CN-122007879-A - Method for thermally stretching main bolts of coolant shielding motor pump of passive advanced pressurized water reactor

CN122007879ACN 122007879 ACN122007879 ACN 122007879ACN-122007879-A

Abstract

The invention discloses a hot stretching method of a main pump bolt of a coolant shielding motor of a passive advanced pressurized water reactor, which is suitable for mounting and tightening a large-sized full-threaded bolt and a nut, can be mounted by utilizing the characteristic of thermal expansion and contraction, is suitable for equipment running at high temperature, can be used in a narrow space by reducing the space requirement of machinery required by the mounting equipment, divides the required elongation into two hot stretching and one-time balanced stretching, can eliminate the influence of the compressible quantity between a pump shell and the main pump by the first hot stretching, and performs grouping stretching on the bolt according to the stretching rule for the second time, and finally performs integral stretching on the bolt by the stretching rule, so that all the bolts are stretched in place, and the same stretching quantity can be obtained.

Inventors

HU FUWEI
ZHU XIAOQIANG
CHEN XIANG
CHEN JUNYANG
GAO HONGYE
ZHANG HUANWEN
Sheng Zhaoye
SHI HAOJIE
MA LI

Assignees

中国能源建设集团浙江火电建设有限公司

Dates

Publication Date: 20260512
Application Date: 20260402

Claims (10)

1. The method for hot stretching the main pump bolts of the coolant shielding motor of the passive advanced pressurized water reactor is characterized by comprising the following steps: s1, numbering all bolt holes on a pump shell and numbering all bolts to be installed; s2, grouping the numbered bolt holes, and grouping the numbered bolts; S3, setting a planned elongation, namely setting a planned elongation of B 1 , wherein B 1 is required to meet the requirement of the stretching amount A of a single bolt and the average value C of the stretching amounts of all bolts; s4, performing first hot stretching on the bolts according to groups; s5, performing secondary hot stretching on the bolts according to groups; and S6, carrying out heat balance stretching on the bolts which do not meet the planned elongation B 1 until all the bolts meet the planned elongation B 1 .
2. The method for hot stretching the main pump bolts of the coolant shielding motor of the passive advanced pressurized water reactor according to claim 1, wherein the pump shell is provided with 24 bolt holes, the number of the bolt holes is 1# -24#, and correspondingly, the number of the bolts is 24, and the number of the bolts is 1-24.
3. The passive advanced pressurized water reactor coolant shield motor main pump bolt heat drawing method of claim 2, wherein bolt holes numbered 1#, 4#, 7#, 10#, 13#, 16#, 19#, 22# are divided into a first set of bolt holes, 2#, 5#, 8#, 11#, 14#, 17#, 20#, 23# are divided into a second set of bolt holes, 3#,6#,9#,12#,15#,18#,21#,24# are divided into a third set of bolt holes, and corresponding 1,4,7,10,13,16, 19, 22 are divided into a first set of bolts, and 2, 5, 8, 11, 14, 17, 20, 23 are divided into a second set of bolts, and 3,6,9,12,15,18,21,24 are divided into a third set of bolts.
4. The passive advanced pressurized water reactor coolant shield motor main pump bolt hot stretching method as set forth in claim 3, wherein the specific steps of the first hot stretching in step S4 are as follows: S401, performing first hot stretching on a third group of bolts, loading the third group of bolts into the first group of bolt holes, pre-installing nuts on the third group of bolts, heating the third group of bolts by using a bolt heater, rotating the nuts E 1 after heating, measuring the third group of bolts by using a measuring instrument after cooling, and measuring that the elongation of the first hot stretching of the third group of bolts is B 2 ; S402, welding a first part of a C-shaped connecting surface of the pump shell and the main pump, which is not blocked by a bolt; S403, performing first hot stretching on the second group of bolts, loading the second group of bolts into the second group of bolt holes, pre-installing nuts on the second group of bolts, heating the second group of bolts by using a bolt heater, rotating the nuts E 2 after heating, measuring the second group of bolts by using a measuring instrument after cooling, and measuring that the elongation of the first hot stretching of the second group of bolts is B 3 ; S404, transposition hot stretching of a third group of bolts, namely detaching the third group of bolts, mounting the third group of bolts on the third group of bolt holes, pre-mounting nuts on the third group of bolts, heating the third group of bolts by using a bolt heater, rotating the nuts E 3 after heating, measuring the third group of bolts by using a measuring instrument after cooling, and measuring the elongation of the transposition hot stretching of the third group of bolts to be B 4 ; S405, welding a second part of the C-shaped connecting surface of the pump shell and the main pump, which is not blocked by the bolts; S406, performing first hot stretching on the first group of bolts, installing the first group of bolts into the first group of bolt holes, pre-installing nuts on the first group of bolts, heating the first group of bolts by using a bolt heater, rotating the nuts E 4 after heating, measuring the first group of bolts by using a measuring instrument after cooling, and measuring the elongation of the first group of bolts in the first hot stretching to be B 5 .
5. The passive advanced pressurized water reactor coolant shield motor main pump bolt hot stretching method as set forth in claim 4, wherein the specific steps of the second hot stretching in S5 are as follows: S501, measuring the elongation of the second group of bolts and the elongation of the third group of bolts, wherein a measuring instrument is used for measuring the elongation of the second group of bolts and the elongation of the third group of bolts, the elongation of the second group of bolts is measured to be B 6 , and the elongation of the third group of bolts is measured to be B 7 ; S502, performing second hot stretching on the second group of bolts, wherein the residual stretching amount of the second group of bolts is B 8 =B 1 -B 6 , obtaining a corresponding nut rotation angle E 5 according to a stretching rule, reheating the second group of bolts by using a bolt heater, and rotating the nuts of the second group of bolts E 5 ; s503, performing second hot stretching on the third group of bolts, measuring by using a measuring instrument after the second group of bolts are subjected to second hot stretching and cooling to obtain the elongation of the third group of bolts as B 9 , obtaining the residual elongation of the third group of bolts as B 10 =B 1 -B 9 , obtaining a corresponding nut rotation angle as E 6 according to a stretching rule, reheating the third group of bolts by using a bolt heater, and rotating the nuts of the third group of bolts as E 6 ; S504, performing second hot stretching on the first group of bolts, measuring by using a measuring instrument after the third group of bolts are subjected to second hot stretching and cooling to obtain the elongation of the first group of bolts as B 11 , obtaining the residual elongation of the first group of bolts as B 12 =B 1 -B 11 , obtaining the corresponding nut rotation angle as E 7 according to the stretching rule, reheating the first group of bolts by using a bolt heater, and rotating the nuts of the first group of bolts as E 7.
6. The passive advanced pressurized water reactor coolant shield motor main pump bolt hot drawing method of claim 5, wherein the specific steps in S6 are as follows: S601, measuring elongation again, measuring the elongation of each bolt by using a measuring instrument after the first bolt is subjected to hot stretching and cooling for the second time, wherein the elongation of the first bolt is B 13 , the elongation of the second bolt is B 14 , and the elongation of the third bolt is B 15 ; S602, comparing the elongation with the planned elongation, and comparing B 13 、B 14 、B 15 with B 1 to see whether the elongation meets the requirement of the planned elongation B 1 ; S603, performing heat balance stretching, namely performing heat balance stretching on bolts which do not meet the requirement of the planned elongation, calculating residual stretching amounts of all bolts which do not meet the requirement of the planned elongation B 1 , wherein the residual stretching amount of the first group of bolts is B 16 =B 1 -B 13 , the rotation angle of the corresponding nut is E 8 according to a stretching rule, the residual stretching amount of the second group of bolts is B 17 =B 1 -B 14 , the rotation angle of the corresponding nut is E 9 according to the stretching rule, the residual stretching amount of the third group of bolts is B 18 =B 1 -B 15 , and the rotation angle of the corresponding nut is E according to the stretching rule 10; S604, performing hot stretching and rotating a bolt which does not meet the planned elongation B 1 by a corresponding angle by using a bolt heater, re-measuring by using a measuring instrument after cooling, and performing hot balance stretching without time limitation until the elongation of all bolts reaches the planned elongation B 1 .
7. The passive advanced pressurized water reactor coolant shielding motor main pump bolt hot stretching method according to claim 1, wherein a bolt with consistent specification is placed in the equipment to be a check bolt before the first hot stretching installation of the bolt, the initial length of all bolts and the check bolt is measured once by using a measuring instrument, and when the bolt is hot stretched and waiting to be cooled, the check bolt is measured again by using the measuring instrument, and whether the measuring instrument is accurate is checked by comparing the two measured values.
8. The passive advanced pressurized water reactor coolant shield motor main pump bolt heat stretching method as set forth in claim 4, wherein all bolts need to be ensured to extend beyond the flange face of the pump casing by a length satisfying the extending amount D when all bolts are installed in the bolt holes in the first heat stretching.
9. The passive advanced pressurized water reactor coolant shield motor main pump bolt hot stretching method of claim 7, wherein the stretching rule is that the stretching amount of the bolts increases by Y for each rotation E of the nuts.
10. The passive advanced pressurized water reactor coolant shield motor main pump bolt hot drawing method of claim 1, wherein the measuring instrument is a flange bolt depth gauge.

Description

Method for thermally stretching main bolts of coolant shielding motor pump of passive advanced pressurized water reactor Technical Field The invention relates to the technical field of bolt hot stretching, in particular to a method for hot stretching a main pump bolt of a coolant shielding motor of an passive advanced pressurized water reactor. Background In some engineering constructions, such as nuclear power plant equipment, where the primary pump of the reactor coolant shield motor is the heart site and the pump housing is the fixed, pressurized and protective housing of the primary pump, the two are tightly combined to form an integral key piece of equipment. In the prior art, the connection of equipment is mainly finished by welding and bolts, the main pump and the pump shell are required to be fastened or detached by using large bolts and nuts, and the large bolts and nuts are mainly fastened or detached by using two methods of hydraulic spanners or hot stretching, however, the inventor of the present application discovers that the two methods have some problems in the process of connecting the main pump and the pump shell. The problem that the hydraulic wrench is fastened or detached is that with the increase of the specification of the bolt, the required torque is increased, the large-sized bolt and the nut cannot find a proper hydraulic wrench, and a certain space is needed for installing a corresponding device in the moment beating stage of the hydraulic wrench. The problems of the hot stretching include expansion after the bolts are heated and change in length in the hot stretching process, and the shortening amount of connecting bolts in the equipment is basically consistent in order to keep the locking force of the equipment consistent in the circumferential direction, but the problems of inconsistent elongation caused by the influence of heating of adjacent surrounding bolts due to the fact that the main pump of a reactor coolant shielding motor and a pump shell have compressible amounts, the bolts are different in physical properties and stretching sequence and the like, and the problem of inconsistent elongation caused by the fact that each group of bolts are different in elongation after one-time stretching is finished. Disclosure of Invention The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention aims to provide a passive advanced pressurized water reactor coolant shielding motor main pump bolt hot stretching method. In order to achieve the above purpose, the invention provides a passive advanced pressurized water reactor coolant shielding motor main pump bolt hot stretching method, comprising the following steps: s1, numbering all bolt holes on a pump shell and numbering all bolts to be installed; s2, grouping the numbered bolt holes, and grouping the numbered bolts; S3, setting a planned elongation, namely setting a planned elongation of B 1, wherein B 1 is required to meet the requirement of the stretching amount A of a single bolt and the average value C of the stretching amounts of all bolts; s4, performing first hot stretching on the bolts according to groups; s5, performing secondary hot stretching on the bolts according to groups; and S6, carrying out heat balance stretching on the bolts which do not meet the planned elongation B 1 until all the bolts meet the planned elongation B 1. Further, the pump shell is provided with 24 bolt holes, the number of the bolt holes is 1# -24#, and correspondingly, the number of the bolts is 24, and the number of the bolts is 1-24. Further, bolt holes numbered 1#, 4#, 7#, 10#, 13#, 16#, 19#, 22# are divided into a first set of bolt holes, bolt holes numbered 2#, 5#, 8#, 11#, 14#, 17#, 20#, 23# are divided into a second set of bolt holes, bolt holes numbered 3#,6#,9#,12#,15#,18#,21#,24# are divided into a third set of bolt holes, and correspondingly, bolt holes numbered 1, 4, 7, 10, 13, 16, 19, 22 are divided into a first set of bolts, bolt holes numbered 2,5, 8, 11, 14, 17, 20, 23 are divided into a second set of bolts, and bolt holes numbered 3,6,9,12,15,18,21,24 are divided into a third set of bolts. Further, the specific steps of the first hot stretching in the step S4 are as follows: S401, performing first hot stretching on a third group of bolts, loading the third group of bolts into the first group of bolt holes, pre-installing nuts on the third group of bolts, heating the third group of bolts by using a bolt heater, rotating the nuts E 1 after heating, measuring the third group of bolts by using a measuring instrument after cooling, and measuring that the elongation of the first hot stretching of the third group of bolts is B 2; S402, welding a first part of a C-shaped connecting surface of the pump shell and the main pump, which is not blocked by a bolt; S403, performing first hot stretching on the second group of bolts, loading the second group of bolts into the second group o