# Carnot Heat Engine and Well-Insulated Piston Cylinder Systems

Problem 1 can only be solved per unit mass- eg work per unit mass, volume per unit mass, since there is not enough info to calculate the system mass.

Instructions: Solve the following problems. Be sure to include a sketch indicating the system and its interactions with the surroundings and state all necessary assumptions. Identify all relationships and provide symbolically before inserting numbers. Identify state models utilized and sources of necessary property data. Submitted should be neat and easy to follow. Sloppy work will not be graded.

1) The working fluid contained in a well-insulated piston cylinder is expanded in a quasi-equilibrium process from 1000oF and 350 [psia] until the temperature is 150oF. Calculate the final pressure and volume and the work done by the system if

a. the working fluid is oxygen and specific heat is constant, and

b. the working fluid is steam

2) The heat addition process of a Carnot heat engine utilizing a piston-cylinder mechanism is executed by vaporizing saturated liquid R134a at 100 [kPa] to saturated vapor.

a. What must be true about the pressure during this process? Why?

b. Calculate the heat added during the process

i. Using the first law.

ii. Using the second law

#### Solution Preview

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1) The working fluid contained in a well-insulated piston cylinder is expanded in a quasi-equilibrium process from 1000oF and 350 [psia] until the temperature is 150oF. Calculate the final pressure and volume and the work done by the system if

a. the working fluid is oxygen and specific heat is constant, and

b. the working fluid is steam

2) The heat addition process of a Carnot heat engine utilizing a piston-cylinder mechanism is executed by vaporizing saturated liquid R134a at 100 [kPa] to saturated vapor.

a. What must be true about the pressure during this process? Why?

b. Calculate the heat added during the process

i. Using the first law.

ii. Using the second law

Solutions:

1) Since the cylinder is well insulated, the process is adiabatic and the quasi-equilibrium condition means that the process is reversible as well, therefore we deal with an isentropic process.

a) If the working fluid is oxygen and the specific heat is constant, the process is governed by the equation:

( ...

#### Solution Summary

Carnot heat engine and well-insulated piston cylinder systems are examined. The working fluid of the piston cylinder in quasi-equilibrium process is analyzed.