车用发动机水冷却系统传热计算及结构设计_车辆工程.pdf

摘要:散热器是汽车水冷发动机冷却系统中不可缺少的重要部件，其作用是将发动机的 水套内冷却液所携带的多余热量经过二次热交换，在外界强制气流的作用下从高温零 件所吸收的热量散发到空气中的热交换装置。做为汽车的动力核心，汽车发动机性能 的好坏，将直接影响汽车的性能。内燃机运转时，与高温燃气相接触的零件受到强烈 的加热，如不加以适当的冷却，会使内燃机过热，充气系数下降，燃烧不正常（爆燃， 早燃等），机油变质或烧损，零件的摩擦和磨损加剧，引起内燃机的动力性，经济性， 可靠性和耐久性全面恶化。但是如果冷却过强，汽油机混合气形成不良，机油被燃油 稀释，发动机工作粗暴散热损失和摩擦损失增加，零件的磨损加剧，也会使内燃机工 作变坏。因此，选择适当的冷却形式和冷却介质也成为设计发动机的关键。

　　　本文是以日产骐达汽车发动机为对象，运用自己所学知识对汽车知识对车用发动 机水冷却系统由已知的参数进行设计计算。如，发动机的耗油率，汽车的标定功率等， 通过传热学原理，机械设计等资料，并根据已有的基本数据，依靠公式来计算出发动 机散热器所需的散热面积，确定其水管尺寸和水管数等散热器参数。

关键词：冷却系统，散热面积，散热器

Abstract:Automotive radiator cooling system water-cooled engine indispensable component, whose role is the engine coolant water kit carried by the excess heat through the second heat exchange, in the outside world under the effect of forced air from the heat absorbed by parts heat to air heat exchange device. Power as the core of the car, car engine performance is good or bad, will directly affect the car's performance. Internal combustion engine running, in contact with the hot gas by the intense heating of parts, if not properly cooled, internal combustion engine will overheat, inflation coefficient decreased, abnormal combustion (deflagration, as early as fuel, etc.), oil deterioration or burning, Part of the friction and wear increased, causing the internal combustion engine power, economy, reliability and durability of overall deterioration. However, if the cooling is too strong, bad gasoline mixture formation, fuel oil has been diluted, the engine heat loss and gross job losses increased friction, increased wear and tear parts, engine work will also deteriorate. Therefore, select the appropriate form and cooling the cooling medium has become the key engine design.

　　　This article is based on the Nissan Tiida car engine was using his own knowledge of the automotive knowledge of the vehicle engine water cooling system designed by the known parameters of calculation. For example, the engine's fuel consumption, auto calibration of power and so on, through the principle of heat transfer, mechanical design, etc., and accordance with the existing basic data, relying on the formula to calculate the area of the engine cooling radiator needed to determine its water size and number of such water radiator parameters.

Keywords: Cooling system, Radiator area, Radiator