Study On Gas-liquid Mixing Characteristics And Experimental Equipment Of Compressed Air Foam System

Compressed air foam system is a modern fire extinguishing system widely used in fire rescue.The hybrid system,core of the compressed air foam system,consists primarily of air supply system,water supply system,and foam supply system.At present,there are few researches related to hybrid systems,and the mixing process lacks corresponding theoretical guidance.This thesis studies and develops CAFS hybrid systems with high efficiency of fire extinguishing,which has important academic research value and engineering significance.In this thesis,the PID control system based on particle swarm optimization is used to develop a high-precision and low-delay compressed air foam experimental platform.The straight pipe layout scheme is adopted on the platform,which is decided by the actual situation of the vehicle.The matching design of key components is based on engineering requirements On this basis,the platform is experimentally studied to analyze the factors affecting foam performance,and the effects of inlet pressure,flow and area changes on the mixing effect,and the changes in gas-hydraulic pressure generated during this process are discussed.The foam properties were studied and the relationship between foam properties and mixing effects was analyzed to provide a theoretical basis for parameter matching of the experimental platform.The mixing process is analyzed based on CFD simulation technology.Taking T-type mixer with T-tube and built-in baffle as the research object.The Fluent mixed model with Luo model in the nested group equilibrium equation is simulated to display the gas-liquid mixing process and study the pressure,velocity and particle size in the tube during this progress.And the gas-liquid mixing characteristics are also revealed.The CAFS platform with static mixer is studied experimentally to analyze the effect of inlet pressure,flow rate and area changes on foam performance.Compared with T-tube,the performance of the foam with the T-type mixer with built-in baffle used in gas-liquid mixing process is also anaylized.In this thesis,the gas-liquid mixing characteristics and laws were studied.It provides technical reference for the development of CAFS hybrid system with high fireextinguishing performance,which has important engineering significance.