Question

A rigid container with a volume of 2 m3 initially contains 0.05 m3 of liquid and 1.95 m3 of vapor at 125 kPa. Heat is transferred from a 3000C source to the contents of the vessel until the pressure in the container reaches 4 MPa. The contents of the vessel are now cooled in a surrounding temperature of 250C until the contents reach its initial state.

Determine total entropy generated (Sgen) during the cycle.

Answer #1

A rigid container of volume 0.2 m3 contains 5 kg of water at 20
◦C. The maximum allowable pressure of the container is set at 10
MPa. The system is now connected to a heat source, which transfers
heat at a rate of 1000 W to the container. How long will the
container survive?

Initially (state 1) a well-insulated rigid tank contains 20 kg
of a saturated liquid-vapor mixture of water at 100 kPa and half of
the mass is in the liquid phase. An electric resistance heater
placed in the tank is now turned on and kept on until all the
liquid in the tank is vaporized (state 2). Determine (a) the
initial specific volume in m3/kg, (b) the final specific
entropy in kJ/kg.K and (c) change of entropy in kJ/K.

A rigid tank has a volume of 0.01 m3. It
initially contains saturated water at a temperature of 200
oC and a quality of 0.4. The top of the
tank contains a pressure regulating valve which maintains the vapor
at constant pressure. This system undergoes a process where it is
heated until all the liquid vaporizes. How much heat in (kJ) is
required? You may assume there is no pressure drop in the exit
line.

Steam is contained in a closed rigid container with a volume of
2 m3 . Initially, the pressure and the temperature of the steam are
7 bar and 400°C, respectively. The temperature drops as a result of
heat transfer to the surroundings. i. Determine the temperature at
which the condensation first occurs in °C. [6 marks] ii. Evaluate
the fraction of the total mass that has condensed when the pressure
reaches 0.75 bar. [4 marks] iii. Calculate the volume in...

Steam is contained in a closed rigid container with a volume of
2 m3 . Initially, the pressure and the temperature of the steam are
7 bar and 400°C, respectively. The temperature drops as a result of
heat transfer to the surroundings. i. Determine the temperature at
which the condensation first occurs in °C. [6 marks] ii. Evaluate
the fraction of the total mass that has condensed when the pressure
reaches 0.75 bar. [4 marks] iii. Calculate the volume in...

A rigid container of volume 1 m3 contains saturated water at 1Mpa.
If the quality is 0.10, what is the volume occupied by the
vapor?

Q3. A tank with rigid walls and a volume of
0.05 m3 initially has a two-phase liquid- vapor mixture of ammonia
at a pressure of 4 bar and a quality of 10%. The tank is then
heated such that the pressure is kept constant through a
pressure-regulating valve that allows saturated vapor to escape.
The heating continues until the quality of the mixture in the tank
is 40%. Assume kinetic and potential energy changes are
insignificant. Determine:
(i) The final...

An initially empty, well insulated, rigid tank with a volume of
2 m3 is fitted with a mixing device. The tank has two inlets and
zero outlets. One inlet is water at 1 MPa and 600◦C while the other
is saturated liquid water. Both enter the tank slowly. If the
amount of work done by the mixing device is 300 kJ, what must the
temperature of the saturated liquid water be if the same mass is
added through both inlets...

Water of mass 2 kg in a closed, rigid tank is initially in the
form of a twophase liquid-vapor mixture. The initial temperature is
50° C. The mixture is heated until the tank contains only saturated
vapor at 110° C.
(i) Find the initial pressure, in kPa.
(ii) Find the work for the process, in kJ.
(iii) Find the heat transfer for the process, in kJ.

A 0.6-m3 rigid tank is filled with saturated
liquid water at 170
°C. A valve at the bottom of
the tank is now opened, and one-half of the total mass is withdrawn
from the tank in liquid
form. Heat is transferred to water from a source of 210 °C so that
the temperature in the tank
remains constant. Determine (a) the amount of heat transfer and (b)
the reversible work and
exergy destruction for this process. Assume the surroundings to...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 4 minutes ago

asked 7 minutes ago

asked 7 minutes ago

asked 7 minutes ago

asked 21 minutes ago

asked 23 minutes ago

asked 24 minutes ago

asked 25 minutes ago

asked 30 minutes ago

asked 43 minutes ago

asked 45 minutes ago

asked 48 minutes ago