الفهرس Only 14 pages are availabe for public view
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Abstract
Extended or finned surfaces are widely used in compact heat exchangers to reduce the thermal resistance of air or gas-side flows. Besides increasing the effective heat transfer surface area, geometrically modified finned surfaces also improve the heat transfer coefficient by altering the flow field. Plate fm heat exchangers have such properties and promote relatively high thermal performance. They are also attractive for their simplicity of manufacture and ease of use.
The present work deals with the modeling of a plate fm heat exchanger used in the ethylene plant of Sidi Kerir Petrochemicals Company (SIDPEC) located in Alexandria, Egypt, in this exchanger there is super extraction of the seven different cold streams to cool the propane refrigerant which is the main refrigerant of the ethylene plant.
A mathematical model was developed and used to evaluate the performance of the heat exchanger and to predict the outlet temperatures of the hot and cold streams leaving the exchanger. The model was developed with some major assumptions such as no fouling, no pinch points occur, and others.
The model was tested by comparing the theoretical results generated by the model with actual running data of the exchanger, the model results were compared with three different operating conditions, these correspond to running the exchanger at different plant loads. The three situations represent running loads of 100% (design case), 96%, and 85% loads, the results of the comparison had shown remarkable agreement between the model results and the real exchanger data, also the model was used to verify the major assumptions and showed that the assumptions are acceptable.
Finally a sensitivity analysis was carried by assuming variations in the model results by varying the process and design variables, this had shown that the cold streams inlet temperature has the most drastic effect on running the exchanger’s model.