Plate type fuel assembly welding method

Abstract

The invention discloses a plate type fuel assembly welding method, relates to the technical field of welding methods, and aims to solve the problem that an existing plate type fuel assembly welding method cannot guarantee the symmetry degree. The method comprises the following steps: step 1, assembling a fuel assembly, carrying out size detection on the assembled fuel assembly, determining a spot welding sequence according to a detection result, and carrying out spot welding; 2, after the fuel assembly subjected to spot welding is fully cooled, size detection is conducted again, if the requirement is met, the next step is conducted, and if the requirement is not met, the first step and the second step are repeated till the requirement is met; thirdly, according to the size detection result meeting the requirement in the second step, the welding sequence of girth welding is judged, girth welding is carried out, size detection is carried out after the fuel assembly is cooled, if the requirement is met, welding is completed, and if the requirement is not met, the next step is carried out; and 4, according to the detection result which does not meet the requirement after girth welding, the hot straightening sequence is judged, and hot straightening is conducted till the degree of symmetry is close to zero.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of welding methods, and particularly relates to a plate type fuel assembly welding method. BACKGROUND

[0002] A traditional fuel assembly tube seat and side plate are combined by a screw assembly method, which is simple to operate, but the fuel assembly is in the reactor for a long time, and problems such as screw loosening, contact point corrosion and wear caused by the reactor environment exist, so a method of integrating the tube seat and the side plate of the plate type fuel assembly by welding is proposed to solve the above problems.

[0003] However, in the welding process of the plate type fuel assembly tube seat and the side plate, the aluminum material will deform greatly when heated, resulting in size deviation of the tube seat and the side plate after welding, especially the symmetry. These size deviations will affect the assembly and use of the fuel assembly in the reactor, and may even cause accidents. There is currently no solution to this problem. SUMMARY

[0004] The application aims to provide a plate type fuel assembly welding method to solve the problem that the existing plate type fuel assembly welding method cannot guarantee the symmetry.

[0005] The technical scheme adopted by the application to solve the technical problem is: a plate type fuel assembly welding method, wherein the method comprises:

[0006] Step 1: Assemble the assembly side plate and the tube seat, and detect the size of the assembled fuel assembly, and determine the spot welding sequence according to the detection result and perform spot welding according to the spot welding sequence. The determination basis of the spot welding sequence is: first, weld the symmetric position of the detected oversized position, and then complete the welding of the subsequent positions in sequence;

[0007] Step 2: After the fuel assembly is fully cooled after spot welding, size detection is performed again. If the symmetry result value detected by size detection is ≤0.4mm, the next step is performed. If the symmetry result value detected is >0.4mm, the spot welding sequence is reconfirmed according to the determination method of the spot welding sequence, and spot welding is performed again until the symmetry detection result is ≤0.4mm;

[0008] Step 3: According to the size detection result meeting the symmetry requirement in Step 2, the welding sequence of the girth welding is determined. The determination basis of the girth welding sequence is: first, weld the symmetric position on the side with the detected oversize, and then complete the welding of the subsequent positions in sequence, and perform girth welding according to the girth welding sequence. After the fuel assembly is fully cooled after girth welding, size detection is performed again. If the detection result shows that the symmetry is ≤0.2mm, the welding is completed. If the size detection result does not meet the requirement, the next step is performed.

[0009] Fourth step: judging the sequence of hot straightening according to the size detection results of the fuel assembly after the ring welding, the sequence of hot straightening is determined according to the following principle: first, the symmetric position of the detected larger side is straightened, then the hot straightening of the subsequent position is completed, and then the hot straightening is performed according to the determined sequence, after the fuel assembly is fully cooled, the size detection is performed, if the detection result does not meet the requirements, the second hot straightening is performed according to the above method.

[0010] The above-mentioned plate type fuel assembly welding method, wherein the size detection of the welding method adopts three-coordinate size detection method.

[0011] The above-mentioned plate type fuel assembly welding method, wherein the confirmation of the welding sequence in step one is: confirming the symmetry degree value of the fuel assembly in each direction through size detection, and dividing the detected symmetry degree value into three categories of unsatisfactory upper / lower symmetry degree, unsatisfactory left / right symmetry degree, and unsatisfactory symmetry degree in each direction,

[0012] When the upper / lower symmetry degree value is ≥0.4mm, and unsatisfactory:

[0013] When the upper part of the fuel assembly is larger, and the left / right symmetry degree value shows that the left side is larger than the right side, the determined welding sequence is in turn: welding point six, welding point three, welding point five, welding point two, welding point four, and welding point one;

[0014] When the upper part of the fuel assembly is larger, and the left / right symmetry degree value shows that the right side is larger than the left side, the determined welding sequence is in turn: welding point three, welding point six, welding point two, welding point five, welding point one, and welding point four;

[0015] When the lower part of the fuel assembly is larger, and the left / right symmetry degree value shows that the left side is larger than the right side, the determined welding sequence is in turn: welding point four, welding point one, welding point five, welding point two, welding point six, and welding point three;

[0016] When the lower part of the fuel assembly is larger, and the left / right symmetry degree value shows that the right side is larger than the left side, the determined welding sequence is in turn: welding point one, welding point four, welding point two, welding point five, welding point three, and welding point six;

[0017] When the left / right symmetry degree value is ≥0.4mm, and unsatisfactory:

[0018] When the left side of the fuel assembly is larger, and the upper / lower symmetry degree value shows that the upper side is larger than the lower side, the determined welding sequence is in turn: welding point five, welding point two, welding point six, welding point three, welding point four, and welding point one;

[0019] When the left side of the fuel assembly is large, and the up-and-down symmetry value shows that the lower side is larger than the upper side, the determined welding sequence is in turn: welding point five, welding point two, welding point four, welding point one, welding point six, welding point three;

[0020] When the right side of the fuel assembly is large, and the up-and-down symmetry value shows that the upper side is larger than the lower side, the determined welding sequence is in turn: welding point two, welding point five, welding point three, welding point six, welding point one, welding point four;

[0021] When the right side of the fuel assembly is large, and the up-and-down symmetry value shows that the lower side is larger than the upper side, the determined welding sequence is in turn: welding point two, welding point five, welding point one, welding point four, welding point three, welding point six;

[0022] When the up-and-down / left-and-right symmetry value is all ≥0.4 mm, when the requirement is not met:

[0023] When the upper part and the left side of the fuel assembly are both large, and the symmetry value shows that the large degree of the upper part is larger than that of the left side, the determined welding sequence is in turn: welding point six, welding point one, welding point five, welding point two, welding point three, welding point four;

[0024] When the upper part and the left side of the fuel assembly are both large, and the symmetry value shows that the large degree of the left side is larger than that of the upper part, the determined welding sequence is in turn: welding point five, welding point two, welding point six, welding point one, welding point four, welding point three;

[0025] When the upper part and the right side of the fuel assembly are both large, and the symmetry value shows that the large degree of the upper part is larger than that of the right side, the determined welding sequence is in turn: welding point three, welding point four, welding point two, welding point five, welding point six, welding point one;

[0026] When the upper part and the right side of the fuel assembly are both large, and the symmetry value shows that the large degree of the right side is larger than that of the upper part, the determined welding sequence is in turn: welding point two, welding point five, welding point three, welding point four, welding point one, welding point six;

[0027] When the lower part and the left side of the fuel assembly are both large, and the symmetry value shows that the large degree of the lower part is larger than that of the left side, the determined welding sequence is in turn: welding point four, welding point three, welding point five, welding point two, welding point one, welding point six;

[0028] When the lower part and the left side of the fuel assembly are both large, and the symmetry value shows that the large degree of the left side is larger than that of the lower part, the determined welding sequence is in turn: welding point five, welding point two, welding point four, welding point three, welding point six, welding point one;

[0029] When the lower part and the right side of the fuel assembly are both large, and the symmetry value shows that the large degree of the lower part is greater than that of the right side, the determined welding sequence is in turn: welding point one, welding point six, welding point two, welding point five, welding point four and welding point three.

[0030] When the lower part and the right side of the fuel assembly are both large, and the symmetry value shows that the large degree of the right side is greater than that of the lower part, the determined welding sequence is in turn: welding point two, welding point five, welding point one, welding point six, welding point three and welding point four.

[0031] The above-mentioned plate type fuel assembly welding method, wherein the confirmation of the welding sequence in step three is:

[0032] When the three-coordinate size detection shows that the upper part and the left side of the fuel assembly are large,

[0033] and the symmetry value shows that the large degree of the upper part is greater than that of the left side, the determined welding sequence is in turn: welding point five to welding point six, welding point two to welding point one, welding point two to welding point three and welding point five to welding point four;

[0034] and the symmetry value shows that the large degree of the left side is greater than that of the upper part, the determined welding sequence is in turn: welding point five to welding point six, welding point two to welding point one, welding point five to welding point four and welding point two to welding point three.

[0035] When the three-coordinate size detection shows that the upper part and the right side of the fuel assembly are large,

[0036] and the symmetry value shows that the large degree of the upper part is greater than that of the right side, the determined welding sequence is in turn: welding point two to welding point three, welding point five to welding point four, welding point five to welding point six and welding point two to welding point one.

[0037] and the symmetry value shows that the large degree of the right side is greater than that of the upper part, the determined welding sequence is in turn: welding point two to welding point three, welding point five to welding point four, welding point two to welding point one and welding point five to welding point six.

[0038] When the three-coordinate size detection shows that the lower part and the left side of the fuel assembly are large,

[0039] and the symmetry value shows that the large degree of the lower part is greater than that of the left side, the determined welding sequence is in turn: welding point five to welding point four, welding point two to welding point three, welding point two to welding point one and welding point five to welding point six.

[0040] When the left side of the symmetry value is larger than the lower side, the welding sequence is determined as follows: welding point five to welding point four, welding point two to welding point three, welding point five to welding point six, and welding point two to welding point one.

[0041] When the three-coordinate size detection shows that the lower side and the right side of the fuel assembly are larger,

[0042] When the lower side of the symmetry value is larger than the right side, the welding sequence is determined as follows: welding point two to welding point one, welding point five to welding point six, welding point five to welding point four, and welding point two to welding point three.

[0043] When the right side of the symmetry value is larger than the lower side, the welding sequence is determined as follows: welding point two to welding point one, welding point five to welding point six, welding point two to welding point three, and welding point five to welding point four.

[0044] The above-mentioned plate-type fuel assembly welding method, wherein the hot straightening position in step four is determined as follows:

[0045] When the three-coordinate size detection of the fuel assembly shows that the symmetry value in the up / down direction is greater than 0.2 mm, and the larger position is in the upper side, the hot straightening is performed on welding point three and welding point six; when the larger position is in the lower side, the hot straightening is performed on welding point one and welding point four.

[0046] When the three-coordinate size detection of the fuel assembly shows that the symmetry value in the left / right direction is greater than 0.2 mm, and the larger position is in the left side, the hot straightening is performed on welding point five; when the larger position is in the right side, the hot straightening is performed on welding point two.

[0047] When the three-coordinate size detection of the fuel assembly shows that the symmetry value in the up / down and left / right directions is greater than 0.2 mm, and the larger position is in the upper side and the left side, and the symmetry value in the upper side is larger than that in the left side, the hot straightening is performed on welding point six to welding point five. When the larger position is in the upper side and the left side, and the symmetry value in the left side is larger than that in the upper side, the hot straightening is performed on welding point five to welding point six.

[0048] When the larger position is in the upper side and the right side, and the symmetry value in the upper side is larger than that in the right side, the hot straightening is performed on welding point three to welding point two. When the larger position is in the upper side and the right side, and the symmetry value in the right side is larger than that in the upper side, the hot straightening is performed on welding point two to welding point three.

[0049] When the overlarge position is located at the lower part and the left side, and the numerical value shows that the overlarge degree of the lower part is greater than that of the left side, heat straightening is performed on the welding points four to five. When the overlarge position is located at the upper part and the left side, and the numerical value shows that the overlarge degree of the left side is greater than that of the lower part, heat straightening is performed on the welding points five to four.

[0050] When the overlarge position is located at the lower part and the right side, and the numerical value shows that the overlarge degree of the lower part is greater than that of the right side, heat straightening is performed on the welding points one to two. When the overlarge position is located at the upper part and the right side, and the numerical value shows that the overlarge degree of the right side is greater than that of the lower part, heat straightening is performed on the welding points two to one.

[0051] Compared with the prior art, the plate type fuel assembly welding method provided by the present application has the beneficial effects that: on the one hand, the symmetry degree of the fuel assembly is corrected through three-coordinate size detection and the method of split welding; on the other hand, a mature fuel assembly symmetry degree judgment system is developed, and different welding operations can be taken for various situations. BRIEF DESCRIPTION OF DRAWINGS

[0052] Fig. 1 Fig. 1 shows a plan view of a plate type fuel assembly welding method according to the present application;

[0053] Fig. 2 Fig. 1 shows a plan view of a plate type fuel assembly welding method according to the present application;

[0054] Fig. 3 Fig. 1 shows a plan view of a plate type fuel assembly welding method according to the present application;

[0055] BRIEF DESCRIPTION OF DRAWINGS 1. welding point one; 2. welding point two; 3. welding point three; 4. welding point four; 5. welding point five; 6. welding point six; 7. weld; 8. assembly side plate; 9. tube seat. DETAILED DESCRIPTION

[0056] In order to solve the problem that the existing plate type fuel assembly welding method cannot guarantee the symmetry degree, the present application provides a plate type fuel assembly welding method. The plate type fuel assembly to be welded is as shown in Figs. 1-3 Fig. 1, which comprises: an assembly side plate 8 and a tube seat 9, after the two are assembled, three-coordinate size detection is performed, and the weld 7 is welded according to the size detection result. Each welding point position of the weld of the assembled fuel plate type assembly is defined, and the left view of the fuel assembly is as shown in Fig. 3The upper left corner of the fuel assembly is defined as welding point one 1, the left side is defined as welding point two 2, the lower left corner is defined as welding point three 3, the upper right corner is defined as welding point four 4, the right side is defined as welding point five 5, and the lower right corner is defined as welding point six 6.

[0057] The welding sequence is determined because the welded part will shrink to a certain extent when the aluminum part is welded, and the welding sequence affects the shrinkage degree of the other side. Therefore, the same parameters will cause the shrinkage degree of one side to be higher. Therefore, the symmetry of the welded assembly can be affected by changing the welding sequence.

[0058] The plate type fuel assembly welding method comprises the following steps:

[0059] Step 1: Perform three-coordinate dimensional detection on the assembled fuel assembly, determine the spot welding sequence according to the dimensional detection results, and then perform spot welding operation according to the determined spot welding sequence.

[0060] Step 2: After the spot welding operation is completed, perform three-coordinate dimensional detection after the fuel assembly is fully cooled. If the detected symmetry result is ≤0.4mm, proceed to the next step. If the detected symmetry result is ≥0.4mm, reconfirm the spot welding sequence according to the spot welding sequence determination method, perform spot welding again until the symmetry detection result is ≤0.4mm, and then proceed to the next step.

[0061] Step 3: According to the three-coordinate dimensional detection results that meet the symmetry requirements in Step 2, determine the welding sequence of the girth welding, and perform girth welding according to the sequence. After the fuel assembly is fully cooled after girth welding, perform dimensional detection. If the three-coordinate dimensional detection result shows that the symmetry is ≤0.2mm, the welding is completed. If the dimensional detection result does not meet the requirements, proceed to the next step.

[0062] Step 4: According to the three-coordinate dimensional detection results that do not meet the requirements after girth welding of the fuel assembly, determine the sequence of heat straightening, and perform heat straightening according to the determined heat straightening sequence. After the fuel assembly is fully cooled, perform dimensional detection. If the detection result does not meet the requirements, perform the second heat straightening according to the above method.

[0063] Confirmation of spot welding sequence:

[0064] Confirm the symmetry value of the fuel assembly in each direction through three-coordinate dimensional detection. The detected symmetry value is divided into three categories: the upper / lower symmetry does not meet the requirements, the left / right symmetry does not meet the requirements, and the symmetry in each direction does not meet the requirements.

[0065] When the upper / lower symmetry value is ≥0.4mm and does not meet the requirements:

[0066] When the upper part of the fuel assembly is larger, and the left-right symmetry value shows that the left side is larger than the right side, the determined welding sequence is in turn: welding point six 6, welding point three 3, welding point five 5, welding point two 2, welding point four 4, and welding point one 1;

[0067] When the upper part of the fuel assembly is larger, and the left-right symmetry value shows that the right side is larger than the left side, the determined welding sequence is in turn: welding point three 3, welding point six 6, welding point two 2, welding point five 5, welding point one 1, and welding point four 4;

[0068] When the lower part of the fuel assembly is larger, and the left-right symmetry value shows that the left side is larger than the right side, the determined welding sequence is in turn: welding point four 4, welding point one 1, welding point five 5, welding point two 2, welding point six 6, and welding point three 3;

[0069] When the lower part of the fuel assembly is larger, and the left-right symmetry value shows that the right side is larger than the left side, the determined welding sequence is in turn: welding point one 1, welding point four 4, welding point two 2, welding point five 5, welding point three 3, and welding point six 6.

[0070] The left / right symmetry value is greater than or equal to 0.4 mm, and when the requirement is not met:

[0071] When the left side of the fuel assembly is larger, and the upper-lower symmetry value shows that the upper side is larger than the lower side, the determined welding sequence is in turn: welding point five 5, welding point two 2, welding point six 6, welding point three 3, welding point four 4, and welding point one 1;

[0072] When the left side of the fuel assembly is larger, and the upper-lower symmetry value shows that the lower side is larger than the upper side, the determined welding sequence is in turn: welding point five 5, welding point two 2, welding point four 4, welding point one 1, welding point six 6, and welding point three 3;

[0073] When the right side of the fuel assembly is larger, and the upper-lower symmetry value shows that the upper side is larger than the lower side, the determined welding sequence is in turn: welding point two 2, welding point five 5, welding point three 3, welding point six 6, welding point one 1, and welding point four 4;

[0074] When the right side of the fuel assembly is larger, and the upper-lower symmetry value shows that the lower side is larger than the upper side, the determined welding sequence is in turn: welding point two 2, welding point five 5, welding point one 1, welding point four 4, welding point three 3, and welding point six 6;

[0075] The upper-lower / left-right symmetry value is greater than or equal to 0.4 mm, and when the requirement is not met:

[0076] When the upper part and the left side of the fuel assembly are both large, and the symmetry value shows that the upper part is larger than the left side, the determined welding sequence is in turn: welding point six 6, welding point one 1, welding point five 5, welding point two 2, welding point three 3, and welding point four 4.

[0077] When the upper part and the left side of the fuel assembly are both large, and the symmetry value shows that the left side is larger than the upper part, the determined welding sequence is in turn: welding point five 5, welding point two 2, welding point six 6, welding point one 1, welding point four 4, and welding point three 3.

[0078] When the upper part and the right side of the fuel assembly are both large, and the symmetry value shows that the upper part is larger than the right side, the determined welding sequence is in turn: welding point three 3, welding point four 4, welding point two 2, welding point five 5, welding point six 6, and welding point one 1.

[0079] When the upper part and the right side of the fuel assembly are both large, and the symmetry value shows that the right side is larger than the upper part, the determined welding sequence is in turn: welding point two 2, welding point five 5, welding point one 1, welding point six 6, welding point three 3, and welding point four 4.

[0080] When the lower part and the left side of the fuel assembly are both large, and the symmetry value shows that the lower part is larger than the left side, the determined welding sequence is in turn: welding point four 4, welding point three 3, welding point five 5, welding point two 2, welding point one 1, and welding point six 6.

[0081] When the lower part and the left side of the fuel assembly are both large, and the symmetry value shows that the left side is larger than the lower part, the determined welding sequence is in turn: welding point five 5, welding point two 2, welding point four 4, welding point three 3, welding point six 6, and welding point one 1.

[0082] When the lower part and the right side of the fuel assembly are both large, and the symmetry value shows that the lower part is larger than the right side, the determined welding sequence is in turn: welding point one 1, welding point six 6, welding point two 2, welding point five 5, welding point four 4, and welding point three 3.

[0083] When the lower part and the right side of the fuel assembly are both large, and the symmetry value shows that the right side is larger than the lower part, the determined welding sequence is in turn: welding point two 2, welding point five 5, welding point one 1, welding point six 6, welding point three 3, and welding point four 4.

[0084] The direction of the girth welding is from the center to both sides, and the confirmation of the girth welding sequence is as follows:

[0085] When the three-coordinate size detection shows that the upper part and the left side of the fuel assembly are both large,

[0086] When the symmetry degree numerical value display shows that the upper portion is larger than the left side, the determined welding sequence is in turn: welding point five 5 to welding point six 6, welding point two 2 to welding point one 1, welding point two 2 to welding point three 3, and welding point five 5 to welding point four 4.

[0087] When the symmetry degree numerical value display shows that the left side is larger than the upper portion, the determined welding sequence is in turn: welding point five 5 to welding point six 6, welding point two 2 to welding point one 1, welding point five 5 to welding point four 4, and welding point two 2 to welding point three 3.

[0088] When the three-coordinate size detection shows that the upper portion and the right side of the fuel assembly are large,

[0089] When the symmetry degree numerical value display shows that the upper portion is larger than the right side, the determined welding sequence is in turn: welding point two 2 to welding point three 3, welding point five 5 to welding point four 4, welding point five 5 to welding point six 6, and welding point two 2 to welding point one 1.

[0090] When the symmetry degree numerical value display shows that the right side is larger than the upper portion, the determined welding sequence is in turn: welding point two 2 to welding point three 3, welding point five 5 to welding point four 4, welding point two 2 to welding point one 1, and welding point five 5 to welding point six 6.

[0091] When the three-coordinate size detection shows that the lower portion and the left side of the fuel assembly are large,

[0092] When the symmetry degree numerical value display shows that the lower portion is larger than the left side, the determined welding sequence is in turn: welding point five 5 to welding point four 4, welding point two 2 to welding point three 3, welding point two 2 to welding point one 1, and welding point five 5 to welding point six 6.

[0093] When the symmetry degree numerical value display shows that the left side is larger than the lower portion, the determined welding sequence is in turn: welding point five 5 to welding point four 4, welding point two 2 to welding point three 3, welding point five 5 to welding point six 6, and welding point two 2 to welding point one 1.

[0094] When the three-coordinate size detection shows that the lower portion and the right side of the fuel assembly are large,

[0095] When the symmetry degree numerical value display shows that the lower portion is larger than the right side, the determined welding sequence is in turn: welding point two 2 to welding point one 1, welding point five 5 to welding point six 6, welding point five 5 to welding point four 4, and welding point two 2 to welding point three 3.

[0096] When the value of the symmetry degree on the right side is larger than that on the lower side, the determined welding sequence is: welding point two 2 to welding point one 1, welding point five 5 to welding point six 6, welding point two 2 to welding point three 3, and welding point five 5 to welding point four 4.

[0097] Hot straightening position determination:

[0098] The result of the three-coordinate size detection of the fuel assembly shows that the value of the symmetry degree in the up / down direction is greater than 0.2 mm, when the overlarge position is located on the upper side, hot straightening is performed on welding point three 3 and welding point six 6; when the overlarge position is located on the lower side, hot straightening is performed on welding point one 1 and welding point four 4.

[0099] The result of the three-coordinate size detection of the fuel assembly shows that the value of the symmetry degree in the left / right direction is greater than 0.2 mm, when the overlarge position is located on the left side, hot straightening is performed on welding point five 5; when the overlarge position is located on the right side, hot straightening is performed on welding point two 2.

[0100] The result of the three-coordinate size detection of the fuel assembly shows that the value of the symmetry degree in the up / down and left / right directions is greater than 0.2 mm, when the overlarge position is located on the upper side and the left side, and the value on the upper side is larger than that on the left side, hot straightening is performed on welding point six 6 to welding point five 5; when the overlarge position is located on the upper side and the left side, and the value on the left side is larger than that on the upper side, hot straightening is performed on welding point five 5 to welding point six 6.

[0101] When the overlarge position is located on the upper side and the right side, and the value on the upper side is larger than that on the right side, hot straightening is performed on welding point three 3 to welding point two 2; when the overlarge position is located on the upper side and the right side, and the value on the right side is larger than that on the upper side, hot straightening is performed on welding point two 2 to welding point three 3.

[0102] When the overlarge position is located on the lower side and the left side, and the value on the lower side is larger than that on the left side, hot straightening is performed on welding point four 4 to welding point five 5; when the overlarge position is located on the upper side and the left side, and the value on the left side is larger than that on the lower side, hot straightening is performed on welding point five 5 to welding point four 4.

[0103] When the overlarge position is located on the lower side and the right side, and the value on the lower side is larger than that on the right side, hot straightening is performed on welding point one 1 to welding point two 2; when the overlarge position is located on the upper side and the right side, and the value on the right side is larger than that on the lower side, hot straightening is performed on welding point two 2 to welding point one 1.

[0104] It should be noted that the combination modes of the technical features in the embodiments of the present application are not limited to the combination modes described in the embodiments of the present application or the combination modes described in the specific embodiments, and all the technical features described in the present application can be freely combined or combined in any mode, unless contradictory.

[0105] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for welding plate-type fuel assemblies, characterized in that, The method includes: Step 1: Assemble the component side plate (8) and the tube base (9), perform dimensional inspection on the assembled fuel assembly, determine the spot welding sequence based on the inspection results, and perform spot welding according to the spot welding sequence. The basis for determining the spot welding sequence is: first weld the symmetrical position of the detected larger position, and then complete the welding of the subsequent points in sequence. Step 2: After the spot-welded fuel assembly has cooled sufficiently, perform a dimensional inspection again. If the symmetry result obtained from the dimensional inspection is ≤0.4mm, proceed to the next step. If the symmetry result obtained is >0.4mm, reconfirm the spot-welding sequence according to the method for determining the spot-welding sequence, and perform spot welding again until the symmetry result is ≤0.4mm. Step 3: Based on the dimensional inspection results from Step 2 that meet the symmetry requirements, determine the welding sequence for the circumferential welding. The circumferential welding sequence is determined as follows: first, weld the symmetrical position on the side that is found to be larger, then complete the welding of the subsequent positions in sequence, and perform circumferential welding according to the circumferential welding sequence. After the fuel assembly has been fully cooled after circumferential welding, perform dimensional inspection again. If the inspection result shows that the symmetry is ≤0.2mm, the welding is completed. If the dimensional inspection result does not meet the requirements, proceed to the next step. Step 4: Determine the heat straightening sequence based on the dimensional inspection results of the fuel assembly after ring welding that does not meet the requirements. The heat straightening sequence is determined as follows: first, perform heat straightening on the symmetrical position of the side that is found to be too large, and then complete the heat straightening of the subsequent positions in sequence. Perform heat straightening according to the determined heat straightening sequence. After the fuel assembly has cooled down sufficiently, perform dimensional inspection. If the inspection results do not meet the requirements, perform a second heat straightening according to the above method.

2. The method for welding plate-type fuel assemblies according to claim 1, characterized in that, The dimensional inspection of the welding method adopts the three-coordinate dimensional inspection method.

3. The method for welding plate-type fuel assemblies according to claim 1, characterized in that, The welding sequence in step one is confirmed as follows: The symmetry values ​​of the fuel assembly in each direction are confirmed through dimensional inspection. The detected symmetry values ​​are categorized into three types: top / bottom symmetry does not meet requirements, left / right symmetry does not meet requirements, and symmetry in all directions does not meet requirements. If the symmetry value of the upper / lower section is ≥0.4mm, and the requirement is not met: When the upper part of the fuel assembly is too large and the left and right symmetry values ​​show that the left side is greater than the right side, the welding sequence is determined as follows: welding point six (6), welding point three (3), welding point five (5), welding point two (2), welding point four (4), welding point one (1). When the upper part of the fuel assembly is too large and the symmetry value of the left and right sides shows that the right side is greater than the left side, the welding sequence is determined as follows: welding point three (3), welding point six (6), welding point two (2), welding point five (5), welding point one (1), welding point four (4). When the lower part of the fuel assembly is larger and the left and right symmetry values ​​show that the left side is larger than the right side, the welding sequence is determined as follows: welding point four (4), welding point one (1), welding point five (5), welding point two (2), welding point six (6), welding point three (3). When the lower part of the fuel assembly is too large and the symmetry value shows that the right side is greater than the left side, the welding sequence is determined as follows: welding point 1 (1), welding point 4 (4), welding point 2 (2), welding point 5 (5), welding point 3 (3), welding point 6 (6). If the left / right symmetry value is ≥0.4mm, and the requirement is not met: When the left side of the fuel assembly is larger and the symmetry value of the upper and lower parts shows that the upper part is larger than the lower part, the welding sequence is determined as follows: welding point five (5), welding point two (2), welding point six (6), welding point three (3), welding point four (4), welding point one (1). When the left side of the fuel assembly is larger and the symmetry value of the upper and lower parts shows that the lower part is larger than the upper part, the welding sequence is determined as follows: welding point five (5), welding point two (2), welding point four (4), welding point one (1), welding point six (6), welding point three (3). When the right side of the fuel assembly is larger and the symmetry value of the upper and lower parts shows that the upper part is larger than the lower part, the welding sequence is determined as follows: welding point 2 (2), welding point 5 (5), welding point 3 (3), welding point 6 (6), welding point 1 (1), welding point 4 (4). When the right side of the fuel assembly is larger and the symmetry value of the upper and lower parts shows that the lower part is larger than the upper part, the welding sequence is determined as follows: welding point 2 (2), welding point 5 (5), welding point 1 (1), welding point 4 (4), welding point 3 (3), welding point 6 (6). The vertical / horizontal symmetry values ​​are all ≥0.4mm. If the requirement is not met: When the upper and left sides of the fuel assembly are both too large, and the symmetry value shows that the upper part is larger than the left side, the welding sequence is determined as follows: welding point six (6), welding point one (1), welding point five (5), welding point two (2), welding point three (3), welding point four (4). When the upper and left sides of the fuel assembly are both too large, and the symmetry value shows that the left side is larger than the upper side, the welding sequence is determined as follows: welding point five (5), welding point two (2), welding point six (6), welding point one (1), welding point four (4), welding point three (3). When the upper and right sides of the fuel assembly are both too large, and the symmetry value shows that the upper part is larger than the right side, the welding sequence is determined as follows: welding point three (3), welding point four (4), welding point two (2), welding point five (5), welding point six (6), welding point one (1). When the upper and right sides of the fuel assembly are both too large, and the symmetry value shows that the right side is larger than the upper side, the welding sequence is determined as follows: welding point 2 (2), welding point 5 (5), welding point 3 (3), welding point 4 (4), welding point 1 (1), welding point 6 (6). When the lower part and left side of the fuel assembly are both too large, and the symmetry value shows that the lower part is larger than the left side, the welding sequence is determined as follows: welding point four (4), welding point three (3), welding point five (5), welding point two (2), welding point one (1), welding point six (6). When the lower and left sides of the fuel assembly are both too large, and the symmetry value shows that the left side is larger than the lower side, the welding sequence is determined as follows: welding point five (5), welding point two (2), welding point four (4), welding point three (3), welding point six (6), welding point one (1). When the lower and right sides of the fuel assembly are both too large, and the symmetry value shows that the lower part is larger than the right side, the welding sequence is determined as follows: welding point 1 (1), welding point 6 (6), welding point 2 (2), welding point 5 (5), welding point 4 (4), welding point 3 (3). When the lower and right sides of the fuel assembly are both larger than the upper part, and the symmetry value shows that the right side is larger than the lower part, the welding sequence is determined as follows: welding point 2 (2), welding point 5 (5), welding point 1 (1), welding point 6 (6), welding point 3 (3), welding point 4 (4).

4. The method for welding plate-type fuel assemblies according to claim 1, characterized in that, The sequence of ring welding in step three is indeed considered to be: When the coordinate measuring machine shows that the upper and left sides of the fuel assembly are too large, When the symmetry value shows that the upper part is larger than the left side, the welding sequence is determined as follows: welding point five (5) to welding point six (6), welding point two (2) to welding point one (1), welding point two (2) to welding point three (3), welding point five (5) to welding point four (4). When the symmetry value shows that the left side is larger than the top side, the welding sequence is determined as follows: welding point five (5) to welding point six (6), welding point two (2) to welding point one (1), welding point five (5) to welding point four (4), welding point two (2) to welding point three (3). When the coordinate measuring machine showed that the upper and right sides of the fuel assembly were too large, When the symmetry value shows that the upper part is larger than the right side, the welding sequence is determined as follows: welding point 2 (2) to welding point 3 (3), welding point 5 (5) to welding point 4 (4), welding point 5 (5) to welding point 6 (6), welding point 2 (2) to welding point 1 (1); When the symmetry value shows that the right side is larger than the top, the welding sequence is determined as follows: welding point 2 (2) to welding point 3 (3), welding point 5 (5) to welding point 4 (4), welding point 2 (2) to welding point 1 (1), welding point 5 (5) to welding point 6 (6). When the coordinate measuring machine shows that the lower and left sides of the fuel assembly are too large, When the symmetry value shows that the lower part is larger than the left side, the welding sequence is determined as follows: welding point five (5) to welding point four (4), welding point two (2) to welding point three (3), welding point two (2) to welding point one (1), welding point five (5) to welding point six (6). When the symmetry value shows that the left side is larger than the bottom side, the welding sequence is determined as follows: welding point five (5) to welding point four (4), welding point two (2) to welding point three (3), welding point five (5) to welding point six (6), welding point two (2) to welding point one (1); When the coordinate measuring machine showed that the lower and right sides of the fuel assembly were too large, When the symmetry value shows that the lower part is larger than the right side, the welding sequence is determined as follows: welding point 2 (2) to welding point 1 (1), welding point 5 (5) to welding point 6 (6), welding point 5 (5) to welding point 4 (4), welding point 2 (2) to welding point 3 (3). When the symmetry value shows that the right side is larger than the bottom side, the welding sequence is determined as follows: welding point 2 (2) to welding point 1 (1), welding point 5 (5) to welding point 6 (6), welding point 2 (2) to welding point 3 (3), welding point 5 (5) to welding point 4 (4).

5. The method for welding plate-type fuel assemblies according to claim 1, characterized in that, The location requiring heat straightening in step four is determined as follows: The results of the three-coordinate measurement of the fuel assembly showed that the symmetry value in the upper / lower direction was >0.2mm. When the larger position was located in the upper part, the welding point 3 (3) and welding point 6 (6) were heat-corrected; when the larger position was located in the lower part, the welding point 1 (1) and welding point 4 (4) were heat-corrected. The results of the three-coordinate measurement of the fuel assembly showed that the symmetry value in the left / right direction was >0.2mm. When the larger position was on the left, the welding point 5 (5) was heat-corrected; when the larger position was on the right, the welding point 2 (2) was heat-corrected. The results of the three-coordinate measurement of the fuel assembly showed that the symmetry values ​​in all directions (up / down and left / right) were >0.2mm. When the larger deviation was located at the top and left, and the values ​​showed that the larger deviation at the top was greater than that at the left, heat straightening was performed on welding points six (6) to five (5). When the larger deviation was located at the top and left, and the values ​​showed that the larger deviation at the left was greater than that at the top, heat straightening was performed on welding points five (5) to six (6). When the larger position is located at the top and right, and the numerical value shows that the larger position at the top is greater than the larger position at the right, heat straightening is performed on welding point three (3) to welding point two (2). When the larger position is located at the top and right, and the numerical value shows that the larger position at the right is greater than the larger position at the top, heat straightening is performed on welding point two (2) to welding point three (3). When the larger position is located at the bottom and left, and the numerical value shows that the larger position at the bottom is greater than that at the left, heat straightening is performed on welding points four (4) to five (5). When the larger position is located at the top and left, and the numerical value shows that the larger position at the left is greater than that at the bottom, heat straightening is performed on welding points five (5) to four (4). When the larger position is located at the bottom and right side, and the numerical value shows that the larger position at the bottom is greater than the larger position at the right side, heat straightening is performed on welding point 1 (1) to welding point 2 (2). When the larger position is located at the top and right side, and the numerical value shows that the larger position at the right side is greater than the larger position at the bottom, heat straightening is performed on welding point 2 (2) to welding point 1 (1).

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