Design Theories And Methods Of The Air Preheater Based On The Particle Curtain

In recent years,the technology of flue gas waste heat recovery developed rapidly.The experimental system of particle curtain heat exchanger based on a single-stage heat exchanger unit was designed and built for the background of waste heat recycling of thermal equipment according to the principle of gas-solid mechanism of rapid thermal equilibrium.The theories and methods to design a particle curtain air preheater were structured.The main contents are as follows.(1)The status that the technology of flue gas waste heat was used in industrial area was concluded.The structural characteristics and the working principle of different types of air preheater were compared and analyzed.After including the technology of flue gas waste heat recycling at current stage,and comparing and analyzing the structural characteristics and working principle of diverse air preheater,a particles-curtain heat transfer experiment table was established.A heat transfer mathematical model of the particle curtain heat exchanger was built.The calculations of temperature of the particle-curtain heat exchanger are found out at last.(2)An experimental system,which was used to research the gas-solid two-phase flow characteristics and the gas-solid heat transfer characteristics in the device,was built.The system was consist of heat exchanger unit body,particle feeding system,particle collection system,simulated flue gas system,flow gas reducing system,measurement system and particle circulation loopback system.The experimental system investigation on gas-particle two-phase flow characteristics and heat transfer characteristics in particle curtain heat exchanger was carried out in this experimental system.The impact factor of flow characteristics includes:intake air velocity,particle size,initial thickness of particle curtain,particle mass flow.And the impact factor of heat transfer characteristics included:intake air temperature,intake air velocity,particle size,initial thickness of particle curtain,particle mass flow.(3)A particle curtain air preheater heat transfer calculation model and the methods to design a particle curtain air preheater were built by investigation on gas-solid two-phase flow and heat transfer characteristics in the particle curtain heat exchanger.(4)A particle curtain air preheater of a 20t/h gas-fired boiler was designed through using the above mentioned methods.The structure and size were calculated in the end.