# Analysis of effectiveness of parallel flow microchannel heat exchangers with heat transfer from surroundings

T. J. John, B. Mathew, H. Hegab

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

## Abstract

The performance of a parallel flow micro channel heat exchanger (MCHX) is examined in this paper with the help of a mathematical model developed for this study. The thermal performance of a balanced parallel flow MCHX is numerically evaluated with the effect of heat transfer from the surroundings taken into consideration. Two non-dimensional governing equations are developed for modeling this MCHXPF. This model also considers a case in which the temperature of surrounding that is adjacent to the hot fluid channel is assumed to be different from that in contact with the cold fluid channel. The equations are numerically solved using the Runge-Kutta-Fehlberg method. MATLAB software is used to develop the program for solving the equations that constitute this model. The axial temperatures along both channels are obtained upon numerically solving the governing equations. The effectiveness of each fluid is then calculated using its inlet and outlet temperatures. The heat transfer between the fluids and that between the surrounding and each fluid are also numerically calculated using the axial temperatures of the fluids. The effectiveness of the fluids depends on the NTU, temperatures of the surroundings, and the thermal resistance between the individual fluids and their corresponding surrounding. When the heat transfer from the surrounding and the respective fluid is increased the effectiveness of the hot fluid decreased and that of the cold fluid increased. The temperature of the surroundings will determine the direction of heat transfer between the individual fluid and its surrounding. When the temperature of the surroundings is higher than the inlet temperature of the hot fluid then there would be degradation of the effectiveness of the hot fluid and an improvement in the effectiveness of the cold fluid. And the opposite trend happens when the temperature of the surroundings are lower than the inlet temperature of the cold fluid.

Original language English Proceedings of the ASME Summer Heat Transfer Conference 2009, HT2009 629-636 8 https://doi.org/10.1115/HT2009-88230 Published - 2009 Yes 2009 ASME Summer Heat Transfer Conference, HT2009 - San Francisco, CA, United StatesDuration: Jul 19 2009 → Jul 23 2009

### Publication series

Name Proceedings of the ASME Summer Heat Transfer Conference 2009, HT2009 1

### Conference

Conference 2009 ASME Summer Heat Transfer Conference, HT2009 United States San Francisco, CA 7/19/09 → 7/23/09

## Keywords

• Effectiveness
• Heat exchangers
• Microchannel
• NTU
• Parallel flow channels

## ASJC Scopus subject areas

• Fluid Flow and Transfer Processes

## Fingerprint

Dive into the research topics of 'Analysis of effectiveness of parallel flow microchannel heat exchangers with heat transfer from surroundings'. Together they form a unique fingerprint.