汽车起重机液压系统热平衡的仿真与实验研究

发布时间：2018-04-03 16:56

本文选题：汽车起重机　切入点：液压系统　出处：《吉林大学》2011年硕士论文

【摘要】：液压传动技术是汽车起重机传动和控制的关键基础技术,能量在液压系统中进行传递时不可避免的存在损失,这部分能量绝大部分转化为热量传递到液压系统中,导致油温的升高。油温过高会严重影响起重机的工作效率、作业性能,缩短起重机的使用寿命,如何合理控制液压系统的热平衡点关系到汽车起重机的工作效率、使用可靠性,以及起重机生产企业的市场竞争力。传统的热平衡设计计算涉及到液压系统各节点的功率损失、压力损失等,是对功能性设计的补充,其计算方法复杂、误差较大,不能满足有关热平衡的精确设计要求。本文通过对汽车起重机使用工况的研究,分析得出卷扬和回转是汽车起重机最主要的产热工况,确定了以卷扬和回转构成的起重机循环工况,并对循环工况下的液压系统产热原因进行了详细的分析。为简化液压系统热平衡的计算方法,提高计算精度,根据汽车起重机循环工况下的能量传递情况,提出并推导了基于能量守恒的热平衡计算方法,建立了数学模型,利用该数学模型针对某型号汽车起重机液压系统的产散热情况进行了计算。为进一步确定关键元部件对热平衡情况的影响,选用AMESim仿真软件,建立了起重机的热液压模型,对模型中部分参数进行优化,对比油液温升的结果,说明了各参数对热平衡性能的影响,并提出了改进建议。为验证计算结果和仿真结论,进行了大量的实验,确定了液压系统的主要产热和散热元部件,并对元部件的产热和散热效率进行了评估。在评估三联泵的工作效率时,提出并推导了泵和马达总效率的热力学测定法。最后,拟定了起重机的改进方案,并进行了实车改进,通过实验证明,改进方案效果明显。
[Abstract]:Hydraulic transmission technology is the key basic technology for transmission and control of truck crane. The loss of energy in hydraulic system is inevitable, and most of the energy is transferred to hydraulic system.Cause the oil temperature to rise.If the oil temperature is too high, it will seriously affect the working efficiency of the crane, the working performance, and shorten the service life of the crane. How to control the heat balance point of the hydraulic system reasonably relates to the working efficiency and the reliability of the truck crane.As well as crane production enterprises market competitiveness.The traditional calculation of heat balance design involves the power loss and pressure loss of each node of hydraulic system, which is a supplement to the functional design. The calculation method is complex and the error is large, which can not meet the requirements of accurate design of heat balance.Through the study of the working conditions of the truck crane, it is concluded that the hoisting and turning are the main heat producing conditions of the truck crane, and the circulating condition of the crane is determined, which is composed of the hoisting and the turning.The causes of heat production in hydraulic system under circulating condition are analyzed in detail.In order to simplify the calculation method of heat balance of hydraulic system and improve the calculation accuracy, according to the energy transfer under the circulating condition of truck crane, the heat balance calculation method based on energy conservation is proposed and deduced, and the mathematical model is established.The mathematical model is used to calculate the heat dissipation of the hydraulic system of a certain type of truck crane.In order to further determine the influence of key components on the thermal balance, the thermal hydraulic model of crane was established by using AMESim simulation software, some parameters of the model were optimized, and the results of oil temperature rise were compared.The influence of various parameters on the thermal equilibrium performance is explained, and suggestions for improvement are put forward.In order to verify the results of calculation and simulation, a large number of experiments were carried out to determine the main heat production and heat dissipation components of the hydraulic system, and the heat production and heat dissipation efficiency of the components were evaluated.A thermodynamic method for measuring the total efficiency of the pump and motor is proposed and deduced when evaluating the working efficiency of the triple pump.Finally, the improvement scheme of crane is worked out, and the actual vehicle improvement is carried out. The experimental results show that the effect of the improved scheme is obvious.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH213.6

【引证文献】