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Steam plant
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EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-1-
1.0 INTRODUCTION
1.1 OBJECTIVES
The objectives for this experiment are:
i) To determine the performance characteristics of a steam plant.
ii) To demonstrate the conversion of energy from one form to another and the
measurement of mechanical power.
iii) To demonstrate thermodynamic principle as applied to laboratory scale
steam plant.
1.2 GENERAL BACKGROUND
Steam engine is a heat engine which makes use of the potential energy that
exists as pressure in steam, and then converts it to mechanical work that leads to
the students understanding on some principles of thermodynamics using a
laboratory scale steam plant. Here, a steam plant will demonstrate the principles
of thermodynamics.
The steam plant consists of several component include a boiler, a steam
engine, a condenser and a feed pump. In large power plants, steam turbine are
used but for a small scale laboratory set up, a steam engine is used. Steam engines
were usually used in pumps, locomotive, train and steam ships. And some are still
used it for electrical power generation. Basically, steam is a colorless expansive
and invisible gas resulting from the vaporization of water. Below are the classes
of steam:
a) Saturated steam.
b) Dry steam.
c) Wet steam.
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-2-
d) Superheated steam.
e) Highly superheated or gaseous steam.
1.3 THEORY
The cycle of operations in a heat engine is based on Rankine Cycle. The
Rankine cycle more closely approximates to the cycle of a real steam engine
compared to the Carnot cycle. It therefore predicts a lower ideal thermal
efficiency than the Carnot cycle. In the Rankine cycle, heat is added at constant
pressure p1, at which water is converted in a boiler to superheated steam causes
the steam expands at constant entropy to a pressure P2 in a condenser; the water
so formed is compressed at constant entropy to pressure P1 by a feed pump.
Figure 1.3(a): The Rankine Cycle System Figure 1.3(b): Diagram of Rankine Cycle
Based on the figures above, the cycle is consists of four processes whereby:
• From 1 to 2: Isentropic expansion (Steam turbine)
• From 2 to 3: Isobaric heat rejection (Condenser)
• From 3 to 4: Isentropic compression (Pump)
• From 4 to 1: Isobaric heat supply (Boiler)
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-3-
For this experiment, firstly consider the complete system of boiler, motor
and condenser surrounded by the control surface. The steady flow energy is given
by:
353211 mhmhQQQQW w −+−−−=
• The overall thermal efficiency of the plant is given by
)( 3
1
1
1
hhms
W
Q
W
w
TH−
==η
• The overall boiler efficiency is given by following this formula
1
1 )(
Q
hhm wsB
−=η
• Rankine cycle efficiency
)( 1
1
hhms
W
w
R−
=η
• Quality of steam
x = h [enthalpy after throttling calorimeter] – hf [@boiler pressure ]
hfg [ @boiler pressure]
• Power W :
60
)21(2 NFFRW
−=
π
R= Brake radius (0.056m)
F = spring load (N)
N = Engine speed (rev. min-1)
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-4-
1.4 OVERALL PROCESS DESCRIPTION
Laboratory scale steam plant is designed in order to leads student to
understand some of principles of thermodynamic. The main components in the
steam plant are such as a boiler, steam engine, condenser and the feed pump.
Steam engine is use to convert potential energy to mechanical energy. Therefore,
water is supplied from the reservoir to the boiler by an electric pump and is heated
inside it by using two immersion heaters (3 kW each). The boiler is to incorporate
a safety valve a water level gauge and a blow-down cock. Boiler to be rated up to
6 kW and to generate up to 8 kg per hour of steam with maximum pressure of 400
kPa.
In this case, the water should be always clean and free from minerals to
prevent any errors or contamination occurs inside it. Here, the steam pressure in
the boiler will rises until it reaches to 4 bars. Then, it will undergo the steam
engine, which by steam engine is a prime mover, and the engine has a totally
enclosed crank case, 2 cast iron trunk pistons and overhead piston valve made of
stainless steel. A simple band brake will absorb this engine power form by steam
engine. This steam is expanded in the steam engine to produce a useful work.
Then, the condenser will condense the exhaust steam from the steam engine from
saturated steam to water. This water is then returned back to the reservoir and
pump back into the boiler and the cycle continues.
Furthermore, this apparatus is also consists of a tachometer to measure
speed, an electrical power meter for measuring the heater power input,
thermocouples with read-outs for steam and cooling water temperatures, and
pressure gauges for boiler and engine inlet pressures. This compressive
instrumentation will provide the user with all the reading necessary to perform
experiment in thermodynamics and efficiency.
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-5-
2.0 METHODOLOGY
2.1 APPARATUS
Figure 2.1: Steam Motor and Energy Conservation Test Set
2.2 OPERATIONS
2.2.1 SETUP & CHECKS
1. The cooling water supply was supplied to the inlet pipe of the
condenser and the outlet pipe was connected to a suitable drain.
The outlet from the condensate collector was connected to a
suitable drain or container.
2. The unit was connected to the electrical supply.
3. The filter on the end of the boiler pump suction pipe was checked
in place and clean. The end of the pipe was placed into the
reservoir tank supplied. The tank was filled with the clean soft
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-6-
water to at least half way. The reservoir was kept half full to ensure
no air is drain in to the pump
4. The upper and lower valves on the boiler sight gauge and the steam
outlet valve on the boiler was opened.
5. The temperature display was switched on.
6. The red emergency stop button was pulled out. The mains supply
and the boiler feed pump was switched on.
7. The pump bleed valve was opened and the pump was operated.
When there is a steady flow of water, with no air bubbles, the
bleed valve was closed and begins to fill the boiler to the upper
mark on the sight gauge. The boiler should fill in 8 to 10 minutes.
When the boiler is full, the boiler steam valve was closed.
8. The band brake was slackening to ensure that the engine is not
loaded. The spring balances was zero.
9. The both heaters was switched on, the indicator lamps will light up
to show the heaters are working. The boiler pressure will rise as
indicated on the boiler pressure gauge. The calorimeter valve was
closed.
2.2.2 START UP
1. When the boiler pressure has reached approximately 60 kN/m2 (0.6
bar), the boiler steam valve was opened until the engine inlet
pressure has reached 40 kN/m2 to 50 kN/m
2 (0.4 bar to 0.5 bar)
2. In one swift movement, the starting knob was pulled upward and
let go. The engine was started to turn. If the engine does not turn:
• Try the starting knob again
• Check the inlet pressure is correct
• Check that the band brake is not too tight
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-7-
• Check that the steam engine is not seized- the pulley was watch
at the front of the engine and see if it turns as you pull the
starting knob upwards.
3. The condenser cooling water was turned on and a flow rate for
about 100 liters/hour was adjusted. As the steam pressure rises, the
engine speed will increase, the steam valve was used to keep
engine ticking over at a pressure of between 40kN/m2 and
50kN/m2
4. The heater was switched on in order to keep the boiler pressure up
to sufficient level. The boiler safety valve will begin to operate at
approximately 340kN/m2 (3.4 bars) but will not be fully open until
400kN/m2. The steam at higher boiler pressure was vented through
the safety valve.
5. The apparatus was run for at least 10 minutes to stabilize before
the reading is taken. The level of water in the boiler was checked
regularly. The feed pump was switched on when necessary so that
the level lies between the permitted limits.
2.2.3 EXPERIMENT PROCEDURES
1. The engine was run at the constant speed 2000 rev per min-1 at
varying engine load with:
a) The right hand spring balance was loaded with 2N stages to
20 N.
b) The boiler pressure was varied to achieve constant speed.
(+ 100 rev. min-1)
2. The parameter was recorded in the data sheet
(The volume of condensate was collected in a measuring cylinder
with 1 minute’s interval for the condensate flow rate.)
3. The results were analyzed.
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-8-
4. After used:
a) The electrical and water supplies were disconnected.
b) The boiler was allowed to cool down and the boiler drain
valve was opened.
c) The water from the apparatus was drained.
d) The temperature display was switched off.
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-9-
3.0 DATA & RESULTS
Table 1: Data for Operating Parameters
*Condenser Cooling Water flowrate, mw = 0.0284 kg/s
Spring
Load
Boiler
Pressure
Boiler
Temp
Engine
Inlet
Pressure
Engine
Speed
Calorimeter
Temp
Condenser
Cooling
H2O inlet
Condenser
Cooling
H2O outlet
Condensate
Flow Rate
Electrical
Power
Condensate
Temp
F1
(N)
F2
(N) P1 (bar) T1 (°C) P2 (bar)
N
(rev/min) T2 (°C) T3 (°C) T4 (°C) Ms (kg/s) Q1 (kW) T5 (°C)
1 0.5 238 139.5 180 1800 101.0 28.8 42.9 161 5.8 41
1 1.0 180 132.6 150 1560 100.8 28.4 40.9 138 5.8 39
1 1.5 200 135.2 180 1480 100.7 28.4 41.4 142 5.8 40
1 2.0 210 136.5 190 1320 100.8 28.4 41.6 142 5.8 40
1 2.5 220 137.8 200 1260 100.8 28.5 41.9 146 5.8 40
1 3.0 230 138.8 210 1230 100.8 28.7 42.4 152 5.8 40.1
1 3.5 240 139.7 220 1160 100.9 28.7 42.6 154.2 5.8 40.1
1 4.0 180 135.7 170 840 100.8 28.7 40.5 130 3.0 40
1 4.5 160 131.3 140 520 100.5 28.7 38.6 112 3.0 39
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-10-
Table 2: Calculated Result based on Data Obtained from the Experiment
Quality of steam in
boiler, X
Boiler efficiency, η Power output of the
engine,W1
Rankine cycle efficiency,
ηR
Thermal efficiency, ηTh
0.9752 96.6878 5.2779 0.0941 0.07633
0.9792 103.8674 9.1483 0.001877 0.1364
0.9776 86.0308 13.0187 0.2609 0.1929
0.7933 69.6215 15.4818 0.3834 0.2289
0.9762 87.9649 18.4726 0.3621 0.2716
0.9755 91.3915 21.6393 0.4082 0.3157
0.9749 92.5617 23.8091 0.4435 0.3461
0.9792 150.8869 19.7041 0.4318 0.5086
0.9806 132.2042 13.7225 0.3459 0.3683
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-11-
Figure 1: Graph of Condensate Flowrate, kg/s vs. Power Output of the Engine, W1
Figure 2: The reliable result for this experiment
Condensate FlowRate, kg/s vs Power Output of the Engine, W1
0
50
100
150
200
0 5 10 15 20 25
Power Output of the Engine, W1
Con
den
sate
Flo
wR
ate
, k
g/s
Efficiency vs. Power Output
0
0.2
0.4
0.6
0.8
1
1.2
0 5 10 15 20 25
Power Output of engine, W1
Ra
nk
ine E
ffic
ien
cy
, T
herm
al
Eff
icie
ncy
, S
tea
m Q
ua
lity
0
20
40
60
80
100
120
Bo
iler
Eff
icie
ncy
Quality of steam in boiler, X Rankine cycle efficiency, ηR Thermal efficiency, ηTh Boiler Efficiency
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-12-
4.0 DISCUSSION
The experiment purposely conducted to make a study on the steam plant operation
and performance in terms of thermodynamic and heat transfer concept. There are 2
different spring loads that we need to adjust in order to observed the significant on the
power output of the engine. For this experiment, F1 is maintaining at 1.0N while the F2
adjusted accordingly by the increment of 0.5N in intervals. The Boiler Pressure and
Temperature readings were taken throughout the experiment for the steam quality and
boiler efficiency calculation. There are others parameters that being recorded like Engine
Inlet Pressure and speed, Calorimeter Temperature, Condenser Cooling Water Inlet
Temperature, Condensate Flowrate and Temperature as well as the Electrical Power
supply to the unit. The experiment carried out until the engine stop running when the load
increases.
For the first trial, the F2 load was set at 0.5N and the Boiler operating condition
recorded at 238 kPa and 139.5oC. By calculation, the steam quality produced was
observed at 0.9752 with the boiler efficiency of about 96.6878%. The power delivered by
the engine calculated to be 5.2779W with the Rankine cycle efficiency observed at
0.0941% with the thermal efficiency indicated at 0.07633%. By referring to the steam
quality produced, there is almost a perfect water vapor phase existence.
The spring load of F2 was set at 1.0N and the steam quality produced was
calculated to be 0.9792 at 180 kPa and 132.6oC of boiler condition. The boiler efficiency
was above than perfect condition in operation, which calculated at 103.8674%. However,
the power generated from the engine observed at 9.1483 W with the Rankine efficiency
of 0.001877% and the thermal efficiency of 0.1364% Eventhough the steam quality
produced was higher compared to the first trial but the possibility of getting the boiler
efficiency greater than 100% is impossible. Thus, this trial was considered failed.
The third trial observed the steam quality produced at 0.9776 with the boiler
efficiency calculated at 86.0308% and the Rankine efficiency observed at 0.2609%. The
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-13-
engine power output measured at 13.0187 W with the thermal efficiency recorded at
0.1929%. The fourth trial with the F2 load set at 2.0 N measured the boiler efficiency at
69.6215% with the steam quality produced monitored at 0.7933. This trial also was not a
desired operation since the steam produced was low. However, the power generated by
the engine recorded at 15.4818 W with the thermal efficiency calculated at 0.2289% and
the Rankine efficiency of 0.3834%.
The steam quality recorded at 0.9762 with the boiler efficiency calculated at
87.9649% at F2 set to 2.5 N. The power output of the engine measured at 18.4726 W
while the efficiency of thermal observed at 0.2716% and the Rankine was at 0.3834%.
The boiler efficiency measured at 91.3915% and the steam produced was calculated at
0.9755 when the F2 set at 3.0 N. This resultant in the engine power to produced 21.6393
W with the thermal efficiency measured at 0.3157% together with the Rankine cycle of
0.4082% efficient. The seventh trial was observed with the F2 set at 3.5 N. The efficiency
of the boiler measured at 92.5617% with the Rankine recorded at 0.4435% and the
thermal was calculated at 0.3461%. For this trial, the steam quality generated was
calculated at 0.9749 with the power of the engine recorded at 23.8091 W.
The eight trial was conducted with the F2 set at 3.5 N with the steam produced
observed at 0.9792 and the boiler efficiency recorded higher than expected which is
almost 150.8869%. The last trial carried out with the F2 load was set at 4.5 N. The steam
produced was calculated at 0.9806 with the power delivered from the engine measured at
13.7225. This experiment recorded the efficiency of boiler at 132.2042%, the Rankine
efficiency at 0.3459% and the thermal efficiency at 0.3683%.
From the data and results obtained, the power output from the engine is increasing
by the increment of the spring load difference. Higher load also lead to higher boiler
efficiency with a direct relation to the Rankine and thermal efficiency as well. From the
results, there is clearly indication on the relationship of all this and can best represented
by Figure 2 above which second, eighth and ninth trial was excluded from the graph since
the efficiency of the boiler was impossible.
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-14-
Eventhough the experiment completed without any major concern, but there are a
few problems encountered during the experiment, which may influence the result. The
first problem that influenced a lot on the calculation is the Boiler Pressure. In this
experiment, the Boiler Pressure fluctuates and not really constant thus affects on the
enthalpy in the steam quality calculation. Second problem faced by the team is on the
water level control in the boiler. Initial start-up of the steam plant observed at zero level
of the steam since the boiler was empty. Thus, the steam generates might takes a few
minutes to complete and the purity of the steam is a concern for this case.
The spring load also can be one of the contributors to the misleading on the result.
The spring was vibrated throughout the experiment and impacted on the actual delta load.
Since the scale on the spring also was a bit unclear, the exact measurement during setting
up the load was not accurate. The last problem that may influence the result is on the
water volume measurement. Since the condensate collected in the beaker, the accuracy on
the actual volume may impact on the efficiency calculation.
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-15-
5.0 CONCLUSION
Based on the result, there is a proven that the steam plant can produced a high
quality of water vapor mixture, which is around 97%. From the relationship, there is
significant increment on the power input of the engine when the load is increasing. Thus,
we can conclude that the higher the load, the higher the power output from the engine.
This direct relationship also linked to the boiler, Rankine and thermal efficiency which
the higher the load, the better the efficiency.
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-16-
6.0 TUTORIAL
1. Based on the Figure 2, derive
a. Engine work, W1
Energy Balance for the system:
( ) ( )3543211
3154321
hhmQQQQQW
mhmhWQQQQQ
EWQ
w
w
−+−−−−=
−=−−−−−
∆=−
b. Thermal efficiency, ηTh
General Equation:
in
out
THQ
W=η
Thus, based on Figure 2
32
121
1
:
:
:
mhmhCondenseratBalanceEnergy
WmhmhEngineatBalanceEnergy
mhmhBoileratBalanceEnergy w
=
+=
=
( )
( )
1
3
1
21
1
1
Q
hhm
Q
hhm
Q
W
wTH
TH
TH
−=
−=
=
η
η
η
c. Boiler efficiency, η
( )
1
1
11 )(
Q
hhm
hhmW
EW
wB
w
−=
−=
∆=
η
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-17-
2. How to increase the efficiency of the Rankine Cycle? Please explain.
• The basic idea to increase the efficiency of the Rankine Cycle is increase the
average temperature at which heat is transferred to the working fluid in the
boiler or decrease the average temperature at which heat is rejected from the
working fluid in the condenser.
• There have three ways to increase efficiency based in simple ideal Rankine
Cycle:-
� Lowering the Condenser Pressure (Lower T low,avg)
� Lowering the operating pressure of the condenser automatically lowers
the temperature of the steam and thus the temperature at which heat is
rejected.
� Superheating the Steam to High Temperatures (Increase T high,avg )
� The average temperature at which heat is transferred to steam can be
increased without increasing the boiler pressure by superheating the
steam to high temperature.
� Increasing the Boiler Pressure (Increases T high,avg)
� Increase the operating pressure of the boiler, thus automatically raises
the temperature at which boiling takes place.
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-18-
3. What are the differences between the actual vapor cycle and the ideal
Rankine Cycle?
Actual Vapor Cycle
Figure 1: Deviation of Actual Vapor Cycle from the Ideal Rankine Cycle
The actual vapor power cycle differs from the ideal Rankine cycle as a result of
irreversiblities in various components. The two common sources of irreversiblities are the
friction and undesired heat loss to the surroundings. Fluid friction causes pressure drops
in the boiler, the condenser, and the connecting pipes. To compensate for these pressure
drops, the water needs to be pumped to a higher pressure. Heat loss from steam to
surroundings takes place when steam flows through the connecting pipes and the various
components. To maintain the same work output, more heat needs to be transferred to the
steam in the boiler. The deviation of actual pumps and turbines from the isentropic ones
can be accounted for by utilizing adiabatic efficiencies
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-19-
Ideal Rankine Cycle
Figure 2: T-s Diagram of an Ideal Rankine Cycle
The Rankine cycle is an ideal cycle if water passes through the four components without
irreversibilities and pressure drops. The ideal Rankine cycle consists of the following
four processes, as shown on the T-s diagram above:
• 1-2: Isentropic compression in a pump
• 2-3: Constant pressure heat addition in a boiler
• 3-4: Isentropic expansion in a turbine
• 4-1: Constant pressure heat rejection in a condenser
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-20-
7.0 APPENDIX
Steam Quality Calculation
CT
kPa
kPakPaP
01012
325.339
325.1012381
=
=
+=
( )( )
kgkJh
kgkJ
kgkJh
C
C
TableSteamfromerpolationonBased
Cathh
o
o
o
g
/16.2677
/)6.26754.2683(
/)6.2675(
100105
100101
:int
101
=
−
−=
−
−
=
( )( )
( )( )
kgkJh
kgkJ
kgkJh
kPa
kPa
erpolationguBy
kPaath
f
f
f
/53311.579
/19.57326.584
/19.573
325350
325325.339
:intsin
325.339
=
−
−=
−
−
( )( )
( )( )
kgkJh
kgkJ
kgkJh
kPa
kPa
erpolationguBy
kPaath
g
g
g
/9879.2150
/4.21557.2147
/4.2155
325350
325325.339
:intsin
325.339
=
−
−=
−
−
( )
9752.0
/9879.2150
/53311.57916.2677
=
−=
−=
x
kgkJ
kgkJx
h
hhx
fg
fg
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-21-
Boiler Efficiency
kgkJh
kgkJkgkJh
xhhh fgf
/17651.2677
)/9879.2150(9752.0/53311.579
1
1
1
=
+=
+=
( )( )
( )( )kgkJh
kgkJ
kgkJh
C
C
Cathh
f
f
o
o
o
fw
/019.587
/75.56716.589
/75.567
135140
1355.139
5.139
=
−
−=
−
−
=
s
kgm
sm
kg
L
m
ml
Lmlm
s
s
002683.0
60
min11000
1000
1
1000
1
min
1613
3
=
××××=
( )
%6878.96
100
8.5
019.58717651.2677002683.0
100)( 1
=
×
−
=
×−
=
B
B
fs
B
kg
kJ
kg
kJ
s
kg
Q
hhm
η
η
η
Power Output of the Engine, W
WW
rpmNmW
NFRW
2779.5
60
)1800()5.0()056.0(2
60
)(2
=
=
∆=
π
π
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-22-
Rankine Cycle Efficiency
%0941.0
100
)17651.2677019.587(002683.0
2779.5
100)( 1
=
×
−
=
×−
=
R
R
ws
R
kg
kJ
s
kg
W
hhm
W
η
η
η
Thermal Efficiency
( )( )
( )( )
kgkJh
kgkJ
kgkJh
C
C
Cathh
CT
o
o
o
f
o
/712.171
/53.16744.188
/53.167
4045
4041
41
415
3
3
3
=
−
−=
−
−
=
=
%07633.0
100
)712.171019.587(002683.08.5
2779.5
100)( 3
=
×
−+
=
×−+
=
th
th
ws
th
kg
kJ
s
kg
s
kJ
W
hhmQ
W
η
η
η
EXPERIMENT 2: PERFORMANCE OF A STEAM PLANT
THERMODYNAMIC (CLB 20704)
-23-
8.0 REFERENCES
1. http://en.wikipedia.org/wiki/Steam_power
2. http://en.wikipedia.org/wiki/Heat_engine
3. http://electron9.phys.utk.edu/phys136d/modules/m3/heatpump.htm
4. http://en.wikipedia.org/wiki/Thermodynamics
5. http://en.wikipedia.org/wiki/Rankine_cycle
6. http://www.taftan.com/thermodynamics/RANKINE.HTM
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