Research On Water Recovery Management Of Renewable Fuel Cell System For Near Space Application

Compared with the traditional lead-acid battery,Ni-Cd battery and other secondary batteries,RFC has high specific energy and power.It's a new type of energy storage battery with board development prospect.In recent years,aircrafts that can achieve long-term flight in the near space are the key research objects of various scientific research institutions and universities in the world.Because of the strict requirements on the mass and volume,it hasn't been applied in engineering at present.Research shows that only the RFC energy storage system with specific energy of 400Wh/kg can meet the requirement.Combined with the solar energy,the system can achieve the energy balance,which make the idea of near space aircraft a reality.For near space aircraft,system energy storage mode determines the endurance of the power plant.As the only circulating medium in the RFC system,and it cannot be replenished during flight,water management scheme has a great significance to the performance of system.According to the power demand of the long-term near space aircraft,this paper uses the hybrid energy of solar renewable fuel cell as the propulsion system scheme of the aircraft,and studied the input parameters calculation,energy distribution,water separation and recovery,and comprehensive heat utilization scheme of the energy storage system,mainly including the following content:Aiming at the coupling problembetween weight and energy in the design process of the hybrid vehicle with solar regenerative fuel cell,based on the principle of energy balance a sinusoidal solar irradiance model is established to decouple the energy equation and weight program in the overall vehicle and power system parameters.The power balance of solar cell and RFC energy storage system are drawn.By analyzing the influence of different electrolyze power configuration scheme on the laying area of solar cell array,according to the research direction of this paper,the design input parameters of RFC energy storage are obtained.According to Faraday's Law and electrochemistry theory,the medium balance parameters of the system are calculated by analyzing the system flow chart of RFC energy storage system,including the relevant parameters such as the production and consumption of hydrogen and oxygen,waste heat and efficiency under the operation conditions of electrolysis conditions of electrolysis an fuel cell.The compression factor is introduced to modify the state equation of ideal gad to accurately calculate the volume of gas storage tank,so as toavoid the increase of pressure difference of hydrogen and oxygen gas after several regeneration cycles,which will affect the normal operation of the system.Through the calculation of the key nodes which carry more water in the system,the parameters of water form,proportion,pressure,temperature and so on are obtained in the energy storage system.Using GUI to develop the calculation softwarein MATLAB.Through the integration and modular design of the energy balance equation and the medium parameter calculation formula of the RFC storage system,an operable interface is made,which is conductive to simplifying the calculation process,improve work efficiency,convenient for the subsequent combination with other modules,and broadenits application range.Through the comparison of a various water-recovery scheme.Mainly researched the non-thermal of the overall gas cylinder.According to the definition of gas moisture content in thermodynamics,this paper analyzes the influencing factors of the water carried by gas,takes the highest water recovery and the lowest condenser power consumption as constraints.Analyzed the cost-effectiveness ratio,which shown that increasing the pressure and reducing the dew point temperature can effectively reduce the water carried by gas.and its feasibility is verified by theoretical and Chem CAD simulation results.Finally,according to the idea of a RFC energy storage system proposed by NASA which it's applied in outer space environment.Analyzed the scheme of hydrogen and oxygen post-treatment by radiation gas cylinder surface.Established the finite element analysis model of integrated regenerative gas dryers/humidifiers,carried out the simulation calculation in ANSYS.The distribution of gas cylinder surface temperature is obtained,and the feasibility of its application to the near space is analyzed.Based on this idea,this paper analyzes the feasibility of its application in outer space and near space environment,put forward the approach of the direction of further research.