boiler

Abstract

The present invention provides a boiler capable of increasing rainfall from the upper header. [Solution] According to the present invention, a boiler 1 is provided, comprising a water tube 4, a lower header 3 positioned below the water tube 4 and connected to the lower end 41 of the water tube 4, an upper header 2 positioned above the water tube 4 and connected to the upper end 40 of the water tube 4, and a downpipe 7 connecting the lower header 3 and the upper header 2, wherein the upper header 2 comprises a partition wall 25 and a baffle plate 26, the partition wall 25 is configured to partition the storage space S in which the upper header water within the upper header 2 is stored into a first storage space S1 connected to the water tube 4 and a second storage space S2 connected to the downpipe 7, the baffle plate 26 is positioned above the storage space S and is positioned to cover at least the first storage space S1, and is configured to separate water droplets contained in steam by causing steam flowing from the water tube 4 into the first storage space S1 to collide with the baffle plate 26 and guide the water droplets to the second storage space S2.

Description

Technical Field

[0001] The present invention relates to a separatorless boiler.

Background Art

[0002] Conventionally, for cost reduction and the like, there is a separatorless boiler that does not have a separator for gas-liquid separation to increase the dryness of steam. For example, Patent Document 1 discloses a boiler that includes a downcomer that connects an upper header and a lower header, and lowers the water level in the upper header by allowing the water (upper header water) in the upper header, which has been carried out together with the bubbles in the water pipe, to flow down.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the upper header water is carried out together with the bubbles from the water pipe, there is a risk that when the concentration in the water pipe progresses particularly, the water head pressure becomes insufficient due to the bubbles and the upper header water cannot be sufficiently precipitated.

[0005] The present invention has been made in view of such circumstances, and provides a boiler capable of increasing the precipitation amount from the upper header.

Means for Solving the Problems

[0006] According to the present invention, the following invention is provided. [1] A boiler comprising a water tube, a lower header located below the water tube and connected to the lower end of the water tube, an upper header located above the water tube and connected to the upper end of the water tube, and a downpipe connecting the lower header and the upper header, wherein the upper header comprises a partition wall and a baffle plate, the partition wall is configured to divide the storage space in the upper header where the upper header water is stored into a first storage space connected to the water tube and a second storage space connected to the downpipe, the baffle plate is located above the storage space and is positioned to cover at least the first storage space, and is configured to separate water droplets contained in steam by causing steam flowing from the water tube into the first storage space to collide with the baffle plate and guide the water droplets to the second storage space. A boiler as described in [2][1], wherein a plurality of the water tubes are arranged vertically and in an annular manner, and a burner is located at the center thereof, the upper header is formed in a hollow annular shape along the upper ends of the plurality of water tubes, and has a plurality of first openings in its bottom wall portion that connect to the plurality of water tubes, and a second opening in its outer wall portion that connects to the downpipe, and the partition wall is configured to partition the storage space such that the first storage space is adjacent to the plurality of first openings and the inner wall portion of the upper header, and the second storage space is adjacent to the second opening and the outer wall portion. A boiler as described in [3][2], wherein the baffle plate has an inner surface that abuts against the inner wall and an outer surface that extends beyond the upper part of the partition wall to the vicinity of the outer wall. A boiler according to [4][2] or [3], wherein the partition wall is formed such that the upper part of the first storage space is narrower than the lower part of the first storage space. [Effects of the Invention]

[0007] According to the present invention, since no air bubbles accumulate in the second storage space connected to the rainwater pipe, it is possible to suppress the decrease in water head pressure in the second storage space and increase the amount of rainwater from the rainwater pipe of the upper header water. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing a boiler 1 according to one embodiment of the present invention. [Figure 2] This is a magnified view of the upper header and downpipe of boiler 1 shown in Figure 1. [Figure 3] Figure 3A is a partially enlarged view of Modification 1 of Boiler 1 in Figure 1, and Figure 3B is a partially enlarged view of Modification 2 of the same Boiler 1. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below. The various features shown in the embodiments below can be combined with each other. Furthermore, each feature constitutes an independent invention.

[0010] 1. Configuration of Boiler 1 A boiler 1 according to one embodiment of the present invention is a once-through boiler equipped with a boiler body 5 constructed by connecting an upper header 2 and a lower header 3 with a plurality of water tubes 4, as shown in Figure 1. A burner 6 for heating the water tubes 4 is installed at the top of the boiler body 5. The boiler 1 also includes a downpipe 7 connecting the upper header 2 and the lower header 3, a water level detection means 8 for detecting the water level in the water tubes 4, and a control means 9 on the outside of the boiler body 5. Each of these components will be described in detail below.

[0011] The upper header 2 is composed of an annular hollow container to which the upper ends 40 of multiple water tubes 4 are connected. A steam outlet pipe 20 is connected to the upper header 2, and the steam generated in the water tubes 4 flows out through the upper header 2 and the steam outlet pipe 20 and is supplied to each piece of equipment. In this embodiment, the boiler 1 is a separatorless boiler, meaning that the steam outlet pipe 20 does not have a separator.

[0012] The lower header 3 is composed of an annular hollow container to which the lower ends 41 of multiple water pipes 4 are connected. The lower header 3 is connected to a water supply line 32 to which a check valve 30 and a water supply pump 31 are connected, and to a drain line 34 equipped with a drain valve 33.

[0013] Multiple water tubes 4 are arranged in a ring shape along the vertical direction inside the boiler housing 10, which forms the outer shape of the boiler body 5. Boiler water is held in each water tube 4. In this embodiment, the multiple water tubes 4 constitute an inner water tube group 4A arranged in a ring shape, and an outer water tube group 4B arranged outside the inner water tube group 4A in a ring shape coaxial with the inner water tube group 4A. In the inner water tube group 4A, with some exceptions, adjacent water tubes 4 are arranged in contact with each other. The outer water tube group 4B is spaced apart from the inner water tube group 4A so as to form a predetermined space between them, and is arranged near the inner wall of the boiler housing 10. The central axes of the inner water tube group 4A and the outer water tube group 4B coincide with the central axis of the boiler housing 10.

[0014] The burner 6 is located in the central part of the annular upper header 2. The burner 6 has a fuel injection nozzle and an air supply nozzle (not shown), and injects fuel supplied from the fuel supply line 60, whose amount is adjusted by the fuel supply valve 61, into the boiler housing 10 from the fuel injection nozzle, and supplies air into the boiler housing 10 from the air supply nozzle, releasing a flame downward to burn the fuel and heat the multiple water tubes 4.

[0015] The space below the burner 6 from which the flame is emitted, that is, the space surrounded by the annularly arranged inner water tube group 4A inside the boiler housing 10, constitutes the combustion chamber 62. In the combustion chamber 62, fuel is burned and exhaust gas is generated. The space between the upper outer part of the outer water tube group 4B and the inner wall protruding to the outside of the boiler housing 10 constitutes the exhaust passage 63. The exhaust passage 63 discharges the exhaust gas generated in the combustion chamber 62 from the boiler housing 10 through an exhaust pipe (not shown).

[0016] The rainwater pipe 7 connects the lower header 3 and the upper header 2 on the outside of the boiler body 5, and connects the lower header 3 and the upper header 2. The rainwater pipe 7 allows the boiler water pushed up by the upper header 2 to descend to the lower header 3. The connection portion of the rainwater pipe 7 to the lower header 3 only needs to allow the boiler water inside the rainwater pipe 7 to flow into the lower header 3, and is located in the middle of the lower header 3. On the other hand, the connection portion of the rainwater pipe 7 to the upper header 2 is located at the bottom of the upper header 2 so that the boiler water accumulating inside the upper header 2 can descend as much as possible.

[0017] The water level detection means 8 has a water level control cylinder 80 formed of a conductive material on the outside of the boiler body 5, and upper and lower connecting pipes 81 and 82 connected to the top and bottom of the water level control cylinder 80 connect the water level control cylinder 80 to the upper header 2 and the water level control cylinder 80 to the lower header 3, respectively. In this embodiment, the upper connecting pipe 81 is connected to the upper header 2 at a position above the baffle plate 26, which will be described later.

[0018] Inside the water level control cylinder 80, electrode rods 83 of different lengths are inserted, and by detecting the water level with the tips of the electrode rods 83, the water level inside the water level control cylinder 80 can be detected in stages. For example, if an L-rod 83L and an S-rod 83S which is shorter than the L-rod 83L and detects a higher water level than the L-rod 83L are provided, the water level inside the boiler 5 can be considered to have fallen below a predetermined position when the water level is no longer detected by the S-rod 83S in the case of low combustion, and the water level inside the boiler 5 can be considered to have fallen below a predetermined position when the water level is no longer detected by the L-rod 83L in the case of high combustion.

[0019] When the water level is no longer detected by the electrode rod 83 (for example, after a predetermined time (such as 5 seconds) has elapsed since the detection stopped), the control means 9 described below controls so that water supply to the can body 5 is performed. The water level detected by the electrode rod 83 is determined to be, for example, the dryness limit water level that is ideal when the can water is fresh water (when the electrical conductivity of the can water is the lowest) or a water level lower than that water level. The dryness limit water level is the upper limit water level for maintaining steam with a desired dryness among the water levels of the can water in the can body 5. Note that the number of electrode rods 83 is not limited to two, namely the L rod 83L and the S rod 83S, and it is sufficient that the necessary number according to the combustion stage to be controlled or the like is provided.

[0020] The control means 9 is installed outside the can body 5, and detection signals from a plurality of electrode rods 83 (L rod 83L and S rod 83S) of the water level detection means 8 are input thereto. Further, in response to these detection signals, drive signals are transmitted to drive parts such as the water supply pump 31, the drain valve 33, and the fuel supply valve 61 of the burner 6 to control the drive parts.

[0021] Note that the control means 9 can be configured by, for example, an information processing device including a CPU, a memory (such as a flash memory), an input part, and an output part. Then, the processing by each of the above-described components of the control means 9 configured by the information processing device is performed by the CPU reading and executing a program stored in the memory. As the information processing device, for example, a personal computer, a PLC (programmable logic controller), or a microcomputer is used. However, part of the functions of the control means 9 may be configured to be executed on the cloud connected by an arbitrary communication means.

[0022] 2. Configuration of the upper header 2 The configuration of the upper header 2 of this embodiment will be described in detail below with reference to Figure 2. In Figure 2, the cross-sectional shape of some members is shown so that the internal structure of the upper header 2 can be understood. As described above, the upper header 2 is positioned along a plurality of water pipes 4 arranged in an annular shape, and is formed as a hollow annular shape (hollow donut shape) by a perforated disc-shaped bottom wall portion 21 and top wall portion 22, and a cylindrical inner wall portion 23 and outer wall portion 24. With this configuration, a storage space S is formed in the upper header 2 where boiler water (upper header water) carried out from inside the water pipes 4 along with air bubbles is stored. In addition, a plurality of first openings 21a are formed in the bottom wall portion 21 that connect to the upper ends 40 of each of the plurality of water pipes 4, and a second opening 24a is formed in the outer wall portion 24 that connects to the downspout pipe 7.

[0023] In addition, the upper header 2 of this embodiment is equipped with a partition wall 25 and a baffle plate 26 inside.

[0024] The partition wall 25 is configured to divide the storage space S, where the upper header water is stored, into a first storage space S1 connected to a plurality of water pipes 4 and a second storage space S2 connected to a downspout pipe 7. The partition wall 25 ensures that the first storage space S1 is adjacent to a plurality of first openings 21a and the inner wall portion 23 of the upper header 2, while the second storage space S2 is adjacent to a second opening 24a and the outer wall portion 24.

[0025] Specifically, the partition wall 25 is composed of a base end cylindrical portion 25a supported by the bottom wall portion 21 and tapering upward, a horizontal connecting portion 25b extending horizontally to cover the upper ends 40 of the multiple water pipes 4, and a tip end cylindrical portion 25c extending upward from the inner edge of the horizontal connecting portion 25b. Here, the base end (lower end) of the tip end cylindrical portion 25c is located below the upper end of the downdraft pipe 7, and the tip (upper end) extends to the vicinity of the top wall portion 22. In this way, the partition wall 25 as a whole is formed in a cylindrical shape such that the upper part of the first storage space S1 is narrower than the lower part of the first storage space S1.

[0026] The baffle plate 26 is positioned above the storage space S and is positioned to cover a portion of the first storage space S1 and the second storage space S2. It is configured to separate water droplets contained in steam that flows into the first storage space S1 from inside the water pipe 4 by colliding with the baffle plate 26 and to guide the water droplets to the second storage space S2. Specifically, the baffle plate 26 is formed in the shape of a disc with a circular through hole in the center, is positioned horizontally, has its inner side in contact with the inner wall portion 23, and its outer side extends beyond the position above the partition wall 25 to the vicinity of the outer wall portion 24.

[0027] 3. Effects (1) In the boiler 1 according to this embodiment, the partition wall 25 is configured to divide the storage space S into a first storage space S1 and a second storage space S2, and the baffle plate 26 is configured to separate water droplets contained in steam by causing steam flowing into the first storage space S1 from inside the water tube 4 to collide with the baffle plate 26 and guide the water droplets to the second storage space S2. With this configuration, bubbles do not accumulate in the second storage space S2 connected to the downcomer pipe 7, thereby suppressing a decrease in the hydrostatic pressure in the storage space S (second storage space S2) and making it possible to increase the amount of water precipitation from the downcomer pipe 7 of the upper header water.

[0028] (2) The partition wall 25 of this embodiment is configured to partition the storage space S such that the first storage space S1 is adjacent to the first opening 21a of the bottom wall portion 21 of the upper header 2 and the inner wall portion 23 of the upper header 2, and the second storage space S2 is adjacent to the second opening 24a and the outer wall portion 24. With this configuration, it is possible to efficiently arrange the first storage space S1 and the second storage space S2 in a boiler 1 equipped with an annular upper header 2.

[0029] (3) In this embodiment, the baffle plate 26 has its inner side in contact with the inner wall portion 23, and its outer side extends beyond the position above the partition wall 25 to the vicinity of the outer wall portion 24. With this configuration, steam rising through the first storage space S1 is reliably made to collide with the baffle plate 26, and the steam is guided toward the outer wall portion 24 and made to collide with the outer wall portion 24, thereby effectively promoting steam-water separation.

[0030] (4) The partition wall 25 in this embodiment is formed in a cylindrical shape such that its upper part is narrower than the lower part of the first storage space S1. With this configuration, the area of ​​the second storage space S2 can be secured widely while the first storage space S1 is adjacent to a plurality of first openings 21a at its lower part. By securing a wide area of ​​the second storage space S2, it is possible to suppress fluctuations in the water level of the upper header water.

[0031] In addition, by configuring the first storage space S1 so that the upper part is narrower than the lower part, it is possible to increase the flow velocity and cause the steam to collide with the baffle plate 26, thereby promoting steam-liquid separation. In this way, by promoting steam-liquid separation with the partition wall 25 and baffle plate 26 in the upper header 2, it is possible to prevent the supply of steam with a low degree of dryness to each piece of equipment via the steam outlet pipe 20, even in a separator-less boiler.

[0032] (5) However, if the electrical conductivity of the boiler water in the water pipe 4 increases due to concentration or other reasons, the viscosity increases and foaming becomes more intense, making it easier for water to be carried out to the upper header 2 along with the steam, which may result in the supply of steam with a low degree of dryness. Therefore, it is conceivable to install an electrical conductivity meter and supply water according to the change in electrical conductivity measured by the electrical conductivity meter to control the water level in accordance with the electrical conductivity. However, even in this case, there is a risk that the water level control according to the electrical conductivity may not be performed appropriately due to a malfunction of the electrical conductivity meter or other reasons.

[0033] In this regard, in the boiler 1 of this embodiment, when the electrical conductivity increases, the pressure loss due to two-phase flow increases in the first storage space S1 connected to the water tube 4, causing the boiler water level to automatically drop relative to the water level detected by the water level detection means 8. As a result, it is possible to lower the boiler water level without performing any special water level control that takes electrical conductivity into consideration, thereby preventing the supply of steam with a low dryness.

[0034] 4. Variations Furthermore, the present invention can also be implemented in the following embodiments.

[0035] In the above embodiment, the partition wall 25 was configured to include a base end cylindrical portion 25a supported by the bottom wall portion 21 and tapering upward, a horizontal connecting portion 25b extending horizontally to cover the upper ends 40 of the multiple water pipes 4, and a tip end cylindrical portion 25c extending upward from the inner edge of the horizontal connecting portion 25b. However, as shown in Modification 1 of Figure 3A, the partition wall 25 can also be made into a frustoconical shape that tapers upward. Even with such a configuration, the area of ​​the second storage space S2 can be made wider while keeping the first storage space S1 adjacent to the first opening 21a at its lower part. By making the area of ​​the second storage space S2 wider, it is possible to suppress fluctuations in the water level of the upper header water.

[0036] In the above embodiment, the baffle plate 26 extended beyond the position above the partition wall 25 to the vicinity of the outer wall portion 24. However, as shown in Modification 2 of Figure 3B, the baffle plate 26 only needs to extend to the position of the partition wall 25 at a minimum. Even with this configuration, the baffle plate 26 covers the first storage space S1, causing the steam flowing into the first storage space S1 from inside the water pipe 4 to collide with it, making it possible to separate the gas and liquid.

[0037] In the above embodiment, the upper header 2 was formed in a hollow annular shape, but the upper header 2 does not have to be annular. Even if it is not annular, it is possible to increase the amount of water precipitation from the upper header water downpipe 7 by providing a partition wall 25 that divides the storage space S into a first storage space S1 connected to the water pipe 4 and a second storage space S2 connected to the downpipe 7, and a baffle plate 26 that causes steam flowing into the first storage space S1 to collide with the baffle plate and guides water droplets to the second storage space S2.

[0038] [Contribution to the United Nations-led Sustainable Development Goals (SDGs)] This disclosure also includes matters that contribute to achieving Sustainable Development Goals (SDGs) Goal 12, "Responsible Consumption and Production," and Goal 13, "Take urgent action to combat climate change." [Explanation of Symbols]

[0039] 1: Boiler 2: Top Header 3: Bottom Header 4: Water pipe 4A:Inner water tube group 4B:Outer water tube group 5:Can body 6: Burner 7: Downpipe 8: Water level detection means 9: Control means 10: Boiler enclosure 20: Steam outlet pipe 21: Bottom wall 21a: 1st opening 22: Top and Wall Section 23: Interior wall section 24: External wall part 24a: 2nd opening 25: Partition wall 25a: Proximal tube part 25b: Horizontal connection section 25c: Tip side cylinder part 26: Baffle plate 30: Check valve 31: Water supply pump 32: Water supply line 33: Drain valve 34: Drainage line 40: Upper end 41: Bottom end 60: Fuel supply line 61: Fuel supply valve 62: Combustion chamber 63: Exhaust passage 80: Water level control cylinder 81: Upper communication pipe 82:Lower communication pipe 83: Electrode rod 83L :L rod 83S :S bar S: Storage space S1: First storage space S2: Second storage space

Claims

1. Water pipes and A lower header is located below the water pipe and connects to the lower end of the water pipe, An upper header is positioned above the water pipe and connected to the upper end of the water pipe, A boiler comprising a lower header and a lower header, the lower header and the upper header being connected by a downpipe, The aforementioned upper header comprises a partition wall and a baffle plate. The partition wall is configured to divide the storage space in the upper header where the upper header water is stored into a first storage space connected to the water pipe and a second storage space connected to the downpipe. A boiler in which the baffle plate is positioned above the storage space and positioned to cover at least the first storage space, and is configured to separate water droplets contained in steam by causing steam flowing into the first storage space from the water tube to collide with the baffle plate and guide the water droplets to the second storage space.

2. A boiler according to claim 1, Multiple water pipes are arranged vertically and in a ring shape, with a burner positioned at the center. The upper header is formed in a hollow annular shape along the upper ends of the plurality of water pipes, and has a plurality of first openings in its bottom wall portion for connecting to the plurality of water pipes, and a second opening in its outer wall portion for connecting to the downspout pipe. A boiler in which the partition wall is configured to partition the storage space such that the first storage space is adjacent to the plurality of first openings and the inner wall portion of the upper header, and the second storage space is adjacent to the second opening and the outer wall portion.

3. A boiler according to claim 2, A boiler in which the baffle plate has its inner side in contact with the inner wall and its outer side extending beyond the upper part of the partition wall to the vicinity of the outer wall.

4. A boiler according to claim 2 or claim 3, A boiler in which the partition wall is formed such that the upper part of the first storage space is narrower than the lower part of the first storage space.

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