Question

A piston-cylinder device contains 0.54 kg of steam at 300 degrees C and 3 MPa. Steam is cooled at constant pressure until one-half of the mass condenses. (A) Find the final temperature (B) Determine the volume change

Answer #1

A piston-cylinder device with a set of stops initially contains
0.35 kg of steam at 1.0 MPa and 900 degrees C. The location of the
stops corresponds to 44 percent of the initial volume. Now the
steam is cooled. Determine the magnitude of the compression work if
the final state is (A) 1.0 MPa and 600 degrees C and W=. kJ (B) 500
kPa. W=. kJ (C) Also determine the temperature at the final state
in part (B). T2=. C

Entropy From Steam Tables
A piston-cylinder assembly contain 2 kg of water. The water is
initially at the pressure of 0.5 MPa and the temperature of 300°C.
The water is cooled down at constant pressure process until it is a
saturated vapor. Determine the change in the entropy of the
system.

H3.3 A frictionless piston-cylinder device contains 2 kg of H2O
initially at T1 = 300◦C and p1 = 5 bar. The device is cooled at
constant pressure until the volume is ∀2 = 0.5 m3 . Assume a
quasiequillibrium process which occurs slowly with no acceleration
as the piston moves. Kinetic and potential energy effects are
negligible. Determine: a. work [kJ] during process (indicate
magnitude and direction) b. heat transfer [kJ] during process
(indicate magnitude and direction)

2 kg of steam initially at 2.00 MPa and 225?C expands in a
piston-cylinder assembly until the final pressure is 0.10 MPa.
During the process, the temperature of steam is kept constant by
keeping it in a constant temperature atmosphere at 225?C. a. What
is the maximum amount of work that can be produced? What is the
entropy change of steam? What is the entropy change of the
universe? b. Suppose that the actual work done is 80% of the...

A piston cylinder device contains 0.15 kg of air initially at 2
MPa and 350 C. First, the air expands isothermally to a pressure of
500 kPa. Then, it is compressed polytropically back to the initial
pressure (2 MPa) with a polytropic exponent of 1.2. Find the work
performed or introduced by or to the air for each process. Express
it both times in kJ.

A piston cylinder device contains a mixture of 0.2 kg of H2 and
1.6 kg of N2 at 100 kPa and 300K. Heat is now transferred to the
mixture at constant pressure unitl the volume is doubled. Assuming
constant specific heats at the average temperature (the constant
pressure specific heats of H2 and N2 are 14.501 kJ/kg°K and 1.049
kJ/kg°K, respectively), determine: a) the heat transfer. b) the
entropy change of the mixture.

A piston-cylinder contains 2 kg of refrigerant R-134a at
temperature -20 degrees Celsius and a quality of 20% is heated in
device until it reaches a saturated mixture with quality 60%. a)
Show process on a P-v and P-T diagram b) What is the pressure? c)
What is the change in volume? d) What is the change in the internal
energy? e) Redo the problem if the piston-cylinder assembly is
replaced with a rigid container.

steam is contained in a piston and cylinder assemble at a
pressure of 5 bar and temperature of 700 degrees celcius. At this
initial condition, the cylinder is restrained by stops since the
pressure is applied on piston only supprts a pressure of 3 bar in
the cylinder. The initial volume of system is 1m^3 and cooling is
applied to the system until final volume is 0.1m^3. Determine work
and heat transfer.

A piston-cylinder device initially contains 75 g of saturated
water vapor at 340 kPa . A resistance heater is operated within the
cylinder with a current of 0.6 A from a 300 V source until the
volume doubles. At the same time a heat loss of 7 kJ occurs.
Part A)Determine the final temperature (T2).
Part B)Determine the duration of the process.
Part C)
What-if scenario: What is the final
temperature if the piston-cylinder device initially contains
saturated liquid water?

A 0.2 m3 piston-cylinder initially contains 400 K air. A heavy
frictionless piston maintains a pressure of 500 kPa abs. Then, a
weakness in the cylinder wall blows out and creates a hole. Air
escapes through the hole until the piston drops far enough to cover
the hole. At that point, the volume is half the initial volume.
During this process, 75 kJ of heat is transferred to the 100 kPa,
300 K surroundings. Using Cp = 1.005 kJ/kg-K and...

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