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CN-121678073-B - Prefabricated welding and airtight inspection method for refrigeration pipeline of refrigeration house

CN121678073BCN 121678073 BCN121678073 BCN 121678073BCN-121678073-B

Abstract

The invention relates to the technical field of pressure pipeline air tightness detection, and discloses a method for prefabricating, welding and air tightness inspection of a refrigeration pipeline of a refrigeration house; the method is used for solving the problems that the stability, repeatability and traceability of tiny leakage are difficult to realize and the threshold quantification are difficult to realize in the traditional method, and the method comprises the steps of firstly determining a boundary data sheet and valve position isolation check, accessing dry nitrogen, a reference cavity, a double-pressure link and near-far-end temperature measuring points, recording initial parameters, completing self-checking of switching of the take-over link and the valve position under the working condition of the reference cavity, pre-charging and target pressure step-charging and pressure temperature threshold gate-controlled voltage stabilization, synchronously acquiring pressure temperature data of a section to be checked and the reference cavity in a main pressure maintaining period, periodically checking cross check drift, and checking the triggering condition according to single-step isolation of a single valve in a partition to obtain the stability, repeatability and traceability judgment conclusion of tiny leakage.

Inventors

  • LI JIE
  • LIU LIXIA

Assignees

  • 上海浩爽实业有限公司
  • 上海冷迪实业有限公司

Dates

Publication Date
20260508
Application Date
20260209

Claims (9)

  1. 1. The method for prefabricating, welding and airtight inspection of the refrigeration pipeline of the refrigeration house is characterized by comprising the following steps of: S1, acquiring a boundary of a section to be detected, completing valve position isolation, accessing a dry nitrogen gas supply link, a reference cavity, two pressure measurement links and temperature measurement points, and recording initial parameters; S2, connecting a reference cavity to execute self-checking of a take-over link and valve position switching self-checking, after the self-checking passes, changing a section to be checked, after the self-checking passes and changes a pressure measuring port of the section to be checked, executing partition isolation checking, freezing partition checking pressure and partition allowable difference threshold, and when any partition meets a non-environmental-leading trigger caliber, terminating the rest partition checking and forming partition checking records and final detection records, wherein a reference consistency condition adopts an allowable difference limit reference field of a pressure maintaining task list, an allowable difference statistical caliber reference field and a direction judging caliber reference field, and the allowable difference statistical caliber is identical to the pressure change direction of the section to be checked and the pressure change direction of the reference cavity, and does not exceed the allowable difference limit, meets the condition of being marked as an environmental-leading window, and does not meet the condition of being marked as a non-environmental-leading window; S3, grading and inflating according to the pre-inflation pressure and the target detection pressure, and executing voltage stabilization between stages, wherein the voltage stabilization ending condition is that the pressure change does not exceed a threshold value and the temperature change does not exceed the threshold value; S4, synchronously collecting pressure and temperature data of a section to be detected and a reference cavity during main pressure maintaining, periodically executing connection pipe verification and link cross verification, and judging according to consistency conditions; and S5, when judging that the rechecking condition is met, executing partition isolation rechecking, switching valve positions according to the partition sequence, repeating pressure maintaining and rechecking, and recording detection data.
  2. 2. The method for prefabricating, welding and airtight inspection of a refrigeration pipeline of a refrigeration house according to claim 1, wherein the steps of obtaining the boundary of a section to be inspected and completing valve position isolation, accessing a dry nitrogen gas supply link, a reference cavity, two pressure measurement links and temperature measurement points, and recording initial parameters include: establishing a boundary data sheet and completing valve position isolation, checking by valve position double persons to generate a valve position state code, and executing blind cap plugging or replacing an indicator when no indication exists in the valve position; the air supply link is provided with filtering and drying and rechecks by using the difference limit of the air supply side and the side pressure difference to be detected; And accessing the reference cavity, the two pressure links and the near-far-end temperature measuring point, and updating the version number of the initial parameter table when the measuring point is changed.
  3. 3. The method for prefabricating, welding and airtight inspection of a refrigeration pipeline of a refrigerator according to claim 1, wherein the connecting reference cavity performs self-inspection of a take-over link and self-inspection of valve position switching, comprising: After the connection reference cavity executes the self-checking of the take-over link and is changed, generating a partition boundary table and a rechecking plan when the main pressure maintaining meets the rechecking trigger caliber; and switching the zoned valve positions according to a single step of the single valve, waiting for the pressure disturbance attenuation after switching, and then carrying out zoned pressure stabilization and zoned pressure maintaining and executing cross check.
  4. 4. The method for prefabricating, welding and airtight inspection of a refrigerating pipeline of a refrigerator according to claim 1, wherein the step of inflating according to the pre-filling pressure and the target detection pressure comprises the steps of: when the gas is filled in stages according to the pre-filling pressure and the target detection pressure, generating an inflation scheme table and freezing the upper limit of the two-stage inflation rate, the length of a voltage stabilizing window, the maximum voltage stabilizing duration, a safety threshold and the upper limit of the pressure relief rate; And stopping boosting and writing the partition rechecking to-do information when the pressure drop in the obvious leakage trigger window exceeds the obvious leakage pressure drop threshold value.
  5. 5. The method of claim 1, wherein the inter-stage pressure stabilization is performed, and the pressure stabilization ending condition is that the pressure change does not exceed a threshold value and the temperature change does not exceed a threshold value, comprising: When the interstage voltage stabilization is executed, the voltage stabilization ending condition takes the value that the difference between the maximum value and the minimum value of the pressure in the length of the voltage stabilization end section is not more than the pressure change threshold value, and the difference between the maximum value and the minimum value of the temperature of the near end and the far end is not more than the temperature change threshold value; And judging and recording the marks and the early warning starting point time stamps according to the reference cavity direction, wherein the master pressure maintaining task list refers to the time stamps and the event code enumeration values.
  6. 6. The method for prefabricating, welding and airtight inspection of a refrigeration pipeline of a refrigerator according to claim 1, wherein the step of synchronously collecting pressure and temperature data of a section to be inspected and a reference cavity during main pressure maintaining comprises the steps of: When synchronously collecting pressure and temperature data of a section to be detected and a reference cavity during main pressure maintaining, generating a pressure maintaining task list, wherein the task list at least sets main pressure maintaining duration, sampling period, judging window length and re-checking period; Establishing a time sequence record table, wherein the record table is at least provided with sampling time, two pressure link readings, a reference cavity pressure reading, a near-end temperature, a far-end temperature, a valve position state code, a stage state code and a sampling quality mark; When the sampling quality mark meets the preset abnormal condition, recording an evidence interruption mark.
  7. 7. The method for prefabricating, welding and airtight inspection of a refrigerating pipeline of a refrigerator according to claim 1, wherein the steps of periodically performing connection pipe verification and link cross verification, and judging according to consistency conditions include: when the taking over and the link cross-checking are periodically executed, switching the pressure measurement link to the reference cavity according to the checking period and keeping the cross-checking duration, and then switching back to the section to be checked and entering a back switching stable section; Performing verification according to the verification threshold and the drift threshold, and sequentially executing verification, link maintenance and short-range verification of the reference cavity when the verification fails, and resetting window counting; And generating a window judging table according to the temperature consistency, the reference consistency and the link consistency, and writing in the rechecking trigger caliber.
  8. 8. The method for prefabricating, welding and airtight inspection of a refrigerating pipeline of a refrigerator according to claim 1, wherein when it is determined that a rechecking condition is satisfied, performing partition isolation rechecking comprises: When judging that the checking condition is met, executing partition isolation checking, generating a partition boundary table and a checking schedule table, and freezing partition checking pressure, a voltage stabilizing window, a pressure maintaining duration, an allowable difference threshold and a checking period; The rechecking evidence starting point takes the starting and ending time stamp of the trigger window.
  9. 9. The method for prefabricating, welding and air tightness testing of a refrigerating pipeline of a refrigerator according to claim 1, wherein the steps of switching valve positions in a zoning order, repeating pressure maintaining and verification, recording detection data, and comprising: When the valve positions are switched according to the zoning sequence and zoning pressure maintaining and verification are carried out, the valve position switching is carried out according to a single valve step, and the valve position state code and the switching time are recorded; after valve position switching, entering a voltage stabilizing gate control through a waiting section, and executing reference cavity verification and double-pressure link drift verification; And when the subareas meeting the non-environmental dominant trigger caliber appear, stopping rechecking of the rest subareas, and generating subarea rechecking records and final detection records.

Description

Prefabricated welding and airtight inspection method for refrigeration pipeline of refrigeration house Technical Field The invention relates to the technical field of pressure pipeline air tightness detection, in particular to a prefabricated welding and air tightness detection method for a refrigeration pipeline of a refrigeration house. Background The pipeline of the refrigeration house refrigerating system generally comprises a liquid supply pipe, an air return pipe, an exhaust pipe, a valve connector and the like, air tightness detection is needed after the pipeline is prefabricated and welded, whether leakage exists at a welded junction and a connecting part is judged, follow-up vacuumizing is prevented, refrigerant is filled, and leakage accidents occur after operation, so that reworking and safety accidents are caused. At present, the air tightness detection is carried out in a nitrogen filling and pressure maintaining mode in the engineering site, namely, nitrogen or mixed detection gas is introduced into a detection pipeline to reach a set pressure for pressure maintaining, and whether the air tightness is qualified is judged according to the pressure change after the pressure maintaining; For example, the published patent application CN104075106B provides a control method and a control device for a nitrogen-charging, pressure-maintaining and vacuum-pumping device, and the detection operation is completed by controlling the processes of nitrogen charging, pressure maintaining, vacuum pumping and the like. The disclosed invention patent application CN110095237B provides a leak detection method of a refrigerating system, which combines the steps of primary vacuumizing, vacuum pressure maintaining, filling detection gas, gun leakage detection, pressure maintaining test, secondary vacuumizing and the like to complete leak detection operation. The scheme takes pressure change in the pressure maintaining stage as a judgment basis, or the scheme is positioned by a leak detection tool; However, in the on-site nitrogen filling and pressure maintaining detection of the refrigeration pipeline of the refrigeration house, the pressure change is not caused by leakage of the detected object. Because the on-site environment temperature of the refrigeration pipeline of the refrigeration house changes along with the state of the gas filling under the influence of day and night, the start and stop of the fan and sunlight, the pressure is enabled to rise and fall independently of leakage. The long pipe section and the multiple branches lead to uneven temperature field and larger thermal inertia, local temperature change lag leads to delay and rebound of pressure signals, detection results of different pipelines are inconsistent at different time, zero drift of the pressure sensor and acquisition link errors lead to the superposition of drift amount in pressure difference, so that micro leakage and instrument drift are difficult to distinguish, and then, the micro leakage of a test connection pipe, a quick connector and a hose can be led into leakage channels of non-measured objects, so that the pressure attenuation sources are unknown. The above-mentioned non-measured object factors will cause aliasing of the pressure change signal and the true micro leakage signal, so that stable, repeatable and traceable qualification judgment and threshold quantification of the micro leakage are difficult to realize without dismantling the system and introducing additional pollution, resulting in erroneous judgment, missed judgment, repeated pressurization retest, uncontrolled delivery cycle and other results. Therefore, an improved method for detecting nitrogen filling, pressure maintaining and air tightness of a refrigeration pipeline of a refrigeration house is needed, and the improved method is used for inhibiting or stripping the influence of temperature fluctuation, thermal inertia, instrument drift and inspection adapter leakage on judgment, realizing high confidence judgment and traceable recording of tiny leakage, and obtaining the technical effects of stable detection conclusion and controllable positioning and rechecking cost. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a method for prefabricating, welding and airtight inspection of a refrigeration pipeline of a refrigeration house, which solves the problems that the stability, repeatability and traceability of tiny leakage are difficult to realize and the qualification judgment and threshold quantification are difficult to realize in the traditional method. In order to achieve the above purpose, the present invention provides the following technical solutions: A method for prefabricating, welding and airtight inspection of refrigeration pipelines of a refrigeration house comprises the following steps: S1, acquiring a boundary of a section to be detected, completing valve position isolation, accessing a dry nitrogen gas supply l