Analysis And Experimental Verification Of Coupled Heat Transfer In Cylinder Liner Structure Of Diesel Engine

In recent years,with the continuous improvement of diesel engine power intensity and the increasingly stringent emission policies,there is more requests on the reliability of diesel engine components.Diesel engine cylinder liner as one of the key component,its reliability largely determines the engine operating cycle,but also have a great impact on engine performance.In addition,the cylinder is a thin-walled part,and its inside is high temperature and high pressure gas,the outside is surrounded by cooling water,under the combined action of this factors will have much thermal stress and thermal deformation.The thermal load and thermal deformation of cylinder liner also directly affect the clearance between the piston and cylinder liner.The larger thermal load and thermal deformation will increase the engine oil consumption,at the same time it will greatly affect the reliability of cylinder liner and diesel engine.Therefore,the research and analysis of the temperature field of the cylinder liner will be helpful to improve the thermal load of the cylinder liner and lay a theoretical foundation for the optimization design of the engine cooling system.So the coupling heat transfer law for the cylinder liner structure of diesel engine and its experimental verification are studied in this paper.Firstly,based on the ZS1100 diesel engine,the finite element analysis was performed to obtain the temperature and stress field distribution of the cylinder liner in the selected working conditions.At the same time,the actual distribution of the temperature field on the inner wall surface of the cylinder liner was tested,and several commonly used temperature measurement methods were compared.It was determined that the thermocouple temperature measurement method was used to test the temperature field of the cylinder sleeve of ZS1100 diesel engine under the selected operating conditions.The method of fixing the thermocouple in the blind bore of the cylinder sleeve wasdetermined,and finally got the temperature field of its wet cylinder under this conditions.Then the changes of the temperature field of the engine cylinder liner under different speed and load of the diesel engine were analyzed.The results showed that the cylinder liner temperature increased with the increase of the diesel engine speed and load,and the temperature of the upper cylinder liner changed more obviously.The error between the measured data and simulation results was within 6%,which verifies the reliability of the research method.Based on the above research methods,a study was conducted on the temperature field of high-strength diesel engine liners.The results show that the error in the simulation and experimental results of the temperature of the inner wall surface of the reinforced diesel engine liner was within 10%,which also provides theoretical basis and technical support for the coupling heat transfer analysis,evaluation and experiment test of the reinforced diesel engine.