Study On Modeling And Control Strategy For Integrated System Of Micro Gas Turbine And Organic Rankine Cycle

Micro gas turbine is the key technology in the field of energy and power system in twenty-first Century.It is also an important sign to measure the advanced degree of the industrial foundation of a country.The development of micro gas turbine technology has great strategic significance and broad industrialization prospects.A micro gas turbine refers to a super small gas turbine with a power between 25-500kW.The thermal efficiency of a micro gas turbine with a regenerator can reach 20%-30%,but only 14%-20%without the regenerator.Therefore,the existing micro gas turbines are basically equipped with a regenerator.The flue gas temperature of a micro gas turbine is between 200-340℃,and a large amount of heat is wasted with the discharge of the flue gas.With the increasingly severe situation of energy crisis and environmental protection,the recovery and utilization of the waste heat from flue gas have been paid more and more attention.At the same time,improving the thermal efficiency of micro gas turbine is also the main problem that needs to be solved in its own development process.Waste heat utilization of Organic Rankine Cycle has the advantages of simple structure,high efficiency,environmental friendly,and is richly endowed by nature advantages in low grade heat recovery.Based on the principle of "temperature counterparts,cascade utilization",using the method of Organic Rankine Cycle to utilize the waste heat of the micro gas turbine generator is an effective way to improve the power generation efficiency of the micro gas turbine system and recover the waste heat resources.The paper establishes the micro gas turbine waste heat utilization system based on Organic Rankine Cycle,according to the research object,WR100 micro gas turbine generator.The main contents of this paper include the following parts.1.The micro gas turbine generator set and the waste heat utilization based on Organic Rankine Cycle is deeply analyzed and the working principle of the system is expounded.Special research is carried out on the main working parts,thermodynamic cycle process and performance indicators,and the calculation equation of the static process of the system is given,it also provides a basis for establishing the dynamic mathematical model of the system in the future.2.On the basis of relevant knowledge obtained through in-depth analysis,according to the mechanism of the system,in view of the mass conservation equation,thermodynamics equation and energy conservation equation,the mathematical model of a micro gas turbine system is set up through reasonable assumptions according to the design parameters of the WR100 micro gas turbine.Based on the established system model,the simulation of the system is carried out.The simulation results show that the power output of the model can follow the change of the load,and its parameters are reasonable and the results are reliable.3.Considering the random fluctuation of the electric load of a micro gas turbine generator in the actual working process,a generalized predictive controller is designed for the model of the established micro gas turbine.Then,the set value tracking ability test and the anti disturbance ability test are carried out for the micro gas turbine in the regenerative cycle.The simulation results show that all the simulation tests have achieved satisfactory control results under the action of the controller.Besides,in the contrast test with the traditional PID controller,the generalized predictive controller designed in this paper shows better control performance.It also verifies that the established system model is available.4.In order to effectively recycle the gas waste heat from the micro gas turbine,the paper adopts the flue gas waste heat Organic Rankine Cycle power generation system.A multi-variable neural PID control algorithm based on quadratic performance index is proposed for the multivariate characteristics and variable operating conditions of the Organic Rankine Cyclic power generation system.Simulation results show that the designed controller reflects excellent control quality,and the Organic Rankine Cycle system can effective utilize the waste heat of micro gas turbine’s running process.More important,it can generate more additional power and save fuel consumption to a great extent.