An evaluation method for foreign matter abrasion on a secondary side of a steam generator

Abstract

The application discloses a kind of steam generator secondary side foreign matter abrasion evaluation methods, comprising the following steps: determining the basic information of the steam generator heat pipe to be evaluated: including heat pipe outer diameter Dt and heat pipe wall thickness W;Determine the basic information of the secondary side foreign matter to be evaluated: including the geometric structure of foreign matter, basic geometric dimension coefficient α, lateral geometric structure coefficient β1, axial geometric structure coefficient β2, the wear coefficient K between foreign matter and heat pipe, foreign matter mass m;Determine the fluid information of the steam generator position where the secondary side foreign matter to be evaluated is located: including flow coefficient γ;Determine the flow-induced vibration information of the steam generator position where the secondary side foreign matter to be evaluated is located heat pipe: including vibration frequency f and vibration amplitude d;Calculate critical wear time t.The steam generator secondary side foreign matter abrasion evaluation method of the application realizes the evaluation of the influence of different types of secondary side foreign matter on the service life of heat pipe, and the critical wear time can be quickly obtained, with fast evaluation speed and high precision.

Description

Technical Field

[0001] This invention relates to the field of fretting wear technology, and more particularly to a method for evaluating foreign matter wear on the secondary side of a steam generator. Background Technology

[0002] The steam generator is one of the most important main pieces of equipment in a nuclear power plant's nuclear island, serving as the heat exchange hub between the primary and secondary loops. Its structural integrity and flow heat transfer characteristics are crucial for the safe and economical operation of the nuclear power plant. Domestic and international operational experience shows that foreign matter problems on the secondary side of the steam generator are among its major defects. In some units, leaks in the heat transfer tubes due to foreign matter have led to shutdowns and reactor failures, posing a significant threat to the reliability of the steam generator and creating a major hidden danger to the safe and reliable operation of the nuclear power plant.

[0003] Currently, our understanding of the movement patterns of foreign objects and their potential impact on heat transfer tube defects and their evolution is insufficient. The mechanism of secondary-side foreign object wear on heat transfer tubes is unclear, and there is no unified understanding or criterion for assessing the wear risk of secondary-side foreign objects on heat transfer tubes. The material and structure of foreign objects and the randomness of secondary-side flow pulsation are also significant, and no systematic summary has been made. Therefore, there is currently no rapid, mature, and usable assessment method for secondary-side foreign object wear, making it impossible to accurately assess the hazards of secondary-side foreign objects in steam generators, which seriously affects the safe operation and low-cost maintenance of nuclear power plant steam generators.

[0004] The movement of foreign objects on the secondary side between heat transfer tubes involves multiple physical processes, including heat transfer, flow, friction, and impact. The size, shape, location, and fretting of these foreign objects exhibit significant randomness, making the problem extremely complex. Therefore, it is urgent to conduct research on the assessment of wear caused by secondary side foreign objects on heat transfer tubes, and to develop wear assessment methods. This will provide theoretical support for improving the procedures for handling secondary side foreign objects in steam generators, and is of great significance to the safe operation of steam generators. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for evaluating foreign matter wear on the secondary side of a steam generator.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for assessing foreign matter wear on the secondary side of a steam generator includes the following steps:

[0008] Determine the basic information of the heat transfer tubes of the steam generator to be evaluated, including the outer diameter D of the heat transfer tubes. t and heat transfer tube wall thickness W;

[0009] Determine the basic information of the foreign object to be evaluated on the secondary side: including the geometry of the foreign object, the basic geometric dimension coefficient α, the lateral geometric dimension coefficient β1, the axial geometric dimension coefficient β2, the wear coefficient K between the foreign object and the heat transfer tube, and the mass m of the foreign object;

[0010] Determine the fluid information of the location of the foreign object on the secondary side of the steam generator to be evaluated, including the fluid coefficient γ;

[0011] Determine the flow-induced vibration information of the heat transfer tube at the location of the secondary-side foreign object to be evaluated in the steam generator: including vibration frequency f and vibration amplitude d;

[0012] The critical wear time t is calculated using the following formula:

[0013] t = V c / [K×(β1×γ×α 2 / (f×m)+4×β2×γ 0.5 ×α×f×d)]

[0014] In the formula, V c β1 is the critical wear volume, K is the wear coefficient between the foreign object and the heat transfer tube, β2 is the lateral geometric structure coefficient of the foreign object, γ is the fluid coefficient, f is the vibration frequency, d is the vibration amplitude, α is the basic geometric size coefficient of the foreign object, and m is the mass of the foreign object.

[0015] According to some preferred embodiments of the invention, the critical wear volume V c It is calculated using the following formula:

[0016] V c =0.125×D t 2 ×D×[2×θ-sin(2×θ)]

[0017] In the formula, θ is the critical wear angle, and D t D is the outer diameter of the heat transfer tube, and D is the size of the foreign object.

[0018] According to some preferred embodiments of the present invention, the critical wear angle θ is calculated by the following formula:

[0019] θ = arccos(1 - 0.8 × W / D) t )

[0020] In the formula, W is the wall thickness of the heat transfer tube.

[0021] According to some preferred embodiments of the invention, the geometry of the foreign object includes a cylinder, a cuboid, and a sphere.

[0022] According to some preferred embodiments of the present invention, the size D of the foreign object is obtained by the following criteria: if the foreign object is a cylinder, D is the diameter of the foreign object's cross section; if the foreign object is a cuboid, D is the second longest side; if the foreign object is a sphere, D is the diameter of the foreign object.

[0023] According to some preferred embodiments of the present invention, the basic geometric dimension coefficient α of the foreign object is obtained by the following formula:

[0024] α = D × L, where the foreign object is a cylinder, D is the diameter of the foreign object's cross-section, and L is the length of the foreign object;

[0025] α = D × L, where the foreign object is a cuboid, D is the second longest side, and L is the longest side;

[0026] α = D × D, where the foreign object is a sphere and D is the diameter of the foreign object.

[0027] According to some preferred embodiments of the present invention, the lateral geometrical coefficient β1 of the foreign object is obtained by the following criterion:

[0028] The foreign object is cylindrical, and 0.012≤β1≤0.013;

[0029] The foreign object is a cuboid, with 0.035 ≤ β1 ≤ 0.036;

[0030] The foreign object is a sphere, and 0.410≤β1≤0.415.

[0031] According to some preferred embodiments of the present invention, the axial geometric coefficient β2 of the foreign object is obtained by the following criteria:

[0032] The foreign object is cylindrical, with 1.577 ≤ β2 ≤ 1.743;

[0033] The foreign object is a cuboid, with 0.870 ≤ β² ≤ 0.890;

[0034] The foreign object is a sphere, 18.40≤β2≤18.50.

[0035] According to some preferred embodiments of the present invention, the fluid coefficient γ is calculated by the following formula:

[0036] γ=ρ 2 v 4

[0037] In the formula, ρ is the fluid density and v is the transverse fluid velocity.

[0038] Due to the adoption of the above technical solutions, the advantages of the present invention compared with the prior art are as follows: the evaluation method for foreign matter wear on the secondary side of the steam generator of the present invention realizes the rapid evaluation of the impact of different types of secondary side foreign matter on the service life of heat transfer tubes, can quickly obtain the critical wear time, and has a fast evaluation speed and high evaluation accuracy. Detailed Implementation

[0039] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0040] The method for assessing foreign matter wear on the secondary side of a steam generator in this embodiment includes the following steps:

[0041] Step (1): Determine the basic information of the heat transfer tubes of the steam generator to be evaluated.

[0042] Basic information about heat transfer tubes includes the outer diameter D of the heat transfer tube. t And the wall thickness W of the heat transfer tube.

[0043] Step (2): Determine the basic information of the secondary foreign body to be evaluated.

[0044] The basic information of the foreign object includes its geometry, basic geometric dimension coefficient α, lateral geometric dimension coefficient β1, axial geometric dimension coefficient β2, wear coefficient K between the foreign object and the heat transfer tube, and mass m of the foreign object.

[0045] In this method, the geometry of the foreign object is only applicable to three types of foreign objects: cylinders, cuboids, and spheres. Based on the different geometries of the foreign object, the corresponding basic geometric dimension coefficient α, lateral geometric structure coefficient β1, and axial geometric structure coefficient β2 are obtained according to the following criteria. Specifically:

[0046] The basic geometric dimension coefficient α of the foreign object is calculated using the following formula:

[0047] (A) α = D × L, the foreign object is a cylinder, D is the diameter of the foreign object's cross section, and L is the length of the foreign object;

[0048] (B) α = D × L, the foreign object is a cuboid, D is the second longest side, and L is the longest side;

[0049] (C) α = D × D, the foreign object is a sphere, and D is the diameter of the foreign object.

[0050] The lateral geometric structure coefficient β1 of the foreign object is obtained through the following empirical fitting.

[0051] (A) The foreign object is cylindrical, 0.012≤β1≤0.013;

[0052] (B) The foreign body is a cuboid, 0.035≤β1≤0.036;

[0053] (C) The foreign body is a sphere, 0.410≤β1≤0.415.

[0054] The axial geometric structure coefficient β2 of the foreign object is obtained through the following empirical fitting.

[0055] (A) The foreign object is cylindrical, 1.577≤β2≤1.743;

[0056] (B) The foreign body is a cuboid, 0.870≤β2≤0.890;

[0057] (C) The foreign body is a sphere, 18.40≤β2≤18.50.

[0058] Step (3): Determine the fluid information of the location of the foreign object on the secondary side to be evaluated in the steam generator.

[0059] Fluid information includes the fluid coefficient γ, which is calculated using the following formula:

[0060] γ=ρ 2 v 4

[0061] In the formula, ρ is the fluid density and v is the transverse fluid velocity.

[0062] Step (4): Determine the flow-induced vibration information of the heat transfer tube at the location of the foreign object on the secondary side of the steam generator to be evaluated.

[0063] Flow-induced vibration information includes vibration frequency f and vibration amplitude d.

[0064] Step (5): Calculate the critical wear volume V c

[0065] Critical wear volume V c It is calculated using the following formula:

[0066] V c =0.125×D t 2 ×D×[2×θ-sin(2×θ)]

[0067] In the formula, θ is the critical wear angle, which is calculated using the following formula:

[0068] θ = arccos(1 - 0.8 × W / D) t )

[0069] Step (6): Calculate the critical wear time t

[0070] The critical wear time is calculated using the following formula:

[0071] t = V c / [K×(β1×γ×α 2 / (f×m)+4×β2×γ 0.5 ×α×f×d)]

[0072] The critical wear time is compared with the acceptable assessment and treatment cycle of the nuclear power plant. If the critical wear time is greater than the assessment and treatment cycle, no further measures are required; if the critical wear time is less than the assessment and treatment cycle, the foreign object needs to be removed.

[0073] Example 1

[0074] This invention relates to a method for assessing foreign object wear on the secondary side of a steam generator. This method allows for the analysis of the impact of foreign object wear on heat transfer tubes. The specific steps for implementing this method include the following:

[0075] (1) Determine the basic information of the heat transfer tubes of the steam generator to be evaluated: including the outer diameter D of the heat transfer tubes. t =19.05mm, heat transfer tube wall thickness W=1.09mm;

[0076] (2) Determine the basic information of the secondary foreign body to be evaluated: including the foreign body's geometric structure as a cylinder, and the basic geometric dimension coefficient α = D × L = 1.6 × 76 = 121.6 mm. 2 The transverse geometric coefficient β1 = 0.0126, the axial geometric coefficient β2 = 1.660, and the wear coefficient for foreign objects and heat transfer tubes K = 1.27 × 10⁻⁶. -14 Pa -1 The mass of the foreign object is m = 1.2g;

[0077] (3) Determine the fluid information of the location of the foreign object on the secondary side of the steam generator to be evaluated: including the fluid coefficient γ = ρ 2 v 4 =773.590 2 ×1.149 2 =790063(kg / (m) 2 s)) 2 ;

[0078] (4) Determine the flow-induced vibration information of the heat transfer tube at the location of the foreign object on the secondary side of the steam generator to be evaluated: including the vibration frequency f = 78 Hz and the vibration amplitude d = 0.018 mm;

[0079] (5) Calculate the critical wear volume V c =0.125×D t 2 ×D×[2×θ-sin(2×θ)]=0.125×(19.05×10 -3 ) 2 ×1.6×10 -3×[2×0.3037-sin(2×0.3037)]=2.6621×10 -9 m 3 ;

[0080] (6) Calculate the critical wear time t = V c / [K×(β1×γ×α 2 / (f×m)+4×β2×γ 0.5 [×α×f×d)]=2.6621×10 -9 / [1.27×10 -14 ×(0.0126×790063×(121.6×10 -6 ) 2 / (78×1.2×10 -3 )+1.660×790063 0.5 ×121.6×10 -6 ×78×0.018×10 -3 )] = 8.861 × 107 seconds = 2.81 years.

[0081] Example 2

[0082] This invention relates to a method for assessing foreign object wear on the secondary side of a steam generator. This method allows for the analysis of the impact of foreign object wear on heat transfer tubes. The specific steps for implementing this method include the following:

[0083] (1) Determine the basic information of the heat transfer tubes of the steam generator to be evaluated: including the outer diameter D of the heat transfer tubes. t =19.05mm, heat transfer tube wall thickness W=1.09mm;

[0084] (2) Determine the basic information of the secondary foreign body to be evaluated: including the geometric structure of the foreign body as a cuboid, and the basic geometric dimension coefficient α=D×L=6.4×25=160mm. 2 The transverse geometric coefficient β1 = 0.0357, the axial geometric coefficient β2 = 0.880, and the wear coefficient of foreign matter and heat transfer tubes K = 1.27 × 10⁻⁶. -14 Pa -1 The mass of the foreign object is m = 1.3g;

[0085] (3) Determine the fluid information of the location of the foreign object on the secondary side of the steam generator to be evaluated: including the fluid coefficient γ = ρ 2 v 4 =773.590 2 ×1.149 2 =790063(kg / (m) 2 s)) 2 ;

[0086] (4) Determine the flow-induced vibration information of the heat transfer tube at the location of the foreign object on the secondary side of the steam generator to be evaluated: including the vibration frequency f = 78 Hz and the vibration amplitude d = 0.018 mm;

[0087] (5) Calculate the critical wear volume V c =0.125×D t 2 ×D×[2×θ-sin(2×θ)]=0.125×(19.05×10 -3 ) 2 ×6.4×10 -3 ×[2×0.3037-sin(2×0.3037)]=1.0649×10 -8 m 3 ;

[0088] (6) Calculate the critical wear time t = V c / [K×(β1×γ×α 2 / (f×m)+4×β2×γ 0.5 [×α×f×d)]=1.0649×10 -8 / [1.27×10 -14 ×(0.0357×790063×(121.6×10 -6 ) 2 / (78×1.2×10 -3 )+0.880×790063 0.5 ×121.6×10 -6 ×78×0.018×10 -3 )]=8.7398×10 7 Second = 2.77 years.

[0089] Example 3

[0090] This invention relates to a method for assessing foreign object wear on the secondary side of a steam generator. This method allows for the analysis of the impact of foreign object wear on heat transfer tubes. The specific steps for implementing this method include the following:

[0091] (1) Determine the basic information of the heat transfer tubes of the steam generator to be evaluated: including the outer diameter D of the heat transfer tubes. t =19.05mm, heat transfer tube wall thickness W=1.09mm;

[0092] (2) Determine the basic information of the secondary foreign body to be evaluated: including the foreign body's geometry as a sphere, and the basic geometric dimension coefficient α = D × D = 12.5 × 12.5 = 156.25 mm. 2 The transverse geometric coefficient β1 = 0.413, the axial geometric coefficient β2 = 18.457, and the wear coefficient of foreign matter and heat transfer tubes K = 1.27 × 10⁻⁶.-14 Pa -1 The mass of the foreign object is m = 8g;

[0093] (3) Determine the fluid information of the location of the foreign object on the secondary side of the steam generator to be evaluated: including the fluid coefficient γ = ρ 2 v 4 =773.590 2 ×1.149 2 =790063(kg / (m) 2 s)) 2 ;

[0094] (4) Determine the flow-induced vibration information of the heat transfer tube at the location of the foreign object on the secondary side of the steam generator to be evaluated: including the vibration frequency f = 78 Hz and the vibration amplitude d = 0.018 mm;

[0095] (5) Calculate the critical wear volume V c =0.125×D t 2 ×D×[2×θ-sin(2×θ)]=0.125×(19.05×10 -3 ) 2 ×12.5×10 -3 ×[2×0.3037-sin(2×0.3037)]=2.0798×10 -8 m 3 ;

[0096] (6) Calculate the critical wear time t = V c / [K×(β1×γ×α 2 / (f×m)+4×β2×γ 0.5 [×α×f×d)]=2.0798×10 -8 / [1.27×10 -14 ×(0.0357×790063×(121.6×10 -6 ) 2 / (78×1.2×10 -3 )+0.880×790063 0.5 ×121.6×10 -6 ×78×0.018×10 -3 )]=9.7145×10 7 Second = 3.08 years.

[0097] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for assessing foreign matter wear on the secondary side of a steam generator, characterized in that, Includes the following steps: Determine the information of the heat transfer tubes of the steam generator to be evaluated, including the outer diameter of the heat transfer tubes. D t and heat transfer tube wall thickness W ; Determine information about the secondary side foreign body to be evaluated, including its geometry and basic geometric dimensions. α Lateral geometric structure coefficient β 1. Axial geometric coefficient β 2. Wear coefficient K between the foreign object and the heat transfer tube, and the mass of the foreign object. m ; Fluid information to determine the location of the foreign object on the secondary side of the steam generator to be evaluated, including fluid coefficients. γ ; Determine the flow-induced vibration information of the heat transfer tube at the location of the foreign object on the secondary side of the steam generator to be evaluated: including vibration frequency. f and vibration amplitude d ; The critical wear time is calculated using the following formula. t : t = V c / [K×( β 1× γ × α 2 / ( f × m)+ 4× β 2× γ 0.5 × α × f × d )] In the formula, V c Where K is the critical wear volume, and K is the wear coefficient between the foreign object and the heat transfer tube. β 1 represents the lateral geometric structure coefficient of the foreign object. β 2 represents the axial geometric structure coefficient of the foreign object. γ For fluid coefficient, f The vibration frequency, d The amplitude of vibration. α The basic geometric dimension coefficient of the foreign object. m For the mass of the foreign object; The critical wear volume V c It is calculated using the following formula: V c = 0.125× D t 2 ×D×[2×θ-sin(2×θ)] In the formula, θ is the critical wear angle. D t The outer diameter of the heat transfer tube. D The size of the foreign object; The critical wear angle θ is calculated using the following formula: θ = arccos(1-0.8× W / D t ) In the formula, W For the thickness of the heat transfer tube wall.

2. The evaluation method according to claim 1, characterized in that, The geometry of the foreign object includes cylinders, cuboids, and spheres.

3. The evaluation method according to claim 2, characterized in that, The size D of the foreign object is obtained according to the following criteria: if the foreign object is a cylinder, D is the diameter of the cross section of the foreign object; if the foreign object is a cuboid, D is the second longest side; if the foreign object is a sphere, D is the diameter of the foreign object.

4. The evaluation method according to claim 2, characterized in that, The basic geometric dimension coefficient of the foreign object α It can be obtained through the following formula: α = D × L The foreign object is cylindrical. D The diameter of the foreign object's cross-section. L The length of the foreign object; α = D × L The foreign object is a cuboid. D The second longest side, L The longer side; α = D × D The foreign object is a sphere. D The diameter of the foreign object.

5. The evaluation method according to claim 2, characterized in that, The lateral geometrical coefficient of the foreign object β 1 is obtained through the following criteria: The foreign object is cylindrical, 0.012 ≤ β 1 ≤ 0.013; The foreign object is a cuboid, 0.035 ≤ β 1 ≤ 0.036; The foreign object is a sphere, 0.410 ≤ β 1 ≤ 0.

415.

6. The evaluation method according to claim 2, characterized in that, The axial geometric coefficient of the foreign object β 2 is obtained through the following criteria: The foreign object is cylindrical, 1.577 ≤ β 2 ≤ 1.743; The foreign object is a cuboid, 0.870 ≤ β 2 ≤ 0.890; The foreign object is a sphere, 18.40 ≤ β 2 ≤ 18.

50.

7. The evaluation method according to claim 1, characterized in that, The fluid coefficient γ It is calculated using the following formula: c = ρ 2 v 4 In the formula, ρ For fluid density, v This represents the transverse fluid velocity.