Study On Structure And Pressure Loss For Independent Cooling Fan Drive Hydraulic Integrated Circuit

With the enactment of the energy saving and emission reduction regulations of engine and the rationalization of engine cooling demand,the construction machinery begun to popularize the independent cooling system of the hydraulic fan drive control in China.But in the face of the hydraulic control independent cooling system has a high energy consumption and difficult layout,as well as the future development trend of the vehicles available space is becoming smaller,fan drive hydraulic integrated circuit(HIC)is required to reduce the pressure loss,reduce the volume and improve the power density.In view of pressure loss and high volume two points,the causes and effects of pressure loss in different structures are analyzed,and the simulation analysis and experimental research are carried out on typical channel and HIC based on pressure field,velocity field and temperature field.The main contents of the thesis are as follows:(1)Introduced the research background of this subject,the significance and development trend of the construction machinery engine independent cooling,analyses the current two more outstanding problems of high pressure loss and high volume in fan drive HIC.The paper stated the domestic and foreign research situation about pressure loss and put forward the fan drive HIC of research methods to reduce the pressure loss and heat.(2)Based on the basic theory of fluid mechanics,the friction pressure loss and local pressure loss are analyzed in detail.The paper introduces the influence of the processing technology,internal structure and pressure loss of manifold in hydraulic system.Introduced the computational fluid dynamics simulation software and its settings.(3)Through the study of 3D modeling and simulation for the four types of right-angle channel structure,?-type structure,Z-type structure,spatial 90°-type structure,right angle bend and U-type bend,analyzed the oil pressure loss,flow velocity and temperature distribution and change rule in different channel.(4)Through simulation and analysis of the pressure field,velocity field and temperature field of the before improved fan drive HIC.In view of the existing problems of the before improved fan drive HIC,the improved method was proposed and the pressure field,velocity field and temperature field of the improved fan drive HIC were simulated.The geometric parameters and simulation results of the HIC before and after improvement are compared.(5)Took bench test and engineering prototype test for fan drive HICs before and after the improvement.Including the bench test to test pressure loss for the HICs before and after improvement in different flow rate.The engineering prototype test to test pressure loss in different flow and oil temperature rise in unit time for fan drive HICs before and after improvement.The heat balance test was carried out by adding the improved HIC to verify the service performance of the improved fan drive HIC in high temperature environmentThis paper provides a theoretical basis for the improved of fan drive HIC through the simulation analysis of the typical channel and manifold.Through bench test and engineering prototype test,it is proved that the improved fan drive HIC has achieved the purpose of reducing pressure loss,reducing volume and improving performance.