Theromdoynamics-TV diagram & Heat Engine

In summary, there is a misconception that the pressure should remain constant throughout a process, but in reality, it can change depending on other variables such as temperature. Quasi-static equilibrium is necessary for engine efficiency because it allows for simplified calculations, but in real processes, it is not always achievable.
  • #1
jahlin
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1. The pressure is constant at 1Mpa how come it goes up after touching saturation vapor line.?Shouldn't it remain constant throughout?

Please look at the Tv diagram below:
http://www.ent.ohiou.edu/~thermo/Intro/Chapt.1_6/ideal_gas/tv_ideal.gif

2. Why quasi-static equilibrium is necessary for engine efficiency?

Thanks.
 
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  • #2
1. Where does it say the pressure is increasing?
2. A real process is not quasi static. It's an assumption made to make all the calculations easier.

Btw is this homework.
 
  • #3
jahlin said:
1. The pressure is constant at 1Mpa how come it goes up after touching saturation vapor line.?Shouldn't it remain constant throughout?

Please look at the Tv diagram below:
http://www.ent.ohiou.edu/~thermo/Intro/Chapt.1_6/ideal_gas/tv_ideal.gif

2. Why quasi-static equilibrium is necessary for engine efficiency?

Thanks.

That graph is showing a temperature rise after it leaves the saturated-mixture region, the pressure is still constant.

CS
 
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  • #4
xxChrisxx: no its not a homework question.

StewartCs:thanks a bunch!
 

Related to Theromdoynamics-TV diagram & Heat Engine

1. What is a theromodynamics-TV diagram?

A theromodynamics-TV diagram, also known as a temperature-entropy diagram, is a graphical representation of the changes in temperature and entropy of a thermodynamic system. It is often used to analyze the efficiency of heat engines and refrigeration cycles.

2. How do you read a theromodynamics-TV diagram?

To read a theromodynamics-TV diagram, you must first understand the axes. The horizontal axis represents the specific entropy of the system, while the vertical axis represents the temperature. The curves on the diagram represent different processes, such as isothermal, adiabatic, and isentropic. By following a specific curve, you can track the changes in temperature and entropy of the system.

3. What is a heat engine?

A heat engine is a device that converts heat energy into mechanical work. It operates by taking in heat from a high-temperature source, converting some of it into work, and rejecting the remaining heat to a low-temperature sink. Examples of heat engines include steam engines, gas turbines, and car engines.

4. How is efficiency calculated on a theromodynamics-TV diagram?

The efficiency of a heat engine can be calculated by dividing the work output by the heat input. On a theromodynamics-TV diagram, the efficiency can be determined by calculating the area enclosed by the curve representing the heat input and the curve representing the work output. The closer the area is to the work output curve, the more efficient the heat engine is.

5. What factors affect the efficiency of a heat engine?

The efficiency of a heat engine is affected by several factors, including the temperature difference between the hot and cold reservoirs, the type of working fluid used, and the design of the engine. Generally, the larger the temperature difference and the more efficient the working fluid, the higher the efficiency of the heat engine.

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