Development Trends of Fire Prevention and Control Measures

3 Current research status of fire science in my country

3.1 Fire dynamics evolution theory ●Instability of basic fire combustion system

To understand the complexity of the fire process The nature of nonlinear phenomena requires that the instability laws of basic fire combustion systems be studied. Through theoretical analysis and experimental research, the critical conditions and mathematical physical models formed by the above laws are established to reveal the multiple equilibrium states and stability change processes of the system's combustion temperature and combustion product amount, which is beneficial to the control of instability phenomena in the combustion system. Research. Research on instability control of basic combustion reaction systems is still in its infancy internationally. Chinese scholars use the control ideas and methods of dynamic system instability and chaos to study appropriate ways to control bifurcation and chaotic phenomena in basic combustion reaction systems. In order to further study the mechanism of complex nonlinear fire dynamics phenomena, we provide Reasonably control these nonlinear fire phenomena and lay a solid theoretical foundation [6].

Flameless oxidation includes room temperature oxidation and smoldering. Many forest fires are also caused by the oxidation of combustible materials in forest land at room temperature. Smoldering is another flameless oxidation phenomenon. Compared with normal temperature oxidation, the temperature of smoldering is generally very high. Smoldering is one of the biggest causes of fires. Fires in industrial combustible mixtures are closely related to explosion phenomena. All these typical disaster-causing processes can be concentrated on their fundamental scientific issue: the study of the mutation mechanism of combustible dynamic systems from a general stable state to a disaster. Fire scientists in my country have begun to study the structure, stability changes and mutation mechanisms of the room temperature deterministic dynamic system solutions of typical combustibles. ●Dynamic evolution of solidified phase fire spread and smoke movement

Study the mechanism and rules of the fire spread process on typical solid and liquid combustible surfaces (oil products, forests, grasslands) in my country, as well as large slopes and canyon terrains and the influence of geographical and meteorological environmental factors on the fire spread process, and establish a fire behavior model under this influence; study the movement rules of fire smoke in open, restricted and network spaces; develop theories and numerical calculations to describe smoke movement method. ●Nonlinear dynamics of special fire behaviors

The complexity of special fire behaviors such as crown fire, flying fire, fire whirlwind, flashover, and backburning stems from its nonlinearity and the differential control of its evolution. The system of equations is also multidimensional and nonlinear [7, 20, 22]. However, the current general numerical methods (discretization methods and methods for solving the algebraic equations obtained by discretization) are linear, thus destroying, covering up and obliterating the nonlinear characteristics of the original control equations and the fire system during the solution process. With the development of nonlinear dynamics, domestic scholars have used certain simplified systems to explore and establish their unique control equations and numerical methods to obtain numerical solutions that can reflect their nonlinear characteristics, but they must have a certain degree of versatility. A lot of work still needs to be done on the nonlinear theoretical model and numerical methods that can reflect its nonlinear characteristics. ●Fire characteristics of large-space public buildings

Study the simulation experiment diagnosis of combustion characteristic parameters of typical materials of large-space public buildings; conduct fire spread characteristics in large-space public building fires and smoke in large-space public building fires Conduct research on air flow characteristics; study computer simulation of fire spread and smoke flow processes in large-space public building fires.

3.2 Research on fire risk assessment technology

Industrially developed countries attach great importance to fire risk analysis and evaluation. In fire monitoring, information analysis, identification principles and methods of fire risk sources, A large amount of money and manpower have been invested in risk assessment technology, fire prevention and control, etc., and some practical methods have been initially formed, which play an important role in fire prevention and control [24].

In terms of operability research and information management of fire risk assessment, system simulation and database technology are widely used abroad, and some feasible and practical methods have been developed. Currently, dozens of fire hazard assessment software packages are successfully used. With the advancement of information processing technology and accident prevention technology, new practical risk assessment software continues to enter the market.

During the "Eighth Five-Year Plan" and the "Ninth Five-Year Plan", our country carried out research on major topics such as "Research on Major Hazard Source Assessment and Macro Control Technology", "Research on Major Industrial Accidents and Special Building Fire Prevention and Control Technology", mainly by* The Ministry of Commerce, the Ministry of Labor, the National Coal Research Institute, Northeastern University, the University of Science and Technology of China and other units [3, 4] were combined and completed collaboratively.

For places with major fire hazards such as petroleum and chemical industries, currently, the fire and explosion index evaluation method of DOW Chemical Company, the MOND method of ICI Company, and the six-stage evaluation method of the Standards Bureau of the Ministry of Labor of Japan are mainly used in China. etc. for fire risk assessment. Northeastern University, the former Labor Protection Research Institute of the Ministry of Labor, the former Wuhan Safety and Environmental Protection Research Institute of the Ministry of Metallurgy, the Labor Protection Research Institute of the Ministry of Chemical Industry and other units systematically introduced and introduced the DOW Chemical Company's fire and fire index evaluation method to the country earlier. It has also conducted risk assessments on the fire, explosion and toxicity risks in the production workshops and oil tank areas of some petroleum and chemical enterprises in my country, and achieved great social and economic benefits. However, compared with the performance of these tasks in developed countries, my country's research on fire risk assessment was carried out relatively late, and management methods are still very backward. The main manifestations are:

1) In our country, major and malignant fires and **Accidents occur frequently and the mechanisms are complex, making it difficult to apply existing foreign methods. For example, in the fire hazard index evaluation method of DOW Chemical Company in the United States, the relevant parameters are formulated based on statistics of fire and fire accidents in developed countries, without taking into account the actual situation of developing countries.

2) The existing fire evaluation and management methods are too simple and crude, making it difficult to effectively conduct correct analysis, evaluation and control of various major fires in our country, and most of these methods can only be applied to current situations. There is a systematic risk assessment, but insufficient consideration is given to the systematic risk assessment in the design stage.

3) Our country has not yet established its own fire accident database. It is difficult to obtain real results by using foreign data to analyze fire hazards in our country, which seriously affects the scientific nature of our country's management and decision-making of fire hazard sources. .

With the enlargement of my country's petroleum and chemical enterprises, the frequent occurrence of forest fires, the extensive use of new building materials, new technologies and new processes, and the intelligence of fire monitoring devices, the development and research of advanced fire evaluation Methods and software have become imperative in fire safety management. From the perspective of prevention and control of fire accidents by governments and enterprises, a systematic, scientific method that can reflect the dangerous status of fire hazard sources and can accurately and effectively evaluate various fire risks is needed.

3.3 Basics of fire prevention and control technology ●Principles and technologies of intelligent fire detection

Study the characteristics of early fires (sound, light, heat), and establish fire identification based on spectrum, acoustics and electromagnetic radiation Model method; study new topological structures of fire safety monitoring systems, and develop intelligent and robust early fire identification principles and technologies

●Principles and methods of clean and efficient fire extinguishing with fine water mist

Research on fine water mist The generation method and the characterization of the characteristics of water mist; study the dynamic process of the interaction between water mist and flame and its impact on smoke transmission; study the impact of additives on the physical and chemical properties of water mist and fire extinguishing efficiency.

Establish a quantitative description of the relationship between water mist characteristic parameters and flame critical extinguishing characteristics, and develop clean and efficient water-based fire extinguishing technology on the basis of experiments ● Flame retardant mechanism and technology

Research on new polyolefin materials with low smoke and low Toxic and halogen-free flame retardant mechanisms; through research on the morphological structure, physical and chemical properties and influencing factors of cured spherical hyperbranched polymer halogen-free flame retardant materials, the rules of radiation curing of new halogen-free flame retardant coating systems can be mastered and flame-retardant mechanism; study the relationship between the flame-retardant mechanism of nano-inorganic flame retardants in polymer composites and their structures; study the establishment and development of new nano-flame-retardant polymer composites 4 Key Laboratory of Fire Science**

The National Key Laboratory of Fire Science (hereinafter referred to as the laboratory) is a top-level research institution in the field of fire science in China. It has a scientific research building, a special fire laboratory building, a second experimental floor, a large space building fire laboratory and an outdoor The experimental site has a total investment of 30 million yuan and a construction area of ??nearly 5,000 square meters. It has designed and developed more than a dozen sets of fire experimental equipment by itself, and used World Bank loans and "211 Project" project funds to purchase a number of advanced instruments and equipment to equip the laboratory, and the computer international communication network has been opened. The overall level of equipment has reached the international advanced level, and some equipment is world-class. The laboratory has become a leading domestic, important Asian and internationally renowned research base and academic exchange center in the basic field of fire science.