自然循环锅炉蒸发区的建模与动态仿真

发布时间：2018-05-29 18:24

本文选题：自然循环锅炉 + 动态仿真　；参考：《大连理工大学》2016年硕士论文

【摘要】：为了满足用户所需负荷的要求,机组调峰、给煤量等操作是无法避免的。然而,在运行操作时电厂人员都是依据实时的动态参数与以往的经验来调节并没有优化的运行方式与目标值,这种运行工况的突变最终会直接影响锅炉蒸发区内部参数的动态特性,其工作条件的恶劣还会产生如结渣、爆管等安全隐患,从而改变其经济性与安全性,故加强锅炉运行管理及调节运行的优化是很有必要的。本文以实际机组CG-220/9.81-M为原型,依据实际工况条件建立小负荷扰动时蒸发系统模型,该模型基于能量与质量的动态平衡并充分考虑蒸发区中热惯性及汽机侧扰动影响,通过利用SIMULINK模块化思想建立其完整的蒸发区一汽机侧的在线计算仿真平台。该仿真平台可在线预测不同工况锅炉机组小负荷扰动下蒸发区内水冷壁有效吸热量、汽包出口蒸汽流量、汽包水位及主蒸汽流量并能够优化调节运行操作或进行离线的仿真分析。首先针对汽包出口蒸汽流量及汽包水位发生小扰动的本质原因进行分析,仿真结果表明：蒸发区有效金属及饱和水的热惯性是影响蒸发区热惯性的主要原因。在小负荷扰动情况下水冷壁有效吸热量直接决定了汽包出口蒸汽流量,其受到给水温度、汽包压力、热惯性及压变速度的影响。而汽包总水位变化与压力、质量、汽泡引起的水位变化有关。其次,为锅炉在调节运行的优化和提高锅炉的运行安全性可提供技术支持,其仿真结果表明：燃料量增加10%时前40s内应控制蒸发区初始压变速度在0.01MPa/s以内；减少燃料量10%前40s内应控制蒸发区初始压变速度在-0.01MPa/s以内。燃料量进行优化调节后,即初始压变速度在-0.01MPa/s以内时,其燃料量应控制在-5%以内；初始压变速度在0.01MPa/s以内时,其燃料量应控制在5%以内。汽机调门开度增加1%前20s内应控制蒸发区初始压变速度在-0.005MPa/s以内,在汽机调门开度减小1%前20s内应控制蒸发区初始压变速度在0.005MPa/s以内。汽机调门开度进行优化调节后,即初始压变速度在-0.005MPa/s以内时,其汽机调门开度应控制在0.32%以内；初始压变速度在0.005MPa/s以内时,其汽机调门开度应控制在-0.32%以内。给水流量增大10%前20s内应控制蒸发区初始压变速度在-0.008MPa/s以内,给水流量减小10%前20s内应控制蒸发区初始压变速度在0.008MPa/s以内。给水扰动量进行优化调节后,即初始压变速度在-0.008MPa/s以内时,其给水流量变化应控制在5%以内；初始压变速度在0.008MPa/s以内时,其给水流量变化应控制在-5%以内。
[Abstract]:In order to meet the requirements of the load required by the user, the operation of unit peak regulation and coal supply can not be avoided. However, in operation, the power plant personnel are adjusted according to the real time dynamic parameters and previous experience, and there is no optimized operation mode and target value. The sudden change of the operation condition will directly affect the boiler evaporation area. It is necessary to strengthen the operation management of the boiler and the optimization of the regulating operation of the boiler, so it is necessary to strengthen the operation management and regulation of the boiler. This paper takes the actual unit CG-220/9.81-M as the prototype, and establishes the evaporation system in small load disturbance according to the actual working conditions. The model, based on the dynamic balance of energy and mass and fully considering the thermal inertia in the evaporation region and the influence of the turbine side disturbance, is used to establish an on-line calculation simulation platform for the whole evaporating area of one steam engine side by using the idea of SIMULINK modularization. The simulation platform can predict the evaporation area under the small load disturbance of different boiler units in different working conditions. The internal water cold wall effectively absorbs heat, the steam flow rate of the drum outlet, the water level of the drum and the main steam flow, and can optimize the operation operation or carry out the off-line simulation analysis. Firstly, the essential reasons for the steam flow rate and the small disturbance of the drum water level are analyzed. The simulation results show that the effective metal and saturated water in the evaporation region are shown. Thermal inertia is the main factor affecting the thermal inertia of the evaporation zone. The effective heat absorption of the water wall under the small load disturbance directly determines the steam flow rate of the drum outlet, which is influenced by the water supply temperature, the pressure of the drum, the thermal inertia and the pressure change speed. The boiler can provide technical support for the optimization of regulating operation and improving the operation safety of the boiler. The simulation results show that the initial pressure change speed of the evaporation zone should be less than 0.01MPa/s in the pre 40s 40s when the fuel amount is increased, and the initial pressure of the evaporation region should be within -0.01MPa/s under the reduction of 10% fuel quantity in 40s. The fuel quantity is superior. The fuel quantity should be controlled within -5% when the initial pressure change speed is within -0.01MPa/s, and the fuel quantity should be controlled within 5% when the initial pressure change speed is within 0.01MPa/s. The initial pressure change speed of the evaporation zone should be within -0.005MPa /s and the opening degree of the turbine is reduced to 1% before the turbine opening degree and the opening degree of the turbine is less than 1% before the opening degree of the turbine and the opening degree of the turbine is reduced to 1% before the 20s internal stress. The initial pressure change speed of the evaporation zone is within 0.005MPa/s. When the opening degree of the turbine is optimized, the opening degree of the turbine should be less than 0.32% when the initial pressure change speed is within -0.005MPa/s. When the initial pressure change speed is within 0.005MPa/s, the opening degree of the turbine should be within -0.32%. The water flow rate increases by 10% 20s. The initial pressure change speed of the evaporation region should be within -0.008MPa/s, and the initial pressure change speed of the evaporation region should be within 0.008MPa/s under the decrease of water flow rate 10% before 20s. When the water supply disturbance is optimized and adjusted, that is, when the initial pressure change speed is within the -0.008MPa/s, the change of the water supply flow should be controlled within 5%; the initial pressure change speed is in the 0.008M. Within Pa/s, the variation of feed water flow should be controlled within -5%.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK221

【参考文献】