Jennifer Tansey 11/11/11

Introduction / Background A common type of condenser used in steam plants is a horizontal, two- pass condenser Steam enters the condenser through an inlet at the top of the condenser and passes downward over a horizontal tube bundle The tube bundle is made up of individual tubes through which a cooling medium circulates to condense the steam Typically the tubes in the top half of the tube bundle are the “cold,” first pass and the tubes in the bottom half are the “warmer,” second pass

Problem Description The objective of this project is to analyze the tube configuration in a bundle to determine the best arrangement of tubes for the maximum amount of heat transferred to the circulating water The six configurations shown will be analyzed The dark blue denotes the first pass tubes and the light blue denotes the second pass tubes

Current Status – Performing the Analysis Completed the heat and mass transfer algorithm to determine the outlet temperature of the circulating water for the six cases Set and/or calculated all geometric, material and thermodynamic properties Created a velocity profile for the tube bundle, thus allowing a velocity to be calculated for each row of tubes

Current Status – Post-Processing Evaluated all six cases for the same operating conditions and initial parameters, performing six iterations for each pass in each case Solved for the outlet circulating water temperature after the first and second passes for each case Compiled the converged results for the heat flux, interface temperature and outer wall temperature Calculated and plotted the temperature distribution over the length of the tube bundle for both the first and second passes

Current Status – Post-Processing Averaged the circulating water temperatures for each pass to allow comparisons to be drawn among the six cases Weighted the temperatures for the number of tubes in each row for the specific pass Compared the circulating water temperatures for: All first pass tubes Average outlet temperature Average temperature along the tubes All second pass tubes Average outlet temperature Average temperature along the tubes

Current Status – Post-Processing Performed an energy balance to ensure that the iterative algorithm produced accurate results Took into account the change in energy in the system due to: Net loss in energy in the mixture Net gain in energy in the circulating water Net gain in energy in the condensate formed Net gain in energy in the tube walls Showed less than the reasonable 10% error, which can be attributed to the assumptions and simplifications made in the analysis

Current Status – FLOW3D Modeling Created models for all six cases in FLOW3D Currently running the simulations for each case to obtain the velocity profile and evaluate the heat transfer

Next Steps Use the velocity profile created in FLOW3D in Excel to repeat the algorithm with the new velocity profile Analyze and compare the results from the velocity profile created in the algorithm and the velocity profile obtained from FLOW3D Incorporate latest results from FLOW3D and the algorithm into the report Finish writing the report

Milestones / Deadline List MilestoneCompletion DateStatus Submit Proposal9/27/11Completed Create Equation for Heat Transfer in Tubes 10/1/11Completed Perform Analysis for Cases10/15/11Completed First Progress Report10/21/11Completed Model the Cases11/5/11 Running Simulations Second Progress Report11/11/11Completed Analyze Results from Numerical Modeling 11/19/11- Compare Analytical and Numerical Results 11/26/11- Final Draft12/2/11- Final Report12/16/11-