Numerical Simulation Of Oil-free Scroll Compressor's Internal Flow Field

In recent years,with the growth of population and resource depletion,the energy and environment problems got the attention of the countries all over the world as a critical issue to the survival and development of human.As a new energy,fuel cell has attracted the attention of government,experts and enterprises with its advantages of environmental protection,cleanliness and high efficiency.It has a wide application prospect in civil and military fields.The gas supply system in fuel cell is used for providing fuel and oxidants to the fuel cell reactor.Improving the efficiency of the gas supply system is important and helpful to improve the energy conversion efficiency of the entire fuel cell system.Compressor is the core component of the gas supply system,occupying the most additional energy consumption.In view of the literature about the internal flow field of the fuel cell compressor is less,an oil-free scroll compressor,made by a company,is the research object of this subject.The internal flow,working in the fuel cell environment,has been analyzed.In this paper,dynamic mesh and computational fluid dynamics(CFD),based on the finite volume method,are used to simulate and analyze the complete two-dimensional flow field.Firstly,the significance of the compressor in gas supply system of fuel cell and the theoretical basis of computational fluid dynamics(CFD)are introduced.Secondly,the creation and assembly of the geometric model of the orbiting and fixed scroll are completed in SolidWorks,based on the working principle and design parameters of the oil-free scroll compressor.The flow field model of the closed compression cavity is established.Some reasonable assumptions are made.The flow field model is simplified to a two-dimensional model.Finally,a high-quality mesh is generated on the flow field model,and the actual motion of the oil-free scroll compressor is simulated by using the dynamic mesh technique in Fluent.The important information,such as the speed field and the pressure field of internal flow and the curve of the relationship between flux and the spindle angle,has been obtained by solving the transient control equation of incompressible flow.This information is useful for further research on the working process of the oil-free scroll compressor and improving its working efficiency and reliability.