Rectification power supply system of direct-current submerged arc furnace

Abstract

The invention discloses a rectification power supply system for a direct-current submerged arc furnace. The rectification power supply system comprises a rectifier transformer unit, two groups of rectifier cabinet units, a secondary bus unit and an electrode unit, the two groups of rectifier cabinet units are respectively arranged on two sides of the rectifier transformer; the two groups of rectifier cabinet units and the low-voltage direct-current wire outlet copper bars of the rectifier transformer output wires on the same surface with equal-height cross sections; and the two groups of rectifier cabinet units and the low-voltage direct-current outlet copper bars of the rectifier transformer are connected with the electrode unit through the secondary bus unit. The secondary bus unit is connected with the lower part of the side surface of the rectifier cabinet unit at the back lower part of the rectifier transformer unit; the secondary bus unit is connected with the contact element of the electrode unit, so that the length of the connecting copper bar and the connecting copper pipe is shortest. The total length difference value of each group of secondary buses is minimum, and the load of the power supply system tends to be balanced; the once-through furnace project investment cost can be effectively reduced; and the transmission electric energy loss of smelting production is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of rectifier power supply systems and relates to a rectifier power supply system for a DC ore-fired furnace. Background Art

[0002] Currently, DC smelting technology, in which both positive and negative electrodes are arranged perpendicular to the furnace, is increasingly being used in industry. While some related smelting technologies are still under development, this arrangement of DC submerged arc furnaces has already shown initial success on existing production lines, offering significant energy-saving and environmental advantages. Compared to AC submerged arc furnaces, it offers advantages such as high power factor, no skin effect, flexible power transmission, and high arc temperature. Compared to bottom-electrode DC submerged arc furnaces, it offers advantages such as high thermal efficiency, high powder utilization, low failure rate, and easy maintenance. Because there is no bottom electrode consumption, regular bottom electrode overhaul is not required, ensuring continuous smelting production.

[0003] During the smelting process of an industrial ferroalloy smelting DC submerged arc furnace in which both the positive and negative electrodes are arranged vertically in the furnace, the transmission current from the low-voltage side of the rectifier device to the smelting electrodes is as high as 200kA or even greater, resulting in relatively large capacity of the rectifier transformer and rectifier cabinet. The rectifier output line is connected to the electrodes using multiple water-cooled flexible copper tubes in parallel, which is called the "short network" of the power supply system in the industry. The transmission current of each copper tube is about 20kA, which is a huge value. Copper busbars and water-cooled copper tubes of corresponding cross-sectional areas are required for power transmission. The equipment cost is relatively large, so a reasonable layout of the rectifier system equipment is crucial, which can save the investment cost of the project and save energy loss during the production process of the DC submerged arc furnace.

[0004] Therefore, we have developed a DC submerged arc furnace rectification power supply system, which can be used for the DC submerged arc furnace rectification system power supply layout, improve the overall operating efficiency of the DC submerged arc furnace, and save power transmission losses. Summary of the Invention

[0005] In order to solve the technical problem of the unreasonable arrangement of the DC ore-fired furnace rectification power supply system, the present invention adopts the following technical solution: a DC ore-fired furnace rectification power supply system, comprising: a rectifier transformer unit, two sets of rectifier cabinet units, a secondary bus unit and an electrode unit; Two groups of rectifier cabinet units are arranged on both sides of the rectifier transformer; The low-voltage DC outgoing copper busbars of the two sets of rectifier cabinet units and rectifier transformers should be on the same side with the same height and cross-section, and the connecting copper busbars should be as short as possible; The two groups of rectifier cabinet units and the low-voltage DC outgoing copper busbars of the rectifier transformer are connected to the electrode unit through the secondary bus unit.

[0006] Furthermore: when the vertical surface on the high-voltage incoming line side is taken as the front surface of the rectifier transformer unit, the neutral point on the low-voltage side of the rectifier transformer unit is connected to the outgoing copper busbar on the lower part of the back surface, which is opposite to the front surface; When the long side of the rectifier cabinet unit that is not opposite to the rectifier transformer unit is taken as the front side, the two sides adjacent to the front side of the rectifier transformer unit are the side sides of the rectifier transformer unit; The AC line on the low-voltage side of the rectifier transformer unit is directly connected to the upper side of the rectifier transformer unit at the same height as the back of the rectifier cabinet unit; The secondary busbar unit is connected to the lower part of the back of the rectifier transformer unit and the lower part of the side of the rectifier cabinet unit; The secondary busbar unit is connected to the contact elements of the electrode unit so that the length of the connecting copper bar and the connecting copper tube is minimized.

[0007] Further: the rectifier transformer unit includes a rectifier transformer unit body; High-voltage porcelain bottle: installed on the upper part of the rectifier transformer unit near the front, used to connect to the high-voltage incoming power supply; Junction box: It is located on the upper front of the rectifier transformer unit and is used for transformer signal convergence. High-voltage side neutral point: located on the upper part of the rectifier transformer unit near the front, used for connecting the neutral point grounding device; Oil tank: It is located on the upper part of the rectifier transformer unit near the back and is used to hold transformer cooling oil; Low-voltage side AC terminal block: Located on the upper side of the rectifier transformer unit body, it is used to connect to the secondary busbar unit. A copper plate is used to connect the two. The rectifier-side water-cooling hard copper tube of the secondary busbar unit is welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block with bolts. Low-voltage side neutral point terminal block: Located at the lower back of the rectifier transformer unit, it is used to connect to the secondary busbar unit. A copper plate is used to connect the two. The two rectifier-side water-cooled hard copper tubes of the secondary busbar unit are welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block with bolts.

[0008] Furthermore: the rectifier cabinet unit includes: Output positive water-cooled copper busbar: Arranged at equal intervals inside the rectifier cabinet unit and extending outside the cabinet, it is used to connect to the secondary busbar unit. Here, a copper plate is used to connect the output positive water-cooled copper busbar to the secondary busbar unit. The two rectifier-side water-cooled hard copper tubes of the secondary busbar unit are welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block with bolts. Output negative water-cooling copper busbar: Arranged at equal intervals inside the rectifier cabinet unit and extending outside the cabinet, it is used to connect to the secondary busbar unit. Here, a copper plate is used to connect the output negative water-cooling copper busbar to the secondary busbar unit. The two rectifier-side water-cooling hard copper tubes of the secondary busbar unit are welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block with bolts.

[0009] The low-voltage side neutral point terminal block, output positive water-cooling copper busbar, and output negative water-cooling copper busbar should be kept at the same height.

[0010] Input AC water-cooling copper busbars: They are arranged vertically in pairs at equal intervals inside the rectifier cabinet unit and are used to connect to the secondary busbar unit inside the cabinet. They are fixed to the hard busbars of the flexible copper busbars with bolts.

[0011] Furthermore: the secondary busbar unit includes a rectifier-side water-cooled hard copper tube, a water-cooled flexible copper tube, an electrode-side water-cooled hard copper tube and a contact element; one end of the rectifier-side water-cooled hard copper tube is connected to one end of the water-cooled flexible copper tube; the other end of the water-cooled flexible copper tube is connected to the electrode-side water-cooled hard copper tube; The contact elements are configured in 8 pieces for each electrode, and each piece is welded to two water-cooled hard copper tubes on the electrode side, used for one inlet and one outlet of the water channel; The contact elements on the positive electrode are numbered 1 and 9, those closest to the rectifier system; Contact elements 1-8 are numbered in a clockwise direction starting from number 1; Contact elements 9-16 are numbered counterclockwise starting from number 9; The numbering of the contact elements on the negative electrode is symmetrical to the numbering of the contact elements on the positive electrode; The low-voltage side neutral point terminal block of the rectifier transformer unit, the output positive water-cooled copper busbar of the rectifier cabinet unit, and the output negative water-cooled copper busbar of the rectifier cabinet unit are respectively connected to the contact elements of the electrode unit phases through the secondary bus unit.

[0012] Furthermore: the low-voltage side AC terminal blocks of the rectifier transformer unit and the input AC water-cooling copper busbars of the rectifier cabinet unit are named a1 to a8, b1 to b8, and c1 to c8 according to the coil groups. Similarly, the low-voltage side neutral point terminal blocks of the rectifier transformer unit are named O1 to O8, the output positive water-cooling copper busbars of the rectifier cabinet unit are named P1, P3, P5, and P7, and the output negative water-cooling copper busbars of the rectifier cabinet unit are named N2, N4, N6, and N8. The terminal blocks connecting the rectifier transformer unit and the rectifier cabinet unit with positive output polarity are a5, c3, a7, c1, b5, b3, b7, b1, c5, a3, c7, and a1 from the front to the side of the rectifier transformer unit. The terminal blocks connecting the rectifier transformer unit and the rectifier cabinet unit with negative output polarity are c8, a2, c6, a4, b8, b2, b6, b4, a8, c2, a6, and c4 from the front to the side of the rectifier transformer unit. The terminal block numbers of the output positive water-cooling copper busbar of the rectifier cabinet unit are P5, P3, P7, and P1 from the outside to the inside; The terminal block numbers of the output negative water-cooling copper busbar of the rectifier cabinet unit are N8, N2, N6, and N4 from the outside to the inside; Pipeline connections are made based on the principle of minimum total resistance deviation adopted by the secondary busbar unit; There are 32 contact elements in total. The positive electrodes are named J+1 to J+16, and the negative electrodes are named J-1 to J-16. When the secondary busbar unit is arranged, the connection is as follows: The lower copper tube of P5 is connected to the J+1 contact element, the upper copper tube of P5 is connected to the J+2 contact element, the lower copper tube of P3 is connected to the J+3 contact element, the upper copper tube of P3 is connected to the J+4 contact element, the lower copper tube of P7 is connected to the J+5 contact element, the upper copper tube of P7 is connected to the J+6 contact element, the lower copper tube of P1 is connected to the J+7 contact element, and the upper copper tube of P1 is connected to the J+8 contact element; the lower copper tube of O8 is connected to the J+9 contact element, the upper copper tube of O8 is connected to the J+10 contact element, the lower copper tube of O4 is connected to the J+11 contact element, the upper copper tube of O4 is connected to the J+12 contact element, the lower copper tube of O6 is connected to the J+13 contact element, the upper copper tube of O6 is connected to the J+14 contact element, the lower copper tube of O2 is connected to the J+15 contact element, and the upper copper tube of O2 is connected to the J+16 contact element; The lower copper tube of O1 is connected to the J-9 contact element, the upper copper tube of O1 is connected to the J-10 contact element, the lower copper tube of O5 is connected to the J-11 contact element, the upper copper tube of O5 is connected to the J-12 contact element, the lower copper tube of O3 is connected to the J-13 contact element, the upper copper tube of O3 is connected to the J-14 contact element, the lower copper tube of O7 is connected to the J-15 contact element, and the upper copper tube of O7 is connected to the J-16 contact element; the lower copper tube of N8 is connected to the J-1 contact element, the upper copper tube of N8 is connected to the J-2 contact element, the lower copper tube of N2 is connected to the J-3 contact element, the upper copper tube of N2 is connected to the J-4 contact element, the lower copper tube of N6 is connected to the J-5 contact element, the upper copper tube of N6 is connected to the J-6 contact element, the lower copper tube of N4 is connected to the J-7 contact element, and the upper copper tube of N4 is connected to the J-8 contact element.

[0013] The present invention provides a DC ore-fired furnace rectification power supply system, proposes a DC ore-fired furnace rectification power supply system, realizes the reasonable layout of the DC ore-fired furnace rectification power supply system, and provides an optimization solution for reducing costs and increasing efficiency in DC ore-fired furnace project production. It has the following advantages: The total length difference of each set of secondary busbars is minimized, and the load of the power supply system tends to be balanced; Can effectively reduce the investment cost of DC furnace projects; Reduce transmission power loss in smelting production. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 It is the layout diagram of the rectifier system; Figure 2 This is the side view of the DC outlet busbar; Figure 3 This is the schematic diagram of the rectifier system.

[0016] Figure numerals: 101, rectifier transformer unit, 102, rectifier cabinet unit, 103, secondary bus unit 104, electrode unit, 111, high-voltage porcelain bottle, 112, junction box, 113, high-voltage side neutral point, 114, oil tank, 115, low-voltage side AC terminal block, 116, low-voltage side neutral point terminal block, 121, output positive water-cooled copper busbar, 122, output negative water-cooled copper busbar, 123, input AC water-cooled copper busbar, 124, flexible connection copper busbar, 131, rectifier side water-cooled hard copper tube, 132, water-cooled flexible copper tube, 133, electrode side water-cooled hard copper tube, 134, copper tube insulation bracket, 135, contact element. DETAILED DESCRIPTION

[0017] It should be noted that, unless there is any conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] The DC ore-fired furnace rectifier power supply system includes: a rectifier transformer unit, two sets of rectifier cabinet units, a secondary bus unit and an electrode unit.

[0020] The two rectifier cabinet units are arranged on both sides of the rectifier transformer; The low-voltage DC outgoing copper busbars of the two rectifier cabinet units and the rectifier transformer should be on the same side with the same height and cross-section, and the flexible connection copper busbar 124 should be as short as possible; The two rectifier cabinet units and the low-voltage DC outgoing copper busbars of the rectifier transformer are connected to the electrode unit through the secondary bus unit.

[0021] The rectifier power supply system adopts a double reverse star-type in-phase anti-parallel structure. The two sets of rectifier cabinet units are arranged on both sides of the rectifier transformer. The low-voltage DC outgoing copper busbars are connected to the electrode unit through the secondary bus unit.

[0022] When the vertical surface on the high-voltage incoming line side is the front face of the rectifier transformer unit, the neutral point on the low-voltage side of the rectifier transformer unit is led out to the flexible copper bus 124 on the lower part of the back face, which is opposite to the front face; When the long side of the rectifier cabinet unit that is not opposite to the rectifier transformer unit is taken as the front side, the two sides adjacent to the front side of the rectifier transformer unit are the side sides of the rectifier transformer unit; The AC line on the low-voltage side of the rectifier transformer unit is directly connected to the upper side of the rectifier transformer unit and the water level on the back of the rectifier cabinet unit; The secondary busbar unit is connected to the lower part of the back of the rectifier transformer unit and the lower part of the side of the rectifier cabinet unit; The contact elements of the secondary busbar unit and the electrode unit are connected to minimize the length of the connecting copper tube to ensure the lowest total loss during system operation. The copper tubes include a rectifier-side water-cooled hard copper tube 131, a water-cooled flexible copper tube 132, and an electrode-side water-cooled hard copper tube 133. AC power is input from the high-voltage grid side of the rectifier transformer, which adjusts it to the voltage required for smelting. The valve side of the rectifier transformer is connected to the rectifier cabinet. The two rectifier cabinet units arranged on both sides of the rectifier transformer unit output four sets of positive copper bars and four sets of negative copper bars, respectively. Each set of copper bars and the neutral point of the rectifier transformer are connected to the positive and negative electrodes through water-cooled rigid copper tubes, water-cooled flexible copper tubes, and contact elements. Each rectifier transformer, its connected rectifier cabinet, secondary busbar, and positive and negative electrodes form a power supply system, and each power supply system is independently powered. Each DC submerged arc furnace is equipped with at least one power supply system. When two or more power supply systems are installed, the positive and negative electrodes are staggered within the furnace.

[0023] DC ore-fired furnace rectifier power supply system, such as Figure 1 Rectification system layout diagram, Figure 2 Side view of DC output busbar, Figure 3 As shown in the schematic diagram of the rectifier system, it consists of a rectifier transformer unit 101, a rectifier cabinet unit 102, a secondary bus unit 103 and an electrode unit 104; The rectifier transformer unit 101 is connected to the rectifier cabinet unit 102 via an AC flexible copper busbar 124, the rectifier transformer unit 101 is connected to the secondary busbar unit 103 via a copper plate, the rectifier cabinet unit 102 is connected to the secondary busbar unit 103 via a copper plate, and the side of the contact element 135 in the secondary busbar unit 103 is connected to the electrode unit 104 via an external compression spring with an arc-shaped contact surface under fixed pressure.

[0024] The rectifier transformer unit includes a rectifier transformer unit body; High-voltage porcelain bottle 111: arranged at the upper part of the main body of the rectifier transformer unit 101 near the front, used for connecting to the high-voltage incoming power supply.

[0025] The junction box 112 is provided on the upper front portion of the main body of the rectifier transformer unit 101 and is used for transformer signal aggregation.

[0026] The high-voltage side neutral point 113 is arranged at the upper part of the main body of the rectifier transformer unit 101 near the front, and is used for connecting the neutral point grounding device.

[0027] The oil tank 114 is provided at the upper portion of the main body of the rectifier transformer unit 101 near the back, and is used to contain transformer cooling oil.

[0028] Low-voltage side AC terminal block 115: It is set on the upper side of the main body of the rectifier transformer unit 101 and is used to connect to the secondary bus unit 103. A copper plate is used here to connect the low-voltage side AC terminal block 115 to the secondary bus unit 103. The rectifier side water-cooled hard copper tube 131 of the secondary bus unit 103 is welded to the copper plate, and holes are punched in the copper plate to fix it to the low-voltage side AC terminal block 115 with bolts.

[0029] Low-voltage side neutral point terminal block 116: It is set at the lower back of the main body of the rectifier transformer unit 101 and is used to connect to the secondary bus unit 103. A copper plate is used here to connect the low-voltage side neutral point terminal block 116 to the secondary bus unit 103. The two rectifier side water-cooled hard copper tubes 131 of the secondary bus unit 103 are welded to the copper plate, and holes are punched in the copper plate to fix it to the low-voltage side AC terminal block 115 with bolts.

[0030] The rectifier cabinet unit includes: Output positive water-cooled copper busbar 121: Arranged at equal intervals inside the rectifier cabinet unit 102 and extending outside the cabinet, it is used to connect to the secondary busbar unit 103. Here, a copper plate is used to connect the output positive water-cooled copper busbar 121 to the secondary busbar unit 103. The two rectifier-side water-cooled hard copper tubes 131 of the secondary busbar unit 103 are welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block 115 with bolts.

[0031] Output negative water-cooled copper busbar 122: Arranged at equal intervals inside the rectifier cabinet unit 102 and extending outside the cabinet, it is used to connect to the secondary busbar unit 103. Here, a copper plate is used to connect the output negative water-cooled copper busbar 122 to the secondary busbar unit 103. The two rectifier-side water-cooled hard copper tubes 131 of the secondary busbar unit 103 are welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block 115 with bolts. Figure 2 As shown, the low-voltage side neutral point terminal block 116, the output positive water-cooling copper busbar 121, and the output negative water-cooling copper busbar 122 are kept at the same level.

[0032] Input AC water-cooling copper busbars 123: Arranged vertically in pairs with equal spacing inside the rectifier cabinet unit 102, such as Figure 1 and Figure 2 As shown, it is used to connect with the secondary busbar unit 103 in the cabinet and is fixed to the hard busbar of the flexible connection copper busbar 124 by bolts.

[0033] Flexible copper busbar 124: The middle section is made of multiple sheets of 1.0 mm thick copper foil stacked together to ensure flexibility on the side. The hard copper busbars at both ends have holes, and the copper foil and the hard copper busbar are connected by welding.

[0034] Secondary busbar unit 103: includes rectifier-side water-cooled hard copper tube 131, water-cooled flexible copper tube 132, electrode-side water-cooled hard copper tube 133, copper tube insulation bracket 134 and contact element 135; One end of the rectifier-side water-cooled hard copper tube 131 is connected to one end of the water-cooled flexible copper tube 132; the other end of the water-cooled flexible copper tube 132 is connected to the electrode-side water-cooled hard copper tube 133; The rectifier side water-cooled hard copper tubes 131 are symmetrically centered around the rectifier transformer unit 101, and each rectifier cabinet unit is provided with four water-cooled hard copper tubes. The positive electrode and negative electrode are each provided with 8 hard copper tubes, which are symmetrically arranged, with every four hard copper tubes being symmetrically arranged; The copper tube insulating bracket 134 is provided at the end of the rectifier-side water-cooled hard copper tube 131 for support; Copper tube insulation brackets 134 are also provided at the ends of the water-cooled flexible copper tubes 132 for support; The contact elements 135 are configured in eight pieces for each electrode, and each piece is welded to two electrode-side water-cooled hard copper tubes 133, serving as one inlet and one outlet for the water channel. The contact elements on the positive electrode are numbered 1 and 9, those closest to the rectifier system; Contact elements 1-8 are numbered in a clockwise direction starting from number 1; Contact elements 9-16 are numbered counterclockwise starting from number 9; The numbering of the contact elements on the negative electrode is mirror-symmetrical to the numbering of the contact elements on the positive electrode; Figure 3 As shown; The low-voltage side neutral point terminal block 116 of the rectifier transformer unit, the output positive water-cooled copper busbar 121 of the rectifier cabinet unit 102, and the output negative water-cooled copper busbar 122 of the rectifier cabinet unit 102 are connected one by one to the contact elements of the electrode unit 104 through the secondary bus unit. The rectifier transformer unit 101 utilizes a fixed-coil configuration with an on-load tap changer. The primary side of the main transformer utilizes a zigzag phase-shifting scheme, with the phase-shift angle varying according to the number of pole pairs. For a four-pole, two-unit system, the phase-shift angles for the 1# main transformer are +7.5° and -22.5°, while those for the 2# main transformer are -7.5° and +22.5°. This reduces the impact of the rectifier system on the grid and harmonics in the power supply system. The secondary side of the main transformer utilizes a double-reverse star-type, in-phase, anti-parallel structure to eliminate DC magnetization of the iron core and improve the power factor of the rectifier system. A three-phase, five-leg iron core structure reduces iron core material consumption compared to structures with balancing reactors.

[0035] like Figure 3 As shown, according to the principle of the rectifier system, the output terminals of each group of coils are named and numbered. In order to reduce confusion, the low-voltage side AC terminal block 115 of the rectifier transformer unit 101 and the input AC water-cooling copper busbar 123 of the rectifier cabinet unit 102 are named a1 to a8, b1 to b8, c1 to c8 according to the coil group. Similarly, the low-voltage side neutral point terminal block 116 of the rectifier transformer unit 101 is named O1 to O8, the output positive water-cooling copper busbar 121 of the rectifier cabinet unit 102 is named P1, P3, P5, P7, and the output negative water-cooling copper busbar 122 of the rectifier cabinet unit 102 is named N2, N4, N6, N8. like Figure 1 As shown, according to Figure 3 The terminals of the rectifier transformer unit 101 are numbered according to the principle. The terminal blocks connecting the rectifier transformer unit 101 with the rectifier cabinet unit 102 with positive output are a5, c3, a7, c1, b5, b3, b7, b1, c5, a3, c7, and a1, respectively, from the front to the side of the rectifier transformer unit 101. The terminal blocks connecting the rectifier transformer unit 101 with the rectifier cabinet unit 102 with negative output are c8, a2, c6, a4, b8, b2, b6, b4, a8, c2, a6, and c4, respectively, from the front to the side of the rectifier transformer unit 101. The terminal blocks of the positive output water-cooling copper busbar 121 of the rectifier cabinet unit 102 are numbered P5, P3, P7, and P1, respectively, from the outside to the inside. The terminal blocks of the negative output water-cooling copper busbar 122 of the rectifier cabinet unit 102 are numbered N8, N2, N6, and N4, respectively, from the outside to the inside.

[0036] Because the total length of each group of copper tubes in the secondary busbar unit 103 is different, and considering that the charge resistance between the positive pole number 12 and the negative pole number 12, and the positive pole number 13 and the negative pole number 13 of the contact element 135 is the smallest during the production process, the principle of minimum total resistance deviation is adopted for pipe connection. There are 32 numbers in total for the contact elements 135, and the ones corresponding to the positive electrodes are named J+1 to J+16, and the ones corresponding to the positive electrodes are named J-1 to J-16. When the secondary busbar unit 103 is arranged, the connections are as follows: the lower copper tube of P5 is connected to the J+1 contact element, the upper copper tube of P5 is connected to the J+2 contact element, the lower copper tube of P3 is connected to the J+3 contact element, the upper copper tube of P3 is connected to the J+4 contact element, the lower copper tube of P7 is connected to the J+5 contact element, the upper copper tube of P7 is connected to the J+6 contact element, the lower copper tube of P1 is connected to the J+7 contact element, and the upper copper tube of P1 is connected to the J+8 contact element. The contact elements are connected; the lower copper tube of O8 is connected to the J+9 contact element, the upper copper tube of O8 is connected to the J+10 contact element, the lower copper tube of O4 is connected to the J+11 contact element, the upper copper tube of O4 is connected to the J+12 contact element, the lower copper tube of O6 is connected to the J+13 contact element, the upper copper tube of O6 is connected to the J+14 contact element, the lower copper tube of O2 is connected to the J+15 contact element, and the upper copper tube of O2 is connected to the J+16 contact element; The lower copper tube of O1 is connected to the J-9 contact element, the upper copper tube of O1 is connected to the J-10 contact element, the lower copper tube of O5 is connected to the J-11 contact element, the upper copper tube of O5 is connected to the J-12 contact element, the lower copper tube of O3 is connected to the J-13 contact element, the upper copper tube of O3 is connected to the J-14 contact element, the lower copper tube of O7 is connected to the J-15 contact element, and the upper copper tube of O7 is connected to the J-16 contact element; the lower copper tube of N8 is connected to the J-1 contact element, the upper copper tube of N8 is connected to the J-2 contact element, the lower copper tube of N2 is connected to the J-3 contact element, the upper copper tube of N2 is connected to the J-4 contact element, the lower copper tube of N6 is connected to the J-5 contact element, the upper copper tube of N6 is connected to the J-6 contact element, the lower copper tube of N4 is connected to the J-7 contact element, and the upper copper tube of N4 is connected to the J-8 contact element.

[0037] The designed and developed DC ore-bearing furnace rectifier power supply system has rectifier cabinet units 102 arranged on both sides of the rectifier transformer unit 101 with different positive and negative polarities. The whole is connected to the smelting electrodes with DC outgoing lines at equal heights. It has a secondary busbar unit 103 structure with the shortest length. The power supply system load tends to be balanced, which can effectively reduce the investment cost of the DC furnace project and reduce the transmission power loss in the smelting production.

[0038] The DC ore-bearing furnace rectifier power supply system developed this time realizes the optimized layout of the rectifier system. The rectifier cabinet units are arranged on both sides of the rectifier transformer unit with different positive and negative polarities. The whole system is connected to the smelting electrodes with DC outgoing lines of equal height. It has a secondary busbar unit structure with the shortest length. The power supply system load tends to be balanced, which can effectively reduce the investment cost of the DC furnace project and reduce the transmission power loss in the smelting production.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A DC ore-fired furnace rectification power supply system, characterized by: include: Rectifier transformer unit, two sets of rectifier cabinet units, secondary bus unit and electrode unit; Two groups of rectifier cabinet units are arranged on both sides of the rectifier transformer; The low-voltage DC outgoing copper busbars of the two sets of rectifier cabinet units and rectifier transformers should be on the same side with the same height and cross-section, and the connecting copper busbars should be as short as possible; The two groups of rectifier cabinet units and the low-voltage DC outgoing copper busbars of the rectifier transformer are connected to the electrode unit through the secondary bus unit.

2. A DC ore-bearing furnace rectification power supply system according to claim 1, characterized in that: When the vertical surface on the high-voltage incoming line side is taken as the front of the rectifier transformer unit, the neutral point on the low-voltage side of the rectifier transformer unit is connected to the outgoing copper bus at the lower part of the back, which is opposite to the front. When the long side of the rectifier cabinet unit that is not opposite to the rectifier transformer unit is taken as the front side, the two sides adjacent to the front side of the rectifier transformer unit are the side sides of the rectifier transformer unit; The AC line on the low-voltage side of the rectifier transformer unit is directly connected to the upper side of the rectifier transformer unit at the same height as the back of the rectifier cabinet unit; The secondary busbar unit is connected to the lower part of the back of the rectifier transformer unit and the lower part of the side of the rectifier cabinet unit; The secondary busbar unit is connected to the contact elements of the electrode unit so that the length of the connecting copper tube is minimized.

3. The DC ore-generating furnace rectification power supply system according to claim 1, characterized in that: The rectifier transformer unit includes a rectifier transformer unit body; High-voltage porcelain bottle: installed on the upper part of the rectifier transformer unit near the front, used to connect to the high-voltage incoming power supply; Junction box: It is located on the upper front of the rectifier transformer unit and is used for transformer signal convergence. High-voltage side neutral point: located on the upper part of the rectifier transformer unit near the front, used for connecting the neutral point grounding device; Oil tank: It is located on the upper part of the rectifier transformer unit near the back and is used to hold transformer cooling oil; Low-voltage side AC terminal block: Located on the upper side of the rectifier transformer unit body, it is used to connect to the secondary busbar unit. A copper plate is used here to connect the low-voltage side AC terminal block to the secondary busbar unit. The rectifier-side water-cooling hard copper tube of the secondary busbar unit is welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block with bolts. Low-voltage side neutral point terminal block: Located at the lower back of the rectifier transformer unit body, it is used to connect to the secondary bus unit. A copper plate is used here to connect the low-voltage side neutral point terminal block to the secondary bus unit. The two rectifier-side water-cooled hard copper tubes of the secondary bus unit are welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block with bolts.

4. The DC ore-bearing furnace rectification power supply system according to claim 1, characterized in that: The rectifier cabinet unit includes: Output positive water-cooled copper busbar: Arranged at equal intervals inside the rectifier cabinet unit and extending outside the cabinet, it is used to connect to the secondary busbar unit. Here, a copper plate is used to connect the output positive water-cooled copper busbar to the secondary busbar unit. The two rectifier-side water-cooled hard copper tubes of the secondary busbar unit are welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block with bolts. Output negative water-cooling copper busbar: Arranged at equal intervals inside the rectifier cabinet unit and extending outside the cabinet, it is used to connect to the secondary busbar unit. Here, a copper plate is used to connect the output negative water-cooling copper busbar to the secondary busbar unit. The two rectifier-side water-cooling hard copper tubes of the secondary busbar unit are welded to the copper plate. Holes are punched in the copper plate and fixed to the low-voltage side AC terminal block with bolts. The low-voltage side neutral point terminal block, output positive water-cooling copper busbar, and output negative water-cooling copper busbar should be kept at the same height; Input AC water-cooling copper busbars: They are arranged vertically in pairs at equal intervals inside the rectifier cabinet unit and are used to connect to the secondary busbar unit inside the cabinet. They are fixed to the hard busbars of the flexible copper busbars with bolts.

5. The DC ore-generating furnace rectification power supply system according to claim 1, characterized in that: The secondary busbar unit includes a rectifier-side water-cooled hard copper tube, a water-cooled flexible copper tube, an electrode-side water-cooled hard copper tube, and a contact element; One end of the water-cooled hard copper tube on the rectifier side is connected to one end of the water-cooled flexible copper tube; the other end of the water-cooled flexible copper tube is connected to the water-cooled hard copper tube on the electrode side; The contact elements are configured in 8 pieces for each electrode, and each piece is welded to two water-cooled hard copper tubes on the electrode side, used for one inlet and one outlet of the water channel; The contact elements on the positive electrode are numbered 1 and 9, those closest to the rectifier system; Contact elements 1-8 are numbered in a clockwise direction starting from number 1; Contact elements 9-16 are numbered counterclockwise starting from number 9; The numbering of the contact elements on the negative electrode is mirror-symmetrical to the numbering of the contact elements on the positive electrode; The low-voltage side neutral point terminal block of the rectifier transformer unit, the output positive water-cooled copper busbar of the rectifier cabinet unit, and the output negative water-cooled copper busbar of the rectifier cabinet unit are respectively connected to the contact elements of the electrode unit phases through the secondary bus unit.

6. The DC ore-generating furnace rectification power supply system according to claim 1, characterized in that: Name the low-voltage side AC terminal blocks of the rectifier transformer unit and the input AC water-cooling copper busbars of the rectifier cabinet unit with the same letter numbers according to the coil group: a1 to a8, b1 to b8, and c1 to c8. Similarly, name the low-voltage side neutral point terminal blocks of the rectifier transformer unit O1 to O8, name the output positive water-cooling copper busbars of the rectifier cabinet unit P1, P3, P5, and P7, and name the output negative water-cooling copper busbars of the rectifier cabinet unit N2, N4, N6, and N8. The terminal blocks connecting the rectifier transformer unit and the rectifier cabinet unit with positive output polarity are a5, c3, a7, c1, b5, b3, b7, b1, c5, a3, c7, and a1 from the front to the side of the rectifier transformer unit. The terminal blocks connecting the rectifier transformer unit and the rectifier cabinet unit with negative output polarity are c8, a2, c6, a4, b8, b2, b6, b4, a8, c2, a6, and c4 from the front to the side of the rectifier transformer unit. The terminal block numbers of the output positive water-cooling copper busbar of the rectifier cabinet unit are P5, P3, P7, and P1 from the outside to the inside; The terminal block numbers of the output negative water-cooling copper busbar of the rectifier cabinet unit are N8, N2, N6, and N4 from the outside to the inside; Pipeline connections are made based on the principle of minimum total resistance deviation adopted by the secondary busbar unit; There are 32 contact elements in total. The positive electrodes are named J+1 to J+16, and the negative electrodes are named J-1 to J-16. When the secondary busbar unit is arranged, the connection is as follows: The lower copper tube of P5 is connected to the J+1 contact element, the upper copper tube of P5 is connected to the J+2 contact element, the lower copper tube of P3 is connected to the J+3 contact element, the upper copper tube of P3 is connected to the J+4 contact element, the lower copper tube of P7 is connected to the J+5 contact element, the upper copper tube of P7 is connected to the J+6 contact element, the lower copper tube of P1 is connected to the J+7 contact element, and the upper copper tube of P1 is connected to the J+8 contact element; the lower copper tube of O8 is connected to the J+9 contact element, the upper copper tube of O8 is connected to the J+10 contact element, the lower copper tube of O4 is connected to the J+11 contact element, the upper copper tube of O4 is connected to the J+12 contact element, the lower copper tube of O6 is connected to the J+13 contact element, the upper copper tube of O6 is connected to the J+14 contact element, the lower copper tube of O2 is connected to the J+15 contact element, and the upper copper tube of O2 is connected to the J+16 contact element; The lower copper tube of O1 is connected to the J-9 contact element, the upper copper tube of O1 is connected to the J-10 contact element, the lower copper tube of O5 is connected to the J-11 contact element, the upper copper tube of O5 is connected to the J-12 contact element, the lower copper tube of O3 is connected to the J-13 contact element, the upper copper tube of O3 is connected to the J-14 contact element, the lower copper tube of O7 is connected to the J-15 contact element, and the upper copper tube of O7 is connected to the J-16 contact element; the lower copper tube of N8 is connected to the J-1 contact element, the upper copper tube of N8 is connected to the J-2 contact element, the lower copper tube of N2 is connected to the J-3 contact element, the upper copper tube of N2 is connected to the J-4 contact element, the lower copper tube of N6 is connected to the J-5 contact element, the upper copper tube of N6 is connected to the J-6 contact element, the lower copper tube of N4 is connected to the J-7 contact element, and the upper copper tube of N4 is connected to the J-8 contact element.

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