Design And Operating Characteristics Of A Novel Isobaric Compressed Air Storage Device In Pneumatic Systems

In recent years,the concept of pneumatic isobaric compressed air storage has been put forward and developed continuously,especially in the research field of compressed air energy storage technology.Research at home and abroad shows that compared with isochoric compressed air storage,isobaric compressed air storage system has the advantages of high system efficiency and high energy density.The problem of low energy efficiency is common in pneumatic systems.The air tank is an indispensable component of the pneumatic system,but the air tank is usually a rigid container.The gas pressure in the tank changes greatly in the process of charging and venting,which greatly increases the energy consumption of the pneumatic system,which is one of the main reasons for the low efficiency of the pneumatic system.Therefore,a new type of isobaric compressed air storage device integrating energy storage technology is proposed in this thesis,and its working characteristics are deeply studied,which provides a new idea for isobaric compressed air storage and step-down energy saving of pneumatic system.The research work of this thesis mainly includes the following aspects:(1)This thesis summarizes and analyzes the existing pneumatic energy-saving technology and constant pressure fluid storage technology,focuses on the pressure distribution of typical pneumatic systems,and puts forward a new idea of reducing pressure and energy saving by realizing the near real-time balance of compressed air flow between gas producing side and gas consuming side through the air storage tank with integrated energy storage technology.(2)The structure of the isobaric compressed air storage device is designed,the mathematical model of the device is established,the profile of the key special-shaped cam structure is designed,and the ideal profile based on energy conservation and the cam profile considering friction effect based on force balance are proposed.(3)Using AMESim platform,the models of isobaric system and isochoric system are established,the pressure stabilizing characteristics of isobaric compressed air storage device are analyzed,and the energy consumption performance of isobaric system and isochoric system under different energy efficiency factors and different compressor control modes are compared.The results show that when the working pressure in the typical system is 0.4MPa,the pressure fluctuation rate of the isobaric compressed air storage device is 2.14%,and the isobaric system can save about 18% energy compared with the isobaric system.(4)The isobaric system and isochoric system are analyzed with the help of the exergy analysis method.Through the accumulated and transient exergy analysis,the root cause of the energy-saving mechanism of the isobaric compressed air storage device is revealed.At the same time,the exergy efficiency of the typical pneumatic system is also described in detail.The exergy efficiency of isobaric system and isobaric system are 45.8% and 52.9%respectively(5)The construction of the test-bed is completed,and the program based on LabVIEW is written for data acquisition and control.The dynamic characteristics of isobaric compressed air storage device under large flow impact condition are experimentally studied,with emphasis on the pressure stabilizing characteristics and temperature characteristics.The results show that the voltage stabilizing performance of the second generation prototype is 15%higher than that of the first generation prototype.