TY - GEN
T1 - Effectiveness of parallel flow microchannel heat exchangers with external heat transfer and internal heat generation
AU - Mathew, B.
AU - Hegab, H.
PY - 2009
Y1 - 2009
N2 - In this paper the thermal performance of balanced parallel flow microchannel heat exchangers subjected to external heat transfer and internal heat generation have been numerically analyzed. The governing equations were numerically solved to obtain the axial temperatures of the fluids. The effectiveness of each fluid was determined using the inlet and outlet temperatures obtained from the numerical analysis. Moreover, the heat transferred between the individual fluids and the ambient as well as that between the fluids were numerically determined. The effectiveness depended on NTU, ambient temperature, thermal resistance between the ambient and the fluids, and the internal heat generation. When NTU is zero, the effectiveness depends only on the internally generated heat. At a particular ambient temperature and NTU the effectiveness of the hot and cold fluids degraded and improved, respectively, with increase in the internally generated heat. On the other hand with increase in ambient temperature the effectiveness of the hot and cold fluids decreased and increased, respectively, for a specific amount of heat generation. The model developed in this paper has been validated using existing models which consider the individual effect of external heat transfer and internal heat generation on the performance of parallel flow microchannel heat exchangers.
AB - In this paper the thermal performance of balanced parallel flow microchannel heat exchangers subjected to external heat transfer and internal heat generation have been numerically analyzed. The governing equations were numerically solved to obtain the axial temperatures of the fluids. The effectiveness of each fluid was determined using the inlet and outlet temperatures obtained from the numerical analysis. Moreover, the heat transferred between the individual fluids and the ambient as well as that between the fluids were numerically determined. The effectiveness depended on NTU, ambient temperature, thermal resistance between the ambient and the fluids, and the internal heat generation. When NTU is zero, the effectiveness depends only on the internally generated heat. At a particular ambient temperature and NTU the effectiveness of the hot and cold fluids degraded and improved, respectively, with increase in the internally generated heat. On the other hand with increase in ambient temperature the effectiveness of the hot and cold fluids decreased and increased, respectively, for a specific amount of heat generation. The model developed in this paper has been validated using existing models which consider the individual effect of external heat transfer and internal heat generation on the performance of parallel flow microchannel heat exchangers.
KW - Effectiveness
KW - Heat Exchangers
KW - Heat transfer
KW - Microchannels
KW - NTU
UR - http://www.scopus.com/inward/record.url?scp=70349087410&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70349087410&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:70349087410
SN - 9780791848487
T3 - 2008 Proceedings of the ASME Summer Heat Transfer Conference, HT 2008
SP - 175
EP - 184
BT - 2008 Proceedings of the ASME Summer Heat Transfer Conference, HT 2008
T2 - 2008 ASME Summer Heat Transfer Conference, HT 2008
Y2 - 10 August 2008 through 14 August 2008
ER -