To demonstrate the use of extended surface to improve heat transfer from the surface.
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The experiment aimed to demonstrate improved heat transfer from a surface using extended surfaces like fins. A flat plate heat exchanger and finned and pinned plates were placed in a duct with a fan and heater. The plates' temperatures and temperature differences from ambient air were recorded at various fan speeds. Graphs of temperature difference versus velocity showed finned plates had the smallest temperature difference, demonstrating fins more efficiently transfer heat than pins or flat plates through extended surface area.
To demonstrate the use of extended surface to improve heat transfer from the surface.
- 1. Experiment # 5 Objective: To demonstrate the use of extended surface to improve heat transfer from the surface. Apparatus: Fig5.1 (Free & Forced convection heat exchanger) Procedure: Place the fan assembly on to the top of the duct. Place the flat plate heat exchanger into the duct. Set the heater power control to 75 watts. Allow the temperature ti rise to 800℃, and then adjust the heater power control to 50 watts until a steady reading is obtained. Set the fan speed control to give 1m/s using the thermal anemometer. Recored heated plate temperature (𝑇 𝐻) and the ambient temperature (𝑇𝐴). Repeat this procedure at 2 and 2.5m/s for the flat plate. Repeat the experiment by replacing the flat plate with the finned plate and pinned plate. Plot graphs of velocity against temperature (𝑇 𝐻-𝑇𝐴) for each of the plates.
- 2. Observation: For Fin Type Input power = 50 watt Sr# Air velocity (m/s) Plate temperature 𝑻 𝑯 (℃) Air temperature 𝑻 𝑨 (℃) 𝑻 𝑯-𝑻 𝑨 1 0 58.5 24 34.5 2 1 43.9 24 19.9 3 2 38.5 24 14.5 4 2.5 35.5 24 11.5 For Pin Type Sr# Air velocity (m/s) Plate temperature 𝑻 𝑯 (℃) Air temperature 𝑻 𝑨 (℃) 𝑻 𝑯-𝑻 𝑨 1 0 66 24 42 2 1 50.7 24 26.7 3 2 40.5 24 16.5 4 2.5 37.3 24 13.3 For plate Type Sr# Air velocity (m/s) Plate temperature 𝑻 𝑯 (℃) Air temperature 𝑻 𝑨 (℃) 𝑻 𝑯-𝑻 𝑨 1 0 87.3 24 63.3 2 1 83.6 24 59.6 3 2 76.5 24 52.5 4 2.5 69.3 24 45.3
- 3. Graph: Result: The graph shows that the fin is more efficient then the pin and plate type fins because temperature difference is small then the temperature of fin and palte.