Closed system analysis: Solid and liquid
1. An unknown mass of aluminum at 60C is dropped into an insulated tank that contains 40 L of
water at 25C and atmospheric pressure. If the final equilibrium t
Discharging Process
1. A 0.1 m3 rigid tank contains saturated refrigerant 134a at 800 kPa. Initially, 40
percent of the volume is occupied by liquid and the rest by vapor. A valve at the
bottom of the
1. Steam at 10 MPa and 550C enters the first-stage turbine of an ideal Rankine
cycle with reheat. Steam enters the second-stage turbine after being reheated to the
same temperature as of the superheat
1. Steam 6 MPa, 500C enters in a high-pressure turbine (in a reheat cycle) and
expand to state of saturated dry steam. The steam is reheated to 500C and
expanded in the second stage (low pressure) at
Power Cycle
Rankine Cycle
1. Consider a 300 MW steam power plant that operates on a Rankine cycle. Steam enters the turbine at 10
MPa and 500C and is cooled in the condenser at a pressure of 10 kPa. D
Ex. Steam at 6 MPa and 500C enters the high-pressure turbine and is
expanded to state of saturated dry steam. The steam is then reheated to
500C and expanded in the second stage (low pressure turbine)
1. Two Carnot engines operate in series between two reservoirs maintained at
527C and 40C, respectively. The first engine rejects 90 MJ of energy every
hour which is utilized as energy input to the se
Power Cycle
1. Rankine Cycle
Boiler
Turbine
pump
Condenser
w
tur
2. Reheat Rankine Cycle
Boiler
Turbine
pump
Condenser
w
tur
3. Regenerative Rankine Cycle
Boiler
Turbine
w
pump
open
FWH
pump
Condenser
Entrnpy Changes Bf Pure Substances T—34 A well-insulated rigid tank contains 2 kg of a satu-
lated liquid—vapor mixture of water at ltlﬂ kPa. Initially,
lhree-quarters of the mass is in the liquid pha
Power Cycle
1. Consider a 300 MW steam power plant that operates on a Rankine cycle.
Steam enters the turbine at 10 MPa and 500C and is cooled in the condenser
at a pressure of 10 kPa. Determine
a) Th
Refrigeration Cycles
1. Refrigerator and Heat Pump
q out
T
2
condenser
2
3
compressor
w
com
3
1
4
4
1
evaperator
q in
s
2. Gas Refrigeration Cycle
Q
4
heat
exchanger
out
3
T
3
turbine
compressor
W
net
Power Gas Cycles
Otto Cycle
1. A six-cylinder engine with a compression ratio of 8 and a total volume at TDC
of 600 mL intakes atmospheric air at 20C. The maximum temperature during
a cycle is 1500C.
The Second Law of Thermodynamics
Heat engine and thermal efficiency.
1. A steam power plant receives heat from a furnace at a rate of 280 GJ/h. Heat
losses to the surrounding air from the steam as it
Power Gas Cycle
1. The Air-Standard Cycle
In this section we introduce engines that utilize a gas as the working fluid.
Spark-ignition engines that burn gasoline and compression-ignition (diesel)
engi
Refrigeration Cycles
Refrigerator and Heat Pump
1. An ideal refrigeration cycle uses ammonia as the working fluid between
saturation temperature of -40C and 10C. If the refrigerant mass flux is 1
kg/s
Adiabatic efficiency of turbine and compressor
1. Steam enter turbine at 2 MPa and 400C and leave at 10 kPa determine
temperature at exit when turbine efficiency is 85%.
2. Steam enters turbine at 400
Work
1. A mass of 5 kg of saturated water vapor at 200 kPa is heated at constant pressure
until the temperature reaches 300C. Calculate the work done by the steam
during this process. (430.5 kJ)
2. A
System: is defined as a portion of the mass chosen for a thermodynamic analysis.
- Closed system or control mass: the system that consists of a fixed amount of mass. No
mass and energy cross the secti
1. Steam with x = 0.85 is contained in a rigid vessel a pressure of 200 kPa. Heat is added until
temperature reach 600C
a) Sketch the process on a T-v diagram.
b) Calculate the heat transferred to the
First Law of Thermodynamic
Closed system
1. A piston-cylinder device contains 5 kg of refrigerant-12 at 800 kPa and 60C. The
refrigerant is now cooled at constant pressure until it exists as a liquid
First Law of Thermodynamic
Open system
1. Steam flows steadily through an adiabatic turbine. The inlet conditions of the
steam are 10 Mpa, 450C, and 80 m/s, and the exit conditions are 10 kPa, 92
perc
1. Steam with x = 0.85 is contained in a rigid vessel a pressure of 200 kPa. Heat
is added until temperature reach 600C
a) Sketch the process on a T-v diagram.
b) Calculate the heat transferred to the
EXERCISES FOR SECTIION 13-4
13-3. An article in Industrial Quality Control (1956, pp. 5-8) describes an experiment to investigate
the effect of two factors (glass type and phosphor type) on the bright
Properties of Pure Substance
Thermodynamics: the science that includes the study of energy transformation and the
relationship among the physical properties of substance when are affected
by these tra
Property of pure substance
Property table
1. Complete the following table for H2O
1.1)
T, C
50
P, kPa
v, m3/kg
12.03
200
400
600
250
110
Phase description
Sat. vapor
1.2)
T, C
130
P, kPa
u, kJ/kg
2300
Properties of Pure Substance
Thermodynamics: the science that includes the study of energy transformation and the relationship
among the physical properties of substance when are affected by these
tra
Phase
Compressed
liquid
Sat. liquid
Sat. mixture
Sat. vapor
Superheated
vapor
For sat mixture
v = vf + xvfg
u = uf + xufg
h = hf + xhfg
s = sf + xsfg
Know P&T
P>Psat for given T
T<Tsat for given P
P=P
3—54 A {LS-n1.J vessel contains 1U kg of refrigerant—l34a at 3—59 A piston—cyiinder device initiaily contains 51'} L of
-3]”C. Detennine (a) die pressure, U3} die total internal 1iquid water at 4D=C a
3—54 _ﬁ~.(J.5-m3 vessel contains Ii] kg of refrigerant-l34a at 3—59 A piston—cylinder device initiaIJy contains SCI L of
-HJ‘C. Determine (a) the pressure, (in) the tota] interna] liquid water at 43":
Properties of Pure Substance
Thermodynamics: the science that includes the study of energy transformation and the relationship
among the physical properties of substance when are affected by these
tra