JP2021067449A - Boiler and power generation plant including the same - Google Patents

Abstract

To provide a boiler enabling reduction of use amount of a high functional material and construction cost of an entire plant and a power generation plant including the boiler.SOLUTION: A boiler includes: a furnace 1; a burner 2 provided on an inner side wall of the furnace 1 to burn fuel and generate combustion gas; a combustion gas discharge port 1a provided on a lower side wall of the furnace 1 and serving as an outlet of combustion gas from the furnace 1; a combustion gas flow passage 3 that is connected to the combustion gas discharge port 1a and from which combustion gas passes; and a heat transfer part 4 provided in the combustion gas flow passage 3 and having a plurality of heat transfer pipes 18 exchanging heat with the combustion gas to generate steam or increase a temperature thereof. The combustion gas flow passage 3 is installed at a ground level 17.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a boiler and a power plant equipped with the boiler.

The power generation efficiency of a thermal power plant is greatly affected by steam conditions. Therefore, in recent years, in order to further improve the power generation efficiency, it is required to raise the temperature of the superheated steam supplied to the steam turbine to, for example, 600 ° C. or higher.
On the other hand, such high temperature of steam conditions has a great influence on the selection of steam piping material, and as the temperature of superheated steam rises, high-performance materials with high pressure resistance, high temperature resistance, and high temperature corrosion resistance that can withstand it are used. The amount of piping used will increase. As a result, the cost of steam piping using high-performance materials will occupy a large proportion of the total construction cost of thermal power plants.

Therefore, as a technique for reducing the cost of steam piping using high-performance materials, Patent Document 1 includes a thermal power plant including a boiler building composed of an above-ground building and an underground building formed by digging underground. The power plant is disclosed.

In the case of a conventional thermal power plant, for example, the height of the vertical boiler exceeds 70 m, which is more than twice the height of the turbine building. Therefore, the steam pipe connection port at the upper end of the vertical boiler and the main turbine side A large height difference occurs between the steam stop valve and the combined reheat valve. However, according to this thermal power plant, the height position of the steam pipe connection port at the upper end of the vertical boiler will be the same as the installation height position of the main steam stop valve and combined reheat valve in the adjacent turbine building. In addition, since the vertical boiler is installed inside the boiler building, it is possible to shorten the length of the main steam pipe and reheat steam pipe.

Japanese Unexamined Patent Publication No. 2010-43562

However, in order to actually form a boiler building in the ground, it is necessary to dig deep into the ground, so even if the amount of high-performance materials used can be reduced, enormous construction costs will be incurred, and thermal power generation. It is difficult to adopt it as a technology to reduce the construction cost of the entire power plant.

This disclosure has been made in view of such circumstances, and provides a boiler capable of reducing the amount of high-performance materials used and the construction cost of the plant as a whole, and a power plant equipped with the boiler. The purpose.

The boiler according to at least one embodiment of the present disclosure is provided on the furnace, a burner provided on the inner side wall of the furnace to burn fuel to generate combustion gas, and a burner provided below the burner on the inner side wall of the furnace. A combustion gas discharge port which is an outlet of the combustion gas from the furnace, a combustion gas flow path connected to the combustion gas discharge port through which the combustion gas passes, and the combustion provided in the combustion gas flow path. A heat transfer unit having a plurality of heat transfer tubes that exchange heat with gas to generate or raise the temperature of steam is provided, and the combustion gas flow path is installed at the ground level.

According to the boiler of the present disclosure and a power plant equipped with the boiler, a boiler capable of reducing the amount of expensive high-performance materials used and the construction cost of the entire plant, and a power plant equipped with the boiler are provided. Can be done.

It is a schematic diagram which shows an example of the boiler and the power plant which concerns on one Embodiment of this disclosure, and is the figure which shows the example of the boiler and the power plant which use liquid fuel or gas fuel as fuel. It is the schematic which shows an example of the boiler which concerns on one Embodiment of this disclosure, and the steel frame structure which supports the heat transfer part of a boiler. It is the schematic which shows an example of the boiler which concerns on one Embodiment of this disclosure, and the steel frame structure which supports the heat transfer part of a boiler. It is the schematic which shows an example of the boiler which concerns on one Embodiment of this disclosure, and the steel frame structure which supports the heat transfer part of a boiler. It is a schematic diagram which shows an example of the boiler and the power generation plant which concerns on one Embodiment of this disclosure, and is the figure which shows the example of the boiler and the power generation plant which use solid fuel as a fuel. It is the schematic which shows the header structure in the conventional boiler. It is the schematic which shows an example of the heat transfer part (one side steam extraction type) of the boiler which concerns on one Embodiment of this disclosure. It is the schematic which shows an example of the heat transfer part (plurality headers) of the boiler which concerns on one Embodiment of this disclosure. It is the schematic which shows an example of the heat transfer part (plural header alternating connection type) of the boiler which concerns on one Embodiment of this disclosure. It is a schematic diagram which shows an example of a boiler and a power plant which concerns on one Embodiment of this disclosure, and is the schematic diagram which shows an example of the arrangement of a steam turbine (steam load). It is a schematic diagram which shows an example of a boiler and a power plant which concerns on one Embodiment of this disclosure, and is the schematic diagram which shows an example of the arrangement of a steam turbine (steam load).

Hereinafter, the boiler and the power plant according to the embodiment of the present disclosure will be described with reference to FIGS. 1 to 9.

FIG. 1 is a schematic view showing an example of a boiler and a power plant according to an embodiment of the present disclosure.

The power generation plant A of the present embodiment is a thermal power generation plant, and as shown in FIG. 1, a boiler for burning a liquid fuel such as oil or a gaseous fuel such as LNG (liquefied natural gas) to generate steam. It is configured to include B and a steam turbine (steam load) C to which steam generated by the boiler B is supplied and driven.

In the boiler B of the present embodiment, the burner main body 2 is provided on the side wall or the corner portion of the upper part of the boiler furnace (fire furnace) 1, and the combustion gas discharge port 1a is provided at the lower portion thereof, and further, the combustion gas discharge port 1a A combustion gas flow path 3 is provided in communication with the above. That is, the boiler B of the present embodiment is provided with a combustion gas discharge port 1a and a combustion gas flow path 3 below the burner (burner main body 2) on the inner side wall of the boiler furnace 1.

On the other hand, the combustion air sent by the forced ventilator 8 is heated to a predetermined temperature in the air preheater 7, and is sent to the burner main body 2 through the combustion air duct 9. Further, the fuel is sent to the burner main body 2 from a fuel supply facility (not shown), and is injected from the burner nozzle 2a into the boiler furnace 1. The injected fuel is ignited by an ignition source (not shown), diffuses and mixes with the combustion air, and descends while swirling and burning inside the boiler furnace 1.

The combustion gas is discharged to the combustion gas flow path 3 from the combustion gas discharge port 1a which is the outlet of the boiler furnace 1 provided on the lower side wall of the boiler furnace 1, and is discharged to the combustion gas flow path 3 and is discharged to the heat transfer unit 4 (superheater 4a, reheater 4b). , The economizer 5, the denitration device 6, the air preheater 7, and the electrostatic collector 10, and then the air is discharged from the chimney 12 to the atmosphere by the attracting ventilator 11.
The combustion gas that has passed through the combustion gas flow path 3 may be introduced into the furnace again via the gas recirculation fan 14 provided on the gas recirculation duct 13.

2 (a), 2 (b), and 2 (c) are schematic views showing an example of the boiler B of the present embodiment and the steel frame structure 16 that supports the heat transfer portion 4 of the boiler B.

The heat transfer unit 4 is provided inside a combustion gas flow path 3 connected to a combustion gas discharge port 1a provided by opening in the lower side wall of the boiler furnace 1.

Here, since the heat transfer unit 4 is composed of a large number of heat transfer tubes 18 arranged in a dense state, it is a particularly heavy device among the devices constituting the boiler B.
Normally (conventional), since the combustion gas flow path 3 and the heat transfer portion 4 are located at a high position of the boiler B, the steel structure 16 assembled on the outside of the boiler B whose position is held by the suspending member 15 The height will also be very high.

On the other hand, in the boiler B of the present embodiment, as shown in FIGS. 2 (a), 2 (b), and 2 (c), the combustion gas flow path 3 is installed at the ground level 17. Further, in the boiler B of the present embodiment, the lower surface 3b of the combustion gas flow path 3 is configured to have the same installation height as the lower surface 1b of the boiler furnace 1.

Here, the "ground level 17" in the present disclosure does not strictly indicate the ground (ground surface) level at the position where the boiler B is installed (including the surrounding position) or the upper surface of the floor slab, and refers to the boiler B. It means a low place near the installation surface 30 of the part to be installed.

For example, in the boiler B of the present embodiment using liquid fuel or gaseous fuel, the combustion gas of the combustion gas flow path 3 passes through as shown in FIG. 2 (c) (FIGS. 2 (a) and 2 (b)). The maximum flow path height is H, and the height difference (absolute value) between the lower surface 3b position of the combustion gas flow path 3 (at least a part of the lower surface 3b position) and the base end 16a position of the steel structure 16 is ΔH1. When this is done, it is configured to satisfy the relationship of ΔH1 ≦ 1H.
The lower surface 3b position (ground level 17) of the combustion gas flow path 3 may be above or below the base end 16a position (installation surface 30) of the steel frame structure 16.

Since the combustion gas flow path 3 is provided at a low height position of the ground level 17 in this way, the steel frame structure 16 for supporting the heat transfer portion 4 also needs to have a low height. Therefore, the amount of steel frame used for the steel frame structure 16 and the installation cost can be significantly reduced.

Further, as shown in FIGS. 2 (b) and 2 (c), if there are devices to be arranged under the boiler furnace 1, a space for storing only those devices may be provided in the ground. The ground level 17 may be set at a height at which the equipment can be installed under the boiler furnace 1. In any case, the combustion gas flow path 3 is installed at a low ground level 17 with respect to the height of the entire boiler.

Further, examples of the equipment to be arranged under the boiler furnace 1 include a recirculation fan 14 and piping.

On the other hand, as shown in FIG. 3, the power generation plant A of the present embodiment is driven by supplying and driving a boiler B for burning solid fuel such as coal or biomass to generate steam and steam generated by the boiler B. Of course, the steam turbine (steam load) C may be provided.

In the boiler B for burning solid fuel such as coal or biomass to generate steam, for example, the lower end side of the boiler furnace 1 is formed in a hopper shape, and the ash generated in the boiler furnace 1 is placed below the boiler furnace 1. It is configured to be discharged by the bottom ash dispensing device 32 installed in.

Therefore, in the boiler B as shown in FIG. 3, as the equipment to be arranged under the boiler furnace 1, a furnace bottom ash dispensing device 32 and the like can be mentioned, and the lower surface 3b of the combustion gas flow path 3 is the boiler furnace 1. The installation height is different from the lower surface 1b of the hopper.

Further, in the boiler B for burning solid fuel such as coal or biomass to generate steam, for example, as shown in FIG. 3, the maximum flow path height through which the combustion gas of the combustion gas flow path 3 passes is set to H. , When the height difference (absolute value) between the lower surface 3b position of the combustion gas flow path 3 and the base end 16a position of the steel structure 16 is ΔH2, the relationship of ΔH2 ≦ 2H is satisfied. ..
The lower surface 3b position (ground level 17) of the combustion gas flow path 3 may be above or below the base end 16a position (installation surface 30) of the steel frame structure 16.

As a result, the combustion gas flow path 3 is provided at a low height position of the ground level 17, and the steel frame structure 16 for supporting the heat transfer portion 4 also needs to have a low height. Therefore, the amount of steel frame used for the steel frame structure 16 and the installation cost can be significantly reduced.

Next, FIG. 4 is a schematic view showing the heat transfer unit 100 in the conventional boiler. Further, FIG. 5 is a schematic view showing an example of the heat transfer unit 4 (one-sided steam extraction type) of the present embodiment.

The heat transfer unit 4 is, for example, a superheater 4a or a reheater 4b arranged in the combustion gas flow path 3 of the boiler B shown in FIG.

As shown in FIG. 4, the conventional heat transfer unit 100 includes one inlet header 19, one outlet header 21, and a plurality of heat transfer tubes 18 connecting them, and the inlet header 19 and the outlet header 21 are each longitudinal. It has an inlet communication pipe 20 and an outlet communication pipe 22 that communicate with the outside at both ends in the direction.

The inlet header 19 and the outlet header 21 are, for example, cylindrical tubular members extending in a predetermined direction corresponding to the left-right direction of the paper surface of FIG. 4, and are made of metal such as low alloy steel, high alloy steel, and stainless steel. Will be done. Further, the cross-sectional areas of the inlet header 19 and the outlet header 21 in the fluid flow direction are set according to the flow rate of the passing steam.
Incidentally, the "predetermined direction" in FIG. 4 may be either the left-right direction of the paper surface or the front-back direction of the front and back surfaces of the paper surface.

The heat transfer tube 18 is a tubular member that bends and extends in the front and back directions of the paper surface of FIG. 4, and is made of a metal such as low alloy steel, high alloy steel, or stainless steel. A flow path through which a fluid flows is formed in the heat transfer tube 18. The fluid that circulates is, for example, water or steam, and is referred to as steam here. The plurality of heat transfer tubes 18 are arranged along a predetermined direction at a predetermined distance from each other. In FIG. 4, six heat transfer tubes 18 are arranged, but in reality, about 100 to 1000 heat transfer tubes 18 may be arranged.

The steam (fluid) flows into the inlet header 19 via the inlet connecting pipe 20 and flows into each heat transfer pipe 18. The steam flowing inside each heat transfer tube 18 is heated by heat exchange with the combustion gas flowing around the heat transfer tube 18, and the temperature rises. The heated steam flows from the heat transfer tube 18 into the outlet header 21 and is aggregated. The aggregated steam is taken out from each outlet connecting pipe 22 provided in the outlet header 21.

On the other hand, the outlet header 21 in the heat transfer section 4 of FIG. 5, which is one embodiment of the present disclosure, has an outlet communication pipe 22 communicating with the outside only at one end in the longitudinal direction. With this configuration, the number of pipes connected to the outlet header 21 is one, as compared with the configuration shown in FIG. If the pipe is a main steam pipe with strict steam conditions, high-performance materials are used. Therefore, the farther the outlet header 21 and the steam turbine C are from the plant, the more the number of pipes, that is, the effect of cost reduction by shortening the pipe length. Will be large.

Further, as compared with the case where the pipes are connected to both ends of the outlet header 21 as shown in FIG. 4, the pipes can be easily routed in the plant, and the workability at the time of assembling is also improved. The inlet connecting pipe 20 of the inlet header 19 is preferably provided on the same side as the outlet connecting pipe 22 in a predetermined direction.

FIG. 6 is a schematic view showing the configuration of another heat transfer unit 4 (plural header type) according to the embodiment of the present disclosure.

Similar to the heat transfer unit 4 shown in FIG. 5, it is the same in that it has a plurality of heat transfer tubes 18 that communicate the inlet header 19 and the outlet header 21, but the outlet header 21 in the heat transfer unit 4 shown in FIG. 6 is oriented in a predetermined direction. , A first exit header 21a and a second exit header 21b are provided.

Further, the first outlet header 21a is different in that the first outlet connecting pipe 22a is provided at one end in the longitudinal direction, and the second outlet header 21b is provided with the second outlet connecting pipe 22b at one end in the longitudinal direction. Further, the first outlet connecting pipe 22a and the second exit connecting pipe 22b are provided on the same side in a predetermined direction. The plurality of heat transfer tubes 18 include a first heat transfer tube group 18A and a second heat transfer tube group 18B. The other end of each of the plurality of heat transfer tubes 18 of the first heat transfer tube group 18A is connected to the first outlet header 21a, and the plurality of heat transfer tubes 18 of the second heat transfer tube group 18B are connected to the second outlet header 21b. The other end of each is connected.

In a large-scale plant that handles a large amount of steam, the outlet header 21 is also required to have a large diameter and can handle high temperature and high pressure depending on the steam conditions, but it may be difficult to manufacture depending on the manufacturing capacity of the manufacturing plant. .. Even in such a case, by dividing and providing a plurality of outlet headers 21 as in the present embodiment, the number of heat transfer tubes 18 connected to each outlet header 21 can be reduced, so that the amount of steam handled per one can be reduced. It can be reduced and the expansion of the diameter can be suppressed.

Further, since the first outlet connecting pipe 22a and the second outlet connecting pipe 22b are provided on the same side in a predetermined direction, the length of the pipe connected to the steam turbine (steam load) C can be shortened. Furthermore, workability during assembly is also improved. In this embodiment, the first outlet connecting pipe 22a and the second outlet connecting pipe 22b are provided on the same side in a predetermined direction, but they may face in opposite directions.

FIG. 7 is a schematic view showing the configuration of another heat transfer unit 4 (multiple header alternating connection type) according to the embodiment of the present disclosure.

As shown in FIG. 7, in the heat transfer section 4, one end of the plurality of heat transfer tubes 18 of the first heat transfer tube group 18A and one end of the plurality of heat transfer tubes 18 of the second heat transfer tube group 18B are predetermined. It is connected to an entrance header 19 extending in the direction. On the other hand, the other ends of the plurality of heat transfer tubes 18 of the first heat transfer tube group 18A and the second heat transfer tube group 18B alternately with respect to the first outlet header 21a and the second outlet header 21b along a predetermined direction. It is connected. Specifically, in order from the heat transfer tube 18 on the left side in FIG. 7, the first outlet header 21a, the second outlet header 21b, the first outlet header 21a, the second outlet header 21b, and the like are alternately connected. ..

For example, the exit header 21 has three exit headers (the first exit header (21a) and the second exit header (21b, ...) Different from the first exit header (21a)), that is, the first exit. When the header 21a, the second exit header 21b, and the third exit header (not shown) are configured, the first exit header 21a, the second exit header 21b, the third exit header, and the like are connected alternately in this order. Further, for example, the first outlet header 21a, the third exit header, the second exit header 21b, and the like may be alternately connected.

Then, with such a configuration, for example, when the flow velocity and temperature of the flowing combustion gas are unevenly uneven in a predetermined direction (for example, when it is divided into two regions, a high temperature side region and a low temperature side region). Even if they are connected alternately, steam can be aggregated so that the total amount of heat flowing from the heat transfer tubes 18 arranged in each temperature side region into each outlet header 21 is substantially equal.

Next, FIG. 8 is a diagram showing a layout diagram of a steam turbine C, which is a steam load according to the embodiment of the present disclosure, and a diagram showing a power plant A.

In the present embodiment, the steam turbine C has a rotating shaft 24 extending in a direction orthogonal to the longitudinal direction of the outlet header 21 and is installed on the outlet connecting pipe 22 side of the boiler.

In other words, in the present embodiment, the rotating shaft 24 of the steam turbine C is provided so as to extend in a direction intersecting the longitudinal direction of the outlet header 21. Further, with respect to the virtual line S that is orthogonal to the longitudinal direction of the exit header 21 and passes through one end of the exit header 21, the side of the exit header 21 in the longitudinal direction where the other end exists. When the one side region R1 and the side opposite to the one side region R1 are defined as the other side region R2, the steam turbine C is installed in the other side region R2.

Further, in the present embodiment, as shown in FIG. 9, the maximum flow path height through which the combustion gas of the combustion gas flow path 3 passes is H, the position of the lower surface 3b of the combustion gas flow path 3 and the installation position of the steam turbine C. When the difference in height (absolute value) from 31 is ΔH3, it is configured to satisfy the relationship of ΔH3 ≦ 2H.
The lower surface 3b position (ground level 17) of the combustion gas flow path 3 may be above or below the installation position 31 of the steam turbine C. Further, in the present disclosure, when the lower surface 3b position of the combustion gas flow path 3 is above the installation position 31 of the steam turbine C, the installation position 31 of the steam turbine C is the upper end thereof, and the lower surface 3b position of the combustion gas flow path 3 is located. When is lower than the installation position 31 of the steam turbine C, the installation position 31 of the steam turbine C is the lower end thereof.

By arranging in this way, the distance between the outlet connecting pipe 22 provided at one end in the longitudinal direction of the outlet header 21 and the steam turbine C can be suppressed, so that the length of the steam pipe can be shortened.

Further, the steam condition of the power plant A such as the thermal power plant in this embodiment is set to 566 ° C or higher, preferably 600 ° C or higher. In such a case, an expensive high-performance material is used for the main steam pipe or the like. Therefore, the cost reduction effect by shortening the pipe length is very large.
_{In the field of high-efficiency pulverized coal-fired power generation technology (USC), it was confirmed that excellent transmission end efficiency and CO 2} reduction performance can be obtained when the main steam temperature is 566 ° C or higher (reheat steam temperature 593 ° C or higher). ing.

Further, the heat transfer unit 4 is configured to include a heat transfer module (heater 4a, reheater 4b) in which a plurality of heat transfer tubes 18, an inlet header 19 and an outlet header 21 are packaged, as shown in FIG. In addition, the combustion gas flow path 3 may be provided with an additional space 3a for adding a heat transfer module.

By providing the additional space 3a in this way, it is possible to easily add a heat transfer module even if the required specifications are changed in the boiler after construction, so that the modification cost can be reduced. It will be possible.

Although one embodiment of the boiler and power plant of the present disclosure has been described above, the boiler and power plant according to the invention are not limited to the above one embodiment and can be appropriately changed without departing from the spirit thereof. Is.

For example, in the present embodiment, the description has been made assuming that the steam load is the steam turbine C, but the steam load is not necessarily limited to the steam turbine C. For example, it may be a steam load of heat storage equipment, heating equipment, distillation equipment, drying equipment, sterilization equipment, and the like.

Further, the heat transfer unit 4 does not necessarily have to be limited to the configuration of the present embodiment, and a known heat transfer unit configuration may be applied.

Finally, the content described in the embodiment is grasped as follows, for example.

(1) The boiler (boiler B) according to at least one embodiment of the present disclosure is provided on the furnace (boiler furnace 1) and the inner side wall of the furnace, and burns fuel to generate combustion gas (burner main body 2). And the combustion gas discharge port (combustion gas discharge port 1a) provided below the burner on the inner side wall of the furnace, which is the outlet of the combustion gas from the furnace, and the combustion gas connected to the combustion gas discharge port pass through. A heat transfer unit (heat transfer tube 18) provided in the combustion gas flow path (combustion gas flow path 3) and a plurality of heat transfer tubes (heat transfer tubes 18) provided in the combustion gas flow path to exchange heat with the combustion gas to generate or raise the temperature of steam. A heat transfer section 4) is provided, and the combustion gas flow path is installed at the ground level (ground level 17).

According to the boiler of (1) above, combustion is connected to a combustion gas discharge port provided below the burner on the inner side wall of the furnace and has a heat transfer portion having a particularly heavy weight among the equipment constituting the boiler. Steel frames (column members and beam members (top beam, etc.)) used to support the heat transfer part because the gas flow path is installed at a low ground level rather than at a high place where it is generally installed. It is possible to significantly reduce the amount of high-performance materials (high-performance piping, etc.) that are resistant to high pressure, high temperature, and high temperature corrosion, and installation costs.

In addition, by installing it in a low place at the ground level, inspection and maintenance work of the heat transfer surface becomes safe and easy, and it is possible to reduce the scaffolding to be assembled before the work, which reduces the plant operation cost after construction. Is also connected.

The "ground level" in (1) above does not strictly indicate the ground surface (or the upper surface of the floor slab, etc.) at the position where the boiler is installed (including the surrounding position), but the part where the boiler is installed. It means a low place near the installation surface.

(2) The boiler according to another embodiment of the present disclosure is the boiler of the above (1), and the boiler further includes a steel structure (steel structure 16) for supporting the heat transfer portion, and is a fuel. When is a liquid fuel or a gaseous fuel, the maximum flow path height through which the combustion gas of the combustion gas flow path passes is H, the position of the lower surface (lower surface 3b) of the combustion gas flow path and the base end (16a) of the steel structure. When the difference in height from the base end position is ΔH1, the relationship of ΔH1 ≦ 1H is satisfied.

According to the boiler of (2) above, in a boiler using a liquid fuel such as petroleum or a gaseous fuel such as LNG (liquefied natural gas), the ground level is set so as to satisfy the relationship of ΔH1 ≦ 1H. , The above-mentioned action and effect (1) can be preferably obtained.

(3) The boiler according to another embodiment of the present disclosure is the boiler of (2) above, and the lower surface of the combustion gas flow path is configured so that the installation height coincides with the lower surface (lower surface 1b) of the furnace. Has been done.

According to the boiler of (3) above, since the lower surface of the combustion gas flow path has the same installation height as the lower surface of the furnace, the pedestal (bottom support) can be easily constructed.

(4) When the boiler according to another embodiment of the present disclosure is the boiler of the above (1), the boiler further includes a steel structure for supporting a heat transfer portion, and the fuel is a solid fuel. When the maximum flow path height through which the combustion gas of the combustion gas flow path passes is H, and the height difference between the lower surface position of the combustion gas flow path and the base end position of the steel structure is ΔH2, ΔH2 ≦ Satisfy the 2H relationship.

According to the boiler of (4) above, in a boiler using solid fuel such as coal or biomass, a configuration for recovering and removing ash generated in a furnace is required, but the relationship of ΔH2 ≦ 2H is satisfied. By setting the ground level in, it becomes possible to preferably obtain the effect of the above (1).

(5) The boiler according to another embodiment of the present disclosure is the boiler according to any one of (1) to (4) above, and the heat transfer section extends in a predetermined direction, and each of the plurality of heat transfer tubes extends. At least one inlet header (inlet header 19) to which one end of the heat transfer tube is connected, and at least one outlet header (outlet header 21, which extends in a predetermined direction and to which the other end of each of the plurality of heat transfer tubes is connected. 21a, 21b), and has an outlet connecting pipe (exit connecting pipe 22, 22a, 22b) serving as a steam outlet only at one end in the longitudinal direction of the outlet header.

According to the boiler of (5) above, since the heat transfer part normally installed in a high place is installed in a low place, the steam connecting the outlet connecting pipe of the outlet header and the steam load such as a steam turbine. The length of the pipe can be significantly shortened. Further, in general, a configuration having outlet connecting pipes at both ends in the longitudinal direction of the outlet header is adopted, but compared to that configuration, steam is removed from one end by one pipe, so steam. The length of the pipe can be further shortened. In particular, the main steam pipe is a pipe with extremely strict steam conditions, and high-performance materials are used. Therefore, the farther the outlet header and the steam turbine are from the plant, the greater the cost reduction effect of shortening the pipe length can be obtained. .. In addition, by reducing the number of pipes, it becomes easier to handle the pipes in the plant, and the workability at the time of assembly is improved.

(6) The boiler according to another embodiment of the present disclosure is the boiler of the above (5), and at least one exit header includes a first exit header (first exit header 21a) and a first exit header. Includes different second outlet headers (second outlet headers 21b, ...), And the plurality of heat transfer tubes are the first heat transfer tube group (18A) to which the other end is connected to the first outlet header. Includes a second heat transfer tube group (18B), to which the other end is connected to the second outlet header.

According to the boiler of (6) above, the heat transfer section has a plurality of outlet headers of the first outlet header and the second outlet header, and the plurality of heat transfer tubes connect the other end to the first outlet header. The group is divided into a first heat transfer tube group provided in the above direction and a second heat transfer tube group provided by connecting the other end to the second outlet header.

With this configuration, for example, when the manufacturing capacity of the outlet header for large diameter and high temperature / high pressure is insufficient, a plurality of transmissions arranged side by side in the extending direction (predetermined direction) of the inlet header By dividing the heat pipe into two or more groups and connecting them to different outlet headers for each group, the amount of steam handled by one outlet header can be reduced. As a result, it is possible to suppress the expansion of the diameter of the outlet header, and it is possible to obtain the cost reduction effect of shortening the pipe length even in a large-scale plant.

(7) The boiler according to another embodiment of the present disclosure is the boiler of (6) above, and the plurality of heat transfer tubes constituting the first heat transfer tube group and the plurality of heat transfer tubes constituting the second heat transfer tube group. The heat transfer tubes are alternately arranged in a predetermined direction.

According to the boiler of (7) above, even when the flow velocity and temperature of the flowing gas are biased in a predetermined direction in the combustion gas flow path provided with the heat transfer portion, the first By alternately arranging the heat transfer tubes of the heat transfer tube group and the heat transfer tubes of the second heat transfer tube group, the temperature of the steam in each of the headers of the first outlet header and the second outlet header is substantially made uniform. Therefore, it is possible to suppress the temperature non-uniformity caused by the difference in the outlet headers even in the equipment on the downstream side of each outlet header.

(8) The boiler according to another embodiment of the present disclosure is the boiler according to any one of (1) to (7) above, and the heat transfer unit includes a plurality of heat transfer tubes, at least one inlet header, and the like. It is provided with at least one outlet header and at least one heat transfer module (heat transfer module, boiler 4a, reheater 4b) in which is packaged, and a heat transfer module is added to the combustion gas flow path. An expansion space (extension space 3a) is formed.

According to the boiler of (8) above, even if the required specifications are changed in the boiler after construction, it is possible to easily add a heat transfer module, so that the modification cost can be reduced. Become.

(9) The power generation plant according to the embodiment of the present disclosure includes the boiler according to any one of (1) to (8) above and a steam load (steam turbine C) to which steam generated by the boiler is supplied. When the maximum flow path height through which the combustion gas of the combustion gas flow path passes is H, and the height difference between the lower surface position of the combustion gas flow path and the installation position of the steam load (installation position 31) is ΔH3. The relationship of ΔH3 ≦ 2H is satisfied.

According to the power plant of (9) above, the effect of the boiler according to any one of (1) to (8) above can be obtained.
Further, the height difference ΔH3 between the lower surface position of the combustion gas flow path and the installation position of the steam load such as the steam turbine is configured to satisfy the relationship of ΔH3 ≦ 2H, so that the outlet header of the heat transfer part can be used. The length of the steam pipe connecting the outlet connecting pipe and the steam load such as a steam turbine can be significantly shortened.
Further, in particular, the main steam pipe is a pipe whose steam conditions are very strict, and since a high-performance material is used, a large cost reduction effect can be obtained by shortening the pipe length. Furthermore, the number of pipes can be reduced, which makes it easier to handle the pipes in the plant and improves workability during assembly.

(10) The power plant according to the embodiment of the present disclosure includes the boiler according to any one of (5) to (7) above and at least one steam turbine (steam turbine C) rotated by the steam generated by the boiler. , The rotating shaft (rotating shaft 24) of the steam turbine extends in a direction intersecting the longitudinal direction of the outlet header, is orthogonal to the longitudinal direction of the outlet header, and passes through one end of the outlet header. One side region (one side region R1) is the side where the other end in the longitudinal direction of the exit header exists, and the other side region (the other side) is opposite to the one side region. When defined as the side region R2), the steam turbine is installed in the other side region.

According to the power plant of (10) above, since the steam turbine is installed in the other side region, the distance between the outlet connecting pipe provided at one end in the longitudinal direction of the outlet header and the steam turbine is suppressed. Therefore, the length of the steam pipe can be shortened.

(11) The power plant according to the embodiment of the present disclosure is the power plant according to (9) or (10) above, and the steam condition of the power plant is 566 ° C. or higher.

According to the power plant of (11) above, the steam condition is a high temperature condition of 566 ° C or higher, which requires the use of high-performance materials for the main steam pipes, etc., so the cost reduction effect of the entire power plant by shortening the pipe length is effective. It will be bigger.

The boilers and power plants of the present disclosure can be widely applied to coal-fired power plants and the like.

1 Boiler furnace (fire furnace)
1a Combustion gas outlet 1b Bottom surface of the furnace 2 Burner body (burner)
2a Burner nozzle 3 Combustion gas flow path 3a Expansion space 3b Bottom surface of combustion gas flow path 4 Heat transfer part 4a Superheater (heat transfer module)
4b reheater (heat transfer module)
5 Economizer 6 Denitration device 7 Air preheater 8 Push-in ventilator 9 Combustion air duct 10 Electrostatic dust collector 11 Attracting ventilator 12 Chimney 13 Gas recirculation duct 14 Gas recirculation fan 15 Suspended member 16 Steel structure 16a Base end 17 Ground level 18 Heat transfer tube 18A 1st heat transfer tube group 18B 2nd heat transfer tube group 19 Inlet header 20 Inlet connection tube 21 Exit header 21a 1st outlet header 21b 2nd outlet header 22 Outlet connection tube 22a 1st outlet connection tube 22b 1st 2 Outlet connecting pipe 24 Rotating shaft 30 Installation surface 31 Steam load installation position 32 Furnace bottom ash dispenser A Power plant B Boiler C Chimney turbine (steam load)
R1 one side area R2 other side area S virtual line

Claims (11)

With a furnace
A burner provided on the inner side wall of the furnace to burn fuel and generate combustion gas,
A combustion gas discharge port provided below the burner on the inner side wall of the furnace and serving as an outlet for the combustion gas from the furnace.
A combustion gas flow path through which the combustion gas passes, which is connected to the combustion gas discharge port,
A heat transfer unit provided in the combustion gas flow path and having a plurality of heat transfer tubes that exchange heat with the combustion gas to generate or raise the temperature of steam is provided.
The combustion gas flow path is installed at the ground level.
boiler. The boiler further comprises a steel structure for supporting the heat transfer portion.
When the fuel is a liquid fuel or a gaseous fuel,
The maximum flow path height through which the combustion gas passes in the combustion gas flow path is H,
When the difference in height between the lower surface position of the combustion gas flow path and the base end position of the steel frame structure is ΔH1,
Satisfy the relationship of ΔH1 ≦ 1H,
The boiler according to claim 1. The lower surface of the combustion gas flow path is configured so that the installation height coincides with the lower surface of the furnace.
The boiler according to claim 2. The boiler further comprises a steel structure for supporting the heat transfer portion.
When the fuel is a solid fuel,
The maximum flow path height through which the combustion gas passes in the combustion gas flow path is H,
When the difference in height between the lower surface position of the combustion gas flow path and the base end position of the steel frame structure is ΔH2,
Satisfy the relationship of ΔH2 ≦ 2H,
The boiler according to claim 1. The heat transfer section extends in a predetermined direction, and includes at least one inlet header to which one end of each of the plurality of heat transfer tubes is connected, and each of the plurality of heat transfer tubes extending in the predetermined direction. Includes at least one exit header, to which the other end is connected,
Only one end in the longitudinal direction of the outlet header has an outlet connecting pipe that serves as a steam outlet.
The boiler according to any one of claims 1 to 4. The at least one exit header includes a first exit header and a second exit header that is different from the first exit header.
The plurality of heat transfer tubes include a first heat transfer tube group to which other ends are connected to the first outlet header, and a second heat transfer tube group to which other ends are connected to the second outlet header.
The boiler according to claim 5. The plurality of heat transfer tubes constituting the first heat transfer tube group and the plurality of heat transfer tubes constituting the second heat transfer tube group are alternately arranged in the predetermined direction.
The boiler according to claim 6. The heat transfer unit includes at least one heat transfer module in which the plurality of heat transfer tubes, the at least one inlet header, and the at least one outlet header are packaged.
An expansion space for adding the heat transfer module is formed in the combustion gas flow path.
The boiler according to any one of claims 1 to 7. The boiler according to any one of claims 1 to 8 and
With a steam load to which the steam generated by the boiler is supplied,
The maximum flow path height through which the combustion gas passes in the combustion gas flow path is H,
When the difference in height between the lower surface position of the combustion gas flow path and the installation position of the steam load is ΔH3,
Satisfy the relationship of ΔH3 ≦ 2H,
Power plant. The boiler according to any one of claims 5 to 7.
Includes at least one steam turbine that is rotated by the steam produced by the boiler.
The axis of rotation of the steam turbine extends in a direction intersecting the longitudinal direction of the outlet header.
There is an other end of the exit header in the longitudinal direction with respect to a virtual line that is orthogonal to the longitudinal direction of the exit header and passes through the one end of the exit header. When the side is defined as one side region and the side opposite to the one side region is defined as the other side region, the steam turbine is installed in the other side region.
Power plant. The steam condition of the power plant is 566 ° C. or higher.
The power plant according to claim 9 or 10.

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