| The Regional Integrated Energy System(RIES)has great advantages in integrating new energy and multi-energy coordination,which is in line with the current trend of energy green and low-carbon development.In the integrated energy system,the micro-gas turbine combined heat and power unit is used as a supplement for insufficient new energy output due to its clean,flexible and efficient characteristics.However,in the traditional micro-gas turbine cogeneration,the exhaust smoke of the micro-gas turbine is often directly discharged into the atmosphere due to the low temperature.Aiming at this part of the wasted low-temperature waste heat resources,this paper designs an Organic Rankine Cycle(ORC)power generation system,and puts the designed ORC system in RIES for overall optimization scheduling research.The paper first carried out the optimization design of the structural parameters of the ORC system.Because the heat source of the ORC system in this paper is the smoke exhaust parameters of the micro-gas turbine cogeneration system,the cogeneration system was constructed based on the overall energy and quality conservation of the system.Model work,through modeling to obtain the flue gas temperature and flow parameters of the system under different power generation and heating conditions,which are used as the heat source parameters of the ORC system.Then,a steady-state optimization model of the ORC system was established,and the net output power,output power per unit heat exchange area and thermal efficiency of the ORC were used as evaluation indicators to optimize the heat exchange area of the ORC evaporator and condenser.In the optimization algorithm,a new type of bionic algorithm is selected: Manta Ray Foraging Optimization(MRFO),and compared with the classic particle swarm optimization algorithm.The results show that the optimization effect of MRFO is significantly better.Furthermore,the ORC is modeled by sub-modules,and for the evaporator with complex dynamic characteristics in ORC,mathematical modeling based on the moving boundary layer is carried out to explore its dynamic characteristics.Furthermore,according to the coupling relationship between the modules and the parameters,the dynamic models of the ORC system are obtained by combining the modules.Because the outlet pressure of the evaporator of the ORC system is very important to the power generation efficiency and safety of the ORC system,an active disturbance rejection controller is designed for the outlet pressure of the evaporator in the article.The simulation results show that the controller has achieved good results.The paper establishes a nonlinear scheduling model that takes into account the ORC microgas turbine cogeneration system,photovoltaic,fuel cell,battery and heat pump in RIES to express the relationship between fuel cost,system operation and maintenance cost and output power.The RIES coupling model of multi-energy forms and multi-devices is established with a bus-bar structure.With the optimal economic index,the OPTI toolbox is used to solve the mixed-integer nonlinear programming model.The simulation results show that the optimization results are reasonable.On this basis,the ORC layered control strategy design is carried out with the scheduled MGT-CHP smoke exhaust parameters.The upper layer optimizes the optimal evaporator outlet pressure setting value according to the heat source flow and temperature.In order to speed up the optimization solution,An improved MRFO-2 algorithm is proposed in the article;the lower layer is the control layer using ADRC,which is responsible for tracking control of the set value.The simulation results of scheduling and control show that the hierarchical control strategy enables the ORC system to always maintain the optimal operating point under variable working conditions and heat source conditions,and realizes safe and efficient operation under optimized scheduling instructions through active disturbance rejection tracking control. |
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