• ELMUATAZ MOFTAH
• Ahmad Abdelaly

In Heat Exchangers text books, the derivation of the effectiveness( )and the number of transfer units( NTU ), (ε-NTU) relations, are based on figures which are difficult to understand and the physical meaning of the steps in the derivation is unclear. The NTU-Effectiveness heat exchanger design formula for the double pipe heat exchanger in parallel flow arrangement is derived from the first principles. Energy equations of parallel flow arrangement for both the hot and the cold fluids are determined. The actual rate of heat transfer for parallel flow arrangement along with the heat exchanger effectiveness are stated. The relationship between the effectiveness ( )and the number of transfer units( NTU ) for the double pipe heat exchanger in parallel flow arrangement is plotted.

exchanger, effectiveness, parallel flow, transfer units, double pipe.

"Derive the NTU-Effectiveness Formula for the Double Pipe Heat Exchanger in Parallel Flow Arrangement", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 3, page no.1-6, March-2018, Available :http://www.jetir.org/papers/JETIR1803001.pdf

"Derive the NTU-Effectiveness Formula for the Double Pipe Heat Exchanger in Parallel Flow Arrangement", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 3, page no. pp1-6, March-2018, Available at : http://www.jetir.org/papers/JETIR1803001.pdf