| As a new type of positive displacement compressor,scroll compressor is widely used in various industries with its unique advantages.With the introduction of the ’double carbon ’ strategy and the change of market orientation,the scroll compressor is gradually developing towards a more efficient and energy-saving direction.The flow loss generated during the operation of the scroll compressor will seriously affect the performance of the compressor.The largest flow loss occurs when the exhaust is discharged.This is because the shielding of the scroll tooth to the exhaust hole will disturb the exhaust,and the reed valve set at the exhaust hole also has a resistance effect on the exhaust.When the structure design of the exhaust hole and reed valve of the scroll compressor is not good,it will directly affect the working efficiency and service life of the scroll compressor.Therefore,it is particularly important to optimize the design of the exhaust structure and verify the reliability by studying the exhaust flow characteristics of the scroll compressor.In this paper,a three-dimensional flow field simulation model of scroll plate is established by taking the single scroll scroll compressor modified by PMP type line as the research object and combining with the opening method of ex haust hole.The working process of the scroll compressor was simulated by CFD dynamic mesh technology.The transient flow field distribution in the working chamber and the exhaust hole of the scroll compressor under circular and cashew-shaped exhaust holes was obtained respectively.The effects of different exhaust hole structures on the flow characteristics and exhaust flow characteristics in the compression chamber of the scroll compressor were compared.In order to further obtain greater exhaust static pressure,the diffusion optimization design of the cashew-shaped exhaust hole was carried out.The optimal design parameters were found by calculating the static pressure recovery coefficient.The transient simulation of the internal flow of the optimized exhaust hole was carried out.The static pressure,velocit y and vorticity distribution were obtained,and the optimized diffusion effect was verified.In addition,based on the optimized vent structure and the size of the scroll plate,the corresponding reed valve structure is designed.According to the motion characteristics of the valve plate,the stress is analyzed,and the reliability of its operation is studied by structural analysis and simulation.The research show that the cashew-shaped vent has the largest flow area and good opening characteristics within the maximum allowab le opening range of the non-residual volume structure vent after PMP profile correction.Compar ed with the traditional circular vent,it can make the pressure fluctuation in the compression chamber smaller and closer to the theoretical exhaust pressure.It s good opening characteristics can make the gas flow more stable and effectively reduce the exh aust pressure loss.The static pressure recovery coefficient of the optimized cashew-shaped exhaust hole can reach 0.652,and its internal flow is stable.The vo rticity dissipation energy at the wall surface is small and there is no negative velocity and boundary layer separation phenomenon,which proves that the exhaust hole has a good diffusion effect and can effectively improve the exhaust static pressure.The main design parameters affecting the bending stress of the valve plate are the material of the valve plate,the thickness,the pressure difference,the lift of the valve plate and the outlet area of the exhaust hole.Based on the model in this paper,the m aximum deformation of the valve plate with a thickness of 0.2mm conforms to the design lift.Th e stress is less than the maximum allowable stress of the material,and there is no risk of fatigue failure.The valve plate mainly excites the bending vibration in the work,and the valve plate avoids the excitation resonance interval of the scroll compre ssor.and does not produce the resonance failure problem. |
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