Modeling & Simulation And Optimization Design On The Control System Of Organic Fluid Double-cycle Cogeneration

Organic fluid double-cycle cogeneration technology is an energy recovery technology. This technology can generate electricity from residual heat. It not only can greatly ease energy tensions, but also can reduce the consumption of fossil fuels and reduce greenhouse gas emissions, which has enormous economic, social and environmental benefits.The study on organic fluid dual-cycle cogeneration technology, mostly concentrated in the cycle thermodynamic calculation and the comparative analysis of the working medium, and the study of control system is relatively few. Due to imperfect control system, the system operating costs is increasing, which is seriously impediment to the development and promotion of this technology. So the purpose of the study on the organic fluid double-cycle cogeneration technology is getting the control strategy and simulation model of the system, and will be helpful on cogeneration control system's improvement and optimization and commissioning and maintenance in the future.Firstly, learning from the strategy of thermal power Automatic Procedure Start-up/Shut-down (APS) control system and using the hierarchical structure of the pyramid system to make the system divided into several functional groups and device level. In the meanwhile, make the starting procedure divided into several interrelated steps by breakpoint set. Finally, combine all of the steps to get the logic of sequence starting.Secondly, divide system into three independent subsystems, and using the mechanism modeling to study the three subsystems, then we will get the evaporator subsystem condenser subsystem and screw expansion machine system mathematical model. Use the simulation tool SIMULINK to build three simulation models of the subsystem, respectively, and do a simulation study. In allusion to be main disturbance of the evaporator, designed feed forward cascade control strategy, and showed that it is better than the conventional single-loop control. Refer to the evaporator control strategy, carried out the simulation analysis for the conversion of the two conditions which were appeared in the actual operation of the condenser. Got setting method of controls parameters of the condenser, then we can determine solutions of the problem. As to the Screw expanding electrical and mechanical fluid speed system of speed control, carry out the robustness of the system simulation and the unit load rejection test, and execute the regulator disturbance simulation on the power control system.Finally, as to the coupling between the level of the evaporator and the condenser level, the coordination is introduced to the evaporator and the condenser level control system. Propose a coordinated control program and carry out a simulation study. In the rise and fall load conditions, respectively comparative analysis the simulation results of conventional control and coordinated control of the simulation results. The consequence show that compared with conventional control, coordination control's liquid level fluctuation is smaller, adjusted time is less and control quality is better.