有机朗肯余热发电系统控制算法的仿真研究

Study on Simulation of Control Algorithm for Organic Rankine Cycle Power Generation System in Waste Heat

在有机朗肯低温余热发电系统的控制策略研究中,由于热源易受到外界环境的影响,热源温度波动性很大,且热源温度和蒸发器的过热度不可以被直接控制,从而很难使蒸发器过热度维持在一个稳定值。为解决过热度不稳定的难题,提出了模糊PID控制器与SVPWM控制算法相结合的控制策略,详细研究算法原理,确定相关系数,为优化ORC系统提供有效依据。根据算法原理建立数学模型,在蒸发器过热度升高时(工质流量不变),可以根据接收的扰动信号调节电机转速来降低热源流量,从而保证蒸发器过热度恢复稳定。仿真结果表明,运用改进后的系统工作时,热源温度升高后,过热度能在2.5秒内恢复到正常状态,从而实现对蒸发器过热度的稳定控制。

In the paper, the thermal efficiency of Organic Rankine Cycle（ORC） power generation system in low - temperature waste heat was researched. We proposed the control strategy of Fuzzy - PID and SVPWM, carefully re- searched the principle, and detemined correlated coefficients to provide some basis to optimize the system of ORC. According to the principle, we established the mathematical mode. When the evaporator superheat, the system can regulate the speed of the motor according to the disturbing signal to control the flow of the heat source. At last, the e- vaporator superheat became stabilization. The simulation results show that the superheat can become normal state in 2. 5 seconds after raising the heat source temperature, thus the evaporator superheat can be controlled.