Therefore, a flame is formed when the combustion burner injects a mixture of fuel and air into the furnace, and combustion gas is generated and flows into the flue. Then, water flowing through the heat exchanger is heated by the combustion gas generated by the combustion to generate steam.

  Here, the boiler which burns solid fuels, such as coal and biomass, contains many combustion ash in combustion gas. In Patent Documents 1 and 2, a refractory material is disposed in a region where combustion ash flows, such as a heat transfer tube disposed in a furnace, an external heat exchanger, etc., and an object in which the refractory material is disposed contacts the combustion ash. The structure which suppresses wearing by doing is described. Further, Patent Document 2 describes that a refractory material is selectively disposed on the upstream side in the flow direction of the combustion gas that is easily affected by the wear caused by the combustion ash.

JP2012-58182A Japanese Utility Model Publication No. 03-005008

  Moreover, as a countermeasure against wear due to combustion ash, there is a structure in which a wear prevention plate of a plate-like member is disposed around an object. Here, there is a boiler in which a nozzle connected to a heat transfer tube of a heat exchanger and a header (header) connected to a plurality of nozzles are arranged inside a furnace. In this boiler, a wear prevention plate is arranged on the nozzle, and in the vicinity of the connection portion between the nozzle and the header, the wear prevention plate is prevented in order to prevent contact between the wear prevention plate and the header due to thermal elongation during operation. A gap is provided between the pipe and the header. Therefore, even if the wear prevention plate is provided, wear may occur on the nozzle or the like exposed in the gap portion between the wear prevention plate and the header. In particular, in order to suppress the deterioration of heat transfer characteristics due to the accumulation of combustion ash on the heat transfer tubes of the heat exchanger, it was injected when removing the combustion ash deposited on the heat transfer tubes by spraying steam etc. with a suit blower In some cases, combustion ash is entrained in the steam, and wear may occur on the nozzles exposed in the gap portion. When wear occurs, the nozzles need to be replaced or the nozzles need to be repaired, and the frequency of maintenance increases.

  This invention solves the subject mentioned above, and aims at providing the manufacturing method of a nozzle protecting structure which can protect a nozzle from abrasion, a boiler which has this, and a nozzle protecting structure.

  In order to achieve the above object, the nozzle protection structure includes a header and a nozzle attached to the header provided in a combustion gas passage through which combustion gas generated by burning fuel flows. A nozzle protection structure installed in a header, a plurality of strips installed on the outer periphery of the header, a plurality of refractory support fixtures fixed to the strip, and the fireproof A refractory material supported by a material support fitting and covering at least a connecting portion of the nozzle with the header.

  The nozzle protection structure can cover the periphery of the nozzle with a refractory material by providing a refractory support bracket on the band plate and disposing the refractory material around the header nozzle with the refractory support bracket. Thereby, it can suppress that a nozzle is worn. In addition, by providing a refractory support bracket on the strip arranged on the outer periphery of the header, the temperature difference generated by the heat conduction from the header at the base of the refractory support bracket when the boiler starts and stops. Since it does not receive the influence of the thermal fatigue which is anxious about being produced, durability as an apparatus can be made high.

  Here, it is preferable that the refractory material is disposed only in a part including a region on the upstream side in a direction in which a gas that generates wear of the nozzle is flowing in the circumferential direction of the header. As a result, the refractory material can be selectively disposed in a portion requiring protection, the weight of the refractory material in the entire nozzle protection structure can be reduced, and the wear of the nozzle is suppressed. be able to.

  Further, the gas that causes wear of the nozzle is an injection gas from an injection device, and the refractory material is in a range of 60 ° to 180 ° in a circumferential direction centering on an axis of the header nozzle. It is preferable to arrange | position. Thereby, the weight of a refractory material can be reduced.

  The nozzle protection structure has a wear prevention plate supported by at least a part of the nozzle, and the refractory material includes a gap formed between the wear prevention plate and the header. It is preferable to arrange | position. Thereby, abrasion of the nozzle can be prevented by the wear prevention plate. Further, by covering the gap between the wear prevention plate and the nozzle head with a refractory material, it is possible to suppress the wear of the nozzle at the portion corresponding to the gap.

  Moreover, it is preferable that the refractory material support metal fitting has a Y shape in which one end of one bar is fixed to the band plate and the other end of the bar branches into two. By making the refractory material support fitting Y-shaped, the refractory material can be held more reliably.

  The nozzle protection structure has an injection device that injects gas toward the header nozzle at a position facing the header nozzle, and the gas that causes wear of the nozzle is the injection device. It is preferable that the refractory material, which is a gas to be jetted from, is disposed in a range including a position where the distance from the jetting device of the header is closest. Thereby, the gas injected from an injection apparatus can be interrupted | blocked with a refractory material, and it can suppress that a nozzle is worn.

  Moreover, it is preferable that the said refractory material covers the range including the range which can be tied with the injection position of the said injection apparatus without being interrupted by other members among the outer surfaces of the said header. Thereby, the gas injected from an injection apparatus can be interrupted | blocked with a refractory material, and it can suppress that a nozzle is worn.

  To achieve the above object, a boiler includes a combustion gas passage through which combustion gas flows, a header installed in the combustion gas passage, and a plurality of nozzles connected to the header. It has a stand, and the nozzle protection structure in any one of said above installed in the said nozzle head. Thereby, abrasion of a nozzle can be prevented, the frequency of a maintenance can be reduced, and the effort of a maintenance can be reduced.

  In order to achieve the above object, a method of manufacturing a nozzle protecting structure includes a header and a plurality of headers attached to the header in a combustion gas passage through which a combustion gas generated by burning fuel flows. A step of installing a refractory material support bracket on a plurality of strip plates, and a step of installing the strip plate on which the refractory material support brackets are installed on the header plate And a step of applying a refractory material to the strip, and the refractory material is an upstream region in a circumferential direction of the header nozzle in a direction in which a gas that causes wear of the nozzle flows. It is characterized by being arranged only in a part including.

  By providing a refractory material support bracket on the band plate and disposing the refractory material around the header nozzle with the refractory material support bracket, the periphery of the nozzle can be covered with the refractory material. Thereby, it can suppress that a nozzle is worn. Moreover, by providing a refractory material support bracket on the band plate installed on the outer periphery of the header, it can be prepared in advance and the work can be simplified. In addition, by providing a refractory support bracket on the strip, when the boiler starts and stops, the base part of the refractory support bracket has a temperature difference that occurs due to heat conduction from the header. Since it is not received, a highly durable device can be manufactured.

  According to the present invention, the refractory material support fitting is provided on the band plate, and the refractory material is disposed around the header by the refractory support bracket, so that the periphery of the nozzle can be covered with the refractory material. Thereby, it can suppress that a nozzle is worn. In addition, by installing a refractory support bracket on the strip installed on the outer periphery of the header, the effect of thermal fatigue, which is a concern due to a temperature difference at the base of the refractory support bracket when the boiler starts and stops, Therefore, the durability of the refractory material support structure can be increased.

FIG. 1 is a schematic configuration diagram illustrating a coal fired boiler according to the present embodiment. FIG. 2 is a schematic diagram showing a heat exchanger provided in a coal fired boiler. FIG. 3 is a schematic diagram showing a schematic configuration of a nozzle, an inlet header, and a nozzle protection structure. FIG. 4 is a schematic diagram showing a schematic configuration of the nozzle protecting structure. FIG. 5 is a perspective view showing a schematic configuration of the inlet header and the strip. FIG. 6 is a schematic diagram showing a band plate and a Y-shaped anchor stud. FIG. 7 is a schematic diagram showing a schematic configuration of a Y-shaped anchor stud. FIG. 8 is a schematic diagram showing a schematic configuration of the refractory material. FIG. 9 is a schematic diagram showing the relationship between the inlet header and the suit blower. 10 is a cross-sectional view taken along line AA in FIG. 11 is a cross-sectional view taken along line BB in FIG. FIG. 12 is a flowchart showing an example of a manufacturing method of the nozzle protection structure.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

  FIG. 1 is a schematic configuration diagram illustrating a coal fired boiler according to the present embodiment.

  The boiler of this embodiment is a coal fired boiler that uses pulverized coal obtained by pulverizing coal as pulverized fuel (solid fuel), burns the pulverized coal with a combustion burner, and recovers the heat generated by the combustion. is there.

  In this embodiment, as shown in FIG. 1, the coal fired boiler 10 has a furnace 11, a combustion device 12, and a flue 13. The furnace 11 has a rectangular hollow shape and is installed along the vertical direction. The furnace wall constituting the furnace 11 is constituted by a heat transfer tube.

  The combustion device 12 is provided in a lower part of a furnace wall (heat transfer tube) constituting the furnace 11. In the present embodiment, the combustion device 12 has a plurality of combustion burners (for example, 21, 22, 23, 24, 25) mounted on the furnace wall. A plurality of the combustion burners 21, 22, 23, 24, and 25 are arranged at equal intervals along the circumferential direction. However, the shape of the furnace, the number of combustion burners in one stage, and the number of stages are not limited to this embodiment.

  The combustion burners 21, 22, 23, 24, 25 are fed to pulverizers (pulverized coal machines / mills) 31, 32, 33, 34, 35 via pulverized coal supply pipes 26, 27, 28, 29, 30. It is connected. Although not shown, the pulverizers 31, 32, 33, 34, and 35 are, for example, supported so that the pulverization table can be driven and rotated. The pulverization table and the pulverization rollers allow the coal to move between the pulverization rollers and the pulverization table. When put in between, the pulverized coal pulverized to a predetermined pulverized size and classified by the conveying air is supplied from the pulverized coal supply pipes 26, 27, 28, 29, 30 to the combustion burners 21, 22, 23. , 24, 25.

  Further, the furnace 11 is provided with a wind box 36 at the mounting position of each combustion burner 21, 22, 23, 24, 25, and one end portion of an air duct 37 is connected to the wind box 36, and this air The duct 37 has a blower 38 attached to the other end.

  The flue 13 is connected to the upper part of the furnace 11 in the vertical direction. This flue 13 serves as a heat exchanger for recovering the heat of exhaust gas, such as superheaters (superheaters) 41, 42, 43, reheaters (reheaters) 44, 45, and economizers 46, 47. Is provided, and heat exchange is performed between the combustion gas generated by the combustion in the furnace 11 and the water flowing through each heat exchanger.

  The flue 13 is connected to a gas duct 48 through which the combustion gas that has exchanged heat is discharged downstream. This gas duct 48 is provided with an air heater 49 between the air duct 37 and performs heat exchange between the air flowing through the air duct 37 and the combustion gas flowing through the gas duct 48, and the combustion burners 21, 22, 23, 24. , 25 can raise the temperature of combustion air.

  The flue 13 is provided with a denitration catalyst 50 at a position upstream of the air heater 49. The denitration catalyst 50 supplies a reducing agent having an action of reducing nitrogen oxides such as ammonia and urea water into the flue 13, and reacts the combustion gas supplied with the reducing agent with the nitrogen oxides and the reducing agent. By promoting, nitrogen oxides in the combustion gas are removed and reduced. The gas duct 48 connected to the flue 13 is provided with a dust treatment device (electric dust collector, desulfurization device) 51 and an induction blower 52 at a position downstream of the air heater 49, and with a chimney 53 at the downstream end. Yes.

  Therefore, when the pulverizers 31, 32, 33, 34, and 35 are driven, the generated pulverized coal together with the carrier air passes through the pulverized coal supply pipes 26, 27, 28, 29, 30 and the combustion burners 21, 22, 23, 24. , 25. Also, heated combustion air is supplied from the air duct 37 to the combustion burners 21, 22, 23, 24, 25 via the wind box 36. Then, the combustion burners 21, 22, 23, 24, and 25 blow the pulverized fuel mixture mixed with the pulverized coal and the carrier air into the furnace 11 and blow the combustion air into the furnace 11 and ignite at this time. Can form a flame. When a flame is generated, the combustion gas rises in the furnace 11 and is discharged to the flue 13.

  Thereafter, the combustion gas is subjected to heat exchange in the superheaters 41, 42, 43, the reheaters 44, 45, and the economizers 46, 47 disposed in the flue 13, and then the nitrogen oxides are reduced and removed by the denitration catalyst 50. After the particulate matter is removed and the sulfur content is removed by the dust treatment device 51, the dust is discharged from the chimney 53 to the atmosphere.

  Here, the superheaters 41, 42, 43, the reheaters 44, 45, and the economizers 46, 47 provided in the flue 13 will be described in detail as heat exchangers. FIG. 2 is a schematic diagram showing a heat exchanger provided in a coal fired boiler.

  As shown in FIG. 2, the flue 13 is provided with a combustion gas passage 60 through which combustion gas passes, and the combustion gas passage 60 has superheaters 41, 42, 43, reheaters 44, 45, The economizers 46 and 47 are arranged. In addition, since the superheaters 41, 42, and 43 are provided in series via a header, this header is omitted in FIG.

  A steam turbine 61 that is operated by steam generated in the coal-fired boiler 10 includes, for example, a high-pressure turbine 62 and a low-pressure turbine 63. A condenser 64 is connected to the low-pressure turbine 63, and steam that has driven the low-pressure turbine 63 is cooled by cooling water (for example, seawater) in the condenser 64 to become condensed water. The condenser 64 is connected to the inlet header 65 of the first economizer 47 through the water supply line L1. The inlet header 65 is provided in the combustion gas passage 60, and the water supply line L <b> 1 is provided with a water supply pump 66 outside the combustion gas passage 60. The second economizer 46 is disposed above the first economizer 47, and an intermediate header 67 is provided between the economizers 46 and 47. The second economizer 46 has an outlet header 68 connected to the top thereof, and the outlet header 68 is disposed outside the combustion gas passage 60.

  The outlet header 68 is connected to a steam drum 69 disposed outside the combustion gas passage 60 via a water supply line L2. The steam drum 69 is connected to each heat transfer tube (not shown) on the furnace wall, and is connected to superheaters 41, 42, and 43. The superheaters 41, 42, and 43 are high-pressure via a steam line L3. The turbine 62 is connected. And the high pressure turbine 62 is connected with the inlet header (pipe header) 71 of the 1st reheater 45 via the steam line L4. The inlet header 71 is provided in the combustion gas passage 60, the first reheater 45 is connected to the second reheater 44 via the intermediate header 72, and the second reheater 44 is connected to the upper outlet. A header 73 is connected, and the intermediate header 72 and the outlet header 73 are disposed outside the combustion gas passage 60. The outlet header 73 is connected to the low-pressure turbine 63 via the steam line L5.

  Therefore, when the combustion gas flows through the combustion gas passage 60 of the flue 13, this combustion gas is recovered in the order of the superheaters 41, 42, 43, the reheaters 44, 45, and the economizers 46, 47. On the other hand, the water supplied from the water supply pump 66 is preheated by the economizers 47 and 46, then supplied to the steam drum 69, and heated to become saturated steam while being supplied to each heat transfer tube on the furnace wall. Returned to the steam drum 69. The saturated steam of the steam drum 69 is introduced into the superheaters 41, 42, and 43 and is superheated by the combustion gas. The superheated steam generated by the superheaters 41, 42, 43 is supplied to the high pressure turbine 62 and rotationally drives the high pressure turbine 62. The steam discharged from the high-pressure turbine 62 is introduced into the reheaters 45 and 44 and superheated again, and then supplied to the low-pressure turbine 63 to rotate the low-pressure turbine 63. The steam discharged from the low-pressure turbine 63 is cooled by the condenser 64 to become condensed water, and is sent to the economizers 47 and 46 again.

  In the flue 13, a suit blower (injection device) 80 is disposed between the inlet header 71 and the economizer 47. The suit blower 80 extends in a direction parallel to the longitudinal direction of the inlet header 71. The suit blower 80 injects steam in a direction orthogonal to the axial direction with the longitudinal direction of the inlet header 71 as the axial direction, and the injection direction can also vary. The steam sprayed from the suit blower 80 toward the economizer 47 removes the combustion ash deposited on the surface of the heat transfer tube of the economizer 47. Further, the steam injected from the suit blower 80 also reaches the inlet header 71. Since the suit blower 80 is disposed at a position facing the inlet header 71, the suit blower 80 is an injection device that injects gas (steam) not only toward the surface of the heat transfer tube of the economizer 47 but also toward the inlet header 71.

  Hereinafter, the wear suppression structure provided in the inlet header 71 of this embodiment will be described in detail with reference to FIGS. 3 to 8 in addition to FIG. 2. FIG. 3 is a schematic diagram showing a schematic configuration of a nozzle, an inlet header, and a nozzle protection structure. FIG. 4 is a schematic diagram showing a schematic configuration of the nozzle protecting structure. FIG. 5 is a perspective view showing a schematic configuration of the inlet header and the strip. FIG. 6 is a schematic diagram showing a band plate and a Y-shaped anchor stud. FIG. 7 is a schematic diagram showing a schematic configuration of a Y-shaped anchor stud. FIG. 8 is a schematic diagram showing a schematic configuration of the refractory material.

  First, the inlet header 71 is disposed inside the combustion gas passage 60. The inlet header 71 is disposed at a position downstream of the large number of heat transfer tubes of the reheater 45 and upstream of the large number of heat transfer tubes of the economizer 47 in the combustion gas flow direction. The inlet header 71 has a hollow cylindrical shape in which the horizontal direction is the axial direction, and a heat medium is stored therein. The inlet header 71 is connected to the heat exchanger tube 75 of the reheater 45 via a nozzle base 74. The nozzle 74 is a pipe, one end of which is connected to the heat transfer tube 75 and the other end is connected to the inlet header 71. The nozzle 74 is fixed to the heat transfer tube 75 and the inlet header 71 by welding or the like. A number of nozzles 74 are connected to the inlet header 71. A number of nozzles 74 are connected to the heat transfer tubes 75. The inlet header 71 is a header to which a large number of nozzles 74 are thus connected. The inlet header 71 supplies steam, which is a heat medium, to the heat transfer tube 75 through the nozzle pedestal 74. 2 to 8 schematically show the nozzles connected to the inlet header 71, and the number and positions connected to the inlet header 71 are not limited to the drawings. .

  The nozzle protecting structure 90 is disposed with respect to the inlet header 71 and the nozzle 74. Here, a structure in which a large number of nozzles 74 are connected to the inlet header 71 is referred to as a header nozzle 70. The nozzle protection structure 90 is disposed with respect to the header nozzle 70. The nozzle protecting structure 90 is a structure that suppresses the occurrence of wear on the nozzle 74 connected to the inlet header 71. The nozzle protection structure 90 includes a plate unit 92 and a refractory material unit 94. When the design pressure is not high, the nozzle 74 has a thin thickness of about several millimeters, and there is no margin for thinning against wear. Therefore, the nozzle protection structure 90 is effective as a partial wear countermeasure. It is.

  The plate unit 92 is disposed on at least some of the nozzles 74 among the many nozzles 74. Specifically, the plate unit 92 includes at least a nozzle 74 disposed at the upstream end in the combustion gas flow direction and a nozzle 74 disposed at the downstream end. Has been placed. The plate unit 92 includes a wear prevention plate 96 and a fixing portion 98. The wear prevention plate 96 is disposed on the surface of the nozzle 74 where the cause of wear is supplied. Specifically, when the wear prevention plate 96 is installed on the nozzle 74 disposed at the upstream end of the combustion gas flow direction, the wear prevention plate 96 is disposed upstream of the nozzle 74 in the combustion gas flow direction. Is done. When the wear prevention plate 96 is installed in the nozzle 74 disposed at the downstream end of the combustion gas flow direction, the wear prevention plate 96 is disposed downstream of the nozzle 74 in the combustion gas flow direction. The wear prevention plate 96 has a semicircular shape with a cross section curved along the outer periphery of the nozzle 74. The cross-sectional shape of the wear preventing plate 96 is not limited to a semicircular shape (arc angle is about 180 °), but may be a fan shape (arc angle is about 120 ° to 180 °). The fixing part 98 installs the wear prevention plate 96 on the nozzle 74. The wear prevention plate 96 is disposed up to the vicinity of the inlet header 71. In order to prevent contact between the wear prevention plate 96 and the inlet header 71 due to thermal expansion during operation, the wear prevention plate 96 is disposed in a non-contact manner. ing. For this reason, a gap 99 is formed between the wear prevention plate 96 and the inlet header 71. Since the gap 99 is not protected by the wear prevention plate 96, the nozzle 74 existing in the gap 99 may be worn and thinned.

  The refractory material unit 94 is disposed around the header head 70. The refractory material unit 94 includes a plurality of strips 102, a plurality of Y-shaped anchor studs 104, an electrolytic lath 106, and a refractory material 108. If the refractory material unit 94 is a small size, the electrolytic lath 106 may be omitted.

  The plurality of strips 102 include a plurality of axial plates 112 and a plurality of circumferential plates 114 as shown in FIGS. 3 to 5, particularly FIG. 5. The axial plate 112 is a plate whose longitudinal direction is the axial direction (longitudinal direction) of the inlet header 71 of the nozzle head 70. The plurality of axial plates 112 are arranged at intervals in the circumferential direction of the inlet header 71. The circumferential plate 114 is a plate whose longitudinal direction is the circumferential direction of the inlet header 71. The circumferential plate 114 is a ring-shaped plate disposed on the entire circumference of the inlet header 71 in the circumferential direction. The plurality of circumferential plates 114 are arranged at intervals in the axial direction of the inlet header 71. The axial direction plate 112 and the circumferential direction plate 114 are fixed by a welded portion 116 provided at an overlapping position. The strip 102 uses, for example, a low chromium-containing high-temperature steel plate, but may be a general structural steel plate material such as SS400 in a low temperature region. For example, the band plate 102 has a plate thickness of about 3 mm to 6 mm and a plate width of about 20 mm to 60 mm.

  The axial direction plate 112 and the circumferential direction plate 114 of the band plate 102 are arranged at positions shifted from the position where the nozzle base 74 of the header nozzle 70 is arranged. That is, the axial direction plate 112 and the circumferential direction plate 114 are disposed on the surface of the inlet header 71 with the nozzle 74 being away from it. In the band plate 102, the axial plate 112 and the circumferential plate 114 are fixed by the welded portion 116, and the header plate 70 is not fixed by welding or a jig. Therefore, the strip 102 is in contact with the header nozzle 70 but is not fixed.

  The plurality of Y-shaped anchor studs 104 are respectively fixed to the band plate 102 (the axial direction plate 112 and the circumferential direction plate 114). As shown in FIGS. 3 and 4, the Y-shaped anchor stud 104 is fixed to the strip plate 102 and protrudes in a direction away from the surface of the inlet header 71. As shown in FIG. 6, a plurality of Y-shaped anchor studs 104 are arranged in a row on one band plate 102. The direction of the Y-shaped surface of the Y-shaped anchor stud 104 is set so as to be along the longitudinal direction of the band plate 102 and has an angle of 45 ° to 90 ° with respect to the longitudinal direction of the band plate 102. Thus, the holding power in a plurality of directions of the refractory material 108 is improved. The Y-shaped anchor stud 104 is arranged only in a range where the refractory material 108 is provided in the circumferential direction of the inlet header 71.

  As shown in FIG. 7, the Y-shaped anchor stud 104 includes a straight portion 130, two branch portions 132, and a base 134. The straight portion 130 is a rod-shaped member, and two branch portions 132 are fixed to one end portion, and a base 134 is fixed to the other end portion. The two branch portions 132 are rod-shaped members, and one end portion is fixed to the straight portion 130. The two branch portions 132 are inclined in directions that are symmetric with respect to the axial direction of the straight portion 130. The base 134 is a plate member that extends on a surface orthogonal to the axial direction of the straight portion 130, one surface is fixed to the straight portion 130, and the other surface is fixed to the band plate 102 by welding or the like. Thus, the Y-shaped anchor stud 104 has a Y-shape formed by the straight portion 130 and the two branch portions 132, and is fixed to the band plate 102 by the base 134. Moreover, the several Y-shaped anchor stud 104 arrange | positioned at the same strip shown in FIG. 6 is arrange | positioned by changing the direction of the branch part 132 according to a position.

  As shown in FIG. 4, the electrofused lath 106 is disposed on the distal end side of the Y-shaped anchor stud 104, that is, on the branching portion 132 side. The electroconductive lath 106 is arranged only in a range where the refractory material 108 is provided in the circumferential direction of the inlet header 71. Electrolytic lath 106 is a member in which a metal mesh is formed, for example, a wire mesh. In this embodiment, the electromelting lath 106 is used, but an opening that can be hooked on the Y-shaped anchor stud 104 and through which the refractory material 108 can pass when the refractory material 108 is applied is formed. Any mesh member may be used.

  As shown in FIG. 3, the refractory material 108 is installed so as to fill at least the gap 99 between the wear prevention plate 96 and the inlet header 71. The refractory material 108 is provided in a range covering the periphery of the Y-shaped anchor stud 104 and the electroformed lath 106 fixed to the strip plate 102. Further, as shown in FIG. 8, the refractory material 108 is divided into a plurality of refractory material blocks 108 a at predetermined intervals in the axial direction of the inlet header 71. The predetermined interval thus divided is, for example, 0.5 m to 1 m, and a gap 142 is provided between the refractory material block 108a and the refractory material block 108a. The gap 142 is, for example, about 3 mm to 10 mm. The gap 142 is preferably a portion where the nozzle 74 does not exist. Thereby, even when displacement occurs in the mutual positional relationship due to a difference in thermal expansion between the refractory material 108 during operation of the boiler 10 and the header pedestal 70, the influence is suppressed and the refractory material is prevented from falling off. be able to. As the refractory material 108, for example, a phosphate refractory manufactured by using a phosphate as a binder for a material containing alumina and silica can be used. Phosphate refractories have high hardness and can be dried in a few hours under a normal temperature atmosphere, so that the boiler 10 can be ignited at an early stage after construction. Therefore, partial repair and emergency repair of the refractory material 108 are possible. This is preferable because it is possible to cope with the situation. The refractory material 108 is not limited to a phosphate refractory material, and may be any material as long as it has a hardness that can withstand practical use by protecting the nozzle 74 from abrasion in actual operation.

  Next, the arrangement range of the refractory material 108 with respect to the nozzle head 70 will be described. As shown in FIG. 3, the refractory material 108 is disposed on the side facing the suit blower 80 in the circumferential direction of the inlet header 71 of the header 70. The refractory material 108 covers at least the connecting portion between the nozzle table 70 and the nozzle table 74 in the arranged region. That is, the refractory material 108 covers a connection portion between a part of the nozzle pedestal 74 and the header pedestal 70 among the connection portions between the header 70 and the nozzle pedestal 74. The refractory material 108 of the present embodiment is arranged so as to include the entire injection range 150, which is the range in which the steam injected from the suit blower 80 is injected, in the circumferential direction of the inlet header 71. The refractory material 108 only needs to be disposed in a region including the injection range 150, and may be disposed in a region wider than a region included in the injection range 150. In other words, the refractory material 108 is arranged in the range of the angle θ from the axial center of the inlet header 71 in the circumferential direction of the inlet header 71. Here, in the range of the angle θ, the position of the surface of the inlet header 71 in contact with the line connecting the portion of the suit blower 80 that injects the steam and the axis of the inlet header 71, in other words, the suit blower 80 of the inlet header 71. And the closest distance.

  As described above, the nozzle protecting structure 90 has the strip 102 to which the Y-shaped anchor stud 104 is fixed arranged around the inlet header 71 and the fireproof material 108 is provided in the area where the Y-shaped anchor stud 104 is arranged. ing. As a result, the periphery of the nozzle 74 connected to the inlet header 71 can be covered with the refractory material 108, and the risk of wear on the nozzle 74 having a small thickness reduction margin can be reduced. In particular, when the wear prevention plate 96 is installed as in the present embodiment, a gap 99 generated near the connection portion between the inlet header 71 and the nozzle stand 74 of the header nozzle 70 that cannot be blocked by the wear prevention plate 96 is provided. It can be protected with a refractory material 108. Thereby, wear of the nozzle 74 in the region of the gap 99 can be suppressed. Furthermore, in areas where the gap 99 is narrow during maintenance, it is not necessary to manage the wall thickness of the nozzle 74, which has been difficult to manage due to the difficulty of measurement by a UT wall thickness inspection device, etc., and maintenance is easy. become.

  The nozzle protection structure 90 is provided with a strip 102 on the outer periphery of the inlet header 71 of the header 70, and a refractory material 108 is provided on the strip 102 using a Y-shaped anchor stud 104 or the like. Thus, even when the temperature rises due to the strip 102 and a temperature difference occurs between the inlet header 71 and the mutual positional relationship is displaced due to the difference in thermal expansion, it is possible to suppress the load on the refractory material 108. In other words, by providing the strip 102, the load on the refractory material 108 can be made smaller than when the refractory material 108 is provided directly on the inlet header 71, so that the refractory material 108 is prevented from being damaged and falling off. it can.

  The nozzle protection structure 90 is provided with a plurality of Y-shaped anchor studs 104 on the band plate 102 so that the Y-shaped anchor studs 104 can hold the refractory material 108 in the region where the band plate 102 is disposed. The material 108 can be made difficult to fall off. Further, the Y-shaped anchor stud 104 can be more securely held by the Y-shaped anchor stud 104 by changing the orientation of the surface of the Y-shaped anchor stud 104 with respect to the longitudinal direction of the strip plate 102 depending on the arrangement position. it can. In the present embodiment, the Y-shaped anchor stud 104 is used because the refractory material 108 can be more stably held with a simple shape. However, the refractory material holding metal fitting installed on the band plate 102 is not limited thereto. The refractory material holding metal fitting only needs to be able to hold the refractory material 108 around the band plate 102. For example, the tip may be divided into three or more, or one rod-shaped member may be curved.

  In addition, by fixing the Y-shaped anchor stud 104 to the band plate 102, heat conduction between the Y-shaped anchor stud 104 and the header nozzle 70 can be reduced. If the Y-shaped anchor stud 104 is directly fixed to the inlet header 71 of the nozzle head 70, the Y-shaped anchor stud 104 is partially removed from the strip 102 by the combustion gas flowing through the combustion gas passage 60. And a state in which a part of the Y-shaped anchor stud 104, in particular, the base 134 portion for fixing and supporting the Y-shaped anchor stud 104 is reduced in temperature by a heating medium such as boiler feed water and steam flowing through the header 70. Thus, a temperature difference may occur in the vicinity of the base 134 of the Y-shaped anchor stud 104, and thermal fatigue due to the temperature difference may occur and break. In this embodiment, the Y-shaped anchor stud 104 is fixed to the base plate 102 by the base 134, so that the vicinity of the base 134 is suppressed from being reduced in temperature, and the occurrence of thermal fatigue due to the temperature difference can be suppressed and damaged. Can be suppressed. As described above, by providing the Y-shaped anchor stud 104 on the strip 102 installed on the outer periphery of the inlet header 71 of the header 70, the base corresponding to the root of the Y-shaped anchor stud 104 when the boiler is stopped. Since the temperature difference in 134 is not affected by thermal fatigue, which is a concern, the durability of the nozzle protection structure 90 can be increased.

  By providing the electrolytic lath 106, the nozzle protection structure 90 can hold the refractory material 108 more reliably around the header nozzle 70 and can prevent the refractory material 108 from falling off. In addition, when the refractory material 108 is placed, it is possible to easily hold the refractory material 108 before solidifying around the header nozzle 70, and to make the shape of the refractory material 108 a desired shape. If the refractory material unit 94 is a small size, the electrolytic lath 106 may be omitted.

  In addition, the nozzle protection structure 90 installs the refractory material 108 by making the refractory material 108 not a whole circumference of the inlet header 71 but a part of the circumferential direction that requires countermeasures against wear on the header nozzle. The increase of the weight by this can be suppressed, and the increase in the load concerning the support structure of the inlet header 71 provided in the combustion gas passage can be suppressed.

  Further, the nozzle protection structure 90 is an upstream region in the steam flow direction in the circumferential direction of the inlet header 71 in the flow direction of the steam (gas, gas) injected by the suit blower 80 as an injection device. It is preferable to provide the refractory material 108 in a part including By providing the refractory material 108 in a part including the region upstream of the steam flow direction, a portion where the steam that causes wear on the nozzle 74 can be sprayed on the nozzle 74 is protected by the refractory 108. can do. Thereby, generation | occurrence | production of abrasion of the nozzle 74 can be suppressed.

  Further, the nozzle protection structure 90 is a part of the peripheral side of the inlet header 71 on the side where the suit blower 80 as an injection device is provided, specifically, the distance from the suit blower 80 of the inlet header 71 is the longest. By providing the refractory material 108 in a range including a close position, the nozzle 74 is worn by the steam injected from the suit blower 80, the combustion ash being caught in the injected steam, and the combustion ash sprayed with the steam. Can be suppressed.

  It is preferable that the refractory material 108 covers the entire range of the outer surface of the inlet header 71 that is not obstructed by other members and can be connected to the injection position of the suit blower 80 in a straight line. By covering the entire range in which the steam is injected from the suit blower 80 with the refractory material 108, it is possible to suppress the nozzle 74 from being worn by the influence of the steam injected from the suit blower 80.

  Here, the angle θ around the axis of the inlet header 71 on which the refractory material 108 is provided is preferably 45 ° or more and 180 ° or less, and more preferably 60 ° or more and 180 ° or less. By setting the angle θ at which the refractory material 108 is provided to be 45 ° or more, preferably 60 ° or more, it is possible to protect a region that is easily worn by the steam sprayed from the suit blower 80. By setting the angle range in which the refractory material 108 is provided to be 180 ° or less, the weight of the refractory material 108 can be increased while sufficiently suppressing the wear of the refractory material 108 with respect to the spray range of the steam sprayed from the suit blower 80. Can be suppressed.

  Since the plate unit 92 can be moved in accordance with deformation of the nozzle pedestal 74 by fixing the wear preventing plate 96 to the nozzle pedestal 74 by the fixing portion 98, the wear preventing plate 96 and the nozzle pedestal 74 can be prevented from being loaded. That is, when the wear prevention plate 96 is fixed to the inlet header 71, the nozzle 74 is deformed and a load is applied to the wear prevention plate 96 and the nozzle 74. However, the load is prevented by not fixing the wear prevention plate 96 to the inlet header 71. This can be suppressed. Further, by providing the refractory material 108, it is possible to prevent the nozzle 74 from being exposed and worn at the gap 99.

  The refractory material 108 is divided into a plurality of refractory material blocks 108a, and a gap 142 is provided, so that a thermal expansion difference due to a temperature difference occurs between the header nozzle 70 and the refractory material 108, and the refractory material 108 and the like. Even if the mutual positional relationship fluctuates, the influence due to the difference in elongation can be suppressed for each refractory material block 108a. Thereby, it can suppress that a load concentrates on a part of refractory material 108, and can suppress damage and omission of the refractory material 108.

  Next, the arrangement | positioning area | region of the refractory material 108 of the nozzle protection structure 90 is demonstrated using FIGS. 9-11. FIG. 9 is a schematic diagram showing the relationship between the inlet header 71 and the suit blower 80, and the nozzle 74 is omitted. 10 is a cross-sectional view taken along line AA in FIG. 11 is a cross-sectional view taken along line BB in FIG. As shown in FIGS. 9 to 11, the nozzle protecting structure 90 may adjust the range in which the refractory material 108 is arranged in accordance with the arrangement position of the suit blower that causes wear of the nozzle. .

  As shown in FIGS. 9 to 11, the nozzle protection structure 90 includes a header nozzle in which the refractory material 108 is disposed in a region where the suit blower 80 is arranged to face in the axial direction of the header header 70. When the angle around the axis of 70 is θa, and the angle around the axis of the header 70 where the refractory material 108 in the area where the suit blower 80 is not arranged is opposed is θb, θa > Θb. That is, the angle of the refractory material in the region where the suit blower 80 is not disposed facing may be smaller than the angle of the refractory material 108 in the region where the suit blower 80 is disposed facing. Thereby, the quantity of the refractory material 108 can be decreased.

  Further, the nozzle protection structure 90 may have different ranges in which the refractory material 108 is disposed corresponding to the position of the nozzle 74 connected to the inlet header 71. Specifically, if the thickness of the inlet header 71 has a sufficient margin for thinning due to wear, the region where the nozzle 74 to be protected is not disposed is a gas (vapor) that is worn by a suit blower or the like. The refractory material 108 may not be disposed even in the range in which) is supplied.

  Moreover, although this embodiment demonstrated the case where the inlet header 71 was used as the header nozzle, it can apply to the various header nozzles arrange | positioned in the combustion gas channel | path 60 through which combustion gas flows. Further, in the present embodiment, the case where the cause of causing wear on the nozzle is steam sprayed from the suit blower 80 has been described. However, the nozzle protection structure 90 of the present embodiment causes wear on the nozzle. It can be installed for various causes. For example, when the combustion ash moving with the combustion gas is a cause of wear, the refractory material 108 may be disposed upstream of the nozzle in the combustion gas flow direction. As described above, when the other fluid flowing through the combustion gas passage 60 becomes a gas that causes wear on the nozzle 74, a part of the region on the upstream side in the flow direction of the other fluid in the circumferential direction of the inlet header 71. By providing the refractory material 108 only, the occurrence of wear of the nozzle 74 can be suppressed while suppressing an increase in the weight of the nozzle protection structure 90.

  Next, a manufacturing method of the nozzle protecting structure 90 will be described with reference to FIG. FIG. 12 is a flowchart showing an example of a manufacturing method of the nozzle protection structure. The process shown in FIG. 12 can be realized by being executed by an operator. The worker first manufactures the header nozzle 70 from the inlet header 71 and the nozzle 74 (step S12). As a result, the header nozzle 70 to which the nozzle 74 is fixed is manufactured.

  Next, the worker manufactures the band plate 102 and attaches the Y-shaped anchor stud 104 to the band plate 102 (step S14). For example, an operator cuts a board into predetermined width and length, and manufactures the elongate board used as the strip board 102. FIG. Thereafter, the Y-shaped anchor stud 104 is attached by welding or the like to a position where the refractory material 108 is installed, except in a region to be the welded portion 116. As a result, a band plate to which a plurality of Y-shaped anchor studs 104 are attached is manufactured. The band plate 102 may be manufactured separately or together with the axial plate 112 and the circumferential plate 114. Moreover, the width | variety or length may change the strip 102 depending on the installation position of the header 70, and the longitudinal direction of the strip 102 of the surface used as the arrangement position of the Y-shaped anchor stud 104 or a Y-shape You may change the direction to. The operation in step S12 and the operation in step S14 can be performed in parallel. Moreover, you may perform the operation | work of step S12 and the operation | movement of step S14 in a place different from the place where the boiler is installed, for example, a production factory.

  Next, an operator installs the strip 102 around the header nozzle 70 (step S16). Specifically, the strips 102, for example, the end and end of one circumferential plate 114, and the overlapping portion of the circumferential plate 114 and the axial plate 112 are fixed by welding or the like. Thereby, the strip 102 including the plurality of axial plates 112 and the circumferential plates 114 is arranged around the inlet header 71 of the header header 70 so as to be movable to the header header 70. be able to. That is, the band plate 102 can be installed on the outer periphery of the inlet header 71. The band plate 102 is disposed between the nozzles 74 of the header nozzle 70. For this reason, the movable range of the band plate 102 is a part between the nozzles 74.

  The operator installs the electrolysis lath 106 around the Y-shaped anchor stud 104 after installing the strip 102 on the header 70 (step S18). That is, the electromelting lath 106 is hung on the region where the Y-shaped anchor stud 104 is disposed. The electroweld lath 106 may be hung on the branch portion 132 of the Y-shaped anchor stud 104 or may be non-contact.

  After installing the electrofused lath 106, the worker installs the refractory material 108 (step S20), and dries the refractory material 108 (step S22). Specifically, the worker applies the refractory material 108 toward the target region of the header nozzle 70 on which the strip plate 102, the Y-shaped anchor stud 104, and the electroformed lath 106 are arranged. The refractory material 108 supplied to the region where the Y-shaped anchor stud 104 and the electromelting lath 106 are disposed is entangled with the Y-shaped anchor stud 104 and the electromelting lath 106, and the Y-shaped anchor stud 104 and the electromelting lath 106 are disposed. Stay in the area. The refractory material 108 is fixed around the nozzle to be protected by being dried while remaining in the region where the Y-shaped anchor stud 104 and the electromelting lath 106 are disposed.

  As shown in FIG. 12, the manufacturing method of the nozzle protecting structure 90 is capable of manufacturing a nozzle protecting structure that mainly protects the nozzle by performing work, and a header having the nozzle protecting structure. Stands and nozzles can be manufactured. In addition, a part in which the Y-shaped anchor stud 104 is attached to the band plate 102 is manufactured in advance, and the part is installed on the header nozzle 70, thereby reducing the work around the header header 70. it can. Thereby, a nozzle protection structure can be installed efficiently.

  In addition, by installing the refractory material 108 after the Y-shaped anchor stud 104 is installed, the refractory material 108 becomes difficult to peel off from the periphery of the header nozzle 70. Thereby, durability of the nozzle stub protection structure 90 can be increased, and the possibility of occurrence of wear of the nozzle stub 74 can be reduced.

  In the process shown in FIG. 12, the nozzle 74 and the header nozzle 70 are manufactured. However, the manufacturing method of the nozzle protection structure is already manufactured and the nozzle 74 and the header nozzle 70 installed in the boiler. May be installed against.

  Further, it is further preferable that the nozzle protection structure 90 is configured such that the plate unit 92 is installed on the nozzle pedestal 74 when the header header 70 is manufactured from the inlet header 71 and the nozzle pedestal 74. By installing the plate unit 92 in addition to the refractory material unit 94 including the refractory material, it is possible to manufacture a structure in which the nozzle 74 is not easily worn.

  In the above-described embodiment, the boiler according to the present invention is a coal-fired boiler. However, the solid fuel may be a boiler using biomass, petroleum coke, petroleum residue, or the like. Further, the fuel can be used not only for solid fuel but also for oil-fired boilers such as heavy oil, and further, gas (by-product gas) can also be used as fuel. And it can apply also to the mixed combustion sowing of these fuels.

10 Coal-fired boiler (boiler)
DESCRIPTION OF SYMBOLS 11 Furnace 12 Combustion apparatus 13 Flue 21, 22, 23, 24, 25 Combustion burner 41, 42, 43 Superheater (heat exchanger)
44 Second reheater (heat exchanger)
45 First reheater (heat exchanger)
46 Second economizer (heat exchanger)
47 First economizer (heat exchanger)
60 Combustion gas passage 61 Steam turbine 65 Inlet header 67 Intermediate header 68 Outlet header 70 Pipe header 71 Inlet header (heading)
72 Intermediate header 73 Outlet header 74 Tubular head 75 Heat transfer tube 80 Suit blower (injection device)
90 Base protection structure 92 Plate unit 94 Refractory material unit 96 Abrasion prevention plate 98 Fixing part 99 Clearance 102 Band plate 104 Y-shaped anchor stud (refractory material support bracket)
106 Electrolytic lath 108 Refractory material 112 Axial plate 114 Circumferential plate 116 Welded part 130 Straight line part 132 Branch part 134 Base 142 Gap 150 Injection range

Claims (9)

A nozzle protection structure that is provided in a combustion gas passage through which combustion gas generated by burning fuel flows and that is installed in a header nozzle including a header and a nozzle attached to the header. And
A plurality of strips installed on the outer periphery of the header,
A plurality of refractory support brackets fixed to the strip,
A refractory material supported by the refractory support bracket and covering at least a connecting portion of the nozzle with the header;   2. The refractory material is disposed only in a part including a region on an upstream side in a flow direction of a gas that generates wear of the nozzle pedestal in a circumferential direction of the header nozzle. A nozzle protection structure as described in 1. The gas that causes abrasion of the nozzle is a jet gas from a jet device,
The said refractory material is arrange | positioned in the range of 45 degrees or more and 180 degrees or less of the circumferential direction centering on the shaft center of the said nozzle head, The nozzle protection structure of Claim 2 characterized by the above-mentioned. Having an anti-abrasion plate supported on at least a portion of the nozzle,
The said refractory material is arrange | positioned in the range containing the clearance gap formed between the said abrasion prevention board and the said header, The nozzle protection as described in any one of Claim 1 to 3 characterized by the above-mentioned. Construction.   5. The refractory material support fitting according to claim 1, wherein one end of a bar is fixed to the band plate, and the other end of the bar branches into two. 5. Described nozzle protection structure. An injection device for injecting gas toward the header nozzle at a position facing the header nozzle;
The gas that causes abrasion of the nozzle is a gas to be injected from the injection device,
The said refractory material is arrange | positioned in the range including the position where the distance with the said injection apparatus of the said header is the shortest, The nozzle protection structure as described in any one of Claim 1 to 5 characterized by the above-mentioned.   The said refractory material covers the range including the range which can be tied with the injection position of the said injection apparatus without being interrupted by other members among the outer surfaces of the said header. Tubular protection structure. A combustion gas passage through which the combustion gas flows;
A header head including a header installed in the combustion gas passage and a plurality of nozzles connected to the header;
A boiler having a nozzle protection structure according to any one of claims 1 to 7, which is installed in the nozzle head. For a header head having a header and a plurality of nozzles attached to the header in a combustion gas passage through which combustion gas generated by burning fuel flows.
Installing a refractory support bracket on a plurality of strips;
Installing the strip on which the refractory support metal fitting is installed in the header nozzle;
Applying a refractory material to the strip,
The said refractory material is arrange | positioned only in a part including the area | region of the upstream of the direction through which the gas which generate | occur | produces abrasion of the said nozzle nozzle flows in the circumferential direction of the said nozzle header. Manufacturing method.

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