JP7353074B2 - boiler - Google Patents

Description

The present disclosure relates to boilers .

Patent Document 1 describes a solid fuel-fired boiler that uses pulverized coal as solid fuel. The solid fuel-fired burner for injecting pulverized coal and air into the furnace of this boiler consists of a pulverized coal burner for injecting pulverized coal and primary air, and a pulverized coal burner for injecting secondary air from above and below the pulverized coal burner. By injecting the same amount of secondary air from each secondary air inlet port, uniform combustion is achieved.

In a boiler that co-fires gas fuel or liquid fuel such as oil and coal, if gas fuel or liquid fuel is not used, the nozzle for supplying gas fuel or liquid fuel is used for supplying air for coal combustion. Often used as a nozzle. However, when burning coal, the amount of air required to burn gas or liquid fuel is often too large, so the air flow rate is reduced to supply the amount of air necessary for burning coal. In this case, mixing of air and coal is delayed, which causes deterioration of boiler performance.

As a conventional nozzle for supplying gaseous or liquid fuel, a nozzle 100 having the configuration shown in FIGS. 6 and 7, for example, can be used. The nozzle 100 includes three cylindrical port members 101a, 101b, 101c in which flow paths 102a, 102b, 102c for air supply are formed, respectively, and a cylinder in which a flow path 104 for gas fuel or liquid fuel supply is formed. The port member 103 has a shape. Three cylindrical port members 101a, 101b, and 101c are arranged in a line in the vertical direction, and a port member 103 is provided so as to be included in the middle port member 101b.

As shown in FIG. 7, each of the channels 102a, 102b, and 102c communicates with an air supply source (not shown) via channels 105a, 105b, and 105c. Dampers 106a, 106b, 106c are installed in each of the flow paths 105a, 105b, 105c to adjust the flow rate of air, and dampers 106b are closed when only coal is burned, thereby suppressing deterioration in boiler performance. I can do it.

Patent No. 5778500

However, although the nozzle 100 can ensure the flow velocity of air flowing through each of the flow paths 102a and 102c when gas fuel or liquid fuel is not used, a gap is formed between each port member, and some of the air is It will flow out through this gap. Since the flow rate of air flowing out of such a gap is slow, there is a problem that the air immediately diffuses into the surroundings after flowing out of the gap, and is not effectively utilized for combustion.

In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a boiler that can effectively increase the amount of air used for combustion.

A boiler according to at least one embodiment of the present disclosure includes a cylindrical casing in which a plurality of air channels through which air flows are partitioned by a partition wall, and a cylindrical casing provided inside the casing. The inside of the wall member is equipped with a nozzle in which a fuel flow path through which gaseous fuel or liquid fuel flows is defined, and a wind box provided to communicate with the nozzle. It is connected to the end of a fuel pipe provided to extend inside the box , and the fuel pipe is provided with a flexible pipe section .
Further, in the boiler according to at least one embodiment of the present disclosure, a plurality of air channels through which air circulates are partitioned by a partition wall inside the cylindrical casing, and a plurality of air passages are provided inside the casing. The inside of the cylindrical wall member is provided with a nozzle in which a fuel flow path through which gaseous fuel or liquid fuel flows is defined, and a wind box provided to communicate with the nozzle. , is connected to the end of the fuel pipe provided to extend inside the wind box, and the outer peripheral surface of the wall member has a cross-sectional shape curved in a convex arc from the upstream end of the fuel flow path toward the downstream side. It has a curved part.

According to at least one embodiment of the present disclosure, since the plurality of air channels through which air flows are divided, there is no gap between adjacent air channels, so that air can be effectively used for combustion. The amount can be increased.

FIG. 1 is a diagram schematically showing a partial configuration of a boiler according to an embodiment of the present disclosure. FIG. 1 is a front end view schematically showing the configuration of a nozzle according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view schematically showing the configuration of a nozzle and a wind box provided to communicate with the nozzle according to an embodiment of the present disclosure. FIG. 7 is a front end view schematically showing the configuration of a nozzle according to another embodiment of the present disclosure. FIG. 7 is a cross-sectional view schematically showing the configuration of a nozzle and a wind box provided to communicate with the nozzle according to another embodiment of the present disclosure. FIG. 2 is a front end view showing an example of a conventional nozzle. FIG. 2 is a cross-sectional view showing an example of a conventional nozzle.

Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative arrangements, etc. of the components described in the following embodiments are not intended to limit the scope of the present invention, and are merely illustrative examples.

As shown in FIG. 1, a boiler 1 according to an embodiment of the present disclosure uses gas fuel or liquid fuel (gas fuel will be explained below as an example, but liquid fuel such as oil may also be used). This boiler co-fires coal and coal, and includes a furnace 2 and a burner section 3 provided in the furnace 2. The burner section 3 includes a nozzle 4 for supplying air, a nozzle 5 for supplying coal, a nozzle 6 for supplying gas fuel and air, and a wind box 7 provided to communicate with each of the nozzles 4 to 6. It is equipped with Note that the nozzles 5 and 6 each supply coal and gas fuel and burn them, so they have the configuration of a burner.

As shown in FIG. 2, the nozzle 6 includes a cylindrical housing 14 having a rectangular cross-sectional shape, and two partition walls 10a and 10b provided within the housing 14 facing each other and spaced apart from each other. It includes a cylindrical wall member 12 having a rectangular cross-sectional shape. The two partition walls 10a and 10b divide the inside of the housing 14 into three regions, and these three regions constitute three air channels 11a, 11b, and 11c through which air flows. The wall member 12 is provided in an air flow path 11b located in the middle of the three air flow paths, and a fuel flow path 13 through which gas fuel flows is formed inside the wall member 12. The air flow paths 11a, 11b, 11c and the fuel flow path 13 are divided by the partition walls 10a, 10b and the wall member 12 within the housing 14, so that between the air flow paths 11a, 11b, the air flow paths 11b, 11c There is no gap between the air flow path 11b and the fuel flow path 13.

As shown in FIG. 3, in the wind box 7 communicating with the nozzle 6, two partition plates 23a and 23b each having an L-shaped cross section are provided so as to face each other with a gap between them. The inside of the wind box 7 is divided into three regions by the partition plates 23a and 23b, and these three regions communicate with any one of the air channels 11a, 11b, and 11c. A region communicating with the air flow path 11a constitutes an internal flow path 24, a region communicating with the air flow path 11b constitutes an internal flow path 25, and a region communicating with the air flow path 11c constitutes an internal flow path 26. .

An end of the wall member 12 is connected to an end of a fuel pipe 21 provided so as to extend from the outside of the wind box 7 through the wind box 7 and inside the wind box 7 . With this configuration, gas fuel can be supplied from the gas fuel supply source provided outside the wind box 7 to the fuel flow path 13 via the fuel pipe 21. Further, the fuel pipe 21 may be provided with a flexible pipe section 22 .

Each of the internal channels 24 to 26 is provided with dampers 31, 32, and 33, which are air flow rate adjusting members for adjusting the flow rate of air supplied into the wind box 7 through each internal channel in an operation described later. It may be provided. Each of the dampers 31 to 33 may be electrically connected to a control unit 30 that controls each of the dampers 31 to 33 so as to adjust the flow rate of air flowing through each of the internal channels 24 to 26. The control section 30 is electrically connected to a boiler output detection section 40 that detects the output of the boiler 1 (see FIG. 1). The configuration of the boiler output detection section 40 is not particularly limited, but may be, for example, a power generation amount detector for detecting the amount of power generation in a power generation device (not shown) that generates power using steam generated in the boiler 1. For example, a map defining the relationship between the output of the boiler 1 and the opening degree of each of the dampers 31 to 33 can be pre-installed in the control unit 30.

The nozzle 6 may be connected to the wind box 7 so as to be rotatable in the vertical direction (in the direction of arrow A). When the nozzle 6 is rotatable in the vertical direction, the outer circumferential surface 12a of the wall member 12 has a curved portion 15 having a cross-sectional shape that is curved in a convex arc shape toward the downstream side from the upstream end 13a of the fuel flow path 13. It may be configured to have. With this configuration, when one end of the wall member 12 is inserted into the fuel pipe 21 and the two are connected, the curved portion 15 comes into contact with the inner wall 21a of the fuel pipe 21. Then, even if the nozzle 6 is rotated in the vertical direction, the contact of the curved portion 15 with the inner wall 21a of the fuel pipe 21 is maintained, so there is a risk that a gap may occur at the connection between the wall member 12 and the fuel pipe 21. can be reduced.

Further, one end of the partition walls 10a, 10b is inserted between the partition plates 23a, 23b, that is, into the internal flow path 25, so that the partition walls 10a, 10b and the partition plates 23a, 23b are in contact with each other. Thus, the air flow path 11b and the internal flow path 25 can be communicated with each other. In this case, curved portions 10a1 and 10b1 having the same configuration as the curved portion 15 may be provided on each of the partition walls 10a and 10b. When curved portions 10a1 and 10b1 are provided on partition walls 10a and 10b, respectively, curved portions 10a1 and 10b1 abut against partition plates 23a and 23b, respectively. Then, even if the nozzle 6 is rotated in the vertical direction, the curved portions 10a1 and 10b1 are maintained in contact with the partition plates 23a and 23b, respectively, so that the connecting portion between the air flow path 11b and the internal flow path 25 is It is possible to reduce the possibility that a gap will occur.

Furthermore, a part of one end side of the housing 14 is inserted into the wind box 7 so that the outer peripheral surface 14a of the housing 14 and the inner peripheral surface 7a of the wind box 7 are in contact with each other, The air channels 11a and 11c can communicate with the internal channels 24 and 26, but in this case, a curved portion 14a1 having the same configuration as the curved portion 15 is provided on the outer peripheral surface 14a of the housing 14. Good too. When the curved portion 14a1 is provided on the outer peripheral surface 14a of the housing 14, the curved portion 14a1 comes into contact with the inner peripheral surface 7a of the wind box 7. Then, even if the nozzle 6 is rotated in the vertical direction, the curved portion 14a1 is maintained in contact with the inner circumferential surface 7a of the wind box 7, so that the air flow paths 11a, 11c and the internal flow paths 24, 26 are It is possible to reduce the possibility that a gap will occur in the connecting portion of the.

Next, the operation of the boiler 1 according to this embodiment will be explained. As shown in FIG. 1, coal and gas fuel are supplied to each of the nozzles 5 and 6 via a supply line (not shown). Furthermore, air is supplied to each wind box 7 via an air supply line (not shown). Air is supplied into the furnace 2 through the nozzle 4, coal and air are supplied into the furnace 2 through the nozzle 5, and gas fuel and air are supplied into the furnace 2 through the nozzle 6. The coal supplied from the nozzle 5 and the gas fuel supplied from the nozzle 6 are combusted in the furnace 2, and the heat obtained from the combustion is transferred to water in a heat exchanger (not shown) to generate water vapor. It is possible to generate electricity using a power generation device (not shown).

As shown in FIG. 3, the air supplied to the wind box 7 communicating with the nozzle 6 flows through each air flow path 11a to 11c of the nozzle 6 and is supplied into the furnace 2. On the other hand, gas fuel supplied from a supply source (not shown) flows through the fuel pipe 21, then through the fuel flow path 13, is supplied into the furnace 2, and is combusted by the air supplied into the furnace 2. As described above, in the nozzle 6, there is no gap between the air channels 11a and 11b, between the air channels 11b and 11c, and between the air channel 11b and the fuel channel 13. If such a gap exists, the air ejected from the gap will immediately diffuse into the surrounding area and will not be effectively used for combustion. In other words, the amount of air used for combustion can be effectively increased. As a result, it is possible to suppress performance deterioration of the boiler 1 due to a reduction in air that is not effectively utilized for combustion.

Further, an internal flow path 24 communicating with the air flow path 11a, an internal flow path 25 communicating with the air flow path 11b, and an internal flow path 26 communicating with the air flow path 11c are formed in the wind box 7, When dampers 31 to 33 are provided in each of the internal channels 24 to 26, the air flow rate from each of the air channels 11a to 11c can be adjusted depending on the operating status of the boiler 1.

For example, when only coal combustion is performed without burning gas fuel, the dampers 31 and 33 are fully opened and the damper 32 is set to about 5%, that is, the damper 32 is slightly opened. By doing so, air may be supplied into the furnace 2 through the air channels 11a and 11c located at the uppermost and lowermost sides of the nozzle 6. Alternatively, by fully opening the damper 32 and setting the opening degrees of the dampers 31 and 33 to about 5%, that is, by slightly opening the dampers 31 and 33, the nozzle 6 can be located at the center. Air may be supplied into the furnace 2 through the air passage 11b. Furthermore, although the opening degree when the dampers 31 to 33 are slightly opened is "approximately 5%," this is merely an example of the approximate opening degree, and the specific opening degree can be adjusted depending on the situation. It is.

Furthermore, when a control section 30 that controls the opening degree of each damper 31 to 33 and a boiler output detection section 40 that is a power generation amount detector or the like for detecting the amount of power generation in a power generation device (not shown) are provided, the control section 30 controls the opening degree of each damper 31 to 33 based on a map pre-installed in the control unit 30 from the detected value by the boiler output detection unit 40, so that according to the output of the boiler 1, The air flow rate from each of the air channels 11a to 11c can be adjusted.

For example, when both gas fuel combustion and coal combustion are performed, the opening degree of each damper 31 to 33 is set to 60 to 100 based on the detected value by the boiler output detection unit 40 and a map installed in the control unit 30 in advance. It can be controlled within a range of %.

In this embodiment, the number of air flow paths is three, but the number is not limited to three, and the number is not limited as long as it is at least two. Further, although FIG. 1 shows two nozzles 4 and 5 each and one nozzle 6, the number of each nozzle can be determined arbitrarily depending on the size of the boiler 1, etc. It can be changed to

Note that the characteristic configuration of the nozzle 6 can be applied not only to a burner but also to an air nozzle. For example, FIG. 4 shows an air supply nozzle 50 installed in a coal-fired boiler, but this nozzle 50 has the characteristic configuration of the nozzle 6 (FIGS. 2 and 3). be.

The nozzle 50 includes a cylindrical housing 54 having a rectangular cross-sectional shape, and two partition walls 50a and 50b that face each other and are spaced apart within the housing 54. The two partition walls 50a and 50b divide the inside of the housing 54 into three regions, and these three regions constitute three air channels 51a, 51b, and 51c through which air flows. Since the air channels 51a, 51b, 51c are divided by the partition walls 50a, 50b within the housing 54, there is no gap between the air channels 51a, 51b or between the air channels 51b, 51c. .

As shown in FIG. 5, an air supply nozzle 50 provided in the coal-fired boiler is provided with a wind box 7 that communicates with the nozzle 50, similar to the boiler 1 according to the embodiment described above. By providing two partition plates 23a and 23b in the wind box 7 so as to face each other with an interval, the inside of the wind box 7 is partitioned into three regions, and the region communicating with the air flow path 51a is closed to the internal flow. The channel 24 may be defined as the internal channel 24, the region communicating with the air channel 51b may be defined as the internal channel 25, and the region communicating with the air channel 51c may be defined as the internal channel 26.

Each of the partition walls 50a and 50b had the same configuration as the curved portions 10a1 and 10b1 (see FIG. 3) provided on each of the partition walls 10a and 10b (see FIG. 3) of the nozzle 6 (see FIG. 3). Curved portions 50a1 and 50b1 may be provided. Further, a curved portion 54a1 having the same configuration as the curved portion 14a1 provided on the outer peripheral surface 14a (see FIG. 3) of the housing 14 (see FIG. 3) may be provided on the outer peripheral surface 54a of the housing 54. . Thereby, even if the nozzle 50 is rotated when the nozzle 50 is provided so as to be rotatable in the direction of the arrow A, the connecting portion between the air flow path 51b and the internal flow path 25, the air flow paths 51a and 51c It is possible to reduce the possibility that a gap will occur in any of the connecting portions between the connecting portions and the internal flow paths 24 and 26.

Furthermore, similarly to the boiler 1 according to the embodiment described above, dampers 31, 32, and 33 may be provided in each of the internal flow paths 24 to 26, and each of the dampers 31 to 33 is electrically connected to the control unit 30. You may. The control unit 30 is electrically connected to a boiler output detection unit 40 that detects the output of the coal-fired boiler in which the nozzle 50 is provided.

In the nozzle 50, as in the nozzle 6 (see FIG. 3), there is no gap between the air channels 51a and 51b and between the air channels 51b and 51c, so the amount of air that can be effectively used for combustion is reduced. can be increased. As a result, it is possible to suppress deterioration in boiler performance due to a reduction in air that is not effectively utilized for combustion.

Furthermore, similarly to the boiler 1, when the dampers 31 to 33 are provided, the air flow rate from each of the air passages 51a to 51c can be adjusted depending on the operating conditions of the boiler. Furthermore, when a control unit 30 that controls the opening degree of each damper 31 to 33 and a boiler output detection unit 40 are provided, the air flow rate from each of the air flow paths 51a to 51c is adjusted according to the output of the boiler. What can be done is also similar to boiler 1.

For example, when the boiler output detection unit 40 detects that the power generation load is 100%, the control unit 30 controls the dampers 31 to 33 so that the dampers 31 to 33 are fully open (the opening degree is 100%). control. This allows the maximum flow rate of air to be supplied. Further, when the boiler output detection unit 40 detects that the power generation load is 50%, the control unit 30 sets the opening degree of the damper 32 to about 5% while leaving the opening degrees of the dampers 31 and 33 unchanged. The dampers 31 to 33 are controlled so that the damper 32 is slightly opened. Thereby, air can be supplied at a flow rate that provides a combustion state suitable for a power generation load of 50%. Furthermore, when the boiler output detection section 40 detects that the power generation load is 30%, the control section 30 controls the damper 32 to be fully closed (the opening degree is 0%) and the opening degree of the dampers 31 and 33 to be The dampers 31 to 33 are controlled so that the distance is approximately 5%, that is, the dampers 31 and 33 are in a slightly open state. Thereby, air can be supplied at a flow rate that provides a combustion state suitable for a power generation load of 30%.

1 Boiler 6 Nozzle 7 Wind box 10a Partition wall 10b Partition wall 11a Air flow path 11b Air flow path 11c Air flow path 12 Wall member 12a Outer peripheral surface 13 (of the wall member) Fuel flow path 13a Upstream end 14 (of the fuel flow path) Housing 15 Curved portion 24 Internal flow path 25 Internal flow path 26 Internal flow path 30 Control unit 31 Damper 32 Damper 33 Damper 40 Boiler output detection unit 50 Nozzle 50a Partition wall 50b Partition wall 51a Air flow path 51b Air flow path 51c Air flow Route 54 Housing

Claims (4)

Inside the cylindrical casing, a plurality of air channels through which air flows are divided by partition walls, and inside the cylindrical wall member provided inside the casing, gas fuel or liquid is stored. a nozzle in which a fuel flow path through which fuel flows is divided;
a wind box provided to communicate with the nozzle,
An end of the wall member is connected to an end of a fuel pipe provided to extend within the wind box ,
A boiler in which the fuel pipe is provided with a flexible pipe section . Inside the cylindrical casing, a plurality of air channels through which air flows are divided by partition walls, and inside the cylindrical wall member provided inside the casing, gas fuel or liquid is stored. a nozzle in which a fuel flow path through which fuel flows is divided;
a wind box provided to communicate with the nozzle;
Equipped with
An end of the wall member is connected to an end of a fuel pipe provided to extend within the wind box,
In the boiler , the outer peripheral surface of the wall member has a curved section having a cross-sectional shape that is curved in a convex arc shape from the upstream end of the fuel flow path toward the downstream side. An internal flow path communicating with each of the plurality of air flow paths is formed inside the wind box,
The boiler according to claim 1 or 2 , wherein each internal flow path is provided with an air flow rate adjustment member that adjusts the flow rate of air flowing through each internal flow path. a boiler output detection unit that detects the output of the boiler;
and a control unit that controls the air flow rate adjustment member,
The boiler according to claim 3 , wherein the control section adjusts the flow rate of air flowing through each internal flow path based on the detected value by the boiler output detection section.

Images