The Dehumidification System For Main Cable Of Suspension Bridge Based On Electromagnetic Heating

In the suspension bridge design theory, the main cable design life is equal to the bridge design life, which is not considered replacement. It’s commitment to the full superstructure of all static and dynamic loads. Therefore, the main cable is essential to the suspension which is the suspension bridge’s lifeline. The main cable dehumidification problem is one of the major problems that all of countries are dedicated to solve in the world. The method of drying air injection dehumidification system that was submitted by Japan had been applied in certain occasions. The dehumidification system took on measures of overall the main cable. It was a large system, which cost huge investment and high operating costs. It is difficult to promote the system all over the world, and only a few bridges had taken use of the system in China. The air humidity inside the main cable is the major factor that the main cable wire be corroded. It will have an effect on its carrying capacity and using life if severe corrosion. Therefore, the article proposes a dehumidification system for main cable based on electromagnetic induction heating.First of all, the basis of dehumidification will be described in this paper. Then the solutions of the induction heating power supply system were compared. What’s more, the overall structure of the electromagnetic induction heating device and the analysis of its work operation were given. In addition, the electromagnetic induction heating principle applies to the main cable dehumidification was described. The main indicators of the device was given, and the dehumidifier main components(including rectifier circuit, filter circuit, IGBT selection, isolated half-bridge resonant circuit and trigger circuit) parameters selected were carried out a detailed analysis. Finally, the main cable suspension bridge had been taken as experimental subject, launched the experiment by using of electromagnetic induction heating and dehumidification. The experiment was carried out in the experimental center in Liuzhou OVM Machinery Co., Ltd., which was used of 15 k W,20 k W, 25 k W, 30 k W and so on, at the main cable to heat. The experimental data were derived by a large number of experiment showed that in the same heating time when the heating power was 30 k W, the main cable dehumidification effect was met the requirement of experiment, and the humidity value of each position of the main cable are controlled in less than 60% RH, achieved the purpose of dehumidification.So far, no one has done experiments related as main cable dehumidification by electromagnetic heating, moreover, not haven applied the electromagnetic heating into the main cable dehumidification. Therefore the dehumidification system for main cable ofsuspension bridge based on electromagnetic heating has some innovative and cutting-edge.Meanwhile, the experiment has some exploratory confirmatory. A lot of experimental steps and experiences derived from trying and verifying by gradual steps. In this study, by selecting appropriate heating power, winding matched suitable coil, and carrying out a large amount of experiment. The experimental results show that the dehumidification system for main cable of suspension bridge based on electromagnetic heating is feasible.Ultimately, it can achieve the purpose of main cable dehumidification.