TY  - JOUR
PB  - American Institute of Mathematical Sciences
SN  - 15471063
EP  - 5613
AV  - none
N1  - cited By 2
SP  - 5592
TI  - Conjugated heat transfer of power-law fluids in double-pass concentric circular heat exchangers with sinusoidal wall fluxes
Y1  - 2021///
A1  - Ho, C.-D.
A1  - Lin, G.-H.
A1  - Chew, T.L.
A1  - Lin, L.-P.
JF  - Mathematical Biosciences and Engineering
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85109716205&doi=10.3934%2fMBE.2021282&partnerID=40&md5=aa50fa9a0930c297919a828bf24ab5e8
VL  - 18
N2  - An analytical formulation, referred to as conjugated Graetz problems, is developed to predict the temperature distribution and Nusselt numbers for the power-law fluid flowing in a double-pass concentric circular heat exchanger under sinusoidal wall fluxes. A new design of inserting an impermeable sheet into a concentric tube, in parallel, to conduct recycling double-pass operations has been studied theoretically in the fully developed region, resulting in substantial improvements in the performance of heat exchanger device. The analytical solution was derived using the complex functions by transforming the boundary value problem into ordinary differential equations with the aid of the Frobenius method. The influences of power-law index and impermeable-sheet position on average Nusselt numbers with various designs and operating parameters are also delineated. The theoretical predictions show that the heat transfer efficiency is considerably improved through operating the double-pass device compared to via a single-pass circular heat exchanger (where an impermeable sheet is not inserted). The economic feasibility of operating double-pass concentric circular heat exchanger for power-law fluids is exemplified by the ratio of the heat-transfer efficiency enhancement and the increment in power consumption. The double-pass effect from increasing the convective heat-transfer coefficient can compensate for the rise in power consumption, which serves as important economic advantage of this design. ©2021 the Author(s), licensee AIMS Press.
IS  - 5
ID  - scholars15724
KW  - Boundary value problems; Electric power utilization; Energy efficiency; Heat convection; Heat transfer coefficients; Nusselt number; Ordinary differential equations
KW  -  Analytical formulation; Concentric circular heat exchanger; Conjugated Graetz problem; Conjugated heat transfer; Convective heat transfer Coefficient; Double-pass operation; Economic feasibilities; Heat transfer efficiency
KW  -  Heat exchangers
KW  -  article; feasibility study; heat transfer; prediction
ER  -