摘要由于艇用喷水推进装置对主机的转速具有较高的要求，而车用柴油机恰能很 好的满足高转速的特点。但车用柴油机的冷却系统大多为风冷式，很好的利用了 汽车行驶时的迎风，并且主机前段装有轴带风扇用以冷却高温淡水以及空气散热 器。与之相比，舰艇机舱内多为密闭空间，一般首选海水作为冷却介质，采用水 冷式换热系统。84808

本文主要是以某厂生产的 SY4L88 型柴油机为例，将该柴油机改装在小型快 艇上，并对该增压柴油机的冷却系统由“风冷”改装为“水冷”（拆除轴带风扇， 加装海水泵及中冷器等)[1]。合理设计出中冷器的结构尺寸，做出热力计算与压 降校核。在换热效率保证的前提下，优化其结构达到减小压降，缩小尺寸的目的。 主要内容包括以下几个部分：

1、对 SY4L88 型柴油主机的冷却系统进行分析，根据所给出的该型柴油机的 主要技术参数及性能指标，设计管翅式与盘环式两种不同结构的中冷器方案。

2、分别对两种类型的换热器进行热力计算与校核计算，给出详细的结构与 尺寸参数。对比两种方案的优缺点，选择最佳方案，并作出总结。

3、利用 Pro/E5。0 建模软件，建立该换热器的三维模型。

毕业论文关键词： 柴油机；中冷器 ；换热系数；压降；水冷

Abstract Because the water jet propulsion unit of the boat has a high demand for the speed of the engine, and the diesel engine is very good to meet the characteristics of high speed。 However, most of the cooling system of the diesel engine is air cooling, it is good to use the wind when the car is running, and the front end of the main shaft is equipped with a fan to cool the high temperature water and air heat sink。 In contrast, the ship cabin is more confined space, the general preferred sea water as the cooling medium, the use of water cooling system。

The main purpose of this paper is to a plant for the production of SY4L88 type diesel engine as an example, the Diesel Engine Refitted in small boats, and of the turbocharged diesel engine cooling system by the "air" converted to "water" (dismantling the shaft with a fan, installation of water pump and cooler)。 Reasonable design of the structure size of the cooler, make the thermal calculation and pressure drop check。 Under the premise of the heat transfer efficiency, the structure can be optimized to reduce the pressure drop and the purpose of reducing the size。

The main content includes the following parts:

1、The cooling system of SY4L88 diesel engine is analyzed。 According to the main technical parameters and performance indexes of the diesel engine, the design of the tube fin and ring type two kinds of different structure of the cooling system。

2、Through 2 types of heat exchanger for thermal calculation and check    calculation

respectively , it must give the detailed structure and size parameters。 Compare the advantages and disadvantages of the two schemes, choose the best plan, and make a summary。

3、Using Pro/E5。0 modeling software to establish the three-dimensional model of the

heat exchanger。

Key words:diesel engine; air cooler; heat transfer coefficient; pressure drop; water cooling system

目 录

第一章 绪论 1

1。1 研究背景及意义 1

1。2 国内外柴油机热交换器的研究现状 2

1。3 本课题的主要研究内容 4

第二章 柴油机中冷器芯部设计 6