Pump body heating device for main water feeding pump of nuclear power station

Abstract

The utility model discloses a nuclear power station main feed pump body heating device which comprises at least one heating body, the heating body comprises a metal shell and a heating main body, at least one side face of the metal shell is a plane, the heating main body is installed in the metal shell, and the heating main body comprises an insulating rod, a metal outgoing line and a heating line. The heating wire is spirally wound on the periphery of the insulating rod, the metal lead-out wire is embedded in the insulating rod, a part of the metal lead-out wire is connected with the heating wire, and the other part of the metal lead-out wire protrudes out of the insulating rod. The nuclear power station main feed pump body heating device mainly solves the implementation problem of on-site complex-shape equipment pump body heating, compared with an existing direct disassembling method, the nuclear power station main feed pump core package disassembling success rate can be effectively increased, high-value equipment is prevented from being damaged in the disassembling process, and the nuclear power station main feed pump core package disassembling efficiency is improved. And the maintenance and spare part replacement cost can be greatly reduced. When the pump body heating device of the main water feeding pump of the nuclear power station is installed and heated, accessories outside the pump body cannot be affected.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear power, in particular to a pump body heating device for a main feed water pump of a nuclear power station. Background Art

[0002] The electric main feedwater pump is one of the important conventional pumps in nuclear power plants and is an important non-nuclear grade pump. The main function of the main feedwater pump in a pressurized water reactor nuclear power plant is to pump water and boost the pressure through the main feedwater pump, and then send it to the steam generator through the high-pressure heater; in addition, the main feedwater system is required to be able to respond to speed changes to ensure that different feedwater flows are provided to the steam generator within the entire thermal load range of the reactor. If the main feedwater pump fails, the nuclear power unit will trip or even shut down. The main feedwater pump plays a vital role in the stable and efficient operation of nuclear power plants.

[0003] like Figure 1 As shown, when the main feed water pump of the nuclear power plant is installed, the pump cover 200 is embedded in the pump body 100 and fastened with bolts. The installation gap between the pump cover 200 and the pump body 100 is extremely small, and the pump cover 200 is not easy to be pulled out from the pump body 100 when the pump body 100 is disassembled for inspection. The pump body 100 and the pump cover 200 are both made of alloy material, and the main body can be heated by heating to create a gap between the pump body 100 and the pump cover 200. However, the main feed water pump of the nuclear power plant has a complex appearance and structure, and a large number of pipes and accessories are installed on the outside. The use of fire heating and other methods cannot meet the on-site needs well. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a pump body heating device for a main feed water pump of a nuclear power plant.

[0005] The technical solution adopted by the utility model to solve the technical problem is: construct a nuclear power plant main feed water pump body heating device, including at least one heating element, the heating element includes a metal shell and a heating body, at least one side of the metal shell is a plane, the heating body is installed in the metal shell, and the heating body includes an insulating rod, a metal lead wire, and a heating wire;

[0006] The heating wire is spirally wound around the outer circumference of the insulating rod, the metal lead wire is buried in the insulating rod, a part of the metal lead wire is connected to the heating wire, and another part of the metal lead wire protrudes from the insulating rod.

[0007] In some embodiments, an insulating thermally conductive material is filled between the inner wall surface of the metal shell and the outer wall surface of the insulating rod.

[0008] In some embodiments, the insulating rod is in the shape of a round column or a square column.

[0009] In some embodiments, the cross-section of the metal shell is square.

[0010] In some embodiments, the heating wire is a nickel-chromium heating wire.

[0011] In some embodiments, the heating wire is a nickel-iron heating wire.

[0012] In some embodiments, the metal shell is a stainless steel shell.

[0013] In some embodiments, the metal shell is a copper shell.

[0014] In some embodiments, the nuclear power plant main feed water pump body heating device further includes at least one plug, and at least one of the plugs is connected to the metal lead wire.

[0015] In some embodiments, the number of the heating elements is at least two;

[0016] The pump body heating device of the main feed water pump of the nuclear power plant further comprises a connecting piece, and the connecting piece is sleeved on the outer periphery of the connection between at least two of the heating elements.

[0017] The implementation of the utility model has the following beneficial effects: the pump body heating device of the main feed water pump of a nuclear power plant mainly solves the implementation problem of heating the pump body of equipment with complex shapes on site. Compared with the existing direct disassembly method, it can effectively improve the success rate of disassembly of the core package of the main feed water pump of a nuclear power plant, prevent high-value equipment from being damaged during the disassembly process, and greatly reduce the cost of maintenance and spare parts replacement. The use of the pump body heating device of the main feed water pump of a nuclear power plant does not affect the extraction of the pump cover. In addition, the external pipes of the pump body are crisscrossed, and when the pump body heating device of the main feed water pump of a nuclear power plant is installed and heated, it will not affect the accessories outside the pump body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the utility model, the utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the utility model, and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0019] Figure 1 It is a structural schematic diagram of a main feed water pump for a nuclear power plant in the related art;

[0020] Figure 2 This is one of the application schematic diagrams of the pump body heating device of the main feed water pump of a nuclear power plant in some embodiments of the utility model;

[0021] Figure 3This is the second application schematic diagram of the pump body heating device of the main feed water pump of a nuclear power plant in some embodiments of the utility model;

[0022] Figure 4 It is a schematic diagram of the structure of the heating element in some embodiments of the utility model;

[0023] Figure 5 is a cross-sectional view of a heating element in some embodiments of the utility model;

[0024] Figure 6 It is a schematic diagram of the structure of the heating body in some embodiments of the utility model;

[0025] Figure 7 It is a schematic structural diagram of a pump body heating device for a main feed water pump of a nuclear power plant in some embodiments of the utility model;

[0026] Figure 8 It is a schematic structural diagram of a pump body heating device for a main feed water pump of a nuclear power plant in other embodiments of the utility model. DETAILED DESCRIPTION

[0027] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0028] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0029] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the present invention.

[0030] See also Figures 2 to 7 The utility model shows a pump body heating device for a main feed water pump of a nuclear power plant, which can be arranged around the outer periphery of a pump body 100 of the main feed water pump of the nuclear power plant to heat the pump body 100, so that the pump body 100 heats up and expands. There is a temperature difference between the pump body 100 and the pump cover 200, so that a gap is generated between the pump body 100 and the pump cover 200, making it convenient to remove the pump cover 200 from the pump body 100.

[0031] like Figures 4 to 6 As shown, the nuclear power plant main feed water pump body heating device includes at least one heating element 10, and the heating element 10 includes a metal shell 11 and a heating body 12. At least one side of the metal shell 11 is a plane. The heating body 12 is installed in the metal shell 11, and the heating body 12 includes an insulating rod 121, a metal lead wire 122, and a heating wire 123.

[0032] The heating wire 123 is spirally wound around the outer circumference of the insulating rod 121, the metal lead wire 122 is buried in the insulating rod 121, and part of the metal lead wire 122 is connected to the heating wire 123, and the other part of the metal lead wire 122 protrudes from the insulating rod 121. For example, one end of the metal lead wire 122 is connected to one end of the heating wire 123, and the other end of the metal lead wire 122 protrudes from the insulating rod 121 / metal shell 11 to serve as positive and negative terminal terminals connected to the plug 20.

[0033] In some embodiments, the cross-sectional shape of the metal shell 11 is square, which can better fit the surface of the pump body 100, has higher heat conduction efficiency, and faster heating speed.

[0034] In addition, the cross-sectional shape of the metal shell 11 is a square, which increases the creepage distance between the heating wire 123 and the metal shell 11, and improves the electrical, mechanical and life performance. Preferably, the cross-sectional shape of the metal shell 11 is a rectangle, that is, the metal shell 11 can have multiple planes.

[0035] In some embodiments, the metal shell 11 is a stainless steel shell. Alternatively, the metal shell 11 is a copper shell. Using the metal shell 11 as armor can solve the problems of the shell material in the related art being non-metallic material, being easy to age, break, and unable to withstand high temperature.

[0036] In some embodiments, the insulating rod 121 can be a round column or a square column under normal conditions. Preferably, the insulating rod 121 can be a round column. The insulating rod 121 can be a silicone rod or a rubber rod. Of course, the insulating rod 121 can also be made of other elastic and soft insulating materials.

[0037] In some embodiments, the heating wire 123 is a nickel-chromium heating wire 123 . Alternatively, the heating wire 123 is a nickel-iron heating wire 123 .

[0038] Understandably, the heating wire 123 can be a nickel-chromium heating wire, a nickel-iron heating wire or other alloy heating wire. The heating wire 123 is used as a heat source. It is wound into a spiral shape, which can greatly increase the power of the heating element 10 and achieve the purpose of quickly heating the pump body 100. The heating wire 123 is installed in the metal shell 11, so that the metal shell 11 forms a metal armor for the heating wire 123.

[0039] The heating wire 123 and the metal lead wire 122 (used as a power connection wire) can be connected by welding. The metal lead wire 122 can be made of pure nickel wire with good electrical conductivity and heat resistance. This combination of materials and processes overcomes the defect that the connection position produced by the traditional riveting connection method is easy to break. The length of the soft pure nickel wire forms the cold end of the heating element 10, ensuring that the cold end of the heating element 10 can be bent at a large angle, reducing the difficulty of forming the heating element 10.

[0040] In some embodiments, the space between the inner wall of the metal shell 11 and the outer wall of the insulating rod 121 is filled with an insulating thermally conductive material 13. The insulating thermally conductive material 13 may be a mineral insulating material, which may be magnesium oxide or other high temperature resistant insulating materials.

[0041] In some embodiments, the heating element 10 is prepared as follows: the spirally wound heating wire 123 and the metal lead wire 122 are welded to form a heating body 12, the heating body 12 is completely inserted into the metal shell 11, and the gap between the metal shell 11 and the heating body 12 is filled with insulating thermal conductive material 13. Then, a compression device can be used to compress the metal shell 11 into a rectangle, ensuring good thermal conductivity and electrical performance that meets the requirements. At the same time, the position of the heating body 12 is also fixed to ensure the stability of the electrical performance.

[0042] In some embodiments, the nuclear power plant main feed water pump body heating device further includes at least one plug 20 , and the at least one plug 20 is connected to the metal lead wire 122 .

[0043] In some embodiments, the number of the heating elements 10 is at least two; the main feed water pump body heating device of the nuclear power plant further includes a connector 30, which is sleeved on the periphery of the connection between at least two heating elements 10. The connector 30 may be made of an insulating material, which may be a silicone member or a rubber member, or made of other materials. In some embodiments, a female connector may be provided at one end of a heating element 10, and a male connector may be provided at one end of a heating element 10, and two adjacent heating elements 10 may be connected together by connecting the female connector to the male connector.

[0044] In some embodiments, the pump body heating device of the main feedwater pump of the nuclear power plant can have two types of single-end outlet and two-end outlet. The following describes the implementation methods of the two wiring methods:

[0045] like Figure 7 As shown, it is a single-end outlet method: the power line is welded on the top of the heating element 10, and a plug 20 is installed at the end to facilitate the use of an electrical box to draw power. The non-heating position of the heating element 10 is welded and fixed to the heating position (brazing / argon arc welding or resistance welding, etc.) and the outside is fixed with a connector 30. The tail can be fixed with a connector 30 with a closed end.

[0046] like Figure 8 As shown, the two-end outlet method is: the non-heating position at both ends of the heating element 10 is welded and fixed to the heating position (brazing / argon arc welding or resistance welding, etc.) and the outside is fixed with a connector 30. The power line is welded on the top of the heating element 10, and a plug 20 is installed at the end to facilitate the use of an electrical box to draw power.

[0047] In some embodiments, the main feed water pump body heating device of the nuclear power plant is applied as follows:

[0048] The pump body heating device of the main feed water pump of the nuclear power plant can be evenly wound around the outside of the pump body 100, fixed with a metal buckle or a band, and the plug 20 is reserved on the outside of the pump body 100. The outside of the pump body heating device of the main feed water pump of the nuclear power plant (mainly the heating element 10) can be covered with a high temperature resistant insulation material, and the insulation material is fixed with a metal buckle or a metal band. The plug 20 can be connected to the power control box, and the temperature control box can adopt multi-point temperature control. The temperature control temperature detection point position (temperature sensors can be set for temperature detection) is the upper, middle and lower points of the pump body. Ensure that the entire pump body 100 is heated evenly to prevent it from thermal distortion or local thermal expansion, which causes the pump cover 200, shaft and rotor of the pump body 100 to be further locked inside the pump body 100. Of course, the temperature control method can select the existing mature temperature control method, which is not specifically limited here.

[0049] It can be understood that the pump body heating device of the main feed water pump of the nuclear power plant mainly solves the implementation problem of heating the pump body 100 of the complex-shaped equipment on site. Compared with the existing direct disassembly method, it can effectively improve the success rate of disassembly of the core package of the main feed water pump of the nuclear power plant, prevent high-value equipment from being damaged during the disassembly process, and greatly reduce the maintenance and spare parts replacement costs. And the use of the pump body heating device of the main feed water pump of the nuclear power plant does not affect the extraction of the pump cover 200. In addition, the external pipelines of the pump body 100 are crisscrossed, and when the pump body heating device of the main feed water pump of the nuclear power plant is installed and heated, it will not affect the accessories outside the pump body 100.

[0050] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should fall within the scope of the claims of the utility model.

Claims

1. A pump body heating device for a main feed water pump of a nuclear power plant, characterized in that: The device comprises at least one heating element (10), wherein the heating element (10) comprises a metal shell (11) and a heating body (12), at least one side surface of the metal shell (11) is a plane, the heating body (12) is installed in the metal shell (11), and the heating body (12) comprises an insulating rod (121), a metal lead wire (122), and a heating wire (123); The heating wire (123) is spirally wound around the outer circumference of the insulating rod (121), the metal lead wire (122) is buried in the insulating rod (121), a portion of the metal lead wire (122) is connected to the heating wire (123), and another portion of the metal lead wire (122) protrudes from the insulating rod (121).

2. The nuclear power plant main feed water pump body heating device according to claim 1, characterized in that: An insulating heat-conducting material (13) is filled between the inner wall surface of the metal shell (11) and the outer wall surface of the insulating rod (121).

3. The nuclear power plant main feed water pump body heating device according to claim 1, characterized in that: The insulating rod (121) is in the shape of a round column or a square column.

4. The nuclear power plant main feed water pump body heating device according to claim 1, characterized in that: The cross section of the metal shell (11) is square.

5. The nuclear power plant main feed water pump body heating device according to claim 1, characterized in that: The heating wire (123) is a nickel-chromium heating wire (123).

6. The nuclear power plant main feed water pump body heating device according to claim 1, characterized in that: The heating wire (123) is a nickel-iron heating wire (123).

7. The nuclear power plant main feed water pump body heating device according to claim 1, characterized in that: The metal shell (11) is a stainless steel shell.

8. The nuclear power plant main feed water pump body heating device according to claim 1, characterized in that: The metal shell (11) is a copper shell.

9. The nuclear power plant main feed water pump body heating device according to any one of claims 1 to 8, characterized in that: The nuclear power plant main feed water pump body heating device further comprises at least one plug (20), and at least one of the plugs (20) is connected to the metal lead wire (122).

10. The nuclear power plant main feed water pump body heating device according to any one of claims 1 to 8, characterized in that: The number of the heating elements (10) is at least two; The nuclear power plant main feed water pump body heating device further comprises a connecting piece (30), wherein the connecting piece (30) is sleeved on the outer periphery of the connection between at least two of the heating elements (10).

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