Experiments And Research On Fine Water Mist System

As the increase of high buildings by year, the requirement for the fire protection of the electric machine inside these buildings and the corporation is becoming higher. Previously, fire in the oil house, chemical plants and machinery spaces are extinguished by halogen-based fire suppressing agents. But in 1974 scientists found that the halogen-alkyl compound is the main factor of those can lead to the Ozone cavity. Thus, many countries including China have tried to find the a high-efficiency and clean fire extinguishing agents instead of the former one. Currently there are 5 kinds of alternative applied in China: FM-200, Carbon dioxide, Intergen, Aerosol and SDE. In this thesis I will get a result of that fine water mist system is the most useful and applicable alternative of Halon fire extinguishing agent via analysis economic and technology on five alternatives.At present, there are two methods in the research of fine water mist system: one is to set up a mathematics model, simulate the process of the reaction between flame and water mist; another is experiment, analysising the principle of fine water mist and the influence to the efficiency of putting out a fire from all sorts of factors in a intuitionistic way. In this article, I will use the experiment method to determine the influence of the pressure, height and the size of the nozzle to the effect of the fire protection. Comparing with other experiments, mine is more creative in the design of the nozzle, and therefore it provides some information for the research of nozzle all over the world. Through the experiments of several kinds of nozzle, we can get hold of that the drop generated by the centrifugal pressure nozzle performs well in the uniformity and satisfy the request of the fine water mist in size. In the experiment, we determine drop size, effective water flux and spray angle in various conditions, and illustrate the influence of sorts of factors to the effect of fire protection. We can elicit that more pressure, lower height and smaller size of the nozzle is, the better efficiency we can achieve. But in other side, the increase of the pressure will cause a high requirement to the pipe and make the system more complicated and more expensive; the height also need to fit to demand of the build in; too small size will make the nozzle jam, besides the filed of protection for every muzzle is becoming smaller. For the same area, it needs more nozzles and will be more expensive. Hereby we should consider all factors for a special fire state and then we can get the most optimized solution. According to the compare among the effect of fire protection of these nozzles, we conclude that the length of mix cavity has an infection on the effect of fire protection: longer the length of mix cavity is, the better the effect of the fire protection is.I still discusses the design of the fine water mist system. Due to the lack of the standard for the design of the fine water mist system in China, consulting the design of the water mist system, I supply some reference suggestion for the choice of the arguments in the design.