A reversible rainproof awning for protecting nuclear power equipment

Abstract

A reversible rainproof canopy for protecting nuclear power equipment. The rainproof canopy includes: a leg, which is arranged on opposite sides of the main valve from the guardrail, the lower end of the leg has a foot, and the upper end of the leg has two connecting parts; a roof, which has a frame and a rain shield; the frame has two first connecting rods, two second connecting rods and a shielding part; the two first connecting rods are respectively rotatably connected to the two connecting parts; the two second connecting rods are respectively used for detachable connection with the guardrail; when the two second connecting rods are respectively connected to the guardrail, the shielding part is located above the main valve and tilted downward toward one side of the leg. In this way, when the main valve is repaired, the roof can be flipped up by only disassembling the second connecting rod and the guardrail for easy maintenance, saving a lot of maintenance time and maintenance labor costs. At the same time, the rainproof canopy meets the requirements of on-site earthquake resistance II through reasonable structural design, and the overall appearance is simple and generous, which is conducive to standardized management on site.

Description

Technical Field

[0001] The invention relates to the field of nuclear power plant safety technology, in particular to nuclear power plant protection equipment, and more particularly to a reversible rainproof shed for protecting nuclear power equipment. Background Art

[0002] The main valves of CGN's nuclear power VVP system are all produced by FLOWSERVE in the United States, and all components are supplied as a complete set by the equipment manufacturer. The main function of this equipment is to implement the rapid isolation of the main steam system and serve as part of the containment, the third barrier (i.e. the last barrier) of nuclear safety in nuclear power plants. Since the equipment is installed on the top of the nuclear island and there is no roof on the top, a rain shelter is required to prevent rain from wetting the equipment and causing the instrumentation and control equipment to become unavailable (see Figure 1 ).

[0003] The current problem is:

[0004] 1) The existing rain shelter is welded with Q235B and fixed with bolts. The rain shelter needs to be completely removed every time the VVP main valve is inspected, which will undoubtedly seriously restrict the main line construction period, especially during emergency repair work, the delay caused by the removal of the rain shelter is more prominent;

[0005] 2) The safety level of the VVP main valve is level 2 and the seismic level is level 1I, but the structural design of the existing rain shelter does not meet the requirements of the main valve seismic level 1I. Under earthquake conditions, the rain shelter may collapse, introducing internal projectiles and accidentally hitting sensitive equipment on the main valve, causing the unit to shut down;

[0006] 3) The structure of the rain shelter is simple and unsightly, which is not conducive to the standardization of the site. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a reversible rainproof shed for protecting nuclear power equipment which is shockproof, reversible and beautiful in appearance, in view of the above-mentioned problems in the prior art.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: to provide a reversible rainproof canopy for protecting nuclear power equipment, the VVP main valve equipment includes a main valve and a guardrail fixed on one side of the main valve, and the rainproof canopy includes:

[0009] A leg portion, which is arranged on two opposite sides of the main valve from the guardrail, wherein the lower end of the leg portion has a foot for fixedly connecting to the ground, and the upper end of the leg portion has two connecting portions;

[0010] A ceiling having a frame and a rain shield covering the frame; the frame having two first connecting rods, two second connecting rods and shielding parts respectively connected to the two first connecting rods and the two second connecting rods on opposite sides; the two first connecting rods are respectively rotatably connected to the two connecting parts; the two second connecting rods are respectively used for detachable connection with the guardrail; when the two second connecting rods are respectively connected to the guardrail, the shielding part is located above the main valve and tilted downward toward one side of the leg.

[0011] In the reversible rainproof canopy for protecting nuclear power equipment provided by the present invention, the connecting part includes two opposite and spaced-apart connecting plates, the corresponding first connecting rod is inserted between the two connecting plates, and the first connecting rod and the two connecting plates are connected by upper and lower bolts.

[0012] In the flippable rainproof canopy for protecting nuclear power equipment provided by the present invention, two stop portions are provided at the upper ends of the legs, and the two stop portions correspond one-to-one to the two connecting portions respectively; the stop portions are used to abut against the first connecting rod rotatably connected to the corresponding connecting portion during the process of the ceiling flipping upward around the upper ends of the legs; when the first connecting rod abuts against the stop portions, the ceiling does not block the main valve.

[0013] In the flip-over rainproof canopy for protecting nuclear power equipment provided by the present invention, the legs include the ground feet, two support rods respectively connected vertically to the ground feet, and a reinforcing rod connected between the two support rods; the upper end of each support rod has a connecting portion; the four side walls of the support rod are respectively connected to the ground feet through a reinforcing plate.

[0014] In the flippable rainproof canopy for protecting nuclear power equipment provided by the present invention, the stop portion is arranged at the upper end of the support rod, and includes a stop plate and a support plate. The stop plate is parallel to the horizontal plane and vertically connected to the side wall of the support rod facing away from the main valve, and the support plate is parallel to the vertical plane and vertically connected to the lower side of the stop plate and the side wall of the support rod facing away from the main valve, respectively.

[0015] In the reversible rainproof canopy for protecting nuclear power equipment provided by the present invention, the legs and the frame are made of aluminum alloy profiles; the rain shield is made of corrugated board, double-sided rubber-lined oil-proof and fire-proof canvas or carbon fiber board.

[0016] In the reversible rainproof canopy for protecting nuclear power equipment provided by the present invention, the shielding part includes a main frame; the main frame includes a first longitudinal main beam and a second longitudinal main beam that are parallel, spaced and aligned, a first transverse main beam, a second transverse main beam and a third transverse main beam that are respectively vertically connected to the first longitudinal main beam and the second longitudinal main beam at both ends, two first reinforcing beams that are respectively vertically connected to the first transverse main beam and the second transverse main beam at both ends, and two second reinforcing beams that are respectively vertically connected to the second transverse main beam and the third transverse main beam at both ends; the second transverse main beam is located between the first transverse main beam and the third transverse main beam, and the first transverse main beam, the second transverse main beam and the third transverse main beam are arranged at equal intervals; the distance between the two first reinforcing beams, the distance between the first longitudinal main beam and the adjacent first reinforcing beam, and the distance between the second longitudinal main beam and the adjacent first reinforcing beam are equal; the two second reinforcing beams are respectively aligned one by one with the two first reinforcing beams; and the two second connecting rods are respectively connected and vertically connected to the lower side of the second longitudinal main beam.

[0017] In the reversible rainproof canopy for protecting nuclear power equipment provided by the present invention, the lower side of the second longitudinal main beam has two fixing parts, and two second connecting rods are respectively connected to the two fixing parts; the fixing part includes two parallel and spaced fixing plates respectively connected vertically to the lower side of the second longitudinal main beam, the second connecting rod includes a column and a base plate, the upper end of the column is inserted between the two fixing plates of the corresponding fixing part and is connected to the two fixing plates through upper and lower bolts, the lower end of the column is vertically connected to the base plate, and the base plate is used to be connected to the guardrail through bolts.

[0018] In the reversible rainproof canopy for protecting nuclear power equipment provided by the present invention, the shielding part also includes a sub-frame connected to the main frame; the sub-frame includes a first vertical rod, a second vertical rod and a third vertical rod respectively connected vertically to the lower side of the first longitudinal main beam, a longitudinal rod simultaneously connected vertically to the first vertical rod, the second vertical rod and the third vertical rod, a first oblique rod connected to the first transverse main beam at one end and the longitudinal rod at the other end, and a second oblique rod connected to the third transverse main beam at one end and the longitudinal rod at the other end; the first vertical rod, the second vertical rod and the third vertical rod are respectively aligned one by one with the first transverse main beam, the second transverse main beam and the third transverse main beam; the first oblique rod is parallel to the second oblique rod; the upper ends of the two first connecting rods are respectively connected vertically to the lower side of the longitudinal rod, and the interval between the two first connecting rods is smaller than the distance between the first vertical rod and the third vertical rod.

[0019] In the reversible rainproof canopy for protecting nuclear power equipment provided by the present invention, the angle between the first oblique rod and the first connecting rod is between 104° and 124°.

[0020] The following beneficial effects can be achieved by implementing the reversible rainproof canopy for protecting nuclear power equipment provided by the present invention:

[0021] 1. The rainproof canopy includes: a leg, which is arranged on two opposite sides of the main valve from the guardrail, the lower end of the leg has a foot for fixed connection with the ground, and the upper end of the leg has two connecting parts; a ceiling, which has a frame and a rain shield covering the frame; the frame has two first connecting rods, two second connecting rods and shielding parts respectively connected to the two first connecting rods and the two second connecting rods on opposite sides; the two first connecting rods are respectively rotatably connected to the two connecting parts; the two second connecting rods are respectively used for detachable connection with the guardrail; when the two second connecting rods are respectively connected to the guardrail, the shielding part is located above the main valve and tilted downward toward one side of the leg. In this way, when the main valve is repaired, the ceiling can be turned up for easy maintenance by only disassembling the second connecting rod and the guardrail, while the existing rainproof canopy needs to be completely dismantled when the main valve is repaired. In comparison, a lot of maintenance time and maintenance labor costs are saved;

[0022] 2. The rainproof shed meets the requirements of on-site earthquake resistance II through reasonable structural design;

[0023] 3. The overall appearance of the rain shelter is simple and elegant, which is conducive to standardized management on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a usage scenario diagram of a rainproof awning in the prior art;

[0025] Figure 2 A schematic diagram of the three-dimensional structure of a rainproof shed provided for a preferred embodiment of the present invention, in which the rain shield is omitted;

[0026] Figure 3 A schematic side view of a rain shelter provided for a preferred embodiment of the present invention;

[0027] Figure 4 Dimensional diagram (I) of a rain shelter provided for a preferred embodiment of the present invention, the dimensions in the diagram are in mm;

[0028] Figure 5 Dimensional marking diagram (II) of a rainproof awning provided for a preferred embodiment of the present invention, the dimensions in the diagram are in mm;

[0029] Figure 6 Finite element model diagram;

[0030] Figure 7 Boundary condition diagram;

[0031] Figure 8.1 von Mises stress cloud diagram of the rain shelter (unit: kPa);

[0032] Figure 8.2 It is the displacement cloud map of the rain shelter (unit: mm);

[0033] Figure 8.3 This is the stress cloud diagram of the bolt connection of the rainproof awning column (unit: kPa);

[0034] Figure 8.4 It is the stress cloud diagram of the ground connection of the rain shelter column (unit: kPa);

[0035] Figure 8.5 It is the stress cloud diagram of the ground connection of the rain shelter column (unit: kPa);

[0036] Figure 8.6 von Mises stress cloud diagram of the rain shelter (unit: kPa);

[0037] Figure 8.7 It is the displacement cloud map of the rain shelter (unit: mm);

[0038] Figure 8.8 This is the stress cloud diagram of the bolt connection of the rainproof awning column (unit: kPa);

[0039] Figure 8.9 It is the stress cloud diagram of the ground connection of the rain shelter column (unit: kPa);

[0040] Figure 8.10 This is the stress cloud diagram of the ground connection of the canopy column (unit: kPa).

[0041] Description of the accompanying drawings for the specific implementation:

[0042] Legs 1 ceiling 2 First connecting rod 211 Second connecting rod 212 Footing 11 Support rod 12 Connector 1211 Reinforcement sheet 13 Stopper 1221 Support sheet 1222 The first longitudinal beam 2131a Second longitudinal main beam 2131b The first transverse beam 2132a Second transverse main beam 2132b The third transverse main beam 2132c First reinforcement beam 2133a Second reinforcement beam 2133b Reinforcement rod 14 Fixed plate 2134 Column 2121 Base Plate 2122 First vertical rod 2135a Second vertical rod 2135b The third vertical rod 2135c Longitudinal rod 2136 First diagonal rod 2137a Second diagonal rod 2137b DETAILED DESCRIPTION

[0043] 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. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] like Figures 2 to 3 As shown, it is a preferred embodiment of the reversible rainproof canopy for protecting nuclear power equipment provided by the present invention.

[0045] First of all, it should be noted that those skilled in the art should know that the VVP main valve device usually includes a main valve and a guardrail fixed to one side of the main valve.

[0046] The rainproof canopy provided in this embodiment includes a leg 1 and a ceiling 2. The leg 1 and the guardrail are arranged on opposite sides of the main valve, the lower end of the leg 1 has a foot 11 for fixed connection with the ground, and the upper end of the leg 1 has two connecting parts. The ceiling 2 has a frame and a rain shield covering the frame; the frame has two first connecting rods 211, two second connecting rods 212 and shielding parts respectively connected to the two first connecting rods 211 and the two second connecting rods 212 on opposite sides; the two first connecting rods 211 are respectively rotatably connected to the two connecting parts; the two second connecting rods 212 are respectively used for detachable connection with the guardrail; when the two second connecting rods 212 are respectively connected to the guardrail, the shielding part is located above the main valve and tilted downward toward one side of the leg 1.

[0047] In this embodiment, the second connecting rod 212 and the guardrail are detachably connected via bolts.

[0048] In this embodiment, the connecting portion includes two connecting pieces 1211 that are opposite and spaced apart, and the corresponding first connecting rod 211 is inserted between the two connecting pieces 1211 . The first connecting rod 211 and the two connecting pieces 1211 are connected by two upper and lower bolts.

[0049] In this way, when the main valve needs to be repaired, it is only necessary to remove the bolts between the second connecting rod 212 and the guardrail first, and then remove the bolts between the first connecting rod 211 and the connecting piece 1211, so as to realize the flipping of the roof 2. It should be noted here that each of the first connecting rods 211 has two bolts, one on the upper side and the other on the lower side. We need to remove the bolt on the upper side of the first connecting rod 211, and then loosen the bolt on the lower side by a few buckles to prevent the bolts from being too tight, which is not conducive to the flipping of the roof 2.

[0050] To ensure the safety of the operation, prepare one person each on the front, back, left and right sides of the awning, and the people on the left and right need to stand on the stepladder. When flipping, the person in front of the awning (the side close to the guardrail) should first gently lift the awning by himself. (If it is very strenuous, it may be that the bolt below the flipping part that has not been removed is too tight, and you can loosen it a little bit. But it cannot be too loose, otherwise the speed will be difficult to control during flipping. Then the two people on the left and right are now the main force, slowly flipping the roof 2. When the flipping is almost in place, the person behind can also join in. The main thing for the person behind is to control the flipping speed not to be too fast. Finally, the three people on the left, right, and back coordinate the work, flip the roof 2 to a fixed position, and put it down steadily and flat. Note: Do not be impatient during the entire flipping process, handle it with care, operate slowly, and safety first.

[0051] During the restoration, adhering to the principle of safety first, one person needs to stand in front, behind, left and right during the operation, and the people on the left and right need to stand on the stepladder. During the operation, the person at the back should first use force to lift up the ceiling 2, and then the three people on the left, right and back should coordinate and slowly turn over the ceiling 2. Pay attention to control the speed, not too fast. After turning over halfway, the person on the top can join in. At this time, the three people on the top, left and right coordinate the work, put the ceiling 2 back to its original position, and then restore and tighten the bolts.

[0052] In some embodiments, we can replace the bolts connecting the first connecting rod 211 and the lower sides of the two connecting plates 1211 with pins, so as to ensure the connection and avoid the bolts being pressed too tight, which is not conducive to flipping.

[0053] In this embodiment, two stop portions are provided at the upper end of the leg 1, and the two stop portions correspond to the two connecting portions one by one respectively; the stop portions are used to support the first connecting rod 211 rotatably connected to the corresponding connecting portion during the process of the ceiling 2 flipping upward around the upper end of the leg 1; when the first connecting rod 211 is supported by the stop portions, the ceiling 2 does not block the main valve.

[0054] In this way, each time the roof 2 is turned over, it can be ensured that the roof 2 is turned over in place. Most importantly, the stopper can prevent the roof 2 from tipping over to the extent of damaging the first connecting rod 211 or the connecting portion due to improper operation during the turning operation of the roof 2.

[0055] In some embodiments, we can also set a buffer on the upper side of the stopper, and the buffer can be an elastic object such as a spring or rubber. Therefore, during the flipping process, when the first connecting rod 211 of the roof 2 accidentally collides with the stopper, the buffer can play a buffering role and well protect the first connecting rod 211 and the stopper.

[0056] In this embodiment, the leg 1 includes the foot 11, two support rods 12 respectively connected to the foot 11 vertically, and a reinforcing rod 14 connected between the two support rods 12; the upper end of each support rod 12 has a connecting portion; the four side walls of the support rod 12 are respectively connected to the foot 11 through a reinforcing sheet 13. Specifically, the two support rods 12 are connected to the same foot 11, the support rod 12 is in the shape of a rectangular parallelepiped, the reinforcing sheet 13 is in the shape of a right triangle, and the support rod 12, the reinforcing sheet 13 and the foot 11 are fixedly connected by welding. The opposite ends of the foot 11 are fixedly connected to the ground by four bolts.

[0057] In some embodiments, the support rod 12 can be in the form of a pentagonal prism, a hexagonal prism, or an n-prism, where n is a natural number greater than or equal to 6. In these embodiments, the n side walls of the support rod 12 are respectively connected to the foot 11 through a reinforcing sheet 13, that is, the support rod 12 and the foot 11 are connected and fixed through n reinforcing sheets 13 to form a more secure connection.

[0058] In this embodiment, the stop portion is arranged at the upper end of the support rod 12, and includes a stop plate 1221 and a support plate 1222. The stop plate 1221 is parallel to the horizontal plane and vertically connected to the side wall of the support rod 12 facing away from the main valve, and the support plate 1222 is parallel to the vertical plane and vertically connected to the lower side of the stop plate 1221 and the side wall of the support rod 12 facing away from the main valve, respectively.

[0059] The shielding portion includes a main frame; the main frame includes a first longitudinal main beam 2131a and a second longitudinal main beam 2131b that are parallel, spaced and aligned, a first transverse main beam 2132a, a second transverse main beam 2132b and a third transverse main beam 2132c that are respectively connected perpendicularly to the first longitudinal main beam 2131a and the second longitudinal main beam 2131b at both ends, a first reinforcing beam 2133a that is respectively connected perpendicularly to the first transverse main beam 2132a and the second transverse main beam 2132b at both ends, and a second reinforcing beam 2133b that is respectively connected perpendicularly to the second transverse main beam 2132b and the third transverse main beam 2132c at both ends; the second transverse main beam 2132b is located at the first Between the transverse main beam 2132a and the third transverse main beam 2132c, the first transverse main beam 2132a, the second transverse main beam 2132b and the third transverse main beam 2132c are arranged at equal intervals; the distance between the two first reinforcing beams 2133a, the distance between the first longitudinal main beam 2131a and the adjacent first reinforcing beam 2133a, and the distance between the second longitudinal main beam 2131b and the adjacent first reinforcing beam 2133a are equal; the two second reinforcing beams 2133b are respectively aligned one by one with the two first reinforcing beams 2133a; and the two second connecting rods 212 are respectively connected and vertically connected to the lower side of the second longitudinal main beam 2131b.

[0060] The lower side of the second longitudinal main beam 2131b is provided with two fixing parts, and the two second connecting rods 212 are respectively connected to the two fixing parts; the fixing part includes two parallel and spaced fixing plates 2134 respectively connected vertically to the lower side of the second longitudinal main beam 2131b, the second connecting rod 212 includes a column 2121 and a base plate 2122, the upper end of the column 2121 is inserted between the two fixing plates 2134 of the corresponding fixing part and is connected to the two fixing plates 2134 through upper and lower bolts, the lower end of the column 2121 is vertically connected to the base plate 2122, and the base plate 2122 is used to be connected to the guardrail through bolts.

[0061] The shielding portion also includes a sub-frame connected to the main frame; the sub-frame includes a first vertical rod 2135a, a second vertical rod 2135b and a third vertical rod 2135c respectively connected vertically to the lower side of the first longitudinal main beam 2131a, and a longitudinal rod 2136 vertically connected to the first vertical rod 2135a, the second vertical rod 2135b and the third vertical rod 2135c, a first oblique rod 2137a connected at one end to the first transverse main beam 2132a and at the other end to the longitudinal rod 2136, and a first oblique rod 2137a connected at one end to the third transverse main beam 2132c and at the other end to the longitudinal rod 21 36; the first vertical rod 2135a, the second vertical rod 2135b and the third vertical rod 2135c are respectively aligned with the first transverse main beam 2132a, the second transverse main beam 2132b and the third transverse main beam 2132c; the first oblique rod 2137a is parallel to the second oblique rod 2137b; the upper ends of the two first connecting rods 211 are respectively vertically connected to the lower sides of the longitudinal rods 2136, and the interval between the two first connecting rods 211 is smaller than the distance between the first vertical rod 2135a and the third vertical rod 2135c.

[0062] In this embodiment, the angle between the first oblique rod 2137a and the first connecting rod 211 is 114°.

[0063] In some embodiments, the angle between the first oblique rod 2137a and the first connecting rod 211 may be 104°, 109°, 119° or 124°.

[0064] In this embodiment, the leg 1 and the frame are made of aluminum alloy profiles; the rain shield is made of corrugated board, double-sided rubber-lined oil-proof and fire-proof canvas or carbon fiber board. Preferably, the leg 1 and the frame are made of 7075 special aluminum alloy profiles. Preferably, the rain shield is made of 0.6mm thick corrugated board, 0.9mm thick double-sided rubber-lined oil-proof and fire-proof canvas or high-strength carbon fiber board.

[0065] In this embodiment, the bolt type between the support rod 12 and the first connecting rod 211 is preferably 4-M16x90, the bolt type between the fixing plate 2134 and the second connecting rod 212 is preferably 4-M12x90, the bolt type between the bottom plate 2122 and the guardrail is preferably 4-M12x30, and the bolt type between the foot 11 and the ground is 8-M20x45. In addition, the size design of the rain shelter is as follows Figure 4 and Figure 5 shown.

[0066] In order to prove that the rain shelter provided in this embodiment meets the requirements of on-site earthquake resistance, the applicant uses finite element analysis to calculate the impact of the rain shelter in earthquake conditions. The calculation process and results are described as follows.

[0067] 1. Calculation Basis

[0068] Calculation standards and related technical information:

[0069] GB50267-97 Nuclear Power Plant Seismic Design Code

[0070] GB 50429-2007 Aluminum Alloy Structure Design Code

[0071] GB / T 3880.2-2012 Aluminium and aluminium alloy plates and strips for general industrial use Part 2: Mechanical properties

[0072] GB50017-2003 Code for Design of Steel Structures

[0073] 《Electrical and connection building floor response spectrum for units 1 and 2》

[0074] 2. Calculation Instructions

[0075] (1) Finite element calculation software

[0076] The finite element calculation software used was ANSYS12.1.

[0077] (2) Calculation method

[0078] Structural static calculation, modal analysis and spectral analysis are used. The result is the superposition of spectral analysis and static analysis results.

[0079] (3) Damping coefficient

[0080] Operational Base Earthquake (OBE) seismic damping ratio is 2%

[0081] Safe shutdown earthquake (SSE) earthquake damping ratio is 4%

[0082] (4) Mode combination

[0083] The synthesis of horizontal and vertical seismic spectra uses the CQC method to fully combine the quadratic terms of the two directional spectral responses.

[0084] (5) Contents of seismic calculation

[0085] Strength and stiffness of rain shelter under combined static and seismic response.

[0086] (6) Earthquake calculation conditions

[0087] Working status of rain shelter, calculate two working conditions: OBE and SSE.

[0088] 3. Calculation and Judgment Criteria

[0089] (1) Material parameters

[0090] Material: 7075, elastic modulus: E = 70GPa, Poisson's ratio: μ = 0.3

[0091] According to GB / T 3880.2-2012 General Industrial Aluminum and Aluminum Alloy Plates and Strips Part 2: Mechanical Properties, the mechanical properties of the materials are shown in Table 4.1:

[0092] Table 4.1 Mechanical properties of materials

[0093] Material Thickness(mm) Tensile strength(MPa) Specified non-proportional elongation strength (MPa) 7075 >3～6 545 475 7075 >3～12.5 540 460

[0094] According to GB / T3098.1-2010 Mechanical properties of fasteners - bolts, screws and studs, the mechanical properties of bolts are shown in Table 4.2:

[0095] Table 4.2 Mechanical properties of bolts

[0096] Bolt specifications Bolt grade Tensile strength(MPa) Yield strength(MPa) M12 8.8 800 640 M16 8.8 800 640 M20 8.8 800 640

[0097] (2) Load combination

[0098] Self-weight load and seismic load are taken into account in the calculation.

[0099] (3) Stress assessment method for linear supports

[0100] The main structure of this component is a linear support. The relevant provisions of RCC-M Part H can be used for stress calculation and assessment. Combined with the description of RCC-M Appendix Z, the specific method of structural stress assessment is as follows:

[0101] Tensile stress

[0102] F t =min{0.60S y ,0.50S u}×r=270×1.4=378MPa (1)

[0103] Bending stress

[0104] F b =min{0.60S y ,0.50S u}×r=270×1.4=378MPa (2)

[0105] Shear stress

[0106] F v =min{0.40S y,0.33S u}×r=178×1.4=249MPa (3)

[0107] Composite stress: composite of axial stress and bending stress

[0108]

[0109] Where: S y is the material yield strength

[0110] S u The tensile strength of the material

[0111] f t is the calculated axial stress;

[0112] f by ,f bz is the calculated bending stress of the two cross-section inertia planes.

[0113] The coefficient r is determined by the following formula:

[0114]

[0115] The specific method of structural stress assessment is shown in Table 4.3:

[0116] Table 4.3 Structural stress assessment method

[0117]

[0118] (4) Bolt stress assessment method

[0119] The connecting bolts in this component are mainly subjected to shearing. The relevant provisions of Part H of RCC-M can be used for stress calculation and assessment. Combined with the description of Part Z of RCC-M, the specific method of stress assessment is as follows:

[0120] Shear stress

[0121] F vb =S u / 8=800 / 8=100MPa

[0122] 4. Floor Response Spectrum

[0123] The floor response spectra of the electrical and connection building of Unit 1 are shown in Tables 5.1 and 5.2.

[0124] Table 5.1 Floor response spectrum (OBE)

[0125]

[0126] Table 5.2 Floor response spectrum (SSE)

[0127]

[0128]

[0129] 5. Finite Element Method and Analysis Theory

[0130] 5.1 Introduction to Finite Element Method

[0131] The finite element method is a numerical solution method that discretizes a continuum into a finite number of units and performs piecewise interpolation on these units to solve problems such as the static and dynamic mechanical properties of a structure.

[0132] The basic idea of ​​finite element method is:

[0133] (1) The complex structure is discretized into numerous simple-shaped, small enough units whose characteristic parameters can be described by simple mathematical models. The units are connected by nodes.

[0134] (2) Unit analysis, that is, through the study of units, the relationship equations between stress, strain, nodal force and nodal displacement components are established.

[0135] (3) Based on the unit analysis results, and in the case of determining the boundary conditions, all units are reassembled into an overall finite element equation set, i.e., a matrix equation, according to the original structure, based on the equilibrium conditions and continuity conditions of the structural forces. This analysis process is called overall analysis.

[0136] (4) Select an appropriate calculation method based on the specific characteristics of the matrix equation to find the solution to the matrix equation.

[0137] Advantages of the finite element method:

[0138] (1) Applicable to structures with complex geometric shapes. In actual engineering analysis, we often encounter some complex actual structures. In solid mechanics and other continuum mechanics, it is impossible to obtain analysis results. However, the finite element method can effectively analyze these structures.

[0139] (2) Simple method of introducing boundary conditions. All units of the structure use the same displacement function. The boundary conditions and individual finite element equations are independent of each other. When the boundary conditions change, the displacement function does not need to be changed. This greatly simplifies the compilation of general finite element programs.

[0140] (3) It can handle a variety of physical problems. The finite element method can handle static problems, dynamic problems, fluid mechanics problems, thermal problems, electromagnetic field problems, acoustic problems, and coupled field problems.

[0141] (4) The current common finite element analysis software performs finite element calculations based on correct modeling. Not only are the calculation results more accurate, but the stress, strain and displacement distribution of the entire structure can also be displayed very intuitively in the form of charts or curves. The finite element method can be divided into linear finite element method and nonlinear finite element method according to its application in different projects. The linear finite element method can be further divided into static and dynamic finite element methods.

[0142] 5.2 Overview of Modal Analysis Theory

[0143] Modal analysis is an analysis method used to study the vibration characteristics (natural modal frequency and vibration mode) of a structure or component. In the design of structures subjected to dynamic loads, natural modal frequency and vibration mode are very important parameters. In addition, dynamic modal analysis is also a necessary step before conducting other dynamic analyses (transient analysis, harmonic response analysis, and spectral analysis, etc.).

[0144] Modal analysis can effectively prevent the designed structure from resonating or vibrating at a specific frequency. Engineers can clearly understand the response of the structure under different types of dynamic loads based on the analysis results. It is also very helpful for solving control parameters such as time step in subsequent dynamic analysis. The structure will produce different responses under different dynamic loads. This is the vibration characteristic of the structure. Therefore, it is very necessary to obtain the vibration characteristics of the structure through modal analysis before preparing for other dynamic analysis.

[0145] 5.3 Overview of Spectral Analysis Theory

[0146] Spectral analysis is an analytical method that links the results of modal analysis with known spectra to calculate the structural response. It is mainly used to determine the dynamic response of the structure to random loads or random time-varying loads (earthquakes, wind loads, ocean waves, rocket engine vibrations, etc.). Spectral analysis can be divided into time-history analysis and frequency-domain spectral analysis. Time-history spectral analysis is mainly used for transient dynamic analysis.

[0147] 5.4CQC Synthesis

[0148] CQC is the complete quadratic term combination method, which not only takes into account the square terms of each main vibration mode, but also the coupling terms. For more complex structures, such as structures considering transverse torsional coupling, the results of using the complete quadratic term combination are more accurate.

[0149] 6. Finite element model

[0150] The main structure of the rainproof shed provided in this embodiment has an aluminum profile structure. The finite element modeling adopts BEAM188 units as a whole and SHELL63 units in parts. The finite element model of the whole machine is shown in Figure 6 .

[0151] The four legs constrain three degrees of freedom of displacement. The main structure's deadweight is applied through gravity acceleration. The top cover is not reflected in the model. The deadweight of the top cover is 10kg and is evenly distributed on the 12 cross nodes of the top frame through mass units. The application of boundary conditions can be seen in Figure 7 .

[0152] 7. Finite element calculation results

[0153] 7.1 Modal calculation

[0154] ANSYS software was used to perform modal analysis on the canopy structure, and a total of 80 vibration modes were calculated. The data of the vibration modes with mass participation coefficients exceeding 90% in the three translational directions were summarized and shown in Table 8.1.

[0155] Select the data with calculation frequency within 100Hz for listing.

[0156] Through ANSYS calculation, the modal mass participation coefficients in the three translational degrees of freedom directions are obtained, see Table 8.2.

[0157] Table 8.1 Table of vibration mass participation coefficients

[0158] project Modal mass participation factor Corresponding calculation frequency order Sum UX 0.949 9 Sum U 0.906 54 Sum U 0.943 6

[0159] Note: Sum UX, Sum UY and Sum UZ are the cumulative percentage values ​​of the modal mass participation coefficients in the three directions of X, Y and Z of the overall coordinate system.

[0160] Table 8.2 Frequency and vibration mass participation coefficient information table

[0161]

[0162]

[0163] 7.2 Earthquake Calculation

[0164] The following earthquake calculation results take into account the influence of the self-weight of the canopy during an earthquake. The stress shown in the picture is the von Mise stress, and the data in the table are the extracted partial stresses.

[0165] (1) OBE calculation results are as follows Figure 8.1 to Figure 8.5 As shown;

[0166] (2) The SSE calculation results are as follows Figures 8.6 to 8.10 shown.

[0167] 7.3 Summary of results

[0168] The calculation results are summarized in Table 8.3.

[0169] Table 8.3 Summary of calculation results

[0170] Working conditions Maximum displacement(mm) Maximum von Mises stress (MPa) OBE 0.97 84.11 SSE 0.97 84.24

[0171] 7.4 Calculation conclusion

[0172] According to the calculation data in Table 8.4, under the OBE and SSE conditions, the allowable stress ratios of each partial stress and composite stress are less than 1, meeting the seismic requirements.

[0173] Table 8.4 Structural stress assessment

[0174]

[0175] 8. Bolt force calculation

[0176] According to the force extracted from the finite element calculation results, the M16 bolt between the upper and lower sections of the column is subjected to the greatest force. Based on conservative considerations, the shear force borne by one bolt is 25566N.

[0177] Shear stress caused by shear force:

[0178]

[0179] A e —Effective area at a single bolt thread, mm 2 ;

[0180] n—number of shear planes;

[0181] d e —Effective diameter at the thread, i.e. the minor diameter of the bolt, mm;

[0182] The bolt design meets the strength requirements.

[0183] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A reversible rainproof canopy for protecting nuclear power equipment, applied to VVP main valve equipment, the VVP main valve equipment comprising a main valve and a guardrail fixed to one side of the main valve, characterized in that: The rainproof canopy comprises: The leg part (1) and the guardrail are arranged on two opposite sides of the main valve, the lower end of the leg part (1) has a foot (11) for fixedly connecting to the ground, and the upper end of the leg part (1) has two connecting parts; A ceiling (2) comprising a frame and a rain shield covering the frame; the frame comprising two first connecting rods (211), two second connecting rods (212), and shielding portions respectively connected to the two first connecting rods (211) and the two second connecting rods (212) on opposite sides; the two first connecting rods (211) are respectively rotatably connected to the two connecting portions; the two second connecting rods (212) are respectively used for detachably connecting to the guardrail; when the two second connecting rods (212) are respectively connected to the guardrail, the shielding portion is located above the main valve and tilted downward toward one side of the leg portion (1); The connecting portion comprises two connecting pieces (1211) that are opposite and spaced apart, the corresponding first connecting rod (211) is inserted between the two connecting pieces (1211), and the first connecting rod (211) and the two connecting pieces (1211) are connected via two upper and lower bolts; Two stop portions are provided at the upper end of the leg portion (1), and the two stop portions correspond to the two connecting portions one by one respectively; the stop portions are used to abut against a first connecting rod (211) rotatably connected to the corresponding connecting portion when the ceiling (2) is turned upward around the upper end of the leg portion (1); when the first connecting rod (211) abuts against the stop portions, the ceiling (2) does not cover the main valve.

2. The reversible rainproof canopy for protecting nuclear power equipment according to claim 1 is characterized in that: The leg (1) comprises the foot (11), two support rods (12) respectively connected vertically to the foot (11), and a reinforcing rod (14) connected between the two support rods (12); the upper end of each support rod (12) has a connecting portion; the four side walls of the support rod (12) are respectively connected to the foot (11) via a reinforcing sheet (13).

3. The reversible rainproof canopy for protecting nuclear power equipment according to claim 2 is characterized in that: The stop portion is arranged at the upper end of the support rod (12), and comprises a stop plate (1221) and a support plate (1222), wherein the stop plate (1221) is parallel to the horizontal plane and vertically connected to the side wall of the support rod (12) facing away from the main valve, and the support plate (1222) is parallel to the vertical plane and vertically connected to the lower side of the stop plate (1221) and the side wall of the support rod (12) facing away from the main valve, respectively.

4. The reversible rainproof canopy for protecting nuclear power equipment according to claim 1 is characterized in that: The legs (1) and the frame are made of aluminum alloy profiles; the rain shield is made of corrugated board, double-sided rubber-lined oil-proof and fire-proof canvas or carbon fiber board.

5. The reversible rainproof canopy for protecting nuclear power equipment according to claim 1 is characterized in that: The shielding portion comprises a main frame; the main frame comprises a first longitudinal main beam (2131a) and a second longitudinal main beam (2131b) which are parallel, spaced and aligned, a first transverse main beam (2132a), a second transverse main beam (2132b) and a third transverse main beam (2132c) which are respectively and perpendicularly connected to the first longitudinal main beam (2131a) and the second longitudinal main beam (2131b) at two ends, a first reinforcing beam (2133a) which is respectively and perpendicularly connected to the first transverse main beam (2132a) and the second transverse main beam (2132b) at two ends, and a second reinforcing beam (2133b) which is respectively and perpendicularly connected to the second transverse main beam (2132b) and the third transverse main beam (2132c) at two ends; the second transverse main beam (2132b) is located at the first Between the transverse main beam (2132a) and the third transverse main beam (2132c), the first transverse main beam (2132a), the second transverse main beam (2132b) and the third transverse main beam (2132c) are arranged at equal intervals; the distance between the two first reinforcing beams (2133a), the distance between the first longitudinal main beam (2131a) and the adjacent first reinforcing beam (2133a), and the distance between the second longitudinal main beam (2131b) and the adjacent first reinforcing beam (2133a) are equal; the two second reinforcing beams (2133b) are respectively aligned one by one with the two first reinforcing beams (2133a); and the two second connecting rods (212) are respectively connected vertically to the lower side of the second longitudinal main beam (2131b).

6. The reversible rainproof canopy for protecting nuclear power equipment according to claim 5 is characterized in that: The lower side of the second longitudinal main beam (2131b) has two fixing parts, and the two second connecting rods (212) are respectively connected to the two fixing parts; the fixing part includes two parallel and spaced fixing plates (2134) respectively connected to the lower side of the second longitudinal main beam (2131b), the second connecting rod (212) includes a column (2121) and a bottom plate (2122), the upper end of the column (2121) is inserted between the two fixing plates (2134) of the corresponding fixing part and is connected to the two fixing plates (2134) by upper and lower bolts, the lower end of the column (2121) is vertically connected to the bottom plate (2122), and the bottom plate (2122) is used to be connected to the guardrail by bolts.

7. The reversible rainproof canopy for protecting nuclear power equipment according to claim 5 is characterized in that: The shielding portion also includes a sub-frame connected to the main frame; the sub-frame includes a first vertical rod (2135a), a second vertical rod (2135b) and a third vertical rod (2135c) respectively connected vertically to the lower side of the first longitudinal main beam (2131a), a longitudinal rod (2136) vertically connected to the first vertical rod (2135a), the second vertical rod (2135b) and the third vertical rod (2135c), a first oblique rod (2137a) connected at one end to the first transverse main beam (2132a) and at the other end to the longitudinal rod (2136), and a first oblique rod (2137a) connected at one end to the third transverse main beam (2132c) and at the other end to the longitudinal rod (2136). ) is connected to a second oblique rod (2137b) of the longitudinal rod (2136); the first vertical rod (2135a), the second vertical rod (2135b) and the third vertical rod (2135c) are respectively aligned with the first transverse main beam (2132a), the second transverse main beam (2132b) and the third transverse main beam (2132c); the first oblique rod (2137a) is parallel to the second oblique rod (2137b); the upper ends of the two first connecting rods (211) are respectively vertically connected to the lower side of the longitudinal rod (2136), and the interval between the two first connecting rods (211) is smaller than the distance between the first vertical rod (2135a) and the third vertical rod (2135c).

8. The reversible rainproof canopy for protecting nuclear power equipment according to claim 7 is characterized in that: The included angle between the first oblique rod (2137a) and the first connecting rod (211) is between 104° and 124°.

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