DT型重型载货汽车冷却系统的设计与优化

发布时间：2018-05-25 06:54

本文选题：重型载货汽车 + 冷却系统　；参考：《太原理工大学》2016年硕士论文

【摘要】：汽车保有量的持续高增长带来了日益严重的能源问题和环境问题。冷却系统作为汽车发动机工作的保障性部件,对发动机的排放、油耗、耐久性等都有直接的影响,而目前我国重型载货汽车冷却系统的总体水平与国外同类车型相比较还有差距,存在冷却效率不足和能耗浪费等现象。为满足日益严苛的油耗、排放法规,提高整车产品的综合技术水平,本文以DT型重型载货汽车为原型车,采用数值模拟和台架试验的方法对冷却系统基本模型展开研究,通过优化其发动机舱内流场、冷却系统结构等,开展了以下工作内容。1)利用CATIA建立了DT型重型载货汽车动力系统三维简化模型,采用ICEM进行前处理,在FLUENT中模拟计算,获得了CFD三维模型。再者,利用GT-SUITE系列软件,根据试验数据建立了六缸增压中冷发动机一维模型及其冷却系统一维模型。通过计算数据传递,得到了一/三维耦合模型,为开展冷却系统研究建立了模型支持。2)利用所建立的一/三维耦合模型,得到了发动机舱内流场,根据机舱流场情况,提出了改进方案,其一,改变风扇结构;其二,优化导流罩深度;其三,对机舱加装挡风板。并且分析比较了三种改进措施对内流场的影响情况,得出结论,其中采用一体式风扇的冷却系统进风效率较普通风扇最大提高了3.08%,采用导流环风扇的散热器进风流量最大增加了6.36%。探讨了导流罩深度对冷却系统进风效率的影响,通过对比发现125mm的导流罩深度可以获得最大的进风流量。而加装挡风板后,流过散热器的空气质量流量有所增加,增加幅度为3.68%。3)开展了发动机试验平台研究,搭建了车用发动机试验台架。该试验平台不仅可用于发动机能量分布的试验研究,还可直接用于开展车辆冷却系统优化匹配方面的研究。并测量出了发动机散热量,为后续冷却系统的试验研究提供了试验基础,拓展了发动机热管理台架试验研究的方法和手段。
[Abstract]:The sustained and high growth of automobile ownership has brought more and more serious energy and environmental problems. The cooling system, as the supporting component of the automobile engine, has a direct impact on the engine emissions, fuel consumption, durability, etc. At present, the overall level of cooling system of heavy duty truck in our country is still far from that of similar vehicles abroad, and there are some phenomena such as insufficient cooling efficiency and waste of energy consumption and so on. In order to meet the increasingly stringent fuel consumption, emission regulations and improve the comprehensive technical level of vehicle products, this paper studies the basic model of cooling system by numerical simulation and bench test with DT heavy truck as prototype vehicle. By optimizing the flow field in the engine cabin and the cooling system structure, the following work contents are carried out. 1) the three-dimensional simplified model of the power system of DT heavy truck is established by using CATIA. The pre-processing is carried out by ICEM, and the calculation is simulated in FLUENT. The CFD 3D model is obtained. Furthermore, the one-dimensional model and cooling system one-dimensional model of six-cylinder turbocharged intercooled engine are established by using GT-SUITE software. One / three dimensional coupling model is obtained by calculating data transfer, and model support. 2) based on the one / three dimensional coupling model established for the research of cooling system, the flow field in the engine cabin is obtained, according to the flow field in the engine room. An improved scheme is proposed, one is to change the structure of the fan, the other is to optimize the depth of the guideway; third, to install a windshield on the engine room. And the influence of three kinds of improvement measures on the internal flow field is analyzed and compared, and the conclusion is drawn. The intake efficiency of cooling system with integrated fan is 3.08 higher than that of common fan, and the inlet flow rate of radiator with guide ring fan is 6.36% higher than that of common fan. The influence of the depth of the guide cover on the air intake efficiency of the cooling system is discussed. It is found that the maximum inlet air flow rate can be obtained by comparing the depth of the air guide cover with that of the 125mm. After installing the baffle, the air mass flow through the radiator is increased, the increase range is 3.68 and the engine test platform is studied, and the vehicle engine test bench is built. The test platform can be used not only for the experimental research of engine energy distribution, but also for the optimization and matching of vehicle cooling system. The engine heat loss is measured, which provides the experimental basis for the subsequent cooling system test and extends the method and means of engine thermal management bench test.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U469.2;U464.138

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