Simulation Modeling Of Tri-sectional Regenerative Air Heater And Variable Conditions Analysis For Super-critical Boiler System

Our country is at the middle stage of industrialization, a surge in demand for electricity. The current structure of energy production with coal as the main energy consumption structure and thermal power-based, energy loss caused very serious, serious impact on China's ecological environment, sustainable development. At the same time, the special conditions of thermal power units in China often participate in peak shaving, it makes large coal-fired generating units variable working condition and energy control method research imminent.This paper selects the important auxiliary equipment of coal-fired units, takes a 600 MW tri-sectional regenerative air heater as research object. Based on the full analysis of the working principle of the characteristics of the structure, operation mode, divided it into several thermodynamic areas,and established a tri-sectional regenerative air heater mechanism model. Then based on the standard thermal calculation method of two sectional regenerative air heater, established a heat transfer under quasi- steady-state calculation model and given the calculation method. The model was realized by using Matlab/Simulink software package, for off-design condition of operation and verification, and compared with the design value. The experiment shows that the model relative errors of the output parameters are controlled within 1%.The established model of air preheater access to coal-fired generators group analysis platform Cycle-Deck simulation, the boiler system model which is more perfect. According to different working conditions, carried out a detailed simulation, the distribution of the internal thermal parameters of boiler system under variable conditions. The efficiency of the boiler and the coal consumption rate was analyzed, the results show that the design of the model to calculate the value of boiler economic conditions index in good agreement with the actual. For under a single load, the effects of different environmental temperature on the boiler system was simulated. The results showed that within a certain temperature range, the ambient temperature has little effect on the thermodynamic parameters of the boiler system. Finally, using the model for different coal types, varying operating conditions under different loads are simulated in detail. The result shows that coal characteristics influence deeply on boiler system, the steam temperature and reheat steam temperature are lower than what they are should be, and coal consumption is higher.This paper, in order to provide useful technical support for the coal-fired power unit energy saving safety and efficient operation.