| The electric cable, as a carrier of transmitted and allocated electric energy, is widelyused. But the aging problem will inevitably come forth for the temperature, moisture andsalinity. Degradation of cable insulation, which is resulted by the age problem, can lead thefaults of shorts, arcing and open circuits. And the fire may be happened for the hightemperature which affected by the faults. So it’s important to study the temperature fieldand infrared testing technology for the judgment of ship cable aging degree according tocharacter of the ship cable. And it’s valuable for the reliability of ship.First, a three-dimensional mathematical heat transfer model has been built according tothe structure of cable. The3D(three dimension) temperature field of cable has beensimulated based on the experiment, and the correctness of model has been proved by theresults of experiment. The results which calculated with different current and circumstancetemperature show that the conductor temperature is highest and the surface temperature islowest; The surface temperature at axial is uniform; The temperature changed obviously atthe beginning0.5hour, and changed little after1.5hours. The condition of cable can’tdetermined by the temperature at the beginning.Second the3D temperature field with the faults of aging and partially aged aresimulated. The simulated results show that the temperature field with the faults of agingchanged little, but the temperature different of surface and conductors changed obviously;when which is partially aged, the surface temperature different increasing, and the highesttemperature and lowest temperature existed at both sides of the aging segment. Variationbetween different parts of cable surface is more and more obvious with the aging degreeincreasing, The partially aging fault of cable can be diagnosed by the infrared inspectionquickly. The temperature affected by operation time of cable, but the distribution oftemperature little. It’s reliable to test the temperature after1hours in order to gained thehigher temperature different of surface.At last, the method of infrared testing and diagnosis have been studied. And the testingmethod of conductor temperature has been studied also. The influence of cable current oncable temperature difference has been studied, and the math expressions have beenresearched through the least squares method under different aging degree. The cableconductor temperature can be simulated quickly by the math expressions based infraredinspection. The infrared diagnosis system of ship cable is studied by the VB and VC. Andwhich is helpful to the operation of naval ship motor. |
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