Study On Hydraulic Expansion Soft Sealing Structure And Its Deformation Of Air Conditioning Heat Exchanger

In the hydraulic expansion process of air conditioning heat exchanger,the reliability of seal directly determines the quality of products.In the factory production conditions,the frequent insertion and pulling out of tube and liquid filling head will damage the seal ring,which shorten its service life,and frequent replacement of the seal ring will reduce the production efficiency.Moreover,when the tube is hydraulically expanded,thenozzle will shrink axially due to the deformation of other tube sections,which affects the length of the tube.Therefore,in order to improve the sealing reliability and service life of the soft seal of the hydraulic expansion of the air conditioning radiator,and reduce the axial shrinkage of the heat dissipation copper tube during the hydraulic expansion as much as possible,relevant research has been done.Therefore,the main research contents of this topic are as follows.(1)Compare and analyze the soft sealing materials of the hydraulic expansion of the pipe,so that the seals have excellent sealing performance and service life;(2)Analyze the existing various sealing structures,and then optimize the sealing structure or propose anew type of sealing structure;(3)Study the deformation of the soft seals in the process of hydraulic expansion,according to these deformation laws,to provide a basis for further optimizing the sealing structure;(4)Evaluate the service performance of thenew sealing structure in the hydraulic expansion connection.Therefore,relevant research has been done from the following aspects.Firstly,the sealing ring is designed from two aspects: the analysis and selection of soft sealing materials and the design of reasonable sealing structure.According to the parameters and experimental requirements of the sealing ring,the test device is designed,and it is tested by reliability test,life test and expansion test.Then the whole action process of the sealing ring is simulated by Abaqus software,the sealing process and failure form of the sealing ring are observed,and the sealing ring is improved according to the simulation results.The performance of the improved sealing ring is tested again.The results show that:(1)the developed outer semicircular sealing ring can seal the tube after compression.The sealing effect of the middle part of the sealing ring in contact with the tube is the best,and it decreases continuously from top to bottom;(2)When the compression ratio of semicircular seal ring reaches 15%,it can seal 16 MPa liquid pressure,and the compression ratio can reach up to 25%,which can seal 40 MPa liquid pressure.The service life of the sealing ring is more than 500 times;When used in hydraulic expansion,the axial shrinkage of the tube is less than 1.2%,and the difference between the axial shrinkage of the two tube ends isno more than 0.5%,which indicates that the shrinkage is uniform;(3)Co MPared with the outer semicircular seal ring,the circular seal ring can effectively improve the material distribution on the inner diameter side of the compressed seal ring,make it more uniform,effectively increase the application range of preload when compressing the seal ring,and is more suitable for factory production;(4)Co MPared with the outer semicircular seal ring,the axial shrinkage of the circular seal ring has the same performance.