Research On Fuel Reforming And Rotating Detonation Pressurized Combustion Technique Of Combustor

It is an important research direction to improvethermal efficiency and reduce emissions of gas turbine in the field of energy and power.While engines based on Brayton cycle have reached a high level of thermodynamic efficiency by steady improvements in components efficiency and increases in pressure ratio and peak temperature,further improvements are becoming increasingly costly to obtain.Pressure losses of isobaric combustion process in typical gas turbine reduced the ability to power;meantime,exhaust heat discharged directly also limited the improvement of cycle efficiency.In this paper,from the point of energy utilization,based on the concept of chemical recuperation,the technology of low-temperature plasma with catalyst synergistic reforming was employed for deeply steam reforming,thus to improve the fuel equivalent heating value,futher to improve the thermal efficiency of advanced cycle;from the point of breaking out the restrictions of traditional Brayton thermodynamic cycle,based on the pressurized characteristic of detonation combustion,the mode of continuous detonation was employed for combustion of reformed gas,to improve work capacity of working fluid and build a new type of combustion thermodynamic processto further improve thermal efficiency.?1?Isothermal reaction test rig was built for catalyst-catalytic fuel steam reforming,and experiments were carried out with self-designed reactor.It was found that DBD catalytic steam reforming was easier to produce higher hydrocarbons.According to this feature,based on experimental data,plasma catalytic reaction mechanism and kinetic models of methane steam reforming was established and developed.The reaction path flow analysis about DBD catalytic methane steam reforming was carried out,and main limitation reaction for product selective of DBD catalytic was found,providing the basis for improving the selectivity of desired products.?2?In order to improve the utilization of waste heat,synergistic reforming factor was designed.Based on the original test rig,from the points of fuel converstion and energy recovery,the effect laws of methane velocity speed,the reactor wall temperature,molar ratio of steam to methane?S/C?,plasma discharge characteristics on reforming characteristics in the different reforming forms were studied systemically.The results showed that the use of parallel synergistic reforming technology had obvious advantages in waste heat recovery and the increase of H₂ selectivity.In the same input power,parallel synergistic reformer can recover more turbine exhaust heat.Moreover,it can recover more heat at a lower temperature,which wasalso beneficial to improve the heat recovery of turbine exhaust in different conditions.?3?Based on a certain type of canannularchamber,from the point of fuel combustion,the reforming characteristics in the different reforming forms werefuther examined and the effect of fuel reforming on isobaric combustion were carried out.In the same inlet enthalpy,flow characteristics and combustion performance were studied of the reformed gas with different components,which further validated total pressure losses caused by the flow resistance and thermal resistance were an inherent defect of isobaric combustor.?4?Based ontwo-dimensional compressible Euler equations,ignoring viscous andthermal diffusion,the rotating detonation flow field with stoichiometricH₂/air was investigated numerically.Using MATLAB and open source CANTERA,detonation cell width was obtained for CH₄/air?CH₄/H₂/air and reformed gas/air,which provided the basis for the choice of the size ofcombustor.Analyses of the macro-structure of detonation flow field and the total pressure distribution of continuously rotating detonation combustor,especially,the average flow field parameters with time were carried out.At last,pressurizedmechanism of detonation combustion was revealed.?5?The effect laws of different inflow total pressures,inflow total temperatures,axial and azimuthal sizes on performance of rotating detonation combustor with stoichiometricCH₄/air were systematically analyzed by numerical simulations.Based on the effect laws,a 2D theoretical prediction model was established and modified to predict the flow structure and properties of continuously rotating detonation combustor.Combined numerical simulation and theoretical analysis,we found the geometric similarity features of rotating detonation pressurized combustor.Theoretical prediction model can exactly predict the flow field parameters and outlet parameters of rotating detonation combustor.?6?Based on a certain type of annular chamber,the effect of fuel reforming on detonation combustion were carried out.With the increase of H₂ content,detonation wave velocity accordingly increased,but detonation wave strength weakened;the pressuried ratio was in the range of 2.5-2.7of the reformed gas with different components,which implies a higher potential power of gas at the exit ofCRDC than that in traditional combustors.?7?Numerical studies on thermodynamic properties along streamlines in rotating detonation combustor were carried out,and based on the concept of"generalized detonation combustion process",a new type of detonation pressurized thermodynamic cycle gas turbine was established.Furthermore,the effect of compressor pressure ratio on cycle thermal efficiency was calculated in new detonation cycle gas turbine and typical pressure cycle gas turbine.The results show that the detonation combustion mode has obvious advantages inimproving thermal efficiency of gas turbine.