Electrode type boiler

Abstract

To suppress corrosion of electrodes.SOLUTION: An electrode type boiler 1 includes: a water pipe 2; at least a pair of electrodes 6 disposed inside of the water pipe 2; and a water supply line 8 connected to an upper part of the water pipe 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to an electrode boiler. [Background technology]

[0002] In the technical field related to boilers, an electrode-type boiler such as that disclosed in Patent Document 1 is known. In an electrode-type boiler, a voltage is input between a pair of electrodes immersed in water, causing a current to flow through the water. When a current flows through the water, Joule heat is generated due to the electrical resistance of the water. The Joule heat raises the temperature of the water, generating steam. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Patent Application Publication No. 107238068 Summary of the Invention [Problem to be solved by the invention]

[0004] In an electrode boiler, when the electrodes are placed inside the water tubes, the water supplied to the water tubes evaporates at the top of the water tubes. As the water evaporates, the water may become concentrated at the top of the water tubes. If the water becomes concentrated at the top of the water tubes and the concentration of electrolytes dissolved in the water increases, the top of the electrodes may corrode.

[0005] The technology disclosed in this specification aims to suppress electrode corrosion. [Means for solving the problem]

[0006] This specification discloses an electrode boiler, which includes a water tube, at least a pair of electrodes disposed inside the water tube, and a water supply line connected to an upper portion of the water tube. [Effects of the Invention]

[0007] According to the technology disclosed in this specification, corrosion of the electrodes is suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front view schematically showing an electrode boiler according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view that schematically shows an electrode boiler according to an embodiment. [Figure 3] FIG. 3 is a cross-sectional view schematically showing a part of the electrode boiler according to the embodiment. [Figure 4] FIG. 4 is a perspective view schematically showing an electrode and a neutral electrode tube according to the embodiment. [Figure 5] FIG. 5 is a vertical cross-sectional view schematically showing a part of an electrode boiler according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the embodiments, a three-dimensional Cartesian coordinate system is defined, and the positional relationship of each part will be described with reference to the three-dimensional Cartesian coordinate system. The direction parallel to the X axis in a horizontal plane is defined as the X-axis direction. The direction parallel to the Y axis in a horizontal plane that is perpendicular to the X axis is defined as the Y-axis direction. The direction parallel to the Z axis that is perpendicular to the horizontal plane is defined as the Z-axis direction. The Z-axis direction is the up-down direction. The +Z side is the upper side, and the -Z side is the lower side.

[0010] [Electrode type boiler] Fig. 1 is a front view schematically showing an electrode boiler 1 according to an embodiment. Fig. 2 is a cross-sectional view schematically showing the electrode boiler 1 according to an embodiment. Fig. 3 is a cross-sectional view schematically showing a part of the electrode boiler 1 according to an embodiment.

[0011] As shown in Figures 1, 2, and 3, the electrode boiler 1 includes a water tube 2, a lower header 3, an upper header 4, an uprising pipe 5, an electrode 6, a neutral electrode tube 7, a feedwater line 8, a feedwater pump 9, a drain line 10, a drain valve 11, a steam line 12, a separator 13, and a downflow line 14.

[0012] The water pipe 2 is a cylindrical member having a water flow path. Water is stored in the water pipe 2. The water pipe 2 is long in the Z-axis direction. Multiple water pipes 2 are arranged. Each of the multiple water pipes 2 is arranged so that the central axis of the water pipe 2 is parallel to the Z-axis. The multiple water pipes 2 are arranged at intervals in the X-axis direction.

[0013] The lower header 3 communicates with the lower ends of the plurality of water pipes 2 .

[0014] The upper header 4 communicates with the upper ends of the plurality of water pipes 2. The upper header 4 communicates with the upper ends of the water pipes 2 via riser pipes 5.

[0015] The riser pipe 5 connects the top of the water pipe 2 to the bottom of the upper header 4. The riser pipe 5 has a steam flow path. The riser pipe 5 circulates the steam generated in the water pipe 2. The steam generated in the water pipe 2 is supplied to the upper header 4 via the riser pipe 5.

[0016] The upper header 4 receives steam supplied from the water pipes 2 via the riser pipes 5. The upper header 4 collects the steam supplied from each of the multiple riser pipes 5.

[0017] The electrodes 6 are arranged inside each of the multiple water tubes 2. The electrodes 6 are rod-shaped. The electrodes 6 are long in the vertical direction. In a plane perpendicular to the central axis of the water tubes 2, the outer shape of the electrodes 6 is circular. That is, the electrodes 6 are cylindrical and long in the Z-axis direction. The central axis of the electrodes 6 is parallel to the Z-axis. At least one pair of electrodes 6 is arranged inside each water tube 2. In this embodiment, three electrodes 6 are arranged inside each water tube 2. The three electrodes 6 are arranged parallel to each other inside the water tube 2. The three electrodes 6 are arranged so as to be spaced apart from each other inside the water tube 2. The dimensions of the three electrodes 6 are equal to each other. The dimensions of the electrodes 6 include the diameter (thickness) of the electrodes 6 and the dimension (length) in the Z-axis direction. The positions of the three electrodes 6 in the Z-axis direction are equal to each other.

[0018] 2 and 3, the electrodes 6 include a first electrode 6U, a second electrode 6V, and a third electrode 6W. In a plane perpendicular to the central axis of the water pipe 2, the three electrodes 6 (6U, 6V, 6W) are arranged at the vertices of an imaginary equilateral triangle. In the plane perpendicular to the central axis of the water pipe 2, the distance between the first electrode 6U and the second electrode 6V, the distance between the second electrode 6V and the third electrode 6W, and the distance between the third electrode 6W and the first electrode 6U are equal.

[0019] Three electrodes 6 are immersed in water inside the water tube 2. The electrodes 6 are in contact with the water inside the water tube 2. A voltage is input to the electrodes 6 immersed in the water. When a voltage is input to the electrodes 6, a current flows through the water contained in the water tube 2. When a current flows through the water, Joule heat is generated due to the electrical resistance of the water. The Joule heat causes the temperature of the water to rise, generating steam.

[0020] A neutral electrode tube 7 is disposed around each of the three electrodes 6. The neutral electrode tube 7 is made of metal. An example of a metal that forms the neutral electrode tube 7 is iron. Three neutral electrode tubes 7 are disposed inside one water tube 2. Inside one water tube 2, each of the three neutral electrode tubes 7 is connected to each other. Inside one water tube 2, each of the three neutral electrode tubes 7 is in contact with each other.

[0021] The neutral electrode tube 7 is cylindrical and arranged around the electrode 6. The neutral electrode tube 7 is long in the vertical direction. The central axis of the neutral electrode tube 7 is parallel to the Z axis. The three neutral electrode tubes 7 are arranged parallel to each other inside the water tube 2. The three neutral electrode tubes 7 are arranged so as to be in contact with each other inside the water tube 2. The dimensions of the three neutral electrode tubes 7 are equal to each other. The dimensions of the neutral electrode tube 7 include the diameter (thickness) of the neutral electrode tube 7 and the dimension (length) in the Z axis direction. The positions of the three neutral electrode tubes 7 are equal to each other in the Z axis direction.

[0022] 2 and 3, the neutral electrode tube 7 includes a first neutral electrode tube 7U arranged around the first electrode 6U, a second neutral electrode tube 7V arranged around the second electrode 6V, and a third neutral electrode tube 7W arranged around the third electrode 6W. In a plane perpendicular to the central axis of the water tube 2, the first neutral electrode tube 7U and the second neutral electrode tube 7V are in contact, the second neutral electrode tube 7V and the third neutral electrode tube 7W are in contact, and the third neutral electrode tube 7W and the first neutral electrode tube 7U are in contact.

[0023] The electrode 6 is disposed at the center of the neutral electrode tube 7. That is, the central axis of the electrode 6 coincides with the central axis of the neutral electrode tube 7. If the distance between the outer peripheral surface of the electrode 6 and the inner peripheral surface of the neutral electrode tube 7 in the radial direction of the central axis of the electrode 6 is defined as the radial distance, the radial distance is constant in the circumferential direction of the central axis of the electrode 6.

[0024] The three neutral electrode tubes 7 are immersed in water inside the water tube 2. The lower ends of the neutral electrode tubes 7 are positioned at the same height as the lower ends of the electrodes 6. The lower ends of the neutral electrode tubes 7 may also be positioned lower than the lower ends of the electrodes 6. The water in the water tubes 2 flows into the space between the outer peripheral surfaces of the electrodes 6 and the inner peripheral surface of the neutral electrode tubes 7.

[0025] In this embodiment, the three electrodes 6 form a star connection with the neutral electrode tube 7 as the neutral point. As shown in FIG.

[0026] The water supply line 8 is connected to the upper part of the water pipe 2. The water supply line 8 is connected to the upper part of each of the multiple water pipes 2. Water is supplied to the water supply line 8 from a water supply source (not shown). The water from the water supply source is supplied to the upper part of the water pipe 2 via the water supply line 8.

[0027] The water supply pump 9 is disposed in the water supply line 8. The water supply pump 9 drives the water from the water supply source to be supplied to the upper part of the water pipe 2 via the water supply line 8.

[0028] A drain line 10 is connected to the lower part of the lower header 3. The water in the lower header 3 is discharged from the lower header 3 through the drain line 10.

[0029] A drain valve 11 is disposed in the drain line 10. When the drain valve 11 is opened, the water in the lower header 3 is discharged through the drain line 10. When the drain valve 11 is closed, the discharge of water from the lower header 3 is stopped.

[0030] The steam line 12 is connected to the top of the upper header 4. The steam in the upper header 4 is discharged from the upper header 4 through the steam line 12.

[0031] The separator 13 is disposed in the steam line 12. The separator 13 separates the steam from the upper header 4 into steam and water.

[0032] The downflow line 14 connects the separator 13 to the lower header 3. The water separated by the separator 13 is returned from the downflow line 14 to the water pipe 2 via the lower header 3. The gas (steam) separated by the separator 13 is supplied to steam-using equipment.

[0033] In this embodiment, four water tubes 2 are provided. A first electrode 6U is disposed in each of the four water tubes 2. A second electrode 6V is disposed in each of the four water tubes 2. A third electrode 6W is disposed in each of the four water tubes 2. As shown in FIG. 2 , the four first electrodes 6U are connected in parallel to a power supply circuit 17. The four second electrodes 6V are connected in parallel to the power supply circuit 17. The four third electrodes 6W are connected in parallel to the power supply circuit 17.

[0034] When a voltage is input to the three electrodes 6 (6U, 6V, 6W) by the power supply circuit 17, a current flows through the water between the electrodes 6 and the neutral electrode tube 7 arranged around the electrodes 6. When a current flows through the water, Joule heat is generated due to the electrical resistance of the water. The Joule heat raises the temperature of the water, generating steam.

[0035] In this embodiment, the three electrodes 6 form a star connection with the neutral electrode tube 7 as the neutral point. Therefore, in a cross section perpendicular to the central axis of the water tube 2, current flows between the neutral electrode tube 7 and all parts of the outer surface of the electrode 6. For example, if the three electrodes 6 form a delta connection, current flows along the shortest route between a pair of adjacent electrodes. In this case, current is output from only a part of the outer surface of the electrode 6 in a cross section perpendicular to the central axis of the water tube 2. Because only a part of the outer surface of the electrode 6 contributes to the generation of Joule heat, it becomes difficult to efficiently raise the temperature of the water. In this embodiment, the three electrodes 6 form a star connection with the neutral electrode tube 7 as the neutral point. Therefore, the entire outer surface of the electrode 6 contributes to the generation of Joule heat. Therefore, the electrode-type boiler 1 can efficiently raise the temperature of the water.

[0036] FIG. 4 is a perspective view schematically illustrating an electrode 6 and a neutral electrode tube 7 according to an embodiment. As shown in FIG. 4, in the embodiment, the inner surface (inner peripheral surface) of the neutral electrode tube 7 is connected to the outer surface (outer peripheral surface) of the neutral electrode tube 7. The neutral electrode tube 7 has a plurality of openings 18 penetrating the inner and outer surfaces of the neutral electrode tube 7. In the example shown in FIG. 4, the openings 18 are circular. In the example shown in FIG. 4, the neutral electrode tube 7 includes a punched metal formed into a tubular shape. The openings 18 may be slit-shaped.

[0037] Air bubbles may be generated between the electrode 6 and the neutral electrode tube 7. If air bubbles exist between the electrode 6 and the neutral electrode tube 7, the flow of current between the electrode 6 and the neutral electrode tube 7 may be obstructed. In the embodiment, the inner surface of the neutral electrode tube 7 is in communication with the outer surface of the neutral electrode tube 7, so that air bubbles existing between the electrode 6 and the neutral electrode tube 7 are disposed outside the neutral electrode tube 7 through the opening 18. Water surrounding the neutral electrode tube 7 can flow between the electrode 6 and the neutral electrode tube 7 through the opening 18.

[0038] 5 is a longitudinal cross-sectional view schematically showing a portion of an electrode boiler 1 according to an embodiment. As shown in FIG. 5, the upper end of the electrode 6 is disposed above the upper end of the neutral electrode tube 7. As described above, the water supply line 8 is connected to the upper part of the water tube 2. The upper end of the neutral electrode tube 7 is disposed below the connection between the water supply line 8 and the water tube 2. Water from the water supply line 8 is supplied from the upper end of the neutral electrode tube 7 to the periphery of the electrode 6.

[0039] In this embodiment, the water supply line 8 is connected to the upper part of the water pipe 2, and water from the water supply line 8 is supplied to the upper part of the water pipe 2, thereby preventing water from concentrating in the upper part of the water pipe 2. The water supplied to the inside of the water pipe 2 from the water supply line 8 flows from the upper part to the lower part of the water pipe 2, and therefore, sufficient convection of water occurs inside the water pipe 2, preventing localized concentration of water in the upper part of the water pipe 2. Since localized concentration of water in the upper part of the water pipe 2 is prevented and a local increase in the concentration of electrolytes dissolved in water is prevented, corrosion of the upper part of the electrode 6 is prevented.

[0040] [effect] As described above, the electrode boiler 1 includes the water tube 2, at least one pair of electrodes 6 disposed inside the water tube 2, and the water supply line 8 connected to the upper part of the water tube 2. According to the embodiment, water from the water supply line 8 is supplied to the upper part of the water tube 2, so that local concentration of water in the upper part of the water tube 2 is suppressed.

[0041] For example, when the water supply line 8 is connected to the lower header 3, the water supplied from the water supply line 8 to the lower header 3 flows from the bottom to the top of the water pipes 2. The water in the water pipes 2 evaporates in the top of the water pipes 2. When the water supplied to the water pipes 2 flows from the bottom to the top of the water pipes 2, the water is not sufficiently agitated in the top of the water pipes 2, and as the water evaporates, there is a high possibility that the water will become concentrated in the top of the water pipes 2. For example, when the voltage input to the electrode 6 is low, the water does not boil vigorously, and there is a high possibility that the water will not be sufficiently agitated in the top of the water pipes 2. As a result, there is a possibility that the water will become locally concentrated in the top of the water pipes 2.

[0042] According to the embodiment, water from the water supply line 8 is supplied to the upper part of the water pipe 2, and the water supplied to the upper part of the water pipe 2 flows from the upper part to the lower part of the water pipe 2. Because the water flows from the upper part to the lower part of the water pipe 2, there is sufficient convection of water inside the water pipe 2, and local concentration of water in the upper part of the water pipe 2 is suppressed. Local concentration of water in the upper part of the water pipe 2 is suppressed, and a local increase in the concentration of electrolytes dissolved in the water is suppressed, so corrosion of the upper part of the electrode 6 is suppressed.

[0043] In this embodiment, a plurality of water pipes 2 are arranged. The water supply line 8 is connected to the upper part of each of the plurality of water pipes 2. This prevents corrosion of the electrodes 6 arranged inside each of the plurality of water pipes 2.

[0044] In an embodiment, the water separated by the separator 13 is returned to the water pipe 2 via the downcomer line 14 and the lower header 3 .

[0045] In this embodiment, the upper end of the neutral electrode tube 7 is located below the connection between the water supply line 8 and the water pipe 2. Water from the water supply line 8 is supplied from the upper end of the neutral electrode tube 7 to the periphery of the electrode 6.

[0046] [Other embodiments] In the above-described embodiment, the neutral electrode tube 7 is cylindrical. However, the neutral electrode tube 7 does not have to be cylindrical. That is, in a plane perpendicular to the central axis of the water tube 2, the neutral electrode tube 7 does not have to be circular, but may be polygonal, such as rectangular or hexagonal.

[0047] [Contribution to the United Nations-led Sustainable Development Goals (SDGs)] This disclosure includes matters that contribute to achieving Goal 12 of the SDGs (Sustainable Development Goals), "Responsible Consumption and Production," and Goal 13, "Take urgent action to combat climate change." [Explanation of symbols]

[0048] 1...electrode boiler, 2...water tube, 3...lower header, 4...upper header, 5...riser pipe, 6...electrode, 6U...first electrode, 6V...second electrode, 6W...third electrode, 7...neutral electrode tube, 7U...first neutral electrode tube, 7V...second neutral electrode tube, 7W...third neutral electrode tube, 8...feedwater line, 9...feedwater pump, 10...drain line, 11...drain valve, 12...steam line, 13...separator, 14...downflow line, 17...power circuit, 18...opening.

Claims

1. Water pipes and At least one pair of electrodes disposed inside the water tube; a water supply line connected to an upper portion of the water pipe; Electrode boiler.

2. The water pipe is arranged in plurality, The water supply line is connected to an upper portion of each of the plurality of water pipes.

2. The electrode boiler according to claim 1.

3. a lower header communicating with lower ends of each of the plurality of water pipes; an upper header communicating with upper ends of each of the plurality of water pipes; a separator that separates steam from the upper header into steam and water; a downflow line connecting the separator and the lower header, 3. The electrode boiler according to claim 2.

4. The electrodes are arranged in three numbers, a neutral electrode tube disposed around each of the three electrodes; Each of the three neutral electrode tubes is interconnected; Water from the water supply line is supplied from the upper end of the neutral electrode tube to the periphery of the electrode.

2. The electrode boiler according to claim 1.

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