The maximum reversible work in thermodynamics (2)

In summary, "The maximum reversible work in thermodynamics (2)" discusses the principles governing the maximum work that can be extracted from a thermodynamic system during a reversible process. It emphasizes the importance of the second law of thermodynamics, which states that no process can be 100% efficient due to entropy production. The document explores various scenarios and conditions under which maximum reversible work can be calculated, highlighting the relationships between pressure, temperature, and the properties of the working substance. The analysis includes mathematical formulations and practical examples to illustrate the concepts, underscoring the significance of understanding reversible processes in optimizing energy conversion systems.
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Homework Statement
Open system, maximum reversible work relative to the dead state in a thermodynamic process. I will share the solution process with everyone, and please correct me if there are any mistakes.
Relevant Equations
Exergy balance
Energy balance
Entropy balance
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referencesol
The maximum reversible work in thermodynamics
Below is the process of determining the "Available energy" for an open system, shared with everyone as a reference for learning about exergy. If there are any errors in the content, please feel free to correct them.

$$ W_{rev}=W_u^{\nearrow W-P0\cancel{\left( V_2-V_1 \right) }=W}+T0\cdot Sgen=W+T0\cdot Sgen $$
Find## W ## and## T_0\cdot Sgen ## :
$$ eneger\ balance:\ \ Q_{in,net}^{\nearrow ^{\sum{Q_k}}}-W_{out,net}^{\nearrow ^W}+m\left( h_i-h_e \right) =\cancel{\bigtriangleup E_{sys}} $$
$$ \therefore W=\sum{Q_k}+m\left( h_i-h_e \right) $$
$$ entropy\ balance:\ \cancel{\bigtriangleup S_{sys}}=\sum{\frac{Q_k}{T_k}}+m\left( s_i-s_e \right) +Sgen $$
$$\therefore T_0Sgen=-\sum{\frac{\ T_0}{T_k}}Q_k-T0\cdot m\left( s_i-s_e \right) $$
$$ \therefore W_{rev}=\sum{\text{(}1-\frac{\,\,T_0}{T_k}\text{)}}Q_k+m\left[ \left( h_i-h_e \right) -T_0\left( s_i-s_e \right) \right] $$
$$ \therefore w_{rev}=\sum{\text{(}1-\frac{\,\,T_0}{T_k}\text{)}}q_k+\left[ \left( h_i-h_e \right) -T_0\left( s_i-s_e \right) \right] =\text{(}1-\frac{\,\,T_0}{T_1}\text{)}q_1+\text{(}1-\frac{\,\,T_0}{T_2}\text{)}q_2+\left[ \left( h_i-h_e \right) -T_0\left( s_i-s_e \right) \right]…. (Ans:w_{rev})$$
$$ i=w_{rev}-w_u^{\nearrow ^0}=w_{rev}............\left( Ans:i \right) $$
 
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I agree with the result in the reference you gave.
 
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FAQ: The maximum reversible work in thermodynamics (2)

What is maximum reversible work in thermodynamics?

Maximum reversible work refers to the highest amount of work that can be extracted from a thermodynamic system as it undergoes a reversible process. In a reversible process, the system remains in equilibrium with its surroundings, allowing for the most efficient energy transfer without any dissipative losses.

How is maximum reversible work calculated?

The maximum reversible work can be calculated using the formula W = ΔG, where W is the work, and ΔG is the change in Gibbs free energy of the system. For processes at constant temperature and pressure, this relationship helps determine the maximum work obtainable from a system.

What are the conditions for achieving maximum reversible work?

To achieve maximum reversible work, the process must be carried out infinitely slowly, maintaining equilibrium at every stage. This means that the system must not experience any friction, turbulence, or other forms of irreversibility, and it should operate under ideal conditions where all changes are reversible.

Why is maximum reversible work important in thermodynamics?

Maximum reversible work is important because it sets a theoretical limit on the efficiency of thermodynamic processes. Understanding this concept helps engineers and scientists design systems that approach this limit, which is crucial for optimizing energy conversion, such as in engines, refrigerators, and chemical reactions.

How does the concept of entropy relate to maximum reversible work?

Entropy is a measure of disorder in a system, and it plays a critical role in determining the feasibility of processes. In reversible processes, the change in entropy of the system and surroundings is zero. Thus, maximizing reversible work involves minimizing entropy production, which is associated with irreversible processes. Understanding entropy helps in evaluating the efficiency of energy transformations and the limits of work extraction.

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