内燃机专业英语翻译

Chapter 1 Enging types and their operation1.1 Introduction and historical perspective1．内燃机的目的是从蕴含在燃料中的化学能中得到机械动力。

The purpose of internal combustion engines is the production of mechanical power from the chemical energy contained in the fuel .2．有别于外部燃烧机器，在内燃机中，能量是在机器内部燃烧或氧化燃料释放出来的。

In internal combustion engines ,as distinct from external combustion engines, this energy is released by burning or oxidizing the fuel inside the engine.3．功的转移，提供了需要的动力输出，发生在工作流体和机器的机械部件之间。

The work transfers which provide the desired power output occur directly between these working fluids and the mechanical components of the engine.4．实际上正是由于燃烧发生在机器做功部件内部才使它们的设计和运行特征从根本上有别于其他类型的机器。

It is the fact that combustion takes places inside the work-producing part of these engines that makes their design and operating characteristics fundamentally different from those of other types of engine.5.水，升成蒸汽，介入到由燃烧燃料产生的燃气和作功活塞膨胀之间。

Water,raised to steam ,was interposed between the combustion gases produced by burning the fuel and the work-producing piston-in-cylinder expander.6.早期面向市场开发的机器是在常压下燃烧煤气空气混合物，燃烧前没有压缩。

The early engines developed for commercial use burned coal-gas air mixtures at atmospheric pressure--there was no compression before combustion.7.煤气和空气在前半个活塞冲程被吸入缸内。

然后用火花点燃工质，压力升高，燃烧的气体在后半个活塞冲程将动力传递给活塞。

循环以排气冲程结束。

Gas and air were drawn into the cylinder during the first half of the stroke.The charge was then ignited with a spark, the pressure increased, and the burned gases then delivered power to the piston for the second half of the stoke. The cycle was completed with an exhaust stroke.8.更成功的改进利用早期向外冲程时工质燃烧导致的压力升高来加速自由活塞和齿条组，由于它的运动将在缸内形成一个真空。

于是大气压推动活塞向内运动，伴随齿条通过一个滚动离合啮合到输出轴上。

A more successful development used the pressure rise resulting from combustion of the fuel-air charge early in the outward stroke to accelerate a free piston and rack assembly so its momentum would generate avacuum in the cylinder.Atmospheric pressure then pushed the piston inward with the rake engaged through a roller clutch to the output shaft.9.这一偶然发现对奥拓四冲程机专利的合法性提出了质疑。

在德国奥拓专利被宣布非法。

This charge discovery cast doubt on the validity of Otto' s own patent for this concept, and in Germany it was declared invalid.10.尽可能大的气缸容积和尽可能小的边界面积；尽可能快的做工速度；尽可能高的膨胀比；膨胀之初尽可能高的压力。

The largest possible cylinder volume with the minimum boundary surface.The greatest possible working speed.The greatest possible expansion ratio. The greatest possible pressure at the beginning of expansion.11.前两个条件保证工质的热量损失达到最小。

第三个条件可认为后燃气体膨胀越大获取的功越多。

第四个条件可认为初始压力越高越有可能产生更大的膨胀，在整个过程中产生更高的压力，两者都会导致更多的功输出。

The first two conditions hold heat losses from the charge to a minimum. The third condition recognizes that the greater the expansion of the postcombustion gases, the greater the work extracted.The fourth condition recognizes that higher initial pressures make greater expansion possible , and give higher pressures throughout the process, both resulting in greater work transfer.12．他的专利利用将液体燃料喷入仅由压缩而加热的空气中触发燃烧使效率高出其他类型内燃机的两倍。

更高的压缩比，不存在爆震或敲缸的现象成为可能。

His concept of initiating combustion by injecting a liquid fuel into air heated solely by compression permitted a doubling of efficiency over other internal combustion engines.Much greater expansion ratios, without detonation or knock were now possible.13.早期产生机械动力的机器燃烧气体。

汽油和原油中的轻质成分在十九世纪末才有，开发出各种化油器来蒸发燃料将其与空气混合。

The earliest engines used for generating mechanical power burned gas. Gasoline, and lighter fractions of crude oil, become available in the late 1800s and various types of carburetors were developed to vaporized the fuel and mix it with air.14.然而由于原油短缺要满足1907至1915年之间五倍汽油的需求，（汽油）从原油中的产出必须提高。

However, a serious crude oil shortage developed, and to meet the fivefold increase in gasoline demand between 1907 and 1915, the yield from crude had to be raised.15开发了热裂解工序，在那里重油在高压下被加热分解为不复杂、更易挥发的化合物。

这些热裂解汽油满足了需求，但它们的高沸点出现寒冷气候的启动问题。

A thermal cracking process was developed whereby heavier oils were heated under pressure and decomposed into less complex more volatile compounds. These thermally cracked gasolines satisfied demands, but their higher boiling point range created cold weather starting problems. 16.Houdry 发现蒸发的油在450至480度的温度下经过活性催化剂可转化为高质量汽油，比热裂解的产出高得多。

这些进步以及其它改进使具有更好抗敲缸性能的燃料可以大量生产。

Houdry found that vaporized oils passed over an activated catalyst at 450 to 480 C were convented to high-quality gasoline in much higher yields than was possible with thermal cracking.These advances, and others, permitted fuels with better and better antiknock properties to be produced in large quantities.17.在过去的三十年中，要改变的新因素变得非常重要并严重影响机器的设计和运行。