Heat Exchanger Lab Report

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HEAT EXCHANGER  

AKALANKA TENNAKOON

Abstract

Using a shell and tube heat exchanger, several experiments were conducted to observe heat transfer. Using Energy balances, the loss of heat was calculated. For the two configurations used, current and concurrent flow, the thermal efficiency (U) and heat exchange efficiency (ε) were calculated. From analyzing data, it was deemed that counter current configuration is thermally efficient than the concurrent configuration.

Experimental Procedure

First, all valves supplying water in and out of the heat exchanger were closed. Then all the main switches were turned on and the set point for the hot water was set at 300C. Then the cold water supplying valve was opened and it was set to supply 1.0 L/min of water. Throughout the experiment cold water supply was left unchanged.  For the first part of the experiment water flow was set in counter current direction and the measurements were taken. Hot water flow was varied changed to 2.0, 2.5 and 3.0 L/min respectively while keeping the temperature of the hot water flow constant. Then the same flow rates were varied in the same manner to take measurements at 400C and 500C.

After that the cold and the hot flow were set in the concurrent configuration and the same trials were conducted by varying flow and temperature while keeping one constant and the measurements were taken. Total of 18 trials were conducted for both configurations.

Measured and Calculated Data

Stainless steel tube
            outer diameter (do) = 6.35mm
            wall thickness = 0.6mm

Outer acrylic tube

Inner diameter (di) = 39mm
wall thickness = 3.0mm

Length of tube = 144mm

Table 1: Measured Data for Counter Current Flow

Table 2: Hot and Cold Water Heat Rate for Counter Current Flow.

Table 3: Measured Data for Concurrent Flow