76 results about "Thermal ageing" patented technology

The invention relates to the technical field of wafer test equipment, in particular to a heating aging test tool which comprises a storage rack and further comprises a wafer clamp placed on the storage rack. The detection assembly comprises a plurality of elastic probes located on one side of the storage rack and a heating disc; and the hot air guide assembly comprises a ventilation male head arranged on one side of the heating disc, an air guide pipe is arranged on the side, away from the ventilation male head, of the heat conduction cover, the air amount in the cavity is gradually decreased from near to far away from the air guide pipe, and the air flow speed is gradually decreased. A hot air flow guide assembly is arranged on a conveying frame, heat of a heating disc is guided to the position above a wafer through airflow through a heat conduction cover, the space above the wafer is divided into a plurality of cavities, the space size and the space shape of each cavity are set, the air flow speed and the contained hot air amount of each space are adjusted, and therefore the heat conduction efficiency of the wafer is improved. The influence of heat loss in the air flow process is reduced, so that the heating effects of all parts of the wafer are similar, and the detection effect is improved.

The invention relates to the technical field of digital twinning, in particular to a digital twinning-based heat dissipation system full-life-cycle predictive maintenance platform, which comprises a data acquisition module; a model construction module; the block division module is used for determining direct partitioning based on the regional coupling strength or related partitioning based on the heat exchange correlation degree according to the fault transfer coefficient; the category analysis module is used for determining a block category based on the temperature deviation degree and determining whether to adjust the block category of the second-class block based on the maximum fluctuation period attenuation rate according to the pollutant deposition influence degree and the thermal aging accumulation rate of the second-class block; the updating analysis module is used for determining the updating frequency of each updating block based on the comprehensive evaluation value; and the updating optimization module is used for determining whether to carry out optimization adjustment or not according to the block change coefficient. The model updating efficiency can be improved.

The invention relates to the technical field of material performance detection, in particular to a rapid testing method for thermal aging failure of an oil and gas pipeline anticorrosive coating material, which comprises the following steps: testing oxidation induction time t of a sample; respectively carrying out thermal aging with different time lengths at 150 DEG C, measuring and calculating A (tri) / A (on) and a melt index change rate, establishing a linear equation of the A (tri) / A (on), and calculating A '(tri) / A' (on) corresponding to 35% of the melt index change rate; carrying out thermo-oxidative aging on the sample at different time lengths, measuring and calculating A (tri) / A (on), and obtaining aging time t'according to A '(tri) / A' (on); carrying out oxidation induction time test on the thermally aged material to obtain a rate coefficient k; and calculating the aging time corresponding to the material failure critical point. The test method provided by the invention can rapidly characterize the thermal aging failure critical point of the anticorrosive coating material, and provides a scientific basis for development of the material.

The invention relates to an electric-thermal combined aging simulation system and an aging simulation method of oiled paper. The system comprises an aging oven, a sealing oil groove arranged in the aging oven, and an electrode module and a temperature control module which are arranged in the sealing oil groove, the sealed oil groove is filled with insulating oil, the electrode module comprises an upper electrode and a lower electrode parallel to the upper electrode, and an oil paper sample is placed between the upper electrode and the lower electrode; the electrode module is used for applying an electric field to the surface of the oiled paper sample to simulate the electrical aging process of the oiled paper sample; and the temperature control module is used for adjusting the temperature of the insulating oil in the sealed oil groove in the process of simulating the electrical aging of the oiled paper sample so as to simulate the process of the combined action of thermal aging and electrical aging of the oiled paper sample. By adopting the method, accurate control of electric-thermal aging can be realized.

The application discloses a kind of thermoset elastomer thermal aging state evaluation method, comprising the following steps: S1, elastomer is treated with heat aging;S2, the maximum elongation of aging sample and positron annihilation lifetime spectrum are tested, and the free volume of aging sample is obtained by analyzing positron annihilation lifetime spectrum;S3, least square method is used to linearly fit the maximum elongation of aging sample and free volume, and the fitting equation of maximum elongation and free volume of elastomer in the process of thermal aging treatment is established;S4, in the actual thermal aging test of the same kind of elastomer, the fitting equation is used, and the maximum elongation of elastomer is calculated by determining the free volume of elastomer, and the thermal aging state of elastomer is evaluated.The application establishes the correlation between the maximum elongation of elastomer and free volume, realizes the thermal aging state of elastomer by free volume, realizes in-situ detection of thermal aging performance, and has high accuracy.

The invention discloses an oil paper insulation life evaluation method, device and equipment of a converter transformer and a medium, and relates to the technical field of electric power engineering, and the method comprises the steps: building an insulation life improvement model based on a linear cumulative damage theory and a thermal aging model; carrying out numerical solution on the electromagnetic field and the solid force field to obtain Lorentz force density and mechanical damage accumulation equivalent stress distribution, and determining an equivalent stress translation factor by utilizing the mechanical damage accumulation equivalent stress distribution; solving numerical values of the oil paper insulation space temperature field and the electromagnetic field to obtain total eddy current loss, and determining a temperature translation factor based on the Lorentz force density, the total eddy current loss and the oil paper insulation space temperature field; calculating total acceleration factor distribution by using the equivalent stress translation factor and the temperature translation factor, inputting the total acceleration factor distribution into the insulation life improvement model, and outputting space life distribution; and carrying out oil paper insulation life evaluation on the converter transformer, realizing quantitative evaluation on insulation fatigue damage under the action of cyclic load, and comprehensively evaluating the life of an insulation material.

This invention discloses a flame-retardant and anti-aging cable composite material and its preparation method, belonging to the field of cable material preparation technology. In this invention, a flame-retardant, high-temperature resistant polysiloxane containing double bonds, an anti-aging agent, and a flame-retardant filler are prepared and blended with raw materials such as EVA and low-density polyethylene. Irradiation causes cross-linking between the materials, endowing the composite material with heat resistance, aging resistance, and good mechanical properties. The anti-aging agent of this invention includes siloxane groups and benzophenone groups, possessing good resistance to both UV aging and heat aging, which is beneficial for further improving the anti-aging performance of the prepared cable composite material. The flame-retardant filler of this invention has urethane bonds grafted onto its surface, which matches the polarity of the EVA vinyl acetate segments, improving the compatibility between the flame-retardant filler and EVA, and further enhancing the flame retardancy of the prepared composite cable material.

The utility model discloses a novel motor casing relates to motor technical field, including the mounting hole on the base of casing body and its bottom, and the mounting hole wall is circumferentially provided with one or more outward extending heat conduction groove, and this heat conduction groove penetrates casing body outer surface and is communicated with the inside of mounting hole. The structure constructs the heat dissipation channel that reaches the outside of casing through the mounting hole area, and the heat blocking problem that the small bolt head contact area, air insulation of traditional motor casing causes is solved. When the bolt and the inner wall of mounting hole contact, heat can diffuse to the external environment along the heat conduction groove, and the local temperature rise of base mounting hole area is reduced, and then material thermal aging and bolt pre -tightening force attenuation are avoided.

The utility model discloses a device for monitoring the alternating thermal aging effect of an atmosphere on a stator bar, and relates to the field of monitoring the insulating capacity of a generator stator bar. The simulation box is a sealed box body; the stator bar is installed in the simulation box. The atmosphere control module is used for controlling the oxygen concentration in the simulation box; the temperature control module is used for controlling the environment temperature in the simulation box; the macroscopic deformation monitoring module is used for acquiring macroscopic deformation of the stator bar; the internal stress monitoring module is used for acquiring internal stress of the stator bar; and the master controller is connected with each module. The generator stator bar insulation alternating thermal aging monitoring device can solve the problem that in the prior art, the full periodicity of a generator stator bar operating under the oxygen concentration condition of a high altitude environment cannot be effectively monitored under the insulation alternating thermal aging effect.

This application provides a method for thermogravimetric analysis (TGA) of resin-based composite materials for aero-engine components, belonging to the field of composite material testing technology. The method includes: extracting the operating state points of the aero-engine components; simplifying the operating state points; determining statistical results of the component's operating temperature and operating time for the thermogravimetric analysis based on the simplified operating state points; conducting a preliminary thermogravimetric analysis based on the statistical results of the component's operating temperature and operating time; using the preliminary thermogravimetric analysis results as a benchmark, determining the thermogravimetric trend and the direction for conducting thermogravimetric analysis using a temperature gradient; determining the temperature threshold for thermogravimetric analysis based on the temperature gradient thermogravimetric analysis results; calculating the cumulative thermogravimetric rate of the composite material used in the aero-engine components over the entire engine lifespan by calculating the thermogravimetric rate at each operating temperature above the cumulative temperature threshold; and accelerating the thermal aging of a new test piece to the cumulative thermogravimetric rate to obtain performance loss results.

The invention belongs to the technical field of safety evaluation of service materials, and particularly relates to a microscopic rapid evaluation method for a long-time thermal service state of a nuclear power pressure vessel material, which comprises the following steps of: 1, selecting a pressure vessel micro-area material in a certain service state; 2, a specific corrosive liquid is selected for corrosion for a certain time, and a state monitoring sample piece is obtained; step 3, the microscopic morphology of the state monitoring sample piece is shot through a microscope; 4, counting the percentage composition of the corrosion area; and 5, evaluating the thermal service state of the material according to the linear relationship between the percentage composition of the corrosion area and the thermal aging time. According to the microscopic rapid evaluation method for the long-time thermal service state of the nuclear power pressure vessel material, thermal aging degradation damage of the pressure vessel material is presented through an over-corrosion method, rapid evaluation of the thermal aging state can be achieved only by obtaining a local monitoring material, and the microscopic rapid evaluation method still has a good prediction effect on long-time thermal service equipment.

The invention relates to a polypropylene composite material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The polypropylene composite material disclosed by the invention is prepared from the following components in parts by weight: 22 to 84 parts of polypropylene resin, 4 to 11 parts of elastomer, 9 to 21 parts of talcum powder, 0.15 to 2.5 parts of thermal aging aid and 0.18 to 1.2 parts of light aging aid, the thermal aging auxiliary agent comprises an antioxidant, a neutralizer and porous silicon dioxide A; the mass ratio of the antioxidant to the neutralizer to the porous silicon dioxide A is (0.5-5): (0.5-3): 1; the light aging auxiliary agent comprises a light stabilizer and porous silicon dioxide B; the mass ratio of the light stabilizer to the porous silicon dioxide B is (0.5-3): 1. The polypropylene composite material with excellent heat aging resistance and light aging resistance is obtained by compounding polypropylene and a specific auxiliary agent.

This invention discloses a method for dynamic modeling of the temperature field and prediction of overheating risk in cable connectors, relating to the field of electrical equipment condition monitoring and thermal management technology. The method includes constructing the connector's geometric domain and establishing a fully coupled electro-magnetic-thermal-mechanical initial value model containing Lorentz force correction terms and eddy current loss heat source terms; jointly assembling the Lorentz force and eddy current loss terms to form a magneto-thermal coupling correction matrix, calculating the equivalent heat source field of a strong magnetic field; solving the temperature field and updating the conductivity and permeability distributions in reverse, forming a bidirectional coupled iterative loop until a converged temperature field is output; extracting hot spot trajectories and temperature gradient vector fields based on the converged temperature field, inputting them into the thermal aging kinetic model of the insulation material to generate a multidimensional indicator surface for overheating risk, determining the risk level and outputting a warning signal. This invention improves the accuracy of connector temperature field prediction and the reliability of overheating risk warning under strong magnetic field environments through bidirectional coupled iterative correction and fully coupled modeling.

The invention belongs to the technical field of high polymer material modification, and discloses a heat-aging-resistant high-performance PVDF pipe fitting material and a preparation method thereof.The material is composed of a PVDF matrix, a two-dimensional nanosheet layer subjected to surface compatibility treatment, a light cross-linking system, a compatilizer, an antioxidant and a processing aid; the preparation method comprises the following steps: carrying out surface compatibility treatment on a two-dimensional nanosheet layer; carrying out melt blending granulation on a part of the PVDF matrix, the two-dimensional nanosheet layer and a compatilizer to prepare nanosheet master batches; carrying out melt blending on the residual PVDF matrix, the master batch, the antioxidant and the processing aid, adding the light crosslinking system in the later stage, and carrying out vacuum devolatilization; after filtering, extruding and granulating to obtain the PVDF pipe fitting material. The material is suitable for PVDF (Polyvinylidene Fluoride) pipes and pipe fittings for conveying high-temperature corrosive media.

The invention discloses a composite material capable of improving the thermal conductivity of LDPE and a preparation method of the composite material. The composite material is prepared from MOFS particles, NiS2 particles and LDPE. The preparation work of the composite material is carried out by adopting a melt blending principle and utilizing a rheometer, and the whole preparation process is simple in principle, easy to understand and convenient to operate. An infrared spectrum characterization characteristic test is carried out on the prepared nano composite material, it is found that after LDPE is doped with MOFs particles, NiS2 particles and MOFs / NiS2 composite particles with different concentrations, the molecular chain structure of the whole composite material is not changed, it is found through a heat conduction performance test that the heat conduction performance of the NiS2 / MOFs / LDPE composite material is better than that of pure LDPE on the basis that the dielectric performance of the NiS2 / MOFs / LDPE composite material is not affected, and the heat conduction performance of the NiS2 / MOFs / LDPE composite material is better than that of the pure LDPE. The thermal aging rate of the insulating material is slower, the service life is longer, and the loss of LDPE can be reduced to a certain extent.

The present application relates to a kind of high flexibility hydrogen gas barrier resistant bio-based polyamide composition and its preparation method, the composition of the present application is by the synergistic matching of bio-based raw materials and specific components, different from the raw materials and process route of prior art.The composition has high flexibility and low tensile modulus under the premise of guaranteeing excellent melt strength, perfect adaptation complex forming process such as extrusion blow molding and 3D blow molding.By introducing special toughening agent and composite thermal stabilizing system, product shows excellent anti delamination performance and heat aging resistance under high temperature of 150 DEG C and dynamic mechanical stress, also has excellent resistance to calcium chloride corrosion ability.Especially prominent, the composition can still maintain high impact toughness under extremely cold environment of-40 DEG C, and has excellent barrier property to hydrogen, solves the technical contradiction of traditional material in new energy automobile hydrogen storage system, improves the use safety and life under extreme working condition.

The invention belongs to the technical field of high polymer materials, and discloses a PP / PA composite material for an automobile front-end module and a preparation method of the PP / PA composite material. Tackifying resin and fumed silica are introduced into a PP and PA resin system to improve polarity, so that PP / PA and long glass fibers are fully infiltrated and bonded during impregnation, the glass fibers are better wrapped, tight combination is formed, the strength of the composite material is improved, and floating fibers are prevented. And the organic-inorganic hybrid heat-resistant agent is introduced, so that the heat aging resistance of the composite material is comprehensively enhanced. The ethylene-butyl acrylate copolymer is introduced, and a butyl acrylate tough chain segment is utilized, so that the glass fiber is prevented from being excessively shorn during injection molding processing, and good rigidity, strength and impact toughness are ensured. The obtained PP / PA composite material is used for the front-end module of the automobile, can provide enough tensile strength, impact toughness and high temperature resistance in the aspects of impact and vibration bearing and heat dissipation, and promotes wide application of the material in the front-end module of the lightweight automobile.

The utility model relates to a base for a quartz crystal resonator, which comprises a shell and a base, a first heat conducting sheet is arranged in the middle of the bottom of the shell, and the bottom of the shell is connected with the upper part of the base; a second heat conduction piece is arranged in the middle of the upper portion of the base and makes contact with the first heat conduction piece, the interior of the base is hollow, and a heat exchange device is arranged on the base. The shell and the base are provided with the first heat-conducting fin and the second heat-conducting fin which are high in heat-conducting property, high temperature in the shell is transmitted to the base through the heat-conducting fins, low temperature in the base is transmitted to the shell, heat exchange is carried out, the shell is cooled, the temperature in the shell is effectively reduced, and the service life of the shell is prolonged. And the problem of thermal aging acceleration of the crystal wafer caused by overheating is reduced, so that the reliability and stability of the resonator are improved, meanwhile, the problem of clock out-of-step caused by temperature change is reduced, and accurate operation of the system is ensured.

The invention discloses a method for evaluating the aging performance of flame-retardant insulating oil, and relates to the technical field of performance evaluation of insulating materials of power equipment, and the method comprises the following steps: S1, sample preparation; s2, a sequential coupling aging test: sequentially performing an accelerated thermal aging test and a disruptive discharge aging test on the flame-retardant insulating oil sample; s3, performance parameter testing and characteristic rule identification: testing a flash point, a breakdown voltage, a dielectric loss factor tan delta and an acid value of the sample at different stages of the sequential coupling aging test; analyzing an evolution rule of a flash point along with thermal aging time, change characteristics of a breakdown voltage in thermal aging and breakdown discharge aging processes, and change trends of a dielectric loss factor and an acid value; and S4, comprehensive performance and service life evaluation. According to the invention, through a sequential coupling aging test, a complex working condition of a thermal-electric stress synergistic effect in the transformer is comprehensively simulated, and the limitation of a traditional single aging mode is overcome.

The invention relates to the technical field of polyimide slurry preparation, in particular to polyimide composite heat insulation slurry and a preparation method thereof. The problems that a traditional heat insulation material is high in haze and poor in heat aging resistance are solved. The slurry comprises modified hollow mesoporous silicon oxide, a passivated infrared blocking agent and an alicyclic polyimide matrix, precise matching with the refractive index of a matrix is achieved through microsphere surface phenyl modification, and interface scattering is eliminated. An organic-inorganic structure is formed by using surface amino groups to participate in in-situ polymerization, so that microsphere agglomeration and floating are prevented; and in cooperation with dense silicon resin passivation on the surfaces of the nanoparticles, excellent heat insulation performance and extremely high optical transmittance are achieved at the same time on the premise that fluorine is not contained completely, and the fluorine-free heat-insulating film is suitable for high-end display panels such as organic light-emitting diodes and micro light-emitting diodes.

The invention discloses an accelerated life test method for expanded polytetrafluoroethylene for aviation, and belongs to the technical field of aircraft maintenance and detection. Comprising the following steps: mounting a sample, and performing at least one accelerated working condition simulation test including repeated compression, medium soaking, heat-moisture treatment, salt spray corrosion, solar radiation and the like; performing thermal aging on the test sample subjected to the simulation test at different temperatures; testing the mechanical property of the sample after thermal aging, and determining a critical value of the mechanical property by taking sealing failure as a judgment standard; and calculating the time when the performance reaches the critical value at different temperatures, and drawing an Amenius diagram to obtain the service life. According to the test method, complex working conditions can be accurately simulated, the service life of the material is efficiently obtained through scientific testing and calculation, a basis is provided for safe replacement of expanded polytetrafluoroethylene for aviation, the problems that a traditional method is difficult to adapt to actual scenes and service life prediction is not accurate are solved, and the reliability of an aircraft sealing system is guaranteed.

The utility model discloses enameled round copper wire high-temperature aging test equipment, which relates to the technical field of enameled wire high-temperature aging test and comprises a thermal aging test box, a base plate is rotatably connected in the thermal aging test box, a bearing plate is movably clamped on the upper surface of the base plate, and two connecting columns for fixing a sample are movably connected on the upper surface of the bearing plate. The butterfly-shaped screw is rotated upwards to be separated from the clamping connection with a group of limiting grooves formed in the base plate, the limiting is opened, the connecting column can move at the moment, the connecting column moves to apply different degrees of tensile force to the sample, so that the tensile strength change of the enameled wire in a thermal aging environment is detected, and the detection accuracy is improved. The bearing disc, the connecting column, the butterfly screw and the like are all made of high-temperature-resistant materials, the decline condition of the mechanical property of the enameled wire can be evaluated by measuring the maximum tensile force which can be borne by the enameled wire under different aging time and temperature conditions, and an important basis is provided for judging the service life of the materials.

The invention discloses a transformer thermal aging simulation device in a laboratory and a test method, and relates to the field of insulating oil. The simulation device comprises a dual-temperature aging unit, an oil change unit, a detection unit and a control unit. The double-temperature aging unit comprises an aging tank, a heating rod and a wire, and the wire is connected with a current transformer; the oil change unit comprises an oil storage tank, the aging tank is provided with an oil injection pipe opening and an oil outlet pipe opening, and the oil storage tank is connected with the oil injection pipe opening. The simulation device is provided with a heating rod and current transformer double-temperature control system, a gradient temperature area existing in actual transformer operation can be simulated, meanwhile, the whole oil change process of the aging test is in a closed space, the oil change operation is high in efficiency and simple and convenient, a large amount of water can be prevented from being introduced to interfere a test result, and the test efficiency is improved. The method has important significance for accurately evaluating the thermal aging performance of the transformer insulation system.

The invention relates to the field of cables, and particularly discloses a long-life nuclear-radiation-resistant low-smoke flame-retardant marine cable sheath material as well as a preparation method and application thereof. The invention relates to a long-life nuclear-radiation-resistant low-smoke flame-retardant marine cable sheath material. Used raw materials comprise the following components: EVA, EBA, EEA, linear low-density polyethylene, low-density polyethylene, maleic anhydride graft, color master batches, an inorganic flame retardant, an organosilicon flame retardant, carbon nanotubes, a surface treating agent, a crosslinking sensitizer, a compound multi-element antioxidant, a light stabilizer, an ultraviolet absorber and a lubricant. The preparation method comprises the following steps: premixing and mixing the raw materials to obtain the sheath material. The sheath material disclosed by the invention can be used for preparing a sheath layer of a cable, has good thermal stability, flame retardance and mechanical properties, is relatively high in tensile strength, tearing strength and elongation at break, and also has excellent performance in a thermal aging test and a mineral oil resistance test.

The utility model belongs to the technical field of aging test boxes, and particularly relates to a ventilation type thermal aging test box. Comprising a box body, and an inner shell and an outer shell are arranged in the box body; the two circulating air ducts are arranged, the left circulating air duct and the right circulating air duct are respectively a left cavity and a right cavity divided by an inner cavity between the inner shell and the outer shell, a plurality of electric heating wires are arranged in the circulating air ducts, and a circulating fan is mounted at one end of each circulating air duct; the air inlet mesh and the air outlet mesh are arranged at the bottom and the top of the inner shell respectively and used for being communicated with the air inlet end and the air outlet end of the circulating air duct; the rotating net disc is rotationally installed at the bottom of the inner shell, the driving shaft end of the rotating net disc is connected with the output end of a driving motor, and the driving motor is installed in the box body; the aging temperature with uniform distribution can be provided for the to-be-tested product, the heating rate is high, and the aging test period of the product is shortened.

The application discloses a kind of on-line evaluation methods of remaining service life of insulation bus duct, belong to the technical field of electric power equipment.The method comprises: obtaining the reference thermal life parameters of insulating material, including activation energy and frequency factor;Real-time temperature data in operation is obtained according to sampling period;Characteristic life value under current temperature is calculated based on the temperature data using Arrhenius equation, and the ratio of sampling period length and characteristic life value is taken as the thermal aging loss increment of the period;Loss increment is accumulated to historical cumulative thermal aging loss total value;Whether the cumulative value reaches the life termination threshold is judged, and the remaining service life evaluation result is calculated and output when not reached.The application combines thermal aging model with on-line temperature monitoring, to realize dynamic evaluation under variable temperature condition in the form of discrete time sampling and loss accumulation, solves the problem that offline evaluation cannot reflect actual operation condition cumulative aging, algorithm is simple, deployment cost is low, and is suitable for bus duct on-line monitoring.

The invention discloses a polyamide composite material which comprises the following components in parts by weight: 60-80 parts of polyamide resin; 1.3 to 3.3 parts of a hindered phenol antioxidant; 0.5 to 0.9 part of a copper salt antioxidant; 1.2 to 2.0 parts of a phosphite ester antioxidant; 10 to 30 parts of reinforcing fiber; and 3-5 parts of a silane coupling agent. By selecting the compound antioxidant, a full-temperature-range thermal aging resistant effect can be achieved, and particularly, performance reduction caused by degradation of the glass fiber impregnating compound is improved.

The invention discloses a heat-aging-resistant polypropylene composite material and a preparation method thereof in the field of composite materials. The heat-aging-resistant polypropylene composite material comprises the following components in parts by weight: 120-130 parts of polypropylene, 0.2-0.3 part of a modified nucleating agent, 0.15-0.25 part of a bio-based antioxidant and 0.12-0.16 part of nano-zinc oxide. The invention provides a heat-aging-resistant polypropylene composite material and a preparation method thereof, in order to solve the problem of poor heat-aging-resistant performance of polypropylene, the crystal structure of the polypropylene is changed by preparing a modified nucleating agent, the heat-aging-resistant performance of the polypropylene is improved, meanwhile, a bio-based antioxidant is prepared, and the heat-aging-resistant performance of the polypropylene is improved. The heat aging resistance of the polypropylene is further improved.

The invention discloses a hot melt adhesive as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. The hot melt adhesive provided by the invention is prepared from the following raw materials: PA66 resin, low-molecular-weight polyamide, a thermoplastic elastomer, a hydrophobic nanofiller, a tackifier, a flame retardant, a coupling agent and the like. The high-performance PA66-based hot melt adhesive, which is finally obtained through refined formula design, introduction of a plurality of functional aids and reasonable adjustment of the proportion of all components, has the following advantages: the high-performance PA66-based hot melt adhesive has high temperature resistance and can be used for a long time at 150-200 DEG C, and the performance retention rate after thermal aging is greater than or equal to 90%; the moisture absorption is ultralow, and the water absorption rate is less than or equal to 0.3% (24 hours, 23 DEG C); the insulating property is high, and the volume resistivity is greater than or equal to 1016 omega.cm; the flame retardance reaches the UL94 V-0 level; the adhesive is wide in base material adaptability, and has excellent bonding strength on metal, ceramic, plastic, composite base materials and the like; low gas release is achieved, and the electronic industry clean room standard is met.

The invention discloses a current-carrying capacity calculation method and system for a high-voltage direct-current submarine cable under a thermal aging condition, relates to the technical field of high-voltage direct-current submarine cables, and aims to solve the problem of misalignment of current-carrying capacity calculation caused by thermal aging of an insulating material after long-term operation of the high-voltage direct-current submarine cable. The method is technically characterized by comprising the following steps: determining a thermal conductivity time-varying attenuation function of the high-voltage direct-current submarine cable material at high temperature based on a first-level dynamic law; and calculating the current-carrying capacity of the submarine cable based on the thermal conductivity time-varying attenuation function. On the basis of experimental study on the long-term aging rule of the XLPE material, a thermal conductivity time-varying function is constructed, and then an accurate calculation method for the steady-state current-carrying capacity of the high-voltage direct-current submarine cable after increasing along with the service time is provided. The invention provides a new method for the capacity planning and design of the high-voltage direct-current submarine cable system and the dynamic evaluation of the current-carrying capacity in the long-term operation and maintenance process.