CN115247979B

CN115247979B - Preventive maintenance method applied to advanced repair of composite radiator

Info

Publication number: CN115247979B
Application number: CN202210641812.9A
Authority: CN
Inventors: 徐世武; 王建强; 刘文斌; 于红军
Original assignee: Tianjin Locomotive Co ltd
Current assignee: Tianjin Locomotive Co ltd
Priority date: 2022-06-08
Filing date: 2022-06-08
Publication date: 2024-10-25
Anticipated expiration: 2042-06-08
Also published as: CN115247979A

Abstract

A preventive maintenance method applied to advanced repair of a composite radiator, comprising the steps of: (1) wind fin cleaning; (2) cleaning the inner cavity and checking the pollution degree; (3) drying the inner and outer surfaces; (4) a sealability test; (5) overhauling; (6) detecting ventilation quantity; (7) exterior paint. The invention has the advantages of short working period, low material cost and high working efficiency, and can fully expose hidden faults of the radiator. The maintained radiator can continuously run for more than 110 ten thousand kilometers, the reliability of products is guaranteed, and the purposes of comprehensively detecting and recovering the performance of the radiator are achieved.

Description

Preventive maintenance method applied to advanced repair of composite radiator

Technical Field

The invention belongs to the technical field of maintenance of rail transit equipment, and particularly relates to a preventive maintenance method for an advanced maintenance stage of a composite radiator.

Background

Main transformers and main converter devices assembled on main stream high-power electric locomotives and motor train units of the current railways all adopt plate-fin type radiators to cool working media. The working environment of the radiator is often accompanied with wind, sand, rain and snow weather, and salt fog, acid rain and sand storm are frequent. Common faults include a reduction in cooling efficiency due to blockage of the wind fins, leakage of the radiator, and the like. According to the requirements of users, when the electric locomotives and motor train units carry out advanced repair procedures (locomotive C5 and C6 repair and power centralized motor train unit D4 and D5 repair), the oil and water radiators are required to be removed for maintenance, internal and external cleaning and tightness tests are carried out, the basic performance is recovered, and the heat dissipation effect of the main transformer and the converter device is ensured.

At present, the oil and water radiator has no unified maintenance technical specification, the maintenance method is not uniform, the detection process is imperfect, and the oil and water radiator is generally only subjected to tightness test and external cleaning and is not subjected to thorough inner cavity cleaning and detection. During the manufacturing, assembling and working processes of the transformer, the converter and the composite cooler, generated impurities remain in the inner cavity to influence the insulating property of transformer oil and cause pollution of cooling liquid of the converter.

The method for the tightness test and the inner cavity pollution test is provided in the enterprise standard Q/CR 688-2019 composite cooler for electric locomotives and electric motor train units of the railway head company. The tightness test steps are as follows: the tightness test of the inner cavity of the cooler adopts a water immersion air pressure mode, and a) the water cavity of the composite cooler is connected with a special test system. b) The composite cooler water cavity is fully immersed in water, the test pressure is adjusted to a specified value, and the pressure is maintained for at least 30min. c) The composite cooler was observed for the presence of bubbles. d) Test pressure, time and leakage were recorded. e) The oil cavity tightness test is the same as the water cavity tightness test method. The inner cavity pollution test comprises the following steps: a) Connecting the water cavity of the composite cooler with a special cleaning system with a filter, wherein the filtering precision of the filter is not lower than 100 mu m; b) Cleaning the water cavity of the composite cooler; c) After the cleaning is finished, visually inspecting the filter to confirm that no dirt exists in the filter; d) Checking the inside of the water cavity of the composite cooler by using an endoscope to confirm that no foreign matters exist in the water cavity; e) The oil cavity pollution test is the same as the water cavity pollution test. The disadvantages are: a) What kind of cleaning agent is suitable for cleaning the inner cavity, and no specific method or requirement is given; b) How the cleaning liquid left after cleaning is removed does not give a specific method; c) The two standard contents are suitable for the new product manufacturing process, and have no requirement on the development time of the tightness test and the inner cavity pollution test. Practical experience shows that if tap water is used for preparing cleaning liquid for cleaning the inner cavity, chloride ions in the cleaning liquid can cause electrochemical corrosion to the aluminum alloy cavity; if cleaning liquid remains after cleaning, the water content index of the transformer oil can be adversely affected.

The prior art does not provide a complete and correct process flow for preventive maintenance of the plate-fin radiator, cannot ensure the reliability of the radiator after maintenance, and has a great distance from the user requirement of 'recovering basic performance'.

Disclosure of Invention

In order to solve the above problems in the prior art, the present invention provides a preventive maintenance method applied to advanced repair of a composite radiator.

The technical scheme of the invention is as follows:

A preventive maintenance method applied to advanced repair of a composite radiator, characterized by comprising the following steps:

(1) Cleaning wind fins: dust is collected by a 3-5kw high-power industrial dust collector, and the surface is brushed by a bristle brush while dust is collected; then placing the radiator into a cleaning tank, preparing a chemical cleaning agent and water into a cleaning solution, and pouring the cleaning solution into the cleaning tank; the cleaning pool is provided with a water pump, and the liquid level of the cleaning liquid is more than 150mm at the water inlet of the water pump; the cleaning liquid flows out through a water pump and a spray cleaning device, flows down above the radiator, and vertically sprays and washes the air fins for at least 2 hours; after the spray cleaning is finished, the radiator is lifted out of the cleaning pool, the fins are vertically washed by a high-pressure cleaning water gun, and surface dirt and cleaning liquid are washed cleanly; the distance between the water outlet pipe orifice of the cleaning gun and the fin is not less than 80mm;

(2) Inner cavity cleaning and pollution degree inspection: the inner cavity cleaning and pollution degree inspection are carried out on an inner cavity cleaning test bed:

Cleaning an inner cavity: when in cleaning, deionized water and chemical cleaning agents are adopted to prepare cleaning liquid, the oil cavity and the water cavity are respectively washed, and after the cleaning is finished, the oil cavity and the water cavity are respectively rinsed by clean deionized water;

Pollution degree inspection: the inner cavity cleaning test bed water outlet and return pipelines are respectively provided with a Y-shaped metal filter screen filter, the filter precision of the filter screen is not lower than 100 mu m, the impurity residue condition of the filter screen of the return pipeline filter is visually checked after rinsing, no impurity and foreign matter residue are regarded as qualified, and if the impurity and foreign matter residue do not meet the condition, the cyclic flushing is continued until the condition is met;

(3) Drying the inner surface and the outer surface: comprises three steps of draining, drying and checking,

And (3) draining: opening a deflation screw plug of the radiator, and placing a deflation hole at the bottom; connecting an air pipe with an inlet of a radiator, connecting the air pipe with an air storage tank, forcing the accumulated water in the inner cavity to be discharged from a vent hole by compressed air, and continuously purging to remove the accumulated water;

And (3) drying: putting the composite radiator into an electric oven, and continuously filling compressed air into the inner cavity of the radiator for purging in the drying process;

checking: after drying, a transparent high-temperature adhesive tape is stuck to the flange at the inlet and outlet of the cooler, and after the temperature is reduced to normal temperature, if no water mist is condensed, the drying is qualified;

(4) Tightness test: the tightness test must be carried out after drying. The water cavity of the composite cooler is connected with a test wind source in a water immersion air pressure test mode, the composite cooler is fully immersed in water, the test pressure is regulated to a specified value according to the specified test pressure, whether bubbles appear on the surface of the cooler or not is observed, if the bubbles appear, the test time is prolonged, the observation is continued, the misjudgment is avoided, and if the bubbles continuously appear at one position to escape, the leakage fault is judged to exist;

(5) And (3) overhauling: the method comprises the steps of leakage fault treatment, fin centering, fastener replacement and sealing piece replacement, wherein a radiator with leakage faults is repaired or replaced by adopting a method of welding repair, bonding and/or core replacement; straightening the lodged fins one by using tweezers; replacing the rubber sealing gaskets of the process plugs and the sealing surfaces of all parts; replacing the detached fastener; after maintenance, checking that the lodging and plugging area of the fins is not more than 5% of the total ventilation area;

(6) And (3) ventilation quantity detection: after the cooler is cleaned and assembled, using a qualified composite cooler ventilator under the vehicle as a wind source to detect the ventilation quantity, placing the composite cooler on a special frame, suspending the lower part of the composite cooler, and respectively measuring wind speed values of a plurality of points at the wind outlet end of the composite cooler by a wind speed measuring instrument under the rated working condition of a composite cooler ventilator set, wherein the average wind speed is not less than 10m/s;

(7) And (3) exterior paint: and (3) carrying out surface paint repair on the composite radiator according to design requirements, wherein the paint surface is complete, the phenomena of missing coating, sagging and stripping are avoided, and the paint film adhesive force reaches the 1-level standard specified in GB/T9286.

Preferably, in the step (1), the ph=7 to 8 of the cleaning liquid is prepared.

Preferably, in the step (2), deionized water with the conductivity not more than 10 mu s/cm is adopted during cleaning; respectively circularly flushing the oil cavity and the water cavity for 30min; and after the cleaning is finished, rinsing the oil cavity and the water cavity respectively for 5-10min by clean deionized water.

Preferably, in the step (3), a gas storage tank with a capacity of 300-500 liters is adopted, and compressed air with a pressure of 0.4-0.6MPa is used.

Preferably, in the step (3), the drying temperature is 130-150 ℃ and the drying time is 3-5h; the drying box is provided with a rail and a flatcar.

Preferably, 9 points of wind speed values are measured in step (6).

Preferably, in the maintenance process of the composite radiator, an outer cover type process protection cover is used for protecting oil and water inlet and outlet pipe orifices of the radiator in the whole process.

The invention has the following technical effects:

the maintenance requirement of the locomotive and motor train unit composite radiator in the advanced maintenance stage is to recover the basic performance of the radiator. Typical failure modes of the composite radiator in use are two types, namely, blockage of a radiating fin, leakage of cooling liquid, pollution of an inner cavity, aging of a sealing element and poor fastening.

Cooling fin blocking failure: occurs in the air side channels of the radiator. The air side channel of the composite radiator is of a plate-fin structure, and because gaps among radiating fins are smaller, when the composite radiator is used in spring, poplar flowers, catkin, sand dust and shellac in the air directly enter the composite radiator through the ventilating window of the vehicle top cover, and the composite radiator is easy to block between the radiating fins to cause blockage, so that the ventilation and heat dissipation effects are affected. The formed dirt also has larger thermal resistance, and influences the heat conduction performance of the fins. Related technical specifications require that the maximum blocking rate is not more than 5% of the total heat dissipation area, and the average wind speed of the air outlet of the radiator is not less than 8m/s after the loading operation

Cooling liquid leakage failure: typically occurs on the surface of the radiator core, primarily through-hole leakage due to electrochemical corrosion. The formation causes are: dust, greasy dirt, floccules, shellac and the like on the air side channel are retained on the surface of the aluminum material, and have a certain corrosion effect on the aluminum material. In the rain water and wet weather, the wet air or rain water entering through the air duct and the attachments on the surface of the body form a mixed solution, and active anions (such as 'Cl ^-') in the solution can form pitting corrosion on the surface of the aluminum alloy body, so that 'active-passivation' corrosion cells are formed, and electrochemical corrosion is caused. Once the passivation layer on the surface of the aluminum alloy material is destroyed, electrochemical corrosion phenomenon of 'large cathode and small anode' is formed, the accumulated effect is continuously exerted on the destroyed part, and perforation leakage phenomenon occurs when serious, so that the cooling liquid leakage fault is caused.

Failure of lumen contamination: the formation reasons mainly include the peeling of brazing materials generated during the manufacturing of the composite radiator, and the reasons such as the wetting and ageing of transformer oil, internal discharge, metal particles generated by the running abrasion of an oil pump gear, the emulsification of cooling liquid of a converter device and the like.

Seal aging failure: the rubber seal itself life problems.

Poor fastening: the fastener fails.

The scheme of the invention combines the user requirements and the typical application faults of the radiator, and rationalizes the operation flow and the operation method. The scheme comprises the following steps: cleaning air fins, cleaning an inner cavity, checking pollution degree, drying inner and outer surfaces, testing tightness, treating leakage faults, righting the fins, replacing fasteners and sealing elements, detecting ventilation quantity, painting the appearance, installing overhaul labels and the like.

The scheme of the invention designs a scientific and reasonable process flow. Wherein, deionized water with conductivity not more than 10 mu s/cm and chemical cleaning agent are adopted to clean the inner cavity, thus avoiding potential damage of active anions in tap water to the surface of the body; the inner cavity is dried before the tightness test, so that adverse influence of residual accumulated liquid in the inner cavity on the test accuracy is prevented; when the radiator is heated during drying, high-pressure air is introduced into the radiator to purge and accelerate drying; the ventilation area of the air side channel is ensured by adopting the mode of detecting the ventilation quantity under the vehicle, namely, the air side channel has enough cooling (area) allowance.

Specific:

1. The scheme of the invention designs finish and reasonable process flow, and the process flow comprises the following steps: cleaning air fins, cleaning an inner cavity, checking pollution degree, drying inner and outer surfaces (dewatering, drying and checking), testing tightness, overhauling (leakage fault treatment, fin righting, fastener and sealing element replacement), detecting ventilation quantity, painting the outer surface, installing overhauling labels, protecting and the like.

2. The cleaning process adopts deionized water with the conductivity not more than 10 mu s/cm and chemical cleaning agents to clean the inner cavity and the outer surface, and the cleaning process is divided into two stages of cleaning and rinsing, so that the adverse effect of active anions in tap water on the surface of the body is avoided.

3. The internal contamination level inspection was performed using a Y-filter connected to a dedicated cleaning system. And after cleaning, adopting a method of integral drying and internal purging to dry the surface moisture of the radiator. And (5) drying and then carrying out a tightness test, and checking the sealing state of the core body and the connecting pipeline thereof. And the inner cavity is dried before the tightness test, so that the adverse effect of residual effusion in the inner cavity on the test accuracy is prevented.

4. And in the drying process, the radiator is heated, and meanwhile, compressed air of 0.4-0.6MPa is introduced into the radiator to purge the generated water vapor, so that the completion of the drying process is accelerated.

5. After the drying is finished, a transparent high-temperature adhesive tape is stuck on a water (oil) inlet and outlet pipe orifice, and after the temperature is reduced to normal temperature, whether the inner cavity is dried or not is judged according to whether the adhesive tape has the dewing phenomenon or not.

6. The oven in the drying process is provided with a rail and a trolley, so that the radiator can conveniently get in and out.

7. After the overhaul of the composite radiator is completed, the composite radiator is connected with a qualified test re-cooling ventilator unit under the vehicle, the average wind speed of an air outlet of the composite radiator is tested under the rated working condition of a fan, and the cooling (area) allowance of the radiator is checked to meet the specified requirement. The ventilation quantity detection is carried out in a mode that the qualified ventilator unit detects the wind speed under the vehicle, so that the sufficient ventilation area of the air side channel is ensured, and reworking caused by unqualified wind speed test after the radiator with the blocking phenomenon is loaded is prevented.

8. The ventilation quantity detection uniformly collects the wind speeds of nine positions at the outlet of the radiator, the average wind speed is more than 10m/s square, the average wind speed is regarded as qualified, the judgment standard is 1.25 times of the requirement of the loading test, and the cooling capacity of the radiator is further ensured to be large enough.

The preventive maintenance method applied to advanced maintenance of the composite radiator is suitable for preventive detection and maintenance of all plate-fin radiators in advanced maintenance, has reasonable process flow design, comprehensively considers various typical faults possibly occurring in the running process of loading the radiator, and has the characteristics of high reliability and good detection accuracy.

The process method has the advantages of short working period, low material cost and high working efficiency, and can fully expose hidden faults of the radiator. The maintained radiator can continuously run for more than 110 ten thousand kilometers, the reliability of products is guaranteed, and the purposes of comprehensively detecting and recovering the performance of the radiator are achieved.

The preventive maintenance technology provided by the invention can be used for comprehensively repairing and comprehensively detecting typical faults of the radiator after a certain period of time is applied, such as: wind fin clogging, cavity contamination, core leakage, seal aging, poor fastening, and the like. The method has strong guidance on the on-site work, ensures the reliability of the maintained radiator, and meets the user requirement of recovering the basic performance.

Drawings

FIG. 1 is a schematic diagram of a composite heat sink according to embodiment 1;

FIG. 2 is a schematic diagram of the lumen cleaning operation in step (2) of example 1;

FIG. 3 is a schematic drying diagram of step (3) of example 1;

FIG. 4 is a schematic diagram showing the ventilation test in the step (6) of the embodiment 1;

fig. 5 is a schematic diagram of the ventilation amount detection position in step (6) of embodiment 1;

FIG. 6 is a schematic view of the special stand in step (6) of example 1;

FIG. 7 is a flow chart of the overall process of example 1;

fig. 8 is a schematic perspective view of a composite radiator according to embodiment 1;

fig. 9 is an enlarged view of a portion of the fin of fig. 8.

The reference numerals in the figures are as follows:

1-a composite radiator; 2-water inlet and outlet pipes; 3-a water radiator; 4-oil radiator; 5-a screw plug; 6-oil inlet and outlet pipes; 7-a chassis; 8-an electric drying box; 9-flatcar; 10-flatcar track; 11-an air storage tank, 12-an air pipe, 13-an electric heater, 14-a blower, 15-a ventilator unit, 16-a special bracket, 17-an anemometer and 18-fins.

Detailed Description

For a better understanding of the present invention, the present invention will be further explained below with reference to the drawings and examples.

Example 1

As shown in fig. 1 and 8, the composite radiator 1 of the present embodiment has a water inlet and outlet pipe 2 and an oil inlet and outlet pipe 6 respectively on an upper side water radiator 3 and a lower side oil radiator 4, a screw plug 5 is provided on a side surface, and a bottom frame 7 is provided below the oil radiator 4.

As shown in fig. 7, the present embodiment includes the steps of:

(1) Cleaning wind fins: the surface was cleaned with a 3-5kw high power industrial cleaner, and the surface was brushed with a bristle brush while cleaning the dust, to remove thicker dust and dirt from the fins 18 of the radiator, as shown in fig. 8 and 9. After dust collection, the radiator is placed in a cleaning tank, chemical cleaning agent and water are prepared into cleaning liquid according to a specified proportion, the cleaning liquid is poured into the cleaning tank, the proportion is adjusted according to different cleaning agents, for example DRJ-2 aircraft surface cleaning agent and water are prepared according to a proportion of 1:3-1:5. The cleaning tank is provided with a water pump, the liquid level of the cleaning liquid is more than 150mm at the water inlet of the water pump, preventing the water pump from idling. The cleaning liquid flows out through the water pump and the spray cleaning device, flows down above the compound radiator 1, and vertically sprays and washes the fins 18 for at least 2 hours, so that dirt and workpieces on the surfaces of the fins 18 are decomposed and stripped, and then the dirt and workpieces are washed into a pool. After the spray cleaning is completed, the composite radiator 1 is lifted out of the cleaning pool and is stably placed on a special working frame. The fins 18 are washed vertically by a high-pressure water gun from left to right in sequence, and surface dirt and cleaning liquid are washed clean. The water outlet of the cleaning gun is not less than 80mm away from the fins, so that the fins 18 are prevented from lodging due to excessive pressure.

The PH=7-8 of the prepared cleaning liquid, the solution is neutral and can be directly discharged.

(2) Inner cavity cleaning and pollution degree inspection: as shown in fig. 2, both cleaning and contamination level inspection were performed on an internal cavity cleaning bench. The cleaning of the inner cavity is divided into two stages of cleaning and rinsing.

Cleaning an inner cavity: during cleaning, deionized water with conductivity not more than 10 mu s/cm and chemical cleaning agent are adopted to prepare cleaning liquid according to a certain proportion, the cleaning liquid is filled into a cleaning liquid tank positioned on the inner cavity cleaning test bed, and the cleaning liquid tank respectively circularly washes an oil cavity and a water cavity for 30min under the action of a water pump through a circulating pipeline. And after the cleaning is finished, rinsing the oil cavity and the water cavity respectively for 5-10min by clean deionized water. The cleaning liquid tank can be further connected with the pure water tank for rinsing and the water treatment equipment through a one-way valve.

Pollution degree inspection: the water outlet pipeline and the water return pipeline of the inner cavity cleaning test bed are respectively provided with a Y-shaped metal filter screen filter, and the filtering precision of the filter screen is not lower than 100 mu m. And visually checking impurity residue condition of the filter screen of the water return pipeline filter after rinsing, and if no impurity or foreign matter residue exists, judging the filter screen to be qualified. If the condition is not satisfied, the cyclic flushing is continued until the condition is satisfied.

After the cleaning is completed, the inside of the radiator cavity is checked by an endoscope to confirm that no foreign matters remain.

(3) Drying the inner and outer surfaces (dewatering, drying, checking): after the inner cavity pollution degree is checked and before the tightness test, the inner cavity of the radiator is in a relatively dry state by drying, so that the accuracy of the tightness test is prevented from being influenced by residual effusion in the inner cavity.

And (3) draining: opening a bleeder screw 5 of the radiator, and placing a bleeder hole at the bottom; the air pipe 12 is connected with the inlet and outlet of the compound radiator 1, the air pipe 12 is connected with a gas storage tank 11 with the capacity of 300-500 liters, and the compressed air with the pressure of 0.4-0.6MPa is used for forcing the water in the inner cavity to be discharged from the air vent and continuously purging the water to remove the water. The purpose of the air reservoir 11 is to provide a sufficient amount of compressed air to provide a greater displacement and to facilitate drainage of the accumulated water inside the radiator than if the air reservoir was purged directly with an air duct.

And (3) drying: as shown in fig. 3, the composite radiator 1 is placed in an electric drying box 8, the drying temperature of an electric heater 13 is 130-150 ℃, a blower 14 is arranged at the top, and the drying time is 3-5h. The electric drying box 8 is provided with a flat car rail 10 and a flat car 9, so that workpieces can be conveniently moved in and out. In the drying process, compressed air is continuously filled into the inner cavity of the composite radiator 1 to be purged, and the water vapor formed in the inner cavity is discharged in an accelerating way while the whole radiator is heated, so that the drying time can be greatly shortened.

Checking: and (3) after drying, sticking the product on an inlet flange and an outlet flange of a cooler by using a transparent high-temperature adhesive tape, and after cooling to normal temperature, if no water mist is condensed, judging that the product is qualified for drying.

(4) Tightness test: the tightness test must be carried out after drying. The tightness test adopts a water immersion air pressure test mode, a water cavity of the composite radiator 1 is connected with a test air source, the composite radiator 1 is fully immersed in water, the test pressure is regulated to a specified value (the test pressure is 1.5 times of the working pressure), the pressure is maintained for at least 30min, and whether air bubbles appear on the surface of the cooler is observed. If bubbles appear, the test time should be prolonged for continuous observation, so that erroneous judgment is avoided. If the bubble escape continues to occur at one position, it is determined that a leakage fault exists and the bubble escape should be dealt with. The test procedure of the oil cooler 4 is the same as that of the water cooler 3.

(5) Overhauling (leakage fault handling, fin righting, replacement fasteners and seals): the composite radiator 1 with leakage fault must be treated in a manner of repairing by welding, bonding and core replacement according to specific conditions, and the radiator cannot be repaired. The lodged fins are straightened one by forceps. And replacing the rubber sealing gaskets of the process plugs and the sealing surfaces of all parts. And replacing the detached fastener. After overhauling, the lodging and plugging area of the check fins should be no more than 5% of the total ventilation area.

(6) And (3) ventilation quantity detection: as shown in fig. 4, after the composite radiator 1 is cleaned and assembled, a qualified composite radiator ventilator unit 15 is used as a wind source under a vehicle to detect the ventilation quantity, the composite radiator 1 is placed on a special bracket 16 (shown in fig. 6) to suspend the lower part of the special bracket, and under the rated working condition of the composite radiator ventilator unit 15, wind speed values of 9 points are respectively measured at the air outlet end of the composite radiator by a wind speed measuring instrument 17, as shown in fig. 5, the average wind speed is not less than 10m/s (the average wind speed must reach 8m/s after the vehicle is loaded).

The purpose of detecting the ventilation quantity under the vehicle is to detect the blocking condition of the air side channel of the composite radiator 1, if the ventilation quantity does not meet the requirement, the fin side is not thoroughly cleaned, and reworking treatment is needed.

(7) And (3) exterior paint: and (3) carrying out surface paint repair on the composite radiator according to design requirements, wherein the paint surface is complete, and the phenomena of missing coating, sagging and stripping are avoided. The paint film adhesion reaches the 1 grade standard specified in GB/T9286.

Installing an overhaul label: the repair nameplate is adhered and installed at the position 20mm near the manufacturing nameplate of the composite radiator, the printing information on the nameplate comprises a product number, repair date, repair units and the like, and the traceability of the repair process can be realized through the installation of the mark.

Protection: in the maintenance process of the composite radiator, an outer cover type process protective cover is used for protecting oil and water inlet and outlet pipe orifices of the radiator in the whole process, so that foreign matters are prevented from entering.

The method is suitable for preventive maintenance of various types of composite radiators in advanced maintenance stage, and has complete and scientific process flow design and strong operability. The basic performance of the maintained radiator is fully recovered, the reliability is high, and the occurrence rate of operation faults is reduced.

The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes and the like that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered in the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A preventive maintenance method applied to advanced repair of a composite radiator, characterized by comprising the following steps:

(4) Tightness test: the water cavity of the composite cooler is connected with a test wind source in a water immersion air pressure test mode, the composite cooler is fully immersed in water, the test pressure is regulated to a specified value according to the specified test pressure, whether bubbles appear on the surface of the cooler or not is observed, if the bubbles appear, the test time is prolonged, the observation is continued, the misjudgment is avoided, and if the bubbles continuously appear at one position to escape, the leakage fault is judged to exist;

(7) And (3) exterior paint: and (3) carrying out surface paint repair on the composite radiator according to design requirements, wherein the paint surface is complete, and the phenomena of missing coating, sagging and stripping are avoided.

2. The method according to claim 1, wherein in step (1), the PH of the prepared cleaning solution is=7 to 8.

3. The method of claim 1, wherein in step (2), deionized water having a conductivity of not more than 10 μs/cm is used for the cleaning; respectively circularly flushing the oil cavity and the water cavity for 30min; and after the cleaning is finished, rinsing the oil cavity and the water cavity respectively for 5-10min by clean deionized water.

4. The method according to claim 1, wherein in the step (3), compressed air of 0.4 to 0.6MPa is used with a capacity of 300 to 500 liters of air tank.

5. The method according to claim 1, wherein the drying temperature in the step (3) is 130 to 150 ℃ and the drying time is 3 to 5 hours.

6. The method according to claim 1, wherein 9 points of wind speed values are measured in step (6).

7. The method of claim 1, wherein the oil and water inlet and outlet nozzles of the radiator are protected by using an outer cover type process protection cover throughout the maintenance process of the composite radiator.