Help thermo entropy generation

In summary, the conversation discusses two schemes for delivering atmospheric air from 300K and 100kPa to a line at 600K and 200kPa. The first scheme involves reversible adiabatic compression followed by internally reversible isobaric heating, while the second scheme involves internally reversible isobaric heating followed by reversible adiabatic compression. Heat exchange with a reservoir at 900K is assumed in both cases. The equations used in determining work and entropy generation are also mentioned. The difference between the two schemes is not immediately clear, and the question of the change in entropy for any adiabatic reversible compression and the change in entropy regardless of the process path is raised.
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Homework Statement


Atmospheric air at 300K and 100kPa is to be delivered to a line at 600K, 200kPa. Two possible schemes for doing this are suggested. The first scheme involves reversible adiabatic compression and then internally reversible isobaric heating. .The second scheme involves internally reversible isobaric heating first and then reversible adiabatic compression. In both cases heat exchange takes place with a reservoir at 900K. Assume an ambient condition of 100 kPa, 300K.

a) Determine work and entropy generation for both of the suggested ways.

Homework Equations


Q=m.Tb(s2-s1)-Tb.sigma sigma= entropy

The Attempt at a Solution


heat transfer only occurs at Tb, ignore KE Pe, air is ideal gas

mass and energy balances at steady state W=Q+m(h1-h2)
entropy balance gives Q/Tb+m(s2-s1)+sigma

I don't understand the difference betwwen 1 and 2
 
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  • #2
What is the change in entropy for any adiabatic reversible compression? What is the change in entropy in going from 300 K and 100 kPa, to 600 K and 200 kPa, irrespective of the process path?
 

1. What is thermo entropy generation?

Thermo entropy generation is a measure of the amount of disorder or randomness that is produced in a thermodynamic system. It is a measure of the inefficiency of a process, as any energy conversion will always result in some amount of entropy generation.

2. How does thermo entropy generation affect the efficiency of a system?

As thermo entropy generation is a measure of a system's inefficiency, it directly affects the efficiency of a system. The more entropy generated, the less efficient the system is in converting energy and the more waste is produced.

3. What factors contribute to thermo entropy generation?

There are several factors that contribute to thermo entropy generation, including temperature differences, irreversibility of processes, friction, and inefficiencies in energy conversion. These factors all lead to an increase in disorder and randomness in the system, resulting in entropy generation.

4. Can thermo entropy generation be reduced or eliminated?

While it is impossible to completely eliminate entropy generation, it can be reduced by improving the efficiency of a system. This can be achieved by minimizing temperature differences, reducing friction, and optimizing energy conversion processes.

5. How is thermo entropy generation used in practical applications?

Thermo entropy generation is an important concept in thermodynamics and is used in practical applications such as power generation, refrigeration, and heat engines. By understanding and minimizing entropy generation, engineers can design more efficient and sustainable systems.

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