模块化螺杆膨胀发电机组转速控制模型

Speed Control Modeling of Modular Screw Expander Generation System

为研究基于有机朗肯循环的模块化螺杆膨胀发电机组的动力机转速控制,建立了螺杆膨胀机转子的动态响应模型.对满液式蒸发器建立一种固定边界分段模型,并采用一阶惯性环节对模型进行补偿.针对模块化螺杆膨胀机组无调节阀直接控制进入螺杆机工质流量的特点,提出通过控制热源流体侧调节阀来间接控制螺杆机转速的方法.针对热源流量变化对工质蒸气流量及焓值都会产生影响的情况,分别建立系统的流量通道及焓通道模型.在Matlab中分别建立对应的系统动力机转速控制模型并仿真.仿真结果表明:通过控制热源流体流量来控制动力机转速的控制策略可行;相对于工质焓值,工质蒸气流量在转速调节中起主要作用.通过对转速、热源流量以及比例-积分-微分控制器参数等扰动信号的仿真分析可知,该控制系统具有较强的稳定性.

A dynamic response model of screw expander was established to study the speed control method of the modular screw expander generation system based on the organic Rankine cycle（ORC）.A new method of fixed boundary multisection model was adopted in building the expander model.Because the modular ORC screw expander generation system does not have the steam regulating valve,the engine speed cannot be controlled directly by regulating the steam flow rate.Therefore,an indirectly method for regulating heat fluid flow rate was adopted.When the heat fluid flow rate was regulated,the steam rate and enthalpy changed at the same time.So,two types of physical model was established based on it.A simulation model was established in Matlab and the control model was tested and optimized.The simulation result show that this indirect method to control the speed of the engine is feasible and the steam rate plays a major role in the speed control system.