Question

A piston - cylinder device, whose piston is resting on a set of stops, initially contains 2 kg of air at 300 kPa and 27 degree C. The mass of the piston is such that a pressure of 600 kPa is required to move it. Heat is now transferred to the air until its volume doubles.

a) Show the process on p - V and p - T diagrams.

b) Determine the work done by the air.

c) Determine the rate of heat transfer to the air.

Answer #1

Please rate positively

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?

0.75 kg of refrigerant-134a at 120 kPa and 20°C
initially fills a piston-cylinder device. Heat is now transferred
to the refrigerant from a source at 150°C, and the piston which is
resting on a set of stops, starts moving when the pressure inside
reaches 140 kPa. Heat transfer continues until the temperature
reaches 90°C. Assuming the surrounding to be at 25°C and 100 kPa,
determine (a) the work done, (b) the heat transfer, (c) the exergy
destroyed, and (d) the...

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

An insulated piston–cylinder device initially contains
20 L of air at 140 kPa and 27 °C. Air
is now heated for 10 min by a 100-W resistance heater placed inside
the cylinder. The pressure
of air is maintained constant during this process, and the
surroundings are at 27 °C and 100 kPa.
Determine the exergy destroyed during this process.

A
piston-cylinder device contains 3.2 kg of air at 400 kPa and 10°C.
Heat is transfered to air and the piston is allowed to expand at
constant pressure until its temperature reaches 50°C. The work done
during this expansion process is: Use kj units

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)

In a piston cylinder device, initially 0.005 m3 liquid water and 0.9 m3 water vapor are at equilibrium at 600 kPa. Heat is given at constant pressure until the final temperature reaches 200 ° C.
(a) Show the process in the P-v and T-v diagram
(b) What is the initial temperature of the water?
(c) Find the total mass of water
(d) Calculate the final volume

1-kg water in a frictionless piston-cylinder device is initially
at 250°C and 300 kPa (state
1). A total of 700 kJ of work is done ON the water
in order to isothermally reduce its volume to
1/20 of its initial volume (state 2). Determine the magnitude and
direction of the heat transfer
involved in this process.
Answer: -1147 kJ.

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...

Air in a closed piston cylinder device is initially at 800 K and
at 250 kPa.
The air undergoes a process until it is at 2200 K and at 750
kPa.
What is the change in the air's specific entropy during
this process (kJ/kgK)?

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 4 minutes ago

asked 5 minutes ago

asked 26 minutes ago

asked 39 minutes ago

asked 39 minutes ago

asked 43 minutes ago

asked 47 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago