Research On Water Mist Fire Extinguishing Technology In Enclosed Space

As a good choice to replace Halon to be the fire extinguishing agent,water mist fire extinguishing technology has many advantages such as high efficiency, adaptability,security,environmental protection,which has been accepted by the world. In the event of fire,it must generate and gather a lot of toxic gases and heat in short time in an enclosed space such as aircraft cabin, submarine cabin and spacecraft cabin which cannot conduct air convection and heat exchange with the outside. It is harmful to both personnel and equipment. Therefore, it has great significance to carry out research of water mist fire extinguishing technology and its application of fire extinguishing system in enclosed spaces.On the basis of the existing technology, this paper carries out research on the technology of water mist fire extinguishing in an enclosed space.A system of water mist fire extinguishing in an enclosed space includes five parts which have been built according to the experimental requirements. The five parts are: power source module, mist spraying module, water mist diameter test module, fire test module and data acquisition and processing module, which are independent and also interrelated.The system provides a basis of hardware for the experimental study reliably and effectively.The design of nozzles has been improved using the method of optimal design based on previous research,which can effectively extinguish many types of fire with good performance.This paper also focuses on the effectiveness and mechanism of water mist suppressing early electric fires caused by cables and electrical equipments. Results can be attained from experiments that water mist works effectively on electric fires. The efficiency of fire suppression goes higher with smaller water mist diameter. The water mist is safe to electrical equipments as they can work well in the field of water mist with good performance of insulation.Accordingly, solid fires caused by daily necessities such as paper, cloth, are considered in this paper. The results show that water mist can effectively suppress solid fires in the enclosed spaces. Combustion products contain more carbon monoxide in the process of fire suppression as water mist has asphyctic effect on the core of fire combustion zone which burns inadequately without enough oxygen. The fire suppression using water mist has relatively low efficiency in the state of hidden fire.