Pole coil for evaporative cooling of vertical hydro-generator rotor

Abstract

The invention belongs to the field of hydro-generators, in particular to a pole coil for evaporative cooling of a vertical hydro-generator rotor, which comprises N hollow copper wires, an interlayer insulating medium, a liquid inlet side electric connector, a liquid inlet connector, a gas outlet connector and a gas outlet side electric connector, the magnetic pole coil is sleeved outside the rotor pole body of the vertical hydro-generator, the cooling medium enters the inner hole of the hollow copper wire of the magnetic pole coil through the liquid inlet connector, the magnetic pole coil emits heat when the magnetic pole coil is electrified, the cooling medium absorbs heat of the magnetic pole coil to heat the cooling medium, and when the evaporation temperature of the medium is reached, the cooling medium is cooled. Part of the cooling medium is converted into a gas state from a liquid state to form a two-phase flow, the dryness of the two-phase flow is gradually reduced along with forward flowing of the two-phase flow, the two-phase flow reaches the minimum and steady state at the gas outlet connector, and the vertical hydro-generator rotor coil is subjected to evaporative cooling; the problem that in the prior art, a vertical hydro-generator rotor coil is poor in cooling effect is solved.

Description

Technical Field

[0001] The present application belongs to the field of hydro-generators, and in particular to a magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor. Background Art

[0002] Currently, large hydro-turbine generators (giant units) over 600MW have three cooling methods: all-air cooling, evaporative cooling, and water-cooling. All-air cooling is an external cooling technology, while evaporative cooling and water-cooling are both direct cooling technologies. Due to its simple structure, reliable operation, and easy maintenance, all-air cooling effectively reduces secondary operating costs of power plants and is therefore very popular among users. While it can meet the requirements of smaller generators, it cannot meet the requirements of hydro-turbine generators with higher power densities, leaving direct cooling as the only option. Among direct cooling technologies, evaporative cooling is more popular due to its higher safety and reliability than water-cooling. However, in terms of cooling capacity, evaporative cooling utilizes phase change to absorb heat, while water-cooling absorbs heat based on specific heat, making it weaker than evaporative cooling. In terms of accident control, the evaporative cooling medium is insulating, so leaks will not escalate accidents. However, in water-cooling, leaks will become conductive, further escalating the accident, making it weaker than evaporative cooling. Therefore, evaporative cooling is currently the preferred direct cooling technology. At present, the hydro-turbine generators that use evaporative cooling mainly use evaporative cooling for the stator coils. Since there is no corresponding evaporative cooling method for the rotor coils, they can only use full air cooling. In addition, the evaporative cooling method faces the problem of temperatures exceeding the allowable range of Class B insulation. The current solution to this problem is to use Class H insulation materials, but this solution has not yet been recognized by the industry and owners. Summary of the Invention

[0003] In order to solve the problem of poor cooling effect of rotor coil of vertical hydro-generator in the prior art, a magnetic pole coil for evaporative cooling of rotor of vertical hydro-generator is proposed. A magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor, comprising: N hollow copper wires, an interlayer insulating medium, a liquid inlet side electrical connector, a liquid inlet connector, a gas outlet connector, and a gas outlet side electrical connector; N is a positive integer; N hollow copper wires are arranged in a straight line. After the two ends of the arranged N hollow copper wires are left with a set distance, they are wound M times in a set direction to form an M-turn coil. An interlayer insulating medium is filled between two adjacent turns of the coil. The liquid inlet side electrical connector is connected to one end of each hollow copper wire, and the gas outlet side electrical connector is connected to the other end of each hollow copper wire. The liquid inlet side electrical connector and the gas outlet side electrical connector are also connected to an external power supply. The liquid inlet side electrical connector, the gas outlet side electrical connector, the N hollow copper wires, and the external power supply form an energized circuit, so that current flows through the M turns of the coil. The liquid inlet joint is connected to one end of each hollow copper wire, and is used to input the cooling medium into the inner hole of each hollow copper wire of the M-turn coil; the M-turn coil is sleeved on the outside of the rotor pole body of the hydro-generator. After the M-turn coil is energized, the coil temperature increases, the cooling medium temperature increases, and the cooling medium evaporates to form a two-phase flow; the gas outlet joint is connected to the other end of each hollow copper wire, and is used to allow the two-phase flow formed by the cooling medium inside the hollow copper wire to flow out.

[0004] Beneficial effects: The present application discloses a pole coil for evaporative cooling of a vertical hydro-turbine generator rotor, which is sleeved on the outside of the pole body of the vertical hydro-turbine generator rotor. The cooling medium enters the inner hole of the hollow copper wire of the pole coil through the liquid inlet joint under pressure. When the pole coil is energized, the pole coil generates heat, and the cooling medium absorbs the heat of the pole coil to heat the cooling medium. When the evaporation temperature of the medium is reached, part of the cooling medium is converted from liquid to gas, forming a two-phase flow. As the two-phase flow flows forward, the dryness of the two-phase flow gradually decreases, reaching a minimum at the gas outlet joint, and achieving a steady-state two-phase flow. The present application discloses a pole coil for evaporative cooling of a vertical hydro-turbine generator rotor, which can perform evaporative cooling on the vertical hydro-turbine generator rotor after energization, so that the hydro-turbine generator rotor also uses evaporative cooling technology, forming a matching combination with the stator evaporative cooling technology, meeting the design requirements of the hydro-turbine generator, and improving the safety and reliability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 This is a front view of a magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor according to a specific embodiment of the present application; Figure 2 This is a front view AA section view of a magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor according to a specific embodiment of the present application; Figure 3 A top view of a magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor according to a specific embodiment of the present application; Figure 4 A top view, BB section view, and CC section view of a magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor according to a specific embodiment of the present application; In the figure, 1 is a hollow copper wire, 2 is an interlayer insulating medium, 3 is a liquid inlet side electrical connector, 4 is a liquid inlet connector, 5 is a gas outlet connector, and 6 is a gas outlet side electrical connector. DETAILED DESCRIPTION

[0006] Specific implementation method 1: The following is combined with the attached embodiment of the present invention Figure 1 To the attached Figure 4 , illustrate this embodiment, and clearly and completely describe the technical solutions in the embodiments of the present invention: A magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor, comprising: N hollow copper wires 1, an interlayer insulating medium 2, a liquid inlet side electrical connector 3, a liquid inlet connector 4, a gas outlet connector 5, and a gas outlet side electrical connector 6; N is a positive integer; N hollow copper wires 1 are arranged in a straight line, with a set distance between both ends of the arranged N hollow copper wires 1 and then wound M times in a set direction to form an M-turn coil, with an interlayer insulating medium 2 filled between two adjacent turns of the coil; The liquid inlet-side electrical connector 3 is connected to one end of each hollow copper wire 1, and the gas outlet-side electrical connector 6 is connected to the other end of each hollow copper wire 1. The liquid inlet-side electrical connector 3 and the gas outlet-side electrical connector 6 are also connected to an external power supply. The liquid inlet-side electrical connector 3, the gas outlet-side electrical connector 6, the N hollow copper wires 1, and the external power supply form an energized circuit, allowing current to flow through the M turns of the coil. The liquid inlet connector 4 is connected to one end of each hollow copper wire 1, and is used to input the cooling medium into the inner hole of each hollow copper wire 1 of the M-turn coil; the M-turn coil is sleeved on the outside of the rotor pole body of the hydro-generator. After the M-turn coil is energized, the coil temperature increases, the cooling medium temperature increases, and the cooling medium evaporates to form a two-phase flow; the gas outlet connector 5 is connected to the other end of each hollow copper wire 1, and is used to allow the two-phase flow formed by the cooling medium inside the hollow copper wire 1 to flow out.

[0007] Furthermore, the section from one end of the N hollow copper wires 1 to the starting end of the first coil is set as the input section, and the section from the end of the Mth coil to the other end of the N hollow copper wires 1 is set as the output section, and the input section is parallel to the output section.

[0008] Furthermore, the hollow copper wire 1 is a rectangular hollow copper wire 1 , and the inner hole of the hollow copper wire 1 is rectangular in shape.

[0009] Furthermore, the inner hole height of the hollow copper wire 1 is in the range of 1 mm to 8 mm. Furthermore, the cooling medium is a fluoride liquid. The fluoride liquid has a boiling point temperature range of 45°C to 62°C, a latent heat of vaporization ≥110KJ / kg, a power frequency breakdown voltage ≥20kV, a liquid viscosity ≤0.7mPas, and meets the requirements of ozone damage potential, global warming potential, and compatibility with polytetrafluoroethylene tubes, copper, stainless steel, and rubber.

[0010] Furthermore, the interlayer insulating medium 2 is an F-class epoxy glass cloth board and an F-class insulating adhesive. The F-class insulating adhesive facilitates fixing and shaping the magnetic pole coil.

[0011] Embodiment: Two strands of hollow copper wire 1 are wound in a clockwise direction on a magnetic pole body mold, and an insulating medium 2 is placed between each layer. The winding reaches the designed number of turns according to technical requirements, and the two ends of the wound strands are arranged. Insulating medium powder and insulating glue are filled between the strands to improve the integrity of the magnetic pole coil. The magnetic pole coil is removed from the magnetic pole body mold, and a mold composed of a magnetic pole drag plate is placed to shape and solidify the magnetic pole coil.

[0012] At both ends of the pole coil, weld the liquid inlet electrical connector 3, liquid inlet connector 4, gas outlet connector 5 and gas outlet electrical connector 6 respectively, and put the pole coil on the hydro-generator magnetic pole body to form the hydro-generator magnetic pole. Figure 1 and Figure 3 The diagram shows an open-end coil; the closed-end coil has the same setup. The cooling medium enters the hollow copper wire 1 through the liquid inlet connector 4 of the pole coil and flows out through the air outlet connector 5 under pressure. When the pole coil is energized, the hollow copper wire 1 heats up, which in turn heats the cooling medium. When the cooling medium reaches its evaporation temperature, it absorbs the heat from the pole coil and transforms from liquid to gas, forming a two-phase flow within the hollow copper wire 1. As the medium flows forward, the dryness of the two-phase flow gradually decreases, reaching a minimum at the outlet of the rotor coil, i.e., the air outlet connector 5. Thereafter, it remains constant, achieving a steady-state two-phase flow. Adjusting the pressure differential across the pole coil ensures a two-phase flow at the air outlet connector, ensuring effective cooling of the pole coil.

[0013] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be employed in conjunction with other described embodiments.

Claims

1. A magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor, characterized in that: include: N hollow copper wires, interlayer insulating medium, liquid inlet side electrical connector, liquid inlet connector, gas outlet connector and gas outlet side electrical connector; N is a positive integer; N hollow copper wires are arranged in a straight line. After the two ends of the arranged N hollow copper wires are left with a set distance, they are wound M times in a set direction to form an M-turn coil. An interlayer insulating medium is filled between two adjacent turns of the coil. The liquid inlet side electrical connector is connected to one end of each hollow copper wire, and the gas outlet side electrical connector is connected to the other end of each hollow copper wire. The liquid inlet side electrical connector and the gas outlet side electrical connector are also connected to an external power supply. The liquid inlet side electrical connector, the gas outlet side electrical connector, the N hollow copper wires, and the external power supply form an energized circuit, so that current flows through the M turns of the coil. The liquid inlet joint is connected to one end of each hollow copper wire, and is used to input the cooling medium into the inner hole of each hollow copper wire of the M-turn coil; the M-turn coil is sleeved on the outside of the rotor pole body of the hydro-generator. After the M-turn coil is energized, the coil temperature increases, the cooling medium temperature increases, and the cooling medium evaporates to form a two-phase flow; the gas outlet joint is connected to the other end of each hollow copper wire, and is used to allow the two-phase flow formed by the cooling medium inside the hollow copper wire to flow out.

2. The magnetic pole coil for evaporative cooling of a vertical hydro-generator rotor according to claim 1, characterized in that: The section from one end of the N hollow copper wires to the starting end of the first coil is set as the input section, and the section from the end of the Mth coil to the other end of the N hollow copper wires is set as the output section. The input section is parallel to the output section.

3. The pole coil for evaporative cooling of a vertical hydro-generator rotor according to claim 1, characterized in that: The hollow copper wire is a rectangular hollow copper wire, and the shape of the inner hole of the hollow copper wire is a rectangle.

4. The pole coil for evaporative cooling of a vertical hydro-generator rotor according to claim 3, characterized in that: The inner hole height of the hollow copper wire ranges from 1mm to 8mm.

5. The pole coil for evaporative cooling of a vertical hydro-generator rotor according to claim 1, characterized in that: The cooling medium is fluoride liquid.

6. The pole coil for evaporative cooling of a vertical hydro-generator rotor according to claim 1, characterized in that: The interlayer insulation medium is F-class epoxy glass cloth board and F-class insulating glue.

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