Plan of Investigation   

The goals of this experiment were:

1. Determine the overall heat-transfer coefficient
2. Determine the relationship between the overall heat-transfer coefficient and steam pressure, water flow rate, and the inner diameter of the heat exchanger.
3. Determine the reproducibility of the results
4. Compare the experimental values with empirically calculated values
5. Each team member gain proficiency in operating the equipment

Objective 1           

In order to accomplish this objective the equation  Q = UADT_lm  must be used, where U is the overall heat-transfer coefficient.  The cross-sectional area of each pipe, A, will be calculated using the given diameters of each pipe.  The rate of heat transfer in each pipe, Q, will be determined from the equation Q=mc_pDT.  The mass flow rate of water, m, will be measured through experimentation manipulating volumetric flow rate (pipe 1) and orifice pressure drop (pipes 2 and 3) data.  The water temperature difference and the log mean temperature difference, DT and DT_lm, will be determined experimentally at the inlet and outlet of the pipe.  With all of this information, we will calculate the value of the overall heat-transfer coefficient.

 Objective 2 

For each combination of water flow rate and steam pressure for each pipe, a specific overall heat-transfer coefficient will be calculated (as above in objective 1).  The plots of overall heat-transfer coefficient versus water flow rate and overall heat-transfer coefficient versus steam pressure can be produced to determine relationships.  Also, with the given data for inner diameter of each pipe a plot of overall heat-transfer coefficient versus inner diameter of the heat exchanger can be produced.

Objective 3

 Reproducibility in this experiment will be determined by doing multiple runs and multiple trials for each setting where measurements were taken.  These measurements will be compared against each other to check to see if they are close within reasonable error.

Objective 4

From the data collected in the laboratory the overall heat-transfer coefficient will be calculated from the equation Q = UADT_lm.  Based on the plots created from the completion of objective 2, expected trends of these plots will be formulated using an equation of overall heat-transfer coefficient as it relates to local heat transfer coefficients and other dimensional relationships.  Also, theoretical overall heat-transfer coefficients will be calculated from the conditions of each pipe and compared with experimental values.

Objective 5 

This objective will be completed by ensuring that every team member is present during the lab inspection to fully understand the operation of the heat exchange apparatus.  Each team member will actively take part in experiment operations other than his/her given assignment. 

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