汽车发动机散热器的设计

车辆工程专业毕业论文，论文编号:JX876  论文字数:17157.页数:30

摘  要
 冷却系统是发动机的重要组成部分，对发动机的动力性、经济性和可靠性有很大影响。随着发动机转速和功率的不断提高，对冷却系统的要求越来越高，因而对发动机冷却系统的设计与研究也愈来愈深入。在保证足够散热能力和强度的前提下，高效率低能耗成为冷却系统未来发展的必然趋势。
 散热器是冷却系统的核心部件，散热器的结构是影响其散热能力的重要因素，散热效果的好坏对整个冷却系统有很大影响。本文从理论上分析了提高散热器散热性能的途径，并通过实验对管带式散热器结构对散热性能的影响进行了对比研究。
 冷却水管的布置对散热能力有很大影响，在其他结构参数相同的情况下，冷却水管数量对散热器性能有较大影响，但风阻也大幅增大冷却水管排数多于3排时，散热量并没有随散热总面积的增大而大幅增加，效果一般，但风阻增加也不明显。
 冷却系统的设计与匹配直接影响发动机的性能。本设计对某发动机冷却系统匹配了散热器和冷却风扇，进行了设计计算和校核计算，并对冷却系统进行了结构优化。
 
关键词：冷却系统，冷却风扇，优化设计，散热器性能，匹配计算
 
Abstract
 The cooling system is an important part of engine, it has strong influences on the power, economy and dependability of engine. With increasing in speed and power of engine, the demand to cooling system is higher, so the design and research on the cooling system of engine is also becoming more and more advanced. Under the precondition that the necessary trend that the cooling efficiency is higher and the energy consumption is lower.
 The radiator is the core part of cooling system, its structure is an important influent factor of heat transfer ability, and the quality of the radiator has very great influence on the whole cooling system. This article has analyzed the available ways to improve the radiator efficiency in theory, and has the contrast research on the influence between structure of the tube and corrugated fin radiator and the radiation’s performance through experiment. The arrangement of cooling water pipe is strong influence on heat transfer ability, in a situation that other structure parameter is the same, the quantity of cooling water pipe will have great influence on the performance of the radiator, but the air resistance increases by vast scale also. When cooling water pipe is more than 3 platoon, the heat transfer capacity not as so vast as the increase of the whole area of heat transfer of radiator, the result of heat transfer is transfer is general, but the increases of air resistance is not obvious.
 The design and matching of cooling system affects the performance of engine directly. In this article, the radiator and the cooling fan has been matched for cooling system of one kind of remodeling vehicles, and the designing calculation has been done and the computation has been checked up, and the structure of the cooling system has been optimizing designed.
 
Key words: cooling system , cooling fan ,optimization design, radiator performance ,matching computation
目  录
摘要i
ABSTRACT.ii
目 录.iii
第一章  绪论1
 1.1前言.1
 1.2发动机冷却系统概况.2
    1.2.1水冷型冷却系2
    1.2.2水循环系统2
 1.3国内外发动机冷却系统研究现状及发展趋势.3
第二章  冷却系统散热器的计算5
 2.1 热量计算5
    2.1.1发动机发热量的计算6
    2.1.2发动机散向冷却系的热量估算6
 2.2散热器的设计计算6
 2.2.1散热器的最大散热能力6
    2.2.2散热介质的温度7
    2.2.3散热器散热面积的计算7
    2.2.4散热器的各部分参数8
 2.3本章小结.9
第三章 散热系统其他部分的计算10
 3.1水泵的设计计算.10
 3.2 风扇的设计计算12
 3.3 节温器的选择13
 3.4 水箱14
 3.5 本章小结14
第四章 发动机冷却系统校核与结构优化15
 4.1发动机冷却系统设计计算.15
 4.2发动机冷却系统校核计算.19
 4.3冷却系统结构优化.21
 4.4  本章小结.24
第五章  总  结.25
参考文献.26
致 谢27