Research On The Thermal Characteristics Of Oil Storage Unit In Small Hydraulic Pumping Station

With the improvement of modern science and technology,the application of hydraulic transmission technology with high precision and high efficiency in the field of engineering machinery,mining machinery,metallurgical machinery and so on has become more and more extensive.Hydraulic transmission technology can also be combined with electrical,control,information and other technologies,which completes the complex work of machinery to meet the actual demands of social production.Therefore,the performance requirement of hydraulic system and components are increasingly high.However,temperature has always been one of the important factors that limit the working efficiency of hydraulic system and the service life of components,and the thermal balance of hydraulic transmission system has become the focus of attention.From the perspective of heat dissipation of the hydraulic transmission system,it can be seen by the relevant literatures that the oil storage unit,as one of the important components of hydraulic transmission system,is the largest heat dissipation element in the whole system.Its performance directly affects the dynamic characteristics and thermal balance state of hydraulic system.Thus,it is of great significance to explore the relationship between the structure and thermal characteristics of the oil storage unit for hydraulic system.Based on the above reasons,this paper takes the oil storage unit as the research object,and discusses the influence of the length of the return pipeline,the height of the baffle hole and the position of the baffle on the flow and heat transfer of the internal hydraulic oil.The major work of this paper is as follows:(1)Combined with the domestic and foreign research status of thermal characteristics of hydraulic system and different components,the important role of the oil storage unit on the heat dissipation of hydraulic system is expounded,meanwhile,the content and meaning of the study on thermal characteristics of the oil storage unit in this paper are illustrated.(2)The multiphase flow model used in hydraulic oil flow of the oil storage unit and the heat transfer mechanism followed in heat exchange with the outside environment are explained in detail,and the method of the whole-field modeling is put forward to study the thermal characteristics of the oil storage unit.(3)First of all,the whole model of 500×350×240mm3 oil storage unit is established.Secondly,the transient thermo-fluid-solid coupling process of the oil storage unit is simulated by using the fluid heat transfer simulation software Fluent.Then,the simulation results are post-processed.Next,the cloud pictures of temperature distribution at different sections and the temperature-time curves at different particles are obtained.Finally,the effects of three structural variables on the thermal characteristics of the oil storage unit are clarified.Under the same conditions of other variables,what the structure of the oil storage unit is in the following three states: when the length of the main return pipeline is 190 mm,and the height of the baffle hole is 30 mm,the baffle is in the middle position as well.In these three structures,the hydraulic oil temperature is relatively low at the lower port of the outlet pipeline.(4)A suitable hydraulic transmission system and the temperature measurement system are designed,and a complete test platform is assembled.By using the method of controlling variables,the three structures variables of the oil storage unit are changed,and some experiments are carried out.Finally,the temperature-time curves under different variables are obtained.When the length of the main return pipeline is 220 mm,the height of the baffle hole is 33 mm,and the baffle is located in the middle position,namely,the structure of the oil storage unit is in this state,and the oil storage unit consumes the least time to reach the limit state of starting the heat exchange with the external environment.The temperature rise of the lower port of the outlet pipeline is the lowest,and the impact on the hydraulic system is the smallest.