Study On Motor-driven And Gas Flow Carrying Mode Powder Fuel Supply Characteristics Of Coal Powder Continuous Rotating Detonation Engine

Powder continuous rotating detonation engine(PRDE)not only has the advantages of high energy density,convenient fuel storage and high safety of the traditional constant pressure combustion powder engine,but also has the advantages of high thermal cycle efficiency of the continuous rotating detonation engine(RDE).It is gradually becoming an important research direction of the current powder engine technology.Powder fuel supply system is an indispensable part of all powder engines.Compared with the traditional constant pressure combustion powder engine,PRDE requires higher demands for powder fuel supply system.In this paper,using coal powder as powder fuel and hydrogen as fluidizing gas,the coal powder fuel supply of coal powder continuous rotating detonation engine is studied by using a selfdesigned motor-driven and gas flow carrying mode powder fuel supply system.When coal powder fuel supply system works,the fluidized bin will form a high-pressure gas environment and change the accumulation state of coal powder in the powder storage bin.Therefore,the coal powder accumulation characteristics in high-pressure gas environment are studied firstly,and then the coal powder supply characteristics of motor-driven and gas flow carrying mode powder fuel supply system are studied.In order to verify and apply the obtained coal powder supply characteristics,the experimental study of coal powder continuous rotating detonation engine was carried out.The above research has important academic and engineering guiding significance for revealing the principle of controlled coal powder fluidization supplication,improving coal powder fluidization transportation technology and studying the working characteristics of coal powder rotating detonation engine.The main research contents and conclusions in this paper are as follows:(1)In this paper,the average and linear density of coal powder under different pressure environments were measured and calculated to study the characteristics of coal powder accumulation under loose loading and pre-compression.Pre-compression is realized by filling high-pressure gas in the fluidization bin to form a high-pressure gas environment,and then releasing the high-pressure gas after the pressure in the fluidization bin is stable.It is found that pre-compression can make coal powder collapse and change the accumulation state of coal powder density increasing linearly with coal powder depth under loose loading.The coal powder accumulation after pre-compression presents a short density growth section and a long density stability section.It is considered that the time uniformity of coal powder fluidization supply can be improved by pre-compression.Further research shows that under the continuous high-pressure gas environment,the accumulation linear density and porosity almost no longer change with the increase of coal powder depth,and the coal powder accumulation presents a relatively uniform state.(2)A set of motor-driven and gas flow carrying mode powder fuel supply system was designed.By using load cell and static pressure sensor to monitor the powder supply mass flow rate and the internal pressure of fluidization bin in real time,the coal powder supply stability,stage,uniformity and flow regulation characteristics were studied.The coal powder supply process of the powder supply system can be divided into initial intake stage,pressure establishment stage,pressure stabilization stage,pressure maintenance stage and pressure drop stage according to the pressure change of the fluidized bin;At the same time,it can be divided into coal powder collapse stage,cavity disappearance stage,stable fluidization stage and residual gas fluidization stage according to the change of the coal powder mass flow rate.The powder supply system presents good coal powder supply stability,space and time uniformity and flow regulation characteristics in the stable fluidization stage.On the other hand,the precompression of coal powder can significantly improve the time uniformity of coal powder supply.(3)Through the motor-driven and gas flow carrying mode powder fuel supply system,the coal powder was supplied to the coal powder continuous rotating detonation engine after precompression,and the operation of coal powder RDE was carried out.In the study,multiple high-frequency pressure sensors and thrust sensors were used to measure the detonation pressure,detonation velocity and thrust of coal powder RDE.It is found that the designed powder supply system has good coal powder supply stability,space and time uniformity and flow regulation characteristics,and all performance indexes meet the requirements of coal powder RDE,and the stable operation of coal powder continuous rotating detonation engine can be realized.