某型号汽车起重机发动机高速空载状态热特性分析

为解决某型号汽车起重机散热效果差的问题，研究其液压系统原理，根据主要元件的产热与散热特性，建立了液压系统的热平衡数学模型；基于AMESim软件建立了汽车起重机在发动机高速空载状态下的热液压系统仿真模型，并通过实验对比散热器进出口的温度验证了仿真模型的准确性；分析了发动机高速空载工况下4个泵的压力损失特性.结果表明：2号泵能量损失最大，约38%，由多路阀和中心回转体的能量损失而产生的热量是液压系统的主要产热源；3号泵和4号泵的回油产热也较大，且由于原始设计中回油没有经过冷却处理，导致汽车起重机液压系统整体的散热效果较差.通过将回转系统和控制系统的回油引入散热器，改进后的多路阀各口出口温度降低，油箱的出口温度也明显降低，提高了液压系统的散热效果，改进合理有效，为今后改进汽车起重机液压系统的热管理控制策略提供了指导.

Thermal Characteristics Analysis of a Certain Type of Truck Crane Engine under Highspeed No-load Condition

In order to solve the problem of poor heat dissipation effect of a certain type of truck crane, the principle of its hydraulic system was studied. According to the heat generation and heat dissipation characteristics of the main components, the mathematical model of heat balance of the hydraulic system was established. Based on the software AMESim, a simulation model of the thermal hydraulic system of the truck crane in the no-load state of the engine was established, and the accuracy of the simulation model was verified by comparing the temperature of the radiator inlet and outlet. The pressure loss characteristics of four pumps under high speed no-load condition were analyzed. The results show that the energy loss of No. 2 pump is the largest, about 38%. The heat generated by the energy loss of the multi-way valve and the center rotating body is the main heat source of the hydraulic system. No. 3 pump and No. 4 pump return oil heat production are also large, but because the original design of the return oil is not cooled, resulting in a poor overall heat dissipation effect of the hydraulic system of the truck crane. By introducing the return oil of the rotary system and the control system into the radiator, the improved multi-way valve outlet temperature is reduced, and the outlet temperature of the oil tank is also significantly reduced, which improves the heat dissipation effect of the hydraulic system. The improvement is reasonable and effective, and provides guidance for improving the thermal management and control strategy of the hydraulic system of the truck crane in the future.