Thermodynamics is one of the most important areas of engineering science.It is the science used to explain how most things to work, why some things do not work the way that they were intended, and why other things just cannot possibly work at all.(热力学是工程学最重要的领域之一｡它是一门科学,被用于解释大多数现象如何工作,为什么一些过程不能按指定的方式工作,为什么一些过程根本就不能工作｡)
It is a key part of the science engineers use to design automotive engines, heat pumps, rocker motors, power stations, gas turbines,air conditioners,superconducting transmission lines,solar heating systems,etc.(它是工程师用于设计汽车发动机､热泵､旋转式发动机､发电站､气体涡轮机､空气调节器､超导传输线､太阳能加热系统的关键知识之一｡)
Thermodynamics centers about the notions of energy;the idea that energy is conserved is the first law of thermodynamics. It is the starting point for the science of thermodynamics and for engineering analysis.(热力学是围绕能量的概念展开的｡能量守恒的思想就是热力学第一定律｡热力学第一定律是热力学和工程解析法的起点｡)
A second concept in thermodynamics is entropy; entropy provides a means for determining if a process is possible. Processes which produce entropy are possible; those which destroy entropy are impossible.This idea is the basis for the second law of the rmodynamics.It also provides the basis for an engineering analysis in which one calculates the maximum amount of useful power that can be obtained from a given energy source,or the minimum amount of power input required to do a certain task.(热力学中的第二个概念是熵｡熵提供了确定一个过程是否可能发生的方法｡熵增加的过程是可能的,熵减小的过程是不可能的｡这个思想是热力学第二定律的基础,也为工程解析法提供了基础｡依托工程解析法,人们可以计算出从一给定能量源中可以获得的最大有用能源的量｡也可以计算出一个具体过程工作所需要的最小能量｡)
A clear understanding of the ideas of energy and entropy is essential for one who needs to use thermodynamics in engineering analysis.Scientists are interested in using thermodynamics to predict and relate the properties of matter,engineers are interested in using this data,together with the basic ideas of energy conservation and entropy production,to analyze the behavior of complex technological systems. There is an example of the sort of system of interest to engineers, a large central power station. In this particular plant the energy source is petroleum in one of several forms,or sometimes natural gas,and the function of the plantis to convert as much of this energyas possible to electric energy and to send this energy down the transmission line.(清晰的理解能量和熵的概念对于在工程分析中需应用热力学的人来说是至关重要的｡科学家们对运用热力学预测和叙述物质的性质有着浓厚的兴趣,工程师也热衷于应用热力学,他们利用能量守恒和熵增原理去分析复杂技术系统的动态｡例如,一个大型的发电站｡在这个特殊的装置中,能量来源是以某种形式存在的石油,有时是天然气｡装置的功能是尽可能的将这种能量转换成电能,并利用传输线将电能进行传送｡)
Simply expressed,the plant does this by boiling water and using the steam to turn a turbine which turns an electric generator.The simplest such power plants are able to convert only about 25 percent of the fuel energy to electric energy. But this particular plant converts approximately 40 percent it has been ingeniously designed through careful, applicator of the basic principles of thermodynamics to the hundreds of components in the system. The design engineers who made these calculations used data on the properties of steam developed by physical chemists who in turn used experimental measurements in concert with thermodynamic theory to develop the property data.（简单的说,该装置的作用就是使水沸腾,然后运用蒸汽推动驱动发电机的涡轮机运转｡这种最简单的装置只能将 25%的燃料能量转换为电能｡但是独特一点的该装置能量转化率能达到 40%｡该装置被精心的设计,将热力学的基本定律运用到了系统中数百的部件中｡设计工程师运用了蒸汽的物性数据,蒸汽热物性数据是由物理化学家通过实验测量的方法获得,他是同利用热力学理论获得的热物性数据是一致的｡）
Plants presently being studied could convert as much as 55 percent of the fuel energy to electric energy,if they in deed per form as predicted by thermodynamic analysis（目前正在研制的该装置其发电转换效率能达到 55%,如果他们的动态能达到依据热力学分析的那样的话｡)
