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删除1,849字节 、 2020年8月16日 (日) 23:24
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===Energy, available useful work===
 
===Energy, available useful work===
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能量,<font color = 'red'><s>有用的工作</s></font>'''<font color = '#32CD32'>可用的有用工作available useful work</font>'''
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能量,可用的有用工作
    
{{See also|Exergy}}
 
{{See also|Exergy}}
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An important and revealing idealized special case is to consider applying the Second Law to the scenario of an isolated system (called the total system or universe), made up of two parts: a sub-system of interest, and the sub-system's surroundings. These surroundings are imagined to be so large that they can be considered as an unlimited heat reservoir at temperature T<sub>R</sub> and pressure P<sub>R</sub> so that no matter how much heat is transferred to (or from) the sub-system, the temperature of the surroundings will remain T<sub>R</sub>; and no matter how much the volume of the sub-system expands (or contracts), the pressure of the surroundings will remain P<sub>R</sub>.
 
An important and revealing idealized special case is to consider applying the Second Law to the scenario of an isolated system (called the total system or universe), made up of two parts: a sub-system of interest, and the sub-system's surroundings. These surroundings are imagined to be so large that they can be considered as an unlimited heat reservoir at temperature T<sub>R</sub> and pressure P<sub>R</sub> so that no matter how much heat is transferred to (or from) the sub-system, the temperature of the surroundings will remain T<sub>R</sub>; and no matter how much the volume of the sub-system expands (or contracts), the pressure of the surroundings will remain P<sub>R</sub>.
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考虑将第二定律应用于孤立系统(称为整体系统或宇宙)<font color = 'red'><s>的情形,</s></font>是一个重要<font color = 'red'><s>的、</s></font><font color = 'blue'>而</font>具有启发性的理想情形。该系统由两部分组成:<font color = 'red'>感兴趣的<s></s></font>研究关心的<font color = 'blue'></font>子系统和子系统的周围环境。因为<font color = 'red'><s>环境被想象的</s></font><font color = 'blue'>想象的环境</font>非常<font color = 'red'><s>巨</s></font>大,<font color = 'blue'>以至于</font>它们可以被视为一个温度为 T<sub>R</sub> 且压力为 P<sub>R</sub> 的无限<font color = 'red'><s>蓄热器</s></font><font color = 'blue'>热源</font>,<font color = 'blue'>因此</font>无论有多少热<font color = 'red'><s>量</s></font>被转移到(或来自)子系统,周围的温度将保持T<sub>R</sub>;无论子系统的体积膨胀(或收缩)有多大,周围环境的压力都将保持不变。
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考虑将第二定律应用于孤立系统(称为整体系统或宇宙)是一个重要而具有启发性的理想情形。该系统由两部分组成:研究关心的子系统和子系统的周围环境。因为想象的环境非常大,以至于它们可以被视为一个温度为 T<sub>R</sub> 且压力为 P<sub>R</sub> 的无限热源,因此无论有多少热被转移到(或来自)子系统,周围的温度将保持T<sub>R</sub>;无论子系统的体积膨胀(或收缩)有多大,周围环境的压力都将保持不变。
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Whatever changes to dS and dS<sub>R</sub> occur in the entropies of the sub-system and the surroundings individually, according to the Second Law the entropy S<sub>tot</sub> of the isolated total system must not decrease:
 
Whatever changes to dS and dS<sub>R</sub> occur in the entropies of the sub-system and the surroundings individually, according to the Second Law the entropy S<sub>tot</sub> of the isolated total system must not decrease:
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无论子系统和周围环境<font color = 'red'><s>的 ''dS''和''dS<sub>R</sub>'' 发生</s></font><font color = 'blue'>单独地发生什么熵的变化 ''dS''和dS<sub>R</sub></font>,根据第二定律,孤立总体系统的熵S<sub>tot</sub>不能减小。
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无论子系统和周围环境单独地发生什么熵的变化 ''dS''和dS<sub>R</sub></font>,根据第二定律,孤立总体系统的熵S<sub>tot</sub>不能减小。
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According to the first law of thermodynamics, the change dU in the internal energy of the sub-system is the sum of the heat δq added to the sub-system, less any work δw done by the sub-system, plus any net chemical energy entering the sub-system d ∑μ<sub>iR</sub>N<sub>i</sub>, so that:
 
According to the first law of thermodynamics, the change dU in the internal energy of the sub-system is the sum of the heat δq added to the sub-system, less any work δw done by the sub-system, plus any net chemical energy entering the sub-system d ∑μ<sub>iR</sub>N<sub>i</sub>, so that:
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根据<font color = 'red'><s>能量守恒定律</s></font><font color = 'blue'>热力学第一定律</font>,子系统<font color = 'red'><s>内部能量</s></font><font color = 'blue'>内能</font>的变化 dU 是<font color = 'red'><s>子系统内部能量 q 的总和</s></font>加在子系统上的热δq的和<font color = 'blue'></font>,减去子系统所做的任何功w,再加上进入子系统的任何净化学能 d ∑μ<sub>iR</sub>N<sub>i</sub>,因此
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根据热力学第一定律,子系统内能的变化 dU 是加在子系统上的热δq的和<font color = 'blue'></font>,减去子系统所做的任何功w,再加上进入子系统的任何净化学能 d ∑μ<sub>iR</sub>N<sub>i</sub>,因此
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where μ<sub>iR</sub> are the chemical potentials of chemical species in the external surroundings.
 
where μ<sub>iR</sub> are the chemical potentials of chemical species in the external surroundings.
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其中μ<sub>iR</sub>是外部环境中<font color = 'red'><s>化学物类</s></font>'''<font color = '#ff8000'>化学形态 chemical species</font>'''的化学势。
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其中μ<sub>iR</sub>是外部环境中'''<font color = '#ff8000'>化学形态 chemical species</font>'''的化学势。
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Now the heat leaving the reservoir and entering the sub-system is
 
Now the heat leaving the reservoir and entering the sub-system is
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现在热<font color = 'red'><s>量</s></font>离开<font color = 'red'><s>储存器</s></font><font color = 'blue'>热源</font>进入子系统是
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现在热量离开热源进入子系统是
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It is useful to separate the work δw done by the subsystem into the useful work δw<sub>u</sub> that can be done by the sub-system, over and beyond the work p<sub>R</sub> dV done merely by the sub-system expanding against the surrounding external pressure, giving the following relation for the useful work (exergy) that can be done:
 
It is useful to separate the work δw done by the subsystem into the useful work δw<sub>u</sub> that can be done by the sub-system, over and beyond the work p<sub>R</sub> dV done merely by the sub-system expanding against the surrounding external pressure, giving the following relation for the useful work (exergy) that can be done:
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将子系统所做的功δw划分为子系统可以完成的有用功δw<sub>u</sub> ,除了子系统在周围外部压力下膨胀所做的功p<sub>R</sub> dV外,<font color = 'red'><s>还可以</s></font>给出以下可用功(<font color = 'red'><s>放射本能</s></font>'''<font color = 'ff8000'>有用能 exergy</font>''')关系式:
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将子系统所做的功δw划分为子系统可以完成的有用功δw<sub>u</sub> ,除了子系统在周围外部压力下膨胀所做的功p<sub>R</sub> dV外,给出以下可用功('''<font color = 'ff8000'>有用能 exergy</font>''')关系式:
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It is convenient to define the right-hand-side as the exact derivative of a thermodynamic potential, called the availability or exergy E of the subsystem,
 
It is convenient to define the right-hand-side as the exact derivative of a thermodynamic potential, called the availability or exergy E of the subsystem,
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为方便起见,可以把右边定义为热力学势的精确导数,称为子系统的'''<font color = 'ff8000'>可用性 Availability </font>'''或<font color = 'red'><s>放射本能E</s></font>'''<font color = 'ff8000'>有用能 exergy</font>'''
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为方便起见,可以把右边定义为热力学势的精确导数,称为子系统的'''<font color = 'ff8000'>可用性 Availability </font>'''或'''<font color = 'ff8000'>有用能 exergy</font>'''
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i.e. the change in the subsystem's exergy plus the useful work done by the subsystem (or, the change in the subsystem's exergy less any work, additional to that done by the pressure reservoir, done on the system) must be less than or equal to zero.
 
i.e. the change in the subsystem's exergy plus the useful work done by the subsystem (or, the change in the subsystem's exergy less any work, additional to that done by the pressure reservoir, done on the system) must be less than or equal to zero.
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也就是。子系统<font color = 'red'><s>(火用)</s></font><font color = 'blue'>有用能</font>的变化加上子系统所做的有用功(或者,子系统<font color = 'red'><s>(火用)</s></font><font color = 'blue'>有用能</font>的变化<font color = 'red'><s>不包括任何功,除了压力贮存器所做的功之外,在系统中所做的功</s></font><font color = 'blue'>减去除了'''<font color = '#ff8000'>压力热源</font>'''外任何对系统做的功,</font>)必须小于或等于零。
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也就是。子系统有用能的变化加上子系统所做的有用功(或者,子系统有用能的变化减去除了'''<font color = '#ff8000'>压力热源</font>'''外任何对系统做的功</font>)必须小于或等于零。
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总之,如果选择一个合适的类似于无限库的参考状态作为现实世界中的系统环境,
 
总之,如果选择一个合适的类似于无限库的参考状态作为现实世界中的系统环境,
<font color = 'red'><s>那么第二定律预测的不可逆性的 e 值会减少,而可逆过程的 e 值不会变化。</s></font><font color = 'blue'>则第二定律预测不可逆过程的''E''值减少,可逆过程的''E''值不变。</font>
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则第二定律预测不可逆过程的''E''值减少,可逆过程的''E''值不变。
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这个表达式和相关的参考状态允许<font color = 'red'><s>在宏观尺度(高于热力学极限)下工作的使用第二定律</s></font><font color = 'blue'>设计工程师在宏观尺度(高于热力学极限)下使用第二定律</font>,而无需直接测量或考虑整个孤立系统中的熵变。(另见'''<font color = '#ff8000'>工艺工程师process engineer</font>''')。<font color = 'red'><s>考虑到这些变化,假设</s></font><font color = 'blue'>这些变化已经在假设中被考虑到,该假设认为</font>所考虑的系统可以在不改变参考状态的情况下与参考状态达到平衡。将其与可逆理想<font color = 'blue'>状态</font>进行比较,还可以找到一个过程或过程集合的效率(见'''<font color = '#ff8000'>第二定律效率second law efficiency</font>''')
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这个表达式和相关的参考状态允许设计工程师在宏观尺度(高于热力学极限)下使用第二定律,而无需直接测量或考虑整个孤立系统中的熵变。(另见'''<font color = '#ff8000'>工艺工程师process engineer</font>''')。这些变化已经在假设中被考虑到,该假设认为所考虑的系统可以在不改变参考状态的情况下与参考状态达到平衡。将其与可逆理想<font color = 'blue'>状态</font>进行比较,还可以找到一个过程或过程集合的效率(见'''<font color = '#ff8000'>第二定律效率second law efficiency</font>''')
    
This approach to the Second Law is widely utilized in [[engineering]] practice, [[environmental accounting]], [[systems ecology]], and other disciplines.
 
This approach to the Second Law is widely utilized in [[engineering]] practice, [[environmental accounting]], [[systems ecology]], and other disciplines.
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