蒸汽型高温固体储热系统建模与控制仿真研究

Study on Modeling and Control Simulation of Steam-type High Temperature Solid Heat Storage System

基于MATLAB/simulink软件,建立了包含蓄热体、余热锅炉、风机、水泵等部件的蒸汽型固体储热供热系统仿真模型,分析了恒定入口风量和恒定出口风温模式下的系统动态特性。针对汽包压力升高和用户热负荷降低工况,根据汽包出口阀门开度和风机风量先后调节顺序组成4种控制方法。结果表明:当风量维持5.5 kg/s时,蓄热体出口热风温度及余热锅炉的产汽量均会持续减小,在6 000 s内蓄热体温度由710℃降到了612℃,余热锅炉的产汽量由0.88 kg/s降低到0.67 kg/s。针对压力升高工况,先调节汽包出口阀门开度、后控制风机出口风量,较相反的调节顺序,使系统供汽压力变化的调节时间节省1倍,仅需90 s左右。针对用户热负荷降低工况,先调节汽包出口阀门开度再调节风机出口风量,仅需60 s左右将蒸汽热负荷由0.6 kg/s降到0.4 kg/s,但是汽包压力和汽包水位波动较大,波动值分别为0.08 MPa和0.03 m。

Based on MATLAB/simulink software,a simulation model of a steam-type solid heat storage and heating system was established,which included components such as thermal storage body,waste heat boiler,fan and water pump.The dynamic characteristics of the system were analyzed under constant inlet air volume and constant outlet air temperature modes.Results show that four control methods are formed according to the opening of steam drum outlet valve and the sequence of fan air volume adjustment for the conditions of steam drum pressure rise and user heat load reduction.When the air volume is maintained at 5.5 kg/s,the outlet hot air temperature of the heat storage body and the steam production of the waste heat boiler will continue to decrease.Within 6000 seconds,the temperature of the heat storage body decreases from 710℃to 612℃,and the steam production of the waste heat boiler reduces from 0.88 kg/s to O.67 kg/s.Under the working condition of pressure rise,first adjust the opening of the steam drum outlet valve,and then control the air volume at the fan outlet.Compared with the opposite adjustment sequence,this saves half of the adjustment time of the system's steam supply pressure change,which needs only about 90 seconds.In response to the user's heat load reduction condition,first adjust the opening of the steam drum outlet valve and then adjust the fan outlet air volume.It only takes about 60 seconds to reduce the steam supply heat load from 0.6 kg/s to 0.4 kg/s.However,the steam drum pressure and water level fluctuate greatly,with fluctuation values of 0.08 MPa and 0.03 m,respectively.