Prepared to: Dr. Maohong Fan
Subject: Heat Transfer from Steam to Water
Date: 11/01/2013
Summary:
The objective of this experiment was to investigate the overall heat transfer ( Uₒ ) for the external heat exchanger at two different water circulation rates by using two methods “ Heating Liquids in Tank Storage ” and “ Corning Heat Exchanger “ . Briefly, the measurements were done by changing the volume flow rate between 40 lbm/min and 70 lbm/min for the first part of the experiment which was “Heating Liquids in Tank Storage”. However, for the second method, the measurements were taken by changing the flow rate for the second part, which was “Corning Heat Exchanger “, between 2, 4, 6, 8 and 10 (gallon per minute). …show more content…
Next, the arrow icon was clicked to begin measuring temperatures. After that, the water drain valve was closed tightly. Next, the water flow was set to 2 gpm, and the steam valves were opened. Flow rate oscillated up and down during the process of heating, so adjustment was required to maintain the desired flow rate. Then, temperatures were recorded if stabilization and no significant changes occurred. Next, the tubes were examined, and the transition between boiling and non-boiling heat transfer was observed. Finally, the above steps were repeated exactly for flow rates of 4,6,8, and 10 …show more content…
Dev
Heat Transfer Coefficient 241.917 316.648 335.923 298.163 49.65411652
6 gpm week 1 week 2 week 3 Average(btu/(hr ft2 oF)) Std. Dev
Heat Transfer Coefficient 394.657 453.668 452.918 433.7476189 33.85553973
8 gpm week 1 week 2 week 3 Average(btu/(hr ft2 oF)) Std. Dev
Heat Transfer Coefficient 460.247 482.415 444.368 462.343 19.11007224
10 gpm week 1 week 2 week 3 Average(btu/(hr ft2 oF)) Std. Dev
Heat Transfer Coefficient 467.816 510.242 465.396 481.151 25.22256403
From Table.5, it is obvious that when the flow rate increases, the overall heat transfer coefficient increases as well. However, applying the experiment seems to fail in finding an assumption for the high difference in standard deviation values among different flow rates. It might be a result of the difficulty of measuring the flow rate using the rotameter. It is recommended to check the flow rate constantly to make sure the flow is maintained as possible.
Table.6 The confidence intervals analysis for different flow rates in 3 weeks at 2 gpm Week 1 Week 2 Week 3
Upper confidence interval 218.0811 257.2200