Study On Temperature Control Of Water Wall In Supercritical W Flame

With the increasing of high quality coal resources consumption and the reducing of can be used reserves, how to efficiently use the limited coal resources and to improve the current combustion technology to burn the abundant poor quality coal resources has become the technological innovation area in coal industry, thermal power station is a traditional large consumption of coal resources, and the technological innovation is the head one in the whole industry in the period of highly efficiency use of coal resources. Since the last few decades, the power plant unit has continuously promoted in the aspect of sub-critical, supercritical and ultra supercritical pressure units in order to improve the efficiency of the units; while under the existing combustion mode, we constantly explore the new ways of combustion to improve the boiler combustion rate and better to adapt to the current abundant poor quality coal resources. Such as the W flame burning boilers, introduced from foreign technology and constructed in large scale in recent years. W flame boiler has its unique technical advantages and good economic benefits at the aspect of burning anthracite, but as a new developed pulverized coal combustion and with the expansion of boiler pressure parameters and unit scale, it still faces the immature difficulties in combustion control technologies, which limit the W flame boiler’s more economical and safe use. How to ensure W flame boiler operate in the safe and economic condition has great significance.This thesis studies the supercritical W flame boiler’s power changes of boiler water and water wall in the condition of nonuniform combustion heat load. Firstly, through the analysis of the structure of actual units, to divide the water circulation return circuit of boiler water cool wall and to establish the quality equation and the momentum equation to solve the flow of each return circuit; Second, according to the flow characteristics of water wall tube working medium, heat transfer characteristics and pressure characteristics of homogeneous flow model is established and the pressure drop process; through the analysis of mass flow chart under entrance flow and outlet pressure, pressure chart, velocity vector diagram, turbulent dissipation chart and the temperature mixed graphs in pipeline to comprehensively research water wall tube’s hydrodynamic force condition at a specific mass flow rate, in addition, to demonstrate the rationality and the correctness of the simulation results combining the actual cases.Through further analysis of the simulation results, the supercritical W flame boiler hydrodynamic characteristics have been discussed further. This thesis has researched the change condition of each simulation map with the change of parameters in the pipeline fluid disturbance process from double simulation to multiple simulations, which makes it more close to the work conditions for the actual operation process. At the same time, in the process of analysis of the conclusion and expectation, the new suggestion for the deficiency of the experimental simulation and the points needed to be improved have been put forward.