CN116066654A - Pipeline system for eliminating nuclear power pipeline thermal fatigue - Google Patents
Pipeline system for eliminating nuclear power pipeline thermal fatigue Download PDFInfo
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- CN116066654A CN116066654A CN202310138571.0A CN202310138571A CN116066654A CN 116066654 A CN116066654 A CN 116066654A CN 202310138571 A CN202310138571 A CN 202310138571A CN 116066654 A CN116066654 A CN 116066654A
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
- F15D1/00—Influencing flow of fluids
- F15D1/002—Influencing flow of fluids by influencing the boundary layer
- F15D1/0065—Influencing flow of fluids by influencing the boundary layer using active means, e.g. supplying external energy or injecting fluid
- F15D1/008—Influencing flow of fluids by influencing the boundary layer using active means, e.g. supplying external energy or injecting fluid comprising fluid injection or suction means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
- F15D1/00—Influencing flow of fluids
- F15D1/02—Influencing flow of fluids in pipes or conduits
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L57/00—Protection of pipes or objects of similar shape against external or internal damage or wear
- F16L57/04—Protection of pipes or objects of similar shape against external or internal damage or wear against fire or other external sources of extreme heat
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L59/00—Thermal insulation in general
- F16L59/02—Shape or form of insulating materials, with or without coverings integral with the insulating materials
- F16L59/028—Composition or method of fixing a thermally insulating material
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17D—PIPE-LINE SYSTEMS; PIPE-LINES
- F17D5/00—Protection or supervision of installations
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Monitoring And Testing Of Nuclear Reactors (AREA)
Abstract
The invention discloses a pipeline system for eliminating thermal fatigue of a nuclear power pipeline, which is used for eliminating thermal fatigue caused by thermal layering effect of the pipeline of a nuclear power plant, the pipeline of the nuclear power plant comprises a first pipeline and at least one second pipeline which is connected and communicated with the first pipeline, the second pipeline is provided with a thermal layering area, and the pipeline system for eliminating thermal fatigue of the nuclear power pipeline comprises: the heat pipe device is arranged on the periphery of the part of the second pipeline, which is positioned in the thermal layering region; and the temperature measuring device is arranged on the periphery of the part of the second pipeline, which is positioned in the thermal layering region, and is used for detecting the temperature of the thermal layering region. The pipeline system for eliminating the nuclear power pipeline thermal fatigue is used for reducing the occurrence of thermal stratification, thermal circulation and thermal shock of the pipeline of the nuclear power plant, and can reduce the occurrence probability of pipeline fatigue, thereby improving the availability of the nuclear power unit, reducing the release risk of radioactive substances and improving the operation safety level of the nuclear power unit.
Description
Technical Field
The invention relates to the technical field of nuclear power, in particular to a pipeline system for eliminating thermal fatigue of a nuclear power pipeline.
Background
Abbreviations and key term definitions:
thermal delamination (Thermal stratification): temperature gradient distribution in a pipe or vessel due to fluid density differences. The broad concept of thermal stratification also includes thermal cycling and thermal shock phenomena.
Thermal Cycling: a phenomenon of temperature fluctuation somewhere on the inner wall surface of the pipe or vessel due to a change in the stratified water level, a change in the fluid temperature, or turbulent permeation.
Thermal vibration (Thermal vibration), a high frequency fluctuation of the cycling temperature over time due to interfacial waves of the layered interface.
During operation of a nuclear power plant, there are many complex thermodynamic phenomena, particularly on stagnant pipes connected to the reactor coolant system, which are connected to the reactor coolant system pipes at one end and subject to high-velocity fluid disturbances, and which are in a stagnant state for a long period of time due to the closed (usually valved) fluid. Complex thermal hydraulic phenomena such as thermal stratification, thermal circulation and thermal shock can be generated under the comprehensive actions of factors such as turbulent permeation, valve leakage, environmental heat dissipation and the like, and the phenomena can cause thermal stress and thermal fatigue influence on a system pipeline for a long time, and even threatens the safety of a nuclear power plant. Experience feedback shows that when the foreign nuclear power station is overhauled in ten years, cracks and even leakage occur at sensitive parts of the pipeline. Therefore, the thermal hydraulic phenomena should be fully considered in the design and operation and maintenance processes of the nuclear power plant.
In the existing nuclear power plant unit design, two main technical schemes for reducing pipeline thermal fatigue caused by thermal stratification, thermal circulation and thermal shock exist: firstly, setting fatigue monitoring and valve leakage monitoring of a sensitive area pipeline; and secondly, performing volume inspection in the unit overhaul process to verify the integrity of the pressure boundary.
The pipeline defect problem caused by the thermal stratification effect has a certain long-term property and concealment, and the pipeline is well checked by the datum point according to the experience feedback of foreign nuclear power stations, and cracks are locally generated after ten years of operation and maintenance. Aiming at the technical characteristics, the prior art has the following problems:
whether monitoring is set or checking is carried out regularly, sensitive positions need to be precisely positioned, and a large amount of screening, analysis and test work needs to be carried out in the early stage.
The prior art is based on a "post-hoc" solution, in which the problem is found before subsequent repair, alleviation or replacement work is carried out. Challenges are presented to plant availability and safety.
Disclosure of Invention
The invention aims to solve the technical problem of providing a pipeline system for eliminating thermal fatigue of a nuclear power pipeline.
The technical scheme adopted for solving the technical problems is as follows: a pipe system for eliminating thermal fatigue of a nuclear power plant pipe including a first pipe and at least one second pipe connected to and in communication with the first pipe, the second pipe having a thermal stratification region, the pipe system for eliminating thermal fatigue of a nuclear power plant pipe comprising:
the heat pipe device is arranged on the periphery of the part of the second pipeline, which is positioned in the thermal layering region;
and the temperature measuring device is arranged at the periphery of the part of the second pipeline, which is positioned in the thermal layering region, and is used for detecting the temperature of the thermal layering region.
In some embodiments, the hot end of the heat pipe device is in contact with the top of the second pipe and the cold end of the heat pipe device is in contact with the bottom of the second pipe.
In some embodiments, the heat pipe device includes a plurality of heat pipes, each two heat pipes are symmetrically arranged at the periphery of the second pipe to form a heat pipe group, and the plurality of heat pipe groups are arranged along the axial direction of the second pipe.
In some embodiments, the amount of heat required to heat the cold fluid in the thermally stratified region is calculated by the following formula:
Q 1 ＝c·m·ΔT
wherein c is the specific heat of water; Δt: temperature difference of cold and hot fluid, Δt=t Thermal fluid -T Cold fluid The method comprises the steps of carrying out a first treatment on the surface of the m: the water mass of the heated pipe is such that,
ρ cold fluid : cold fluid density; d: the pipe diameter of the layered pipeline; l: the length of the layered pipeline;
the heat absorption capacity of the heat pipe is calculated by the following formula:
Q 2 ＝K·A·ΔT m ·t；
wherein, K: the heat transfer coefficient is determined according to the heat pipe material; a: total heat transfer area; delta T m : the logarithmic average temperature difference,
ΔT max ＝T thermal fluid -T 1 ；ΔT min ＝T Cold fluid -T 1 ；T 1 : the saturation temperature of the fluid in the heat pipe; t: heating time;
the number of heat pipes is calculated from the following formula:
wherein Q is 2 ＝η·Q 1 The eta heat loss coefficient is 0.98; f: heat transfer area of a single heat pipe.
In some embodiments, the heat pipe is circular, square, or oval in cross-section.
In some embodiments, the temperature measuring device comprises a plurality of temperature measuring units, and the plurality of temperature measuring units are arranged on the periphery of the thermal stratification region of the second pipeline along the axial direction and/or the circumferential direction of the second pipeline.
In some embodiments, the plurality of temperature measuring units are symmetrically arranged along the axial direction of the second pipeline on the upper outer surface and the lower outer surface of the thermal stratification region of the second pipeline.
In some embodiments, the temperature measurement unit comprises a thermocouple or a thermal resistor.
In some embodiments, the temperature measuring device is communicatively coupled to a power plant master.
In some embodiments, the tubing for eliminating thermal fatigue of nuclear power plant tubing includes a heat preservation layer disposed about the periphery of the nuclear power plant tubing;
the heat pipe device and the temperature measuring device are both arranged in the heat insulation layer.
In some embodiments, the insulating layer is made of at least one of rock wool, aluminum silicate wool, glass wool, or foam glass.
In some embodiments, the tubing for eliminating thermal fatigue of a nuclear power pipeline includes a thermal insulation layer disposed about a periphery of a midsection of the heat pipe.
In some embodiments, the insulating layer is made of at least one of rock wool, aluminum silicate wool, glass wool, or foam glass.
In some embodiments, the second conduit comprises a first branch connected to the first conduit and a second branch connected to an end of the first branch remote from the first conduit, the second branch having the thermal stratification region;
the heat pipe device and the temperature measuring device are arranged on the periphery of the part of the second branch pipe, which is positioned in the thermal layering region.
The implementation of the invention has the following beneficial effects: the pipeline system for eliminating the nuclear power pipeline thermal fatigue is used for reducing the occurrence of thermal stratification, thermal circulation and thermal shock of the pipeline of the nuclear power plant, and can reduce the occurrence probability of pipeline fatigue, thereby improving the availability of the nuclear power unit, reducing the release risk of radioactive substances and improving the operation safety level of the nuclear power unit.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the following description will be given with reference to the accompanying drawings and examples, it being understood that the following drawings only illustrate some examples of the present invention and should not be construed as limiting the scope, and that other related drawings can be obtained from these drawings by those skilled in the art without the inventive effort. In the accompanying drawings:
FIG. 1 is a schematic diagram of a piping system for eliminating thermal fatigue of a nuclear power pipeline in some embodiments of the invention;
FIG. 2 is a schematic cross-sectional view of a second pipe thermal stratification region in a piping system for eliminating thermal fatigue of a nuclear power pipe in some embodiments of the present invention.
Detailed Description
For a clearer understanding of technical features, objects and effects of the present invention, a detailed description of embodiments of the present invention will be made with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are configured and operated in specific directions based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention, and do not indicate that the apparatus or element to be referred to must have specific directions, and thus should not be construed as limiting the present invention.
It should also be noted that unless explicitly stated or limited otherwise, terms such as "mounted," "connected," "secured," "disposed," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. When an element is referred to as being "on" or "under" another element, it can be "directly" or "indirectly" on the other element or one or more intervening elements may also be present. The terms "first," "second," "third," and the like are used merely for convenience in describing the present invention and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, whereby features defining "first," "second," "third," etc. may explicitly or implicitly include one or more such features. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
Referring to fig. 1 and 2, the present invention shows a piping system for removing thermal fatigue of nuclear power plant piping, for removing thermal fatigue caused by thermal stratification effect of the nuclear power plant piping, the nuclear power plant piping comprising a first piping 10 and at least one second piping 20 connected to and in communication with the first piping 10, the first piping 10 being capable of flowing a heating fluid, the heating fluid flowing in the first piping 10 during operation of the nuclear power plant, being affected by turbulent permeation and temperature heat transfer, and a portion of the heating fluid entering the second piping 20.
The number of the second pipes 20 may be two, and the two second pipes 20 may be disposed at both sides of the first pipe 10 and communicate with the first pipe 10, or the number of the second pipes 20 may be two or more, and the pipe diameters of the plurality of second pipes 20 may be the same or different.
The second pipes 20 have a thermal stratification region, such as an end of each second pipe 20 far from the first pipe 10 is connected to the cold pipe 40 through the isolation valve 30, the fluid in the second pipes 20 is in a low-speed or stagnation state, and natural convection occurs in the fluid region due to the heat dissipation of the wall surface of the second pipe 20 and the common influence of the cold fluid at the side of the isolation valve 30, and the region is the thermal stratification region. Wherein in this thermal stratification region the hot fluid flows upwards and the cold fluid flows downwards, and wherein the fluid experiences thermal stratification in the second pipe 20. Wherein, the mark A is a cold and hot fluid layering interface, and is a virtual interface, which is convenient for relieving fever layering phenomenon.
Further, the pipe system for eliminating thermal fatigue of a nuclear power pipe comprises:
a heat pipe device 50, wherein the heat pipe device 50 is arranged at the periphery of the part of the second pipeline 20 located in the thermal layering region;
and a temperature measuring device 60, the temperature measuring device 60 being disposed at an outer periphery of a portion of the second pipe 20 located at the thermally layered region, for detecting a temperature of the thermally layered region.
Understandably, the pipeline system for eliminating the nuclear power pipeline thermal fatigue is used for reducing the occurrence of thermal stratification, thermal circulation and thermal shock of the pipeline of the nuclear power plant, and can reduce the occurrence probability of pipeline fatigue, thereby improving the availability of the nuclear power unit, reducing the release risk of radioactive substances and improving the operation safety level of the nuclear power unit.
Further, the second pipe 20 may include a first branch pipe 21 and a second branch pipe 22, the first branch pipe 21 is connected to the first pipe 10, the second branch pipe 22 is connected to an end of the first branch pipe 21 remote from the first pipe 10, and the second branch pipe 22 has a thermal stratification region;
wherein the heat pipe device 50 and the temperature measuring device 60 are arranged on the periphery of the part of the second branch pipe 22 located in the thermal layering region.
Preferably, the first branch pipe 21 may be a vertical pipe, and the second branch pipe 22 may be a lateral pipe connected to the first branch pipe 21, and the lateral pipe may be larger than the first pipe 10.
In some embodiments, the nuclear power pipeline thermal fatigue relieving pipeline system includes a thermal insulation layer 70 disposed on the outer periphery of the nuclear power plant pipeline; the heat pipe device 50 and the temperature measuring device 60 are both arranged in the heat insulation layer 70.
Preferably, the insulating layer 70 is made of at least one of rock wool, aluminum silicate wool, glass wool or foam glass.
In some embodiments, the hot end of the heat pipe device 50 is in contact with the top of the second conduit 20 and the cold end of the heat pipe device 50 is in contact with the bottom of the second conduit 20. As can be appreciated, the two ends of the heat pipe device 50 (one end contacts the high temperature area at the top of the second pipe 20 and the other end contacts the low temperature area at the bottom of the second pipe 20) generate a temperature difference, and due to the characteristics of the heat pipe, the working medium in the heat pipe evaporates and absorbs heat at the hot end and condenses and releases heat at the cold end, so that the heat is continuously transferred from the hot end to the cold end, and the low temperature area is heated.
In some embodiments, the Heat Pipe apparatus 50 includes a plurality of Heat pipes 51, heat pipes (Heat Pipe): and heat exchange working medium is filled into the vacuum pipeline, and heat is transferred by evaporation and condensation. Each two heat pipes 51 are symmetrically disposed at the outer periphery of the second pipe 20 to form one heat pipe group, and a plurality of heat pipe groups are arranged along the axial direction of the second pipe 20.
In some embodiments, the amount of heat required to heat the fluid charge in the thermally stratified region is calculated by the following formula:
Q 1 ＝c·m·ΔT
wherein c is the specific heat of water; Δt: temperature difference of cold and hot fluid, Δt=t Thermal fluid -T Cold fluid The method comprises the steps of carrying out a first treatment on the surface of the m: the water quality of the heated pipe 51,
ρ cold fluid : cold fluid density; d: the pipe diameter of the layered pipeline; l: the length of the layered pipeline; and (3) injection: it is assumed that half of the stratified fluid is hot fluid and half is cold fluid.
The heat absorption capacity of the heat pipe is calculated by the following formula:
Q 2 ＝K·A·ΔT m ·t；
wherein, K: the heat transfer coefficient is determined according to the material of the heat pipe 51; a: total heat transfer area; delta T m : the logarithmic average temperature difference,
ΔT max ＝T thermal fluid -T 1 ；ΔT min ＝T Cold fluid -T 1 ；T 1 : the fluid saturation temperature in the heat pipe 51; t: heating time (supposing heating time, determining the number of heat pipes according to iterative calculation of the layered pipeline arrangement situation and the number of the heat pipes);
the number of heat pipes is calculated from the following formula:
wherein Q is 2 ＝η·Q 1 The eta heat loss coefficient is 0.98; f: heat transfer area of single heat pipeThe heat pipe is selected according to the form of the heat pipe, and the heat pipe can be square or oblate in order to increase the heat transfer area of the heat pipe.
In other embodiments, the heat pipe 51 is circular, square or oval in cross-section.
Preferably, the tubing for eliminating thermal fatigue of the nuclear power pipeline includes a thermal insulation layer 80 disposed about the periphery of the midsection of the heat pipe 51. The heat pipe 51 may include an arc portion, two ends of the arc portion are respectively provided with a protruding portion, two protruding portions are abutted against the outer surface of the second pipe 20, a groove structure is formed between the two protruding portions, and the heat insulating layer 80 may be a heat insulating sleeve, which is sleeved on a portion between the two protruding portions.
The insulating layer 80 is made of at least one of rock wool, aluminum silicate wool, glass wool or foam glass, but of course, the insulating layer 80 may be made of other materials, which are not particularly limited herein.
In some embodiments, the temperature measuring device 60 includes a plurality of temperature measuring units 61, and the plurality of temperature measuring units 61 are arranged along the axial direction and/or the circumferential direction of the second pipe 20 at the outer circumference of the second pipe 20 in the thermally layered region.
Preferably, the plurality of temperature measuring units 61 are symmetrically arranged along the axial direction of the second pipe 20 at the upper and lower outer surfaces of the second pipe 20 in the thermally layered region.
Preferably, the plurality of temperature measuring units 61 are symmetrically arranged along the axial direction of the second pipe 20 at the upper and lower outer surfaces of the second pipe 20 in the thermally layered region. For example, six temperature measuring units 61 may be provided, three temperature measuring units 61 are provided at the upper periphery of the second pipe 20, and the other three temperature measuring units 61 are provided at the lower periphery of the second pipe 20, and the temperature measuring units 61 provided up and down are symmetrically provided along the second pipe 20 to improve the accuracy of temperature detection. Of course, the number of the temperature measuring units 61 and the setting positions may be selected according to the actual requirements, and are not particularly limited herein.
In some embodiments, the temperature measuring unit 61 comprises a thermocouple or a thermal resistor. Understandably, the temperature measuring unit 61 is preferably a thermocouple. It is understood that the arrangement positions of the thermocouples/thermal resistors are determined by thermal calculation according to different positions and arrangement forms of the second pipe 20, and in order to accurately obtain the temperature difference between the upper wall surface and the lower wall surface of the second pipe 20, multiple groups of thermocouples/thermal resistors may be arranged on the upper wall surface and the lower wall surface of the second pipe 20.
In some embodiments, the temperature measuring device 60 is communicatively connected to a power plant master control to transmit detected temperature information to the power plant master control station, and to feed back measured temperatures to the operation and maintenance personnel to monitor the thermal stratification development and elimination.
Understandably, the pipeline system for eliminating the thermal fatigue of the nuclear power pipeline can utilize the self heat of the reactor coolant system to heat the pipeline in the relevant sensitive area in a passive mode, so that the thermal layering phenomenon is eliminated or relieved from the heat transfer mechanism, further, the thermal stress and the thermal fatigue effect are eliminated, and a guarantee is provided for the safe operation of the nuclear power plant and the prevention of the release of radioactivity.
It is to be understood that the above examples only represent preferred embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the invention; it should be noted that, for a person skilled in the art, the above technical features can be freely combined, and several variations and modifications can be made without departing from the scope of the invention; therefore, all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Claims (14)
1. A piping system for eliminating thermal fatigue of a nuclear power plant piping, for eliminating thermal fatigue caused by thermal stratification effect of the nuclear power plant piping, the nuclear power plant piping comprising a first piping (10) and at least one second piping (20) connected and in communication with the first piping (10), the second piping (20) having a thermal stratification region, characterized in that the piping system for eliminating thermal fatigue of the nuclear power piping comprises:
a heat pipe device (50), wherein the heat pipe device (50) is arranged on the periphery of the part of the second pipeline (20) located in the thermal layering region;
and the temperature measuring device (60) is arranged on the periphery of the part of the second pipeline (20) positioned in the thermal layering region and is used for detecting the temperature of the thermal layering region.
2. The nuclear power pipeline thermal fatigue eliminating pipeline system according to claim 1, wherein the hot end of the heat pipe device (50) is in contact with the top of the second pipeline (20), and the cold end of the heat pipe device (50) is in contact with the bottom of the second pipeline (20).
3. The piping system for eliminating thermal fatigue of nuclear power piping according to claim 2, wherein the heat pipe device (50) includes a plurality of heat pipes (51), each two heat pipes (51) being symmetrically disposed at an outer periphery of the second piping (20) to form a heat pipe group, the plurality of heat pipe groups being arranged in an axial direction of the second piping (20).
4. A nuclear power pipeline thermal fatigue removal pipeline system according to any of claims 1 to 3, wherein the amount of heat required for the fluid charge cooling fluid to be heated in the thermal stratification region is calculated by the following equation:
Q 1 ＝c·m·ΔT
wherein c is the specific heat of water; Δt: temperature difference of cold and hot fluid, Δt=t Thermal fluid -T Cold fluid The method comprises the steps of carrying out a first treatment on the surface of the m: the water quality of the heated pipe (51),
ρ cold fluid : cold fluid density; d: the pipe diameter of the layered pipeline; l: the length of the layered pipeline;
the heat absorption capacity of the heat pipe is calculated by the following formula:
Q 2 ＝K·A·ΔT m ·t；
wherein, K: the heat transfer coefficient is determined according to the material of the heat pipe (51); a: total heat transfer area; delta T m : the logarithmic average temperature difference,
ΔT max ＝T thermal fluid -T 1 ；ΔT min ＝T Cold fluid -T 1 ；T 1 : the saturation temperature of the fluid in the heat pipe (51); t: heating time;
the number of heat pipes is calculated from the following formula:
wherein Q is 2 ＝η·Q 1 The eta heat loss coefficient is 0.98; f: heat transfer area of a single heat pipe.
5. The piping system for eliminating thermal fatigue of nuclear power pipes according to claim 4, wherein the cross section of the heat pipe (51) is circular, square or oval.
6. The nuclear power pipeline thermal fatigue eliminating pipeline system according to claim 1, wherein the temperature measuring device (60) includes a plurality of temperature measuring units, the plurality of temperature measuring units being arranged at an outer periphery of the thermal stratification region of the second pipeline (20) along an axial direction and/or a circumferential direction of the second pipeline (20).
7. The nuclear power pipeline thermal fatigue eliminating pipeline system according to claim 6, wherein a plurality of the temperature measuring units are symmetrically arranged along an axial direction of the second pipeline (20) at upper and lower outer surfaces of the second pipeline (20) at the thermal stratification region.
8. The nuclear power pipeline thermal fatigue eliminating pipeline system according to claim 6, wherein the temperature measuring unit includes a thermocouple or a thermal resistor.
9. The nuclear power pipeline thermal fatigue eliminating pipeline system according to claim 6, wherein the temperature measuring device (60) is in communication connection with a power plant main control.
10. The nuclear power pipeline thermal fatigue removal pipeline system of claim 4, wherein the nuclear power pipeline thermal fatigue removal pipeline system comprises an insulation layer (70) arranged on the periphery of the nuclear power plant pipeline;
the heat pipe device (50) and the temperature measuring device (60) are both arranged in the heat insulation layer (70).
11. The nuclear power pipeline thermal fatigue eliminating pipeline system according to claim 10, wherein the insulating layer (70) is made of at least one of rock wool, aluminum silicate wool, glass wool or foam glass.
12. The nuclear power pipeline thermal fatigue eliminating pipeline system according to claim 4, wherein the nuclear power pipeline thermal fatigue eliminating pipeline system comprises a heat insulating layer (80) arranged on the periphery of the middle section of the heat pipe (51).
13. The nuclear power pipeline thermal fatigue eliminating pipeline system according to claim 12, wherein the insulating layer (80) is made of at least one of rock wool, aluminum silicate wool, glass wool or foam glass.
14. The piping system for eliminating thermal fatigue of a nuclear power pipeline according to claim 1, wherein,
the second pipeline (20) comprises a first branch pipe (21) and a second branch pipe (22), the first branch pipe (21) is connected with the first pipeline (10), the second branch pipe (22) is connected with one end of the first branch pipe (21) far away from the first pipeline (10), and the second branch pipe (22) is provided with the thermal layering region;
the heat pipe device (50) and the temperature measuring device (60) are arranged on the periphery of the part, located in the thermal layering region, of the second branch pipe (22).
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