Research On Electric Fire Detection And Prevention And Control Technology In Gas Station

According to the statistics of the National Fire Yearbook in 2012-2015 released Public Security Bureau of Fire Department, the proportion of electrical fires in gas stations accounted its total fire for about 30%, which directly threatens the safe and efficient operation of the gas station. Because of the large electricity load and short cable distance, it is prone to electrical fires. Once the fire occurs, due to the high content of the oil vapor in the air, the combustion is rapid and is easy to explode, and resulting in a large number of casualties and property damage.Therefore, because most of the distribution cables in gas station are laid in the ground, the cable distance is short and the electricity load is large, combining these features in gas station, the over-current protection and fault arc protection technology in the electrical fire prevention and control technology of the gas station are studied emphatically in this paper, the main work and achievements are as follows.First of all, in this paper, the necessity of electrical fire prevention and control studied,then the causes of electrical fires summarized, and we analyzed the research status and development trend of electric fire prevention and control technology, the conclusion that the over-current and fault arcs are the main cause of the electrical fire in the gas station.Secondly, the basic theory and algorithm of electric fire detection and control technology researched in this paper. This paper also studied the basic concepts, causes and harms of over-current protection technology, as well as the shortcomings of the existing over-current protection technology. Aiming at the over-current protection action time is constant, it cannot make the corresponding adjustment with the change of the fault current, so the inverse-time and the definite-time combination of the protection method to improve the over-current protection technology, at the same time, the power device replaced the traditional mechanical switch to improve the speed of protection. For the fault arc protection technology, its concept, causes and detection methods are also studied. Through the establishment and the simulation on the Mayr arc model of the fault arc, the nonlinearity of the current at the time of fault arcing is verified,arc model of the fault arc, the nonlinearity of the current at the time of fault arcing is verified,which is the basis for judging the fault arc, the application of autocorrelation algorithm and Fourier transform algorithm on fault arc detection is studied, and analyzed the respective detection results. Considering synthetically, it is decided to apply the Fourier transform algorithm to the fault arc detection process.Finally, based on the design of the single phase inverse-time over-current electrical fires control device and the fault arc electrical fires control device, the related test and protection experiments are completed. The experimental results showed that the single phase inverse-time over-current electrical fires control device can detect and control accurately the over-current breakdown, and the measurement results are within the stipulated range of relevant national standards. Fault arc can be measured and protected effectively by the Fault arc electrical fires control device, measurement error of related parameters is less than 3mA, error of protection action setting value does not exceed 0.1% and measurement error of protection action time is not more than 50ms.The design of the single phase inverse-time over-current electrical fires control device and the fault arc electrical fires control device had been applied to the electrical fire detection and control system at North Fourth Ring PetroChina Gas Station in Henan Zhengzhou, this system is running well, network communication is reliable, it had successfully eliminated an electrical fire accident, and ensured the safe operation of the gas station, with very practical engineering value.