1. Equipment
• The shell and tube heat exchanger (see figure 2) consists of a four pass tube fitted within a shell casing with cold water circulating through the tube and hot water flow trough the shell.
• Two flow meters, one fitted at the inlet of the heat exchanger for the hot water am the other fitted at that of the cold water. How rate is read by the position of the float on the graduated scale (read from the ring).
• Valves for adjusting the cold wan hot water flow rate.
• Pipes for the cold and hot fluid.
• Hot and cold water supply. •
• Four thermocouples for measuring the temperature at the inlets and exits of both cold and hot fluids, one for measuring the ambient temperature.
• 1 Jenco digital thermometer and 1 Jenco thermocouple switch.
2. Operating Procedure
a) Be familiar with the different parts of the experimental equipment.
b) Turn on the cold and hot water taps.
c) Turn valves for the cold and hot water at an initial flow rate (approximate 15 L/min for cold water). Make sure that all the water passes through the flow meters (turn off one of the valves in each water supply line).
d) Water for a couple of minutes before reading the data.
e) Take the temperature reading for thermocouples 1 to 5 by press the Jenco thermocouples buttons.
f) Repeat c) to e) for 5 different flow rate combinations.
3. Data Collection
|
Run/Quantities
|
Qhot (L/min)
|
Qcold
(L/min)
|
Thot
inlet
|
Tcold
inlet
|
Thot
outlet
|
Tcold
outlet
|
|
1
|
|
|
|
|
|
|
|
2
|
|
|
|
|
|
|
|
3
|
|
|
|
|
|
|
|
4
|
|
|
|
|
|
|
|
5
|
|
|
|
|
|
|
4. Data Analysis
a) Write down the mass and energy equations.
b) Calculated the energy loss from each run and table the results.
c) For run 3, try to calculate the enthalpy changes of the water by using 1) tables and 2) formula using constant specific heat.
d) Select run5, assuming the temperature for the exit cold fluid is not measured and there is no energy loss, calculate the exit temperature of the cold fluid, compare this with the measured results, and discuss the where the heat loss can occur.
e) Give a brief discussion on the possible temperature change of hot and cold waters along the heat exchanger.
1.0 EXPERIMENTAL DATA:
Room temperature: 15°C
|
Run/Quantities
|
Qhot
(L/min)
|
Qcold
(L/min)
|
Thot
inlet
|
Tcold
inlet
|
Thot
outlet
|
Toutlet
outlet
|
|
1
|
1.5
|
1
|
47
|
15
|
30
|
32
|
|
2
|
3
|
3
|
42
|
15
|
22
|
22
|
|
3
|
4
|
7.5
|
41
|
14
|
23
|
23
|
|
4
|
5.5
|
10
|
41
|
14
|
22
|
24
|
|
5
|
6.5
|
11
|
47
|
14
|
26
|
28
|