JP2020125858A - Heat exchanger, boiler, and heat absorbing amount adjusting method of heat exchanger - Google Patents

Abstract

To easily adjust an area in which a drift plate is attached, and to suitably suppress the drift of combustion gas.SOLUTION: A superheater 42 includes a plurality of heat transfer pipes 43 heat-exchanging between supply water flowing in an inside thereof and combustion gas generated in a furnace and extending in a vertical direction, and a drift plate 81 detachably fixed with respect to the heat transfer pipe 43. The heat transfer pipes 43 are arranged side by side in a flow direction of the combustion gas, and are arranged side by side in a width direction of a flue 13. The drift plate 81 is fixed by the heat transfer pipe 43 disposed in a downstream side end of the flow direction of the combustion gas, and is arranged so that a plate surface crosses the flow direction of the combustion gas.SELECTED DRAWING: Figure 3

Description

The present invention relates to a heat exchanger, a boiler, and a heat absorption amount adjusting method for the heat exchanger.

A large-scale boiler such as an oil-fired boiler has a furnace that has a hollow shape and is installed in the vertical direction, and a plurality of combustion burners are arranged on the furnace wall along the circumferential direction of the furnace. Further, in the oil-fired boiler, a flue is connected vertically above the furnace, and a heat exchanger for generating steam is arranged in the flue. Then, the combustion burner injects fuel and air into the furnace to form a flame, and combustion gas is generated and flows into the flue. A heat exchanger is installed in a region where the combustion gas flows, and superheated steam is generated by heating water or steam flowing in the heat transfer tube that constitutes the heat exchanger.

In such a boiler, the distribution of the gas flow passing through the heat exchanger may be changed by disposing a drift member that changes the gas flow in the flue (for example, Patent Document 1). In the apparatus of Patent Document 1, a large amount of CO flowing near the ceiling wall is provided by installing a protrusion on the ceiling of the auxiliary side wall that forms the flow path of the furnace outlet so as to project inside the auxiliary side wall. The combustion gas is made to flow toward the center of the sub side wall.

JP, 2010-71597, A

By the way, in the flue gas of the boiler through which the combustion gas flows, a drift of the combustion gas may occur due to the shape of the wall surface, the shape and arrangement of the heat exchanger, the short path, and the like.
Moreover, the heat exchanger (for example, a superheater etc.) arrange|positioned in a flue is comprised by many heat transfer tubes. The combustion gas circulates in the flue when the combustion gas passes through the gap formed between the adjacent heat transfer tubes. Since the combustion gas contains various components, a viscous clinker or the like may adhere to the surface of the heat transfer tube which comes into contact with the combustion gas. When a viscous clinker or the like adheres, the length of the gap between the adjacent heat transfer tubes changes, so the flow rate and flow velocity of the combustion gas passing through each gap differ depending on the presence or absence of the viscous clinker and the amount of adhesion. Therefore, due to such a factor, uneven distribution of the combustion gas may occur and the distribution of the gas flow passing through the heat exchanger may change.

When the drift of the combustion gas occurs, a difference in the amount of heat absorbed from the combustion gas occurs in each heat transfer tube, resulting in an uneven temperature distribution. For this reason, in a heat transfer tube having a large amount of heat absorption, the temperature (metal temperature) locally rises, and there is a risk that the temperature will exceed the allowable temperature and damage.

In order to prevent the local temperature rise of the heat transfer tube, for example, it is conceivable to provide the protrusion described in Patent Document 1 to change the flow of the combustion gas and suppress the uneven flow of the combustion gas. However, Patent Document 1 does not consider the fixing mode of the protrusions. For example, in the device of Patent Document 1, when the protrusion is fixed by welding or the like, the protrusion cannot be easily removed. Therefore, for example, when the uneven flow of the combustion gas cannot be suitably suppressed even if the protrusion is attached, or the state of the boiler after the protrusion is attached (for example, the viscous clinker attached to the surface of the heat transfer tube) Change and the drift of the combustion gas changes, there is a possibility that the mounting position cannot be easily changed even if the position of the attached protrusion is to be changed. As a result, it may not be possible to suitably suppress the uneven flow of the combustion gas.

The present invention has been made in view of such circumstances, and a heat exchanger and a boiler capable of easily adjusting a region to which a deflector plate is attached and capable of suppressing the deflected flow of high-temperature gas. Moreover, it aims at providing the heat absorption amount adjustment method of a heat exchanger.

In order to solve the above problems, the heat exchanger, the boiler, and the heat absorption amount adjusting method for the heat exchanger of the present invention employ the following means.
A heat exchanger according to an aspect of the present invention has a fluid flowing therein, heat-exchanges a high-temperature gas having a temperature higher than that of the fluid with the fluid, and a predetermined direction intersecting a flow direction of the high-temperature gas. A plurality of heat transfer tubes, and a deflector plate detachably fixed to the heat transfer tubes, wherein the plurality of heat transfer tubes are arranged side by side in the flow direction of the high temperature gas, and Arranged side by side in an intersecting direction that intersects both the gas flow direction and the predetermined direction, the flow diverter plate is fixed to the heat transfer tube arranged at a downstream end in the flow direction of the high temperature gas. Thus, the plate surface is provided so as to intersect the flow direction of the high temperature gas.

In the above configuration, the deflector plate is provided so that the plate surface intersects the flow direction of the high temperature gas with respect to the heat transfer tube that exchanges heat between the high temperature gas and the fluid. That is, a part of the flow of the high temperature gas is obstructed by the drift plate. As a result, the hot gas flows so as to avoid the drift plate. Therefore, the flow of the high temperature gas can be changed by providing the deflector plate. Therefore, it is possible to reduce the flow rate of the high-temperature gas in the region where the deflector plate is provided. Therefore, for example, in a flow path through which the high temperature gas flows, when a deviation in the flow rate of the high temperature gas occurs, by providing a deflector plate in a region where the flow rate of the high temperature gas is high, the flow rate of the high temperature gas in the region is increased. It can be reduced. Therefore, it is possible to suppress the deviation of the high temperature gas flow rate. Therefore, the amount of heat absorbed by the fluid flowing in the heat transfer tube is adjusted, and local temperature rise of the heat transfer tube due to uneven flow rate of the high temperature gas is suppressed. Therefore, it is possible to suppress damage to the heat transfer tube and decrease in heat transfer performance.

Moreover, since the deflector plate is detachably fixed, the deflector plate can be removed from the heat transfer tube. That is, the deflector plate can be removed while maintaining the function of the heat transfer tube. As a result, it is possible to easily change and adjust the area to which the deflector plate is attached. Therefore, even if the deflector plate is provided in a region where it is not necessary to suitably suppress the bias of the high temperature gas flow rate, the position where the deflector plate is attached can be easily changed. Further, even if the condition of the high temperature gas flow changes after attaching the deflector plate and the region where the flow rate of the high temperature gas is high changes, the deflector plate can be installed again in the region where the flow rate of the high temperature gas is high. .. In this way, since the mounting region of the deflector plate can be easily adjusted, the deflector plate can be installed more suitably in the region where the flow rate of the high temperature gas is high. Thereby, the flow rate of the high temperature gas in the region can be reduced more preferably. Therefore, the deviation of the high temperature gas flow rate can be suppressed more suitably. Therefore, the amount of heat absorbed by the fluid flowing in the heat transfer tube is adjusted more appropriately, and the local temperature rise of the heat transfer tube due to the uneven flow rate of the high-temperature gas is more preferably suppressed. Therefore, damage to the heat transfer tube and reduction in heat transfer performance can be suppressed more favorably.

In addition, since the deflector plate is removable, if a local temperature rise in the heat transfer tube suddenly occurs due to an uneven flow rate of the high-temperature gas, a temporary local measure must be taken before permanent measures are taken. The temperature rise can be suppressed. That is, when the deflector plate is not required for the permanent measure, the deflector plate can be easily removed and the permanent measure can be implemented.
Further, when the deflector plate is temporarily attached and the effect thereof is confirmed, it is possible to limit the area in which the countermeasure needs to be implemented and then implement the permanent countermeasure.

Further, the drift plate is fixed to the heat transfer tube arranged at the downstream end. As a result, the high-temperature gas that collides with the deflector plate becomes the high-temperature gas that has completed heat exchange with the heat transfer tube on the upstream side. Therefore, the temperature of the high temperature gas that collides with the deflector plate is lower than that when the deflector plate is fixed to the upstream heat transfer tube. Therefore, it is possible to suppress damage to the drift plate due to heat.

Further, in the heat exchanger according to one aspect of the present invention, a plurality of the deflector plates are provided, and the plurality of the deflector plates are arranged such that the plate surface is along the surface formed in the predetermined direction and the intersecting direction. They may be arranged side by side.

The deflector plates are provided with a plurality of deflector plates, and the deflector plates are arranged side by side along a surface formed in the predetermined direction and the intersecting direction. That is, the plurality of deflector plates obstruct the high temperature gas passage. As a result, compared to the case where the same area is obstructed, it is possible to reduce the size of each of the deflector plates, as compared with the case where the one deflector plate is used. Therefore, it is possible to improve workability in the work of attaching and removing the deflector plate.
Further, since a plurality of detachable deflector plates are provided, it is possible to adjust the blocking area of the flow path through which the high temperature gas flows by attaching or detaching each deflector plate. Therefore, the flow rate of the high temperature gas can be accurately reduced, so that the deviation of the flow rate of the gas in the high temperature gas passage can be suppressed.

Further, in the heat exchanger according to the aspect of the present invention, the plurality of the drift plates may be arranged side by side along a predetermined direction.

In the above configuration, the flow diverter plates are arranged side by side along the predetermined direction. By this, by attaching and detaching the deflector plate, it is possible to adjust the inhibition region of the high temperature gas flow path due to the deflector plate in the predetermined direction. Therefore, even if there is a deviation in the hot gas flow rate in the predetermined direction in the hot gas flow path, it is possible to suppress the deviation in the gas flow rate in the hot gas flow path.

Further, in the heat exchanger according to the aspect of the present invention, an elliptical bolt hole is formed in the drift plate, and the drift plate and the heat transfer tube are U-bolts inserted through the bolt hole. May be fixed by.

In the above-described configuration, the drift plate is detachably fixed to the heat transfer tube by the U bolt that is inserted through the oval bolt hole. As a result, even if the deflector plate thermally expands in the longitudinal direction of the oval shape, it is possible to suppress the interference between the U bolt and the edge of the bolt hole. Therefore, it is possible to suppress damage to the U-bolts and bolt holes, and deformation/damage to the drift plate and the heat transfer tubes. The longitudinal direction of the oval shape is preferably the intersecting direction.

Further, in the heat exchanger according to one aspect of the present invention, the deflector plate is a bent portion that extends from an end portion of the plate surface in the intersecting direction by bending to an upstream side or a downstream side direction in a flow direction of the high temperature gas. May have.

In the above configuration, the end portion of the deflector plate in the intersecting direction of the plate surface is bent. Thereby, the rigidity of the drift plate can be improved. Therefore, even when the deflector plate is made of a plate material, the deformation can be suppressed. Further, even if the end portion of the deflector plate comes into contact with the adjacent heat transfer tube due to vibration of the deflector plate or the like, the end portion of the deflector plate and the heat transfer tube make surface contact, so Damage can be suppressed.

A boiler according to an aspect of the present invention includes the heat exchanger according to any one of the above, and a combustion gas passage through which a combustion gas generated in a furnace flows, wherein the heat exchanger includes the combustion gas flow. Provided in the passage, the hot gas is the combustion gas.

In the boiler according to the aspect of the present invention, the heat exchanger may be a superheater.
In the above configuration, since the superheater is a heat exchanger arranged near the connecting position where the combustion gas flow direction of the flue changes from the vertical direction to the horizontal direction, the flow of the combustion gas is more likely to flow in the inner peripheral side than in the outer peripheral side. It is easily affected by uneven flow such as easy flow. Therefore, by providing the deflector plate in the superheater, the deflector plate can be installed in a region where the flow rate of the combustion gas is high. As a result, the local temperature rise of the heat transfer tube due to the uneven flow rate of the combustion gas is further suppressed, so that damage to the heat transfer tube and deterioration of the heat transfer performance can be suppressed.

The heat absorption amount adjusting method for a heat exchanger according to an aspect of the present invention is such that the heat exchanger has a fluid flowing therein, and heat-exchanges a hot gas having a temperature higher than that of the fluid with the fluid, A plurality of heat transfer tubes extending in a predetermined direction intersecting the flow direction of the high-temperature gas, and a deflector plate detachably fixed to the heat transfer tubes, wherein the plurality of heat-transfer tubes flow the high-temperature gas. Are arranged side by side in a direction, and are arranged side by side in an intersecting direction that intersects both the flow direction of the high temperature gas and the predetermined direction, and the drift plate is a downstream end portion in the flow direction of the high temperature gas. Is fixed to the heat transfer tube arranged in the above, the plate surface is provided so as to intersect with the flow direction of the high temperature gas, and the step of changing the flow of the high temperature gas by the deflector plate is provided. ..

According to the present invention, it is possible to easily adjust the region to which the deflector plate is attached, and it is possible to preferably suppress the deflected flow of the high-temperature gas.

It is a schematic structure figure showing an oil fired boiler concerning an embodiment of the present invention. It is the schematic which shows the heat exchanger provided in the oil-fired boiler of FIG. 1, and a steam and water supply system. It is a side view which shows the superheater of FIG. FIG. 4 is a sectional view taken along the line BB of FIG. 3. It is a top view of the superheater of FIG. It is a development view of the deflector plate of FIG. FIG. 4 is a perspective view showing the deflector plate of FIG. 3. It is a figure which shows the modification of FIG.

Preferred embodiments of the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to this embodiment, and when there are a plurality of embodiments, the present invention also includes those configured by combining the embodiments.

The boiler of the present embodiment uses heavy oil or crude oil as fuel (carbon-containing liquid fuel), burns this fuel with a combustion burner, recovers the heat generated by this combustion, and exchanges heat with feed water or steam to superheat it. It is an oil-fired boiler that can generate steam. In the following description, the upper side and the upper side refer to the upper side in the vertical direction, and the lower side and the lower side refer to the lower side in the vertical direction.

The boiler system 1 according to the present embodiment includes an oil-fired boiler 10, pumps 31 and 32 that supply fuel to the oil-fired boiler 10, and the like.

In the present embodiment, as shown in FIG. 1, the oil-fired boiler 10 has a furnace 11, a combustion device 12, and a flue (combustion gas passage) 13. The furnace 11 has a hollow rectangular tube shape and is installed along the vertical direction. The furnace wall that constitutes the furnace 11 is composed of a plurality of evaporation tubes and fins that connect them, and suppresses the temperature rise of the furnace wall by exchanging heat with the feed water and steam.

The combustion device 12 is provided on the lower side of the furnace wall forming 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. For example, the combustion burners 21, 22, 23, 24, 25 are arranged in a plurality of stages along the vertical direction, with one set of combustion burners 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.

Each combustion burner 21, 22, 23, 24, 25 is connected to a pump 31, 32 via a fuel supply pipe 26, 27, 28, 29, 30. Although not shown, the pumps 31 and 32 are connected to a fuel storage facility such as a fuel tank. Fuel can be supplied to the combustion burners 21, 22, 23, 24, 25 from the fuel storage facility via the fuel supply pipes 26, 27, 28, 29, 30 by the pumps 31, 32.

Further, in the furnace 11, a wind box 36 is provided at a 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. The air duct 37 is provided with a blower 38 at the other end.

The flue 13 is connected to a vertically upper portion of the furnace 11. The flue 13 is provided with superheaters 41 and 42, reheaters 44 and 45, and economizers 46 and 47 as heat exchangers for recovering heat of combustion gas (high temperature gas), and the furnace 11 The heat exchange is performed between the combustion gas generated by the combustion in the above and the feed water or steam which is the fluid flowing through each heat exchanger.

The flue 13 is connected to a gas duct 48 on the downstream side from which the combustion gas having undergone heat exchange is discharged. An air heater (air preheater) 49 is provided between the gas duct 48 and the air duct 37, heat is exchanged between the air flowing through the air duct 37 and the combustion gas flowing through the gas duct 48, and the combustion burners 21 and 22. , 23, 24, 25 can be heated.

Further, the gas duct 48 connected to the flue 13 has a chimney 53 at the downstream end.

On the other hand, when the pumps 31, 32 are driven, the fuel is supplied to the combustion burners 21, 22, 23, 24, 25 through the fuel supply pipes 26, 27, 28, 29, 30. Further, the heated combustion air is supplied from the air duct 37 to the respective combustion burners 21, 22, 23, 24, 25 via the wind box 36. Then, the combustion burners 21, 22, 23, 24, 25 blow a fuel into the furnace 11 and a combustion air into the furnace 11 by a nozzle (not shown), and at this time, a flame can be formed by igniting. A flame is generated in the lower part of the furnace 11, and the combustion gas rises in the furnace 11 and is discharged to the flue 13.

After that, the combustion gas exchanges heat with the superheaters 41 and 42, the reheaters 44 and 45, and the economizers 46 and 47 arranged in the flue 13, and then is discharged into the atmosphere from the chimney 53.

Next, the superheaters 41 and 42, the reheaters 44 and 45, and the economizers 46 and 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 the oil-fired boiler 10 and a steam and water supply system. In addition, in FIG. 2, it is a figure for demonstrating steam and a water supply system, and each heat exchanger (superheater 41,42, reheater 44,45, economizer 46,47) in the flue 13 is shown. It does not show the exact position.

As shown in FIG. 2, in the present embodiment, 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 and a reheater 44. , 45 and economizers 46, 47 are arranged. The superheaters 41 and 42 may be provided in series via a header, but the header is omitted in FIG.

The steam turbine 61 operated by the steam generated in the oil-fired boiler 10 is composed of, 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 be condensed water. The condenser 64 is connected to the inlet header 65 of the first economizer 47 via the water supply line L1. The inlet header 65 is provided in the combustion gas passage 60, and the water supply line L1 is provided with a water supply pump 66 outside the combustion gas passage 60. The second economizer 46 is arranged above the first economizer 47, and an intermediate header 67 is provided between the economizers 46, 47. An outlet header 68 is connected to an upper portion of the second economizer 46, and the outlet header 68 is arranged outside the combustion gas passage 60.

The outlet header 68 is connected to a steam drum 69 arranged outside the combustion gas passage 60 via a water supply line L2. The steam drum 69 is connected to each heat transfer pipe (not shown) on the furnace wall, and is also connected to the superheaters 41 and 42 via the inlet header 74. Further, the superheaters 41 and 42 are connected to the high pressure turbine 62 via the steam line L3. An exit header 75 is provided at L3. The high-pressure turbine 62 is connected to the inlet header (heading) 70 of the first reheater 45 via the steam line L4. The inlet header 70 is provided in the combustion gas passage 60, the first reheater 45 is connected to the second reheater 44 via the intermediate header 71, and the second reheater 44 has an outlet at the top. The header 72 is connected, and the intermediate header 71 and the outlet header 72 are arranged outside the combustion gas passage 60. The outlet header 72 is connected to the low pressure turbine 63 via the steam line L5 to drive the low pressure turbine 63 to rotate.

Therefore, when the combustion gas flows through the combustion gas passage 60 of the flue 13, the heat of the combustion gas is recovered in the order of the superheaters 41 and 42, the reheaters 44 and 45, and the economizers 46 and 47. On the other hand, the water supplied from the water supply pump 66 is preheated by the economizers 47 and 46, is then supplied to the steam drum 69, and is heated while being supplied to each heat transfer tube of the furnace wall (not shown) to be saturated steam. And returned to the steam drum 69. The saturated steam of the steam drum 69 is introduced into the superheaters 41 and 42 and superheated by the combustion gas. The superheated steam generated by the superheaters 41 and 42 is supplied to the high pressure turbine 62, and drives the high pressure turbine 62 to rotate. The steam discharged from the high-pressure turbine 62 is introduced into the reheaters 45 and 44 and is again superheated, and then is supplied to the low-pressure turbine 63 to rotate and drive the low-pressure turbine 63. A generator is connected to the rotating shaft of the steam turbine 61 to generate electricity. 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.

Further, in the flue 13, a suit blower (injection device) 80 may be arranged between the inlet header 70 and the economizer 47. The suit blower 80 extends in a direction parallel to the longitudinal direction of the inlet header 70 and is arranged at a position facing the inlet header 70. The suit blower 80 is an injection device that can inject steam (gas) in a direction orthogonal to the axial direction with the longitudinal direction of the inlet header 70 as the axial direction, and can also change the injection direction. The steam injected from the suit blower 80 toward the economizer 47 removes combustion ash accumulated on the surface of the heat transfer tube of the economizer 47.

Next, the superheater (heat exchanger) 42 provided in the flue 13 of the present embodiment and the deflector plate 81 provided in the superheater (heat exchanger) 42 will be described with reference to FIGS. 3 to 7. The details will be described. The superheater 42 is provided downstream of the superheater 41 in the flow of the combustion gas (high temperature gas). 3 to 5, the X direction indicates the flow direction of the combustion gas (high temperature gas) flowing through the flue 13. The Z direction (predetermined direction) indicates the vertical direction. Further, the Y direction (intersection direction) indicates a direction (in this embodiment, the width direction of the flue 13) orthogonal to both the X direction and the Z direction.

In order to explain the location of the superheater 42, first, the detailed shape of the flue 13 will be described. As shown in FIGS. 1 and 3, the flue 13 of the present embodiment is connected to an upper portion of the furnace 11 in the vertical direction and extends in a substantially vertical direction, and a top end of the first vertical portion 13a ( A horizontal portion 13b that bends from a downstream end in the combustion gas flow) and extends in a substantially horizontal direction and a second vertical portion 13c that extends substantially vertically downward from a downstream end of the horizontal portion 13b are integrally provided. A protruding portion 13d that protrudes into the combustion gas passage 60 is provided at an inner bent portion of a connecting portion between the first vertical portion 13a and the horizontal portion 13b. The protrusion 13d includes a first inclined surface 13da extending obliquely upward from the inner peripheral surface of the first vertical portion 13a, and a second inclined surface extending obliquely upward in the horizontal portion 13b direction from the upper edge of the first inclined surface 13da. 13 db, and the vertical cross section is formed in a substantially triangular shape.

In the present embodiment, the superheater 42 is arranged at the connecting portion between the first vertical portion 13a and the horizontal portion 13b. More specifically, it is provided above the protrusion 13d. The lower end of the superheater 42 is formed along the second inclined surface 13db. Further, the upstream end of the superheater 42 projects into the combustion gas passage 60 more than the tip of the projection 13d.

The superheater 42 includes a plurality of heat transfer tubes 43 that connect an inlet header 74 (see FIG. 4) extending in the width direction and an outlet header 75 extending in the same direction. As shown in FIG. 3, each heat transfer tube 43 has a first vertical tube portion 43a extending substantially vertically downward from the inlet header 74, and a second vertical surface 43db bent from the lower end of the first vertical tube portion 43a. An inclined pipe portion 43b extending obliquely downward and a second vertical pipe portion 43c bent from the lower end of the inclined pipe portion 43b and extending substantially vertically upward are provided. That is, the first vertical pipe portion 43a and the second vertical pipe portion 43c extend along the Z direction. Since the inlet header 74 and the outlet header 75 are provided outside the flue 13, the first vertical pipe portion 43a and the second vertical pipe portion 43c penetrate the ceiling wall 13e of the flue 13.

Further, the plurality of heat transfer tubes 43 of the superheater 42 are provided so as to be lined up at a predetermined interval along the Y direction (hereinafter, the Y direction is also referred to as “width direction”), and the first vertical pipe portion is provided. 43a and the 2nd vertical pipe part 43c are provided so that it may be located in a line with a predetermined interval along the X direction (henceforth the X direction is also called "flow direction of combustion gas.") (Drawing 4 and Drawing 5). reference).

Next, the deflector plate 81 will be described.
As shown in FIG. 3, the deflector plate 81 is a first vertical pipe of the heat transfer tubes 43 of the plurality of heat transfer tubes 43 of the superheater 42, which is arranged at the downstream end of the combustion gas in the flow direction (X direction). It is fixed to the portion 43a. Further, a plurality of deflector plates 81 are provided.

Each of the drift plates 81 is formed by bending a plate-shaped metal plate, as shown in FIGS. 6 and 7. The broken line portion in FIG. 6 is the bending position. A rectangular plate-shaped fixed portion 81a fixed to the heat transfer tube 43, an upper horizontal portion 81b bent from the upper end of the fixed portion 81a and extending substantially horizontally to the downstream side in the X direction, and bent from the lower end of the fixed portion 81a. A lower horizontal portion 81c that extends substantially horizontally to the downstream side in the X direction, an outer portion 81d that bends from the outer end of the fixed portion 81a (the wall side end of the flue 13) and extends to the downstream side in the X direction, and the fixed portion 81a. And an inner portion (bending portion) 81e that bends from the inner end of the and extends to the upstream side in the X direction. The drift plate 81 is arranged so that the plate surface of the fixed portion 81a is orthogonal to the X direction. The drift plate 81 is made of stainless steel such as SUS304, SUS316, or SUS310S, which has heat resistance and corrosion resistance. Since the combustion gas flows in the flue 13, for example, the ambient temperature is a high temperature atmosphere of about 800° C. to 1000° C., an oxidizing atmosphere, and a corrosive atmosphere. By forming the stainless steel having heat resistance and corrosion resistance, it is possible to suppress damage to the drift plate 81.

In the present embodiment, as shown in FIG. 6, the deflector plate 81 is formed by bending a single plate material. The present invention is not limited to this, and the drift plate 81 may be formed by connecting each part by welding or the like.
The plate thickness of each portion of the flow diverter plate 81 is set to, for example, about 4 mm to 8 mm, and the weight of the flow diverter plate 81 is set to, for example, about 10 kg to 20 kg. The plate thickness and weight of the deflector plate 81 are not limited to this. When installing and adjusting the flow diverting plate 81, it is preferable that the size and weight are such that it can be carried in and out from the manhole of the flue 13 or the like.

The fixing portion 81a is a plate member extending in the width direction and having a substantially rectangular shape in a front view, and is provided with a plurality of bolt holes 82 (six as an example in the present embodiment) penetrating in the plate thickness direction. The six bolt holes 82 are provided side by side at a predetermined interval in the width direction so that the drift plate 81 can be attached to, for example, the three heat transfer tubes 43 in the width direction (Y direction). Specifically, the first bolt hole 82a to the sixth bolt hole 82f are formed in order from the outer side 81d side. The 1st bolt hole 82a, the 2nd bolt hole 82b, the 5th bolt hole 82e, and the 6th bolt hole 82f are formed in the oval shape extended in the cross direction (it becomes the Y direction at the time of attachment). The third bolt hole 82c and the fourth bolt hole 82d are formed in a substantially perfect circular shape and enable positioning of the drift plate 81 with respect to the heat transfer tube 43. In addition, the number of the heat transfer tubes 43 at the time of attaching the non-uniform flow plate 81 in the width direction (Y direction) is not limited to three. For example, the number of the heat transfer tubes 43 may be set to one to five, and the bolt holes 82 may be provided side by side at a predetermined interval in the width direction.

The heat transfer tube 43 and the fixed portion 81a are provided with a plurality of U bolts 83 (three in this embodiment as an example) that are inserted through the bolt holes 82, and nuts (not shown) that are screwed into the shaft portions of the U bolts 83. It is fastened and fixed by. Specifically, the two shafts respectively insert the first U-bolt 83a through which the first bolt hole 82a and the second bolt hole 82b are inserted, and the two shafts respectively through the third bolt hole 82c and the fourth bolt hole 82d. The second U bolt 83b and the two shaft portions are fastened and fixed by the third U bolt 83c which passes through the fifth bolt hole 82e hole and the sixth bolt hole 82f, respectively. Each U-bolt 83 is provided such that the inner peripheral surface of the curved portion connecting the two shaft portions contacts the outer peripheral surface of the heat transfer tube 43. The first U bolt 83a, the second U bolt 83b, and the third U bolt 83c are detachably fixed to different heat transfer tubes 43.
Further, the U-bolt 83 and the nut screwed with each shaft portion of the U-bolt 83 have a high temperature atmosphere, an oxidizing atmosphere, and a corrosive atmosphere, similarly to the drift plate 81. 13 is provided. Therefore, the U-bolt 83 and the nut screwed with each shaft of the U-bolt 83 are made of stainless steel such as SUS304, SUS316, and SUS310S having heat resistance and corrosion resistance, like the drift plate 81. Thereby, damage to the U bolt 83 and the nut can be suppressed.

In this way, the heat transfer tube 43 and the drift plate 81 are detachably fixed. That is, it is not fixed by welding or the like at least until the attachment of the deflector plate 81 and the installation position thereof are taken as a permanent measure. As a result, the fixing of the heat transfer tube 43 and the deflector plate 81 can be released, and the attachment and detachment and the position can be adjusted without impairing the function of the heat transfer tube 43 or the deflector plate 81.

In the state where the heat transfer tube 43 and the fixed portion 81a are fixed, the inner portion (bent portion) 81e is located between the adjacent heat transfer tubes 43. The length of the inner portion 81e in the X direction is longer than the diameter of the heat transfer tube 43, and the end of the inner portion 81e in the X direction is connected to the heat transfer tube 43 on the upstream side of the heat transfer tube 43 to which the drift plate 81 is fixed. The length is set so that it does not touch.

As shown in FIGS. 3 and 4, the plurality of drift plates 81 are arranged side by side in the up-down direction (Z direction). Specifically, the fixing portions 81a are arranged side by side so that the plate surfaces of the fixing portions 81a are substantially flush with each other. That is, the plurality of deflector plates 81 are provided so as to obstruct the flow of the combustion gas in a partial region of the cross section of the flue 13. Specifically, as shown in FIG. 4, the flow diverter plate 81 allows the combustion gas to flow over substantially the entire area in the vertical direction in the regions at both ends in the width direction (Y direction) of the cross section of the flue 13. It is designed to block. Note that the area in which the flow diverting plate 81 is provided is an example, and is not limited to the area of the present embodiment. The region in which the non-uniform flow plate 81 is provided is provided in a region where the flow rate of the combustion gas is high and the temperature of the heat transfer tube 43 easily rises. That is, the region in which the deflector plate 81 is provided is a region determined to be a region where the flow rate of the combustion gas is high by simulation, test, or the like.

For example, in the width direction (Y direction) of the cross section of the flue 13, the flow of the combustion gas is obstructed with respect to the region of two or three heat transfer tubes 43 at one end of the flue 13. The drift plate 81 may be provided as described above. In addition, the deflector plate 81 is not provided in the area for one or two heat transfer tubes 43 at one end or both ends of the flue 13 and two heat transfer tubes 43 are provided in the adjacent area. A deflector plate 81 may be provided so as to obstruct the flow of the combustion gas in the area for three or three. In the up-down direction (Z direction), one to three deflector plates 81 may be provided at the upper end or the lower end of the flue so as to obstruct the flow of combustion gas. In addition, in the region of one to three sheets of the deflector plates 81 at the upper end portion or the lower end portion, the combustion gas is allowed to flow without providing the deflector plates 81, and the required number of deflector plates 81 are provided in the adjacent region. May be. In this way, the region where the plurality of deflector plates 81 are provided and which blocks the flow of the combustion gas can be freely set.

The plurality of flow diverting plates 81 may be provided so that the flow diverging plate 81 arranged at the lowermost stage is placed on the bottom surface portion of the flue 13, and an arbitrary distance from the bottom surface portion of the flue 13 may be provided. It may be set up. Further, the non-uniform flow plate 81 arranged in a position other than the lowermost stage may be provided so as to be mounted on the non-uniform flow plate 81 arranged below. Further, each of the drift plates 81 may be independently fixed to the heat transfer tube 43 by the fastening force of the U bolt 83 and the nut.

According to this embodiment, the following operational effects are exhibited.

In the present embodiment, a deflector plate 81 is provided inside the flue 13 such that the plate surface intersects the flow direction (X direction) of the combustion gas. That is, a part of the flow of the combustion gas in the flue 13 is obstructed by the uneven flow plate 81. As a result, the combustion gas flows so as to avoid the drift plate 81. Therefore, the flow of the combustion gas can be changed by providing the deflector plate 81. Therefore, the flow rate of the combustion gas in the region where the flow diverter plate 81 is provided can be reduced. Therefore, for example, when the flow rate of the combustion gas is uneven in the flue 13, the flow plate 81 is provided in a region where the flow rate of the combustion gas is high to reduce the flow rate of the combustion gas in the region. You can Therefore, the deviation of the gas flow rate in the flue 13 can be suppressed. Therefore, the amount of heat absorbed by the fluid (feed water or steam) flowing in the heat transfer tube 43 due to the deviation of the flow rate of the combustion gas is adjusted, and the local rise in the temperature of the heat transfer tube 43 (metal temperature) is suppressed. It is possible to suppress damage to the heat transfer tube 43 and performance deterioration.

In the present embodiment, as an example, the regions at both ends of the cross section of the flue 13 in the width direction are provided so as to obstruct the substantially entire region in the vertical direction. By providing in this way, it is possible to suppress the deviation of the gas flow rate of the flue 13 in the boiler in which the flow rate of the combustion gas is high in the regions at both ends in the width direction of the cross section of the flue 13.

The distribution of the flow rate of the combustion gas in the flue 13 is determined, for example, by the length of the gap between the heat transfer tubes 43 arranged in the width direction. That is, the pressure loss of the combustion gas flow is smaller and the flow rate of the combustion gas is higher in the region where the gap between the heat transfer tubes 43 is set wider than in the other regions than in the other regions. Therefore, the region in which the deflector plate 81 is provided may be determined based on the gap between the heat transfer tubes 43. Specifically, the drift plate 81 may be provided in the area where the heat transfer tubes 43 are provided so that the gap between the heat transfer tubes 43 is wider than the other areas.

Further, the non-uniform flow plate 81 and the heat transfer tube 43 are fixed by the U bolt 83 and the nut. That is, since the non-uniform flow plate 81 is detachably fixed, the non-uniform flow plate 81 can be removed from the heat transfer tube 43 or the installation position can be moved. As a result, it is possible to easily change the area in which the drift plate 81 is attached. Therefore, even if the drift plate 81 is provided at a position where the effect of suppressing the deviation of the flow rate of the combustion gas is small, the position where the drift plate 81 is attached can be easily changed. Further, even if the situation of the flow of the combustion gas changes after attaching the deflector plate 81 and the region of high flow rate of combustion gas changes, the deflector plate 81 should be installed again in the region of high flow rate of combustion gas. You can In this way, since the mounting region of the flow diverter plate 81 can be easily adjusted, the flow diverter plate 81 can be installed in a region where the flow rate of the combustion gas is high, more preferably. As a result, the amount of heat absorbed by the fluid flowing in the heat transfer tube 43 is adjusted, and the local temperature rise of the heat transfer tube 43 due to the uneven flow rate of the combustion gas is further suppressed. Can be suppressed.

Further, since the deflector plate 81 is detachable, when a local temperature rise of the heat transfer tube 43 due to an imbalance in the flow rate of the combustion gas suddenly occurs, a local emergency measure is taken before permanent measures are taken. Temperature rise can be suppressed. That is, when the deflector plate 81 is not required for the permanent measure, the deflector plate 81 can be easily removed and the permanent measure can be implemented.
Further, when the deflector plate 81 is temporarily attached and the effect thereof is confirmed, it is possible to limit the area in which the countermeasure needs to be implemented and then implement the permanent countermeasure.

The non-uniform flow plate 81 is fixed to the heat transfer tube 43 arranged on the most downstream side. As a result, the combustion gas that collides with the non-uniform flow plate 81 becomes the combustion gas that has finished heat exchange with the heat transfer tube 43 on the upstream side. Therefore, the temperature of the combustion gas that collides with the non-uniform flow plate 81 is lower than that in the case where the non-uniform flow plate 81 is fixed to the heat transfer tube 43 on the upstream side. Therefore, damage to the drift plate 81 due to heat can be suppressed.

A plurality of the non-uniform flow plates 81 are provided in the non-uniform flow plate 81, and the multiple non-uniform flow plates 81 are arranged side by side such that the plate surfaces thereof are flush with each other. That is, the flow of the combustion gas in the flue 13 is obstructed by the plurality of deflector plates 81. As a result, compared to the case where the same area is obstructed, each of the deflector plates 81 can be downsized as compared with the case where one deflector plate 81 is obstructed. Therefore, it is possible to improve the workability of the work of attaching and removing the deflector plate 81. In particular, since the inside of the flue 13 where the non-uniform flow plate 81 is attached is a narrow part, the non-uniform flow plate 81 can be carried in and out of the flue 13 from a manhole or the like by a worker without using a heavy machine or the like. The size and weight are preferably such that they can be carried. In the present embodiment, since the deflector plate 81 has a weight of about 10 to 20 kg that can be carried by a worker, workability can be improved.

Further, since a plurality of detachable deflector plates 81 are provided, the obstruction position and the obstruction area of the flue 13 can be finely adjusted by attaching or detaching each deflector plate 81. Therefore, the reduction amount of the combustion gas flow rate in each region of the cross section of the flue 13 can be adjusted, so that the deviation of the gas flow rate of the flue 13 can be appropriately suppressed.

Further, in the present embodiment, the drift plates 81 are arranged side by side along the up-down direction. By this, by attaching and detaching the deflector plate 81, the obstruction region of the flue 13 due to the deflector plate 81 can be adjusted in the vertical direction. Therefore, even if the combustion gas flow rate deviation occurs in the vertical direction in the flue 13, the deviation of the gas flow rate in the flue 13 can be suppressed.
Specifically, like the boiler 10 according to the present embodiment, when the flue 13 has the first vertical portion 13a and the horizontal portion 13b, the first vertical portion 13a and the horizontal portion 13b. Combustion gas may short-pass in the connection portion with. When the combustion gas short-passes, the flow rate of the combustion gas flowing on the inner peripheral side (arrow A in FIG. 3) tends to be higher than the flow rate of the combustion gas flowing on the outer peripheral side (arrow B in FIG. 3). In this way, the superheater 42 is disposed near the connecting position where the combustion gas flow direction of the flue 13 changes from the vertical direction to the horizontal direction, and is therefore easily affected by the drift. In such a case, deviation of the combustion gas flow rate in the vertical direction (Z direction) can be suppressed by providing the deviation plate 81 only in the lower portion without providing the deviation plate 81 in the upper portion. Therefore, the amount of heat absorbed by the fluid flowing in the heat transfer tube 43 is adjusted, and the local temperature rise of the heat transfer tube due to the uneven flow rate of the combustion gas is further suppressed, so that damage to the heat transfer tube and deterioration of the heat transfer performance are prevented. Can be suppressed.

Further, in the present embodiment, the drift plate 81 is detachably fixed to the heat transfer tube 43 by the U bolt 83 that is inserted through the oval bolt hole 82. As a result, even when the deflector plate 81 thermally expands in the longitudinal direction (width direction) of the oval shape, it is possible to suppress the interference between the U bolt 83 and the edge of the bolt hole 82. Therefore, damage to the U bolt 83 and the bolt hole 82 and deformation and damage of the heat transfer tube 43 to which the U bolt 83 and the bolt hole 82 are attached can be suppressed. The longitudinal direction of the oval shape is preferably the intersecting direction (Y direction).

Further, in the present embodiment, the widthwise end of the fixed portion 81a of the deflector plate 81 is bent to form the outer portion 81d and the inner portion 81e. In the present embodiment, the outer portion 81d is bent to the downstream side in the combustion gas flow direction (X) direction, and the inner portion 81e is bent to the combustion gas upstream side. As a result, even if the widthwise end of the fixed portion 81a of the non-uniform flow plate 81 comes into contact with the heat transfer tube 43 due to the vibration of the non-uniform flow plate 81 or the like, the end of the non-uniform flow plate 81 and the heat transfer tube 43 are separated from each other. Since they come into surface contact, damage to the heat transfer tube 43 can be suppressed. In addition, in the present embodiment, an example in which the widthwise end of the fixed portion 81a is bent to form the outer portion 81d and the inner portion 81e has been described, but the present invention is not limited to this. For example, the outer portion 81d and the inner portion 81e may be formed by curving the widthwise end of the fixed portion 81a. By forming in this way, the widthwise end of the fixed portion 81a becomes a curved surface, and therefore, when the widthwise end of the fixed portion 81a of the flow deflector 81 and the heat transfer tube 43 contact each other more suitably. Therefore, damage to the heat transfer tube 43 can be suppressed.

Further, in the present embodiment, the inner portion 81e is located between the adjacent heat transfer tubes 43 in a state where the heat transfer tube 43 and the fixed portion 81a are fixed. That is, the inner portion 81e is provided so as to collide with the deflector plate 81 and face the flow of the combustion gas flowing in the width direction along the plate surface of the deflector plate 81. As a result, the inner portion 81e becomes a resistance to the flow of the combustion gas, so that the flow rate of the combustion gas can be reduced in the region where the flow diverter plate 81 is provided.

It is also conceivable to cover the heat transfer tube 43 with a refractory material in order to suppress the local temperature rise of the heat transfer tube 43. However, since the refractory material cannot follow the thermal expansion of the heat transfer tube 43, it may be damaged or fall off. It is also possible to cover the heat transfer tube 43 with a heat insulating material. However, the structure provided with the heat insulating material has low durability in an environment exposed to high temperature combustion gas. Further, when the combustion gas contains a corrosive component, the metal fitting (wire or the like) holding the heat insulating material may be damaged and fall off. The metal fittings and the like that have fallen off are scattered to the downstream side of the flue 13 and adhere to the heat exchangers (reheaters 44, 45, etc.) on the downstream side and the air heater 49 to become a resistance to the combustion gas flow and become a pressure. May increase loss.
On the other hand, in the present embodiment, the drift plate 81 is firmly fixed by the U bolt 83. As a result, the drift plate 81 itself and the material of the fixing portion 81a such as the U bolt 83 can be prevented from falling off.

The present invention is not limited to the invention according to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the invention.
For example, in the above-described embodiment, an oil-fired boiler that uses a liquid fuel such as heavy oil or crude oil has been described as an example of the boiler 10, but the present invention is not limited to this. For example, the fuel is not limited to the liquid fuel, but may be a gas-fired boiler using a gas fuel such as natural gas or by-product gas, and further, a solid fuel such as coal, biomass, petroleum coke, or petroleum residue is used. It may be a solid fuel fired boiler. Further, it can be applied to mixed combustion of these fuels.

In addition, in the above-described embodiment, as shown in FIG. 4, an example in which the plurality of deflector plates 81 are provided so as to obstruct the flow of the combustion gas in the regions at both ends in the width direction of the cross section of the flue 13 has been described. However, the present invention is not limited to this. For example, it may be provided as shown in FIG. As shown in FIG. 8, it may be provided so as to obstruct the central region in the width direction of the cross section of the flue 13. Further, the flue 13 may be provided so as to obstruct the central region in the vertical direction of the cross section.

Further, in the above embodiment, an example in which the deflector plate 81 is provided in the superheater 42 has been described, but the present invention is not limited to this. For example, the superheater 41 may be provided with a deflector plate, and the reheaters 44, 45 and the economizers 46, 47 may be provided with deflector plates.

1: Boiler system 10: Oil-fired boiler (boiler)
11: Furnace 12: Combustion device 13: Flue (combustion gas flow path)
13a: 1st vertical part 13b: Horizontal part 13c: 2nd vertical part 13d: Projection part 13da: 1st inclined surface 13db: 2nd inclined surface 13e: Ceiling wall 41, 42: Superheater (heat exchanger)
43: heat transfer pipe 43a: first vertical pipe part 43b: inclined pipe part 43c: second vertical pipe part 44: second reheater 45: first reheater 46: second coal saver 47: first coal saver Device 48: Gas duct 74: Inlet header 75: Outlet header 81: Drift plate 81a: Fixed part 81b: Upper horizontal part 81c: Lower horizontal part 81d: Outer part (bent part)
81e: Inside part (bent part)
82: Bolt hole 82a: 1st bolt hole 82b: 2nd bolt hole 82c: 3rd bolt hole 82d: 4th bolt hole 82e: 5th bolt hole 82f: 6th bolt hole 83: U bolt 83a: 1st U bolt 83b : Second U bolt 83c: Third U bolt

Claims (8)

A fluid circulates inside, heat-exchanges the high temperature gas having a temperature higher than that of the fluid with the fluid, and a plurality of heat transfer tubes extending in a predetermined direction intersecting the flow direction of the high temperature gas,
A deflector plate detachably fixed to the heat transfer tube,
The plurality of heat transfer tubes are arranged side by side in the flow direction of the high temperature gas, and are arranged side by side in an intersecting direction that intersects both the flow direction of the high temperature gas and the predetermined direction,
The non-uniform flow plate is fixed to the heat transfer pipe arranged at an end portion on the downstream side in the flow direction of the high temperature gas, and the heat exchanger is provided so that the plate surface intersects the flow direction of the high temperature gas. .. A plurality of the drift plates are provided,
The heat exchanger according to claim 1, wherein the plurality of the deflector plates are arranged side by side so that the plate surfaces are along a surface formed in the predetermined direction and the intersecting direction. The heat exchanger according to claim 2, wherein the plurality of the deflector plates are arranged side by side along the predetermined direction. The drift plate has an elliptical bolt hole,
The heat exchanger according to any one of claims 1 to 3, wherein the non-uniform flow plate and the heat transfer tube are fixed by U bolts that pass through the bolt holes. 5. The uneven flow plate has a bent portion extending from an end portion of the plate surface in the intersecting direction by bending to an upstream side or a downstream side direction in a flow direction of the high temperature gas. The heat exchanger according to claim 1. A heat exchanger according to any one of claims 1 to 5,
A combustion gas flow path through which the combustion gas generated in the furnace flows,
The heat exchanger is provided in the combustion gas passage,
A boiler in which the high-temperature gas is the combustion gas. The boiler according to claim 6, wherein the heat exchanger is a superheater. A method of adjusting heat absorption of a heat exchanger,
The heat exchanger is
A fluid circulates inside, heat-exchanges the high temperature gas having a temperature higher than that of the fluid with the fluid, and a plurality of heat transfer tubes extending in a predetermined direction intersecting the flow direction of the high temperature gas,
A deflector plate detachably fixed to the heat transfer tube,
The plurality of heat transfer tubes are arranged side by side in the flow direction of the high temperature gas, and are arranged side by side in an intersecting direction that intersects both the flow direction of the high temperature gas and the predetermined direction,
The non-uniform flow plate is fixed to the heat transfer pipe arranged at a downstream end in the flow direction of the high temperature gas, and the plate surface is provided so as to intersect with the flow direction of the high temperature gas,
A method for adjusting the amount of heat absorbed by a heat exchanger, comprising the step of changing the flow of the high-temperature gas with the flow deflector.

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