Thermodynamics And Heat Transfer Analysis: Shell And Tube Heat Exchanger
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College of Engineering
MHT 314: Thermodynamics and Heat Transfer Analysis
Laboratory Experiment 5
Shell and Tube Heat Exchanger
March 5, 2015 Introduction:
In lab 5 we were working with a heat exchanger. It is used to transfer energy in the form of heat from on fluid to another. Two input fluids of different temperatures are put into it and temperature is transferred between fluids since they run next to each other. There are multiple configurations for all sorts of applications. Figure 1: Top View of HT33 Shell and Tube Heat Exchanger
Each configuration just refers to how they move relative to each other.…show more content… This difference becomes less as it travels the length of the heat exchanger. For counter flow heat exchanger, fluids warm up or cool down at roughly the same rate as it travel the exchanger. In counter flow the temperature difference is close to constant.
The following are equations to help us understand this process better:
The overall resistances can be calculated using:
For the hot water:
For the cold water:
Heat exchanger effectiveness:
Test Methods and Procedures:
For this experiment a HT30X Heat exchanger services unit was used along with an HT33 shell and tube heat exchanger. This device included four K-type thermocouples at the hot and cold inlet and outlets. The procedure for the laboratory is listed below:
1. Set the cold water pressure regulator. Adjust the knob until a flow rate of 1.00 liters per minute is established. Lock down this setting.
2. Prime the hot water circuit. Do not let the water level fall below the height of the priming vessel to prevent air from entering the system.
3. Set the computer software to countercurrent flow and maintain a hot water temperature of 60°F.
Figure 2: Concurrent flow
Figure 3: Counter current flow
RUN m_cw m-ht Th in Th out Tc in Tc out l/s l/s ˚C ˚C ˚C ˚C
1 1 3 60.7 56.5 15.9…show more content… This follows logically since more cold water is delivered to carry away heat per unit of time. Additionally increased flow rate results in more turbulent flow. This also increases the heat transfer rate.
Part A of the lab consisted of using a simple shell and tube heat exchanger. We then were able to heat a stream of cold fluid by indirect contact with the fluid stream of a different fluid that had a higher temperature. This also resulted in the cooling of the warmer fluid.
In Part B we were introduced the most important characteristic of the heat exchanger. This was the method for calculating the overall heat transfer coefficient for a shell and tube exchanger. We did notice that there was no noticeable difference in the heat transfer rate between parallel flow and counter current flow. This was not the result we expected and went against the theory we had learned. Counter current flow should theoretically show enhanced heat transfer