The University of Jordan
Faculty of Engineering and Technology
Thermodynamics Lab Report
Expirement No.2
Instructor: Eng. Rebhi Al-Mashaleh
Students Names:
Fareed Shatara
2110302
‫فريد ماهر شطارة‬
Hanna Mansour
0128358
‫حنا سليم منصور‬
Ghassan Hjazi
0127296
‫غسان حجازي‬
Ahmad Abu Malloh 0127293
‫أحمد ابو ملوح‬
Omar Al Khateeb
‫عمر الخطيب‬
0120533
Section: 2
Date: 16 / 03 /2014
Objectives:
To Investigate The Relationship Between The pressure And The Temperature For a Saturated Steam in
a Constant Volume Tank. And To verify the Clausius – Claperon Equation.
Apparatus :
Gunt Marcet Boiler
Theory:
𝐝𝐓
𝐝𝐏
=
𝑻.𝑽𝒇𝒈
𝒉𝒇𝒈
T = Abs. Temp.
Vfg = Vg – Vf
Hfg = hf – hg
where :
Results and Calculations:
Gauge Pressure
(bar)
0
1
2
3
4
5
6
7
8
9
10
Absoulte Pressure
0.9
1.9
2.9
3.9
4.9
5.9
6.9
7.9
8.9
9.9
10.9
Graph & Plotting :
Steam Temp .
Increasing Pressure
95
115.2
129.5
140
148.6
156.3
161.9
168.1
172.5
177.1
182.2
Table(1)
Steam Decreasing
Pressure
97.5
117.7
132
142.5
150.3
157.5
163.9
169.5
174.7
179.6
182.2
Mean Temp.
96.25
116.45
130.75
141.25
149.45
156.9
162.9
168.8
173.6
178.35
182.2
Graph Eqaution :
Using Matlab we Get This Equation
y = p1*x^2 + p2*x + p3
Coefficients:
p1 = -6.9843e-05
p2 = 0.16191
p3 = 86.397
Sample Of Calculations :
- Theoretical dT/dP :
The clausius-claperon equation was used for calculating the theoretical dT/dp :
( dT )
(dP )sat
=
T . Vfg
hfg
The calculations of the point of pressure equals 3.9 bar is briefly shown
here :
Table (2 ) :
Saturated Water and Steam Table
P (bar)
3
3.9
4
T (C )
133.5
T*
143.6
By interpolation we get :
T* = 142.59 oC
Vg* = 0.4766 m3/kg
hfg = 2137 kj / kg
Then apply clausius-claperon equation :
( dT )
(dP )sat
=
(142.59+273 ) . (0.4766)
2137
( dT ) / (dP )sat = 0.09269 kelvin / kpa
Vg
0.6057
Vg*
0.4623
hfg
2164
hfg*
2134
-Experimental dT/dP :
The experimental dT/dP represents the slope of T-P diagram , where ( T
in kelvin , and P in kpa ), the slope was estimated by fitting the curve to
2nd degree polynomial , then differentiate the fitting function , these
procedure was done by matlab :
T(p) = p1 . (p2) + p2 . (p) + p3
dT
dP
= 2(p1) . p + p2
dT
=( 2) . ( - 6.9843 . 10-5 ). (390) + (0.16191)
dP
dT
= 0.10743246
Dp
-The error's :
The error can be simply estimated by the following formula :
Error % =
theoretical value - experimental value x 100%
Theoretical value
The calculations of the point of pressure equals 3.9 bar is briefly shown here :
Error % =
0.09269 - 0.10743246
0.09269
x 100%
Error = 15.9 %
Discussion and Conclusion :
Marcet boiler is the device which we use to study the relation in between pressure and
temperature for a water at saturated liquid phase. As we did in the laboratory, we started
heating water with constant pressure until it reached boiling point. Then, closing the valve
which created a constant volume system. Forcing the pressure to increase as the temperature
rises. And thus studying the direct relation between pressure and temperature for water at that
point.
We notice that it is essential to close the valve as we reach boiling point to make sure we are
now in a constant volume process, otherwise pressure would have never increased. Causing the
experiment to be useless.
We also notice that we closed the valve exactly when we reached boiling temperature (95 c at
0.9 bar pressure) and thus keeping water at saturated liquid phase.
After studying the results and plotting the diagram we find that the relation in between
pressure and temperature is directly proportional. The difference between the theoretical
values and the actual values is caused by errors with certain calculated acceptable percentages.