Study On The Mechanism Of Internal Leakage Of Scroll Compressor

Scroll compressor is a new type of displacement fluid machinery,compared with rotary compressor,reciprocating compressor,has simple structure,stable performance of internal work flow,small fluctuation,high efficiency,low noise advantages,has been widely used in power,refrigeration and air conditioning and medicine and other fields.The main components of scroll compressor are static scroll plate,dynamic scroll plate,bracket body,balance iron,crankshaft anti rotation mechanism and so on.The dynamic vortex plate is used for the rotary translational motion and the static scroll disk to be engaged with each other to form a plurality of closed compression chambers to realize the suction,compression and discharge of the gas.Because the cavity being unsteady compressible flow leakage,leakage makes internal flow and performance of the compressor compressor is changed In order to study the effect of variation of working chamber leakage of scroll compressor flow field and flow field,on the basis of analyzing and summarizing the inner leakage model of scroll compressor,was studied by theoretical calculation and numerical simulation method of single scroll compressor working chamber of tangential leakage and radial leakage mechanism.First of all,according to a certain type of scroll compressor,through theoretical analysis and application of MATLAB programming calculation,obtain the geometric parameters and the thermal parameters required for the simulation,and the scroll compressor of six types of internal leakage model characteristics and applicability are analyzed.Second,based on the basic geometric design parameters and thermodynamic parameters of scroll compressor,a combined model of structured and unstructured grids is established.Different numerical simulation methods are used to obtain the influence of the pressure difference,axial clearance and rotating speed on the tangential leakage and the distribution of internal flow field in the working process of the scroll compressor.The influence of mesh quality on the numerical simulation accuracy is analyzed by comparing the structured and unstructured mesh models with different speeds.Third,to study the radial leakage mechanism of axial meshing clearance of scroll compressor.The scroll compressor moving vortex disk affected the overturning2 moment,the static scroll plate which form the axial clearance leakage problem of the wedge angle,based on the theory of gas dynamics,establishes the leakage model of radial wedge plates.The distribution of pressure field,velocity field and temperature field are obtained by numerical simulation.Considering the influence of compressibility and friction loss,the theoretical analysis,numerical simulation and experimental results are compared to verify the accuracy of the model.The research results show that the leakage channel of the working chamber of the scroll compressor is complex.In order to improve the efficiency and reduce the leakage,the factors affecting the working conditions of the compressor should be considered.For the complex flow field distribution law can not be measured directly,through the establishment of a reasonable simulation model,the use of numerical simulation method for analysis.